• 한국컴퓨터정보학회논문지
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• 제23권9호
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• pp.35-42
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• 2018

In this paper, we propose an optimal streaming service method based on Hybrid CDN/P2P architecture. Recently, video streaming utilizes a CDN (Content Delivery Network) operation technique based on a Proxy Server, which is an end node located close to a user. However, since CDN has a fixed network traffic bandwidth and data information exchange among CDNs in the network is not smooth, it is difficult to guarantee traffic congestion and quality of image service. In the hybrid CDN/P2P network, a data selection technique is used to select only the data that is expected to be continuously requested among all the data in order to guarantee the QoS of the user who utilizes the limited bandwidth efficiently. In order to search user requested data, this technique effectively retrieves the storage information of the constituent nodes of CDN and P2P, and stores the new image information and calculates the deletion priority based on the request possibility as needed. Therefore, the streaming service scheme proposed in this paper can effectively improve the quality of the video streaming service on the network.

• 산경연구논집
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• 제12권2호
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• pp.19-27
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• 2021

Purpose: This study investigated the impact of key factors such as service quality, perceived benefit and brand familiarity on a consumer's intention to order online food delivery (OFD). In addition, mediating effect of electronic word of mouth (e-WOM) between relationships among selected key variables and OFD purchase intention is also assessed. Research design, data and methodology: This explanatory, quantitative study employed convenience sampling and collected data through online structured questionnaire from 304 respondents who are users of OFD apps based in greater Klang valley region of Malaysia. The data was then subjected to normality and reliability assessment followed by confirmatory factor analysis, validity assessment and structural equation modelling using IBM SPSS AMOS 24.0. Results: Findings revealed that service quality, perceived benefits and brand familiarity affects purchase intention positively and significantly. Perceived benefits demonstrated highest impact on purchase intention followed by brand familiarity and service quality. Findings also suggest that e-WOM fully mediates relationship between brand familiarity and purchase intention, however, the same was not observed for remaining two variables. Conclusions: The study has enriched OFD literature by investigating impact of selected key factors on purchase intention in the context of OFD. Implications, limitations and future research avenues are then discussed.

• 한국IT서비스학회지
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• 제21권5호
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• pp.15-28
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• 2022

Recently, government agencies are actively adopting the platform model as a means of public policy. However, existing studies on the public platform are minimal and have focused on user experiences or the possibility of public usage of the platform model. Now the research concerning building governance structure and utilizing network effects of the platform after adopting the platform model in the public sector is keenly required. This study intended to ignite academic dialogue on the governance of public platforms in the context of digital transformation. This study focused on a case of the 'Special delivery,' a public delivery app established by Gyeonggi-do. In order to analyze the characteristics of the public platform and its governance structure, data were collected from press releases, policy reports, and news articles. Data was analyzed using the frame of Hagui's platform design factors and Ansell & Gash's collaborative governance model. The results of the public platform analyses showed 1) incompleteness in the value trade-off accounting, which was designed for platform business based on general cost-benefit analysis, and 2) a closed governance structure that limits direct participation of diverse user groups(i.e., service provider, customer) in order to enhance providers' utility by preventing customers' excessive online activities. The results of this study provided theoretical and policy implications regarding designing the strategy for accounting for value trade-offs and functioning governance structure for public platforms.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.411.2-411.2
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• 2002

In order to develope an optimum formulation for iontophoretic delivery of vitamine-C-2 phosphate. we have prepared 3 different formulations using hydrophilic polymers, such as poloxamer, carbo pol and HPMC and iontophoretic flux through skin from these hydrogel formulations was carried out. The effect of current density, drug concentration and current profile on flux was investigated. In-vitro flux study was performed at 36.5$^{\circ}C$, using side-by-side diffusion cell. Full-thickness hairless mouse skin was used for this work. (omitted)

• 반도체디스플레이기술학회지
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• 제21권2호
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• pp.90-94
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• 2022

In order to minimize the picking time when the products are released from the warehouse, they should be located close to the exit when the products are released. Currently, the warehouse determines the loading location based on the order of the requirement of products, that is, the frequency of arrival and departure. Items with lower requirement ranks are loaded away from the exit, and items with higher requirement ranks are loaded closer from the exit. This is a case in which the delivery time is faster than the products located near the exit, even if the products are loaded far from the exit due to the low requirement ranking. In this case, there is a problem in that the transit time increases when the product is released. In order to solve the problem, we use the idle time of the stocker in the warehouse to rearrange the products according to the order of delivery time. Temporal difference learning method using Q_learning control, which is one of reinforcement learning types, was used when relocating items. The results of rearranging the products using the reinforcement learning method were compared and analyzed with the results of the existing method.

