• Journal of Ocean Engineering and Technology
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• v.13 no.3 s.33
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• pp.29-35
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• 1999

At the design of Mark III membrane type LNG tank, an analytical and experimental approach on the fatigue strengths of membrane and its welds are very important in order to assist designers and surveyors. In this study, fatigue tests of lap weld of Mark III membrane type LNG tank were carried out and cumulative damage factor was calculated in order to estimate the fatigue life by probability density function and rule methods. It contained the following tests and reviews : 1) The fatigue tests of lap weld of stainless steel according to statistical testing method recommended by JSME, 2)Preparation of S-N curve for lap welds considering the statistical properties of the results of fatigue tests. 3) Procedure for estimating the initiation life of fatigue crack of lap welds under variable loads by the rule lf classification society and probability density function, 4) Guideline for inspection of lap welds fo membrane type LNG tank.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.1
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• pp.113-120
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• 2010

In case the traffic accident occurs, skid mark is very important factor to calculate the car speed. Especially, for the purpose of objective and scientific inspection, traffic accidents should be appraised and inspected by righteous material evidences, computer simulation, and studies such as automobile engineering, traveling and collision accident dynamics, road and traffic engineering. In this paper, it displays the results of studying cases with the reasons of traffic accidents by analyzing and studying automobile kinetics, real traffic accidents and the results of in scientific and objective ways. After computer simulation result that it is proved that compared with unpacked road condition and packed road condition. unpacked road condition is shorter than packed road condition.

• Transactions of Materials Processing
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• v.18 no.2
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• pp.172-176
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• 2009

In this paper, new aspherical surface polishing mechanism is suggested to polish aspherical glass lens mold by both airbag polishing tool and reverse-rotational eccentric motion. Up to now, conventional aspherical lens polishing method by the small tool polishing uses the aspherical surface profile and the trajectory of the polishing tool is also controlled. However, full contact concept by airbag polishing tool and no position control make the easy polishing setup and does not need aspherical design profile. An aspherical lens polishing machine was made for this study and a tool mark removal experiment fur the fine-grounded lens mold was successfully performed.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1737-1741
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• 1991

The authors proposed a new two-dimensional(2D) positioning system by use of M-array and correlation technique which is suitable for noisy environment in '88KACC and its revised versions in '89KACC and '90KACC. This system uses the property of M-array that the autocorrelation function of the M-array has a sharp peak at its origin. In this paper, a new mark pattern is developed, instead of M-array, with which the two-dimensional positioning system becomes robust to rotation error of TV camera. The property of the rotation-free pattern is checked under various conditions, and it is shown that, by use of this rotation-free pattern, the positioning system can be used not only in a noisy environment but also in a roughly aligned set up of the TV camera.

• Journal of the Korean institute of surface engineering
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• v.35 no.3
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• pp.113-120
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• 2002

Injection molded plastic parts have many surface defects. These include a weld line, sink mark, flow mark, gloss, shading, scratching etc. Because these surface faults are not aesthetically acceptable, plastic parts are produced through painting or texturing. The purpose of this paper is to develop paintless molded parts using a flow control method. Computer aided injection mold filling simulations were used in order to minimize the number of defects from injection molding. Based on the numerical results, FR(Flame Retardant) HIPS was developed and the guidelines for part design, mold design, and the processing conditions were established. The effects of cost savings, improvements in productivity, and recycling were considered by reducing the number of surface faults and eliminating the painting process.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.57.1-57.1
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• 2015

