• 한국정밀공학회지
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• 제23권1호
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• pp.56-63
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• 2006

The aim of this study is to find the best cutting conditions as analyzing cutting process of paper shredder and shape of cutter. The test has been done variation of torque and cutting velocity according to load. When shape of cutter and distance between cutter and shaft are changed, The variation of cutting force according to cutting angle and load is geometrically analyzed. The result of geometrical analysis is presented that the radius and array of cutter is the method to improve torque of paper shredder. In this paper it is presented as basic method of design to improve cutting performance of paper shredder.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 1996년도 제6회 학술강연회논문집
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• pp.209-216
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• 1996

The shape variation of billet was investigated by numerical method and spray forming work with variation of average substrate withdrawal velocity$\bar{V}$, withdrawal velocity change interval $\Delta$t and velocity deviation from average velocity $V_{dev}$. The shape and diameter with large$\bar{V}$, $\Delta$t, $V_{dev}$ vary seriously. When $\bar{V}$, $\Delta$t, $V_{dev}$ are smaller, the shape of billet is more simillar to that of the billet with constant withdrawal velocity. The average diameter of billet is determined by only $\bar{V}$, independent of $\Delta$t, $V_{dev}$. With $\bar{V}$, : 0.2 mm/sec $\Delta$t: 200 sec and $V_{dev}$. : 0.2mm/sec billet of constant diameter 230mm$\times$ height 1000mm were manufactured.

• Smart Structures and Systems
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• 제2권4호
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• pp.357-363
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• 2006

Equations describing deformation defects, damage accumulation, and fracture condition have been suggested. Analytical and numerical solutions have been obtained for defects produced by a shear in a fixed direction. Under cyclic loading the number of cycles to failure well fits the empirical Koffin-Manson law. The developed model is expanded to the case of the micro-plastic deformation, which accompanies martensite accommodation in shape memory alloys. Damage of a shape memory specimen has been calculated for two regimes of loading: a constant stress and cyclic variation of temperature across the interval of martensitic transformations, and at a constant temperature corresponding to the pseudoelastic state and cyclic variation of stress. The obtained results are in a good qualitative agreement with available experimental data.

• 대한기계학회논문집A
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• 제38권10호
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• pp.1139-1145
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• 2014

인체 골격의 모델생성과 형상변동을 파악하는 것은 생체역학의 응용분야에서 중요한 부분을 차지한다. 본 논문에서는 3 차원 대퇴골 모델의 데이터베이스로부터 대퇴골의 형상변동을 통계적으로 분석하고, 추출된 주요 파라미터를 사용하여 대퇴골의 형상을 직관적으로 모델링 할 수 있는 방법을 제안한다. 이를 위해서 먼저 통계적 기법 중에 하나인 주성분 분석(PCA)을 이용하여 대퇴골의 형상변동을 파악하였다. 주성분 분석을 수행하기 위해서는 3 차원 대퇴골 모델 간에 토폴로지(Topology)의 일치가 필요하다. 따라서 대퇴골의 형상에 해부학적 기준점(Landmark)을 정의하여 템플릿 모델이 대상 대퇴골 모델로 변형되기 위한 방향을 결정한 후 곡면 피팅(Surface fitting)을 수행하였다. 다음으로 주성분 분석을 통해 도출된 주성분과 대퇴골의 형상을 대표할 수 있는 해부학적 파라미터와의 상관관계를 정의하였다. 마지막으로 해부학적 파라미터로 대퇴골 모델의 생성 및 형상변동을 가시화 할 수 있는 프로그램을 개발하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1990년도 가을 학술발표회 논문집
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• pp.113-116
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• 1990

This study is designed to analyze the variation of grading and shape of aggregate with the number of rotations of Los-Angeles abrasion machine, and is aimed to analyze the effect of slump and compressive strength of strength of concrete with the shape of coarse aggregate by the abrasion act.

• 복식문화연구
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• 제29권3호
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• pp.388-405
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• 2021

This study classifies the compositional methods of power shoulder jackets from 1980 to the present. It analyzes the relevance of jacket details according to how the power shoulder changes and its compositional methods by era. The research subdivides shoulder compositional techniques into seven, based on shoulder variation, sleeve variation, and the body and sleeve combination. The researcher investigates the frequency and trends of composing shoulders and analyzes details pertaining to the silhouette, jacket length, collar shape, and front closure. The most common method of shoulder composition is an angular shoulder variation. The others are a rounded shoulder variation, puffed sleeve, sleeve variation using pattern incision, raglan and kimono sleeves, and a shoulder variation that expanded the angle and width. The frequency differs slightly for each era. The relationship between shoulder compositional methods and details of power shoulder jackets is statistically significant, showing period-related differences. The homogeneity analysis results reveal that the shoulder composition of power shoulder jackets, the times, and details fall into distinct groups. This analysis shows that the silhouette, length, collar, and front closure of the power shoulder jacket differ depending on the power shoulder's compositional methods. Moreover, the shape of the power shoulder jacket is distinctly different. One can use this data to help develop the power shoulder jacket design by reflecting the details of shoulder compositional methods and changing trends over time.

