• 한국철도학회논문집
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• 제11권4호
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• pp.384-389
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• 2008

궤도구성품 중 도상은 레일과 침목으로 전달되는 열차하중을 노반으로 전달하는 중간매개체 역할을 하며, 도상자갈의 열화는 궤도틀림 진전에 직접적으로 영향을 미친다. 본 연구에서는 대형 보선장비(멀티플 타이 탬퍼; MTT; Multiple Tie Tamper)를 사용한 도상다짐작업과 누적통과톤수가 자갈 세립화 및 도상열화의 주요 원인이다. 도상자갈의 열화특성을 파악하기 위하여 시험용 궤도 부설을 통한 현장실험(2장. 실외 실측시험)과 실제의 운행 환경을 모사한 모형실험(3장. 실내 모형실험)을 실시하였고 실제 운용중인 고속선에서 채취한 시료의 파쇄입자 비율과 비교분석하였다.

• 한국컴퓨터그래픽스학회논문지
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• 제3권2호
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• pp.85-97
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• 1997

이 연구의 목적은 유한요소법에 의해 계산된 3차원 고체의 응력 분포를 등가면 (iso-surface)을 이용하여 이해하기 쉽게 가시화하는 방법을 제시하고, 이와 관련된 효율적인 알고리즘을 개발하며, 등가면 표시방법의 실용적 응용방법을 개척하는데 있다. 이 논문은 등가변을 생성하는 방법과, 생성된 등가연의 국부적인 불규칙성을 제거하고, 연속적이며 완만하게 굴곡된 곡면으로 평활화하는 방법을 제시하였다. 등가면을 이용한 여러가지 응력 표시방법을 고안하고, 이들의 실제적인 이행과 사례적인 실행을 통해서 그 실용성과 효용성을 검토하였다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2002년도 추계학술대회 논문집
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• pp.73-78
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• 2002

Ships and ocean structures are generally under random loading. Various type of variable-amplitude loading affects fatigue crack growth and fatigue life. However interaction effects due to irregularity of loading including random loading have not explained exactly and it is difficult to examined fatigue crack growth behaviour and fatigue life for this reason. Therefore in this paper crack growth tests with constant-amplitude loading including a single overload were conducted to measure plastic zone size near crack tip of DENT specimen. And the observed plastic zone sized were discussed in terms of crack growth rate. As a result of this the effect the plastic rue size due to the overload is examined on the effect on crack growth rate and, consequently, fatigue life.

• Earthquakes and Structures
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• 제5권3호
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• pp.297-319
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• 2013

Two destructive earthquakes occurred on October 23 and November 9, 2011 in Van province of Turkey. The damage in residential units shows significant deviation from the expectation of decreasing damage with increasing distance to epicenter. The most damaged settlement Ercis has the same distance to the epicenter with Muradiye, where no damage occurred while relatively less damage observed in Van having half distance. These three cities seem to have resembling soil conditions. If the damages are evaluated: joint failures and insufficient lap splice lengths are observed to be the main causes of the total collapses in RC buildings. Additionally, low concrete strength, reinforcement detailing mistakes, soft story, heavy overhang, pounding and short columns are among other damage reasons. Examples of damages due to non-structural elements are also given. Remarkable points about seismic damages are: collapsed buildings with shear-walls, heavily damaged buildings despite adequate concrete strength due to detailing mistakes, undamaged two-story adobe buildings close to totally collapsed RC ones and undamaged structural system in buildings with heavily damaged non-structural elements. On the contrary of the common belief that buildings with shear-walls are immune to total collapse among civil engineers, collapse of Gedikbulak primary school is a noteworthy example.

• 한국전기전자재료학회논문지
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• 제31권4호
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• pp.255-260
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• 2018

In recent years, increasing electricity use has led to considerable interest in green energy. In order to effectively supply, cut off, and operate an electric power system, many electric power facilities such as gas insulation switch (GIS), cable, and large substation facilities with higher densities are being developed to meet demand. However, because of the increased use of aging electric power facilities, safety problems are emerging. Electromagnetic wave and leakage current detection are mainly used as sensing methods to detect live-line partial discharges. Although electromagnetic sensors are excellent at providing an initial diagnosis and very reliable, it is difficult to precisely determine the fault point, while leakage current sensors require a connection to the ground line and are very vulnerable to line noise. The partial discharge characteristic in particular is accompanied by statistical irregularity, and it has been reported that proper statistical processing of data is very important. Therefore, in this paper, we present the results of analyzing ${\Phi}-q-n$ cluster distributions of partial discharge characteristics by using K-means clustering to develop an expert partial discharge diagnosis system generated in a GIS facility.

• 한국전기전자재료학회논문지
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• 제13권3호
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• pp.241-246
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• 2000

We fabricated Bi-2223 multi-filaments superconductor tape and evaluated the effect of twisting on the microstructural evolution and critical current. Twist pitches of the tapes are in the range of 70- 8mm and uniformly deformed. It was observed that grain size and the degree of texture decreased as decreasing pitch probably due to the formation of the irregular interface between Ag and filaments. In addition critical current of the tapes decreased to 6.5 A with decreasing pitch to 8mm, showing 48% of degradation compared to the untwisted tapes decreased to 6.5 A with decreasing pitch to 8mm, showing 48% of degradation compared to the untwisted tape(12.5 A). These reduction of critical current may be related to the interface irregularity smaller grain size worse texture and the presence of cracks due to the induced strain during twisting processing.

