• 융합신호처리학회논문지
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• 제2권2호
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• pp.55-61
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• 2001

본 논문에서는 cdma2000 규격을 채용한 역방향 링크 동기식 DS-CDMA 시스템을 시뮬레이션 하여 시스템의 성능을 분석하였고, 파일롯 채널과 정보 채널 즉, 기존의 트래픽 채널간의 최적 전력비를 구하였다. cdma2000 시스템은 기존의 IS-95와는 달리 파일롯 채널을 이용하여 페이딩 채널을 추정하고 이를 이용하여 채널 환경에 의한 수신신호의 위상변화를 보강해 준다. 채널 추정길이 31pcg 심볼에서 파일롯 채널과 트래픽 채널의 최적 전력비를 구하였다. 또한 시스템에 전력 제어를 적용하여 목표 FER을 만족시키기 위한 required Eb/No를 구하였고, 다중의 사용자가 고속의 데이터를 동시에 전송할 때의 성능을 분석하였다.

• 건축역사연구
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• 제17권6호
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• pp.29-44
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• 2008

This paper analyses the railroad trunk line constructed in the Korea since the end of the 19th century. The analysis consists of the following problematics. 1) The process of the decision of the railroad route 2) The relationship of the location of Eupchi and the stations By clarifying the above, the purpose of this paper is to clarify how the morphology of the city in Korea has been affected by the change in the relationship with Korea and Japan. The Empire of Japan has been reconnoitering the Korea since way before the formal contract for the railroad construction was signed. Therefore, the Empire of Japan had a very good understanding of the actual transportation system when it started the construction of the railroad. The railroad construction was used by the Empire of Japan to empower the control over the Korea. For this reason, the new railroad system was constructed as a different system from the former transportation system and the urban system was also affected. Also the relationship of the western powers and Japan around the turn of the 20th century defined the characteristic of the railway system as a pathway through the Korean peninsular to link Japan to the continent. Moreover, being apprehensive about the friction with the western, Japan located the railway stations to avoid the missionary land properties. This made it clear that the restraint relationship between Japan and the western affected the urban special structure.

• 약학회지
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• 제43권4호
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• pp.411-418
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• 1999

Intracerebroventricular (ICV) infusion of morphine (MOR) produces strong analgesia in man and animals. The analgesic effect is thought to be mediated by the centrifugal inhibitory control. But neural mechanisms of the analgesic effect of ICV morphine are not well understood. In the present study, we found that ICV MOR had dual actions on the activity of dorsal horn heurons: it produced both inhibition and excitation of dorsal horn neurons. Since MOR exerts its action via three different types of opioid receptors, we further sought to investigate if there are differential effects of opioid receptor agonists on dorsal horn neurons when administered intracerebroventricularly. Effects of ICV MOR were tested in 28 dorsal horn neurons of the spinal cord in the cat. ICV MOR inhibited, excited and did not affect the heat responses of dorsal horn neurons. ICV DAMGO and DADLE, $\mu$- and $\delta$-opioid agonist, respectively, exhibited the excitation of dorsal horn neurons. In contract, U-50488, a k-opioid agonist, exhibited both the inhibition and excitation of dorsal horn neurons. These results suggest that opioid receptors have different actions on activity of dorsal horn neuron and that the inhibitory action of k-opioid agonist may subserve the analgesia often produced by ICV MOR.

• 상하수도학회지
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• 제24권5호
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• pp.617-628
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• 2010

The operation performance of sewer rehabilitation projects conducted with Build-Transfer- Lease contract in Korea will be evaluated using the index of infiltration and inflow (I/I). Though I/I obtained at the fourth year should be initially evaluated based on the I/I values observed for the previous three years after the completion of sewer construction, the concrete methodology have not been proposed to rely on the so called 'performance evaluation committee'. This study suggests two statistical methodology to evaluate the I/I performance; the confidence interval method and the hypothesis-testing method. Assumed ten I/I values in each year for 20 years are used in this study. Two cases are analyzed and compared; case I to use as control data all I/I values for all years obtained before the evaluation year and case II to use I/I values for only 3 years before the evaluation year. As a result, case II tends to have relatively higher scores than case I, reflecting the low mean I/I values at the initial years.

• 대한안전경영과학회지
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• 제14권1호
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• pp.147-154
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• 2012

The medium and small logistic companies that have an outsourcing contract from the large corporation are encountered with a problem to introduce the ERP system to their current business environment due to following risk of change in current business environment, high cost involved in investment, and lack of understanding of business requirement of ERP. Instead of build their own ERP system, the small and medium logistic companies are using the large corporation's ERP system and get the benefit of efficiency in management and control process. Therefore, it is more like the organization hierarchy, not collaboration between the medium and small companies with the large corporation. In this study, the survey method to find out how the medium and small logistic companies understand the importance of ERP system on continuous growth of business by AHP. as result, they are recognized. The benefit of the ERP system as having much effect on business competitiveness.

