• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.455-462
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• 2016

Recently, followed by rapid growth of robotics field, multi-linkage mechanism which can even pass by rough road is getting lots of attention. In this paper, I focused on Jansen mechanism. It's a kinematics object which is named after Dutch artist Theo jansen. Jansen mechanism embraces structure and mechanism which creates locomotion with the combination of the power and simple structure. Theo jansen suggests a 'Holy number'. It's an ideal ratio of leg components length. However, if there's desired gait locomotion, you have to adjust the ratio and the length. But even slight change of the length could cause a big change at the end-point. To solve this problem, I suggest a reverse engineering method to get a ratio of each links by nonlinear optimization with pre-set desired trajectory. First, we converted a movement of the joint of Jansen mechanism to vectors by kinematics analysis of multi-linkage structure. And we showed the trajectory at the end-point. After that, we set desired trajectory which we found most ideal. Then we got the length of the leg components which draws a trajectory as same as trajectory we set, using Multi-objective genetic algorithm toolbox in MATLAB. Result is verified by Edison designer and mSketch. And we analyzed if it could pass through the obstruction which is set dynamically.

• Journal of the Korean Society of Clothing and Textiles
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• v.20 no.4
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• pp.631-646
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• 1996

The purpose of this study was to investigate the difference of visual evaluation about silhouette image. The specific objective were; 1) to construct of silhouette image evaluation instrument using semantic differential scale for the purpose of measuring the width and length; 2) to identify the factor structure of the silhouette; 3) to test the difference of visual perception to the silhouette as the variation of width; 4) to test the difference of visual perception to the silhouette as the variation of length; 5) to test interaction effect between width and length. The major finding were; For the visual evaluation of silhouette as shoulder width variatiorl, there were significant difference in hardness and softness factor. For the hard and soft image, we should express by variation of the shoulder width. For the visual evaluation of silhouette as skirt width variation, there were significant difference in attention factor. For the attensive image, we should express by variation of the skirt width. For the visual evaluation of silhouette as skirt length variation, there were significant difference in activity factor. For the active image, we should express by variation of the skirt length.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.490-493
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• 2002

In this study, we have investigated optimum value for side gate length and side gate voltage of double gate (DG) MOSFET with main gate and side gate. We know that optimum side gate voltage for each side length is about 3V. Also, we know that optimum side gate length for each main gate length is about 70nm. We have presented the transconductance and subthreshold slope for each side gate length. We have simulated using ISE-TCAD tool for characteristics analysis of device.

• Journal of IKEEE
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• v.27 no.4
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• pp.399-404
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• 2023

In this paper, we analyzed the current path in the O/N/O (Oxide/Nitride/Oxide) structure of 3D NAND Flash memory and in the O/N/F (Oxide/Nitride/Ferroelectric) structure where the blocking oxide is replaced by a ferroelectric. In the O/N/O structure, when V_read is applied, a current path is formed on the backside of the channel due to the E-fields of neighboring cells. In contrast, the O/N/F structure exhibits a current path formed on the front side due to the polarization of the ferroelectric material, causing electrons to move toward the channel front. Additionally, we performed an examination of device characteristics considering channel thickness and channel length. The analysis results showed that the front electron current density in the O/N/F structure increased by 2.8 times compared to the O/N/O structure, and the front electron current density ratio of the O/N/F structure was 17.7% higher. Therefore, the front current path is formed more effectively in the O/N/F structure than in the O/N/O structure.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2142-2147
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• 2007

Experimental study was conducted to evaluate the performance of a miniature loop heat pipe (MLHP) with non-inverted meniscus type capillary structure. All parts of MLHP in this study were made of copper including the capillary structure and the distilled water was used as a working fluid of MLHP. The outer diameter of evaporator was 9 mm and its length was 119 mm. The effective pore size of the capillary structure was 30 micron and its porosity was 60%. The vapor transport line, the liquid transport line and the condenser were consisted of single 4.0 mm copper tube. The distance between the evaporator and the condenser region was 200 mm and the length of the loop was 969 mm. This MLHP was operated successfully at any orientation but the gravity highly influenced the thermal performance of the MLHP. The maximum thermal load was 130 watts at the bottom heat mode and the 20 watts at the top heat mode.

• Applied Biological Chemistry
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• v.37 no.2
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• pp.94-99
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• 1994

Bran structure and water uptake rate for brown rices of thirteen japonica and twelve Tongil cultivars were investigated. The japonica type was shorter in length and had lower value in the ratio of length to width than Tongil one. No differences were observed in width and weight between the two types. The number of aleurone layer and the thickness of bran layer were higher in dorsal side than in ventral side in all rice cultivars. The structure in ventral side was similar but the number of aleurone layer in dosal side was higher in japonica samples. There were no significant differences in water uptake rates showed no correlation with the bran structure.

