• Journal of Korean Ophthalmic Optics Society
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• v.12 no.4
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• pp.107-110
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• 2007

Analysis of accommodation amplitude has been conducted for 137 adults, living in rural area, aged from their fifties to eighties. The methods included measurement of correction power for distance via auto-refractometer, measurement of near power based on trial frame and trial lens set, and calculation of effective accommodation amplitude using 1/2 and 2/3 of the maximum accommodation amplitude. The research results for participants aged in their fifties, sixties, seventies, and eighties showed 1.84~2.46D, 1.55~2.06D, 1.43~1.90D, and 1.22~1.62D respectively. It is relatively higher than the existing knowledge regarding accommodation amplitude associated with age.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2001.11a
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• pp.35-39
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• 2001

농산물은 기후와 시장동향에 따라 물량, 품질, 가격이 변동하고 산지에 따라 상품규격이나 품종이 다양하기 때문에 적기에 수출물량을 공급하고 지속적으로 확보하는 것이 어려운 문제로 대두되고 있다. 따라서 앞으로 농산물의 국제 경쟁력은 상품의 고품질화와 시장의 변화에 따른 상품의 안정적 공급에 달려 있다고 할 것이다. 연구결과에 의하면 작물이 안정적으로 생장하고 고품질의 수확물을 지속적으로 생산하기 위해서는 적정 일일적산광합성유효광양자속을 균일하게 공급할수 있어야 한다. (중략)

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2002.04a
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• pp.20-24
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• 2002

농산물은 기후와 시장동향에 따라 물량, 품질, 가격이 변동하고 산지에 따라 상품규격이나 품종이 다양하기 때문에 적기에 수출물량을 공급하고 지속적으로 확보하는 것이 어려운 문제로 대두되고 있다. 따라서 앞으로 농산물의 국제 경쟁력은 상품의 고품질화와 시장의 변화에 따른 상품의 안정적 공급에 달려 있다고 할 것이다. 연구결과에 의하면 작물이 안정적으로 생장하고 고품질의 수확물을 지속적으로 생산하기 위해서는 적정 일일적산 광합성유효광양자속을 균일하게 공급할수 있어야한다. (중략)

• Journal of the Korean GEO-environmental Society
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• v.13 no.4
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• pp.45-51
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• 2012

The shear strength of weathered granite soils under unsaturated condition was evaluated by $K_0$ consolidated triaxial tests. Various matric suctions in the unsaturated triaxial tests were applied using suction-controlled triaxial test apparatus for weathered granite soils obtained in Daegu. Soil water characteristic curve (SWCC) laboratory tests for drying and wetting procedure were performed and van Genuchten curves were fitted by experimental results. The contribution of matric suction in unsaturated soils is directly correlated to effective stress and evaluated from SWCCs. The effective stresses were estimated from these SWCCs and the relationship between effective stress and unsaturated shear strength was determined. In the effective stress description, the unsaturated shear strength with respect to various suctions indicates unique relationship and almost the same as that of the saturated envelope.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.385-393
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• 1994

고지대에서 개최되는 국제운동경기의 경우에 선수들의 고지대 적응이 경기 력에 큰 영향을 미치는 경우가 많다. 고지대에서의 경기는 선수들에게 현기 증을 일으키고 호흡, 순환계의 곤란을 유발시키며, 피로감을 증대시킨다. 국 내에서는 1983년 멕시코 세계 청소년 축구대회 당시 고지적응훈련의 일환으 로, 국내에서 마스크를 착용하고 연습한 사례가 있었다. 이 훈련방법은 정신 력 강화라는 심리적 측면에서 효과가 있을 수 있으나, 일반적으로 고지에서 2-3주간을 지속적으로 체류한 후에 순응이 일어난다는 사실과, 순응된 기능 이 저지대로 돌아올 경우 단시간내에 회복된다는 점을 감안할 때, 연습 시에 는 마스크를 착용하는 훈련방법이 동정맥산소교차의 감소로 저산소증을 유 발하는 고지상황에서의 호흡문제를 해결하는 데는 유효하지 않은 것으로 판 단되었다. 따라서 효과적이고 경제적인 고지적응 훈련은 인간기능에 관련된 변수들의 연관관계를 체계적으로 파악하고, 이 변수들을 효과적으로 조절하 여야만 가능할 것으로 평가되었다.

• Journal of Intelligence and Information Systems
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• v.17 no.1
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• pp.71-90
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• 2011

This study was designed to empirically analyze the effect of control activities(physical, managerial and technical securities) of information protection on organizational effectiveness and the mediating effects of information application. The result was summarized as follows. First, the effect of control activities(physical, technical and managerial securities) of information protection on organizational effectiveness showed that the physical, technical and managerial security factors have a significant positive effect on the organizational effectiveness(p < .01). Second, the effect of control activities(physical, technical and managerial securities) of information protection on information application showed that the technical and managerial security factors have a significant positive effect on the information application(p < .01). Third, the explanatory power of models, which additionally put the information protection control activities(physical, technical and managerial securities) and the interaction variables of information application to verify how the information protection control activities( physical, technical and managerial security controls) affecting the organizational effectiveness are mediated by the information application, was 50.6%~4.1% additional increase. And the interaction factor(${\beta}$ = .148, p < .01) of physical security and information application, and interaction factor(${\beta}$ = .196, p < .01) of physical security and information application among additionally-put interaction variables, were statistically significant(p < .01), indicating the information application has mediated the relationship between physical security and managerial security factors of control activities, and organizational effectiveness. As for results stated above, it was proven that physical, technical and managerial factors as internal control activities for information protection are main mechanisms affecting the organizational effectiveness very significantly by information application. In information protection control activities, the more all physical, technical and managerial security factors were efficiently well performed, the higher information application, and the more information application was efficiently controlled and mediated, which it was proven that all these three factors are variables for useful information application. It suggested that they have acted as promotion mechanisms showing a very significant result on the internal customer satisfaction of employees, the efficiency of information management and the reduction of risk in the organizational effectiveness for information protection by the mediating or difficulty of proved information application.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.2
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• pp.217-224
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• 2014

