Vendor Listing Much of this list is taken from the Doyle group vendor list Here are some vendors we've found over the years for various things: Buyers guides Physics Today Buyers Guide CERN Courier Buyer's Guide ThomasNet - Extensive vendor search engine Parts Permanent Magnets KJ Magnetics Amazing Magnets Dura Magnets Storch Magnetics Electron Energy Shin-Etsu MCE ACH Magnetics Dexter Magnetic Technologies Magnet Wire MicroDyne SW Wire Putnam Plastics - Will e.g. kapton-insulate custom wires Cooner Wire MWS Wire Industries - Microsquare wire Radiation equipment Atlantic Nuclear - radiation safety: shielding, radiation meters, dosimetry Ludlum Measurements - exhaustive assortment of survey meters Canberra - radiation measurement and safety supplies, including radioisotope samples Hardware/Machining Supplies/Fasteners McMaster MSC - When McMaster just won't do Small Parts Small and/or obscure parts RAM mounts - Mounts for scopes and other instruments. Vlier - Screws with Springs inside and more. SunSource Local 80/20 supplier. Fiero Fluid Power Local 80/20 supplier. Air Incorporated - 80/20 supplier. Phone: 800-341-2800. Best to have the cut numbers and location codes (from an 80/20 catalog) ready for any anchor fastener counterboring, etc., before you call. Amazing Magnets - Permanent magnets KJ Magnetics - Large selection of rare-earth magnets. Olander - Helicoils, including phosphor bronze and other specialty materials. Before ordering, it helps to have a part number from a helicoil manufacturer , such as http://www.chrislynninserts.com/helicalpages/AMERbulkQTY.htm Chrislynn Inserts or Emhart Teknologies . If you need non-magnetic helicoils quickly, MSC sells titanium helicoils in many common sizes. Solon Manufacturing Belleville spring washers in specialty materials, including phosphor bronze United Titanium Titanium fasteners Mutual screw Brass (C260) and silicon bronze fasteners ET Fasteners PEEK screws and other exotic plastics. Can even get them vented! Razor Blades Cadence Inc. , formerly Specialty Blades, has a large selection of razor blades in all shapes and materials. Glassware Chemglass Things like glassware with vacuum-grade threads. Sigma-Aldrich Fittings Swagelok Maryland Metrics Where you get the dumb Serto fittings for Sirah lasers. Materials Vibration Isolation http://www.earsc.com/ EAR Specialty Composites =⇒ Jan's smelly Blue Stuff = #6309-0026 Ablation target preparation and testing Applied Test Systems - high-end materials testing and furnaces Futek - Load cells and other sensors MTI Corporation - relatively inexpensive materials science research supplies (furnaces, temp. controllers, crucibles, gloveboxes, benchtop presses, diamond blade saws, ball mills, nanopowders…); equipment seems generally reliable, but technical support is of little help. Renco Corporation - sells glovebox gloves Thermo Scientific - general lab supplies, including furnaces Chemicals and materials Alfa aesar - chemical supplier American Elements – pretty much the whole periodic table, but don't get too excited - they don't carry a lot of what they list. Plasmaterials Process Materials Refrac systems - Diffusion bonding, hot-pressing MP Biomedicals - Cheapest thorium metal powder ever, while supplies last… Fisher Scientific Sigma Aldrich Strem Chemical Spectrum Chemical VWR Pfaltz and Bauer Ceramics See also: Chemicals_and_materials McMaster Cercom Ceramics CoorsTek ceramic tubes etc. Kyocera - expensive Marketech - will do almost anything, but take ~1 week to send quotes Orton Ceramics - supplier for hobby or industrial ceramic making, carries pyrometric cones Progressive Technology - ceramic tubes etc. Stratamet - will do small custom jobs. Talk to Mark Wesson. Tell him Sarah (Bickman, ex-DeMille group) sent you. Zircar Zirconia - refractory ceramics in various forms, mainly alumina and zirconia; also some furnaces Technical Products - Large selection of ceramics and plastics. Great selection of Macor. Astro Met Morgan Technical Ceramics Cadence Inc. , formerly Specialty Blades, has a large selection of fancy razor blades, including ceramics. Piezo Crystals Polytec PI, aka Physike Instrumente Piezo Systems Metals See also: Chemicals_and_materials ESPI - expensive, but has everything Goodfellow Rembar - Good for Tantalum, Tungsten etc Hagstoz - Gold and precious metals, usually cheap Refining Systems - Gold and precious metals Hauser and Miller - Even cheaper gold and precious metals Allfoils - “UHV Aluminum Foil” Sophisticated alloys Parker Steel - Metric metals (not just steel). Tell Gary Bartlett that Stan sent you. Copper.org Data on copper alloy compositions Copper and brass sales - THE copper and brass supplier. Doesn't always sell small quantities. Ask for Jeremy Jennings, First.last@thyssenkrupp.com Sequoia Copper and Brass - Cheap copper and brass. Sells small quantities at reasonable prices, but might take a while. Online Metals - Good selection, fast shipping, reasonable prices on most things. DO NOT BUY COPPER HERE… the price is inflated by a factor of 2-3 compared to Sequoia or Copper and Brass. McMaster - Good selection, reasonable prices. Don't buy if you really need a specific alloy of a metal, since they never provide any sort of material certification. Brunner Enterprises - Good source for anodized aluminum. Turner Steel - Steel Ed Fagan - Invar, Molybdenum, Tungsten, Tantalum, Nickel Admiral Metals - Aluminum, S.S., brass, beryllium, copper Yarde Metals - Large diameter tubes Tube Service - Large diameter tubes T.W. Metals - Tubing, aluminum, stainless, nickel Permendur Arnold Magnetics More than Metals Eagle Alloys - also does inconel and monel Goodfellow CarTech Plastics and Composites McMaster Technical Products - Large selection of ceramics and plastics. K-Mac Plastics Curbell Plastics Patriot Plastics Adhesives K. R. Anderson Ellsworth Optics Essentials Thorlabs CVI New Focus Newport - Excellent damage threshold for price Alpine Research Optics - Harmonic separators other optics w/ great specs and low prices. Speak with Mike Ellison. Casix - dirt cheap, long lead times? conoptics - Isolators Edmund optics Optosigma - windows Esco Products -unusually fast and inexpensive for custom optics jobs, proven reliable. Also good selection of stock optics, 'especially cheap windows, lenses, etc' Precision applied products - windows, coatings, lenses, mirrors. Specialty Fiberoptic Systems - Custom fiber optic bundles, including high vacuum, non-ferrous, high NA. Great prices. Rocky Mountain Instruments - custom coatings, custom lenses, UV specialists, fast service Research Electro Optics - High end optics Advanced Thin Films - custom jobs Tower Optical - waveplates EO tech - Isolators PI action - CCD cameras Semrock - Filters + MaxMirror Intor - cheap interference filters Uniblitz - shutters Andover - colored glass filters Omega - stock + custom interference filters Coherent - Tell them you want the 'Family Discount' Get 20% Off all laser measurement products. OFR - fiber optics and isolators Technical Glass - Quartz rods, discs, tubes, etc. NEOS - AOMs Intraaction - AOMs St. Gobain Crystals - custom crystalline optics Standa - mostly optomechanics Expla - laser systems, OPOs, some components Optometrics - diffraction gratings Argyle Optics - custom stuff might be cheap but standard optics are also custom made = expensive Vere Optics lab accessories Tempotec - Chinese Company…like Casix or casix affiliate? Mightex - CCD cameras Siskiyou - Unusual optomechanics: top-drive flexures stages, etc. Optical fiber fault checker Laser Components - Both