• 한국과학교육학회지
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• 제22권1호
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• pp.122-131
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• 2002

본 연구는 수행 평가 방식의 중요성이 대두됨에 따라 실지로 수행형 평가 문항이 전통적인 선다형 평가문항에 비해 어떤 학생들에게 어떻게 유용한지를 분석한 연구이다. 이를 위하여 제 3차 수학 과학 성취도 국제비교 반복 연구에 사용된 선다형과 수행형 평가문항들을 내용영역별로 분석하여, 수행형의 평가문항과 선다형의 평가문항의 효율성을 비교 분석하였다. 자료분석 결과 수행형의 문항이 선다형의 문항에 비하여 학생들의 능력을 더 정확하게 추정함으로써 효율성이 높은 것으로 나타났다. 특히 환경이나 과학의 본성 영역에 비하여 지구과학, 생물, 물리와 화학 영역에서 수행형의 문항이 선다형의 문항에 비하여 학생들의 능력을 더 정확하게 추정하고 있음을 보여주었다. 또한 선다형의 문항에 비하여 적은 수의 문항으로 학생들의 능력을 추정함에도 불구하고 추정오차가 적어, 적은 수의 수행형 문항으로도 학생들의 능력을 정확하게 추정할 수 있음을 시사하고 있다.

• Tuberculosis and Respiratory Diseases
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• 제70권3호
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• pp.235-241
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• 2011

Background: The rising prevalence of asthma may be associated with the rising prevalence of obesity in developed nations. There are several studies showing that obesity increases the risk of asthma in adults. We investigated the association of each body composition scale and bronchial hyper-responsiveness. Methods: This study involved a retrospective review of the existing records for 279 subjects with respiratory symptoms, who underwent a pulmonary function test, a methacholine challenge test and a body composition test between May 2007 and June 2009. Results: Of the 279 subjects, 179 (64%) were female. There was a statistically significant difference in fat free mass and in fat free mass index between the normal bronchial responsiveness group and bronchial hyper-responsiveness group (p=0.036; p=0.000). There was no significant differences in body mass index, in fat mass and fat free mass index in the normal bronchial responsiveness group and bronchial hyper-responsiveness group in males. However in females, body mass index and fat free mass index were increased in the bronchial hyper-responsiveness group (p=0.044; p=0.000). Total body water (kg), fat free mass (kg) and soft lean mass (kg) were significantly different between the normal bronchial responsiveness group and bronchial hyper-responsiveness group (p=0.002; p=0.000; p=0.000). Conclusion: This study showed significant differences in fat free mass and in fat free mass index between the normal bronchial responsiveness group and the bronchial hyper-responsiveness group. In females, BMI, soft lean mass, and total body water showed significant differences between the normal bronchial responsiveness group and the bronchial hyper-responsiveness group. We concluded that bronchial hyper-responsiveness was associated with not only body mass index but also fat free mass index in female bronchial asthma.

• 한국컴퓨터정보학회논문지
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• 제15권2호
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• pp.55-64
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• 2010

본 논문은 수행시간이 빠르면서 효율성이 높은 새로운 Free Rectangle 특징을 사용한 Adaboost 알고리즘 기반 얼굴 검출 방법을 제안한다. 제안하는 Free Rectangle 특징은 동일한 면적의 분리가 가능한 두 개의 사각형으로 구성된 마스크로부터 정의된다. Haar-like 특징은 다양성을 높이기 위해 일반적으로 두 개 이상의 사각 영역으로 구성한 복잡한 마스크 구조를 갖는다. 하지만, 제안하는 특징 마스크는 두 사각형이 특징 윈도우 안에 놓이는 위치와 크기에 따라 효율성이 좋은 다양한 특징을 얻을 수 있다. 또한 제안하는 특징은 일반 Haar-like 특징과 달리 마스크 형태에 상관없이 두 사각 영역의 화소 합의 차만 계산함으로 수행 시간을 크게 줄일 수 있다. 실세계 영상에서 제안하는 Adaboost 알고리즘 기반 얼굴 검출 기법은 빠른 검출 속도와 높은 검출 결과를 보여 학습 데이터만을 바꿔 다른 물체 검출에도 쉽게 적용이 가능하다.

• 수산해양기술연구
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• 제32권4호
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• pp.411-420
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• 1996

The structure of the scale formed on the surface of Fe - Cr - X alloys exposed to 1143K high sulfidation($Ps_2$ = 1.11$\times$$10^-7$ atm, $Po_2$ = 3.11$\times$$10^-20$ atm) or sulfidation/oxidation(($Ps_2$= 1.06$\times$$10^-7$ atm, ($Po_2$ = 3.11$\times$$10^-18$ atm) environment has been observed and analysed using XRD, SEM/EDS. To investigate the possibility of protective film formed on the surface of the alloys, Aluminium, Nickel were selected as alloying elements. Thermodynamic phase stability diagram was used to predict the reaction path of scale formed on Fe - Cr - X alloys. Parabolic rate constant($K_p$) value with 6wt% Al in Fe - 25Cr alloy decreased significantly compared with the Fe - 25Cr alloy without 6wt% Al. Since thin layer of defect free sulfide film, (Al, Cr)Sx, was formed at the alloy/scale interface. Fe - rich sulfide scale at outer layer and Cr - rich sulfide scale containing porosity at inner layer of Fe - 25Cr alloy have been observed. The reaction path for these scales could be predicted by the thermodynamic stability diagram.

