• Journal of KIISE:Software and Applications
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• v.36 no.3
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• pp.217-225
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• 2009

In case of sketching a conceptual model in 3D space, it's not easy for designer to recognize the depth cue accurately and to draw a model correctly in short time. In this paper, multi-strokes based sketch is adopted not only to reduce the error of input point but to substantiate the shape o) the conceptual design effectively. The designer can see the drawing result immediately after stroking some curves. The shape can also be modified by stroking curves repeatedly and be confirmed the modified shape in real time. However, the multi-strokes based sketch needs to manage the great amount of input data. Therefore, the drawing space is divided into the limited spatial cubical grids and the movable infernal vertex in each spatial grid is implemented and used to define the surface by the multi-strokes. We implemented the spatial sketching system which allows the concept designer's intention to 3D model data efficiently.

• Elastomers and Composites
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• v.49 no.1
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• pp.73-81
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• 2014

Friction and wear behaviors of natural rubber(NR) compounds were investigated using a blade-type abrader. The effects of temperature, normal load, and rotation speed on wear rate were studied, and wear behaviors of deteriorated compounds were also evaluated. As the rotation speed of specimen and the normal load to specimen increased, the wear rate increased. However, as the experimental temperature increased, the frictional coefficient decreased and the wear rate decreased accordingly. It was found from the wear studies that a power-law relation works between the frictional work input and the wear rate. It was observed that the wear rate dramatically increased by the degradation of the rubber specimen. The wear pattern was developed and the bigger ridge space of the pattern was observed usually in the higher normal load applied. In determining the wear rate of rubber compound, the continuous measurements of wear distance using the blade-type abrader could be successfully used instead of intermittent measurements of wear-loss weight.

• Tunnel and Underground Space
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• v.24 no.3
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• pp.212-223
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• 2014

In this study, the stability analyses for metal mine roadways at a great depth were performed. In-situ stress measurements using hydrofracturing, numerous laboratory tests for rock cores and GSI & RMR classifications were conducted in order to find the physical properties of both intact rock and in-situ rock mass distributed in the studied metal mine. Through the scenario analysis and probabilistic assessment on the results of rock mass classification, the in-situ ground conditions of mine roadways were divided into the best, the average and the worst cases, respectively. The roadway stabilities corresponding to the respective conditions were assessed by way of the elasto-plastic analysis. In addition, the appropriate roadway shapes and the support patterns were examined through the numerical analyses considering the blast damaged zone around roadway. It was finally shown to be necessary to reduce the radius of roadway roof curvature and/or to install the crown reinforcement in order to enhance the stability of studied mine roadways.

• The Korean Journal of Applied Statistics
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• v.21 no.5
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• pp.791-799
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• 2008

Ansim Flat DATA Plan is a DATA additional service product related to DATA call in a mobile telephone company A. Up to now, the company A is selling it by outbound TM after targeting customers which used data within specific price band. In this paper, we propose a targeting method applying score model combining response rate and retention rate by data mining. The suggested target model is to find customers more likely not only to respond to outbound TM but also to retain Ansim Flat DATA Plan. The proposed targeting method is expected to improve both from 23.7% to 38.8% in the response rate and from 53.2% to 61.4% in the retention rate.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.7
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• pp.605-613
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• 2013

This research proposes a vibration pattern algorithm to implement the haptic joystick to control a mobile robot at the remote site without watching the navigation environment. When the user cannot watch the navigation environment of the mobile robot, the user may rely on the haptic joystick solely to avoid obstacles and to guide the mobile robot to the target. To generate vibration patterns, there is a vibration motor at the bottom of the joystick which is held by the user to control the motion direction of the mobile robot remotely. When the mobile robot approaches to an obstacle, a pattern of vibration is generated by the motor, and by feeling the vibration pattern which is determined by the relative position of the mobile robot to the obstacle, the user can move the joystick to avoid the collision to the obstacle for the mobile robot. To generate the vibration patterns to convey the relative location of the obstacle near the mobile robot to the user, Fuzzy interferences have been utilized. To measure the distance and location of the obstacle near the mobile robot, ultrasonic sensors with the ring structure have been adopted and they are attached at the front and back sides of the mobile robot. The precise location of the obstacle is obtained by fusing the multiple data from ultrasonic sensors. Effectiveness of the proposed algorithm has been verified through the real experiments and the results are demonstrated.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.4 s.334
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• pp.29-36
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• 2005

