• Journal of Korean Society of Industrial and Systems Engineering
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• v.13 no.21
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• pp.111-117
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• 1990

This paper treats the problem to schedule for train with low transit priority so as to maximizing the number that can be sent during given time without interfering with the fixed schedule for train with high transit priority in a track. We transform the this problem into Time-Expanded Network without traverse time through application of Ford-Fulkerson Model, develop a TENET GENerator(TENETGEN) and obtain the data of TENET using developed TENETGEN. Finally, we seek the optimal solution to these data with Dinic's Maximal-Flow Algorithm and examine the availability of our procedures in personal computer.

• Journal of the Korean Society of Safety
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• v.30 no.5
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• pp.108-113
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• 2015

Plastic injection moulding machine is widely used for many industrial field. It is classified into mandatory safety certification machinery in Industrial Safety and Health Act because of its high hazard. In order to prevent industrial accidents by plastic injection moulding machine, it is necessary for designer to identify hazardous factors and assess the failure modes to mitigate them. This study tabulates the failure modes of main parts of plastic injection moulding machine and how their failure has affect on the machine being considered. Failure Mode & Effect Analysis(FMEA) method has been used to assess the hazard on plastic injection moulding machine. Risk and risk priority number(RPN) has been calculated in order to estimate the hazard of failures using severity, probability and detection. Accidents caused by plastic injection moulding machine is compared with the RPN which was estimated by main regions such as injection unit, clamping unit, hydraulic and system units to find out the most dangerous region. As the results, the order of RPN is injection unit, clamping unit, hydraulic unit and system units. Barrel is the most dangerous part in the plastic injection moulding machine.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.10
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• pp.162-168
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• 2007

TCAM(Ternary content-addressable memory) has been widely used to perform fast routing lookup. It is able to accomplish the LPM(longest prefix matching) search in O(1) time without considering the number of prefixes and their lengths. As compared to software-based solutions, especially for IPv6, TCAM can oner sustained throughput and simple system architecture. However, There is no research for Priority-TCAM which can assign priority to each memory block. This paper addresses the difference or priority-TCAM compared to the existing TCAM and proposes CAO-PA algerian to manage the lookup table efficiently.

• Journal of the military operations research society of Korea
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• v.17 no.2
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• pp.113-122
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• 1991

This paper presents the Allocation Priority Scheme (APS) for multiprocessor system. The objective of APS is to reduce the time-complexity on a Physical Mapping Scheme(PMS). The PMS is to allocate the nodes of the Data Dependency Graph (DDG) to the multprocessors efficiently and effectively. The APS provides the priority to each node (vertex) in the DDG. In other words, the goal of the APS is to find a request resource mapping such that the total cost (time-complexity) is minimized. The special case in which all requests have equal priorities and all resoruces have equal precedences, and the comparisons between our APS and other schems are discussed in the paper. The APS provides the heuristic rules which are based on maximum height (MH), number of children nodes ($N_c$), number of father nodes ($N_f$), and computation time ($T_c$). The estimation moth of the computaion time is in the paper.

• Journal of Korean Institute of Industrial Engineers
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• v.25 no.1
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• pp.130-140
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• 1999

This paper deals with a priority queueing model in an ATM system. Two types of customers are considered. Type-1 customers have push-put priority over type-2 customers. Type-1 customers can enter the service only when the number of type-2 customers is less than a threshold T. We derive the joint probability of the number of customers in the buffer, the mean waiting time, and the loss probabilities of each type. We also propose an optimal control policy that satisfies a given quality of service.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.5
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• pp.218-225
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• 2001

This paper analyses the performance of network system using the CAN(Controller Area Network) protocol. Given messages are assumed to be scheduled by the DMS(Deadline Monotonic Scheduling) algorithm. The mathematical models for time-delay that can be occurred between CAN nodes are defined. The effectiveness of modeling is shown by comparing the difference of time-delay between simulations and practical experiments. We analyse the results according to the variation of factors, such as the number of nodes, the transmission speed, the message size and the number of aperiodic messages through simulation and confirm the real-time performance of lower priority messages. We also investigate the real-time performance of periodic messages when aperiodic message generates.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.443-445
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• 2002

