• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2008년도 추계학술대회 논문집
• /
• pp.422-429
• /
• 2008

The objective of the present study is to develope a propultion unit cooling system for the next-generation High-speed EMU. The propulsion power control unit consists of some IGBT semiconductors. In general, those power semiconductors are very sensitive to temperatures and need a cooling system to keep them at a proper operational conditions in the range of $50{\sim}100^{\circ}C$. In this first year of study, we tried to focuss on the understanding of fundamental technologies for each of the two different cooling systems and collecting basic data for design and manufacturing for both cases. For the water cooling system, a heat sink with multi channels of liquid flow was considered and a model unit was designed and performance test was conducted. For the heat pipe cooling system, a Loop Heat Pipe(LHP) was considered as an element to transport heat from IGBT to environment air flow and a model unit was designed and performance test was conducted. The analysis using SINDA/FLUINT showed that those design parameters are good enough for the LHP to properly operate under a heat load up to around 360W.

• 한국전기전자재료학회논문지
• /
• 제34권6호
• /
• pp.401-415
• /
• 2021

Soft robots are promising devices for applications in drug delivery, sensing, and manufacturing. Traditional hard robotics are manufactured with rigid materials and their degrees of motion are constrained by the orientation of the joints. In contrast to rigid counterpart, soft robotics, employing soft and stretchable materials that easily deforms in shape, can realize complex motions (i.e., locomotion, swimming, and grappling) with a simple structure, and easily adapt to dynamic environment. Among them, the magnetic actuators exhibit unique characteristics such as rapid and accurate motion control, biocompatibility, and facile remote controllability, which make them promising candidates for the next-generation soft robots. Especially, the magnetic actuators instantly response to the stimuli, and show no-hysteresis during the recovery process, essential for continuous motion control. Here, we present the state-of-the-art fabrication process of magnetically controllable nano-/micro-composites, magnetically aligning process of the composites, and 1-dimensional/multi-dimensional multimodal motion control for the nextgeneration soft actuators.

• 전자통신동향분석
• /
• 제36권3호
• /
• pp.12-22
• /
• 2021

Since the technical realization of self-aligned planar complementary metal-oxide-semiconductor field-effect transistors in 1960s, semiconductor manufacturing has aggressively pursued scaling that fruitfully resulted in tremendous advancement in device performances and realization of features sizes smaller than 10 nm. Due to many intrinsic material and technical obstacles, continuing the scaling progress of semiconductor devices has become increasingly arduous. As an effort to circumvent the areal limit, stacking devices in a three-dimensional fashion has been suggested. This approach is commonly called monolithic three-dimensional (M3D) integration. In this work, we examined technical issues that need to be addressed and overcome to fully realize energy efficiency, short latency and cost competency. Full-fledged M3D technologies are expected to contribute to various new fields of artificial intelligence, autonomous gadgets and unknowns, which are to be discovered.

• 한국염색가공학회지
• /
• 제35권2호
• /
• pp.121-127
• /
• 2023

In this study, a comprehensive investigation was conducted on the morphological and property changes of laser-induced nanocarbon (LINC) as a function of laser process parameters. LINC was formed on the surfaces of polyimide films with different backbone structures under various process conditions, including laser power, scan speed, and resolution. Three different forms of LINC electrodes (i.e., continuous 3D porous graphene, wooly nanocarbon fibers, line cut) were formed depending on the laser power and scan speed. Furthermore, heteroatom doping induced from the chemical structure of the polyimide during laser patterning was found to be effective in modifying the electrical properties of LINC electrodes. The LINC surfaces exhibited different microstructures depending on the laser beam resolution under constant laser power and scan speed, allowing for controllable surface wettability. The correlation between the chemical structure of the polymer substrate, laser process parameters, and carbonized surface properties in this study is expected to be utilized as fundamental understanding for the manufacturing of next-generation carbon-based electronic devices.

• 융합보안논문지
• /
• 제22권3호
• /
• pp.13-18
• /
• 2022

IT 기술의 급속한 발전과 함께 기존 산업과의 융합을 통해 4차 산업혁명 기술을 기반으로 프로세스의 간소화 및 생산성을 높일 수 있는 스마트 제조가 증가하고 있으며, 이와 비례하여 공급망 공격에 대한 보안위협도 증가하고 있다. 공급망 공격의 경우 사전 탐지가 힘들고 피해 규모가 매우 크다는 점 때문에 차세대 보안 위협으로 부상하고 있으며 이에 따른 탐지 기법에 대한 연구가 필요하다. 따라서 본 논문에서는 오픈소스 기반 분석 솔루션인 ELK Stack과 Sysmon을 통해 다중 환경에서 실시간으로 로그를 수집, 저장, 분석 및 시각화하여 공급망 공격에 대한 이상 행위 등의 정보를 도출하여 효율적인 탐지 기법을 제공하고자 한다.

