• 한국정보통신학회논문지
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• 제14권6호
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• pp.1453-1459
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• 2010

최근 들어 단순 보관의 기능만을 가지고 있던 기존의 냉동창고가 보관뿐만 아니라, 규격화된 유통 시스템을 갖추어 전체 물류 공급망 관리의 효율성과 경쟁력을 갖추고자 한다. 이를 위해 라디오 주파수를 이용하여 움직이는 물체를 인식, 추적, 분류할 수 있는 기술인 RFID (Radio Frequency Identification)를 적용할 수 있다. 본 논문에서는 RFID 기술을 적용하여 최적화된 비즈니스 프로세스를 지원하는 냉동창고 관리 시스템을 개발하고자 한다. 이를 위해 냉동창고 업무 프로세스를 분석하고 RFID 기술 도입에 따른 의사결정이 필요한 설계요소들을 식별한다. 식별된 설계요소들은 RFID 배치 시뮬레이터를 이용하여 RFID 데이터가 비즈니스 프로세스에 통합되는 과정에 대하여 그 효율성을 판단할 수 있게 한다.

• 예술인문사회 융합 멀티미디어 논문지
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• 제8권11호
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• pp.215-222
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• 2018

본 논문에서는 슈퍼커패시터를 적용한 에너지 저장장치에 대해서 연구하였다. 납축전지등을 사용하였던 기존방식과는 다르게 슈퍼커패시터를 사용하여 고출력을 달성할 수 있으며, 이러한 특징으로 인하여 연구된 저장장치는 비상전원용 전력을 공급할 수 있을 뿐만 아니라, 전력품질 개선이나 짧은 순간에 큰 출력을 요구하는 고속 기동용 모터등의 전원시스템으로도 사용이 가능한 장점이 있다. 에너지변환 시스템은 양방향 인버터와 컨버터로 구성되어 고속, 고출력의 충전, 방전을 수행할 수 있는 장점도 있다. 양방향 인버터를 이용한 two loop 제어기 설계 방법이 제시되었고, 실험과 제작을 통해 설계 방법의 정합성을 입증하였다. 설계 순서는 먼저 상태공간 평균화 기법과 Decoupling 기법을 이용하여 선형화된 전달함수를 계산하였다. 다음 20% 오버슈트와 안정시간을 만족시키는 전류 제어기 설계를 한 후에 오버슈트 없는 전압과 10배 이상 느린 안정시간을 가지는 전압제어기를 설계한 후 단위계단응답 커브를 통해 원하는 설계특성이 나오는 지를 확인하는 과정으로 이루어진다. 설계된 제어기들은 계통과 단위 역률을 이루며 제어되기 때문에 전력품질 향상을 이룰 수 있으며, 빠른 응답특성과 정상상태 오차를 0으로 만들 수 있는 우수한 제어특성을 가지고 있음을 확인할 수 있었다.

• 서비스연구
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• 제10권2호
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• pp.31-42
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• 2020

본 연구는 수출기반활용사업 중에서 디자인서비스 분야의 성과에 관한 연구이다. 특히, 참여기업 관점에서 디자인서비스의 이용실태와 이에 따른 문제점을 파악하여, 관련 사업에서 디자인서비스 분야에 있어서 성공적 지원방안 마련을 위한 기초 자료 제공을 목적으로 한다. 본 연구는 기록자료(archival records)를 활용하여 디자인서비스의 정확한 성과를 측정할 수 있도록 정량적 설문(survey) 조사를 설계하였고, 설문은 총 3차례 발송을 통하여 참여기업은 135개사에서 응답하였다. 연구결과에서 디자인서비스의 유의미한 성과는 의료/바이오/헬스케어, 전기/전자제품 등 국가 주력산업군의 수출에서 디자인 역할이 중요하다는 것을 알 수 있었다. 또한, 매출액 차이와는 상관없이 모든 참여기업들이 디자인서비스를 이용하고 있다는 것을 알 수 있었다. 특히, 디자인서비스 효과는 참여기업들의 96 %가 가장 효과적이었던 서비스라고 답변하였다. 결과적으로 수출지원기반활용사업에 있어서 디자인서비스의 중요성을 입증하였고, 향후 수출지원기반활용사업의 디자인서비스의 발전방향으로서 관리 시스템 도입의 중요성을 제언하였다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제9권4호
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• pp.216-224
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• 2009

The endless scaling down of the semiconductor process made the impact of the power network noise on the performance of the state-of-the-art chip a serious design problem. This paper compares the performances of two popular circuit reduction approaches used to improve the efficiency of power network noise analysis: moment matching-based model order reduction (MOR) and node elimination-based MOR. As the benchmarks, we chose PRIMA and R2Power as the matching-based MOR and the node elimination-based MOR. Experimental results indicate that the accuracy, efficiency, and memory requirement of both methods very strongly depend on the structure of the given circuit, i.e., numbers of the nodes and sources, and the number of moments to preserve for PRIMA. PRIMA has higher accuracy in general, while the error of R2Power is also in the acceptable range. On the other hand, PRIMA has the higher efficiency than R2Power, only when the numbers of nodes and sources are small enough. Otherwise, R2Power clearly outperforms PRIMA in efficiency. In the memory requirement, the memory size of PRIMA increases very quickly as the numbers of nodes, sources, and preserved moments increase.

