• 대한치과기공학회지
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• 제21권1호
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• pp.55-65
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• 1999

So far, I Conducted an examination with focus on the type, characteristic, and test methods of impact test. which is a type of mechanical that evaluate materials. As mentioned previously, in testing soldering strength of soldering is the load when the object under experiment is broken down with the result of flexibility test or peel test. In this method, a hevay load is necessary until alloy of parent metal is bended, if the alloy of the parent metal has a large mechanical quality(peel strength or resisting power). Once the alloy of the parent metal is bended, however, it tends to come into pieces abruply form the part where soldered. Therefore, a metal has a high breakdown value if the degree of strength of its parent metal is high even if the result of measurement indicates otherwise. Thus, the result of the test did not correspond to the clinical result. Therefore, this study concludes as the following from a test of strength of soldering by mean of conducting an impact test, which is a type of mechanical evaluation methods : 1. Among various impact tests, a charpy thpe is more appropriate than the izod type in testing strength of soldering. 2. As far as test piece is concerned, to use subsized impact test piece is appropriate in the impact test in that it does not have notch. 3. In the matter of analysis, it is appropriate to measure absorbing energy which results from rupture of test piece.

• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.178-183
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• 2020

A series of experiments covering lowest three natural frequencies of rolling coupled pitching were conducted to investigate liquid sloshing with low liquid depth. The test results show that the most violent liquid sloshing in rolling and pitching is located in the vicinity of the first order natural frequency (f1). When the excitation frequency of rolling and pitching is located between 0.98f1 and 1.113f1, roof-bursting phenomenon of liquid appeared, and the maximum impact pressure is at 1.09f1. When the external excitation frequency is at 1.113f1, the number of sloshing shocks decreases sharply. Furthermore, the space distribution of the impact pressure on the left bulkhead and the top bulkhead was analyzed. It is concluded that with low liquid filling, the impact load is greater near the free surface and the top of tank, and the impact position of the side bulkhead increases with the increasing of the frequency near the resonant frequency.

• 디지털융복합연구
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• 제10권8호
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• pp.111-118
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• 2012

본 연구는 한국인의 우쭐 심리적 특성이 명품에 대한 소비자들의 태도에 미치는 영향에 대해 알아보고자 하였다. 선행 문헌분석을 토대로 한국인의 우쭐 심리적 특성에 대해 살펴보았으며, 이러한 한국인의 우쭐 심리적 특성이 명품에 대한 소비자들의 태도와 어떤 관계성이 있는 가를 확인하였다. 연구결과 첫째, 한국인의 우쭐 심리적 특성은 6개의 하위요인으로 나타났다. 둘째, 명품에 대한 소비자들의 태도는 요인분석결과 2개의 요인으로 나타났다. 셋째, 한국인의 우쭐 심리적 특성이 명품에 대한 소비자들의 태도에 미치는 영향을 확인한 결과, 자존감의식성 요인과 거만의식성 요인이 쾌락적 태도에 유의미한 영향을 미치는 것으로 나타났다. 또한, 상대인정성 요인은 품질신뢰 태도에 영향을 미치는 것으로 나타났다. 본 연구결과는 그동안의 명품관련 연구들에서 주로 다루어 왔던 과시적 체면 이라는 심리적 변인에서 탈피하여, 우쭐 이라는 한국인의 또 다른 심리적 특성 변인을 토대로 연구를 진행했다는 점에서 가치가 있으며, 향후 명품광고를 제작하는 실무자에게 타겟 집단의 우쫄 심리적 특성을 고려해야만 하는 시사점을 제공해 주었다.

• 한국농공학회논문집
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• 제56권3호
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• pp.39-45
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• 2014

Dust is mostly caused by human activity. The effect of natural factors on dust emission were studied in many research, but the little effort in researching artificial factors of dust emission. The object of study is to analysis dust emission characteristic by drop impact. Particle matter $10{\mu}m$ ($PM_{10}$) was measured by drop impact on paved soil with changing drop height, weight and drop size. Increasing drop height cause more $PM_{10}$ emission. Increasing drop weight cause more $PM_{10}$ emission but had limit weight for increasing dust emission. Because the exceed kinetic energy of drop weight penetrate the soil surface. The limit perimeter was exist that separating $PM_{10}$ emission aspect. Under limit perimeter, $PM_{10}$ emission was increasing while perimeter was increasing, but over limit perimeter showed the opposite aspect. Regression equations for estimating $PM_{10}$ with kinetic energy and perimeter were made under limit perimeter and over limit perimeter. The $R^2$ of those equations were 0.784, 0.743. The error has occurred between measured $PM_{10}$ and calculated $PM_{10}$ in the equation under limit perimeter. But using equation of case for over limit perimeter, PM10 can be estimated with kinetic energy and drop perimeter.