custom and stocked cavity mirrors Photonic Cleaning Optics cleaning supplies for astronomy, including 'First Contact' goop. Nihon Tokushu Kogaku Jushi Fresnel lenses up to f/0.2 Fresnel Tech Custom and specialty Fresnel lenses Custom Scientific Flats, windows, fibers and coatings. They made the EDM field plates: 18” x 8”, 5 lambda flat with conducting AR coatings. Thin Film Labs Custom AR coating, other kinds of wacky coatings, *extremely fast* turnaround. Yale recommended. LayerTec Cheap yet good quality cavity mirrors EO Space Fiber phase modulators, with V_pi as low as ~ 5 V ! NSG America all-glass GRIN fiber collimators Apogee Instruments Low-noise CCD cameras Electrophysics Objective lenses for C-mount cameras/imagers Fiber Optics Store - Various fiber optics supplies. Sells ] for cheap, which are very useful for aligning coupling/collimating lenses. Laser Diodes Sacher Eagleyard - AR coated laser diodes Roither Lasertechnik - Laser diodes, LEDs, Optics, Toptica - Lasers, AR Coated Diodes Intelite/Meshtel - Non-AR Coated Diodes, Sacher gets some of their diodes here before AR Coating Power Technology - Single Mode Diodes, TAs, DFBs and more m2K - Tapered Amplifiers and More FLT Laser - Huge selection including DFBs from many suppliers in addition to their own line Nanoplus - DFBs RPMCLasers - Single Mode diodes and more, not AR Intenseco - I think only Multimode / Broad Area qPhotonics - Single Mode Laser diodes and more. 895-915 nm and 1050-1080 nm diodes are offered with AR coating (for $300-400) Opnext - Make a lot of Non-AR coated diodes Axcel Photonics - Common NIR Laser Diodes Lab351 - Russian Laser Diode Company Wavelength Electronics - Cheap and convenient current temperature controllers. Oclaro (formerly Bookham) - High power (600mW) 980nm pump laser modules, fiber coupled. EM4, Inc. - High power (600mW) 980nm pump laser modules, fiber coupled. Photonic Products - distributor for Opnext, Ondax, Sony and SANYO ILX Lightwave Axcel Photonics Near/Mid-IR Lasers Optics Lohn Star Optics IGP Photonics LTW Lasers AcuLight Laser Dye Exciton PMT Hamamatsu PMT contact Rich at (908) 252-7728 Fax: (732) 537-3678 Optical detectors, PMTs Electron Tubes Burle Hamamatsu RoentDek - Makes MCPs and readout electronics DelMar Photonics - MCP Beam Imaging - MCP directly coupled to a camera through a fiberoptic rod. Primer on MCPs (broken link) Coatings, deposition AIMCAL - Assoc. of Metallizers, Coaters Laminators FAQ (broken link) Spectrum coatings Helia Photonics - Ion-assisted deposition Ionedge - Ion-assisted deposition Thin Films Inc. - Sputtering, Evaporation, Lithography - flexible small shop Thin Film Labs - specialize in optical component coatings Koral Labs - thin film deposition + vacuum furnace stuff IJ Research - ceramics, deposition, lithography - flexible, associated with USCB, IIRC Sophisticated alloys - deposition targets, but “we don't do coatings” Process Materials (broken link) Sputtering target suppliers Sputtering Materials Inc Electroplating Paramount Metal Finishing - Rack Electroplating - reasonable prices http://www.amzmfg.com/index.asp AMZ Manufacturing - High quality electroplating Metal Finishing Technologies - Various plating services Epner Technology - Fancy gold electroplating - expensive, high-tech Diamond-Turned Optics II-VI Infrared - good CO2 optics; possibly worst url ever Corning NetOptix - used to be OFC Diamond Turning Kugler - German precision optics company, ja Kaleido Technology - in Denmark Electronics Essentials Mouser Electronics Digikey Online Components Analog Devices Apex Microtechnologies - High Voltage/Power Op-Amps Lansing Instruments - Really Nice Enclosures Emco High Voltage - DC-DC Converters Allied Electronics L-Com - Cheap connectors/adaptors Powell Electronics - Hard to find/out of stock stuff Meritronics - Board Assembly Pasternack - Quality BNC cables Acopian - Supreme power supplies Krohn-Hite Ultra-precise DC sources other precision stuff Phoenix of Chicago Good selection of connectors. Non-magnetic D-sub connectors. FCT Non-magnetic connectors of all sorts. Souriau Non-magnetic D-sub connectors with crimp contacts. Proto-advantage SMT to DIP adapters Newark Lots of things, including hearing-aid microphones for supersonic beam characterization. Flex Cable Water-cooled cables. Sensors Micromagnetics Magnetoresistance-based B-field sensors Honeywell Anisotropic magnetoresistance (AMR) magnetic sensors. Noise is 1 uG/rt-Hz @ 10 Hz. ~20$ each. Vacuum Manuals from lots of companies for lots of old pumps controllers Essentials LDS Vacuum Shopper - fast + cheap. 'This should be your first stop for vacuum stuff!' Duniway stockroom Cheap, good selection of used vacuum equipment Huntington Kurt J. Lesker MDC A N Corp - Feedthroughs, flanges etc. Specialty InstruTech - Makes compact, digital convectron and ion gauges at good prices. AVS Technical Resources - Useful calculator for conversion factors, pump/gauge ranges Varian High quality dry scroll and turbo pumps at competitive prices. Now owned by Agilent. Edwards Turbo and dry scroll pumps. Scrolls are quieter than Varian and often cheaper; also have a chemical-resistant model. Precision Cryo Ask for Dick Gummer. They made the EDM beam source chamber. Kimball physics - special (cool) chambers Sharon - custom chambers Key High vacuum generators Best quality UHV all-metal valves. Insulator Seal - Feedthroughs. Owned by MDC. Apiezon Greases and Waxes EVAC Vacuum - Unique! Standard QF/ISO hardware, but made out of glass(!), aluminum, etc. accuglass products - Unusually nice selection of feedthroughs, in-vacuum electrical connectors, hardware, etc. Prices better than Lesker. Also have in-vacuum RF/microwave parts. MPF Products - Similar to accuglass for electrical feedthroughs, but also has nice selection of viewports Atlas UHV - UHV grade welded aluminum vacuum chambers. Made the EDM interaction chamber. Heating Tapes Minco heaters Foil heaters with kapton copper, non-magnetic All Foils UHV clean aluminum foil Pfeiffer Vacuum Cryogenics Cryodepot Cryofab Janis Lakeshore Cryotronics Oxford Instruments Cryomech - Pulse tube coolers. Calgon Carbon - Activated charcoal for Sorbs discountcryo - Great selection of cryo accessories, including small hand dewars. Metalized Products - Superinsulation (NRC-2) Gases and Flow Control MKS Instruments - Flow controllers. Laminar Technologies - Sells used MKS flow controllers. The Harvard cleanroom manager (Noah Clay) claims that used flow controllers are better (since they are screened for infant death), and of course they are cheaper. Alicat Scientific - Better flow controllers than MKS (in particular, they do their own temperature correction). Have ultra-low-flow models. Generally not suitable for corrosives. RF/Microwave Essentials Mini-Circuits Everything. Dudley Lab Used amplifiers, test equipment, etc. Stealth Amplifiers. Empower RF Amplifiers. Ophir Amplifiers. Quasi-Optical Photonics Innovation Center Thomas Keating Ltd mm-wave Microwave Components Quinstar - Large selection of waveguide and coax, ask for Sage Kuno Miteq - Largest supplier (and stock) but more expensive Penn Engineering - Raw waveguide stock, flanges Atwall - Raw waveguide stock, flanges UBS - Raw waveguide stock, flanges Actuators and Motion Control Newmark Systems Arrick Robotics Parker Hannfin Motion Control Cyber Research Motion Control Techno Linear Motion Systems Velmex Low cost, large travel motorized stages Aerotech - Precision stages Noliac - Large selection of piezos, including rings Micromechatronics - Re-seller for Noliac, other piezos.
