• 인터넷정보학회논문지
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• 제21권1호
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• pp.17-31
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• 2020

블록체인 기술이 급속도로 발전하고 있음에 따라 금융·물류 등 다양한 분야에서 블록체인 기술을 실용화하려는 시도들이 진행되고 있으며, 데이터 무결성이 매우 중요한 공공분야 또한 마찬가지이다. 국방분야 또한 네트워크 중심 작전환경(NCOE) 하에 작전운영을 위해서는 지휘통신 네트워크의 보안성 강화 및 완전무결성 확보가 매우 중요하다. 이를 위해 블록체인 네트워크를 적용한 지휘통신네트워크 구축이 필요하나, 현재까지의 블록체인 기술은 51% 공격 등의 보안 이슈들을 해결하지 못하고 있어, 국방에 접목하기 어려운 것이 현실이다. 특히, 현재 블록체인에서 많이 사용되고 있는 Practical Byzantine fault tolerance (PBFT)알고리즘은, 악의적인 행동을 하는 노드들에게 penalty 요소가 없고, 합의를 방해하는 노드가 전체 노드의 33%이상만 차지해도 합의 실패를 만드는 문제점이 있다. 본 논문에서는 블록체인의 주요 합의 알고리즘인 PBFT의 보안성 향상을 위해, Trust 모델을 접목하여 비정상 행위에 대한 penalty 메커니즘이 적용된 Adaptive Consensus Bound PBFT (ACB-PBFT) 합의 알고리즘을 제안한다.

• 한국정보전자통신기술학회논문지
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• 제15권6호
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• pp.440-448
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• 2022

최근 분산 에너지 자원들의 도입으로 전력망의 최적 자원 할당 문제의 중요성이 강조되고 있고, 대규모 전력망의 방대한 양의 데이터를 처리하기 위해 분산 자원 할당 기법이 요구되고 있다. 최적 자원 할당 문제에서 각 발전기의 발전 용량의 한계로 인하여 수급의 균형이 만족하는 경우를 고려한 연구는 많이 진행되고 있지만, 총 요구량이 최대 발전 용량을 초과하는 경우인 수급 불균형을 고려한 연구는 아직 미미한 실정이다. 본 논문에서는 수급 균형인 상황뿐만 아니라 수급 불균형 상황을 고려하여 전력망의 최적 자원 할당을 위한 일치 기반의 분산 알고리즘을 제안한다. 제안하는 분산 알고리즘은 수급 균형을 만족하는 경우에는 최적의 자원을 할당하고, 수급이 불균형한 경우에는 부족한 자원의 양을 계측할 수 있도록 설계하였다. 마지막으로 모의실험을 통하여 제안된 알고리즘의 성능을 검증하였다.

• 융합신호처리학회논문지
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• 제24권2호
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• pp.103-111
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• 2023

일치기법은 이웃한 개체 간의 정보교환을 통하여 개체들의 상태를 동일한 상태로 수렴시키는 것이 목적이며 다개체 시스템의 제어를 위해 많은 연구가 진행되고 있다. 실제 시스템에서는 각 개체의 측정 변수가 서로 다르거나 통신상의 정보 손실이 발생할 수 있고, 통신상의 안정성을 위하여 각 상태에 대한 서로 다른 네트워크를 구성해야 할 수 있다. 또한, 시스템에 존재하는 입력 포화 및 외란으로 인하여 그룹의 불안정성을 야기할 수도 있다. 따라서 본 논문에서는 이종 상태 정보와 입력 포화 및 외란을 고려하여 다개체 시스템의 군집을 위한 PID(Proportional-Integral-Derivative) 기반의 일치 제어 기술을 연구한다. 구체적으로 2차 시스템으로 모델링된 다중 추종 개체들과 단일 리더 개체를 고려하였고, 오차 시스템의 안정성 판별을 통하여 일치를 달성하기 위한 조건을 분석하였다. 제안된 알고리즘은 위치 그래프의 연결성만 보장된다면 일치를 달성할 수 있음을 확인하였고, 일치 알고리즘을 확장하여 다개체 시스템에 대한 편대 제어 문제를 연구하였다. 마지막으로 모의실험을 통하여 제안된 알고리즘의 유효성을 검증하였다.