Purpose: This study was conducted to compare and analyze the accommodative system (accommodative response and accommodative lag) according to the material and font size of near visual media that we often encounter in daily life. Methods: Forty adult men and women aged 20 to 30 who not had specific ocular diseases and refractive surgery experience were examined to measure and compare the accommodative response according to the material of near visual media (print paper, newspaper, magazine, the I-Phone, LCD monitor) and font size (6, 8, 10, 12) by using both eyes open-view auto-refractometer. Results: The accommodative stimulus was $2.28{\pm}0.11D$ and the accommodative response was $1.66{\pm}0.30D$. The accommodative lag namely the difference between accommodative stimulus and accommodative response was $0.62{\pm}0.28D$. The accommodative response according to material of visual media using LCD monitor was $1.35{\pm}0.26D$ (p=0.00) and using the I-Phone was $1.55{\pm}0.25D$ (p=0.04). Both of them were statistically significant lower. The accommodative lag using LCD monitor was $0.93{\pm}0.24D$ (p=0.00) and using the I-Phone was $0.73{\pm}0.25D$ (p=0.04) and they were statistically significant higher. The accommodative response and accommodative lag according to font size were not statistically significant (p>0.05). Conclusions: During near working, the accommodative system was more affected by material than font size of visual media. Especially, visual media of non-luminous material (print paper, newspaper, magazine) are considered fewer burdens on eyes than luminous material (I-Phone, LCD monitor) in terms of accommodative system.

• Journal of Korean Ophthalmic Optics Society
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• v.11 no.4
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• pp.293-298
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• 2006

For this study, Clinical evaluation of the diverse Autorefractors was performed to examine validity and repeatability compared with subjective refraction. Measurements of refractive error were performed on 212 eyes of 106 subjects subjectivly noncycloplegic. Intersession repeatability of the Autorefractors were also assessed on all 106 subjects together with intersession repeatability on 7 to 14 days intervals. Spherical powers of subjective refraction and autorefractions by Autorefractors were analyzed by paired T-test.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.5
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• pp.363-370
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• 2013

Small scale hydropower is one of most attractive and cost-effective energy technologies for installation within sewage treatment plants. This study was conducted to evaluate the potential of a semi-kaplan micro-hydropower (MHP) system for application to sewage treatment plants with high flow fluctuations and a low head. The semi-kaplan MHP is equipped with an adjustable runner blade, and is without a guide vane, so as to reduce the incidence of mechanical problems. A MHP rating 13.4 kWp with a semi-kaplan turbine has been considered for Kiheung Respia sewage treatment plant, and this installation is estimated to generate 86.8 MWh of electricity annually, which is enough to supply electricity to over 25 households, and equivalent to an annual reduction of 49 ton $CO_2$. The semi-kaplan turbine showed a 90.2% energy conversion efficiency at the design flow rate of 0.35 $m^3/s$ and net head of 4.7 m, and was adaptable to a wide range of flow fluctuations. Through the MHP operation, approximately 2.1% of total electricity demand of Kiheung Respia sewage treatment plant will be achievable. Based on financial analysis, an exploiting MHP is considered economically acceptable with an internal rate of return of 6.1%, net present value of 15,539,000 Korean Won, benefit-cost ratio of 1.08, and payback year of 15.5, respectively, if initial investment cost is 200,000,000 Korean Won.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2339-2341
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• 2000

본 논문은 제어대상인 현수형 케이블의 수학적 모델을 작성하고 이것에 장력을 발생하는 교류서보 전동기의 수학적 모델을 구하였다. 제어 방법은 제어대상의 동적 모델이 비선형 시변계이기 때문에 강인성이 있는 퍼지제어를 적용하고 차대가 움직이기 시작할 때 발생하는 오버슈트을 억제하기 위해서 피드포워드제어를 채택한다. 케이블의 동적 모델에 기초하여 퍼지제어기와 피드포워드제어를 도입하여 시스템을 구성하고 시뮬레이션 실험에 의해 그 유효성을 평가하였다. 현재 로프제조 공정, 전차 트롤리선 가설공사는 장력의 제어가 필요하지만 거의 수동으로 행하고 있는 실정이고 제품의 균질성과 생산성 향상을 위하여 제조 공정의 자동화가 필요하다. 따라서 전차의 트롤리선 가설공사는 케이블을 탑재한 차대가 주행하면서 드럼에 감긴 케이블을 풀어주고 양단의 장력을 일정히 유지하도록 조절할 필요가 있다. 그러나 전기공사에서 시행하고 있는 송 배전 선로의 전력케이블 가선공사나 전차 트롤리선 가설공사는 수동으로 하고 있는 실정이고 이것의 자동화기계가 필요하다. 따라서 본 연구의 목적은 현수형 가선 케이블 가설장치의 자동화이다. 본 연구에서는 제어대상인 현수형 케이블의 수학적 모델을 작성하고 이것에 장력을 발생하는 교류서보 전동기의 수학적 모델을 구하였다. 제어 방법은 제어대상의 동적 모델이 비선형 시변계이기 때문에 강인성이 있는 퍼지제어를 적용하고 차대가 움직이기 시작할 때 발생하는 오버슈트를 억제하기 위해서 피드포워드제어를 채택한다. 케이블의 동적 모델에 기초하여 퍼지제어기와 피드포워드제어를 도입하여 시스템을 구성하고 시뮬레이션 실험에 의해 그 유효성을 평가하였다.