Contents 1 Trust-Oriented Composite Service Selection with QoS Constraints Trust-Oriented Composite Service Selection and Discovery Finding K Optimal Social Trust Paths for the Selection of Trustworthy Service Providers in Complex Social Networks A Subjective Probability Based Deductive Approach to Global Trust Evaluation in Composite Services The Prediction of Trust Rating Based on the Quality of Services Using Fuzzy Linear Regression A Heuristic Algorithm for Trust-Oriented Service Provider Selection in Complex Social Networks Context Based Trust Normalization in Service-Oriented Environments Trust Transitivity in Complex Social Networks Subjective Trust Inference in Composite Services The study of trust vector based trust rating aggregation in service-oriented environments 2 1 Yan Wang http://web.science.mq.edu.au/~yanwang/ Trust-Oriented Composite Service Selection with QoS Constraints Lei Li, Yan Wang,Ee-Peng Lim Journal of Universal Computer Science , vol. 16, no. 13 (2010), 1720-1744 Abstract: In Service-Oriented Computing (SOC) environments, service clients interact with service providers for consuming services. From the viewpoint of service clients, the trust level of a service or a service provider is a critical factor to consider in service selection, particularly when a client is looking for a service from a large set of services or service providers. However, a invoked service may be composed of other services. The complex invocations in composite services greatly increase the complexity of trust-oriented service selection. In this paper, we propose novel approaches for composite service representation, trust evaluation and trust-oriented composite service selection (with QoS constraints). Our experimental results illustrate that compared with the existing approaches our proposed trust-oriented (QoS constrained) composite service selection algorithms are realistic and enjoy better efficiency. Key Words: composite service, composite service selection, composite service representation, trust evaluation, Monte Carlo method 1 Introduction Service-Oriented Computing (SOC) Quality of Service (QoS) the reputation-based trust service composition + trust Open problem: trust-oriented composite service selection 1. The proper definition of the graph representation of composite services including both probabilistic and parallel invocations is still lacking. 2. subjective probability 3. no proper mechanism exists for evaluating the global trust of a composite service with a complex structure over service components with different trust values. 4. Call for effective algorithmsfor trust-oriented composite service selection the work of this paper: --first present the service invocation graph for composite service representation. --propose a trust evaluation method for composite services based on Bayesian inference -- propose composite service selection algorithms based on Monte Carlo method. The organization of this paper: 1) Section 2 reviews existing studies in service composition, service selection and trust management. 2)Section 3 presents our proposed composite services oriented service invocation graph. 3) Section 4 presents a novel trust evaluation method for composite services. 4)Section 5 proposed Monte Carlo method based algorithms for trust-oriented composite service selection (with QoS constraints). 5) Section 6 presents experiments for further illustrating the properties of our models. 6) Finally Section 7 concludes our work. 2 Related Work QoS-aware Web service selection mechanisms: -- linear programming -- Multi-Constrained Optimal Path (MCOP) problem -- the drawbacks of existing approaches: none of these works addresses any aspect of trust 3 Service Invocation Model the aim of this section: present the definitions of our proposed service invocation graph for representing the complex structures of composite services 3.1 Composite Services and Invocation Relation Six atomic invocation relationsare depicted as follows and in Fig. 1. -• Sequential Invocation -• Parallel Invocation: -• Probabilistic Invocation: -• Circular Invocation: -• Synchronous Activation: -• Asynchronous Activation: 3.2 An Example: Travel Plan 3.3 Service Invocation Graph Definition 1. The service invocation graph (SIG) 4 Trust Evaluation in Composite Services the purpose of this section: trust evaluation models for composite services the outline of this section: -- Section 4.1 describes a trust estimation model to estimate the trust value of each service component from a series of ratings according to Bayesian inference -- Section 4.2 proposes a global trust computation model to compute the global trust value of a composite service based on the trust values of all service components 4.1 Trust Estimation Model subjective probability Bayesian inference 4.2 Global Trust Computation in Composite Services Our goal: to select the optimal one from multiple SEFs (service execution flows) in an SIG aiming at maximizing the global trust value of SEF 5 Trust-Oriented Composite Service Selection the aim: the trust-oriented (QoS constrained) service selection algorithm is applied to find the most trustworthy SEF (satisfying QoS constraints). 5.1 Monte Carlo Method Based Algorithm (MCBA) in Trust-Oriented Composite Service Selection without QoS Constraints divide and conquer author's idea: propose a Monte Carlo method based algorithm (MCBA) to find the optimal SEF. Monte Carlo method: 5.2 QoS Constrained Monte Carlo Method Based Algorithm (QC MCBA) in Trust-Oriented Composite Service Selection with QoS Constraints 6 Experiments 6.1 Experiment on Trust-Oriented Composite Service Selection 6.1.1 Comparison Using Travel Plan Composite Services Matlab 6.1.2 Comparison Using Complex Composite Services 6.2 Experiment on Trust-Oriented Composite Service Selection with QoS Constraints 7 Conclusions 文献类型： 方法揉合 研究目标： 研究方法：方法揉合 比基尼： 难点 重点 疑点 个人点评： 文章写得很一般， 文章不足之处： 作者其它文献脉络 相关重要文献 beamer_Trust-Oriented_Composite_Service_Selection_QoS_Constraints.pdf Trust-Oriented Composite Service Selection with QoS Constraints.pdf 另外三位作者有一篇大致相同文章，我只看了一大概： Trust-Oriented Composite Service Selection and Discovery.pdf 予以对比： Trust-Oriented Composite Service Selection and Discovery Lei Li, YanWang, and Ee-Peng Lim ICSOC-ServiceWave '09 Proceedings of the 7th International Joint Conference on Service-Oriented Computing, Springer-Verlag Berlin Abstract. In Service-Oriented Computing (SOC) environments, service clients interact with service providers for consuming services. From the viewpoint of service clients, the trust level of a service or a service provider is a critical issue to consider in service selection and discovery, particularly when a client is looking for a service from a large set of services or service providers. However, a service may invoke other services offered by different providers forming composite services. The complex invocations in composite services greatly increase the complexity of trust-oriented service selection and discovery. In this paper, we propose novel approaches for composite service representation, trust evaluation and trust-oriented service selection and discovery. Our experiments illustrate that compared with the existing approaches our proposed trust-oriented service selection and discovery algorithm is realistic and more efficient. 1 Introduction Service-Oriented Computing (SOC) Trust: the measure by one party on the willingness and ability of another party to act in the interest of the former party in a situation the reputation-based trust Trust: the subjective probability, that is, trust is a subjective belief Web services Composition trustworthy service selection and discovery:a very challenging some open research problems : 1. The definition of a proper graph representation of composite services including both probabilistic invocations and parallel invocations is still lacking. （ 我认为此点并不成立！） 2. subjective probability theory 3. no proper mechanism exists for evaluating the global trust of a composite service with a complex structure from the trust values of all service components 4. effective algorithms 作者工作步骤： 1）first present the service invocation graph and service invocation matrix for composite service representation 2）propose a trust evaluation method for composite services based on Bayesian inference 3）propose a service selection and discovery algorithm based on Monte Carlo method 2 Related Work QoS (quality of service) and trust previous works: 1-) Zeng: service selection linear programming 2-) Yu: QoS constraints in composite services =two optimal heuristic algorithms -- the combinatorial algorithm --the graphbased algorithm. subjective ratings: 1) Jsang 2) Wang and Singh 3) Malik 3 Service Invocation Model the outline of this section: -- present the definitions of our proposed service invocation graph -- service invocationmatrix for representing the complex structures of composite services 3.1 Composite Services and Invocation Relation Six atomic invocations: 1) Sequential Invocation 2) Parallel Invocation 3) Probabilistic Invocation 4) Circular Invocation 5) Synchronous Activation 6) Asynchronous Activation complex invocations • Probabilistic inlaid parallel invocation, denoted as Pa(S : Pr(S : A|p, B|1−p), C). • Parallel inlaid probabilistic invocation, denoted as Pr(S : Pa(S : A, B)|p, C|1 −p). • Asynchronous inlaid synchronous activation, denoted as Sy(A, As(B, C : S) : S). • Synchronous inlaid asynchronous activation, denoted as As(A, Sy(B, C : S) : S). 