• Asia pacific journal of information systems
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• 제30권1호
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• pp.21-30
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• 2020

Bitcoin (BTC) is a type of cryptocurrency that supports transaction/payment of virtual money between BTC users without the presence of a central authority or any third party like bank. It uses some cryptographic techniques namely public- and private-keys, digital signature and cryptographic-hash functions, and they are used for making secure transactions and maintaining distributed public ledger called blockchain. In BTC system, each transaction signed by sender is broadcasted over the P2P (Peer-to-Peer) Bitcoin network and a set of such transactions collected over a period is hashed together with the previous block/other values to form a block known as candidate block, where the first block known as genesis-block was created independently. Before a candidate block to be the part of existing blockchain (chaining of blocks), a computation-intensive hard problem needs to be solved. A number of miners try to solve it and a winner earns some BTCs as inspiration. The miners have high computing and hardware resources, and they play key roles in BTC for blockchain formation. This paper mainly analyses the underlying cryptographic techniques, identifies some weaknesses and proposes their enhancements. For these, two modifications of BTC are suggested ― (i) All BTC users must use digital certificates for their authentication and (ii) Winning miner must give signature on the compressed data of a block for authentication of public blocks/blockchain.

• 한국가스학회지
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• 제20권4호
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• pp.33-43
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• 2016

미국과 유럽의 가스회사에서는 배관의 보수방법으로 그라인딩, 육성용접, 슬리브덮개용접, 복합재료보수, 핫태핑, 클램프 등 다양한 방법을 사용하고 있으며, 배관에 손상이 발생한 경우 사용적합성 평가를 거쳐 배관보수를 실시하고 있다. 또한, 미국과 영국 등에서는 매설된 도시가스배관이 타공사 또는 부식으로 인해 손상을 입은 경우 손상형태별로 적용 가능한 배관보수방법을 규정하고 있다. 국내의 경우에는 노후된 중압배관에 대하여 정밀안전진단을 하도록 하고 있으며, 정밀안전진단결과 발생된 결함의 종류 및 정도에 따라 배관을 보수, 교체 또는 신설하도록 규정하고 있다. 그러나 보수 및 보강 방법에 대하여는 기준이 마련되어 있지 않아 배관에 손상이 발생한 경우 주로 손상된 배관을 절단한 후 단관(短管)으로 교체하는 방법만을 사용하고 있다. 본 논문에서는 미국, 영국 등 국외의 보수방법 및 기준을 조사하고, 국내의 매설배관 검사 방법 등에 대해 조사하고, 보수방법 시험 결과를 분석한 후 국내 실정에 맞는 배관보수기준(안)을 제시하였다. 개발되는 기준에 따라 도시가스사업자가 정밀안전진단 결과의 후속조치로 배관보수를 하는 경우 가스공급을 중단하지 않아도 되므로 가스의 안정적 공급에 기여할 수 있을 것으로 판단된다.

• 한국의류산업학회지
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• 제19권3호
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• pp.267-279
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• 2017

The necessity on children dresses for cultural events and emotional aspects in designs have become important according to the development of kids industry and revitalization of party culture, and so grasping emotional requirements of consumers (image perception) is necessary actually. For the purpose of this research, the study used 27 color pictures on the whole bodies of preschool children who wore children dresses that mixed clothing design factors differently (sleeve, skirt length, waist line, materials, color, decoration type and location) through a survey. Regarding the survey objects, this study objected preschool children of 5~6 years old girl's mothers who lived in Gwangju Metropolitan City, and its results were same as follows. First, the mothers evaluated children dresses like 'beautiful,' smart,' 'cute,' 'tidy' images. Second, sleeve, waist line, skirt length, materials, color, decoration type and location appeared to clothing cues affecting influences to overall image perception of children dresses, and decorations were implicated as salient cues that affected greater influences to image perception of children dress wearers than other clothing design factors especially. Based on the research, this study expects that various forthcoming researches have been made continuously, and it could become a guideline for the development of children dress industry afterwards.

