In this paper, a network switch performance anomaly detection method of the instrumentation and control (I&C) systems in nuclear power plants (NPP) based on network calculus is proposed. In the Ethernet-based packet switching I&C system network, the delay of a network switch is an important indicator of network performance. With the development of small modular reactor (SMR) technology, the scale of the I&C systems in NPPs has increased. The I&C systems of SMRs are often constructed in batches with a modular architecture, which imposes higher requirements for the extensibility of the network architecture and network performance. Traditional network performance analysis uses the queuing theory based on the statistic method and the stochastic process to analyze the average performance of the network, instead of analyzing the deterministic boundary of system performance. In this paper, anomaly detection methods based on network calculus are proposed for network switches in the NPP I&C system by detecting rate-latency performance, delay, and data

anomalies. Network calculus is a deterministic queuing theory based on nonlinear algebra. It takes the data flow as the research object, obtaining the performance bound of network nodes through the convolution and deconvolution of the min-plus algebra. The MATLAB simulation experiments are conducted and verify the effectiveness of the anomaly detection methods.

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Active portfolio managers need to have the ability to construct a portfolio which outperforms a market, i.e., a benchmark, using their prediction ability. Many active portfolio managers, however, faced the problem that the exante possibility was different from the ex-post delivery for an active portfolio. The gap comes from the ignorance of the trader's role by portfolio managers. We focused on the role of portfolio managers and traders in order to fill the gap. We propose a method for finding a series of portfolios, each of which can be applicable for practical situations. Our method consists of two steps where the first step is for active portfolio managers, and the second one for traders. This is a realization of the separation of the role of active portfolio managers and traders, strategically.

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The present paper studies a discrete-time storage process with discrete states. This model has the inflow which is defined as independent random variables with a common negative binomial distribution and has the certain outflow discipline. Reversibility and quasi-reversibility for the process are investigated and the reversible measure is given. And thus, under a certain condition, it is shown that the process has time-reversibility with the stationary distribution constructed by the reversible measure. Also dynamic reversibility for the process is shown. As an application of the present results we consider an inventory model with a for orders from substations. And the relationship between the Lindley process and this model is discussed. Moreover,we deal with tandem storage models of an open or a closed network whose each node has the outflow discipline of the certain form. For each model, the invariant measure of the product form is obtained.

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Emerging data-intensive services in distribution grid impose requirements of high-concurrency access for massive internet of things (IoT) devices. However, the lack of effective high-concurrency access management results in severe performance degradation. To address this challenge, we propose a cloud-edge-device collaborative high-concurrency access management algorithm based on multi-timescale joint optimization of channel pre-allocation and load balancing degree. We formulate an optimization problem to minimize the weighted sum of edge-cloud load balancing degree and queuing delay under the constraint of access success rate. The problem is decomposed into a large-timescale channel pre-allocation subproblem solved by the device-edge collaborative access priority scoring mechanism, and a small-timescale data access control subproblem solved by the discounted empirical matching mechanism (DEM) with the perception of high-concurrency number and queue

. Particularly, information uncertainty caused by externalities is tackled by exploiting discounted empirical performance which accurately captures the performance influence of historical time points on present preference value. Simulation results demonstrate the effectiveness of the proposed algorithm in reducing edge-cloud load balancing degree and queuing delay.

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With growing avionics applications, the transmission of avionics data flows has been increasing in real-time avionics networks of aircraft. An Avionics Full DupleX switched Ethernet (AFDX), standardized as ARINC 664, is chosen as the backbone network for distributed real-time avionics systems as it offers high throughput and does not require global clock synchronization. Estimating the end-to-end transmission delay to validate the network performance is essential for both certification and industrial research. Because of the various waiting times caused by the

(i.e., the pending packets in the output port of the visited switch), it is necessary and reasonable to compute the worst-case end-to-end transmission delay to validate network performance. Several approaches have been designed to compute the upper boundaries of end-to-end transmission delays, such as the Network Calculus approach and the Trajectory approach. In this paper, we focus on a new approach, Forward end-to-end delay Analysis (FA). This approach iteratively estimates the maximum (i.e., number of pending packets) in each switch visited along the transmission path, so that the worst-case end-to-end transmission delay can be computed and the network performance evaluated. We also present the termination condition for this iterative estimation. The experiments demonstrate that this approach achieves a more accurate evaluation of transmission performance than the Network Calculus approach. A comparison with the exact upper boundaries obtained using the Model Checking approach shows the pessimism (i.e., overestimation) in FA. This paper analyses the reasons for that pessimism, and proposes future research.

