http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
단일 및 이중명령을 수행하는 자동창고 시스템의 성능분석
남진규(Jin-Gyu Nam),허선(Hur Sun),정석윤(Seok-Yun Jeong),김정기(Jeong-Kee Kim) 한국산업경영시스템학회 2004 한국산업경영시스템학회지 Vol.27 No.3
We consider an AS/RS(Automated Storage/ Retrieval System) which performs both of single and dual commands. The service times of single and dual commands are assumed to be differently distributed. Steady-state probabilities at the service completion epochs are calculated. Then, we transform the arrival rates of storage and retrieval commands into those of single and dual commands. Using this, we propose a non-preemptive queueing model with priority for the performance analysis of an AS/RS, and obtain approximated means of queue lengths and waiting times.
정석윤(Seo-Kyun Jeong),허선(Sun Hur),남진규(Jin-Gyu Nam) 한국산업경영시스템학회 2006 한국산업경영시스템학회지 Vol.29 No.1
In mobile ad-hoc networks(MANETs), nodes are mobile and network topology changes very frequently. The mobility of nodes does affect the system performance. There has been considerable attention on the mobility models, however, most work is confined to the simulation or test-bed. In this paper, we propose an analytical method to evaluate the performances of MANETs such as the average radio range dwell time of mobile nodes, link holding time, and transmission failure probability considering the node"s mobility. In the proposed model, MANETs consist of the multi-hop and multicasting routing paths. A simulation is done to validate our proposed analytical model.
허선(Hur, Sun),신동민(Shin, Dong Min),남진규(Nam, Jin gyu),이현(Lee, Hyun),김현우(Kim, Hyun Woo) 인하대학교 정석물류통상연구원 2008 인하대학교 정석물류통상연구원 연구총서 Vol.- No.-
Ubiquitous means integration of different networks and under which all operations should be processed in real time and prediction of data generation is not available. In ubiquitous environments, the types of information are vast and their forms are complex. Collection of these data may cause queuing situation and it affects system performances. In addition, most data generated in ubiquitous environments have time constraints, by which they become obsolete as time elapses. Therefore, it is essential to establish systems which accommodate the time constraints as the systems become more complicated. In this paper, we consider the characteristics of information in ubiquitous environments and build an analytical model to provide system performance measures which are required to compose and plan a system. We build a time constrained information processing model which deals with more than one types of information. We also analyze parameters which decide information processing time as one of the system measures and provide a method which satisfies the required level of it. Several numerical computations are given to illustrate the extent of effect that the parameters have on the system.
무선 환경 하에서 Slotted ALOHA 방식의 다중채널 경쟁에 대한 지연시간분석
허선(Sun Hur),김정기(Jeong-Kee Kim),남진규(Jin-Gyu Nam) 한국산업경영시스템학회 2005 한국산업경영시스템학회지 Vol.28 No.1
Slotted ALOHA(S-ALOHA) is widely used in local wireless network. We analyze the performance of contention-based model in wireless LAN using S-ALOHA protocol. We analyze the performance of binary exponential backoff (BEB) algorithm under the slotted ALOHA protocol : whenever a node's message which tries to reserve a channel is involved in a collision for the ith time, it chooses one of the next 2^i frames with equal probability and attempts the reservation again. We derive the expected access delay and throughput which is defined as the expected number of messages that reserve a channel in a frame. A simulation study is performed to verify our method.
차세대 통신네트워크에서 이동단말의 효율적인 동적제어 정책
김상용(Sang-Yong Kim),손재동(Jae-Dong Son),남진규(Jin-Gyu Nam) 대한산업공학회 2009 대한산업공학회 추계학술대회논문집 Vol.2009 No.10
Next generation communication systems are proposed in order to serve integrated multimedia services on heterogeneous networking environment. Supporting multimedia services with different quality of service (QoS) requirements in highly heterogeneous networking environment is very challenging and difficult task, and an optimal policy of unified call admission control (CAC) is needed to utilize the wired and wireless resources efficiently. In this paper, we propose a dynamic optimization on call admission control for next generation network. We consider three types of mobile stations (MSs) entering a network domain, namely, a new MS, a vertical hand-off MS, and a horizontal hand-off MS. If the MSs are moving between homogeneous systems, horizontal hand-off calls occur. On the other hand, if the MSs are moving between heterogeneous systems, vertical hand-off calls occur. We impose different costs on rejection of requests from these MSs, since the forced termination of an ongoing communication causes greater pain to a user than blocking a new MS. An optimal admission policy is obtained from a semi-Markov decision process with respect to the number of MSs present in a system cell domain. Based on this optimal policy, we calculate the probabilities of blocking each type of MS.