In this paper, we present a novel efficient semaphore implementation scheme which diminishes completion time of high priority tasks and improves reliability of a system. The real-time system is constrained to complete their tasks in time. Especially, the task of a hard real-time system must meet its deadline under unfavorable conditions. In this paper, the number and sort of the locked semaphores, when an event occurred, decide whether the context switch should occur or not, so higher priority tasks diminish in their completion time. The experimental results show that the proposed method gives performance improvements in finish time of high priority tasks of about 11% over the Zuberi.

• Journal of Soil and Groundwater Environment
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• v.20 no.7
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• pp.1-12
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• 2015

The purpose of this study is to highlight the National Classification System related to cleanup the soil contaminated sites and to provide some guidance to address the priority management rank system before the remediation for Busan metropolitan city. Based on the previous soil investigation data, the quantitative classification of vulnerable areas for soil pollution was performed to successfully manage the contaminated sites in Busan. Ten evaluation factors indicating the high soil pollution possibility were used for the priority management ranking system and 10 point was assigned for each factor which was evenly divided by 10 class intervals. For 16 Gu/Guns in Busan, the score of each evaluation factor was assigned according to the ratio of the area (or the number) between in each Gu (or Gun) and in Busan. Ten scores for each Gu (or Gun) was summed up to prioritize the vulnerable Gu or Guns for soil pollution in Busan. Results will be available to determine the most urgent area to cleanup in each Gu (or Gun) and also to assist the municipal government to design a successful and cost-effective site management strategy in Busan.

• Journal of Multimedia Information System
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• v.6 no.4
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• pp.239-244
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• 2019

With the development of Cyber-Physical Systems(CPS), several technologies such as automation control, automotive and intelligent house systems have been developed. To enable communication among various components of such systems, several wired and wireless communication protocols are used. The Controller Area Network(CAN) is one of such wired communication protocols that is popularly used for communication in automobiles and other machinery in the industry. In this paper, we designed and implemented a response time analysis system for CAN communication. The reliable data transfer among various electronic components in a significant time is crucial for the smooth operation of an electric vehicle. Therefore, this system is designed to conveniently analyze the response time of various electronic components of a CAN enabled system. The priority for transmission of the messages in the CAN bus is determined by the message identifier. As the number of nodes increases the transmission of low priority messages is delayed due to the existence of higher priority messages on the bus. We used Raspberry Pi3 and PiCAN2 board to simulate the data transfer for studying the comparative delay in low priority nodes.

• Environmental Analysis Health and Toxicology
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• v.25 no.1
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• pp.41-55
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• 2010

The aims of this study were to develop the suitable "system software" in chemical ranking and scoring (CRS) for the food hazardous chemicals associated with environmental emission and to suggest the priority lists of food contamination by environmental-origined pollutants. Study materials were selected with reference to the priority pollutants list for environment and food management from domestic and foreign research and the number of study materials is 103 pollutants (18 heavy metals, 10 PBTs, 10 EDs, and 65 organic compounds). The Food-CRS-Korea system consisted of the environmental fate model via multimedia, transfer environment to food model, and health risk assessment by contaminated food intake. We have established that health risks of excess cancer risks, hazard quotients (HQs) by chronic toxicity and HQs by reproductive toxicity convert to score, respectively. The creditable scoring system was designed to consider uncertainty of quantitative risk assessment based on VOI (Value-Of-Information). The predictability of the Food-CRS-Korea model was evaluated by comparing the presumable values and the measured ones of the environmental media and foodstuffs. The priority lists based on emissions with background-level-correction are 15 pollutants such as arsenic, cadmium, and etc. The priority lists based on environmental monitoring date are 17 pollutants including DEHP, TCDD, and so on. Consequently, we suggested the priority lists of 13 pollutants by considering the several emission and exposure scenarios. According to the Food-CRS-Korea system, arsenics, cadmium, chromes, DEHP, leads, and nickels have high health risk rates and reliable grades.