• 공업화학
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• 제5권3호
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• pp.501-508
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• 1994

방출조절성 약제를 개발하기 위한 방법으로 1-ethyl-6-fluoro-1, 4-dihydro-4-oxo-7-(1-piperazinyl)quitoline-3-carboxylic acid의 $C_3$ 위치를 Vilsmeier reagent로 chlorination하여 이를 dextran과 반응시켜 1-ethyl-6-fluoro-1, 4-dihydro-4-oxo-7-(1-piperazlnyl) quinoline-3-carboxylic acid-dextran 중합체약을 합성하였다. 중합체약에 대한 최소발육저지농도(MICs)로서 Gram 양성세균 Bacillus subtillis ATCC 6633, Staphyloccus aureus ATCC 25923, Mycrobacterium phlei IFO 3158 및 Salmonella typhimurium KCTC 1925에 대해서 각각 $5{\mu}g/ml$의 농도로 균의 발육을 억제하였다. Micrococcus luteus ATCC 9341에 대해서는 $80{\mu}g/ml$로 약한 활성을 보였을 뿐, Gram 양성세균들에 대하여 전반적으로 강한 저항성을 보여주었다. Gram 음성세균인 Escherichia coli KCTC 1039, Escherichia coli ESS, Klebsiella puenmouiae KCTC 1560 및 Psendomonas aeruginosa IFO 13130 균주들에 대해서도 각각 $5{\mu}g/ml$로 대조물질과 유사한 항균성을 보여주었다. 한편, quinolone계 항균제가 진균류에 대하여 감수성을 보이지 않는 것처럼 중합체약도 진균인 Candida albicans ATCC 10231에 대해서는 감수성을 보여주지 않았다.

• Journal of Welding and Joining
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• 제29권1호
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• pp.80-84
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• 2011

The weight reduction of the transportations has become an important technical subject Al and Al alloys, especially Al 5052 alloys have been being applied as door materials for automobile. One of the most widely known car weight-reduction methods is to use light and corrosion-resistant aluminum alloys. However, because of high electrical and thermal conductivity and a low melting point, it is difficult to obtain good weld quality when working with the aluminum alloys. Also, Pulse MIG welding is the typical aluminum welding process, but it is difficult to apply to the thin plate, because of melt-through and humping-bead. In order to enhance weld quality, welding parameters should be considered in optimizing the welding process. In this experiment, Al 5052 sheets were used as specimens, and these materials were welded by adopting new Cold Metal Transfer (CMT) pulse process. The proper welding conditions such as welding current, welding speed, torch angle $50^{\circ}$ and gap 0~1mm are determined by tensile test and bead shape. Through this study, range of welding current are confirmed from 100A to 120A. And, the range of welding speed is confirmed from 1.2m/min to 1.5m/min.

• 산업공학
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• 제21권3호
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• pp.322-332
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• 2008

Digital Virtual Manufacturing is a technology to facilitate effective product developments and agile productions by digital model representing the physical and logical schema and the behavior of real manufacturing system, and it includes product, resources, processes and plant. For successful applications of this technology, a digital virtual factory as a well-designed and integrated environment is essential. In this research, we constructed a sophisticated digital virtual factory of a Korean automotive company's press shop. For efficient constructions of a digital virtual factory useful to kinematic simulations and visualizations, we analyzed entire business process and detailed activities of press engineering. Also, we evaluated geometries, structures, characteristics and motions of a plant and machines in press shop. The geometric model and related data of a virtual press shop are built and managed by a modeling standard defined in this paper. The virtual manufacturing simulation of press machines is conducted to evaluate kinematic motions, cycle time and locations of components using geometric models and related data. It's for interference checks and productivity improvements. We expect that this virtual press shop helps us to achieve great savings in time and cost in many manufacturing preparation activities in the new car development process of automotive companies.

