• 한국정보시스템학회지:정보시스템연구
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• 제21권1호
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• pp.117-152
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• 2012

The purpose of this study was to identify the negative factors affecting personnel u-Learning acceptance and to analyze the interrelation among the factors in this research model. The two independent variables avoidable convenience and reliant convenience, based on pilot test results, and learning performance and perceived interactivity, based on the relevant literature, are used to examine the research model. The research problem was tested with data collected from 577 respondents in 23 universities. This study developed and empirically analyzed a model representing the relationship by using the Structural Equation Model. The major findings of this study are, firstly, that the higher reliant convenience is negatively affecting the degree of system use and learner’s satisfaction, whereas avoidable convenience is only affecting the learner’s satisfaction. Secondly, the higher learning performance and stronger perceived interactivity affects the degree of system use as well as learner’s satisfaction. Finally, the degree of system use affects the learner’s satisfaction.

• International Journal of Internet, Broadcasting and Communication
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• 제16권1호
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• pp.29-35
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• 2024

TCP is considered as one of the major candidate transport protocols even for constrained IoT networks..In our previous work, we investigated the congestion control mechanism of the uIP TCP. Since the uIP TCP sets the window size to one segment by default, managing the retransmission timer is the primary approach to congestion control. However, the original uIP TCP sets the retransmission timer based on the fixed RTO, it performs poorly when a radio duty cycling mechanism is enabled and the hidden terminal problem is severe. In our previous work, we proposed a TCP retransmission timer adjustment scheme for uIP TCP which adopts the notion of weak RTT estimation of CoCoA, exponential backoffs with variable limits, and dithering. Although our previous work showed that the proposed retransmission timer adjustment scheme can improve performance, we observe that the scheme often causes a node to set the retransmission timer for an excessively too long time period. In this work, we show that slightly modifying the dithering mechanism of the previous scheme is effective for improving TCP fairness.

• East Asian mathematical journal
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• 제40권3호
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• pp.295-306
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• 2024

We investigate the existence of multiple positive solutions of the following elliptic equation with a Schrödinger-type term: $$\begin{cases}-{\Delta}u+V(x)u={\lambda}f(u){\quad} x{\in}{\Omega},\\{\qquad}{\qquad}{\quad}u=0, {\qquad}\;x{\in}\partial{\Omega},\end{cases}$$, where 0 ∈ Ω is a bounded domain in ℝ^N , N ≥ 1, with a smooth boundary ∂Ω, f ∈ C[0, ∞), V ∈ L^∞(Ω) and λ is a positive parameter. In particular, when f(s) > 0 for 0 ≤ s < σ and f(s) < 0 for s > σ, we establish the existence of at least three positive solutions for a certain range of λ by using the method of sub and supersolutions.

• 대한산업공학회지
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• 제11권1호
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• pp.51-61
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• 1985

Major changes of the industrial engineering curricula in U.S.A. were analysed in three stages: 1938, 1958 and 1984. There are tendencies that the traditional plant operation oriented courses are combined and compressed to a few courses while the system oriented courses such as SA, OR, computer applications, man-machine systems are expanding. It will be necessary to organize a study group such as ASEE conducting further studies to meet our needs by upgrading the engineering curriculum for the coming 90's education.

• 통상정보연구
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• 제10권4호
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• pp.153-169
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• 2008

The purpose of this paper is to review the major issues of between electronic trade and Ubiquitous computing. The rapidly developed environment by ubiquitous computing make the paradigm form e-trade to u-trade. This Article suggests an a-trade performance framework based on both field and literatures surveys. We propose some research subjects as well as practical implications for improving the performance of global c-trade under ubiquitous.

• 산업기술연구
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• 제9권
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• pp.57-65
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• 1989

Comparative study was conducted on the Human Resouces Management Practices between U.S.A. and Japan with reference to their socio-cultural tradition and environments. Special attention were given to those topics as prevailing value system in both country underlying human and organizational behavior, authority and responsiblility taking manner, inter-personal and social relations within conporate entity and society at large, and finally the pattern of individual involvement to the organization. The results clearly revealed that the sovio-cultural enviornmentsin respective country functions as the major influencing attributes in the formulation of current management practices.

