• The Transactions of the Korea Information Processing Society
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• v.2 no.4
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• pp.554-560
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• 1995

In this paper, we suggest a parallel algorithm to merge priority queues organized in two heaps, kheap and nheap of sizes k and n, correspondingly. Employing max(2$^{-1}$, $\ulcorner$(m＋1)/4$\lrcorner$'s processors, this algorithm requires O(log(n/k)＊log(n)) on an EREW-PRAM, where i is the height of the heap and m is the summation of sizes n and k. Also, when we run it on the MasPar machine, this method achieves a 33.934-fold speedup with 64 processors to merge 8 million data items which consist of two heaps of different sizes. So our parallel algorithm's EPU is close to 1, which is considered as an optimal speedup ratio.eedup ratio.

• Korean Management Science Review
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• v.28 no.1
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• pp.107-116
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• 2011

The automated teller machine (ATM) is developed as a system to provide customers with an easy deposit and withdrawal of their money without time restriction and be served for 24 hours. Today, ATM is come up to the level of an unmanned branch. The automatic financing system is developed as an essential one for dealing with the rationalization of management and the globalization of financing in order to improve the efficiency of financial management work and increase the customer service quality. With reducing the operational cost of financial organizations through the efficient maintenance operation of ATM and increasing the service quality through the maximization of its processing efficiency, this study is to draw the scheme to ensure the competitiveness among the finance companies. The importance of ATM is highly recognized as the utilization of ATM is increased and the processing function is extended, but ATM is quite vulnerable to the malfunction occurred during the nighttime after banking hours. The ATM maintenance is done through consignment to the specialized maintenance company. The efficient operation of ATM maintenance work is important to the satisfaction of customer using ATM in the nighttime.

• Journal of Korean Institute of Industrial Engineers
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• v.27 no.1
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• pp.111-117
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• 2001

Most of the techniques for the performance estimation of unit-load AS/RS are a static model or computer simulation. Especially, their models have been developed under the assumption that the Storage/Retrieval (S/R) machine performs either single command(SC) or dual command(DC) only. In reality, depending on the operating policy and the status of the system at a particular time, the S/R machine performs a SC or a DC, or becomes idle. In order to resolve this weak point, we propose a stochastic model for the performance estimation of unit-load ASIRS by using a M/G/1 queueing model with a single server and two queues. Server utilization, expected numbers of waiting storage and retrieval commands and mean time spent in queue and system are found.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.8
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• pp.3021-3027
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• 2010

Example-based chatBot generates a response to user's utterance by searching the most similar utterance in a collection of dialogue examples. Though finding an appropriate example is very important as it is closely related to a response quality, few studies have reported regarding what features should be considered and how to use the features for similar utterance searching. In this paper, we propose a machine learning framework which uses various linguistic features. Experimental results show that simultaneously using both semantic features and lexical features significantly improves the performance, compared to conventional approaches, in terms of 1) the utilization of example database, 2) precision of example matching, and 3) the quality of responses.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.3
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• pp.40-48
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• 2009

In this article, scheduling of a casting sequence is studied in a casting foundry which must deliver products according to the Just-in-time(JIT) production policy of a customer. When a foundry manufactures a variety of casts with an identical alloy simultaneously, it frequently faces the task of production scheduling. An optimal casting schedule should be emphasized in order to maximize the production rate and raw material efficiency under the constraints of limited resources; melting furnaces and operation time for a casting machine. To solve this practical problem-fulfilling the objectives of casting the assigned mixed orders for the highest raw material efficiency in a way specified by the customer's JIT schedule, we implement simple integer programming. A simulation to solve a real production problem in a typical casting plant proves that the proposed method provides a feasible solution with a high accuracy for a complex, multi-variable and multi-constraint optimization problem. Employing this simple methodology, a casting foundry having an automated casting machine can produce a mixed order of casts with a maximum furnace utilization within the due date, and provide them according to their customer's JIT inventory policy.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.12
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• pp.1042-1047
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• 2003

