• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.309-312
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• 2009

The various hazards should be eliminated before operations for the successful launches or tests. Using the contaminated propellants is one of the causes for the launch and test failures. Especially, the systems using liquid oxygen as an oxidizer have risks about fires and explosions not be forecasted if they are contaminated by oil, water and mechanical impurities. The procedure for the quality control of the liquid oxygen and the liquid oxygen filling system and the lessons learned from the first launch preparation with the system are introduced on this paper.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.781-783
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• 2011

The oxidizer filling system, ground facility of the launch complex, should accept difficult requirements from the launcher sufficiently. The launcher do not have unnecessary insulators for mass reduction and manages liquid oxygen mass fastidiously to satisfy the mission requirement. So, the ground facility should be able to accept its requirements, then we should make the operating process being adjusted. In this paper, the operating process design and verification results on the oxidizer filling ground facility for liquid rocket is demonstrated.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.551-554
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• 2012

KARI is now developing KSLV-II which can insert 1.5ton satellite into the orbit, and system design review is close at hand. As a part of mission assurance for space launch vehicle, reliability and safety management is being performed and to assure the safety, KARI has been doing actions on the basis of the safety assurance plan and system safety program plan. In this study, preliminary hazard analysis is reviewed and the result for the propulsion system will be illustrated. The result will be used as a reference for the safety and risk management.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.9
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• pp.2063-2072
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• 2013

Smart Grid is the next-generation intelligent power grid that maximizes energy efficiency with the convergence of IT technologies and the existing power grid. It enables consumers to check power rates in real time for active power consumption. It also enables suppliers to measure their expected power generation load, which stabilizes the operation of the power system. However, there are high possibility that various kinds of security threats such as data exposure, data theft, and privacy invasion may occur in interactive communication with intelligent devices. Therefore, to establish a secure environment for responding to such security threat with the smart grid, the key management technique, which is the core of the development of a security mechanism, is required. Using a hash chain, this paper suggests a group key management mechanism that is efficiently applicable to the smart grid environment with its hierarchical structure, and analyzes the security and efficiency of the suggested group key management framework.

• Knowledge Management Research
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• v.22 no.2
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• pp.119-144
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• 2021

Recently, as competition in the market evolves from the competition among companies to the competition among their supply chains, companies are struggling to enhance their supply chain management (hereinafter SCM). In particular, as blockchain technology with various technical advantages is combined with SCM, a lot of domestic manufacturing and distribution companies are considering the adoption of blockchain-oriented SCM (BOSCM) services today. Thus, it is an important academic topic to examine the factors affecting the use of blockchain-oriented SCM. However, most prior studies on blockchain and SCMs have designed their research models based on Technology Acceptance Model (TAM) or the Unified Theory of Acceptance and Use of Technology (UTAUT), which are suitable for explaining individual's acceptance of information technology rather than companies'. Under this background, this study presents a novel model of blockchain-oriented SCM acceptance model based on the Technology-Organization-Environment (TOE) framework to consider companies as the unit of analysis. In addition, Value-based Adoption Model (VAM) is applied to the research model in order to consider the benefits and the sacrifices caused by a new information system comprehensively. To validate the proposed research model, a survey of 126 companies were collected. Among them, by applying PLS-SEM (Partial Least Squares Structural Equation Modeling) with data of 122 companies, the research model was verified. As a result, 'business innovation', 'tracking and tracing', 'security enhancement' and 'cost' from technology viewpoint are found to significantly affect 'perceived value', which in turn affects 'intention to use blockchain-oriented SCM'. Also, 'organization readiness' is found to affect 'intention to use' with statistical significance. However, it is found that 'complexity' and 'regulation environment' have little impact on 'perceived value' and 'intention to use', respectively. It is expected that the findings of this study contribute to preparing practical and policy alternatives for facilitating blockchain-oriented SCM adoption in Korean firms.

• The Journal of Bigdata
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• v.4 no.1
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• pp.1-10
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• 2019

As FTA is spreading, it is becoming more and more necessary to improve the accuracy and reliability of the country of origin information at the domestic trading stage in preparation for the actual surveys expected to surge in the near future. However, there are many problems in collecting and managing information related to origin. It is pointed out that the shortage of export-oriented profits and the incentive for issuance of FTA-related profits, as well as the lack of information on the distribution and management of origin information of domestic manufacturing companies are also pointed out as important causes. In this paper, we propose a method to improve the efficiency of management and circulation of smooth FTA origin (comprehensive) certificate of Korean companies and to improve reliability through manipulation prevention by building prototype of origin information management system based on private block chain Hyperledger. The block chain, called Distributed Ledger or Trusted Internet, provides a technical infrastructure that enables various related companies to distribute origin information with high reliability and immediate distribution in the supply chain, but research on its application is still in the beginning stage.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04b
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• pp.403-405
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• 2002

다양한 제품요구와 짧아진 제품의 수명주기, 수시로 발생하는 주문과 품목의 변화등으로 기업은 공급체인관리(SCM)를 도입하고 있으나 빈번한 이산사천의 발생으로 계획부분과 제조현장 실행부분의 차이가 발생하고 있다. 본 논문에서는 이러한 문제를 해결하기 위하여, 실행부분에서 발생하는 이산사건의 관리를 통해 계획부분과 실행부분의 차이를 줄이는 에이전트 기반 이산사건 관리모델을 제안하였다. 이산사건에 대해서는 컬러드 페트리 넷을 이용하여 명세하였고 관리모델은 에이젼트를 기반으로 지능적이고 자율적인 특성을 이용하여 사건의 발생에서 분류 지식데이터베이스구축, 전송에 이르는 이산사건 관리모델 아키텍쳐를 제시하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.159-165
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• 2020

