• Journal of Energy Engineering
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• v.18 no.3
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• pp.147-155
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• 2009

Demand for distributed source by new and renewable energy has been gradually increasing recently. For the characteristics of distributed generation, distributed source is located near the distribution system and customers' buildings and can be operated in standalone mode or in interface mode with distribution system. When the distributed sources are interfaced with distribution system, the standard for interfacing distributed source with existing distribution system and operation manual should be updated with revisions in order to manage the distributed source effectively and operate the distribution system stably because how to operate the interfaced system is different from that of existing distribution system. In this paper, the FEP(Front End Processor) using the international standard protocol IEC-60870 for interfacing with distributed resources was designed. The designed system was verified via the test result using main control system for distributed generation and RTU(Remote Terminal Unit) for interface with distributed power generating.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.3 s.106
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• pp.239-248
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• 2006

In this paper, the cryogenically cooled low noise amplifier module for radio telescope receiver front-end using pHE-MT MMIC is designed and fabricated. In the selection of MMIC, the MMIC fabricated with the pHEMTS providing successful cryogenic operation are chosen. They are mounted in the housing using the thin film substrate. In the design of the housing, the absorber and the elimination of the gap between the carrier and the housing as well removed the unnecessary oscillations by its structure. The mismatch is improved by ribbon-tuning to provide the best performance at room temperature. The fabricated module shows the gain of $35dB{\pm}1dB$ and the noise figure of $2.37{\sim}2.57dB$ at room temperature over $21.5{\sim}23.5GHz$. In the cryogenic temperature of $15^{\circ}K$ cooled by He gas, the measured gain was above 35 dB and flatness ${\pm}2dB$ and the noise temperatures of $28{\sim}37^{\circ}K$.

• Journal of the Korean Society of Systems Engineering
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• v.9 no.2
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• pp.37-53
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• 2013

With rapid growth of the world plant market, an increasing attention is paid on the plant engineering. Up to present time, Korean plant engineering technology has been concerned with the down stream part of the plant engineering, so called EPC, considered as a lower value chain compared with the up stream, composed of FEED(Front End Engineering Design) and PMC(Project Management Consultancy). In other words, a key issue for Korean plant industry is how to catch up the FEED technology, currently occupied by the advanced countries. In this paper, we propose an SE(Systems Engineering) approach, conventionally applied for aerospace and defense industry, to the FEED for plant engineering. Specifically, we proposed a new SE process composed of: 1) SPA matrix for reverse systems engineering, and 2) PPA matrix for forward systems engineering. To illustrate the proposed method, a case study for an environmental plant is performed.

• Journal of Korean Society of Transportation
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• v.30 no.2
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• pp.127-136
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• 2012

Multi-car rear-end collision accidents have three categories: sequential collision from the rear which is commonly referred to as chain reaction collision, sequential collision from the front, and mixed-order collision. This paper suggests several effective methods of reconstruction analysis for multi-car rear-end collision accidents. First, by incorporating the traditional empirical method which uses vehicle damage caused by brake dive and passenger injuries, with results of theoretical analysis made within mechanics of rigid body, it is made possible for the method to be put to immediate practical use. A methodology to precisely analyze multi-car rear-end collision accidents was suggested using a simulation program simultaneously with a video event data recorder which is starting to be widely used in domestic vehicles. To go beyond the simple intuitive analysis of the video event data recorder, the simulation analysis based on the results of video analysis was executed to acquire various information, so that the causes and responsibility could be clearly stated.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.815-817
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• 2012

본 논문에서는 차량 충돌 예방 레이더 시스템-온-칩용 77GHz 고주파 전단부(RF front-end)를 제안한다. 이러한 고주파 전단부는 77GHz의 동작주파수를 가진 저 잡음 증폭기와 고주파 전력 증폭기로 구성된다. 이러한 회로는 TSMC $0.13{\mu}m$ 혼성신호/고주파 CMOS 공정 ($f_T/f_{MAX}=120/140GHz$)으로 설계되어 있다. 저잡음 증폭기의 경우 전압이득이 36dB로 최근 발표된 연구결과 중 가장 우수한 수치를 보였다. 전력 증폭기는 포화전력과 출력 $P_{1dB}$이 18dBm과 15dBm으로 기존 연구결과 중 가장 우수한 결과를 각각 보였다.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.1
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• pp.88-99
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• 1998

In assembly, misalignment must be detected and compensated for during the mating period, regardless of the complexity of the cross-sectional shape. To this end, we propose a novel omnidirectional image sensing system for assembling parts with complicated shapes(OISSA) and its feasibility for detecting the misalignment between mating parts is shown by a series of simulations. This system encompasses a camera with an optical unit attached to the front of the camera. The optical unit consists of a pair of plane mirrors and a pair of conic mirrors. Utilizing the proposed sensing system, a 2$\pi$ coaxial image of the misalignment along the mating boundary interface between mating parts can be immediately obtained without experiencing self-occlusion.