VLBI에서 관측 대역폭이 n배 증가될 경우 관측감도는 sqrt(n)만큼 향상되고, 이는 관측 연구 측면에서 기존에는 불가능하던 천체에 대한 연구 수행이 가능함을 의미한다. 관측 대역폭의 확대는 관측 데이터의 용량 증가를 의미하며 여기서 해당 데이터의 처리를 위한 초고속 데이터 기록시스템은 핵심적 역할을 한다. 이에 따라 현재 KVN에서는 미국 MIT Haystack 천문대에서 개발된 초고속 기록시스템인 Mark5B/B+와 Mark6를 운용 중에 있다. 하지만 이들 시스템의 경우 사실상 VLBI연구를 위한 목표로 특수 개발되었기에 유지 및 운영 측면에서 여러 불편이 있고, 성능에 있어서도 단일 스트림 기준으로 8Gbps를 넘지 못하는 한계를 안고 있다. 본 발표에서는 기존 시스템을 대체할 수 있는 기술로서 PCI 익스프레스 기반의 데이터 처리를 소개하고자 한다. 나아가 실제 관측 데이터에 대한 입출력 및 기존 시스템과의 성능 비교를 통해 광대역 관측 연구에 최적화된 기록 시스템을 제안하고자 한다.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.7 no.1
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• pp.22-31
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• 1996

1989년 5월 3일 발표된 EC(현 EU) Directive 89 / 336 / EEC(전자파 양립성 지령)에 의해, 1996년 1월 1일부터 EU 지역에서 생산 또는 EU 역내에 수입되는 모든 전기전자제품에 대해 CE Mark 가없이는 유통, 판매, 사용이 금지되기 시작했다. 이 지령은 EMC에 관한 각종 제품의 보호요건을 정의하고 있으며, 타제품 및 부문에 대해서도 EU 위 원회에서 제정한 각종 안전규정(Directives; 지령)에 적합할 경우, CE Mark를 부착하고, 이는 구주 역 내 국가간에 규제를 통일하고 안전성이 확보된 제품의 자유로운 유통(Free Movement of Goods)과 판매를 목적으로 한다. 이에 따라, EU위원회에서는 EMC를 비롯한 안전, 기계, 완구 등 여러 분야에 대해 각국의 규제를 조 정하고 일체화하여 현재까지 약 20종류의 EC지령을 발표하였다.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.112-118
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• 2002

Injection molding process factors such as molding temperature, injection pressure, flow rate and flow velocity, must be controlled properly in filling and packing phases in the injection molding process. In this study, effects of these factors on the injection molding were investigated through the flow analysis fur the filling and packing phases. Molding troubles like flow mark, weld line, sink mark, short shot and warpage can be caused by these injection molding process factors. Among them, the short shot was caused by that the packing pressure could not reach properly to the filling end part in the packing phase and hence the flow rate could not be supplied to the full. In addition, as the flow rate for the volumetric shrinkage during the frozen phase could not be supplied properly by the packing pressure, the short shot appeared. Here, the volumetric shrinkage reduced with increasing the packing pressure and also the warpage of molded part increased with increasing the packing pressure.

• Archives of design research
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• v.16 no.3
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• pp.143-150
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• 2003

An icon which is used in website as a role of a mark is an important device, what is called, to find the contents The users get satisfied with their internet surfing when visualization of icon has exactly the right content. Therefore, visualization of contents - performing more fast and more convenient functions in searching a right content which a user want - becomes much more important. In this study, we researched the expressive ways of con indicating the common contents in the website, we divided into a visible and an invisible content, analysed the cases in symbolic situation and finally suggested the most appropriate method of visualization in each type.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2001.05a
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• pp.20-25
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• 2001

In recent years, the concern about a user center design in increasing, and it's needed to task a user's visual cognitive characteristics for information presentation. Then this study aims to grasp user's cognitive characteristics about the information presentation by analyzing the fixation points. In the experiment, actually subject operated a copy machine. Recorded the fixation point movement of the operation panel by the eye mark recorder. Analysis examined the screen interface of the operation panel from the field of a fixation point trace. The top down type fixation oder by experience or the context became clear as a result. Furthermore, the difference of the fixation order by skill level was also examined. In this study, it was assumed that to grasp the visual cognitive characteristics becomes the key of efficient information.