3.2 An Example: Travel Plan 3.3 Service Invocation Graph Definition: The service invocation graph (SIG) A service execution flow (SEF) 3.4 Service Invocation Matrix Definition: a service invocation matrix 4 Trust Evaluation in Composite Services 4.1 Trust Estimation Model 1) subjective probability theory is the right tool for dealing with trust ratings 2) Bayesian inferenceestimate the trust value 4.2 Global Trust Computation in Composite Services Goal: select the optimal one from multiple SEFs (service execution flows) in an SIG aiming at maximizing the global trust value of SEF 5 Composite Service Selection and Discovery 假设： assume that a service trust management authority stores a large volume of services with their ratings （此假设并不成立！） 5.1 Longest SEF Algorithm Dijkstra’s shortest path algorithm 5.2 Monte Carlo Method Based Algorithm (MCBA) a Monte Carlo method based algorithm (MCBA) to find the optimal SEF Monte Carlo method consists of four steps: (1) defining a domain of inputs, (2) generating inputs randomly (3) performing a computation on each input, (4) aggregating the results into the final one 6 Experiments 6.1 Comparison on Travel Plan Composite Services 6.2 Comparison on Complex Composite Services 7 Conclusions author summary: -- first propose our service invocation graph and service invocation matrix for composite service representation -- a novel trust evaluation approach based on Bayesian inference has been proposed that can aggregate the ratings from other clients and the requesting client’s prior subjective belief about the trust -- a Monte Carlo method based trust-oriented service selection and discovery algorithm has been proposed future work: -- optimize the Monte Carlo method based algorithm -- study some heuristic approaches for trust-oriented optimal service selection and discovery Conclusions 1）first propose our service invocation graph and service invocation matrix for composite service representation 2）proposed a novel trust evaluation approach based on Bayesian inference that can aggregate the ratings from other clients and the requesting client’s prior subjective belief about the trust 3）Monte Carlo method based trust-oriented service selection and discovery algorithm 个人点评： Monte Carlo method 应用尚未看懂！实验部分一般 Trust-Oriented Composite Service Selection and Discovery.pdf Finding K Optimal Social Trust Paths for the Selection of Trustworthy Service Providers in Complex Social Networks Guanfeng Liu,Yan Wang,Mehmet A. Orgun 2011 IEEE International Conference on Web Services Abstract— In a service-oriented online social network consisting of service providers and consumers as participants, a service consumer can search trustworthy service providers via the social network between them. This requires the evaluation of the trustworthiness of a service provider along a potentially very large number of social trust paths from the service consumer to the service provider. Thus, a challenging problem is how to identify K optimal social trust paths that can yield the K most trustworthy evaluation results based on service consumers’ evaluation criteria. In this paper, we first present a complex social network structure and a concept, Quality of Trust (QoT). We then model the K optimal social trust paths selection with multiple end-to-end QoT constraints as the Multiple Constrained K Optimal Paths (MCOP-K) selection problem, which is NP-Complete. For solving this challenging problem, based on Dijkstra’s shortest path algorithm and our optimization strategies, we propose a heuristic algorithm H-OSTP-K with the time complexity of O(m+Knlogn). The results of our experiments conducted on a real dataset of online social networks illustrate that H-OSTP-K outperforms existing methods in the quality of identified social trust paths. Keywords: trust, social networks, K paths selection, service provider selection I. INTRODUCTION social networks trust and social network trust path trust propagation A challenging problem: how to select those paths yielding the most trustworthy results of trust propagation based on the source participant’s trust evaluation criteria. An optimal social trust path selection model: classical MCOP selection problem, author's idea: 1) first present the structure of complex social networks 2) then introduce a concept, Quality of Trust (QoT), 3) propsed a new efficient Heuristic algorithm for the K Optimal Social Trust Path selection, called H-OSTP-K 4) conducted extensive experiments on a real online social network dataset, the Enron email dataset II. RELATED WORK A. Social Network Analysis B. Trust in Online Social Networks social relationships and recommendation roles C. Social Trust Path Selection SmallBlue: an online social network constructed for IBM staff the drawback of all existing methods: III. COMPLEX SOCIAL NETWORKS three impact factors: trust, social intimacy degree and role impact factor IV. QUALITY OF TRUST AND QOT ATTRIBUTES AGGREGATION the outline of this section: 1) first present a general concept called Quality of Trust (QoT) 2) then propose a novel K optimal social trust paths selection model with end-to-end Quality of Trust (QoT) constraints. A. Quality of Trust (QoT) Definition 1: Quality of Trust (QoT) B. QoT Attribute Aggregation 1) Trust Aggregation: 2) Social Intimacy Degree Aggregation: 3) Role Impact Factor Aggregation: C. Utility Function V. K OPTIMAL SOCIAL TRUST PATHS SELECTION the outline of this section 1) first analyze some existing algorithms for K shortest paths selection 2)then propose an efficient heuristic algorithm H-OSTP-K for the NP-Complete MCOP-K selection in complex social networks. A. Existing Algorithms The algorithms for finding K general shortest paths can be classified into two categories: (1) K general paths selection based on Dijkstra’s shortest algorithm (2) K general paths selection based on A∗ algorithm. the shortcoming of aboved methods: they are all deterministic and thus can not be used to solve the NP-Complete MCOPK selection problem B. Our Proposed H-OSTP-K author's strategy: 1) first adopt the Backward K-Search procedure 2) then adopt the Forward K-Search procedure an objective function Backward K-Search: Forward K-Search: two optimization strategies to improve the efficiency of the Forward K-Search procedure. Optimization Strategy 1: Optimization Strategy 2: VI. EXPERIMENTS A. Experiment Settings The Enron email dataset B. Experiment Results VII. CONCLUSIONS 个人点评： 没有看懂，关键是其算法。感觉作者从 social network 角度去剖析？ Finding K Optimal Social Trust Paths for the Selection of Trustworthy Service Pr.pdf A Subjective Probability Based Deductive Approach to Global Trust Evaluation in Composite Services Lei Li， Yan Wang 2011 IEEE International Conference on Web Services Abstract— In Service-Oriented Computing (SOC) environments, the trustworthiness of each service provider is critical for a service client when selecting one from a large pool of service providers. The trust value of a service provider is usually in the range of and is evaluated from the ratings given by service clients, which represent the subjective belief of service clients on the satisfaction of delivered services. So a trust value can be taken as a subjective probability, by which one party believes that another party can perform an action in a certain situation. Hence, subjective probability theory should be adopted in trust evaluation. In addition, in SOC environments, a service provider usually can invoke the services from other service providers forming a composite service. Thus, the global trust of a composite service should be evaluated based on both the subjective probability property of trust and complex invocation structures. In this paper, we first interpret the trust dependency caused by direct service invocations as conditional probability. Then, on the basis of trust dependency, we propose a SubjectivE probabiLity basEd deduCTIVE (SELECTIVE) approach to evaluate the subjective global trustworthiness of a composite service. All these processes follow subjective probability theory and keep the subjective probability property of trust in evaluations. Our experimental results demonstrate that when compared with existing approaches our proposed SELECTIVE approach can yield more reasonable results. I. INTRODUCTION service composite services trust subjective belief the callenges in SOC: to evaluate the global trust of a composite service the open problems: 1) how to adopte subjective probability theory in trust evaluation? 2) how to evaluate global trust of a composite trust? author's procedures: 1) First interpret the trust dependency caused by direct service invocations as conditional probability 2) Then propose a SubjectivE probabiLity basEd deduCTIVE (SELECTIVE) approach for subjective global trust evaluation in composite services the oraganization of this paper: 1) Section II reviews existing studies in trust evaluation, service compositionand service selection. 2) Section III briefly introduces composite services with six atomic invocations, and the probability interpretation of trust dependency. 3) Section IV presents a novel SubjectivE probabiLity basEd deduCTIVE (SELECTIVE) approach in composite services. 