• 한국경영과학회지
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• 제22권3호
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• pp.209-222
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• 1997

In this paper, we study a bargaining order problem where one buyer sequentially bargains with two sellers whose reservation prices are unknown to the buyer but correlated. Our main question is who the buyer should bargain first with to maximize his expected payoff. This type of problem is widely applicable to business and political situations where one party negotiates with multiple parties sequentially. One of the most important element in a sequential bargaining is "linkage effect" which exists when the aggreement of the previous bargaining affects the outcome of the following bargaining. To examine "linkage effect", we assume that the sellers'objects are similar so that the sellers' reservation prices are correlated. In addition, to consider incomplete information aspect regarding reservation prices, it is assumed that the sellers' reservation prices are unknown to the buyer. That is, we deal with one sided incomplete information case. In our model, there are two stages in each of which the buyer meets one seller. Since we are concerned with the bargaining order, we consider two different bargaining orders. Using game theory, we find a perfect Bayesian equilibrium and compute the buyer's expected payoff for each bargaining order. Finally we identify the advantageous bargaining order for the buyer by comparing the expected payoffs obtained under two different bargaining orders. Our results are as follows: the advantageous bargaining order depends on the prior probability of the seller type. However, in general, the buyer should bargain first with the seller whose object is less valuable to the buyer. The basic reason for our result is that the buyer wants to experiment in the first stage to find out the sellers' reservation prices and in doing so, to minimize the experimental cost and maximize potential gain in case of negotiation failure in the first stage. in the first stage.

• 가정과삶의질연구
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• 제8권1호
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• pp.69-82
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• 1990

The purposes of this are to figure out the amounts of leisure time of full-time homemakers and to find out leisure time factors contributed to raise the quality of life. The major findings are the followings: 1) Full-time homemakers spend 353 minutes(5.9 hours) on the average per day on the leisure. Time for active leisure(creative activities, sports activities, spectator events, going to the party, and so on) is 70 minutes, while that for passive leisure(watching TV. listening to the radio, reading newspapers. magazines. Books, chating, relaxing, card playing) is 283 minutes(4.7 hours). The passive leisure is the main type of spending leisure time. 2) The total leisure time of wives is significantly related to SES factors. The higher the wives age and education, the family income, and the age of the latest child, the more the wives total leisure time. But the more the family numbers, and the child numbers, the lower the leisure time. Active leisure time is highly rela ed to family income, while passive leisure time is considerably family composition. 3) The wives are mostly satisfied with their lives. The wives perceptions of the quality of life is related to wives's education, house type, and family income. 4) The wives total leisure time is not related to the quality of life. There is a positive correlation between active leisure time and the quality of life, while a negative relationship is between passive leisure time and the perception of the quality of life. 5) In analysis of causal model, it appears that family income and active leisure time of wives directly affect the perceived quality of life. The more the family income and active leisure time, the higher the quality of life. it is implicated for wives to take and active attitude and to reduce, if possible, passive leisure time and to increase active leisure time.

• 한국의류산업학회지
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• 제17권1호
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• pp.53-63
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• 2015

The necessity on children dresses for cultural events and emotional aspects in designs have become important according to the development of kids industry and revitalization of party culture, and so grasping emotional requirements of consumers is necessary actually. This study aims at purpose of this research, the study used 27 color pictures on the whole bodies of children who wore children dresses that mixed clothing design factors differently (sleeve, skirt length, waist line, materials, color, decoration type and location) through a survey. Regarding the survey objects, this study objected children of 5~6 years old in full and their mothers who lived in Gwangju Metropolitan City, and its results were same as follows. First, dress preferences between children group and mother group were similar generally, but differences were displayed from dress lengths. That is, children preferred long length in general, and whereas mothers were come out to prefer shot length comparatively. Second, the study could get results by mixing ranking 1 and ranking 2 according to clothing design factors that were preferred by children group and mothers group deduced through an empirical analysis. Merely, the location according to decoration type was limited to ranking 1. Based on the research, this study expects that various forthcoming researches have been made continuously, and it could become a guideline for the development of children dress industry afterwards.

• 융합보안논문지
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• 제16권6_1호
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• pp.25-32
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• 2016

비대칭전은 상대방이 효과적으로 대응할 수 없도록 상대방과 다른 성격 및 기능을 가진 수단과 방법으로 수행하는 작전이며 '이질성'과 '우월성'을 원칙으로 한다. 여기서 '이질성'이라 함은 적이 보유하고 있지 않거나 개발하지 못한 무기체계를 운용하여 적의 취약분야를 공격하거나 적의 능력을 파괴하는 것이며, '우월성'은 적보다 양적 질적 측면에서 압도하는 능력으로 대응하는 것이다. 비대칭 전략의 유형은 복잡하기 때문에 다양한 비대칭 전략의 유형분류가 가능하다. 따라서 비대칭전에 대한 여러 측면에서의 이해가 요구된다. 비대칭전의 관점에서 본다면, 고대전투에서 현대전에 이르기까지 혁신적인 방법과 전략 전술로 적을 격멸한 사례들은 비대칭전의 사례로 볼 수 있다. 전투에서 승리한 핵심요인에는 비대칭 전략 및 수단의 차별적 우월성이 반드시 존재했고 앞으로도 이러한 현상은 지속될 것이다. 한 때 창출된 비대칭은 시간이 경과함에 따라 상대편이 모방적으로 적응하여 비대칭이 소멸된다. 현대전에서 전략적 전술적 비대칭의 우위를 확보하려면 새로운 비대칭 전에 대하여 연구하고 상대방의 전략과 전술에 대응하는 방책개발을 계속해야 한다.

