• Advances in materials Research
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• v.1 no.3
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• pp.205-219
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• 2012

Co-Re alloy development is prompted by the search for new materials for future gas turbines which can be used at temperatures considerably higher than the present day single crystal Ni-based superalloys. The Co-Re based alloys are designed to have very high melting range. Although Co-alloys are used in gas turbine applications today, the Co-Re system was never exploited for structural applications and basic knowledge on the system is lacking. The alloy development strategy therefore is based on studying alloying additions on simple model alloy compositions of ternary and quaternary base. Various strengthening possibilities have been explored and precipitation hardening through fine dispersion of MC type carbides was found to be a promising route. In the early stages of the development we are mainly dealing with polycrystalline alloys and therefore the grain boundary embrittlement needed to be addressed and boron addition was considered for improving the ductility. In this paper recent results on the effect of boron on the strength and ductility and the stability of the fine structure of the strengthening TaC precipitates are presented. In the beginning the alloy development strategy is briefly discussed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.9
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• pp.1671-1678
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• 2006

A real time system realization for binocular eyeball tracking mouse on the computer monitor being far from 30-40cm is presented in the paper. The processing for searching eyeball and tracking the cursor are that a facial image is acquired by the small CCD camera, convert it into binary image, search for the eye two using the five region mask method in the eye surroundings and the side four points diagonal positioning method is searched the each iris. The tracking cursor is matched by measuring the iris central moving position. The cursor controlling is achieved by comparing two related distances between the iris maximum moving and the cursor moving to calculate the moving distance from gazing position and screen. The experimental results show that the binocular eyeball mouse system is simple and fast to be real time.

• Journal of Korean society of Dental Hygiene
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• v.16 no.6
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• pp.909-918
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• 2016

Objectives: The purpose of the study was to investigate the correlation between self-esteem, self-efficacy, and awareness for disability in dental hygiene students. Methods: A self-reported questionnaire was completed by 521 dental hygiene students from 5 universities in Gwangju and Jeonnam frm June 13 to July 16, 2016. The questionnaire consisted of self-esteem by Rosenberg (10 items), self-efficacy by Schwarzer (7 items), and the negative awareness for disabled person by Siller (24 items) using Likert 5 point scale. Results: Those who did volunteer activity for disabled person showed high self-esteem and self-efficacy than those who did not. Students having disability-related training experience had high self-esteem (p<0.05). Higher the self-esteem was, higher the self-efficacy was (r=0.655). Higher the self-efficacy was, the lower the negative awareness was (r=-0.142). Higher self-esteem enhanced the positive awareness for the disabled person (r=-0.206)(p<0.01). Conclusions: The systematic curriculum development for the disabled person recognition improvement should be made in order to enhance self-esteem and self-efficacy of the dental hygiene students.

• Journal of the Optical Society of Korea
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• v.9 no.1
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• pp.26-31
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• 2005

We describe the design and the implementation of video-rate reflection confocal scanning microscopy (CSM) using an acousto-optical deflector (AOD) for the fast horizontal scan and a galvanometer mirror (GM) for the slow vertical scan. Design parameters of the optical system are determined for optimal resolution and contrast. The OSLO simulations show that the performances of CSM are not changed with deflection angle and the wavefront errors of the system are less than 0.012λ. To evaluate the performances of designed CSM, we do a series of tests, measuring lateral and axial resolution, real time image acquisition. Due to a higher axial resolution compared with conventional microscopy, CSM can detect the surface of sub-micrometer features. We detect 138㎚ line shape pattern with a video-rate (30 frm/sec). And 10㎚ axial resolution is archived. The lateral resolution of the topographic images will be further enhanced by differential confocal microscopy (DCM) method and computational algorithms.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.106-106
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• 2016

강의 산화 및 부식을 방지할 수 있는 표면처리 강판의 수요가 늘어나고 있다. 그 중 용융아연도금 강판은 뛰어난 경제성 및 도금성, 그리고 희생적 방식 특성으로 각광받고 있다. 자동차용 강판의 경우 도금 공정 이후의 표면 상태가 매우 중요하다. 도금 공정의 주된 표면 결함은 강판이 도금욕 내에서 이동 하면서 수반된 도금욕 내의 Zn-Fe-Al dross 입자에 기인한다. 도금공정 중 강판으로부터 용출된 Fe는 도금욕 내의 Zn 와 Al 과 반응하여 밀도가 높은 Bottom dross 나 밀도가 낮은 Top dross를 형성한다. 이에 본 연구에서는 강판으로부터 Fe의 용출속도에 미치는 도금욕 내 초기Fe 농도의 영향을 속도론적으로 평가하였다. 본 연구에서는 'Finger rotating method (FRM)' 방법론을 적용하였으며. 실험을 위해 수직 관상로 내부에 Zn-Al-Fe 시료를 장입한 알루미나 도가니를 위치시킨 후 온도를 $455^{\circ}C$로 설정하고, 지름 20mm의 Iron rod를 회전모터에 연결하여 Zn-Al-Fe 용탕에 침적한 후 회전시켰다. 실험 결과, 초기 Fe 함량과 용탕의 Fe포화 농도의 차이가 적을수록 Fe의 용출 속도는 감소하였으며 Dross 생성량 또한 적었다. 용탕 및 Iron rod 샘플 관찰 결과를 바탕으로 회전하는 Fe 시편으로부터 도금욕으로의 Fe 용출 메커니즘을 고찰하였다. 용출 모델을 토대로 모델링 한 결과, 용탕 내 Fe 농도 변화양상이 모델링 data와 실험 data가 동일한 양상을 보임을 확인 하였다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.1
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• pp.73-78
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• 2008