• 농촌계획
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• 제11권1호
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• pp.25-33
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• 2005

This study conducted a comparative analysis on ordinances on landscape composition by local governments, which are a part of the policy to activate landscape composition, by examining the cases of Korea and Japan. For the purpose of specialized landscape compositions according to the own characteristics of Korean local governments, this study suggests factors to consider on the enactment of ordinance on landscape composition as follows. First, in order to compose landscape with an unique figure of the local government, it is required to collect and analyze informations about the local landscape, to provide consistent programs of education and publicity related to the landscape composition and to encourage the involvement of local citizens and reward it. Second, the construction of the ordinance needs to build a plan of landscape composition for each district focused on the landscape composition, to introduce a system which enables self-designation of an ordinance, to establish a detailed guidance, to assign the duty to keep the guidance and regulate punishment in case of a violation of the guidance. It could be done by completing the common or basic elements on the construction of the ordinance on landscape composition.

• 대한산업공학회지
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• 제42권3호
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• pp.182-197
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• 2016

One of the distinctive characteristics of industrial engineering (IE) is its multidisciplinarity. This paper explores the multidisciplinary nature of IE using journal citation network analysis. Using the relatedness indexes of IE journals obtained from journal citation report (JCR), we firstly construct the IE network only composed of 26 IE journals. The resulting IE network is partitioned into three sub-networks: management engineering, manufacturing/quality, and ergonomics. We then propose the IE convergence network which includes 81 related journals in other disciplines as well as 26 IE journals. Scrutinizing the IE convergence network reveals that IE has a high degree of interactions with seven disciplines : Operations Research and Management Science, Statistics and Probability, Manufacturing Engineering, Computer Science, Engineering Design, Business Management, Human Factors and Ergonomics. We investigate the contributions of the related disciplines to IE as well as contributions of IE to the related disciplines. The role of IE journals in exchanging knowledge with related disciplines is also identified by brokerage analysis. It is shown that visualizing and analyzing the IE convergence network can provide an excellent overview of the multidisciplinary structure of IE, which can help IE researchers easily grasp the state-of-the art of IE research.

• Steel and Composite Structures
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• 제20권1호
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• pp.21-41
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• 2016

Cold-formed steel structures are increasingly attractive due to their benefits of good mechanical performance and constructional advantages. However, this type of construction is still not fully exploited as a result of the acknowledged difficulties involved in forming construction-efficient and cost-effective connections. Furthermore, there is a lack of information on the structural behavior of the cold-formed steel connections. In this study, the research on various cold-formed steel connections was comprehensively reviewed from both fundamental and structural points of view, based on the available experimental and analytical data. It reveals that the current design codes and guidelines for cold-formed steel connections tend to focus more on the individual bearing capacity of the fasteners rather than the overall structural behavior of the connections. Significant future work remains to be conducted on the structural performance of cold-formed steel connection. In addition, extensive previous research has been carried out to propose and evaluate an economical and efficient connection system that is obtained from the conventional connecting techniques used in the hot-rolled industry. These connecting techniques may not be suitable, however, as they have been adopted from hot-rolled steel portal frames due to the thinness of the sheet in cold-formed steels. The review demonstrates that with the increasing demand for cold-formed steel constructions throughout the world, it is crucial to develop an efficient connection system that can be prefabricated and easily assembled on site.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.683-686
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• 2000

The chargers for DC power supply of the contro1lers, which have been installed in the relay rooms in 345/154kV substations of KEPCO, lag in both aspects of technique and performance. Moreover, as they are SCR-based, they dont meet the performance requirements of todays digital and automated controllers. Now two controllers are running in pair and one of those is for reservation. There are lots of troubles because the patrol engineering team has to replace them manually whenever they are out of order. So it is expected to bring convenience if the charger replacement is automated. Also, the existing chargers take much space, weight and cost - which have increased the need of development to make them smaller, less expensive, and have high quality. We will develop a charger system which has one fifth of the weight of the existing system by double-integrating the volume. The new system will be ready for a future full unmanned system with integrated pores for remote control, state-of-the-art digital features, and more than 90% efficiency/power factor against 80% efficiency/power factor of the existing system.

• 한국정밀공학회지
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• 제28권7호
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• pp.761-768
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• 2011

The large surface micro machining system includes the equipments and processes for manufacturing the ultra precision micro patterned products with large surface through the mechanical machining. Recent major issue on the micro machining technology may be the development of optical parts for the back light unit of display which has the largest market. This special issue makes up with three parts; the large surface micro machining system and machine, machining process and forming process. In this paper, the state-of-the-art and core technology of large surface micro machining system is introduced with focus on the manufacturing technology for the back light unit of LCD TV. Then, some research results on the development of a roll die lathe is introduced which involves the concept of machine design, improvement of thermal characteristics in the spindle system, improvement of relative parallelism and straightness between spindle system and long stroke feed table, machining of micro pitch patterns. Finally, the direct forming process is introduced as the future work in the large surface micro machining field.

• Corrosion Science and Technology
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• 제21권5호
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• pp.390-411
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• 2022

Any design engineer or coating formulator's primary objective is to protect metals. Large investments in terms of money, time, labour, and other resources are necessary for constructing large-scale machinery and structures. In terms of economy, the structure's lifespan should be as long as feasible to create revenue. It is becoming essential to protect metal substrates from corrosion to prolong the lifespan of such huge structures. One of the most exciting, durable, useful, and effective methods to protect metals from corrosion is the application of corrosion-resistant coating. Graphene is a novel material with a wide range of applications because of its extraordinary features. The use of graphene in coating creates an obstacle and complicates the path for corrosive medium to reach the metal. As the path to the metal elongates, the corrosion medium takes longer to reach the metal. Thus, metal corrosion can be avoided. In this paper, the importance of graphene in coating formulation is discussed, including chemical modifications of graphene, the effect of graphene concentration on corrosion inhibition, and the contact angle of coating. This review also highlights the significance of water-based corrosion-resistant coating for preventing environmental damage.