The Experts below are selected from a list of 198 Experts worldwide ranked by ideXlab platform
Yi-kuei Lin - One of the best experts on this subject based on the ideXlab platform.
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A novel minimal cut-based algorithm to find all minimal Capacity Vectors for multi-state flow networks
European Journal of Operational Research, 2020Co-Authors: Ding Hsiang Huang, Cheng-fu Huang, Yi-kuei LinAbstract:Abstract Real systems, such as computer systems, can be modeled as network topologies with vertices and edges. Owing to equipment failures and maintenance requirements, the capacities of edges have several states. Such systems are regarded as multi-state flow networks (MSFN). System reliability of an MSFN is the probability that the required flow (i.e., demand) can successfully be sent from the source to the sink. By adopting a minimal path (MP) approach, system reliability can be computed in terms of all minimal Capacity Vectors meeting the demand d. A minimal Capacity Vector is called a d-MP. Although several algorithms have been presented in the literature for finding all d-MP, improving efficiency in the search for all d-MP is always a challenge. A group approach with both the concepts of minimal cut and MP is developed in this study, narrowing the search range of feasible flow Vectors. An algorithm based on the group approach is then proposed to improve the efficiency of the d-MP search. According to the structure of the proposed algorithm, parallel computing can be implemented with significant improvement in the efficiency of the d-MP generation, where the proposed algorithm is compared with previous ones based on three benchmarks, in terms of CPU time.
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Reliability Evaluation of Production System With In-Line Stockers
IEEE Transactions on Reliability, 2020Co-Authors: Ping Chen Chang, Yi-kuei Lin, James C. ChenAbstract:A reliability evaluation method is proposed for production systems by applying the capacitated-flow production network (CFPN) model. In particular, this article considers in-line stockers to monitor and to avoid blockage and starvation in the CFPN. First, the minimal Capacity that all cells (group of machines) should provide to meet demand is generated. Second, status of stocker is monitored via the proposed “stocker volume check table” to calculate the volume usage of a stocker, and the stocker nonutilization is then obtained. Finally, the system reliability is derived in terms of the minimal Capacity Vector and stocker nonutilization. An important contribution of this article is to avoid complicated dependency calculation when multiple stockers are considered. A practical case of printed circuit board production is further studied to illustrate the applicability of the proposed method.
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Demand satisfaction and decision-making for a PCB manufacturing system with production lines in parallel
International Journal of Production Research, 2014Co-Authors: Yi-kuei Lin, Ping Chen ChangAbstract:This paper studies demand satisfaction and decision-making for a printed circuit board (PCB) manufacturing system. A performance indicator, the system reliability, is proposed to evaluate the demand satisfaction. In particular, two important characteristics, (i) multiple production lines in parallel and (ii) multiple repair actions, are considered in this study. The PCB manufacturing system is modelled as a stochastic-flow manufacturing network (SFMN) by the graphical transformation and decomposition techniques. Based on the network-structured SFMN, this paper develops an algorithm to generate all minimal Capacity Vectors that workstations should provide to satisfy a given demand. In terms of all minimal Capacity Vectors, the system reliability is derived. In addition, the reliable production policy is determined based on each single minimal Capacity Vector.
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Reliability evaluation according to a routing scheme for multi-state computer networks under assured accuracy rate
Annals of Operations Research, 2014Co-Authors: Yi-kuei Lin, Cheng-fu HuangAbstract:In many real-time networks such as computer networks, each arc has stochastic Capacity, lead time, and accuracy rate. Such a network is named a multi-state computer network (MSCN). Under the strict assumption that the Capacity of each arc is deterministic, the quickest path (QP) problem is to find a path that sends a specific amount of data with minimum transmission time. From the viewpoint of internet quality, the transmission accuracy rate is one of critical performance indicators to assess internet network for system administrators and customers. Under both assured accuracy rate and time constraint, this paper extends the QP problem to discuss the flow assignment for a MSCN. An efficient algorithm is proposed to find the minimal Capacity Vector meeting such requirements. The system reliability, the probability to send \(d\) units of data through multiple minimal paths under both assured accuracy rate and time constraint, can subsequently be computed. Furthermore, two routing schemes with spare minimal paths are adopted to reinforce the system reliability. The enhanced system reliability according to the routing scheme is calculated as well. The computational complexity in both the worst case and average case are analyzed.