A polarimetric fiber-optic CT has been developed by using a sensing coil made of a length of sun fiber. A Faraday rotator mirror is attached to the end of the sensor coil to double the sensitivity and to suppress the residual linear birefringence effect. From the current measurements, the linear error no more than ${\pm}2[%]$ was obtained. The output of spun fiber sensor coil was compared with those of the twisted- and the flint glass fiber's, and it fumed out to almost 50 times, 2 times more sensitive, respectively.

• Animal Systematics, Evolution and Diversity
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• v.8 no.2
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• pp.211-222
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• 1992

The systematic study of freshwater rotifers was conducted with the materials collected from 205 sites in South Korea. As a result, 4 subspecies, 3 from of Family Brachionidae (Keratella, Notholca) was identified; of which, 1 from is new to the Korean fauna: Keratella quadrata f. testudo. Total 135 species, 15 subspecies, 9 varieties and 10 forms representing 14 families 40 genera are now recorded from Korea by adding the 1 from newly described in the present paper.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.2
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• pp.167-182
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• 2016

The purpose of this study is to investigate the effects of CEO technological capability on management performance and mediating role of firm's technological capability. The empirical data for this study are taken not from subjective studies released by companies but from the Korea Technology Guarantee Fund's(KTGF) technology assessment data. The result are as follows. First, CEO technological capability has a very significant and important influence on firm's technological capabilities and on technological performance(intellectual property rights(-), technology spillover effect(+)) and on management performance. Second, mediating role of firm's technological capability is revealed negatively only between CEO technological capability and intellectual property rights. Because of CEO technological capability has a significant influence on firm's technological capability and management performance, start-up based on expertise show a higher probability of success than the founder.

• Research in Community and Public Health Nursing
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• v.12 no.2
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• pp.375-389
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• 2001

The purpose of this study was to evaluate the effect of Self-foot Reflex Massage (SRM) programme on the physical condition and anxiety level of hypertension workers. The research was designed in the pre and post-test. Sample test was done in five workers with essential hypertension. They were divided in two groups:- Group A and Group B. The Self-foot Reflex Massage (SRM) was applied three times a week for Group A and five times a week for Group B. The SRM was given in 40 minutes each time for 4 weeks from the 1st of January to the 30th of April in 2001. In order to evaluate the effect on SRM. blood pressure, total cholesterol, triglyceride, HDL cholesterol and LDL cholesterol were measured as physical parameters and state trait anxiety inventory was used twice each time between before and after the exercise. The collected data was analysed by Mann-Whitney test with SPSS program. The results were as follows: 1. Average age for the subjects were 39.8 (ranged from thirty-two to fifty-three) and average period of hypertension history was 42 months (ranged from twenty to eighty-four). 2. There was no significant difference between two examined groups in blood pressure. But, there was a significant difference in SRM of pre and post-test for two groups. 3. There was no significant difference in blood cholesterol between two groups and between pre and post-test. 4. State trait anxiety showed significant difference between pre and post-test except the results between two groups. This result suggests that SRM is effective on the decrease of systolic and diastolic pressure and the relief of state trait anxiety except for the blood cholesterol. Therefore, blood cholesterol is needed further evaluation in large subjects and longer period. Further research is regarded as necessary to evaluate and to compare the precise effects of SRM on the foot reflex massage (FRM) in anxiety.

• Journal of the Korean Ceramic Society
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• v.40 no.8
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• pp.811-817
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• 2003

Recently, application fields of non-metallic minerals by utilizing their structure properties are broadening. Especially, layered minerals have not only excellent shielding or covering ability but also absorbing and storing characteristics of chemical elements between a layers. We considered about the above mentioned characteristics and added functional substances onto their surfaces for the preparation of new environmentally friendly functional materials. In this study, natural graphite and sericite were mainly used to produce for the new environmentally friendly functional building materials. Graphite surfaces were modified with a surfactant (Alkyl Benzyle Demethyle Ammonium Chloride) for anti-bacillus and penicillium. Surface modification mechanism are that primary adsorption by differential zeta potential between graphite and ABDM and secondary adsorption by interaction between surfactant chains take place. Surfactant layers were fully formed and it was expected up to 99.7% up the efficiency of anti-bacillus and penicillium. Also the prepared functional samples have a effect to improve a various efficiency such as electromagnetic wave shield(up to 95%), deodorization(up to 80%), heat storage(5%) etc.