• 한국안전학회지
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• 제33권1호
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• pp.148-161
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• 2018

A traffic fatality by young people marked average annual decrease of 4.5% since 2011. Meanwhile, a traffic fatality by senior over 65 years old marked average annual increase of 7.9% for the last five years which means that the annual increase of traffic fatality by senior will be a serious problem. This study started questioning that senior drivers over 65 years old did not retain the same causal factor of fatal traffic accidents and thus extensively analyzed a risk of it by age group quantitatively, dividing the senior driver group into the early, middle and latter stages. Depending on the aging level, the risk of traffic fatality showed a wide difference in seven different types of traffic accidents generally, and happened to increase with latter and middle parts of the senior driver more than the early part. Therefore, this study proposes four policy suggestions: 1) The senior driver need to be offered customized driving educations and the improvement of road environment is also recommended. 2) Political assistance is needed to support and guide a safety related technology installation for the new or existing car. 3) Renewal of driving license and an aptitude test(physical examination, cognitive test) for drivers over 75 years old should take in a less than 3 years and an additional road test is needed as occasion demands. 4) Like the United States and Europe, development and extension of customized treatment guidebook for medical teams who examine senior drivers is needed and establishment of education and administration system that a supervisor of driving license renewal can impose safety restriction and American anonymity reporting system is considered to institutionalize in the medium to longer term.

• 한국자동차공학회논문집
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• 제22권2호
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• pp.175-181
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• 2014

A four-link mechanism consisting of torsion bars is used for opening the trunk lid in most midsize sedans. When the weight of the lid is in equilibrium with the spring force exerted by torsion bars, the lid stops opening at a pop-up height. However, the actual pop-up height has large deviations from the specified height even with the same parts in the same car model, which leads to quality issues. Automotive manufacturers have experienced this deviation problem despite much effort to resolve it. In this research, we developed a multi-body dynamics model for the analysis of pop-up deviation of a trunk lid with torsion bars, which can simulate the actual pop-up motion of the trunk lid by considering kinematic constraints of the motion and friction forces in joints. We could also determine the most important factor that governs the pop-up height by sensitivity analysis of all parts. The developed system can be used for the analysis of other trunk lid systems to control the tolerance of parts.

• 한국자동차공학회논문집
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• 제22권3호
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• pp.250-256
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• 2014

EV(Electric Vehicle) has many benefits such as prevention of global warming and so on. But due to driving source changing from combustion engine to battery and e-motor, new R&D difficulties have arisen which changing of desired vehicle performance and multidisciplinary design constraints by means of strong coupled multi-physics domain problems. Additionally, dynamics performances of EV becomes more important due to increasing customer's demands and expectations for EV in compare with internal combustion engine vehicle. In this paper suggests model based development platform of EV through integrated simulation environment for improving analyse & design accuracy in order to solve multi-physics problem. This simulation environment is integrated by three following specialized simulation tools IPG CarMaker, AVL Cruise, DYMOLA that adapted to each purpose. Furthermore, control algorithm of TV(Torque Vectoring) system is developed using independent driven e-motor at rear wheels for improving handling performance of EV. TV control algorithm and its improved vehicle performances are evaluated by numerical simulation from standard test methods.

• 소성∙가공
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• 제29권4호
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• pp.194-202
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• 2020

In this paper, experimental and numerical study on a combined sheet metal forming and plate forging of a seal part of a passenger car's hub bearing is conducted to develop the new process of which target is to remove machining process by plate forging and to achieve near-net shape manufacturing. The previous process of a sheet metal forming inevitably needed a machining process for making stepped sheet after conventional sheet metal forming in a progressive way. The stepped sheet is intended to be formed by plate forging in this study. Through the systematic way of developing the combined forming process using solid elements based-elastoplastic finite element method (FEM), several conceptual designs are made and an optimized process design in terms of geometric dimensioning and tolerance of straightness of the thin part is found, which is exposed to bending in metal forming of axisymmetric part. The predicted straightness measured by the slope angle of the tilted thin region is compared with the experimental straightness, showing that they are in a good agreement with each other. Through this study, a systematic approach to optimal process design, based on elastoplastic FEM with solid elements, is established, which will contribute to innovating the conventional small-scaled sheet metal forming processes which can be dealt with by solid elements.

