• The Transactions of the Korea Information Processing Society
• /
• v.4 no.7
• /
• pp.1900-1906
• /
• 1997

In this paper, the efficient BILBO(named EBILBO) is designed for BIST that is able to batch the testing when circuit is designed on FPGA. The proposed algorithm of batch testing is able to test the normal operation speed with one-pin-count that can control all part of large and complex circuit. PRTPG is used for the test pattern and MISR is used for PSA. The proposed algorithm of batch testing is VHDL coding on behavioral description, so it is easily modified the model of test pattern generation, signature analysis and compression. The EBILBO's area and the performance of designed BIST are evaluated with ISCAS89 benchmark circuit on FPGA. In circuit with above 600 cells, it is shown that area is reduced below 30%, test pattern is flexibly generated about 500K and the fault coverage is from 88.3% to 100%. EBILBO for the proposed batch testing BIST is able to execute concurrently normal and test mode operation in real time to the number of $s+n+(2^s/2^p-1)$ clock(where, in CUT, # of PI;n, # of register, p is order # of polynomial). The proposed algorithm coded with VHDL is made of library, then it well be widely applied to DFT that satisfy the design and test field on sme time.

• Journal of Korean Society of Steel Construction
• /
• v.18 no.2
• /
• pp.251-259
• /
• 2006

In some cases, wooden structures are used for medium-rise buildings. It is therefore necessary to develop and test a new structural system for medium-rise buildings using wooden structures. This study deals with high-performance, laminated, timber-based composite members, which consist of structural laminated timber and H-beam. Simple beam tests were performed to determine the strength, stress distributions, and failure patterns of laminated timber. The main parameters are the insertinglength (1, 1.5, and 2 times the H-beam height) and the epoxy between the top/bottom flange of the H-beam and the top/bottom flange of the laminated timber. The results of the test show that the specimen with an inserting length that is 2 times the H-beam height was characterized by fairly god strength and stiffness.

• Journal of Korean Society of Steel Construction
• /
• v.17 no.4 s.77
• /
• pp.459-467
• /
• 2005

This study focuses on the development of a new method of H-shaped beam-to-square column connection with an outer diaphragm and a field welding. The specific type of beam-to-column connection with an external stiffener, using field welding, is proposed. The structural behavior of this connection was examined experimentally. Two loading type tests were conducted under the experimental parameters given as details. First described was the symmetrical loading test, which supported both ends or a beam simply and applied a load from the column to the pend (What does this mean?) to investigate a fundamental characteristic of this connection. Further described was the anti-symmetrical loading test, which carried out simple support of the column'stop end and the column base, and applied a load from both ends of a beam to investigate the structural performance of this connection. From the results, it is clear that the external- stiffener-type connection proposed in this paper is the reliable connection method.

• Journal of Korea Society of Industrial Information Systems
• /
• v.5 no.3
• /
• pp.111-116
• /
• 2000

There are many recent monitor manufacturing firms not equipped with automatic checking system in their final process. And the check is based on the human perception, so the automatic checking system is needed for the consistency and the accuracy of the checking process to elevate the productivity and the quality. As the performance of computer systems and the vision systems has been increased, the cost for the system is reduced and their applicable algorithms have been developed. In this study we develop monitor checking system which is low-cost, fast, and easy to adopt by the small-scaled manufacturing films. The system is based on the computer vision techniques, and is equipped with the GUI interface and checking functions such as centering, yoke rotation, pincushion, sizing, brightness, and grayscale tracking. Monitor checking system developed in this study can be used in the final checking process thereby we expect the synergy effects both on the efficiency of production and on the reduction of the cost for the facility investments.

• Journal of Advanced Navigation Technology
• /
• v.24 no.4
• /
• pp.314-321
• /
• 2020

Logic automated stimulus and response (LASAR) software is an automatic test program development tool for logic function test and fault detection of avionics components digital circuit cards. LASAR software needs to the information for the logic circuit function and input and output of the device. If there is no component information, normal component modeling is impossible. In this paper, component modeling is carried out through reverse design of programmable logic device (PLD) device without element information. The developed LASAR program identified failure detection rates through fault simulation results and single-seated fault insertion methods. Fault detection rates have risen by 3% to 91% for existing limited modeling and 94% for modeling through the reverse design. Also, the 22 case of stuck fault with the I/O pin of EP310 PLD were detected 100% to confirm the good performance.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.20 no.10
• /
• pp.679-688
• /
• 2008