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SYSTEM RELIABILITY WITH ROUTING SCHEME FOR A STOCHASTIC COMPUTER NETWORK UNDER ACCURACY RATE
International Journal of Industrial Engineering-theory Applications and Practice, 2013Co-Authors: Yi-kuei LinAbstract:Under the assumption that each branch’ Capacity of the network is deterministic, the quickest path problem is to find a path sending a specific of data from the source to the sink such that the transmission time is minimized. However, in many real-life networks such as computer systems, the Capacity of each branch is stochastic with a transmission accurate rate. Such a network is named a stochastic computer network. Hence, we try to compute the probability that d units of data can be sent through the stochastic computer network within both the time and accuracy rate constraints according to a routing scheme. Such a probability is a performance indicator to provide to managers for improvement. This paper mainly proposes an efficient algorithm to find the minimal Capacity Vector meeting such requirements. The system reliability with respect to a routing scheme then can be calculated.
Junghoon Lee - One of the best experts on this subject based on the ideXlab platform.
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ADHOC-NOW - Design of a hard real-time guarantee scheme for dual ad hoc mode IEEE 802.11 WLANs
Ad-Hoc Mobile and Wireless Networks, 2005Co-Authors: Junghoon Lee, Mikyung Kang, Gyung-leen ParkAbstract:This paper proposes and analyzes a message scheduling scheme and corresponding Capacity allocation method for the distributed hard real-time communication on dual Wireless LANs. By making the superframe of one network precede that of the other by half, the dual network architecture can minimize the effect of deferred beacon and reduce the worst case waiting time by half. The effect of deferred beacon is formalized and then directly considered to decide polling schedule and Capacity Vector. Simulation results executed via ns-2 show that the proposed scheme improves the schedulability by 36 % for real-time messages and allocates 9 % more bandwidth to non-real-time messages by enhancing achievable throughput for the given stream sets, compared with the network whose bandwidth is just doubled.
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Design of a hard real-time guarantee scheme for dual ad hoc mode IEEE 802.11 WLANs
Lecture Notes in Computer Science, 2005Co-Authors: Junghoon Lee, Mikyung Kang, Gyung-leen ParkAbstract:This paper proposes and analyzes a message scheduling scheme and corresponding Capacity allocation method for the distributed hard real-time communication on dual Wireless LANs. By making the superframe of one network precede that of the other by half, the dual network architecture can minimize the effect of deferred beacon and reduce the worst case waiting time by half. The effect of deferred beacon is formalized and then directly considered to decide polling schedule and Capacity Vector. Simulation results executed via ns-2 show that the proposed scheme improves the schedulability by 36 % for real-time messages and allocates 9 (% more bandwidth to non-real-time messages by enhancing achievable throughput for the given stream sets, compared with the network whose bandwidth is just doubled.
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RSFDGrC (2) - An efficient bandwidth management scheme for a hard real-time fuzzy control system based on the wireless LAN
Lecture Notes in Computer Science, 2005Co-Authors: Junghoon Lee, Mikyung Kang, Yongmoon Jin, Hanil Kim, Jinhwan KimAbstract:This paper proposes and analyzes bandwidth allocation and reclaiming schemes on wireless media to enhance the timeliness of the real-time messages and accordingly the correctness of fuzzy control decision. Bandwidth allocation scheme generates efficient round robin polling schedule represented as a Capacity Vector by directly considering the deferred beacon problem. The resource reclaiming scheme reassigns unused slot time to non-real-time traffic by extending the collision period without violating the hard real-time guarantee. The simulation results show that the proposed scheme can not only enhance the schedulability of wireless network by up to 18% but also give more bandwidth to the non-real-time traffic up to 5.3%, while the resource reclaiming scheme can maximally improve the achievable throughput by 11% for the given stream set.
