Modeling and control of bulk material flow on the electromagnetic vibratory feeder

© 2016 Taylor and Francis Group LLC. This paper presents the results of modeling, simulation and experimental research of the bulk material flow on the electromagnetic vibratory feeder (EVF). The model of the EVF was implemented in Simulink/Matlab and verified in the experimental research. It has been experimentally confirmed that the bulk material flow rate has its maximal value as far as excitation frequency is equal to the EVF mechanical resonant frequency. For certain bulk material flow rate, average value of excitation coil current of EVF has minimal value when named frequencies are equal. In addition to modeling of the EVF, the main contribution of this paper is implementation of flow control algorithm of bulk material on EVF, experimental verification of the adopted model and defines parameters that enable the selection of energy-efficient operating point of the EVF

Towards a Formal Framework for Computational Trust

We define a mathematical measure for the quantitative comparison of probabilistic computational trust systems, and use it to compare a well-known class of algorithms based on the so-called beta model. The main novelty is that our approach is formal, rather than based on experimental simulation

Online Reputation Systems in Web 2.0 Era

Web 2.0 has transformed how reputation systems are designed and used by the Web. Based on a thorough review of the existing online reputation systems and their challenges in use, this paper studied a case of Amazon’s reputation system for the impacts of Web 2.0. Through our case study, several distinguished features of new generation reputation systems are noted including multimedia feedbacks, reviewer centered, folksonomy (use of tag), community contribution, comprehensive reputation, dynamic and interactive system etc.. These new developments promise a path that move towards a trustworthy and reliable online reputation system in the Web 2.0 era

A Buck-Boost Converter Modified to Utilize 600V GaN Power Devices in a PV Application Requiring 1200V Devices

This paper presents a buck-boost converter which is modified to utilize new 600 V gallium nitride (GaN) power semiconductor devices in an application requiring 1200 V devices. The presented buck-boost converter is used as a part of a dc/dc stage in an all-GaN photovoltaic (PV) inverter and it provides a negative voltage for the 3-level neutral-point-clamped (NPC) PWM inverter which is connected to the utility grid. Since in this application the transistor and the diode of the buck-boost converter need to block the sum of the PV string voltage (which is normally in the range from 150 to 350 V) and the dc bus voltage (which is in the order of 400 V), the 1200 V devices or series connection of 600 V devices need to be employed. Currently, 1200 V GaN power semiconductor devices are not commercially available. Therefore, the standard buck-boost converter is modified to enable the use of 600 V GaN devices in this particular application. Based on the proposed converter topology, a PSpice simulation model and a 600 W converter prototype were developed. Both simulation and experimental results show successful operation of the converter

Agents and Peer-to-Peer Computing5th International Workshop, AP2PC 2006, Hakodate, Japan, May 9, 2006, Revised and Invited Papers

Peer-to-peer (P2P) computing has attracted significant media attention, initiallyspurred by the popularity of file-sharing systems such as Napster, Gnutella, andMorpheus.More recently systems like BitTorrent and eDonkey have continued tosustain that attention. New techniques such as distributed hash-tables (DHTs),semantic routing, and Plaxton Meshes are being combined with traditional conceptssuch as Hypercubes, Trust Metrics, and caching techniques to pool togetherthe untapped computing power at the “edges” of the Internet. These newtechniques and possibilities have generated a lot of interest in many industrialorganizations, and have resulted in the creation of a P2P working group on standardizationin this area (http://www.irtf.org/charter?gtype=rg&group=p2prg).In P2P computing, peers and services forego central coordination and dynamicallyorganize themselves to support knowledge sharing and collaboration,in both cooperative and non-cooperative environments. The success of P2P systemsstrongly depends on a number of factors. First, the ability to ensure equitabledistribution of content and services. Economic and business models whichrely on incentive mechanisms to supply contributions to the system are beingdeveloped, along with methods for controlling the “free riding” issue. Second,the ability to enforce provision of trusted services. Reputation-based P2P trustmanagement models are becoming a focus of the research community as a viablesolution. The trust models must balance both constraints imposed by theenvironment (e.g., scalability) and the unique properties of trust as a social andpsychological phenomenon. Recently, we are also witnessing a move of the P2Pparadigm to embrace mobile computing in an attempt to achieve even higherubiquitousness. The possibility of services related to physical location and therelation with agents in physical proximity could introduce new opportunities andalso new technical challenges.Although researchers working on distributed computing, multi-agent systems,databases, and networks have been using similar concepts for a long time, it isonly fairly recently that papers motivated by the current P2P paradigm havestarted appearing in high-quality conferences and workshops. Research in agentsystems in particular appears to be most relevant because, since their inception,multiagent systems have always been thought of as collections of peers.The multiagent paradigm can thus be superimposed on the P2P architecture,where agents embody the description of the task environments, the decisionsupportcapabilities, the collective behavior, and the interaction protocols ofeach peer. The emphasis in this context on decentralization, user autonomy, dynamicgrowth, and other advantages of P2P also leads to significant potentialproblems. Most prominent among these problems are coordination: the abilityof an agent to make decisions on its own actions in the context of activitiesof other agents; and scalability: the value of the P2P systems lies in how well they scale along several dimensions, including complexity, heterogeneity of peers,robustness, traffic redistribution, and so forth. It is important to scale up coordinationstrategies along multiple dimensions to enhance their tractability andviability, and thereby to widen potential application domains. These two problemsare common to many large-scale applications.Without coordination, agentsmay be wasting their efforts, squandering resources, and failing to achieve theirobjectives in situations requiring collective effort.This workshop series brings together researchers working on agent systems andP2P computing with the intention of strengthening this connection. Researchersfrom other related areas such as distributed systems, networks, and databasesystems are also welcome (and, in our opinion, have a lot to contribute). Weseek high-quality and original contributions on the general theme of “Agentsand P2P Computing.

Three-Level Delta Modulation for Laplacian Source Coding

This paper proposes a novel solution for coding of time varying signals with Laplacian distribution, which is based on delta modulation and three-level quantization. It upgrades the conventional scheme by introducing the quantizer with variable length code. Forward adaptive scheme is used, where the adaptation to the signal variance is performed on frame-by-frame basis. We employ configurations with simple fixed first-order predictor and switched first-order predictor utilizing correlation. Furthermore, we propose different methods for optimizing predictor coefficients. The configurations are tested on speech signal and compared to an adaptive two-level and four-level delta modulation, showing that proposed three-level delta modulation offers performance comparable to a four-level baseline with significant savings in bit rate

Three-Level Delta Modulation with Second-Order Prediction for Gaussian Source Coding

An adaptive three-level delta modulation with a switched second-order linear prediction is proposed in this paper, intended for encoding the time-varying signals modeled by Gaussian distribution. The input signal is processed frame-by-frame, and the adaptation of the quantizer is performed at the frame level. The signal at the output of quantizer is further processed using variable length encoder to decrease the bit rate. The performance is tested in speech coding, showing that the proposed algorithm provides much wider dynamic range and attains higher Signal to Noise Ratio with respect to the baselines, including CFDM, CVSDM and 2-bit Adaptive Delta Modulation