• 융합신호처리학회논문지
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• 제15권4호
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• pp.148-154
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• 2014

본 논문에서는 교차로에 설치된 한 대의 카메라를 활용하여 각 도로로 유입, 유출 되는 교통량을 동시에 측정할 수 있도록 하였으며 그 데이터를 기반으로 영상처리를 통해 신호등을 자동으로 제어하는 새로운 시스템을 제안한다. 또한 왕복 8차선 교차로의 교통량을 한 대의 카메라로 모니터링 가능하게 하여 차선 1개당 1대의 카메라 또는 루프 코일을 사용하던 기존 방식보다 효율적으로 광범위한 교통량 흐름을 통계적으로 모니터링 할 수 있도록 고안하였다. 실시간으로 배경영상이 업데이트되므로 불규칙적인 조건을 갖는 실 상황에서도 자동차 객체가 효율적으로 검지되도록 하였으며 관심영역 설정으로 보다 정확도 높은 교통량 측정을 가능하게 하였다. 본 논문에서 제안한 신호등 자동제어 알고리즘을 이용하여 정체가 일어나기 전에 각 도로간 교통량을 조절함으로써 교통 정체로 발생하는 운전자의 시간 낭비 및 에너지 낭비를 예방할 수 있다.

• 지구물리
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• 제10권1호
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• pp.37-44
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• 2007

최근 인간의 지적 욕구 충족과 급속한 과학 기술의 발전으로 새로운 측위 시스템인 광역위성항법시스템이 개발되었다. 위치정보 산업은 과거 군사적인 목적뿐만 아니라 민간 목적으로 폭넓게 사용되고 있다. 이는 차량 및 항공 항법, 토목공사, GIS의 자료원, 텔레메틱스, 위치기반서비스 등에서 단순한 측위 시스템의 기능이 아닌 사회 기반 시설의 역할을 담당하고 있다. 미국에 의한 고의적 잡음은 해제되었지만, GPS의 독점과 의존은 절대적이다. 이에 본 연구에서는 순수민간 목적으로 제작되고 서비스 할 예정인 차세대 NSS인 유럽의 Galileo의 영향을 연구하기 위해 소프트웨어를 개발하였으며 이를 바탕으로 측위 기법별 분석을 통해 우리나라에 미치는 실질적인 영향을 분석하였다. 또한 위성수신고 도각을 높게 설정하여 도심지와 같은 차폐환경에서 GPS 단독처리에 의한 방법보다 GPS/Galileo 조합 형태의 우수성을 입증하였다.

• 전기전자학회논문지
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• 제24권1호
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• pp.97-105
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• 2020

열 영상은 온도에 따라 방출하는 에너지의 차이를 나타낸 영상이다. 주야간 사용이 가능하기 때문에 군사적인 용도로 많이 활용되고 있으나, 열 영상은 물체의 경계가 불명확하고 흐릿하게 표현되는 경우가 많으며 화염 등의 열기로 인해 경계부분이 변질되는 단점이 있다. 따라서, 열 영상을 이용하여 표적의 종류를 분류할 때 정확하게 분할된 경계선을 이용할 경우 효과적으로 분류 할 수 있지만, 물체의 경계가 잘못 추출되는 경우 분류의 정확도가 크게 감소한다. 본 논문에서는 이러한 단점을 극복하기 위해서 표적 영상의 분할 신뢰도에 따라 형태특징과 지역특징의 분류결과를 융합하는 계층적 분류기법을 제안하였으며, 연속 영상 기반으로 분류 결과를 갱신하는 기법을 새롭게 제안하여 차량 표적 분류 정확도를 개선하였다. 제안하는 방법은 실제 군용 표적 4종(전차, 장갑차, 상용차, 군용트럭)이 있는 다양한 자세의 열 영상 20,000장 이상을 이용하여 성능을 검증하였으며, 우수한 성능의 기존 방법 대비 정확도 개선에 효과가 있음을 확인하였다.