• 농업과학연구
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• 제24권2호
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• pp.138-144
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• 1997

Korean agricultural and rural economics has been gotten more difficult through the introduction of economics system under the control of IMF before problems from open market system under WTO get to be settled. Export should be promoted to get the advantage of open market system and to get over today's economic crisis from shortage of foreign currency. Fortunately, Korea adjoins Japan that is largest importing country of agricultural products in a world, therefore Korean Agricultural products has advantage in export to Japan through open market system. Puyo tomato, specialized agricultural products in Chungman province, has been exported 42.2M/T to Japan from 1994 year to 1996 year. But such exported amount was so small that is less than a 1% of total tomato product in Puyo area. Reasons why export volume to Japan was so small were non standard commodities, non performance of export contract, unfavorable price condition, etc.. But it was major reason that missed optimal exporting period. Therefore this study is aimed at finding optimal period exporting Puyo mini tomato to Japan. According to result of analysis based on monthly price and carried quality data of major tomato market between Korea and Japan, it has more comparative advantage that we export tomato during Period of Dec-Feb. rather than March-May which is currently major exporting period.

• 한국IT서비스학회지
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• 제7권1호
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• pp.167-193
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• 2008

Clients' outsourcing strategies noted in the IT outsourcing literature generate varying levels of client dependence on vendors. This study investigates clients' efforts to mitigate such dependence by utilizing multiple vendors. We use the theoretical lenses of resource dependency and opportunism to study this phenomenon. Specifically. we consider degree of outsourcing, duration of contract, and externalization of control as strategic choices that engender vulnerabilities that clients seek to offset by using multiple vendors. This study then considers the basis of the outsourcing relationships, clients' satisfaction with the relationships. and clients' IT workforce size as conditions that induce clients' concerns about vendor opportunism. This study argues that these conditions can exacerbate clients' experience of vulnerability. further encouraging clients' use of multiple vendors. The research model developed is tested in a survey of firms in South Korea. Results suggest a strong impact of outsourcing strategic choices on the number of vendors used by clients. The anticipated moderating effects of opportunism were only weakly supported by the data though. Theoretical and practical implications of the results are considered and suggestions for future research are offered.

• 산경연구논집
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• 제12권5호
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• pp.7-16
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• 2021

Purpose: This study intends to examine how VMI with consignment performs over time and find out its on-going impacts on the individual supply chain member's achievement. Research design, data, and methodology: This study formulates the mathematical model that represents two-stage supply chain system. By analyzing the numerical examples, this study compares VMI with consignment with the traditional system. Results: VMI with consignment eventually makes higher supply chain profit than the traditional system, even though it's early performance is poor. The influence of VMI with consignment on the performance of the supply chain member is distinct depending on the individual member and time. The consignment may not be helpful to increase the system profit, but it reduces the manufacturer's burden of costs. Conclusions: VMI with consignment improves the supply chain performance after all, and it still takes times until its benefit becomes fully realized. To be a successful collaboration program, VMI with consignment requires a carefully designed incentive scheme that provides the timely compensation to the individual supply chain members. This study also finds out that the consignment contract of this collaboration program plays a role of financially supporting the manufacturer at the early stage of its implementation.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.42-49
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• 2022

In recent years, Owner, Architects, and Contractor are increasingly collaborating with each other from pre construction phase in construction projects, which is called Early Contractor Involvement (ECI). In Japan, the ECI method has been introduced in several public building projects since 2015. The purpose of this study is mainly to clarify the characteristics of the ECI method in Japan and to compare the contract clauses of the ECI method in the UK and the USA. The results of the survey are as follows. (1) the ECI method was supposed to make it possible to achieve appropriate quality, cost, and construction period by reflecting Contractor's technology and know-how in the design documents and specifications. (2) According to the database, there were 27 cases of the ECI method in Japan from 2015 to 2021, of which 13 cases for which bidding information could be obtained had a variety of technical proposals, mainly VE proposals, depending on the project characteristics. (3), Japan's ECI method has very much in common with SBC + PCSA in the UK. On the other hand, ECI Method in Japan differs from in the UK in that Owner, Architect, and Contractor enter into a partnership agreement, which is similar to ConsensusDocs CD541 in the USA. (4) The ECI method in Japan has the following problems: Owner depends on Contractor for cost control, the division of roles among project members is complicated, and more work from Owner than the DBB method are required.

• 융합보안논문지
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• 제23권1호
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• pp.63-68
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• 2023

본 연구에서는 블록체인 프로토콜과 네트워크 보안에 관련해서 MITM공격 및 DoS/DDoS 공격 등에 강한 대응수준을 갖출 수 있도록 블록체인 구성과 스마트 컨트랙트 상의 암호화 키 관리 방안과 에 대해 연구한다. 암호화 통신 프로토콜과 인증강화를 통한 중간자 공격(MITM)등의 데이터보안 위협에 대응, 노드간의 로드밸런싱과 분산화 된 방식으로 DDoS 공격 대응, 안전한 코딩과 취약점 검사, 안전한 합의알고리즘에 의한 스마트 컨트랙트 보안 강화, 사용자 인증과 권한 부여 강화를 통한 액세스 제어 및 인증, 블록체인 코어 및 노드의 보안성 강화, 기타 블록체인 프로토콜 업데이트 및 보안 강화를 위한 모니터링 시스템 구축 등을 통해 보안성이 강화된 블록체인 기술을 활용할 수 있을 것으로 기대된다.