The goal of this research is to implement a PC-based remote control system of ion implanter using Visual Basic programming. Presently, skilled process engineers are required to regularly setup and adjust implanter parameters. Any reduction in the number of production hours devoted to ion beam implanter setup or recalibration after a species change would represent substantial improvements in both manpower and equipment utilization. An optical communication system for the remote control and telemetry in the operation of the 50kev potential was designed and constructed. This system enables continuous and safe operation of the ion implanter and can be the basis for the automation. The isolation characteristics of optical fiber were 10kV/cm, and performance tests of the system under the intense noise environment during the implanter operations showed satisfactory results. This system is designed to completely replace the existing human-machine interface with many new functions. This paper describes the important components of the system including system architecture and software development. It is expected that this system can be used for the communication and control purpose in the high noise environments such as the operation of the MeV energy implanter or other high power, high noise systems.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.2 s.110
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• pp.30-37
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• 2005

Compact system as a new and highlighted trend in papermaking technology gives papaermakers many advantages including simple and clean process, quick grade change, minimized liquid volume, and so on. It is possible to remove an existed chest for simplifying system and more utilization of space, but its effect on process and product stability must be evaluated qualitatively in advance. For this purpose, process simulation can be applied. We examined the effect of disturbances on process and product in a papermaking system with and without machine chest using dynamic simulation. As compared with the existed system, the paprmaking system without machine chest showed twice or more variation in process and product and required longer time for stabilization.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.1
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• pp.34-39
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• 2014

In cognitive radios, secondary users can use the spectrum exclusively allocated to a primary wireless system if the secondary users detect the spectrum in idle states. Because the secondary users can utilize the idle state of the spectrum, the utilization rate of the spectrum can be improved. The idle states can be detected by using secondary users' sensing schemes. However, the wireless channel environment where secondary users perform the spectrum sensing is not very friendly to secondary users because the signal-to-noise ratio of the received primary signal is very low. Hence, cooperative sensing scheme where more than one secondary user take part in the spectrum sensing is generally used in cognitive radios. In this paper, we investigate the cooperative sensing performance for machine-to-machine communication devices operated by batteries with limited energy. In general, the energy consumed for the spectrum sensing increases as the length of the sensing period and the number of cooperative sensing nodes. Accordingly, even though the total amount of the consumed energy is the same, an energy allocation methodology how to distribute the energy to the sensing period and sensing nodes can achieve the optimum sensing performance, which is numerically analyzed.

• Journal of KIISE
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• v.42 no.11
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• pp.1452-1458
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• 2015

Korean Morphological Analysis is a difficult process. Because Korean is an agglutinative language, one of the most important processes in Morphological Analysis is Morpheme Recovery. There are some methods using Heuristic rules and Pre-Analyzed Partial Words that were examined for this process. These methods have performance limits as a result of not using contextual information. In this study, we built a Korean morpheme recovery system using deep learning, and this system used word embedding for the utilization of contextual information. In '들/VV' and '듣/VV' morpheme recovery, the system showed 97.97% accuracy, a better performance than with SVM(Support Vector Machine) which showed 96.22% accuracy.

• Solar Energy
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• v.18 no.3
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• pp.81-87
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• 1998

Solar energy has been experiencing renewed interest because of the recent economical crisis in Korea. Absorption cooling is one of the promising solar energy utilization technologies. In this study the dynamic performance of a solar driven absorption cooling machine(SDACM) was numerically investigated. The simulated machine is a commercially available water/LiBr single effect absorption chillers driven by hot water from solar collectors. The present study has been directed to investigate the dynamic behavior of a solar cooling system including an absorption chiller, solar collector, a hot water storage tank, fan coil units, and the air-conditioned space. The operation of the system was simulated for 9 hours in varying operation conditions. The variation of temperature and concentration in the system components, and that of heat transfer rates in the system were obtained. It was also found that the room temperature was maintained near the desired value by controlling the mass flow rate of hot water.