Air-heating vaporizer usually is used to regasify LNG at satellite areas because of the small demand of natural gas there. The common type of air heating vaporizer which exists in the market is the longitudinally finned type with 8 fins, 55 mm fin length and 2mm fin thickness. To contribute in developing an efficient air-heating vaporizer, experiment on finned type air-heating vaporizer using 8 fins, 50mm(fin length) with 2 mm(fin thickness) which exist in the market and 4 fins, 75 mm(fin length) with 2 mm(fin thickness), which is proposed, were conducted. Then, both types of vaporizers are compared. The experiments were conducted in one hour by varying the ambient condition and the length of the vaporizer. The ambient air was controlled so that it has the same temperature, humidity and air velocity with air condition in every season available and the length was varied 4000 mm, 6000 mm and 8000 mm for each type of vaporizer. Additional experiment with longer duration, i.e. In this experiment, the main aspects in analyzing the characteristics of the air heating vaporizer the inlet-outlet enthalpy difference and the outlet temperature of the working fluid. $LN_2$ is used to substitute LNG because of safety reason. The results show that the characteristics of the finned type 4fin75le vaporizer are comparable to finned type 8fin50le vaporizer.

• Membrane Journal
• /
• v.29 no.3
• /
• pp.130-139
• /
• 2019

Various two-dimensional nano materials such as graphene, zeolite, and metal-organic framework have been utilized to develop an ultra-thin high-performance membrane for water purification, gas separation, and so on. Particularly, in the case of graphene oxide, synthesis methods and thin film coating techniques have been accumulated and established since early 2000s, therefore graphene oxide has been rapidly applied to membrane field. The multi-layered graphene oxide thin film can filter molecules separately by the molecular sieving of interlayer spacing between adjacent layers, and it is also possible to separate various materials depending on the surface functional groups or the degree of interaction to intercalated materials. This review mainly focuses on the nanofiltration application of graphene oxide. The major factors affecting the separation performance of graphene oxide membrane in solvent are summarized and other technical elements required for the commercialization of graphene oxide membranes will be discussed including stability issue and fabrication method.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.36 no.2
• /
• pp.131-136
• /
• 2023

Nanocomposites have been considered innovative composite materials that have multi-functionality and high performance. Because the incorporation of nanoscale fillers may significantly improve the electrical, mechanical, and thermal properties of composites, numerous extensive studies on the characterization of nanocomposites with nanoscale fillers have been performed. In particular, the development of nanocomposites using carbon-based nanoscale fillers (e.g., carbon nanotubes, carbon black, graphene nanoplates) have attracted much interest in the composite field. This paper provides a review of recent advances in the electrical/mechanical characteristics of nanocomposites, which are essential for their practical applications. Furthermore, this paper revisits the recent research on multi-scale modeling, which is a promising approach for predicting the characteristics of nanocomposites. The current challenges and future development potentials for multi-scale modeling are also discussed.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.697-698
• /
• 2013

