• Journal of KIISE:Software and Applications
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• v.36 no.2
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• pp.161-168
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• 2009

In this paper, we develop an Intelligent Wheelchair(IW) control system for the people with various disabilities. The aim of the proposed system is to increase the mobility of severely handicapped people by providing an adaptable and effective interface for a power wheelchair. To facilitate a wide variety of user abilities, the proposed system involves the use of face-inclination and mouth-shape information, where the direction of an Intelligent Wheelchair(IW) is determined by the inclination of the user's face, while proceeding and stopping are determined by the shape of the user's mouth. To analyze these gestures, our system consists of facial feature detector, facial feature recognizer, and converter. In the stage of facial feature detector, the facial region of the intended user is first obtained using Adaboost, thereafter the mouth region detected based on edge information. The extracted features are sent to the facial feature recognizer, which recognize the face inclination and mouth shape using statistical analysis and K-means clustering, respectively. These recognition results are then delivered to a converter to control the wheelchair. When assessing the effectiveness of the proposed system with 34 users unable to utilize a standard joystick, the results showed that the proposed system provided a friendly and convenient interface.

• Journal of Navigation and Port Research
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• v.29 no.6 s.102
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• pp.515-522
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• 2005

The ship plating is generally subjected to. combined in-plane load and lateral pressure loads, In-plane loads include axial load and edge shear, which are mainly induced by overall hull girder bending and torsion of the vessel. Lateral pressure is due to. water pressure and cargo. These load components are nat always applied simultaneously, but mare than one can normally exist and interact. Hence, far mare rational and safe design of ship structures, it is af crucial importance to. better understand the interaction relationship af the buckling and ultimate strength far ship plating under combined loads. Actual ship plates are subjected to relatively small water pressure except far the impact load due to. slamming and panting etc. The present paper describes an accurate and fast procedure for analyzing the elastic-plastic large deflection behavior up to. the ultimate limit state of ship plates under combined loads. In this paper, the ultimate strength characteristics of plates under axial compressive loads and lateral pressure loads are investigated through ANSYS elastic-plastic large deflection finite element analysis with varying lateral pressure load level.

• Journal of Technology Innovation
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• v.25 no.4
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• pp.285-311
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• 2017

PSL-II Accelerator is a large-scale research facility located in Pohang, which was established in 1988 and operated since 1995. It is a program to be promoted to contribute to basic science research in Korea by applying it to cutting-edge research in the field of basic and applied science. It is estimated that around KRW 787.9 billion was invested for construction and operation in the near-30-year period until 2016. Although there have been various evaluations of the need, importance and effectiveness of accelerator in relation to the accelerator policy, most of them emphasize the successful outcome of the present time and suggest the government's need for sustained support in the future or suggest policy implications for improving the policy in a comprehensive manner. And there was no systematic analysis of the results on a comprehensive review or the various policy evaluations of the accelerator policy. In this study, three stages of PSL-II accelerator program were evaluated, and five main criteria of policy activity were considered. The purpose of this study is to suggest the policy implications related to the principles of policy activity which is essential in construction and operation of similar large-scale research facilities in addition to PSL-II accelerator.

• Korean Journal of Materials Research
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• v.8 no.7
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• pp.634-640
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• 1998

A well- shaped trench was investigated in view of the defect distribution along trench sidewall and bottom using high resolution transmission electron microscopy. The trench was formed by HBr plasma and additive gases in magnetically enhanced reactive ion etching system. Adding $0_2$ and other additive gases into HBr plasma makes it possible to eliminate sidewall undercut and lower surface roughness by forming the passivation layer of lateral etching, resulted in the well filled trench with oxide and polysilicon by subsequent deposition. The passivation layer of lateral etching was mainly composed of $SiO_xF_y$ $SiO_xBr_y$ confirmed by chemical analysis. It also affects the generation and distribution of lattice defects. Most of etch induced defects were found in the edge region of the trench bottom within the depth of 10$\AA$. They are generally decreased with the thickness of residue layer and almost disappeared below the uni¬formly thick residue layer. While the formation of crystalline defects in silicon substrate mainly depends on the incident angle and energy of etch species, the region of surface defects on the thickness of residue layer formed during trench etching.