• 한국산학경영학회:학술대회논문집
• /
• 한국산학경영학회 2005년도 추계학술발표대회 발표논문집
• /
• pp.29-46
• /
• 2005

최근에 국내에서 TPS(Toyota Production System)에 대해 기업이나 제조업 관련 사람들에게 많은 관심을 불러일으키고 있다. TPS는 일본형 생산시스템의 대표적 모델이며, 21세기 후반 생산기술 분야에 많은 기여를 하고 있으며 그 성과 역시 높은 평가를 세계 여러 기업으로부터 받고 있다. 본 연구에서는 TPS의 기본 개념과 특성 그리고 적용 절차 등 TPS의 현재 모습을 통해 기존의 TPS가 안고 있는 문제점과 한계를 조명하고자한다. 이를 통해 현재의 TPS를 앞으로도 지속적으로 적용하고 경쟁력 있는 시스템으로 발전시키기 위한 방안으로 NEW JIT 기법을 활용하고자한다. NEW JIT는 고객제일의 품질관리를 목표로 판매, 개발 그리고 생산의 각 부분의 업무프로세스를 혁신하는 것이다. 하드웨어 시스템으로는 TMS, TDS, TPS로 구성되며, 소프트웨어 시스템은 과학적 SQC(TQM-S)를 이용한 TQM의 전개로 이루어진다. 따라서 앞으로 차세대 제조관리기술을 위해 NEW JIT 기법을 보다 더 우리의 기업환경에 적합하도록 활용할 수 있는지를 검토하고 연구 발전시켜야 한다.

• 한국생산제조학회지
• /
• 제23권3호
• /
• pp.310-317
• /
• 2014

The Next-generation High-speed Rail Technology Development Project was started in 2007 by the Korean Government with the aim of developing the core technologies for a high-speed electric multiple unit (EMU) railway system. This is the first attempt to develop a high-speed EMU railway. High-speed EMU trains have superior acceleration and deceleration compared to push-pull high-speed railways such as KTX(Korean Train eXpress). A prototype train was developed and tested on a high-speed line starting in 2012. The new train must maintain running safety during the test. Generally, the international standard (UIC518) is adopted to evaluate the running safety of trains. This method suggests that the test zone must have over 25 sections, and the length of each section must be 500 m. However, it is difficult to implement these test conditions for a real high-speed line. In this study, we analyzed the running safety using several test section lengths (100 m to 500 m) and compared the results. The results of this study will be used to establish a running safety evaluation method for high-speed EMU railways.

• 한국안전학회지
• /
• 제28권5호
• /
• pp.5-9
• /
• 2013

Recently, eco-friendly sources of energy by fuel cells that use hydrogen as an energy source has emerged as the next generation of energy to solve the problem of environmental issues and exhaustion of energy. A solid oxide fuel cell(SOFC) classified based on the type of ion transfer mediator electrolyte has actively being researched. However, the reliability according to the thermal cycle is low during the operation of the fuel cell, and deformation problem comes from the difference in thermal expansion coefficient between the electrode material, the components made of ceramic material is also brittle, which means disadvantages in terms of the strength. Therefore, in this study, considering the states of the manufacturing and operating of SOFC single cells, the stress analyses in the each of the interfacial layer between the anode, electrolyte and the cathode were performed to get the basic data for reliability assessment of SOFC. The obtained results show that von Mises stress according to the thickness direction on operating state occurred maximum stress value in the electrolyte layer. And also the stresses inside the active area on a distance of 1 ${\mu}m$ from the electrode interface were estimated. Futhermore the evaluation was done for the variation of the stress according to the stage of the operation divided into three stages of manufacturing, stack, and operating.

• 한국기계가공학회지
• /
• 제16권2호
• /
• pp.69-80
• /
• 2017

In or To use, manage, and preserve sustainable water resources for the current and future generations amid the threat of abnormal climate, it is necessary to establish a smart water grid system, the next-generation intelligent water management system. In this study, sensors, which make use of the five senses to watch, listen, and detect machine vibration, bearing temperature, machine operation sounds, current, voltage, and other symptoms that cannot be verified when the irrigation facilities are running, are used to establish various decision-making criteria appropriate to on-site situations. Based on such criteria, the unmanned conditions in the facilities were verified and analyzed. Existing technologies require on-site workers to check any defects caused by overloading of machines, which is the biggest constraining factor in the application of an unmanned control system for irrigation facilities. The new technology proposed in this study, on the other hand, allows for the unmanned analysis of the existence of machine vibration. This controls the decision-making process of any defect based on the analysis results, and necessary measures are taken automatically, resulting in improved reliability of the unmanned automation.

• 산학경영연구
• /
• 제19권1호
• /
• pp.93-114
• /
• 2006

최근에 국내에서 TPS(Toyota Production System)에 대해 기업이나 제조업 관련 사람들에게 많은 관심을 불러 일으키고 있다. TPS는 일본형 생산시스템의 대표적 모델이며, 21세기 후반 생산기술 분야에 많은 기여를 하고 있으며 그 성과 역시 높은 평가를 세계 여러 기업으로부터 받고 있다. 본 연구에서는 TPS의 기본 개념과 특성 그리고 적용 절차 등 TPS의 현재 모습을 통해 기존의 TPS가 안고 있는 문제점과 한계를 조명하고자 한다. 이를 통해 현재의 TPS를 앞으로도 지속적으로 적용하고 경쟁력 있는 시스템으로 발전시키기 위한 방안으로 NEW JIT 기법을 활용하고자 한다. NEW JIT는 고객제일의 품질관리를 목표로 판매, 개발 그리고 생산의 각 부분의 업무프로세스를 혁신하는 것이다. 하드웨어 시스템으로는 TMS, TDS, TPS로 구성되며, 소프트웨어 시스템은 과학적 SQC(TQM-S)를 이용한 TQM의 전개로 이루어진다. 따라서 앞으로 차세대 제조관리기술을 위해 NEW JIT 기법을 보다 더 우리의 기업환경에 적합하도록 활용할 수 있는지를 검토하고 연구 발전시켜야 한다.