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Design of an error control scheme for hard real-time communication on FDDI networks
Proceedings of IEEE. IEEE Region 10 Conference. TENCON 99. 'Multimedia Technology for Asia-Pacific Information Infrastructure' (Cat. No.99CH37030), 1Co-Authors: Junghoon Lee, Cheolmin KimAbstract:This paper describes a low-cost error control scheme for hard real-time communication on FDDI networks. As the existing bandwidth allocation schemes decide the Capacity Vector based on the worst case condition, there is usually extra available transmission time for each message stream. The proposed error control scheme uses this extra bandwidth for the retransmission of a subpacket, without additional bandwidth for the error control procedure. Simulation results shows that the proposed scheme enhances the deadline meet ratio by 50% at maximum.
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RTCSA - An error control scheme for Ethernet-based real-time communication
Proceedings of 3rd International Workshop on Real-Time Computing Systems and Applications, 1Co-Authors: Junghoon Lee, Seungjun ParkAbstract:This paper describes a low-cost error control scheme for transmission control based real-time communication, especially for TDMA-implemented Ethernet. As the bandwidth allocation scheme decides the Capacity Vector (or slot time) based on the worst case condition, there is usually extra available transmission time for each message stream. The proposed error control scheme uses this extra bandwidth for the retransmission of a subpacket, while it needs allocation of additional bandwidth for a retransmission request message. Simulation shows that the proposed scheme enhances the success ratio by 28% at maximum, exhibiting almost error-free transmission when error rate is less than 10/sup -5/ for the given stream sets.
Cheng-fu Huang - One of the best experts on this subject based on the ideXlab platform.
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A novel minimal cut-based algorithm to find all minimal Capacity Vectors for multi-state flow networks
European Journal of Operational Research, 2020Co-Authors: Ding Hsiang Huang, Cheng-fu Huang, Yi-kuei LinAbstract:Abstract Real systems, such as computer systems, can be modeled as network topologies with vertices and edges. Owing to equipment failures and maintenance requirements, the capacities of edges have several states. Such systems are regarded as multi-state flow networks (MSFN). System reliability of an MSFN is the probability that the required flow (i.e., demand) can successfully be sent from the source to the sink. By adopting a minimal path (MP) approach, system reliability can be computed in terms of all minimal Capacity Vectors meeting the demand d. A minimal Capacity Vector is called a d-MP. Although several algorithms have been presented in the literature for finding all d-MP, improving efficiency in the search for all d-MP is always a challenge. A group approach with both the concepts of minimal cut and MP is developed in this study, narrowing the search range of feasible flow Vectors. An algorithm based on the group approach is then proposed to improve the efficiency of the d-MP search. According to the structure of the proposed algorithm, parallel computing can be implemented with significant improvement in the efficiency of the d-MP generation, where the proposed algorithm is compared with previous ones based on three benchmarks, in terms of CPU time.
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Reliability evaluation according to a routing scheme for multi-state computer networks under assured accuracy rate
Annals of Operations Research, 2014Co-Authors: Yi-kuei Lin, Cheng-fu HuangAbstract:In many real-time networks such as computer networks, each arc has stochastic Capacity, lead time, and accuracy rate. Such a network is named a multi-state computer network (MSCN). Under the strict assumption that the Capacity of each arc is deterministic, the quickest path (QP) problem is to find a path that sends a specific amount of data with minimum transmission time. From the viewpoint of internet quality, the transmission accuracy rate is one of critical performance indicators to assess internet network for system administrators and customers. Under both assured accuracy rate and time constraint, this paper extends the QP problem to discuss the flow assignment for a MSCN. An efficient algorithm is proposed to find the minimal Capacity Vector meeting such requirements. The system reliability, the probability to send \(d\) units of data through multiple minimal paths under both assured accuracy rate and time constraint, can subsequently be computed. Furthermore, two routing schemes with spare minimal paths are adopted to reinforce the system reliability. The enhanced system reliability according to the routing scheme is calculated as well. The computational complexity in both the worst case and average case are analyzed.