The demand for food safety has emerged as a major social issue due to changes in diet patterns and consumers' perceptions, along with the advancements in society and the development of the food industry. Consumers are demanding more information about the food they consume, and are sensitive to food scandals. With such interest in food safety, blockchain technology is attracting attention as a means of effectively responding to poor food management resulting in food fraud or unsafe distribution. By ensuring the accuracy of, and trust in, traceability in the food supply chain, it is possible to build trust between traders and to ensure safe food distribution. This paper proposes a next-generation agri-food distribution system that can provide and manage (for suppliers, consumers, and distribution officials) a variety of agri-food information, such as the history, distribution, safety, quality, and freshness of food. Information on product status and distribution status in all processes, including production, processing, distribution, sales, and consumption, can be monitored and controlled in real time (anytime, anywhere), and users can check the safety level of each type of food in real time through an app.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.331-331
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• 2020

급격한 산업화와 도시화로 인한 도시유역의 불투수면의 증가와 이에 따른 배수능력의 저하로 인해 도시 물순환의 왜곡이 발생하였다. 따라서 과거 도시 물관리 기법의 한계가 나타났으며 이를 위해 저영향개발 기법 등과 같은 도시 물관리 기법의 패러다임이 변화하였다. 본 연구에서는 저영향개발 기법에서 도시유역 내 활용이 유용한 침투형 시설 중 투수블럭에 대한 물순환 성능평가를 실외실험을 통해 분석하였다. 성능평가 실험은 부산대학교 양산캠퍼스 한국 GI&LID 센터 내 투수블록 뿐만 아니라 블록 하부 골재층까지 설치가 가능하도록 되어있어 실제 현장과 유사한 환경을 구축이 가능한 2.4×10.9×0.4 (m) 규모의 주차장형 LID 실증시험시설을 활용하였다. 인공강우 분사를 위한 실외 인공강우모사 장치 크기는 2×2(m)으로 본 시험을 위하여 5개의 인공강우모사 장치를 연결하여 활용하였으며, 본 시험장치는 강우를 공급하기 위한 수조와 펌프, 일정한 유량을 유입하기 위한 유량계, 강우를 분사하기 위한 노즐, 인공강우가 실제 강우와 같이 자유낙하 하도록 구현하기 위한 오실레이터 등으로 구성되었다. 시험대상인 틈새투수블록은 석재블록 규격 400×600×100 mm이며 재질은 받침안정층(흙), 투수블록(화강석)으로 구성되어 있다. 실험의 시나리오는 시험체에 강우강도 30mm/hr, 50mm/hr, 100mm/hr에 해당하는 양을 1시간 동안 유입하여 시험 시작 후, 강우지속시간, 표면유출지속시간, 표면유출량을 1분 단위로 측정. 시험체에 유공관이 설치된 경우에는 침투유출지속시간, 침투유출량도 함께 1분 단위로 측정하였으며 각 강우강도별로 측정하고, 1회 측정 후, 각 시험별 시험 대상체의 조건을 같게 하기 위한(하부 지반의 건조) 약 3일 이후(상황에 따라 변동 가능) 시험하였다. 본 실험의 결과, 강우강도가 30 mm/hr와 50 mm/hr인 경우에는 화강석 틈새투수블록포장에서 지표 유출이 발생하지 않았으며, 강우강도 100 mm/hr의 경우 260 L의 지표 유출이 발생하여, 불투수표면 대비 84%의 지표유출 저감률을 보여줌으로서 투수블럭에 물순환 성능에 대한 효과를 분석하였다.

• Information and Communications Magazine
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• v.24 no.9
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• pp.60-66
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• 2007

이동통신서비스의 증가와 관련 산업의 비약적인 발달은 필연적으로 그 매개체인 이동통신사업용주파수 수요의 폭발적인 증가를 가져왔는데 현재의 주파수배분표는 그 공급이 매우 제한적임을 보여주고 있다. 이러한 변화에 발맞추어 전파관리의 패러다임도 바뀔 수밖에 없는데 기존의 국가관리체제에는 변함이 없을 것이나 이미 할당받은 주파수이 이용을 활성화하기 위하여는 시장 기반의 거래로 그 관리철학이 바뀌어야 한다. 그 제도적 뒷받침을 위하여는 우선 주파수할당시의 용도와 기술기준을 주무부처가 일일이 지정해야 하는가에 대한 근본적인 검토가 필요하고 주파수 양도 임대시 정보통신부장관의 승인제도는 그 법문에 맞게 최소한의 것에 행사되어야 한다. 이는 배분된 주파수대역에서의 주파수이용기술의 발전을 민간레벨에서 촉진시킨다는 의미에서도 매우 중요한 것이다. 더불어 주파수 할당을 비롯하여 전파자원의 분배는 행정절차법이 정한 그 것에 따라야 하며, 나아가 일정한 전파자원의 분배는 관리주체인 정보통신부가 아닌 제3의 독립기관이나 국회의 소관사항으로 하는 것이 바람직하다.