• Computers and Concrete
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• v.27 no.4
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• pp.385-393
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• 2021

Reinforcement corrosion is the main cause of the durability failure of reinforced concrete (RC) structure. In this paper, a three-dimensional (3D) numerical model of macro-cell corrosion is established to reveal the corrosion mechanisms of steel reinforcement in RC structure. Modified Direct Iteration Method (MDIM) is employed to solve the system of partial differential equations for reinforcement corrosion. Through the sensitivity analysis of electrochemical parameters, it is found that the average corrosion current density is more sensitive to the change of cathodic Tafel slope and anodic equilibrium potential, compared with the other electrochemical parameters. Furthermore, both the anode-to-cathode (A/C) ratio and the anodic length have significant influences on the average corrosion current density, especially when A/C ratio is less than 0.5 and anodic length is less than 35 mm. More importantly, it is demonstrated that the corrosion rate of semi-circumferential corrosion is much larger than that of circumferential corrosion for the same A/C ratio value. The simulation results can give a unique insight into understanding the detailed electrochemical corrosion processes of steel reinforcement in RC structure for application in service life prediction of RC structures in actual civil engineer.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.3
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• pp.93-104
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• 2018

This study is about occurrence pattern of vacant spaces as a urban decline indicator to consider a decline of old hillside residential area from spatial structure perspective. For investigation based upon vacant space and the street structure, this study selects Ami Chojang-dong in Seo-gu, Busan, of which 79.7% of total area is over a gradient of $10^{\circ}$. Focused on relationship between occurrence pattern of vacant spaces and 'vertical alleys(link)' serving as main movement path of local residents in hillside residential area, the length, numbers, slopes, and use characteristic of vertical alleys were analyzed using Arc GIS 9.3 program to classify characteristic zone types of spacial structure in hillside residential area. After the occurrence pattern of vacant space are interpreted in relation with building density, vertical alleys' number length slope, the social and economic issues have been considered as well. After analyzing the occurrence pattern of vacant space, this study argues that the occurrence pattern of vacant space in old hillside residential area is rather affected by street structure system consisting of vertical alleys than the impacts of social economical issues.

• Coupled systems mechanics
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• v.12 no.5
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• pp.409-418
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• 2023

A coupled algorithm is proposed which first considers the creation of porous structure of the material and then the simulations of response of mechanical components with porous structure to a variable load history. The simulations are carried out by the Prandtl operator approach in the finite element method (FEM) which enables structural simulations of mechanical components subjected to variable thermomechanical loads. Temperature-dependent material properties and multilinear kinematic hardening of the material can be taken into account by this approach. Several simulations are then performed for a tensile-compressive specimen made of a generic porous structure and mechanical properties of Aluminium alloy AlSi9Cu3. Variable mechanical load history has been applied to the specimens under constant temperature conditions. Comparison of the simulation results shows a considerable elastoplastic stress-strain response in the vicinity of pores whilst the surface of the gauge-length of the specimen remains in the elastic region of the material. Moreover, the distribution of the pore sizes seems more influential to the stress-strain field during the loading than their radial position in the gauge-length.

• Earthquakes and Structures
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• v.19 no.1
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• pp.17-28
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• 2020

In this paper, a modified and improved seismic isolation system called suspension columns for seismic isolation was investigated. An experimental study of the proposed isolation method, together with theoretical and numerical analyses, has thoroughly been conducted. In the proposed method, during the construction of the foundation, some cavities are created at the position of the columns inside the foundation and the columns are placed inside the cavities and hanged from the foundation by flexible cables rather being directly connected to the foundation. Since the columns are suspended and due to the gap between the columns and walls of the cavities, the structure is able to move freely to each side thus, the transmitted seismic actions are reduced. The main parameter of this isolation technique is the length of the suspension cable. As the cable length is changed, the natural frequency of the structure is also changed, thus, the desired frequency can be achieved by means of an appropriate cable length. As the experimental phase of the study, a steel frame structure with two floors was constructed and subjected to the acceleration of three earthquakes using a shaking table with different hanging cable lengths. The structural responses were recorded in terms of acceleration and relative displacement. The experimental results were compared to the theoretical and numerical ones, obtained from the MATLAB programming and the finite element software ABAQUS, showing a suitable agreement between them. The results confirm the effectiveness of the proposed isolation method in reducing the seismic effects on the structure.