• 한국의류학회지
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• 제29권11호
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• pp.1410-1420
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• 2005

The purpose of this study was to analyze characteristics of effective expression on T-shirts pattern by peirce's semiotic theory. The methods of this study was to analyze 721 T-shirts patterns in designer's collection from 2000 to 2004. The results of this study were as follows: First of all, iconic expression showed high frequency after 2000. Characteristics of effective expression were as follows: In geometric expression, repetition was presented as a symbolic sign by regular proportion and rule of dot, line, plane, irregularity, mixture of irregular dot, line, plane. Mixed expression was presented as a iconic and symbolic sign by collage, mixture of dot, line, plane, icon and letter. In iconic expression, simplification of iconic sigrl was presented as a iconic sign by simplification of form, color, texture, realistic expression using digital as a iconic sign, and symbolic face, body as a symbolic sign. Pop art's expression was presented as a iconic sign by a cartoon and commercial character and illusion was presented as a iconic sign. In letter's expression, brand logo was presented as a symbolic sign by transformation of letter's design, a symbolic sign of numeral by transformation of size, thickness, form, color. Symbolic message phrase was presented by slogan, fashion trend, brand image, descriptive indication message as a index sign by using icon or singleness. In conclusion, characteristics of effective expression on T-shirts pattern will present not only the theoretical foundation to raise the value added, but also the information about beauty sense of times, political and social value.

• 한국실내디자인학회논문집
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• 제9호
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• pp.98-107
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• 1996

The purpose of this study is to find out the characteristics of the office space as designed by Gwathemy Siegel and thereby to understand the current trend of interior design of working space in the United States. Unlike most architects, Gwathmey Siegel have extended themselves into interior designing of over twenty offices including law firms, financial institutions and design firms and have successfully won reputation as interior designers. They have distinguished themselves by their ability to turn up and take advantage of the possbility of shaping in a given structure. Their liberal use of fixed furniture and architectural lighting , in addition to ceilings and walls , set them apart from others in the field . The major design elements and principles of Gwathmey Siegel include, among others : 1) Curved and slanted walls on the floor plans endow the office space with forms. Fixed furniture and architectural lighting frequently serve as from -creating elements. 2) The openness of the reception and waiting areas and the irregularity of the corridor walls add a sense of variety in the office. 3) In terms of color and materials, subtle changes of texture and value and the various patterns of joint lines further enrich the space. 4) The principle of symmetry , rough or partial , as applied in the layout of rooms and furniture creates a sense of balance in the space.

• 대한한의진단학회지
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• 제11권2호
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• pp.84-95
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• 2007

Background and Purpose: We have studied the trends of EEG signals in the voluntary breathing condition by applying the fractal analysis. According to chaos theory, irregularity of EEG signals can result from low dimensional deterministic chaos. A principal parameter to quantify the degree of Chaotic nonlinear dynamics is correlation dimension. The aim of this study was to analyze correlation between the correlation dimension of EEG and HRV(heart rate variability). We have studied the trends of EEG signals in the voluntary breathing condition by applying the fractal analysis. Methods: EEG raw data were measured by moving windows during 15 minutes. Then, the correlation dimension(D2) was calculated by each 40-seconds-segment in 15 minutes data, totally 36 segments. 8 channels EEG study on the Fp, F, T, P was carried out in 30 subjects. Results and Conclusion: Correlation analysis of HRV was calculated with deterministic non-linear data and stochastic non-linear data. 1. Ch1(Fp1), Ch4(F3), Ch4(F4) is positive correlated with In LF. 2. Ch1(Fp1), Ch3(F3) is positive correlated with In TF.

• Restorative Dentistry and Endodontics
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• 제17권1호
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• pp.153-165
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• 1992

Dental composite resin is a kind of the particle - reinforced composite material, and is widely used in recent dental restoration of anterior and posterior tooth region. The purpose of this study was to investigate the fracture behaviour according to volume fractions and external findings of the filler particles for better interpretation of the fracture characteristics of posterior dental composite resins by analytic method of fracture mechanics. The plane strain fracture toughness($K_{IC}$) and Acoustic Emission were determined with three - point bending test using the single edge notch specimen according to the ASTM - E399, and its analyzed data was compared with filler volume fractions derived from the standard ashing test and scanning electron fractographs of each specimen including the unfilled experimental resin as a control. The results were that the value of fracture toughness of the composite resin material was in the range from 0.85 MPa$\sqrt{m}$ to 1.60 MPa$\sqrt{m}$ and was higher than the value of the unfilled experimental resin, and the fracture behaviours dervied from Acoustic Emission analysis show prominent differences according to the volume fraction and the size of filler particles used in each composite resin. The degree of resistance against crack propagation seems to be increase and the fractographs demonstrate the high degree of surface roughness and irregularity according with the increase of fracture toughness value.