• 대한기계학회논문집A
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• 제30권2호
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• pp.149-156
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• 2006

A boundary-based design sensitivity analysis(DSA) technique is proposed for addressing shape optimization issues in the elastostatics problems. Sensitivity formula is derived based on the continuum formulation in a boundary integral form, which consists of the boundary solutions and shape variation vectors. Though the boundary element method(BEM) has been mainly used to obtain the boundary solution, the FEM is used in this paper because this is much more popular, and has greatly improved meshing and computing power recently. The advantage of the boundary DSA is that the shape variation vectors, which are also known as design velocity fields, are needed only on the boundary. Then, the step for determining the design velocity field over the whole domain, which was necessary in the domain-based DSA, is eliminated, making the process easy to implement and efficient. Problem of fillet design is chosen to illustrate the efficiency of the proposed method. Accuracy of the sensitivity is good with this method even by employing the free mesh for the FE analysis.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제16권11호
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• pp.1096-1100
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• 2010

본 논문에서는 MR 영상에서 중간형상정보를 이용한 활성형상모델 기반의 반월상 연골 자동 분할 기법을 제안한다. 첫째, 훈련집합 내의 형상 변형을 반영하기 위해 반월상 연골 통계형상모델을 생성한다. 둘째, 큰 변형을 갖는 반월상 연골의 견고한 분할을 위해 유사도에 따른 가중치 기법을 이용하여 중간형상정보 생성 기법을 제안한다. 마지막으로 활성형상모탤 적합을 통해 반월상 연골 자동 분할을 수행한다. 제안 방법의 평가를 위하여 육안평가와 정확성 평가 그리고 수행시간을 측정하였다. 정확성 평가는 자동 분할과 반자동 분할 결과간의 평균거리차이를 측정하였고 이를 컬러맵으로 표현하였다. 실험 결과 평균거리차이는 내측 반월상 연골은 $0.54{\pm}0.16mm$, 외측 반월상 연골은 $0.73{\pm}0.39mm$으로 측정되었고, 수행시간은 평균 4.87초로 측정되었다.

• 대한치과교정학회지
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• 제53권3호
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• pp.185-193
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• 2023

Objective: The growth and development of the mandible strongly depend on modeling changes occurring at its ramus. Here, we investigated covariance patterns between the morphology of the ramus and the rest of the face. Methods: Lateral cephalograms of 159 adults (55 males and 104 females) with no history of orthodontic treatment were collected. Geometric morphometrics with sliding semi-landmarks was used. The covariance between the ramus and face was investigated using a two-block partial least squares analysis (PLS). Sexual dimorphism and allometry were also assessed. Results: Differences in the divergence of the face and anteroposterior relationship of the jaws accounted for 24.1% and 21.6% of shape variation in the sample, respectively. Shape variation was greater in the sagittal plane for males than for females (30.7% vs. 17.4%), whereas variation in the vertical plane was similar for both sexes (23.7% for males and 25.4% for females). Size-related allometric differences between the sexes accounted for the shape variation to a maximum of 6% regarding the face. Regarding the covariation between the shapes of the ramus and the rest of the face, wider and shorter rami were associated with a decreased lower anterior facial height as well as a prognathic mandible and maxilla (PLS 1, 45.5% of the covariance). Additionally, a more posteriorly inclined ramus in the lower region was correlated with a Class II pattern and flat mandibular plane. Conclusions: The width, height, and inclination of the ramus were correlated with facial shape changes in the vertical and sagittal planes.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 추계학술대회 논문집
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• pp.245-249
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• 2009

According to the increase of intelligent vehicles many automotive electric components are installed. The wire harness which connects those also increases. The crimping process for compressing the copper wire bundle into the terminal is a key process to assure the good quality of wire harness. For the case of inadequate forming condition many shape failures such as less-filling, over-filling are happen in the crimping process. Even though the quality of crimping shape is satisfactory the quality check for electrical resistance of wire harness is sometime not satisfied the qualification due to large variation of electrical resistance of wire harness under climate test. This large variation is thought to be related with the malfunction automotive electric system and caused by the internal stress of wire, which occurred during the crimping process. In this paper we develop the 3D-FEM simulation scheme and design methodology of optimum terminal shape. Also the effect of terminal shape on the residual stress is discussed.