Many novel designs of planar antennas for related applications such as internal mobile phone antennas, base station antennas, WLAN or Bluetooth antennas, and so on, have been reported very recently, especially since the year 2000. In this thesis, Dualband internal antenna for GSM/DSC handset is proposed. The antenna has a size of about 38mm$\times$90mm$\times$1mm, giving a total mobile phone PCB for support and fold type Patch of about 30mm$\times$8mm$\times$3.2mm. This antenna characteristic facilitates the fine-tuning of the two operating frequencies of 909MHz and 1762MHz in this dualband design. The measured radiation pattern in the E-plane and H-plane for operating frequencies of 909MHz and 1762MHz is compared and analyzed. The designed and fabricated two band internal antenna for GSM/DSC handset have a gain between 0dBi and 2.0dBi at all bands.

• Journal of Digital Convergence
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• v.16 no.3
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• pp.385-394
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• 2018

The purpose of this study was to examine the effects of hospital organizational culture, organizational silence and job complexity on turnover intention in nurses working in general hospitals. The subjects were 152 nurses working at general hospitals. Data were collected from April 19, 2017 to April 30, 2017, and statistical analysis was analyzed by hierarchical multiple regression analysis using the SPSS/WIN 22.0 program. As a result of the research, turnover intention showed a positive correlation with resignation and defensive silence, whereas there was negative correlation between consensual organizational culture, sacrifice, suitability and connection of job inclination. The factors affecting the turnover intention were the present work experience, defensive silence, sacrifice, and the explanatory power of turnover intention was 47%. Therefore, in order to lower the turnover intention, it will be necessary to provide various programs to change the communication pattern in the nursing organization, and to provide differentiated welfare system.

• Journal of the Korean Geographical Society
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• v.32 no.2
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• pp.217-228
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• 1997

A Study on individual Characteristics and Daily Activities of Housewives in the City of Kwangju. This study examines housewives' daily activities, focusing upon individual characteristics. The data used in this study are based on the fuestionaire survey, asking of personal trip for the weekdays and the weekend. Daily activities are classified into 7 categories and individual characteristics are revealed by age, occupation, a degree of education, number of family, and the residential environment. The results of this study are as follows: 1) The relations between daily activities and individual characteristics are influenced by housewife's occupation. Daily activities of housewives who have jobs are different from those who do not have jobs for a weekday as well as for a weekend. 2) Housewives' daily activities show very busy and vigorous on Saturday. 3) Housewives who are employed are willing to make mutipurpose trips on Saturday. 4) For a weekday, housewives' daily activities are inclined to make one cycle trip in a day, and the more trip cycles are, the more multipurpose trips are made. 5) The relationships between daily activities and individual characteristics show the pattern of WH, WLH, LHLH as it can be grouped.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.9
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• pp.930-935
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• 2009

This paper describes a miniaturezed metamaterial BT chip antenna for mobile devices. The size of the proposed antenna is $3.0\;mm(W){\times}2.0\;mm(L){\times}1.2\;mm(H)$. And it is fabricated by chip type. The zeroth-order resonant properties are analyzed by magnitude and phase distributions of the surface current using surface current scanning system. The antenna offers omni-directional radiation patterns and measured 3D average gain is over - 1.7 dBi.

• Journal of the Korean Institute of Intelligent Systems
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• v.5 no.3
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• pp.117-127
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• 1995

In this paper, we suggest a motion analysis method using ART-I1 competitive learning neural network and fuzzy reasoning by matching the same objects through the consecutive image sequence. we use the size and mean intensity of the region obtained from image segmentation for the region matching by the region and use a ART-I1 competitive learning neural network wh~ch has a learning ability to reflect the topology of the input patterns in order to select characteristic points to describe the shape of a region. Motion vectors for each regions are obtained by matching selected characteristic points. However, the two dimensional image, the projection of the the three dimensional real world, produces fuzziness in motion analysis due to its incompleteness by nature and the error from image segmentation used for extracting information about objects. Therefore, the belief degrees for each regions are calculated using fuzzy reasoning to l-nanipulate uncertainty in motion estimation.