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Admission control is a procedure to guarantee a given level of Quality of Service (QoS) by accepting or rejecting arrival connection requests. There are many studies on or loss rate evaluation formulas for admission control at a single node. However, there are few studies on end-to-end evaluation formulas suitable for admission control. In a previous paper, the authors proposed a new stochastic network calculus for many flows using an approach taken from large deviations techniques and obtained asymptotic end-to-end evaluation formulas for output burstiness and . In this paper, we apply this stochastic network calculus to a heterogeneous tandem network with many forwarding flows and cross traffic flows constrained by leaky buckets, and obtain a simple evaluation formula for the end-to-end . In this formula, the end-to-end can be evaluated by the traffic load at the bottle neck node. This result leads us to a natural extension of the evaluation formula for a single node.

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Power line communication (PLC) provides a flexible-access, wide-distribution, and low-cost communication solution for distribution network services. However, the PLC self-organizing networking in distribution network faces several challenges such as diversified data transmission requirements guarantee, the contradiction between long-term constraints and short-term optimization, and the uncertainty of global information. To address these challenges, we propose a backpressure learning-based data transmission reliability-aware self-organizing networking algorithm to minimize the weighted sum of node data backlogs under the long-term transmission reliability constraint. Specifically, the minimization problem is transformed by the Lyapunov optimization and backpressure algorithm. Finally, we propose a backpressure and data transmission reliability-aware state-action-reward-state-action (SARSA)-based self-organizing networking strategy to realize the PLC networking optimization. Simulation results demonstrate that the proposed algorithm has superior performances of data backlogs and transmission reliability.

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DOCSIS is the defacto industry standard for cable internet to the home. In this letter, we examine the delay characteristics of commercially deployed DOCSIS networks. We focus on four mechanisms of the DOCSIS MAC operation and develop a computationally simple simulator to reproduce the phenomena produced by these mechanisms. In reproducing these phenomena using our simulator, we demonstrate that the simulator properly encapsulates the core mechanisms of DOCSIS and effectively simulates the delay of packets.

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Fast identification is an urgent demand for modern RFID systems. In this paper, we propose a novel algorithm, access probability adjustment based fine-grained Q-algorithm (APAFQ), to enhance the efficiency of RFID identification with low computation overhead. Specifically, instead of estimation accuracy, the target of most proposed anti-collision algorithms, the APAFQ scheme is driven by updating Q value with two different weights, slot by slot. To achieve higher identification efficiency, the reader adopts fine-grained access probability during the identification process. Moreover, based on the responses from tags, APAFQ adjusts the access probability adaptively. Simulations show the superiority of APAFQ over existing Aloha-based algorithms.

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More and more factories operate on a just-in-time basis. In order to shorten planning cycles and minimize inventory levels in the value chain, transportation plays a critical role in the supply chain process. Collaborative Transportation Management (CTM) is based on the interaction and collaboration between trading partners and carriers on the supply chain, in order to avoid the inefficiency of physical distribution and accomplish the objective of improving the efficiency of supply chain management. This paper proposes a concept of CTM and a system framework for evaluating the benefits of CTM. Based on the beer game, we develop a beer game model of supply chain with CTM, and present the different simulation scenarios: (1) Constrained transportation capacity in beer game with CTM; (2) Constrained transportation capacity in beer game without CTM; and (3) Unconstrained transportation capacity in beer game without CTM. The manufacturers, distributors and carriers in the supply chain are considered as the partners of CTM. Results of the simulation reveal that CTM can significantly reduce the total supply chain costs, including inventory costs and costs, and improve transportation capacity utilization.

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In communication networks, congestion control, routing, and multiple access schemes for scheduling transmissions are typically regulated by distributed algorithms. Engineers designed these algorithms using clever heuristics that they refined in the light of simulation results and experiments. Over the last two decades, a deeper understanding of these algorithms emerged through the work of researchers. This understanding has a real potential for improving the design of protocols for data centers, cloud computing, and even wireless networks. Since protocols tend to be standardized by engineers, it is important that they become familiar with the insights that emerged in research. We hope that this paper might appeal to practitioners and make the research results intuitive and useful. The methods that the paper describes may be useful for many other resource allocation problems such as in call centers, manufacturing lines, hospitals and the service industry.

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Purpose : The aim of the eye care project is to clear the of cataract blindness for the people of Gaur and its surrounding districts in southeast Nepal. The purpose of this study is to analyze the progress of this eye care project.
Methods : In mid 1997, the Nepal Netra Jyoti Sangh (NNJS), the national society for comprehensive eye care in Nepal, with financial support from the Association for Ophthalmic Cooperation to Asia (AOCA) and the 24 Hour Television (24HTV) Charity Committee established an eye hospital in the district headquarters of Gaur under the name of Narayani Eye Care Project (NECP). The hospital provides surgery, an outpatient department (OPD) and emergency services. We analyzed the number of patients, the number of surgeries and the profile of patients.
Results : The hospital was found to be providing services with modern equipment and instruments and the number of patients frequenting it had increased in accordance with the improved services. From mid 1997 until the end of 2002, the hospital provided services to a total of 122, 093 patients and performed 6, 143 major surgeries and 541 minor surgeries.
Conclusions : It has been possible to conduct sight restorations of poor and blind individuals in this region at the Gaur eye hospital with the support of the NECP.