• The Journal of Korean Academy of Prosthodontics
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• v.32 no.2
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• pp.327-353
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• 1994

This study was performed to evaluate the effects of number and alignment of implant fixture and various bar designs on the retention of denture and the stress distribution. Six kinds of photoelastic mandibular models and nine kinds of overdenture specimens were designed. A unilateral vertical load was gradually applied on the right first molar to calculate the maximal dislodgement load of each specimen. A unilateral vertical load of 17 Kgf was applied on the right first molar and a vertical load of 10 Kgf was applied on the interincisal edge region. The stress pattern which developed in each photoelastic model was analyzed by the reflection polariscope. The results obtained were as follows: 1. The maximal dislodgement load reversely increased with the distance from the loading point to the implant fixture, while it linearly increased with that from the most posterior implant fixture to the mesial clip. The maximal dislodgement load also increased with the use of a cantilever bar. 2. Under the posterior vertical load, the stress to the supporting tissue of the denture base increased with the distance from the loading point to the implant future. The stress concentration on the apical area of the implant future reversely increased with the distance from the loading point to the implant future. 3. In the overdentures supported by two implant fixtures under the posterior vertical load. the specimen implanted on lateral incisor areas with a cantilever bar exhibited more favorable stress distribution than that without a cantilever bar. The specimen implanted on the canine areas without a cantilever bar, however, exhibited more favorable stress distribution. 4. In the overdentures supported by three implant fixtures. the specimen implanted ell the midline and canine areas exhibited more favorable stress distribution than that implanted oil the midline and the first premolar areas. 5. In the overdentures supported by four implant fixtures. the specimen implanted with two adjacent implant fixtures exhibited more favorable stress distribution than that implanted at equal distance under the posterior vertical load. 6. Under the anterior vertical load, the overdentures supported by three implant fixtures exhibited stress concentration on the supporting structure of the middle implant future. In overdentures supported by two or four implant futures, no significant difference was noted in stress distribution between the types of bars. These results indicate that the greater the number of implant fixtures, the better the stress distribution is. A favorable stress distribution may be obtained in the overdentures supported by two or three implant fixtures, if the location and the design of the bar are appropriate.

• Journal of the Korean Chemical Society
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• v.42 no.6
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• pp.607-617
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• 1998

Au was dosed on $TiO_2(001)$ film grown epitaxially on Mo(100) surface in about 90 ${\AA}$ thickness. The growth mode of Au, thermal behavior and stability of the Au clusters, and the binding energy shift of Au 4f with the change in the amount of Au loading were studied by Auger Electron Spectroscopy (AES), Temperature Programmed Desorption (TPD) spectroscopy, Ion Scattering Spectroscopy (ISS), and X-ray Photoelectron Spectroscopy (XPS). Au grows three dimensionally on $TiO_2(001)$ film and the average size of Au clusters prepared at low temperature is smaller than those at higher temperature and the size increases with temperature irreversibly. Au clusters on $TiO_2(001)/Mo(100)$ start evaporation at 1000 K. TPD spectra of Au show very asymmetric peaks with the same leading edges irrespective of the amount of Au loading. The temperature at the peak maximum increases with the amount of Au. The desorption energy of Au obtained from the leading edge analysis of the TPD spectra is about 50 kcal/mol. The initial sticking coefficient of Au on $TiO_2(001)$ is constant in the temperature range of 200-600 K. The binding energy of Au 4f for the Au loaded on the film less than 2.0 MLE shifts to higher energy compared with the bulk Au. The shift is +0.3 eV at 0.1 MLE Au amount.