• East Asian mathematical journal
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• 제35권3호
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• pp.319-329
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• 2019

In this paper, we provide sufficient conditions of a pair of weights (u, v) and a function b so that the dyadic paraproduct is bounded from $L^2_u(X)$ into $L^2_v(X)$, where X is a space of homegeneous type. In order to prove the main result we use the honest dyadic system introduced in [10].

• 환경정책연구
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• 제3권2호
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• pp.31-57
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• 2004

Attempts were made to compare and analyze the policies of the United States, the United Kingdom, the Netherlands, Germany and Denmark concerning Korea's major problems associated with legal liability of the contaminated sites. These countries were chosen from a feasible preliminary analysis of 18 countries of the EU and the U. S. The major problems were revealed based on the analysis of Korean legacy and legislation, which are summarized as follows i) lack of clear detailed technical and legal guidance to determine the responsible party or parties of contaminated sites, ii) no distinction between the strict and non strict legal liability of innocent land owners, iii) no clearly set limit on retroactive legal liability. Comparison of the policies of countries chosen suggested improvements regarding these major problems as follows: i) activating national and international research on soil contamination prevention policy, ii) arranging distinct legal regulation between strict and non strict liability criteria, iii) establishing the limits on innocent and non strict liability, iv) establishing methodology and process of legal liability distribution and compensation, and v) establishing a legal process to redeem any benefit derived from remediation of contaminated sites with the public budget. Our policy suggestions above are not yet conclusive due to a lack of policy implementation simulation. Additional research is needed on aspects of social, economic and long term effects of the proposed policy directions. Nevertheless, application of the policy suggestions of this research would increase the efficacy of Korean policy regarding the survey and remediation of the potentially contaminated sites.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.371-379
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• 2010

2005년 교토의정서가 발효되면서 세계는 에너지절감 및 저탄소 수단위주의 대중 교통정책이 펼쳐지고 있다. 우리나라는 현재 세계 8위의 탄소배출국이며 2013년부터는 온실가스 감축의무대상국에 포함될 예정이다. 본 논문에서는 국가교통시설의 투자전략을 고효율 및 저탄소 정책을 달성할 수 있도록 녹색교통수단인 철도를 중심으로 대중교통체계를 개편하기 위해 다양한 추진전략을 제시하였으며 추진전략은 크게 속도, 접근성, 도시개발, 유비쿼터스 측면에서 고려하였다. 본 연구에서 제시한 4가지 주요전략은 1시간철도, Seamless 30, Rail Urbanism, U-Rail 로 정의 하였으며 1시간철도는 1시간대 연결 가능한 고속철도망 구축, Seamless 30은 주요 거점역까지 30분 이내 접근, Rail Urbanism은 철도기반의 도시계획 실현, U-Rail은 Ubiquitous 기반의 철도서비스 제공이라는 목표를 설정하였다. 각 추진전략별 세부추진과제를 수립하여 교통분야의 전문가를 중심으로 AHP 분석을 실시하였으며 각 세부추진과제별 추진 우선순위를 도출하여 단기, 중기, 장기로 구분하여 Action Plan을 제시하였다.

• 한국식품과학회지
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• 제32권5호
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• pp.1149-1157
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• 2000

고추장 변색 요인을 확인하기 위하여 전통적인 방법으로 떡고추장과 식혜고추장을 만들고 가열처리, 포장중 질소치환 및 U.V 조사여부에 따른 변화를 관찰하였다. 각 고추장의 색도 변화는 일반적으로 숙성기간이 경과됨에 따라 L, a, b값은 감소하고 ${\delta}E$ 값은 증가하는 경향을 보였다. 그 중 떡고추장의 ${\delta}E$ 값은 자외선 조사구에서 다른 처리구에 비하여 높았고 식혜고추장의 ${\delta}E$ 값은 비열처리구에서 전반적으로 높게 나타났다. 갈변 요인 분석에서는 떡고추장의 주요 갈변 요인으로는 빛이, 식혜고추장에서는 열처리와 빛이 작용하였으며 각각의 갈변 요인들이 상호 작용함으로 서 고추장의 갈변에 관여함을 확인하였다. 고추장 추출물의 흡광도 변화에서는 고추장을 아세톤으로 추출하여 흡광도를 측정한 결과 $450{\sim}470$ nm에서, 물 추출물의 흡광도는 $200{\sim}205$ nm에서 가장 최고치를 나타내었다.