• 대한교통학회지
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• 제28권5호
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• pp.91-106
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• 2010

최근 유류비와 도로혼잡의 증가, 환경오염에 대한 높은 관심으로 인하여 공급체인에서 수송부분에 대한 다양한 이슈가 제시되고 있다. 특히, 공급자와 소매상에 유리한 전략들이 운송회사 입장에서도 반드시 유리하지 않다는 이슈가 제시되면서 다양한 연구가 시도되기 시작하였다. 그러므로 본 연구에서는 전통적인 공급체인분석 관점에서 벗어나 운송회사 입장에서 재고전략 및 네트워크 구성에 따른 공급체인의 운영특성을 파악하고, 그에 따른 운송회사의 운영환경을 해석하고자 한다. 분석방법은 가상의 공급체인을 구성하고, 각 네트워크(분산형, 집중형)구성에서 EOQ재고전략(Economic Order Quantity)과 POQ재고전략(Periodic Order Quantity)에 따른 배송차량의 운영특성(배송차량의 적재율, 소요대수, 운행시간 등)을 TranCAD프로그램을 이용하여 분석하였다. 분석결과, 재고전략이 EOQ 재고전략에서 POQ 재고전략으로 바뀌면 운송회사가 보유해야 하는 배송차량과 운전자의 수를 줄일 수 있었으며, 차량 운행시간이 감소하였다. 또한 네트워크 구성이 분산형에서 집중형으로 변경되면 차량 적재율이 향상되고 차량 운행시간이 감소하였다. 즉, 운송회사 입장에서는 분산형 네트워크에서 EOQ 재고전략을 이용하는 것보다는 집중형 네트워크를 구성하고 POQ 재고전략을 이용하는 것이 유리하다는 사실을 확인 할 수 있었으며, 이러한 효과는 월 1,300만원의 고정비와 월 260만원의 변동비 절감효과를 가져왔다.

• 지능정보연구
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• 제28권4호
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• pp.119-133
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• 2022

음식 문화 및 산업과 관련한 대표적 특징들 중에는 음식 배달 주문 산업이 성장하고 있다는 것과 유튜브와 같은 1인 미디어에서의 소위 '먹는 방송' (먹방)이 최고의 인기 콘텐츠로 자리 잡았다는 사실 등을 거론할 수 있다. 본 연구는 이러한 배경에 근거하여 두가지 초점을 두어 연구하고자 하였다. 먼저, 유튜브 먹방과 먹방 댓글에서 확인되는 대중들의 감성이 관련 음식의 배달 이용 건수에 영향을 미치는지를 회귀분석 모형을 통하여 확인하고자 하였다. 다음으로, 대한민국에서 대표적인 주문 음식인 치킨의 배달 이용 건수 데이터와 유튜브 먹방 댓글 데이터와 날씨 데이터를 활용하여, 머신 러닝을 통한 치킨 배달 주문 예측 모형을 구현하였다. 2015년 6월 3일부터 2019년 9월 30일까지 총 1,580개의 데이터를 활용하였고, 날씨 변수로서의 온도, 습도, 강수량과 유튜브 먹방 변수로의 영상에 달린 댓글 수, 댓글의 긍정어 수, 중립어 수, 부정어 수 등을 수집하였다. 본 연구에 활용된 데이터의 유튜브 먹방과 먹방 댓글의 감성이 배달 이용 건수에 영향 미침을 확인하기위해 선형 회귀 방법론을 사용하였으며, 예측모델을 위해 사용된 머신 러닝은 Linear Regression, Ridge, Lasso, Random Forest, Gradient Boost이다. 본 연구를 통해 유튜브 먹방과 댓글의 감성이 배달 이용 건수에 영향 미침을 확인하였고 예측 모형 또한 기존 모델보다 성능이 좋아짐을 Root Mean Square Error 값을 통하여 확인하였다. 본 연구는 먹방의 광고 효과를 확인하였으며, 배달 업종에서의 경영에 활용할 수 있는 함의를 제공하고자 하였다.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제5권9호
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• pp.47-59
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• 1999

With the unparalleled rate of aging and rapid modernization, Korean society faces the situation in which it has to increase the supply of elderly care services dramatically in the near future. Among these services, nursing homes are considered as an essential alternative provision because Korea can no longer rely on traditional familism nor medical facilities for the care of her older population. It is necessary, therefore, to prepare a future plan for the delivery of nursing homes in Korea. This paper has identified elderly care context and analyzed elderly care facilities of Korea in the point of supply and utilization rate of nursing homes according to the region and type of facilities. On the bases of this analysis, the delivery planning of nursing homes in Korea has been proposed in order to increase welfare status of older people and efficient utilization of health care resources.

• 대한임베디드공학회논문지
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• 제8권6호
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• pp.329-337
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• 2013

In multihop routed ad hoc networks, the conventional store-and-forward delivery has been used. However, we may ask a question: "Is the store-and-forward delivery still the best?" This paper presents a pipeline-through MAC (PT-MAC) protocol for ad hoc networks, in which nodes have two 3-channel interfaces in order to use limited radio resources efficiently and improve network performance. The proposed protocol reduces end-to-end delay significantly in multihop routed transmission by exploiting a novel pipeline-through technique rather than using the conventional store-and-forward. This results in improved network performance without increasing control overhead. Our extensive performance study shows that the proposed PT-MAC shows 20-40 percent shorter end-to-end delay and 25-55 percent better goodput compared to the IEEE 802.11 DCF with two 3-channel interfaces.

• 반도체디스플레이기술학회지
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• 제14권1호
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• pp.45-49
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• 2015

Process gases with vapor or liquid phase as well as gas phase may experience alteration in itself or be contaminated in the fluid pipe to the process chamber. And thus it result in as particles or defects on the substrates in semiconductor, LCD, LED manufacturing. Purifiers and filters are used for control of contamination. However, none of detection device is available in the delivery line. In this paper, we propose simple device with lighting and sensing in order to predict contamination of the fluid or the tube wall. For some general purpose gases, it showed constant voltage output regardless of the flow rates. But, the smoke and the moisture in the air lowered the figure due to its concentration. Numerical values for several solid and liquid media were obtained. And, the operating temperature tendency was investigated.