4) Section V presented experimentsfor further illustrating 5) Finally Section VI concludes our work. II. RELATED WORK subjective probability theory Bayesian inference QoS-aware service selection mechanisms trust-oriented service composition and selection the some drawbacks of author's previous work: trust evaluation VS reliability evaluation III. SERVICE INVOCATION AND TRUST DEPENDENCY A. Composite Service Structures Six atomic invocation relations in composite services: • Sequential Invocation: • Parallel Invocation: • Probabilistic Invocation: • Circular Invocation: • Synchronous Activation: • Asynchronous Activation: Example 1: a service invocation graph (SIG) a service execution flow (SEF) B. Rating Determination of Service Component Definition 1: C. Probability Interpretation of Trust Dependency Definition 2: trust dependency in composite services Example 2: IV. SUBJECTIVE PROBABILITY BASED DEDUCTIVE (SELECTIVE) APPROACH FOR GLOBAL TRUST EVALUATION OF COMPOSITE SERVICES Example 3: V. EXPERIMENTS the following questions: Q1: why service invocation structures should be taken into account in trust evaluation? Q2: why trust dependency caused by direct invocations should be taken into account in global trust evaluation? Q3: why the dependency caused by indirect invocations should be taken into account in trust evaluation? A. Experiment 1 on Service Invocation Structure B. Experiment 2 on Trust Dependency C. Experiment 3 on Trust-Oriented Composite Service Selection VI. CONCLUSIONS 个人点评： Yan Wang group（Macquarie University： http://web.science.mq.edu.au/~yanwang/ ）研究 Trust-oriented Web selection有自己特色，值得学习，但是 machine learning部分力度不够，我可在此改进。 另外，精读文章的参考文献值得一篇一篇研究和分析 A Subjective Probability Based Deductive Approach to Global Trust Evaluation in .pdf The Prediction of Trust Rating Based on the Quality of Services Using Fuzzy Linear Regression M. Hadi Mashinchi, Lei Li, Mehmet A. Orgun, and Yan Wang 2011 IEEE International Conference on Fuzzy Systems ( CCF C level Conference ) Abstract— With the advent of service-oriented computing, the issue of trust and Quality of Service (QoS) have become increasingly important. In service-oriented environments, when there are a few service providers providing the same service, a service client would be keen to know the trustworthiness of each service provider in the forthcoming transaction. The trust rating of a delivered service from a service provider can be predicted according to a set of advertised QoS data collected by the trust management authority. Although trust and QoS are qualitative by nature, most data sets represent trust and QoS in the ordinal form for the sake of simplicity. This paper introduces a new approach based on Fuzzy Linear Regression Analysis (FLRA) to extract qualitative information from quantitative data and so use the obtained qualitative information for better modeling of the data. For verification purposes, the proposed approach can be applied for the trust prediction in the forthcoming transaction based on a set of advertised QoS in service-oriented environments. Index Terms— Fuzzy linear regression; Trust prediction; Quality of service; I. INTRODUCTION web service selecting criteria: functionality, QoS and reputation-based trust the neglect of current work: quantization both subjective and qualitative information in the trust data set The motivations of applying FLRA for predicting trust: • Capturing the hidden fuzziness: why not machine learning • Having a transparent model: • More detailed information: This organization of thispaper: 1) Section IIreview trust management, trust evaluation and uncertainty. 2) Section IV presents our QoS based trust prediction method with fuzzy regression. 3) Section V present some experiments for illustrating how our proposed method can predict trust with QoS values. 4) Finally Section VI concludes our work. II. RELATED WORK A. Trust Evaluation in E-Commerce Environments eBay, Sporas B. Trust Evaluation in P2P Information Sharing Networks XRep, EigenTrust, PeerTrust C. Trust Evaluation in Service-Oriented Environments machine learning and soft-computing D. Uncertainty several reasons causinguncertainty : • The high complexity of the environment, • The influence of human subjective judgement in thedecision process or the involvement of human-machine interactions • Partially available information the previous work which use FLRA (Fuzzy Linear Regression Analysis): III. FUZZY REGRESSION ANALYSIS A. Classical Regression Analysis B. Fuzzy Regression Model Parameters 1) Membership Function: 2) Goodness-of-fit: 3) Fuzziness: C. Fuzzy Linear Regression Analysis (FLRA) IV. TRUST PREDICTION BASED ON FUZZY REGRESSION the objective of this paper: the application of FLRA for the prediction of trust based on a set of advertised QoS values the problem of current The critical issue: the best option: not defuzzify the data but to take the uncertainty in the data into consideration in the level of inference spread increasing problem V. EXPERIMENTS the web-services data set The settings of experiments VI. CONCLUSIONS I comment: I don't comprehensive the author's meaning. The Prediction of Trust Rating Based on the Quality of Services Using Fuzzy Line.pdf A Heuristic Algorithm for Trust-Oriented Service Provider Selection in Complex Social Networks Guanfeng Liu, Yan Wang and Mehmet A. Orgun and Ee-Peng Lim 2010 IEEE International Conference on Services Computing Abstract— In a service-oriented online social network consisting of service providers and consumers, a service consumer can search trustworthy service providers via the social network. This requires the evaluation of the trustworthiness of a service provider along a certain social trust path from the service consumer to the service provider. However, there are usually many social trust paths between participants in social networks. Thus, a challenging problem is which social trust path is the optimal one that can yield the most trustworthy evaluation result. In this paper, we first present a novel complex social network structure and a new concept, Quality of Trust (QoT). We then model the optimal social trust path selection with multiple end-to-end QoT constraints as a Multi-Constrained Optimal Path (MCOP) selection problem which is NP-Complete. For solving this challenging problem, we propose an efficient heuristic algorithm, H OSTP. The results of our experiments conducted on a large real dataset of online social networks illustrate that our proposed algorithm significantly outperforms existing approaches. I. INTRODUCTION Online social networking FilmTrust trust propagation a social trust path A challenging problem:which one is the optimal yielding the most trustworthy result of trust propagation among multiple paths? the drawbacks of previous working: neglect -- social relationships between adjacent participants -- the recommendation roles of a participant research problem: to solve the optimal social trust path selection problem in complex social networks the main contributions of this paper are summarized as follows. (1)first present the structure of complex social networks taking trust information, social relationships and recommendation roles of participants into account. In addition, we also introduce a new concept, Quality of Trust (QoT), taking the above three factors as attributes. Furthermore, we model the optimal social trust path selection problem as a Multi-Constrained Optimal Path (MCOP) selection problem. (2) propose an efficient heuristic algorithm, H-OSTP for solving the optimal social trust path selection problem (3)conducted experiments on a real online social network dataset, Enron email corpus The organization of this paper: 1) Section II presents the novel social trust path selection model in complex online social networks. 2) Section III introduces our proposed heuristic algorithm, H-OSTP. 3) Section IV presents the experimental results and analysis. 4) Finally, section V concludes this paper. II. SOCIAL TRUST PATH SELECTION IN COMPLEX SOCIAL NETWORKS the outline of this section: -- first introduce the complex social network structure --then propose a novel social trust path selection model with end-to-end Quality of Trust (QoT) constraints. A. Complex Social Networks previous work: -- Golback -- Jamali the shortcoming of current works: neglect social relationships and recommendation roles A: proposed a complex social network structure that comprises of the attributes of three impact factors of trust, social intimacy degree and role impact factor, as shown in Fig. 2. 