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Stochastic computer network with multiple terminals under total accuracy rate
Journal of Zhejiang University SCIENCE C, 2013Co-Authors: Yi-kuei Lin, Cheng-fu HuangAbstract:From the viewpoint of service level agreements, data transmission accuracy is one of the critical performances for assessing Internet by service providers and enterprise customers. The stochastic computer network (SCN), in which each edge has several capacities and the accuracy rate, has multiple terminals. This paper is aimed mainly to evaluate the system reliability for an SCN, where system reliability is the probability that the demand can be fulfilled under the total accuracy rate. A minimal Capacity Vector allows the system to transmit demand to each terminal under the total accuracy rate. This study proposes an efficient algorithm to find all minimal Capacity Vectors by minimal paths. The system reliability can then be computed in terms of all minimal Capacity Vectors by the recursive sum of disjoint products (RSDP) algorithm.
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Stochastic computer network under accuracy rate constraint from QoS viewpoint
Information Sciences, 2013Co-Authors: Yi-kuei Lin, Cheng-fu HuangAbstract:In the past, the main concerns for competitive enterprise environment of computer networks were data transmission delays and costs. However, from the viewpoint of quality of service (QoS), internet service providers and enterprise customers are increasingly focusing on data accuracy during transmission. This study extends a stochastic computer network (SCN) to evaluate the system reliability, where the system reliability is the probability that demand can be transmitted through the SCN under the total accuracy rate. In such an SCN, each arc has several capacities, and an accuracy rate. We can regard the system reliability as a measurable index for assessing the SCN performance. A lower boundary point for (d,K) is a minimal Capacity Vector, which allows the system to transmit demand d under the total accuracy rate K. Using the minimal paths, we propose an efficient algorithm to find all lower boundary points for (d,K). The system reliability can then be computed in terms of all lower boundary points for (d,K) by the recursive sum of disjoint products (RSDP) algorithm. Several numerical examples are demonstrated to illustrate the utility, efficiency, and effectiveness of the proposed algorithm.
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Reliability evaluation subject to assured accuracy rate and time for stochastic unreliable-node computer networks
Journal of Statistical Computation and Simulation, 2012Co-Authors: Yi-kuei Lin, Cheng-fu HuangAbstract:In many real-life networks such as computer networks, branches and nodes have multi-state Capacity, lead time, and accuracy rate. The network with unreliable nodes is more complex to evaluate the reliability because node failure results in the disabled of adjacent branches. Such a network is named a stochastic unreliable-node computer network (SUNCN). Under the strict assumption that each component (branch and node) has a deterministic Capacity, the quickest path (QP) problem is to find a path sending a specific amount of data with minimum transmission time. The accuracy rate is a critical index to measure the performance of a computer network because some packets are damaged or lost due to voltage instability, magnetic field effects, lightning, etc. Subject to both assured accuracy rate and time constraints, this paper extends the QP problem to discuss the system reliability of an SUNCN. An efficient algorithm based on a graphic technique is proposed to find the minimal Capacity Vector meeting such const...
Enyu Yao - One of the best experts on this subject based on the ideXlab platform.
