• Journal of Practical Engineering Education
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• v.7 no.1
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• pp.17-23
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• 2015

Growing worldwide interest in software and spread awareness of the need for education. A software-driven society realization strategy will achieve mandatory training on software. This policy will be applied from middle school students in 2015. Students who are interested in computers, like many positive responses, student learning may seem hard to have a negative reaction. Thus, the present obligation as simple in practice education only and discarded before actually lost interest awarded a systematic education does not work properly, but rather that education could happen to entirely discard turn our attention. Accordingly, what you need is to have a systematic training from the basics that I need to worry about software that can recognize easy and fun. In this paper, we propose a hardware and basic software that allows you to proceed software training more easy and efficient as it can be modified and applied to the program in the production unit to learn programming tools and programming languages.

• Journal of Korean Institute of Industrial Engineers
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• v.27 no.3
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• pp.233-238
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• 2001

This paper deals with demand forecasting of parts in an automobile model which has been extinct. It is important to estimate how much inventory of each part in the extinct model should be stocked because production lines of some parts may be replaced by new ones although there is still demands for the model. Furthermore, in some countries, there is a strong regulation that the automobile manufacturing company should provide customers with auto parts for several years whenever they are requested. The major characteristic of automobile parts demand forecasting is that there exists a close correlation between the number of running cars and the demand of each part. In this sense, the total demand of each part in a year is determined by two factors, the total number of running cars in that year and the failure rate of the part. The total number of running cars in year k can be estimated sequentially by the amount of shipped cars and proportion of discarded cars in years 1, 2,$\cdots$, i. However, it is very difficult to estimate the failure rate of each part because available inter-failure time data is not complete. The failure rate is, therefore, determined so as to minimize the mean squared error between the estimated demand and the observed demand of a part in years 1, 2,$\cdots$, i. In this paper, data obtained from a Korean automobile manufacturing company are used to illustrate our model.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.10a
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• pp.221-226
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• 2005

Gifford(1992, 1993, 1997, 1998)는 제한적 주의력(limited attention)의 관점에서 벤처경영자, R&D 관리자, 혁신자, 벤처 캐피탈의 의사결정을 연구하였다. 창업경영자 (entrepreneurs)는 기술 개발, 제품디자인 개발, 원자재 확보, 제품 생산, 유통채널 확보, 가격정책 결정, 판매촉진 및 마케팅정책 결정 등의 다양한 경영활동을 수행하고 끊임없이 창업기회(entrepreneurial opportunities)를 추구하는 사람이다. Gifford 는 벤처 경영자를 창업기회와 다양한 경영활동의 포트폴리오(portfolio)를 수행하고 관리하는 대리인으로 간주한 '마술사 모형(Juggler model)' 을 제시하고 이익극대화의 관점에서 대리인의 의사결정을 분석하였다. 그녀는 모형을 통하여 특정시점을 지난 기존 메뉴를 포기 하고 새로운 창업기회를 평가하는 '포기정책(discard policy)' 과 아울러 기존 메뉴를 관리한 이후 새로운 창업기회를 평가하는 '연령검사(age inspection)' 를 동시에 사용한다는 결과를 도출하였다. 본 논문은 Gifford의 마술사 모형(Juggler model)을 수정, 발전시켜 창업경영자의 의사결정을 분석하였다. Gifford의 모형은 성장하지 않는 창업기회의 포트폴리오 결정에 대한 모형이기 때문에 창업기회의 성장성이 벤처경영자의 의사결정에 어떤 영향을 미치는가에 대한 논의가 전혀 없었다. 본 논문에서는 창업경영자를 기업가적 활동을 수행하는 사람으로 정의하고 벤처경영자의 의사결정을 분석하였다. 성장률이 큰 기업에서 기업가적 활동을 수행할 때 창업경영자가 창출하는 기업의 현재가치는 크게 증가하게 되는 반면 성장률이 떨어지는 기업에서 기업가적 활동을 수행할때 창업경영자가 창출하는 기업의 현재가치는 크게 감소하게 된다. 또, 창업경영자는 성장률이 큰기업을 선택하면 관리횟수가 줄어들게 되고 이익의 감소 없이 빠르게 수확할 수가 있다. 국가의 정책과 제도가 창업경영자를 보다 성 장률이 높은 기업에서 기업가활동을 하게 한다면 국가경제의 성장속도는 빨라지게 될 것이다.

• Journal of KIISE:Information Networking
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• v.27 no.2
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• pp.197-205
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• 2000

This paper proposes and evaluates a scheme which enhances real-time performance on the Ethernet-based residential network where cable length is very short and most of traffic passes through a specific device. The scheme aims at enhancing deadline meet ratio of the real-time traffic, for example, video stream by means of applying the functionalities such as queue discrimination and early packet discard as well as maintaining network load properly. The design includes the description on hardware interfaces along with the software modules such as scheduler, device driver and connection manager. The simulation results via SMPL suggest that the proposed network can be used as a cost-effective residential network. We also measure the permissible bandwidth for non-real-time traffic without degrading the performance of real-time traffic.