• Wind and Structures
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• 제18권6호
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• pp.599-618
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• 2014

In this study, a square rectangular tall building is considered to investigate the effects of turbulence integral length scale and turbulence intensity on the along-wind responses, across-wind responses and torsional responses of the tall building by Large Eddy Simulation (LES). A recently proposed inflow turbulence generator called the discretizing and synthesizing random flow generation (DSRFG) approach is applied to simulate turbulent flow fields. It has been proved that the approach is able to generate a fluctuating turbulent flow field satisfying any given spectrum, desired turbulence intensity and wind speed profiles. Five profiles of turbulence integral length scale and turbulence intensity are respectively generated for the inflow fields by the DSRFG approach for investigating the effects of turbulence integral length scale and turbulence intensity on the wind-induced responses of the tall building. The computational results indicate that turbulence integral length scale does not have significant effect on the along-wind (displacement, velocity and acceleration) responses, across-wind displacement and velocity responses, while the across-wind acceleration and torsional responses vary without a clear rule with the parameter. On the other hand, the along-wind, across-wind and torsional responses increase with the growth of turbulence intensity.

• Structural Engineering and Mechanics
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• 제17권3_4호
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• pp.557-572
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• 2004

Control systems are used to limit structural lateral deflections during large external loads such as winds and earthquakes. Most recently, the semi-active control approach has grown in popularity due to inexpensive control devices that consume little power. As a result, recently designed control systems have employed many semi-active control devices for the control of a structure. In the future, it is envisioned that structural control systems will be large-scale systems defined by high actuation and sensor densities. Decentralized control approaches have been used to control large-scale systems that are too complex for a traditional centralized approach, such as linear quadratic regulation (LQR). This paper describes the derivation of energy market-based control (EMBC), a decentralized approach that models the structural control system as a competitive marketplace. The interaction of free-market buyers and sellers result in an optimal allocation of limited control system resources such as control energy. The Kajima-Shizuoka Building and a 20-story benchmark structure are selected as illustrative examples to be used for comparison of the EMBC and centralized LQR approaches.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.11.1-11.1
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• 2011

We have developed a simple synthetic method for fabricating a wafer-scale colloidal crystal film of 2D crystals in a 1D stack based on a combination of two simple processes : the self-assembly of polystyrene (PS) nanospheres at the water-air interface and the layer-by-layer (LbL) scooping transfer technique. The main advantage of this approach is that it allows excellent control of the thickness (at a layer level) of the crystals and the formation of a vertical crack-free layer over a wafer-scale (4 inch). We investigate the optical and morphological properties of the PhC multilayers fabricated using various mono-sized colloidal crystals (250, 300, 350, 420, 580, 720, and 850 nm), and mixed binary colloidal crystals (300/350 and 250/350 nm).

• 한국유기농업학회지
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• 제23권4호
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• pp.703-713
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• 2015

A Linear Approximated Inverse Almost Ideal Demand System, suggested by Eales and Unnevehr, is estimated with monthly data set of Korean fruits consumption. LA/IAIDS consists of 6 demand equations which correspond to domestically produced Hanrabong, overwintering mandarin, strawberry, melon and tomato with imported orange. The results indicate that price and scale flexibilities are negative, as expected. And the significance is that a 10% increase in imported orange quantity is associated with 5.5% declines in the price of Korean Hanrabong while the price of other fruits is minimally affected. In addition, the estimate of scale flexibility of Hanrabong (-2.96) is much smaller than any other fruit. Hanrabong farmer might be in the face of deficit operation as a consequence of the substitution effect if orange would be imported in accordance with the Korea-U.S. free trade agreement.

• Journal of Plant Biotechnology
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• 제3권2호
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• pp.59-66
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• 2001

Photoautotrophic micropropagation systems do not include sugar in the culture media. This characteristic provides advantages to scale up the micropropagation systems comparing photomixotrophic micropropagation systems. A closed, large-scale photoautotrophic micro-propagation for transplant production system has been developed at Chiba University, Japan. New concepts and technologies were adapted to produce high quality transplants at minimum usage of resources, and as scheduled. Newly developed software for production management was used to enhance the efficiency of the transplant production system. Currently, virus-free transplants of sweetpotato (Ipomoea batatas (L.) Lam.) are vegetatively propagated and produced under sterilized conditions in this system. This system can also be used for production of transplants of any other species including horticultural and woody plants with a minimum of modification.

• 아동학회지
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• 제26권1호
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• pp.107-121
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• 2005

The preliminary Korean Paternal Involvement Scale of 84 items was constructed from items collected from free-response surveys with 106 middle school students and 33 fathers followed by consultation with experts. Those items were tested on a sample of 339 middle school students. The 82 items selected through item analysis were analyzed by factor analysis. Of these, 54 items were categorized into seven factors : leisure-life, proffering information, discipline, academic support, tradition-inheritance, material support, and everyday life. Leisure-life, proffering information, and academic support correlated with grade level of adolescents and fathers' education. The alpha coefficients of this scale ranged from .68 to .90.