• 로봇학회논문지
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• 제10권3호
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• pp.133-138
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• 2015

This paper presents a modified task structure of coupled-constraints consensus based bundle algorithm especially to resolve the cooperative transportation problem. The cooperative transportation mission has various types of constraints. A modified framework to generate activities and subtasks to solve time and task constraints of the transportation mission by using coupled-constraints consensus based bundle algorithm is suggested. In this paper modifications on task structure, reward function and arrival time calculation are suggested to handle the constraints of cooperative transportation mission.

• 한국빅데이터학회지
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• 제7권1호
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• pp.1-14
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• 2022

대부분의 블록체인이 사용하는 작업증명 합의 알고리즘은 채굴이라는 형태로 대규모의 컴퓨팅리소스 낭비를 초래하고 있다. 작업증명의 컴퓨팅리소스 낭비를 줄이기 위해 유용한 작업증명 합의 알고리즘이 연구 되었으나 여전히 블록 생성 시 리소스 낭비와 채굴의 중앙화 문제가 존재한다. 본 논문에서는 블록생성을 위한 상대적으로 비효율적인 연산 과정을 분산 인공지능 모델 학습으로 대체하여 블록생성 시 리소스 낭비문제를 해결하였다. 또한 학습 과정에 참여한 노드들에게 공평한 보상을 제공함으로써 컴퓨팅파워가 약한 노드의 참여 동기를 부여했고, 기존 중앙 집중 인공지능 학습 방식에 근사한 성능은 유지하였다. 제안된 방법론의 타당성을 보이기 위해 분산 인공지능 학습이 가능한 블록체인 네트워크를 구현하여 리소스 검증을 통한 보상 분배를 실험 하였고, 기존 중앙 학습 방식과 블록체인 분산 인공지능 학습 방식의 결과를 비교하였다. 또한 향후 연구로 블록체인 메인넷과 인공지능 모델 확장 시 발생 할 수 있는 문제점과 개발 방향성을 제시함으로서 논문을 마무리 하였다.

• 분석과 대안
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• 제6권1호
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• pp.163-194
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• 2022

A transboundary environmental problem refers to an environmental problem that goes beyond a country's territory and damages neighboring countries. It is a difficult problem because, basically, it is a natural, rather than intentional, effect, and it is extremely hard to make a scientific consensus on the cause-effect relations between upstream and downstream nations. Air pollution, especially PM 2.5 and PM 10, is one of the typical cases of transboundary environmental problems in the Northeast Asia. This paper analyzes the constraints of environmental cooperation between China and South Korea to address transboundary air pollution issue. It argues that lack of trust and ideological hostility, rather than, scientific uncertainty, is the biggest obstacle for effective cooperation, and these hostile discourses and ideas are mostly generated by media in the downstream nation, the South Korea. In order to identify how South Korean media frames this issue, this paper searched newspaper articles in the six representative South Korean newspapers during the period of 2014 and 2020, and analyzed about 2,000 articles selected. It finds that South Korean media has framed the transboundary air pollution as a China bashing and related domestic political cleavage issue, while it neglects to show the cooperation attempts that the two countries have made to date. Also, while the media focuses on China hate frame, it has never reported the Chinese government's domestic policies to reduce air pollution and their results. Media's overuse of hate and blame frames not only has disrupted trust building but also it will delay a possible turning point of environmental cooperation between the two countries in the future.