• Proceedings of the Korea Contents Association Conference
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• 2006.05a
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• pp.128-131
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• 2006

There are two traditional scheduling methods known as PQ and WRR in the DiffServ network, however, these two scheduling methods have some drawbacks. In this paper, we propose an algorithm that can be adopted in WRR scheduler with making up for weak points of PQ and WRR. The proposed algorithm produces the control discipline by the fuzzy theory to dynamically assigns the weight of WRR scheduler with checking the Queue status of each class. To evaluate the performance of the proposed algorithm, We accomplished a computer simulation using NS-2. In result, the proposed algorithm enhances the packet discard rate at the EF class than WRR scheduling method and the AF4 class than PQ scheduling method.

• Korean Chemical Engineering Research
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• v.44 no.3
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• pp.319-322
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• 2006

In this paper, the methodology of life-cycle assessment was applied to an ethanol production process based on fermentation. The purpose of the assessment was to quantify environmental performance of the process and to prepare a basis for environmental comparisons with the ethanol production process based on catalytic reaction. The assessment was carried only on the stages of raw material acquisition through ethanol manufacture since it was assumed that ethanol from both processes had the same environmental impacts through its use and discard. The assessment results showed that the major environmental impact came from the sub-process of producing starch from corn and the most severe burden was generated in the form of acidification and greenhouse effect.

• Korean Chemical Engineering Research
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• v.44 no.3
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• pp.323-327
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• 2006

In this paper, the methodology of life-cycle assessment was applied to an ethanol production process based on catalytic reaction. The environmental performance of the process was quantified and compared with that of the fermentation process. The purpose of the assessment was to develop design guidelines for the environmentally better ethanol production. The assessment was carried only on the stages of raw material acquisition through ethanol manufacture since it was assumed that ethanol from two processes had the same environmental impacts through its use and discard. The inventory analysis of the catalytic process resulted in that carbon dioxide from methanol production was the major environmental impact. The impact assessment showed that the fermentation process was environmentally better than the catalytic one. Suggestions for environmental improvement of the catalytic process were prepared based on the assessment results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.9A
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• pp.1372-1382
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• 1999

The major source of errors in high-speed networks such as Broadband ISDN(B-lSDN) is buffer overflow during congested conditions. These congestion errors are the dominant sources of errors in 1high-speed networks and result in cell losses. Conventional communication protocols use error detection and retransmission to deal with lost packets and transmission errors. However, these conventional ARQ(Automatic Repeat Request) methods are not suitable for the high-speed networks since the transmission delay due to retransmissions becomes significantly large. As an alternative, we have presented a method to recover consecutive cell losses using forward error correction(FEC) in ATM(Asynchronous Transfer Mode)networks to reduce the problem. The performance estimation based on the cell discard process model has showed our method can reduce the cell loss rate substantially. Also, the performance estimations in ATM networks by interleaving and IP multicast service are discussed.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.215-217
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• 2005

There are two types of packet loss probabilities used in both the network layer and the physical layer within the wireless transmitter such as a queueing discard probability and transmission loss probability. We analyze these loss performances in order to guarantee Quality of Service (QoS) which is the basic of the future network. The queuing loss probability is caused by a maximum allowable delay time and the transmission loss probability is caused by a wireless channel error. These two types of packet loss probabilities are not easily analyzed due to recursive feedback which, originates as a result at a queueing delay and a number of retransmission attempts. We consider a wireless transmitter to a M/D/1 queueing model. We configurate the model to have a finite-size FIFO buffer in order to analyze the real-time traffic streams. Then we present the approaches used for evaluating the loss probabilities of this M/D/1/K queueing model. To analyze the two types of probabilities which have mutual feedbacks with each other, we drive the solutions recursively. The validity and accuracy of the analysis are confirmed by the computer simulation. From the following solutions, we suggest a minimum of 'a Maximum Allowable Delay Time' for real-time traffic in order to initially guarantee the QoS. Finally, we analyze the required service rate for each type utilizing real-time traffic and we apply our valuable analysis to a N-user's wireless network in order to get the fundamental information (types of supportable real-type traffics, types of supportable QoS, supportable maximum number of users) for network design.

• The Research Journal of the Costume Culture
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• v.15 no.2 s.67
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• pp.284-298
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• 2007

Due to consumers' preferences for seeking a quality life and having more leisure time, comfortableness became a major criteria for selecting clothes for all age groups. This is why consumers' interests in knitwear increased recently. The purpose of this study is to analyze the knitwear consumption patterns such as style preferences, and consumer satisfaction with knitwear. Particularly, differences in age groups of consumers were analyzed. Data from 463 men and women participated in the study. Results indicated that consumers wear knits once or twice a week in average. After two to three years of consumption, they discard the knitwear. Among various apparel product categories, Consumers selected Cardigan to be the preferable knitwear product category. They preferred 100% cotton and achromatic or gray/brown color with solid fabrics. In general, consumers were most satisfied with colors and least satisfied with laundering of knitwear. Older consumers preferred knitwear to woven products, preferred pull-over style and valued feelings of softness and comfortableness when wearing knitwear. There were more differences in dissatisfaction factors than satisfaction factors according to the consumer age groups.