• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.771-776
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• 2002

Optimal shape of the NFR suspension is studied and developed to improve the dynamic performance and reduce the vibration of the suspension system including a optical head slider. Since accurate position control and stability of the slider motion are highly required in NFR due to the narrower track width and the heavier slider than HDD slider with the low flying height, the dynamic characteristics of the suspension are very important to the mechanical performance of the system. The first natural frequencies in flexural and lateral motion of the suspension are critical factors affecting the dynamics and stability of the flying head, so that the dynamic parameters should be designed properly to avoid an excessive vibration or a crash of the slider on the disk. This paper optimizes the shape of the suspension based on homogenization method in NASTRAN and develops a new suspension shape for NFR system. The suspension is tested on experiment to verify the improvement of the dynamic characteristics.

• Tribology and Lubricants
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• 제23권1호
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• pp.29-36
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• 2007

It necessarily follows that wear particles are generated through a friction and wear in a mechanical moving system. The wear particles are relative to the failure and the life of machine elements directly. To analyze the wear particle, its shape characteristics were calculated quantitative values such as diameter, roundness and fractal parameters by digital image processing. In this study, the histograms of shape parameters of wear particles were used for the purpose of analyzing the distribution of wear particles in various conditions. We consider that the histogram of shape parameter can be effectively represented to study a wear mechanism.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.735-738
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• 1997

The aerodynamic charateristics of high speed train can be improved by fore-body design. In this paper, the design a fore-body shape which has optimal aerodynamic charateristics, 6 models of fore-body shape are proposed and the change of aerodynamic characteristics is studied through calculations of flow field around high speed train fro each fore-body shape. The flow field around high speed trains are calculated using Navier-Stokes equation. The variational trends of aerodynamic characteristics are studied from the result of flow calculation around high speed trains for 6 fore-body shapes.

• 소음진동
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• 제5권2호
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• pp.215-224
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• 1995

In this paper, the three-dimensional finite element model is established to investigate the structural dynamic characteristics of rotor blade using a finite element analysis. Six natural frequencies and mode shapes are calculated by computer simulation. The first three flapping modal frequencies, the first two lead-lag modal frequencies, and the first feathering modal frequency are validated through comparison with the modal test results of the fixed rotor blade. The computer simulation results are found in good agreement with experimentally measured natural frequencies. The important results are obtained as follows: (1) Natural frequencies are changed due to the variation of rotational speed and fiber angle of rotor blade, (2) Weak coupling between flapping mode shape and lead-lag mode shape are detected, (3) Centrifugal force has more effect on flapping modal frequency than lead-lag modal frequency.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 1995년도 추계 학술대회논문집
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• pp.49-54
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• 1995

A numerical analysis on the effect of the front shape on the aerodynamic characteristics of HST model is made, using FVM based general purpose 3D Navier-Stokes eq. solver, TURBO-3D program. Numerical solutions are compared with each case of different front shape for HST model. The result shows a good quantitative aerodynamic characteristic tendencies for variation of front shape of HST. Thus it may be used as a basis in the design of the shape of real HST.

• 복식
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• 제40권
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• pp.81-93
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• 1998

It is necessary to research shape of the breast of girls at adolescence for developing well-fit brassiers. 313 participants reside in Chonju and Kunsan were gathered for body measurement. The conclusion of this study can be summarized as follows. 1) The Analysis of Body Shape by Measurement. Comparing Age GroupⅠ(aged 10 to 12)' measurement with Age GroupⅡ(aged 13 to 15)', Each items has statistical significance. Two groups differed in the length, girth, depth, width items. 2) Factor Analysis of Body Measurement (1) Age GroupⅠ'characteristics were categorized Three Factor : Breast size and breast apex length. Breast volume, Length of the Breast part. (2) Age GroupⅡ' characteristics consist of four factors, which are named as breast size and its jut (first factor), breast volume (second factor), contour of breast profile & its jut (third factor), shoulder length (fourth factor). 3) Characteristics of Breast Shape. (1) Breast shapes of Age GroupⅠ are classified into three types. Types 1 is a protruded and more voluminous shape. Type 2 is the most voluminous and breast fatness is highest. Type 3 is the smallest and flat shape growing now. (2) Breast shapes of Age GroupⅡ are also classified into three types. Type 1 is the longest in length and middle in fatness, voluminous in size. Type 2 is the smallest in stature and the slimmest in fatness in breast shape. Type 3 is middle in length, the fattest and the most voluminous in breast.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
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• pp.75-79
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• 2001

In the recent years, as the research and the development of micro and precision machinery become active, the interest of micro actuators using SMA(Shape Memory Alloy) has been increased. The dynamic characteristic analysis of SMA is necessary for actuator application and many common researches report the material characteristics of SMA sufficiently. However, the research on dynamic characteristics is very deficient. In this paper, the helical spring are fabricated with NiTi SMA wire of high resistivity, The force, response speed, temperature, and displacement are measured by digital force gauge, infrared thermometer, and laser displacement sensor so that the dynamic characteristics of this SMA is analyzed. Also, bidirectional actuator was fabricated and experimented for its performance.

• Journal of Advanced Marine Engineering and Technology
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• 제30권8호
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• pp.877-884
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• 2006

The objective of this study is to investigate the aerodynamic characteristics of a vertical axis wind turbine blade as the basic study of a design of a vertical axis wind turbine. The lift and drag coefficients of the various shape of the vortical axis wind turbine blades are analyzed and compared using the CFD code Fluent. To validate the numerical analysis, the predicted results of the Fluent are compared with those of the Xfoil code and the experimental results. We conclude that the program Fluent can be used to predict the aerodynamics of the wind turbine blade. By comparing the predicted results of the aerodynamic characteristics of the different shape of the blades, an appropriate shape of the blade is suggested to design the vortical axis wind turbine blade.

• 대한기계학회논문집A
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• 제32권11호
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• pp.963-969
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• 2008

The wear particles are relative to the failure and the life of machine elements directly. But it is not laid down to calculate shape parameters of wear particle. To analyze a variation of distributed characteristics of wear particles on moving conditions, its shape parameters such as diameter and roundness were calculated the quantitative values by digital image processing, and had to be defined the effective method of using those data. Up to the present, the shape parameters have been used simply into the average values. But these values are not effective to analyze a variation of distributed characteristics of occurred wear particles on moving conditions. In this study, the relative histograms of shape parameters of wear particles were used for the purpose of analyzing the distribution of wear particles in various conditions. The results showed that the relative histogram of shape parameters can be effectively represented to study a wear mechanism.

• 한국의류산업학회지
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• 제22권1호
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• pp.87-93
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• 2020

This study provide basic data to develop a dress form reflecting body shape characteristics by age and to produce a 3D body form in a virtual fitting program. A comparative analysis was conducted on the size, section shape, and slope of side shape of the modeling form by the sizing of the basic female avatar in CLO 3D, one of the 3D apparel CAD programs and the body form of women in their 20s-50s by body shape in the 6th Size Korea (2010). First, all the differences were formed similarly in the direct measurements between the 3D avatar and the body form were within 1 mm. Second, in a comparison of the section form of the avatar and body form in Size Korea, the avatar was formed in straight body shape and did not reflect a spinal curvature according to age. As a result of an examination of the items with a difference over 5° in the slope of side shape, there were angle differences in numerous body shapes in the angles of the side upper abdomen, side upper back, and side upper bust, and the avatar's bust shape was expressed more flatly compared to body form. It will be possible to produce an avatar that can adequately reflect body shape characteristics by adding detailed length and angle items by the region like waist back length and front length in producing the avatar reflecting body shape characteristics, instead of a standard body shape.