• 한국컴퓨터정보학회논문지
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• 제20권10호
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• pp.61-68
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• 2015

This paper deals with the pre-marshalling problem that the containers of container yard at container terminal are relocated in consensus sequence of loading schedule of container vessel. This problem is essential to improvement of competitive power of terminal. This problem has to relocate the all of containers in a bay with minimum number of movement. There are various algorithms such as metaheuristic as genetic algorithm and heuristic algorithm in order to find the solution of this problem. Nevertheless, there is no unique general algorithm that is suitable for various many data. And the main drawback of metaheuristic methods are not the solution finding rule but can be find the approximated solution with many random trials and by coincidence. This paper can be obtain the solution with O(m) time complexity that this problem deals with bin packing problem for m stack bins with descending order of take out ranking. For various experimental data, the proposed algorithm can be obtain the optimal solutions for all of data. And to conclude, this algorithm can be show that most simple and general algorithm with simple optimal solution finding rule.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
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• pp.1142-1149
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• 2003

Various organizational factors effect successful implementation of IT enabled business transformation. Among them, the most critical success factor is deemed to overcoming change management problem. Lots of studies have been made on Implementation methodologies and business process formalizations to encourage organizational members to accept new business process changes. However, the logic or process redesign still depends on qualitative problem solving techniques mostly depending on basically human intuition such as brainstorming. cause-and-effect analysis. and so on. In this paper, we focused on developing analytic framework to design to-be business process structure. which can complement qualitative problem solving procedures. With effective use of IT as an enabler, we provide algorithmic framework applicable to designing various business process changes such as process automation, business process resequencing, and more radical process integration. The framework follows dynamic programming approach in the literature, which is based on the decision making paradigm of organizations to abstract business processes as quantitative decision models. As such, our research ran fill the gap of limited development of theory based analytic methodologies for business process design, by providing objective rationale to reach the consensus among the organizational members including senior management.

• 한국실내디자인학회논문집
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• 제22권3호
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• pp.154-163
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• 2013

Current principles of designating a smoking area within a non-smoking area rely on mere compartmentalization. This causes non-smokers aversion against smokers and smokers complaints about anti-smoking policies, which means both of them are not satisfied with the current scheme. In addition, such a system, far from the original intent of the law, does not provide appropriate respect for people's rights. The biggest problem of the current scheme is that smoking areas are not separated from non-smoking areas. Japan has continued installing independent smoking areas since 2002 and witnessed a decrease in the smoking rate. The country's success is attributable to: the state's active intervention in connection with enterprises; continuous environmental improvements and creation of goods; 'smoking etiquette' campaigns; and the sociality and group consciousness of Japanese people. It is recognized that the synergy of the designation of independent smoking areas and such multi-faceted efforts has led to the nation's accomplishment. Hence, it is required to install independent smoking areas in non-smoking areas in Seoul in order to respect the rights of smokers and non-smokers and resolve conflicts between them. It is not suitable to merely model after Japan's case, however, studies and guidelines that are tailored to Korea's own environment and social atmosphere are required. To ensure that the people recognize the necessity for smoking areas, a social consensus is formed and proper smoking areas are established in a systemic manner, a system for that purpose should connote a symbol of the social consensus and consequent guidelines should take physical elements, human activities and semantic assignment into consideration. This study aims to present basic guidelines to install separated smoking areas, which will keep distance between smokers and non-smokers, form a social consensus and establish a sound smoking culture. These would ensure that the rights of both smokers and non-smokers are fully respected and that government policies are trusted by the people.

• Nuclear Engineering and Technology
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• 제48권1호
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• pp.144-152
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• 2016

Human capabilities, such as technical/nontechnical skills, have begun to be recognized as crucial factors for nuclear safety. One of the most common ways to improve human capabilities in general is training. The nuclear industry has constantly developed and used training as a tool to increase plant efficiency and safety. An integrated training framework was suggested for one of those efforts, especially during simulation training sessions of nuclear power plant operation teams. The developed training evaluation methods are based on measuring the levels of situation awareness of teams in terms of the level of shared confidence and consensus as well as the accuracy of team situation awareness. Verification of the developed methods was conducted by analyzing the training data of real nuclear power plant operation teams. The teams that achieved higher level of shared confidence showed better performance in solving problem situations when coupled with high consensus index values. The accuracy of nuclear power plant operation teams' situation awareness was approximately the same or showed a similar trend as that of senior reactor operators' situation awareness calculated by a situation awareness accuracy index (SAAI). Teams that had higher SAAI values performed better and faster than those that had lower SAAI values.