• Korean journal of communication and information
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• v.37
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• pp.43-72
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• 2007

This article is media education uses type of a middle high school students and research about effect that is taking media education. Measured media education uses motivation, studies own effect academic self-efficacy, media competence and school achievement for this research. As analysis result, priority media education uses motive was 'teaching convenience/help sought', 'Information/education method picking up sought', 'new teaching/communication thoroughgoing sought', 'ability elevation pursuit', 'self-regulating education sought', 'up-to-dateness sought', 'New knowledge/education sought' of order. By next time, only 'new knowl edge/education sought' motive caused positive effect in studies own effect among media education uses motive. Among media education uses motive, 'teaching convenience/help sought', 'Information/education method picking up sought', 'New study/communication thoroughgoing sought', 'self-regulating education sought', 'up-to-dateness sought' motive caused positive effect in media competence. Also, it caused positive effect among media education uses motive 'self-regulating education sought' and 'new knowledge/education sought' in students' school achievement. Finally, 'academic self-efficacy' is 'media competence' more in school achievement influence. Media education influenced new teaching method and ability elevation to some students. But, academic self-efficacy and school achievement did not cause big effect students. However, media education influenced in some students' media competence elevation.

• Journal of the Korea Society of Computer and Information
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• v.19 no.4
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• pp.1-8
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• 2014

As cores in multi-core processors are integrated in a single chip, power density increased considerably, resulting in high temperature. For this reason, many research groups have focused on the techniques to solve thermal problems. In general, the approaches using mechanical cooling system or DTM(Dynamic Thermal Management) have been used to reduce the temperature in the microprocessors. However, existing approaches cannot solve thermal problems due to high cost and performance degradation. However, floorplan scheme does not require extra cooling cost and performance degradation. In this paper, we propose the diverse floorplan schemes in order to alleviate the thermal problem caused by the hottest unit in multi-core processors. Simulation results show that the peak temperature can be reduced efficiently when the hottest unit is located near to L2 cache. Compared to baseline floorplan, the peak temperature of core-central and core-edge are decreased by $8.04^{\circ}C$, $8.05^{\circ}C$ on average, respectively.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.3
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• pp.32-39
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• 2009

In this paper, system optimization design technique of an impulse ground penetrating image radar (GPIR) in time domain is proposed to improve depth resolution of the system. For the purpose, time domain analysis method of key components such as impulse generator and UWB antenna is explained and by simulation, parameters of each component are determined. In particular, by standardizing the impulse signal, spectrum efficiency of a radiated impulse signal is improved and a U-shaped planar dipole antenna for a UWB antenna is developed. By equipping a parabolic metal reflector with the proposed antenna, external noise is prevented and the ability of radiating an input impulse into ground is improved. In addition, to remove ringing effect of the propose antenna which causes serious degradation of the system performance, resistors are loaded at the edge of the antenna and then Tx and Rx UWB antennas are optimized by simulation in time domain. For images of targets buried under the ground migration technique is applied and influence of tough ground surface on distortion of received impulse signals is reduced using technique of noise and signal distortion reduction in time domain and its time resolution is enhanced. To verify the design optimization procedure, a prototype of an GPIR and an artificial test field are made. Measurement results show that the resolution of the system designed is as good as that of a theoretical model.

• Journal of Korean Society of Forest Science
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• v.76 no.3
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• pp.206-217
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• 1987

To investigate and analyze the vegetational structure, thirty sites were sampled with clumped sampling method and seventeen belt transects were sampled to analyze the vegetational change during 8 years(from 1978 to 1986)at the Namsan Nature Park in Seoul. Robinia pseudoacacia community of actual vegetation covered 29.39%, Quercus mongolica community 21.25% and Pinus densiflora community 17.58% of the Mt. Namsan forest. The degree of human disturbance of vegetation of 8, 7 and 6 area covered 43.2%, 7.8% and 30.8% respectively. The Quercus mongolica community at the northern slope and R. pseudoacacia community at the edge zone will keep their present structure. And P. densiflora community at the eastern and southern slope shall be succeeded to deciduous trees such as Q. mongolica. As to changes of plant community structure during 8 years, density of understory species, species diversity and Raunkiaer's frequency class A and E showed an increase and vegetation structure was developed to unification.