• Journal of the Korea Society of Computer and Information
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• v.24 no.4
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• pp.137-144
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• 2019

The purpose of this study was to provide basic data for the development of a prototype of a garment that allows middle aged men to look idealized by examining the type of perception of middle aged men based on their subjective evaluation and their characteristics. This study used the Q methodology, which is a subjective research method that finds correlations among middle aged men across subjective attributes. The types of perception of body shape of middle aged men were analyzed as three types: leaning forward shape with bird legs, developed upper body shape with thick legs, protruding abdomen obesity body shape. The leaning forward shape with bird legs was recognized as the lowest in the BMI index, and the shoulder and chest were sagging, legs were thinner than the body and leaned forward. And that the hip were protruding and had a flat rectangular shape. Developed upper body shape with thick legs was the second overweight type of BMI index. It was recognized that the ankle and calf thighs were thick and the upper abdomen protruded upper body development body. Protruding abdomen obesity body shape was the most obese type with BMI index. In this type, the height was the smallest, and the upper abdomen came out and the abdomen protruded, and the abdomen was more exuded than the chest, and the neck was thick and the hips were recognized as the big body. The middle aged men's recognitive body shape was classified as a similar to actual body shape. However, in the recognition type, the frontal and side body types were mixed and classified. It is necessary to study the ergonomic pattern considering the features of each body type. This suggests that psychological effects can be obtained that allow the body shape that changes with age to be accepted more positively.

• Journal of the Korean Ceramic Society
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• v.23 no.1
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• pp.44-50
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• 1986

Si-ZnO n-n heterojunction diodes were prespared by r.f diode sputtering of the sintered ZnO target on n-type Si single crystal wafers and their structures and electrical properties were studied. The films were grown orientedly with the c-axis of crystallites perpendicular to the substrate surface at low r.f. powder and grown to polycrystalline films with random orientation at high r. f. powder. The crystallite size increased with the increasing substrate temperture The oriented texture films only were used to prepare the photovoltaic diodes and these didoes showed the photovoltaic effect veing positive of the ZnO side for the photons in the wavelength range of 380-1450nm. The sign reversal of phootovoltage which is the property os isotype heterojunction was not observed because of the degeneration of the ZnO films. The diode showed the forward rectification when it was biased with the ZnO side positive. The current-voltage characteristics exhibited the thermal-current type relationship J∝exp(qV/nkT) with n=1.23 at the low forward bias voltage and the tunnelling-current type relationship J∝exp($\alpha$V) where $\alpha$ was constant independent of temperature at the high forward bias voltage. The crystallite size of ZnO films were influenced largely on the photovoltaic properties of diodes ; The diodes with the films of the larger crystallites showed the poor photovoltaic properties. This reason may be cosidered that the ZnO films with the large crystallites could not grow to the electrically continuous films because the thickness of films was so thin in this experiment.

• Structural Engineering and Mechanics
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• v.46 no.5
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• pp.673-693
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• 2013

This paper presents a systematic design and training procedure for the feed-forward back-propagation neural network (NN) modeling of both forward and inverse behavior of a rotary magnetorheological (MR) damper based on experimental data. For the forward damper model, with damper force as output, an optimization procedure demonstrates accurate training of the NN architecture with only current and velocity as input states. For the inverse damper model, with current as output, the absolute value of velocity and force are used as input states to avoid negative current spikes when tracking a desired damper force. The forward and inverse damper models are trained and validated experimentally, combining a limited number of harmonic displacement records, and constant and half-sinusoidal current records. In general the validation shows accurate results for both forward and inverse damper models, where the observed modeling errors for the inverse model can be related to knocking effects in the measured force due to the bearing plays between hydraulic piston and MR damper rod. Finally, the validated models are used to emulate pure viscous damping. Comparison of numerical and experimental results demonstrates good agreement in the post-yield region of the MR damper, while the main error of the inverse NN occurs in the pre-yield region where the inverse NN overestimates the current to track the desired viscous force.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.5 s.98
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• pp.200-208
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• 1999