1) Trust: 2) Social Intimacy Degree: SID 3) Role Impact Factor: RIF B. Quality of Trust (QoT) Definition 1: Quality of Trust (QoT) C. QoT Attribute Aggregation procedure: -- first need to know the aggregated value of each QoT attribute in every social trust path between a source participant and the target participant. -- The aggregated values of all the QoT attributes are then combined in a utility function defined over social trust paths, -- and then the path with the best utility value is selected as the optimal social trust path. 1) Trust Aggregation: 2) Social Intimacy Degree Aggregation: 3) Role Impact Factor Aggregation: D. Utility Function The goal of optimal social trust path selection = to select the path that satisfies multiple end-to-end QoT constraints and yields the best utility with the weights specified by the source participant. III. SOCIAL TRUST PATH SELECTION ALGORITHM the outline of this section: -- The optimal social trust path selection with multiple end-toend QoT constraints can be modelled as the classical Multi-Constrained Optimal Path (MCOP) selection problem -- first analyze some of those algorithms --then propose an efficient Heuristic algorithm for Optimal Social Trust Path selection. A. Existing Algorithms H-MCOP algorithm MCSP-K algorithm: an approximation algorithm based on H MCOP B. H-OSTP H-OSTP: an efficient heuristic algorithmfor the optimal social trust path selection with end-to-end QoT constraints in complex social networks -- first adopt the Backward Search procedure from the target -- then adopt the Forward Search procedure to search the network if a feasible solution exists an objective function in Eq. (6) to investigate whether the aggregated QoT attributes of a path can satisfy the QoT constraints Backward Search: Forward Search: IV. EXPERIMENTS the small-world characteristic the Enron email dataset A. Experiment Settings B. Performance in Social Trust Path Selection V. CONCLUSIONS A Heuristic Algorithm for Trust-Oriented Service Provider Selection in Complex S.pdf Context Based Trust Normalization in Service-Oriented Environments Lei Li and Yan Wang ATC 2010, LNCS 6407, pp. 122–138, 2010. Abstract. With the development of information technology, the issue of trust becomes more and more important. In e-commerce or service-oriented environments, when there are a few sellers or service providers providing the same product/service, the buyer or service client would like to request the trust management authority to provide trust values of sellers or service providers, which are based on the ratings reflecting the quality of previous transactions. In addition, trust is context dependent, i.e. for different context of transactions, there are different factors influencing the trust result. In this paper, we propose a fuzzy comprehensive evaluation based method for building up a projection from the trust ratings in the transaction history of a service provider to an upcoming transaction depending on the similarity between previous transactions and the upcoming one, and the familiarity between each rater and the service client of the upcoming transaction. This process is termed as context based trust normalization. After trust normalization, normalized trust ratings are used for trust evaluation, the results of which would be closely bound to the upcoming transaction. Finally, we introduce the results of our conducted experiments to illustrate how our proposed method can detect some typical risks. 1 Introduction service-oriented computing (SOC), social network and cloud computing: Trust The concept of trust varies in different disciplines. subjective probability reputation-based trust Peer-to-Peer (P2P) the following types of risks for trust management: -- Type 1 risk. -- Type 2 risk. -- Type 3 risk. trust vs. context author's work: This paper is organized as follows: 1) Section 2, we review the concept of trust, trust evaluation and subjective probability. 2) Section 3 presents our context based trust normalization method and evaluates the trust value that would be closely bound to the upcoming transaction. 3) Some experiments are presented in Section 4 for illustrating that our proposed method can detect some typical risks. 4) Finally Section 5 concludes our work. 2 Related Work 2.1 Trust Evaluation in Computer-Mediated Environments 2.2 Trust Evaluation and Subjective Probability trust vs.subjective probability Subjective probability: one of the most popular interpretations of the concept of probability -- Bayesian inference -- the rule of probability kinematics:the typical non-Bayesian inference method 3 Trust Normalization Q: trust and context dependent A: context based trust normalization 3.1 Comprehensive Evaluation Index System Q: how to find the main factors which influence context based trust normalization the most A: The criteria for developing the comprehensive evaluation index system are as follows: author's comprehensive evaluation index system: -- Transaction cost relativity: -- Transaction category similarity: -- Social relationship influence: 3.2 Fuzzy Comprehensive Evaluation Model Fuzzy comprehensive evaluation model: a synthetical application of analytical hierarchy process and fuzzy mathematics by inspecting many influencing factors. Single-level and Multi-level Fuzzy Comprehensive Evaluations. Fuzzy comprehensive evaluation: single-level and multi-level. The steps of single-level fuzzy comprehensive evaluation are as follows. The steps of multi-level fuzzy comprehensive evaluation are as follows. Establishing Affiliation Score Set. Establishing Fuzzy Affiliation Matrix. Establishing Weight Vector Establishing Affiliation Vector. Discounting Rate. 4 Experiments Epinions: a popular online reputation system 4.1 An Example of Context Based Trust Normalization 4.2 Experiment on Type 1 Risk 5 Conclusions Context Based Trust Normalization in Service-Oriented Environments.pdf Trust Transitivity in Complex Social Networks Guanfeng Liu, YanWang and Mehmet A. Orgun Proceedings of the Twenty-Fifth AAAI Conference on Artificial Intelligence Abstract In Online Social Networks (OSNs), participants can conduct rich activities, where trust is one of the most important factors for their decision making. This necessitates the evaluation of the trustworthiness between two unknown participants along the social trust paths between them based on the trust transitivity properties (i.e., if A trusts B and B trusts C, then A can trust C to some extent). In order to compute more reasonable trust value between two unknown participants, a critical and challenging problem is to make clear how and to what extent trust is transitive along a social trust path. To address this problem, we first propose a new complex social network structure that takes, besides trust, social relationships, recommendation roles and preference similarity between participants into account. These factors have significant influence on trust transitivity. We then propose a general concept, called Quality of Trust Transitivity (QoTT), that takes any factor with impact on trust transitivity as an attribute to illustrate the ability of a trust path to guarantee a certain level of quality in trust transitivity. Finally, we propose a novel Multiple QoTT Constrained Trust Transitivity (MQCTT) model. The results of our experiments demonstrate that our proposed MQCTT model follows the properties of trust and the principles illustrated in social psychology, and thus can compute more resonable trust values than existing methods that consider neither the impact of social aspects nor the properties of trust. 1 Introduction social networks a trust path: the trust transitivity property a critical and challenging problem in OSNs: how trust is transitive along a social trust path? three factors: -- the social relationships -- the recommendation roles -- the preference similarity main contributions of this paper: (1)first propose a complex social network structure that takes trust, social relationships, recommendation roles and preference similarity into account (2) Based on the properties of trust illustrated in social psychology, we then propose a new Multiple QoTT Constrained Trust Transitivity (MQCTT) model. (3)conducted experiments on several subnetworks extracted from the Enron email dataset 2 RelatedWork three categories according to the types of trust transitivity strateg: 1-) multiplication strategy 2-) averaging strategy 3-) confidence-based strategy some drawbacks in the above three categories of trust transitivity models: 3 A Complex Social Network a new complex social network structure, as depicted in Fig. 1. It contains the attributes of four impact factors, i.e., trust, social intimacy degree, role impact factor and preference similarity. 3.1 Trust 3.2 Social Intimacy Degree The following principle in social psychology illustrates the impact of the social relationships between participants on trust. Principle 1. 3.3 Role Impact Factor 3.4 Preference Similarity 4 Trust Properties and the Quality of Trust Transitivity the outline of this section: -- 4.1 The properties of Trust 4.2 Quality of Trust Transitivity (QoTT) Definition 4. Quality of Trust Transitivity (QoTT) 4.3 QoTT Constraint 4.4 The Aggregation Method for QoTT Attributes 4.4.1 Trust Aggregation 4.4.2 Social Intimacy Degree Aggregation 5 Multiple QoTT Constrained Trust Transitivity (MQCTT) Model Step 1 (average trust decay speed): Step 2 (intersection angle θ): Step 3 (the scope of θ): Step 4 (logistic function): Step 5 (computing θ value): 6 Experiments 6.1 Experiment Settings I comment: Trust Transitivity in Complex Social Networks.pdf Subjective Trust Inference in Composite Services Lei Li and YanWang Proceedings of the Twenty-Fourth AAAI Conference on Artificial Intelligence (AAAI-10) Abstract In Service-Oriented Computing (SOC) environments, the trustworthiness of each service is critical for a service client when selecting one from a large pool of services. The trust value of a service is usually in the range of and is evaluated from the ratings given by service clients, which represent the subjective belief of these service clients on the satisfaction of delivered services. So a trust value can be taken as the subjective probability, with which one party believes that another party can perform an action in a certain situation. Hence, subjective probability theory should be adopted in trust evaluation. In addition, in SOC environments, service usually invokes other services offered by different ervice providers forming a composite service. hus, the global trust of a composite service should be valuated based on complex invocation structures. In this paper, firstly, based on Bayesian inference, we propose a novel method to evaluate the subjective trustworthiness of a service component from a series of ratings given by service clients. Secondly, we interpret the trust dependency caused by service invocations as conditional probability, which is evaluated based on the subjective trust values of service components. Furthermore, we propose a joint subjective probability method to evaluate the subjective global trust of a composite service on the basis of trust dependency. Finally, we introduce the results of our conducted experiments to illustrate the properties of our proposed subjective global trust inference method. 