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Capacity inverse minimum cost flow problems under the weighted Hamming distance
Optimization Letters, 2015Co-Authors: Longcheng Liu, Enyu YaoAbstract:Given a network N(V, A, u, c) and a feasible flow \(x^0\), the inverse minimum cost flow problem is to modify the Capacity Vector or the cost Vector as little as possible to make \(x^0\) form a minimum cost flow of the network. The modification can be measured by different norms. In this paper, we consider the Capacity inverse minimum cost flow problems under the weighted Hamming distance, where we use the weighted Hamming distance to measure the modification of the arc capacities. Both the sum-type and the bottleneck-type cases are considered. For the former, it is shown to be APX-hard due to the weighted feedback arc set problem. For the latter, we present a strongly polynomial algorithm which can be done in \(O(n\cdot m^2)\) time.
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FAW-AAIM - Weighted inverse minimum cut problem under the sum-type hamming distance
Frontiers in Algorithmics and Algorithmic Aspects in Information and Management, 2012Co-Authors: Longcheng Liu, Yong Chen, Enyu YaoAbstract:An inverse optimization problem is defined as follows: Let S denote the set of feasible solutions of an optimization problem P , let c be a specified cost (Capacity) Vector , and x 0∈S . We want to perturb the cost (Capacity) Vector c to d such that x 0 becomes an optimal solution of P with respect to the cost (Capacity) Vector d , and to minimize some objective functions. In this paper, we consider the weighted inverse minimum cut problem under the sum-type Hamming distance. First, we show the general case is NP-hard. Second we present a combinatorial algorithm that run in strongly polynomial time to solve a special case.
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A weighted inverse minimum cut problem under the bottleneck type hamming distance
Asia-Pacific Journal of Operational Research, 2007Co-Authors: Longcheng Liu, Enyu YaoAbstract:An inverse optimization problem is defined as follows. Let S denote the set of feasible solutions of an optimization problem P, let c be a specified cost (Capacity) Vector, and x0 ∈ S. We want to perturb the cost (Capacity) Vector c to d so that x0 is an optimal solution of P with respect to the cost (Capacity) Vector d, and to minimize some objective function. In this paper, we consider the weighted inverse minimum cut problem under the bottleneck type Hamming distance. For the general case, we present a combinatorial algorithm that runs in strongly polynomial time.
Gyung-leen Park - One of the best experts on this subject based on the ideXlab platform.
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ADHOC-NOW - Design of a hard real-time guarantee scheme for dual ad hoc mode IEEE 802.11 WLANs
Ad-Hoc Mobile and Wireless Networks, 2005Co-Authors: Junghoon Lee, Mikyung Kang, Gyung-leen ParkAbstract:This paper proposes and analyzes a message scheduling scheme and corresponding Capacity allocation method for the distributed hard real-time communication on dual Wireless LANs. By making the superframe of one network precede that of the other by half, the dual network architecture can minimize the effect of deferred beacon and reduce the worst case waiting time by half. The effect of deferred beacon is formalized and then directly considered to decide polling schedule and Capacity Vector. Simulation results executed via ns-2 show that the proposed scheme improves the schedulability by 36 % for real-time messages and allocates 9 % more bandwidth to non-real-time messages by enhancing achievable throughput for the given stream sets, compared with the network whose bandwidth is just doubled.
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Design of a hard real-time guarantee scheme for dual ad hoc mode IEEE 802.11 WLANs
Lecture Notes in Computer Science, 2005Co-Authors: Junghoon Lee, Mikyung Kang, Gyung-leen ParkAbstract:This paper proposes and analyzes a message scheduling scheme and corresponding Capacity allocation method for the distributed hard real-time communication on dual Wireless LANs. By making the superframe of one network precede that of the other by half, the dual network architecture can minimize the effect of deferred beacon and reduce the worst case waiting time by half. The effect of deferred beacon is formalized and then directly considered to decide polling schedule and Capacity Vector. Simulation results executed via ns-2 show that the proposed scheme improves the schedulability by 36 % for real-time messages and allocates 9 (% more bandwidth to non-real-time messages by enhancing achievable throughput for the given stream sets, compared with the network whose bandwidth is just doubled.