• Journal of Korea Trade
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• 제23권6호
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• pp.14-32
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• 2019

Purpose - This study is designed to provide new insights on trade claim management by typifying trade claims from a relational perspective, which defines trade as an organic combination that exchanges relationships based on a mutual goal instead of conflicts between obligations and rights of the contracting parties. Design/methodology - This is a phenomenological study that aims to typify trade claims based on a relational perspective and extract implications for trade claim management. The research procedures of this study are as follows. First, international commercial dispute cases applying the CISG are collected. Second, the cases collected are quantified through content analysis. The variables for quantification are developed based on a relationship perspective. Third, cluster analysis is conducted on coded data to typify cases. And finally, this study compares the characteristics of each type using analysis of variance and suggests implications for the strategic management of trade claims from a relational perspective. Findings - Results show that trade claims are divided into four clusters, depending on whether flexibility is accepted or not and which party violates mutuality. There is also a difference between the claimant and the cause of the claim, according to the cluster. Based on the results, this study suggests that the buyer and the seller should employ different strategies depending on the type of trade claim and presents proposals for strategic claim management. Originality/value - Firstly, this study extends the theoretical discussion on trade claims by applying relational contract theory. Prior studies on trade claims have been primarily based on traditional contract theory. The second is to analyze trade claims quantitatively. Prior case studies on trade claims have mainly relied on qualitative research. Finally, the study contributes to international commercial practice by typifying trade claims and presenting options for strategic management.

• 한국정보통신학회논문지
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• 제22권11호
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• pp.1531-1537
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• 2018

해운 물류에서 대량의 컨테이너는 선박, 트럭, 철도 등 복합 운송의 형태로 항만을 거쳐 목적지로 이동된다. 선사, 화주와 같은 물류 주체는 화물의 주요 물류 거점에 대한 실시간 반 출입 정보를 필요로 한다. 특히 항만은 해운과 내륙을 연결하는 중요한 공간으로써 물류 주체의 관심이 높다. 본 논문에서는 GPS를 이용한 위치 추적을 점 단위가 아닌 면 단위를 기반으로 동적으로 나타낸다. 즉 어느 항만의 영역 안으로 들어가는지, 나가는지, 또는 통과하는지와 같은 동적인 위치 추적을 나타내고 있다. 이전 연구의 위치 추적 알고리즘을 기반으로 능동형(Active) IP-RFID 기술을 활용한 항만 진출입, 항만 내부에서의 실시간 위치 추적 알고리즘을 제안한다.

• 한국항공우주학회지
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• 제45권4호
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• pp.269-275
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• 2017

전투기 형태의 항공기는 외부 장착물의 중량, 공력 특성 및 조합 형태에 따라 공력탄성학적 특성에 상당한 영향을 받게 된다. 따라서 항공기를 운용하기에 앞서 기본적으로 모든 외부 장착물 조합에 대한 공력탄성학적 안정성이 반드시 검증되어야 한다. 그러나 공력탄성학적 안정성을 분석하기 위해서는 항공기의 구조, 중량, 조종면 특성, 외부형상 등과 같은 설계 데이터가 필요함에 따라, 원칙적으로 항공기 플랫폼을 개발한 제작사 이외에는 적합성 입증을 수행하는데 상당한 제한이 따를 수밖에 없다. 그럼에도 불구하고 작전환경의 변화 및 항전기술의 발전으로 인해 원 제작사의 지원 없이 항공기를 운용하는 국가 또는 기관에서 자체적으로 신규 장착물을 장착해야 하는 상황이 있을 수 있다. 본 논문에서는 이와 같이 설계 데이터를 갖고 있지 않은 도입 항공기에 대해 신규 장착물을 장착하는데 필요한 공력탄성학적 적합성 입증 방안에 대해 기술하였다.