The statics relation of the Stewart platform has been investigated from the viewpoint of the forward and inverse force transmission analyses. Two eigenvalue problems corresponding to the forward and inverse force transmission analyses have been formulated. The forward force transmission analysis is to determine the ranges of the magnitudes of the force and moment generated at the end-effector for the given magnitude of linear actuator forces. In reverse order, the inverse force transmission analysis is to find the range of the magnitude of actuator forces for the given ranges of the magnitudes of the force and moment at the end-effector. The inverse force transmission analysis is important since it can provide a designer with a valuable information about how to choose the linear actuators. It has been proved that two eigenvalue problems have a reciprocal relation, which implies that solving either of the eigenvalue problems may complete the forward/inverse force transmission analysis. A numerical example has been also presented.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.7
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• pp.559-567
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• 2000

This paper proposes simple and practical methods in order to overcome complex formulation and heavy computational burden of the forward kinematics of 6 앨 3-6 type parallel manipulators. Three ap-proaches for the forward kinematics are presented : one extra sensor a modified structure and novel numerical method. The proposed methods are applied to the forward kinematics of a new 6 앨 parallel manipulator with special geometry that has three internal links three external links and a moving platform of a cone shape. The proposed methods use three tetrahedrons for finding the position and orientation vector of the moving platform. The main advantages of the appraches using tetrahedrons are to abbreviate the formulation to easily find so-lutions of the forward kinematics and to be able to practically control of the manipulator in real time.

• Journal of the Korean Society of Clothing and Textiles
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• v.19 no.6
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• pp.1027-1039
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• 1995

Clothing fitness is strongly required in the apparel industry, and draping is an effective tool to increase fitness to the wearers. A more sophisticated and systematic information of the somatotype, accordingly, is necessary for better cress form design. This study was performed to provide fundamental data on middle aged women's upper torso for dress form designers and pattern makers by classifying the somatotype based on each individual's lateral view, and analyzing the characteristics of their somatotype. Data were analyzed by factor analysis, cluster analysis, analysis of variance. Factor analysis was used to 23 items from photometric measurment and cluster analysis was applied for classification of upper torso forms. Through cluster analysis using 5 factor scores, 3 somatotypes were categorized from th lateral view 1) Type I was straight somatotype in which the plumb line passes throught the lobe of the ear, the shoulder joing and the mid abdominal region laterally. This type of woman was slender and shorter than average. 2) Type II was bending somatotype in which the upper portion of upper torso is bent forward. This type of woman was taller and fatter than average. 3) Type III was swayback somatotype in which the upper portion of protruding point on the back is bent forward but the lower portion of protruding point had characteristic of turning over somatotype. This type of woman had storter length on the front and longer lenght on the back, slender type and flat chest.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2020-2022
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• 1997

An active clamp forward converter is proper for minimization and basically makes high efficiency of the system because of soft switching type. Especially, when applied to forward converter, it widens the control range of duty ratio and is suitable for high input voltage. In other hand, the current doubler has high utility efficiency of transformer and reduces output current ripple because it always transfers the power through the transformer and has two inductor with opposite slope. So, this paper explained the conduction mode of an active clamp forward converter with the current doubler rectifier.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.224-228
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• 2000

In this paper, the kinematics of the new type of parallel manipulator is studied, and neural network is applied to solve the forward kinematics problem. The parallel manipulator, called a Stewart platform, has an easy and unique solution about the inverse kinematics, however the forward kinematics is difficult to get the solution because of the lack of an efficient algorithm due to its highly nonlinearity. This paper proposes the neural network scheme as an alternative Newton-Raphson method. The neural network is found to improve its accuracy by adjusting the offset of the result obtained.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.636-641
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• 1998

In this paper, operation characteristics of the Zero-voltage-Switching(ZVS) mode and Non-Zero-Voltage-Switching (NZVS) mode of the active clamp (ACL) forward converter are compared through the loss analysis. The losses of semiconductor devices, transformer and passive elements of the converter are analyzed and compared for each type of operation mode. In order to verify the validity of the analysis, we have built a 50W ACL forward converter and measured the losses of the converter. From the experiment it is known that the ACL forward converter shows nearly same loss distribution for both of operation modes

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.650-654
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• 2005

Computational and experimental studies on the forward-sweep inducer for the rocket-engine turbopump are presented in comparison with the conventional backward-sweep inducer. It is shown that back flows at the inlet decreases for forward-sweep inducers. And the low pressure region at the back flow are also decreased, which is assumed to promote the suction performance of the inducers. The backward-sweep inducer shows almost the same suction performance as that of the backward-sweep inducers although it has small inlet tip diameter and shorter length. And the efficiency of the forward-type inducer shows better results than the backward-sweep inducer due to the small size of backflows.