1 Introduction Service-Oriented Computing (SOC) a service: an autonomous, platform-independent computational entity, which can be described, published, discovered and dynamically assembled for developing massively distributed systems trust:the measure taken by one party on the willingness and ability of another party to act in the interest of the former party in a certain situation open problems: author's work: -- first propose a Bayesian inference based subjective trust estimation method for service components. --interpret the trust dependency caused by service invocations as conditional probability, which can be evaluated based on the trust values of service components. --propose a joint subjective probability method to evaluate the subjective global trust of a composite service on the basis of trust dependency. the organization of this paper: 1)Section 2 reviews existing studies in trust management, service selection and service composition. 2) Section 3 briefly introduces composite services with six atomic invocations. 3) Section 4 presents our novel joint subjective probability method in composite services. 4) Experiments are presented in Section 5 for further illustrating the properties of our proposed method. 5) Finally Section 6 concludes our work. 2 RelatedWork the drawbacks of previous work: -- omit parallel invocation the focus ofthis paper: a proper subjective global trust inference methodfor trust-oriented composite service selection and discovery 3 Service Invocation Model A composite service Six atomic invocationsin composite services are introduced below and depicted in Fig. 1 Example 1: a service invocation graph (SIG) in Fig.2. a service execution flow (SEF), which is the subgraph of SIG. 4 Subjective Trust Inference subjective probability theory the outline of this section: --Section 4.1 presents a novel method , based on Bayesian inference, evaluates the subjective trust of service components -- Section 4.2interprets the trust dependency caused by service invocations as conditional probability -- Section 4.3propose a joint subjective probability method that evaluates the subjective global trust value of an SEF from the trust values and trust dependency of all service components. 4.1 Trust Estimation of Service Components Rating Space and Trust Space Definition 1 The rating space Definition 2 The trust space Bayesian Inference Certainty, Expected Positiveness and Expected Negativeness Definition 3 The certainty Definition 4 The expected positiveness From Rating Space to Trust Space 4.2 Probability Interpretation of Trust Dependency 4.3 Joint Subjective Probability Method 5 Experiments and Analysis 5.1 Important Properties in Trust Estimation 5.2 Experiment on Subjective Trust Inference 6 Conclusions I comment: Subjective Trust Inference in Composite Services.pdf mynote: Subjective Trust Inference in Composite Services.pdf The study of trust vector based trust rating aggregation in service-oriented environments Lei Li · Yan Wang WorldWide Web journal (Springer), 2011 Abstract In most existing studies on trust evaluation, a single trust value is aggregated from the ratings given to previous services of a service provider, to indicate his/her current trust level. Such a mechanism is useful but may not be able to depict the trust features of a service provider well under certain circumstances. Alternatively, a complete set of trust ratings can be transferred to a service client for local trust evaluation. However, this incurs a big overhead in communication, since the rating dataset is usually in large scale covering a long service history. The third option is to generate a small set of data that should represent well the large set of trust ratings of a long time period. In the literature, a trust vector approach has been proposed, with which a trust vector of three values resulting from a computed regression line can represent a set of ratings distributed within a time interval (e.g., a week or a month, etc.). However, the computed trust vector can represent the set of ratings well only if these ratings imply consistent trust trend changes and are all very close to the obtained regression line. In a more general case with trust ratings for a long service history, multiple time intervals have to be determined, within each of which a trust vector can be obtained and can represent well all the corresponding ratings. Hence, a small set of data can represent well a large set of trust ratings with well preserved trust features. This is significant for large-scale trust rating transmission, trust evaluation and trust management. In this paper, we propose one greedy and two optimal multiple time interval (MTI) analysis algorithms. We also have studied the properties of our proposed algorithms analytically and empirically. These studies can illustrate that our algorithms can return a small set of MTI to represent a large set of trust ratings and preserve well the trust features. Keywords reputation-based trust · trust rating aggregation · trust vector · multiple time intervals 1 Introduction Service-Oriented Computing (SOC) a trust vector with three values: -- final trust level (FTL) -- service trust trend (STT) -- service performance consistency level (SPCL) multiple time interval (MTI) analysis the contributions of this paper can be briefly summarized as follows: 1-. The bisection-based boundary excluded greedy MTI algorithm consumes much less CPU time than any of the other four MTI algorithms. 2-. The boundary excluded optimal MTI algorithm can return the minimal set of boundary excluded MTI. 3-. The boundary mixed optimal MTI algorithm returns a minimal set of boundary mixed MTI. This set is no larger than the set returned by any of the other four MTI algorithms. 4-. With any of our proposed algorithms, a small set of data can represent well a large set of trust ratings with well preserved trust features. 2 Related work 2.1 Trust aggregation approaches in online environments 2.1.1 Trust evaluation in e-commerce environments eBay Sporas system Histos system fuzzy logic trust model 2.1.2 Trust evaluation in P2P information sharing networks XRep EigenTrust PeerTrust two main features of PeerTrust -- voting reputation system PowerTrust 2.1.3 Trust evaluation in service-oriented environments 2.1.4 Trust evaluation in multi-agent systems TRAVOS system 2.2 Existing trust vector approaches 3 Trust vector evaluation the outline of this section: 3.1 Final trust level (FTL) evaluation 3.2 Service trust trend (STT) evaluation 3.3 Service performance consistency level (SPCL) evaluation 4 Multiple time interval (MTI) analysis 4.1 Boundaries of MTI 4.2 Bisection-based boundary excluded greedy MTI algorithm 4.4 Boundary mixed optimal MTI algorithm 5 Experiments 6 Conclusions I comment: I don't find the originality of this paper The study of trust vector based trust rating aggregation in service-oriented env.pdf
Y.S. Sun , B.W. Li. A spectral collocation method for transient conduction-radiation heat transfer. Journal of Thermophysics and Heat Transfer (to be published). download Abstract: Chebyshev spectral collocation method is developed to solve transient coupled conduction and radiation heat transfer problems. For both radiative transfer equation (RTE) and energy equation, the spatial domain is discretized by Chebyshev collocation spectral method. The angular domain is discretized by discrete ordinates method for RTE. The formulations and implementation of Chebyshev collocation spectral-discrete ordinates method (SP-DOM) reveal its high efficiency. Due to the exponential convergence of spectral methods, a very high accuracy can be obtained even using small number of node for present problems. Numerical results in one dimensional planar and two dimensional rectangular geometries by SP-DOM are compared with those available data in references. Effects of various parameters, like the scattering albedo, the conduction-radiation parameter and the optical thickness are studied for absorbing, emitting and scattering medium. The results show that the SP-DOM can provide good accuracy and efficiency for solving transient conduction and radiation heat transfer problems.