최근에 유연한 성질을 갖는 전자기기들의 수요가 증가하면서, 그에 따라서 유연 전자기기를 뒷받침 해줄 수 있는 에너지 저장체의 유연한 성질도 중요성이 점점 부각되고 있으며 많은 연구가 진행되고 있다. 유연한 에너지 저장체의 많은 연구들이 유연한 금속 박막이나 특수 공정처리가 필요한 고분자를 이용하고 있으나, 대부분의 유연 에너지 소자들은 에너지 저장체의 성능에 비해 고온과 산 약품과 같은 환경이 필요하며, 비용과 시간이 많이 소모되고 있다. 그에 반해 섬유는 앞에서와 같이 특수 공정 처리가 따로 필요하지 않으며 상온에서도 손 쉽게 이용 가능하며, 신축성이 뛰어난 장점이 있기 때문에 효율적, 비용적으로 유연한 에너지 저장체에 유리한 소재이다. 몸에 해로운 산과 같은 약품처리의 필요도 없으며, 용매를 흡수하는 능력이 뛰어나기 때문에 용매를 이용한 도포 방법을 사용하면 다양한 물질을 폭넓게 적용 가능하다. 그리고 적용 분야에 맞춰서 섬유의 종류를 조절하면 다양한 성질을 갖는 천 기반의 에너지 저장체가 형성되며, 면 섬유가 수소 결합과 높은 반데르 발스 결합에 의해 탄소나노튜브와 결합하여 높은 에너지 밀도를 갖는 에너지 저장체를 형성하는 것을 분석한 논문들도 보고되고 있다. 면 섬유의 특수한 성질을 이용하여 에너지 저장체를 제작하고 이를 확인하기 위해서 일반 합성 섬유인 polyester와 면 섬유를 비교 제작하였으며, 용매의 형태로 손쉽게 도포 가능한 물질은 탄소 계열의 활물질들이며, 탄소 나노 튜브나 그래핀 등이 분산된 용액을 이용해 천에 도포 가능하다. 탄소 계열의 활물질들은 대표적인 슈퍼캐패시터 물질이며, 천에 도포를 함으로써 천 기반의 슈퍼캐패시터를 제작하였다. 일반 합성 섬유 polyester와 CNT를 결합한 형태의 전극은 최대 에너지 축전 용량(Maximum specific capacitance)이 53.6 F/g으로 나타났으며, 면 섬유와 CNT를 결합한 형태의 전극은 최대 에너지 축전 용량이 122.1 F/g으로 나타났다. 따라서 면 섬유에서 높은 에너지 저장 능력을 보이는 것을 실험적으로 확인하였으며, 에너지 저장 능력이 뛰어난 면 섬유를 다음 전극 디자인에서도 일률적으로 적용하였다. 슈도캐패시터의 대표적 물질인 금속 산화물인 망간 산화물(MnO2)을 3전극 도금 시스템을 이용하여 에너지 축전 용량과 에너지 밀도를 올리는 전극을 제작하였다. 특히 망간 산화물의 형태는 표면적을 극대화하기 위해서 평균 지름은 200~300 nm 정도 되는 나노 입자의 형태로 제작하였다. 그 결과, 확연하게 에너지 축전 용량이 향상되었으며, 최대 에너지 축전 용량은 282.0 F/g, 에너지전력 밀도는 14.2 Wh/kg으로 나타나서 금속 산화물의 형태가 주는 효과를 확인할 수 있었다. 하지만 나노 입자의 형태로 제작된 금속 산화물은 문제점이 발생하였다. 금속 산화물의 전기 전도성이 매우 낮기 때문에, 전기 전도성에 비례해서 전력 밀도의 값이 표현되는데, 전기 전도성이 급격히 감소하기 때문에 전력 밀도도 급격한 감소가 나타난다. 다음과 같이 전기 전도성 물질을 첨가하는 방법은 추가의 공정이 필요한 단점이 있지만 오직 기계적인 인장응력만을 가해서 에너지 밀도와 전력 밀도를 증가시키는 전극을 제작하였다. 인장응력을 섬유 기반의 전극에 가했을 시에 가닥들간의 접촉 증가와 CNT가 정렬되면서 특정 변형률(strain) 이전에서는 전기 전도성이 최대 50% 이상 증가하는 것을 확인할 수 있었으며, 선행 연구에서 보고되었다. 이를 이용해서 전기 전도성과 직결되는 전력 밀도의 양도 증가시키고 에너지 밀도의 증가 여부까지 확인한 결과 인장을 가하기 전 면 섬유의 전력 밀도와 에너지 밀도는 6.4 kW/kg and 6.1 Wh/kg으로 나타났으나 30% 변형 인장 후에는11.4 kW/kg과 7.1 Wh/kg으로 나타났다. 그리고 망간 산화물을 첨가한 전극 역시 4.9 kW/kg과 14.2 Wh/kg으로 나타났었으나 인장 이후 전력 밀도는 14.2 kW/kg, 에너지 밀도는 17.6 Wh/kg으로 확연하게 증가한 것을 확인하였다.

• Journal of Energy Engineering
• /
• v.25 no.4
• /
• pp.176-183
• /
• 2016

This study relates to a polymer electrolyte membrane for improved performance fuel cell, were researched with respect to properties required for driving a fuel cell. The bis(4-fluorophenyl)phenyl phosphine oxide was sulfonated using fuming sulfuric acid. Synthetic hydrophilic oligomer and the hydrophobic oligomer and the block copolymers were prepared via aromatic nucleophilic substitution polycondensation. A block copolymer structure and degree of sulfonation was analyzed by $^1H$-NMR and gel permeation chromatography(GPC) analysis. Thermal stability was confirmed by thermogravimetric analysis(TGA), block copolymer was stable at high temperature(>$200^{\circ}C$), The ion conductivity was measured in order to demonstrate the performance of fuel cell. Synthesis membrane was the increase of temperature was improved conductivity up to 58 mS/cm due to the influence of the developed ion clusters. The phase separation of the polymer was observed to make AFM analysis.