• 대한조선학회논문집
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• 제54권6호
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• pp.492-500
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• 2017

In the study, numerical simulation on the greenwater impact load of free surface offshore structure in the regular waves using fixed cartesian grid system and Modified Marker-Density (MMD) method were carried out and the results were reviewed. In order to compare numerical simulation and experimental results, the FPSO with the scale ratio of 1/100 model ship with fixed rectangular deck was selected and turbulence characteristic of the flow was considered by applying the Sub-Grid Scale (SGS) in laminar flow. As a result, it is reviewed how the greenwater impact load inflowed from bow in regular headsea wave influence the flow on the deck and the flow characteristic by numerical simulation and the experiment results were compared and reviewed. Based on this study, it would be useful to numerically study the effect of greenwater on offshore structure.

• 한국수자원학회논문집
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• 제43권4호
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• pp.399-408
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• 2010

본 연구에서는 지형학적 분산을 고려한 특성유속에 따른 Nash 모형 매개변수의 민감도 분석을 실시하였다. 또한 이러한 특성유속의 변동에 따른 순간단위도의 형상의 변화를 수치실험을 통해 비교 분석하였다. 대상유역은 보청천 유역 중 본류에 위치하고 있는 4개의 소유역을 선정하였다. 각 대상유역에 대해 지리정보체계를 이용하여 지표면과 하천의 배수경로길이에 대한 평균과 분산을 산정하였다. 산정된 배수경로길이와 특성유속에 의한 Nash 모형 매개변수를 추정하였다. 추정된 매개변수에 의해 순간단위도를 유도하여 형상의 변화를 비교하였다. 이러한 연구를 통해 도출된 주요 결과는 다음과 같다. Nash 모형 매개변수는 지표면 특성유속에 민감하게 반응함을 알 수 있었다. 또한 순간단위도의 감수부의 형상과 첨두유량은 지표면 특성유속에 지배적인 영향을 받으며, 순간단위도의 상승부의 형상과 첨두시간은 하천 특성유속에 지배적인 영향을 받음을 알 수 있었다.

• 대한가정학회지
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• 제34권2호
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• pp.5-30
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• 1996

The purpose of this study is to observe artistic of Expressionism reflected to works of European costume designers by analizing works of seven major representative costume designers in the twentieth century. They are Mariano Fortuny, Paul poiret, Madelene Vionnet, Jean Patou, Jeanne Lanvin, Gabriel Chanel and Elsa Schiaparelli. These designers deployed individual and various creative costume design work with peculiar expresive techniques, which is based on the Expressionism. Although each creative work was made in extremely unique sense, there was comon expressive spirituality I their creative activity. The findings are as follows : 1. Based on the "Medieval-directed characteristic" which arose over all fields of art of those days, a modern and reformative clothing beauty was created by reanalyzing traditional motive. 2 Characteristic of Cubistic Expressionism were described in overall silhouette of clothing and fine decorative element. 3. Fantastic Expressionism, which pursued basic worth from the primitive and ethnic customs, effected costume style of early 20th century and draw such designers as Mariano Fortuny, Leon Bakst, Paul Poiet, Elsa Schiaqarelli to adopt intensive and primary color. And it also gave an impact against traditional concepts by accepting fantastic oriental Exoticism.Exoticism.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.286-287
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• 2012

• Advanced Composite Materials
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• 제16권1호
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• pp.45-61
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• 2007

This paper describes a damage accumulation mechanism in cross-ply CFRP laminates $[0_2/90_2]_{2S}$ subjected to out-of-plane loading. Drop-weight impact and static indentation tests were carried out, and induced damage was observed by ultrasonic C-scan and an optical microscope. Both tests gave essentially the same results for damage modes, sizes, and load-deformation history. First, a crack occurred in the bottom $0^{\circ}$ layer accompanying some delamination along the crack caused by bending stress. Then, transverse cracks occurred in the middle $90^{\circ}$ layer with decreasing contact force between the specimen and the indenter. Measured local strains near the impact point showed that the stress state changed from a bending dominant state to an in-plane tensile dominant state. A cohesive interface element was used to simulate the propagation of multiple delaminations and transverse cracks under static indentation. Two types of analytical models are considered, one with multiple delaminations and the other with both multiple delaminations and transverse cracks. The damage obtained for the model with only multiple delaminations was quite different from that obtained from the experiment. However, the results obtained from the model with both delaminations and transverse cracks well explain the characteristics of the damage obtained in the experiment. The existence of the transverse cracks is essential to form the characteristic impact damage.

• 로봇학회논문지
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• 제10권4호
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• pp.200-212
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• 2015

In classical dynamics, the coefficient of restitution is one of variables to estimate the amount of impulse. In general, we have considered the coefficient of restitution as a constant value. However, coefficient of restitution (COR) is the function of contact material and colliding velocity. Furthermore, COR is also a function of contact area. Thus, without considering the variable characteristic of COR, the actual motion of an object just after impact is not the same as we expect. A general COR model is proposed in this work and its effectiveness is verified through a cart impact experiment and its result is applied to simulation of a ball impact problem. A three-degree-of-freedom manipulator is employed as a test-bed.