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The endurance time of smartphone still suffer from the limited battery capacity, and smartphone apps will increase the burden of the battery if they download large data over slow network. So how to manage the download tasks is an important work. To this end we propose a smartphone download strategy with low energy consumption which called CLSA (Concentrated Download and Low Power and Stable Link Selection Algorithm). The CLSA is intended to reduce the overhead of large data downloads by appropriate delay for the smartphone, and it based on three major factors: the current network situation, the length of download requests' queue and the local information of smartphone. We evaluate the CLSA using a music player implementation on ZTE V880 smartphone running the Android operation system, and compare it with the other two general download strategies, Minimum Delay and WiFi Only. Experiments show that our download algorithm can achieve a better trade-off between energy and delay than the other two.

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This study aims to analyse Indonesian housing policies and practices at the local level, focusing on the Metropolitan Area of West Java, Indonesia. Secondary data was obtained from current Indonesian basic regulations in Housing Affairs and Regional Administration Laws, while primary data was collected from interviews with bureaucratic actors from central, provincial, and city/regency governments. Data is processed through qualitative content analysis. The discussion of housing provision for low-income communities refers to self-help and public housing modes. The result shows that the local government's role in self-help housing provision is mostly in supporting quality improvement, which is less effective since the quality was not well-maintained. Local government also has limited authority in public housing provision, raising policy debates and polemics on its field implementation. This study recommends a housing delivery system instead of divisions in authorities. The governments can develop various public-private partnership schemes to support public housing provision. In addition, a clear vertical housing career path is essential to encourage low-income people's acceptance of urban vertical living.

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It is well known that SCM has an effect that reduces the extra stock and the cost of system, but how it can make all enterprises achieve the maximal profit is becoming the new problem in the institutional view. First, the two parallel SCM models are identified and formulated on the queueing base of Make-or-Buy and Supplier-Retailers types. Next, the problem of ellipse hypothesis in SCM is numerically discussed in the integral balancing view. Integral balancing means that both economics (profit) and reliability (workload) hold in autonomous balancing by cycle-time sharing. In particular, a feature map in a balance matrix is suggested for a win-win strategy, and is compared to the ellipse theory in the serial SCM type.

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A production planning model for multi-product facilities is analyzed, in which known demands must be satisfied. In the model, in every production period each facility produces a certain number of items each taking a fixed part of the production amount. Concave production costs dependent upon the production in different facilities and piecewise concave inventory costs are considered. Both the nonbacklog and permitted cases are considered. The structure of an optimal solution is characterized and then used, illustratively in a simple dynamic programming algorithm for nonbacklog single-facility problems.

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Fair queueing is a service scheduling discipline to pursue the fairness among users in packet communication networks. Many fair queueing algorithms, however, have problems of computational overhead since the central scheduler has to maintain a certain performance counter for each flow of user packets based on the global virtual time. Moreover, they are not suitable for wireless networks with high probability of input channel errors due to the lack or complexity in the compensation mechanism for the recovery from the error state. In this paper, we propose a new, computationally efficient, distributed fair queueing scheme, which we call Channel-Aware Throughput Fair Queueing (CATFQ), that is applicable to both wired and wireless packet networks. In our CATFQ scheme, each flow is equipped with a counter that measures the weighted throughput achievement while it has a of packets. At the end of every service to a packet, the scheduler simply selects a flow with the minimum counter value as the one from which a packet is served next. We show that the difference between any two throughput counters is bounded. Our scheme significantly reduces the scheduler's computational overhead and guarantees fair throughput for all flows. For wireless networks with error-prone channels, the service chance lost in bad channel condition is compensated quickly as the channel recovers. Our scheme suppresses the service for leading flows, brings short-term fairness for flows without channel errors, and achieves long-term fairness for all flows. These merits are verified by simulation.

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The rapid urbanization of Greater Jakarta has resulted in the urban expansion of its peripheral cities, one of which is Tangerang city, which is considered the most developed peripheral city compared to the others. While the development of housing including highrise apartments and commercial centers is spreading all over Tangerang city, as a suburban area, the development of infrastructure is still insufficient, especially in the case of the neighborhood facilities. As an effect of rapid urbanization, the housing as well as the quantity of inadequate housing has increased, and many slum settlements have emerged. The development of subsidized apartments was chosen by the planning officials to mitigate the housing by providing housing with better facilities and building features. One of the important factors to be considered to understand people’s decisions to move to better housing was place-attachment. This study investigates how far place-attachment affects the slum dwellers’ willingness to move to Rusunawa by using quantitative methods in the form of descriptive analysis and in-depth interviews. The results show that, to a certain degree, place-attachment plays an important role in residents’ willingness to move.

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