• 월간 기계설비
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• s.223
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• pp.75-78
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• 2009

전통적으로 주요 EPC(설계, 구매, 시공) 공사는 최초의 엔지니어링 작업(FEED : Front End Engineering Design)을 한 후, 경쟁입찰을 하여 총액계약(Lamp Sum)으로 공사를 수행했다. 최근에 EPC시공자의 위험부담을 줄이는 한편, 발주자는 경쟁적인 시공자를 확보할 수 있는 기회를 확대하면서 협상기간을 단축하교 조기착공을 위해, Lump Sum 가격을 늦게 결정하는 방법을 고려한다. CLST(Converted Lump Sum Turnkey)계약방식은 최초의 엔지니어링 작업을 한 후 경쟁입찰을 통해 1차 계약을 맺고(설계 및 특별 자재 공급에 대한) 공사를 수행하다 설계가 충분히 진행되고 핵심자재에 대한 견적이 입수되어 발주 가능한 시점 및 하도급사를 선정할 준비가 된 시점에서 1차 계약을 변경해 2차 계약을 맺는다. 2차 계약 시 1차 시 맺은 계약조건(직접공사비, 일반관리비 및 이윤, 최대한도 금액이 포함됨)을 기준으로 하되, 발주자가 Open Book 형식으로 공사비를 평가하고 재협상하여 Lump Sum 금액으로 전환해 합의한다. 이후 Lump Sum Tumkey 계약과 동일한 형식으로 공사를 수행한다.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.6
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• pp.785-795
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• 2019

This paper is a study on the modeling of the quantity estimation model for offshore plant Material handling equipment in FEED(Front End Engineering Design) verification stage using system engineering approach which is an engineering design methods. The relevant engineering execution procedure is not systemized although the operation method and Material handling equipment selection with weight and space constraints is a key part of the FEED. Using the system engineering process, the stakeholder requirements analysis process, the system requirements analysis, and the final system architecture design were sequentially performed, and the process developed through the functional development diagram and Requirement traceability matrix (RTM) was verified. In addition, based on the established process, we propose a Material handling quantity estimation model and Quantity calculation verification Table that can be applied at the FEED verification stage and we verify the applicability through case studies.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.1
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• pp.151-159
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• 2003

The front 2 pieces of the 3-piece steel propeller shaft installed on a 8.5-ton truck were redesigned with a 1 -piece composite propeller shaft with steel yokes and spline parts to get the reduction of weight and the improvement of NVH characteristics. Based on the analysis of bending vibration, strength and cure-induced residual stresses of the composite propeller shaft, proper composite materials and stacking sequences were selected. The composite propeller shaft requires a reliable joining method between the shaft and steel end parts through a steel connector. From 3-D contact stress analyses of the laminated composite shaft with bolted Joints, the 3-row mechanical joint which satisfies the torque transmission capability has been designed. Several full-scale composite shafts were fabricated and tested to verify the design analyses. The design requirements are shown to be satisfied. With the newly designed composite shaft, the weight reduction more than 50% and improvements in NVH characteristics have been achieved.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.1
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• pp.347-354
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• 2013

In the recent global construction environment, EPC contracts that integrate planning, design, procurement, and construction have been widely used for industrial facilities. Similarly, as the importance of the engineering capability such as project management consulting(PMC) and front end engineering design(FEED) has been increased, design-build contracts also have been gradually adopted for infrastructure projects. Whereas, the Korean infrastructure industry has fragmentary features which mainly emphasize on the construction sector. Therefore, this study aims at developing strategies for enhancing the engineering capability and for balancing the competitiveness between engineering and construction sectors in the Korean infrastructure industry. To this end, the authors first carried out market analysis for both global and domestic market. Then, a structured survey and expert in-depth interviews were sequentially performed in order to reflect practitioners' perspectives and needs for institutional strategies. As a result, five strategies drawn from this study are as follows: 1) rearranging the government's roles for supporting the engineering sector; 2) establishing institutional bases being compatible with global standards; 3) fostering value-added workforce for undertaking complex tasks; 4) constructing an consortium between an engineering association and general contractors; and 5) building a nationwide collaborative networks for overseas market expansion.