Workshop on Tools and Methods for Trade and Trade Policy Analysis Geneva, 11-15 September, 2006 以下是主页和ftp，从workshop主页进去有分类信息，方便查找。 http://vi.unctad.org/tda/ http://vi.unctad.org/tda/presentations/13%20September/Vanzetti/ 【15 September】 CGE-VI-Sept06.ppt 24-Nov-2006 09:53 576K Communication with Policy Makers II VM.ppt 24-Nov-2006 09:53 147K 【14 September】 Exercise 2_gravity-rev.doc Gravity UNCATD 2006.ppt Modelling Methods for Trade Policy: Gravity Models Workshop TPA - Trade potentials.ppt Using gravity models to calculate trade potentials for developing countries Gravity Model http://vi.unctad.org/tda/gravity.html ? Gravity for Beginners http://vi.unctad.org/tda/background/Introduction%20to%20Gravity%20Models/gravity.pdf ? Gravity with Gravitas: A Solution to the Border Puzzle http://vi.unctad.org/tda/papers/Gravity%20Models_Roberta_Jean/Anderson_van%20Wincoop%20(2003)%20Gravity%20with%20gravitas%20-%20a%20solution%20to%20the%20border%20puzzle.pdf ? Do Free Trade Agreements Actually Increase Members International Trade? http://vi.unctad.org/tda/papers/Gravity%20Models_Roberta_Jean/Baier_Bergstrand_2005.pdf ? Trading Partners and Trading Volumes http://vi.unctad.org/tda/papers/Gravity%20Models_Roberta_Jean/HMR_2006.pdf ? Do We Really Know that the WTO Increases Trade? http://vi.unctad.org/tda/papers/Gravity%20Models_Roberta_Jean/Rose_WTO_AER%20in%20NBERw9273%5B1%5D.pdf ? Why Trade Costs Matter? http://vi.unctad.org/tda/papers/Gravity%20Models_Roberta_Jean/Why%20trade%20costs%20matter_ArtNet%2004_06%5B1%5D.pdf 【13 September】 Partial Equilibrium Model http://vi.unctad.org/tda/partequilibrium.html AR_beef.XLS Non-linear Armington model - EU Beef Imports ATPSM.ppt Assessing the agricultural negotiations with ATPSM GSIM_beef.XLS Global Simulation Analysis of Industry Level Trade Policy - 2003 GSIMpaper.pdf PE.ppt Do-it-yourself partial equilibrium modelling Perfect_beef.xls Perfect substitutes model - EU Beef linear.xls Four region non-spatial model data_beef.XLS ===================================== The Toolbox Perfect (single market) Imperfect substitutes (Armington) Multi-region perfect Global Armington (GSIM) Global perfect (ATPSM) ==================================== Some model soft can be downloaded from: www.interceonomics.com 【12 September】 AMAD presentation3.ppt 24-Nov-2006 09:53 177K MM Trade Policy wkshop 12Sept06.ppt 24-Nov-2006 09:53 3.7M WITS TRaining.ppt 24-Nov-2006 09:53 5.8M WITS_TRAINS_Overview_All.ppt 24-Nov-2006 09:53 455K 【11 September】 Choosing methodology v1.ppt 24-Nov-2006 09:52 103K Vi TDA workshop Sept.06.ppt 24-Nov-2006 09:52 106K Vi Website.ppt 24-Nov-2006 09:53 1.1M The UNCTAD Trade Policy Simulation Model: A note on the methodology, data and uses http://vi.unctad.org/tda/background/Partial%20Equilibrium%20Models%20-%20SMART/SMART.pdf
The following are some comparisons between the FMM and WCM: (1) A large part of the CPU time of the FMM is spent on the iteration. However, in WCM, iteration is much fast since the matrix is computed and saved in memory. (2) In FMM, the M2L transforms must be optimaized since it is re-computed in each iteration. In wavelet method, M2L is used only once (in matrix computation). Thus we conclude that the WCM is more suitable for problem needing relatively large number of iterations to converge, while the FMM is efficient when the number of iterations is small, e.g., less than 50.
来自于princeton CS的一条科技新闻： Pai and colleagues' HashCache technology named one of Technology Review's Top 10 Emerging Technologies for 2009 February 24, 2009 Vivek Pai's new method for storing Web content could make Internet access more affordable around the world. 项目目标与宏观技术理论介绍 http://www.technologyreview.com/web/22119/ 有关HashCache技术理论的细节请见论文 'HashCache: Cache Storage for the Next Billion' Vivek Pai的主页 视频资料
论文名 : Pi-calculus based assembly mechanism of UML state diagram and Validation of model refinement Abstract: UML provides a graphical method to model object-oriented system. However, UML is a meta-model which has only static semantics and without dynamic semantics. From the perspective of assembly mechanism, we proposed six kinds of UML state diagram's assembly mechanisms, and gave the mapping rules between assembly mechan1ism and picalculus. Finally we proved that it is practical to validate model refinement with above theory in two different ways ---- experiment and theory deduction. The theory deduction coincides with the experiment results. Furthermore, the mobile assembly and interrupt assembly we proposed supplement for the insufficient description ability of UML. 发表会议：2009 International Conference on Electronic Computer Technology(ICECT 2009, EI检索) 发表日期： 2008 年 11 月
新安装的fedora9存在bug，不能开启im-method，所以要先修复这个bug 方法如下： ［1］yum update scim -y ［2］yum install scim-lang-chinese -y ［3］修改配置文件vim /etc/X11/xinit/xinitrc.d/50-xinput.sh 找到下面的语句 _language_list=as bn gu hi ja kn ko ml mr ne or pa si ta te th ur vi zh en 在后面添加蓝色的部分。 ［4］重启fedora，就可以使用scim了，根据自己的爱好和需要配置快捷键就可以了。 接下来就是设置热键切换。 按照以下顺序，系统－首选项－个人－输入法，把启用输入法特性勾上，然后点击下面的首选输入法，在出来的界面中，依次进入前端－全局设置，在全局设置里， 首先选择键盘布局为英国（美国），然后点击下面的开关键后面的（.)，进入切换热键的设置，为了避免跟系统中其他热键有冲突，建议选择 Ctrl+space.在默认的选择里没有Ctrl+space这样的组合，这需要自己来设置。点击键码框后面的（..)，然后弹出一个捕捉热键的小程 序，这时同时按下Ctrl+space，程序会自动记录这样的组合而后自动关闭，设置好组合后，再点添加，然后一路确定。
标签: method
