• Korean Journal of Health Education and Promotion
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• v.17 no.2
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• pp.35-56
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• 2000

This study is research on physical health and mental health(physical and mental symptom at school) in perceived school environment among adolescents. The study subjects ere selected by senior high school students in seoul and random sampling. The 3,060 subjects were selected 18 schools. The duration for survey was for Nov. 25-Dec. 13, 1998. The reliability of Questionnaire was Cronbach's $\alpha=0.95$. This study used multiple regression through Factor Analysis in SPSS programs. The major findings of this study are as follows: (1) All of Multiple Regression Models were significant. (p<0.001). (2) Physical Mental health is related to gender, personal environment, and economic status. (3) Physical Health is related to perceived school environmental variable (therapeutic teacher-student relationships, classrom climate, and school life satisfaction) among adolescents. (4) Mental Health is related to perceived school environment variables(therapeutic teacher-student relationships, classroom climate, school life satisfaction, teachers' climate, and classmates' attitudes) among adolescents. This study could be used as the basis for the development of educational program, counseling, teacher in-service training, student teacher training and the establishment of educational and health policy.

• Proceedings of the Korean Biophysical Society Conference
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• 2001.06a
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• pp.64-64
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• 2001

Escherichia coli has developed soxRS regulon to defend against toxicity of superoxide radical. SoxR, superoxide sensor, is oxidized by superoxide-generating agents or nitric oxide and oxidized SoxR activates the transcription of soxS gene. In order to find out the trans-acting factors regulating SoxR activity in vivo, soxS：：lacZ single copy operon fusion construct was prepared and random Tn10 insertional mutatons were performed.(omitted)

• Journal of IKEEE
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• v.20 no.3
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• pp.291-294
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• 2016

A new optical one-time pattern password(OTPT) mutual authentication method is proposed, which presents a two-factor authentication by 2-step phase-shifting digital holography and performs a two-way authentication by a challenge-response handshake of the optical OTPT in both directions. Because a client and a server use OTPT once as a random number and encrypt it for mutual authentication, it protects against a replay or a man-in-the middle attack and results in higher security level.

• Advances in Computational Design
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• v.1 no.3
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• pp.275-296
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• 2016

This article presents an adaptive directional differential evolution (ADDE) algorithm and its application in solving discrete sizing truss optimization problems. The algorithm is featured by a new self-adaptation approach and a simple directional strategy. In the adaptation approach, the mutation operator is adjusted in accordance with the change of population diversity, which can well balance between global exploration and local exploitation as well as locate the promising solutions. The directional strategy is based on the order relation between two difference solutions chosen for mutation and can bias the search direction for increasing the possibility of finding improved solutions. In addition, a new scaling factor is introduced as a vector of uniform random variables to maintain the diversity without crossover operation. Numerical results show that the optimal solutions of ADDE are as good as or better than those from some modern metaheuristics in the literature, while ADDE often uses fewer structural analyses.

• Journal of the Korean housing association
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• v.2 no.2
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• pp.55-69
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• 1991

The purpose of this study were 1) to identify the pattern of general life style of the middle classs apartment residents. 2) to examine the types of the home furnishing attitudes of those. 3) to find out the relationships between life style and the home furnishing attitudes. The data were collected using self-administered questionnaire. The respondents were 227 homemakers of the middle class apartment residents, selected through stratified random sampling technique. Data were coded and analyzed using SPSS computer packages. The statistics used were frequency, percentage. Pearson's correlation coefficient, F-test, X2-test, factor and cluster analysis. 6 patterns of life style and 6 types of the home furnishing attitudes were identified. The relationships between the life style and the home furshing attitudes were interpreted by 25%.

• Proceedings of the Korea Concrete Institute Conference
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• 1991.10a
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• pp.87-92
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• 1991

It was achieved to formulate numerically the stress-strain relationship of concrete, which is a fundamemtal factor for the Elasto-Plastic analysis of concrete structures, for normal concrete by using random statistics. As a result of experiment, in the shape of stress-strain curves of normal concrete it has approach linear from first loading to peak point, and after that point deformation increased radically and specimens were brokendown abruptly. From the multiple linear regression, and obtained the exponential equaion for stress-strain relationship of concrete as follows: $\sigma$/$\sigma$max=e(1-$\varepsilon$/$\varepsilon$max)$\varepsilon$/$\varepsilon$max

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.11A
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• pp.904-908
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• 2009

The PZT(lead, zirconium, titanium) based ceramics which, are reported to be ferroelectric materials have their important applications in the areas of surface acoustic waves (SAW), filters, infrared detectors, actuators, ferroelectric random acess memory, speakers, electronic switches etc. Moreover, these PZT materials possess the large electromechanical coupling factor, large spontaneous polarization, low dielectric loss and low internal stress etc. Hence, keeping in view the unique properties of PZT piezoelectric ceramics we also tried to synthesize indigenously the small sized PZT ceramic powder in the laboratory by using the modified sol-gel approach. In this paper, Propyl alcohol based sol-gel method was used for preparation of PZT piezoelectric ceramic. The powder obtained by this sol-gel process was calcined and sintering to reach a pyrochlore-free crystal phase. The characterization of synthesized material was carried out by the XRD analysis and the surface morphology was determined by high resolution scanning electron microscopy.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.3_4
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• pp.384-394
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• 2003

The purpose of this research is to provide the apparel companies with a successful business strategy by analyzing the concept, function and current status of mileage programs; and examining how customer's attitude, recognition, experience, compensation method of the mileage program in apparel companies affect its brand loyalty. In this research simple random sampling was performed. The sample pool was based on 494 people which included college students and employed men and women in their twenties and thirties living in Seoul and in the metropolitan area. The data analysis was completed on the basis of SPSS package, using frequency, percentage, mean, standard deviation, factor analysis, variation, Scheffe test, regression, t-test, and X/sup2/. The following results were found in this research: It is effective to maintain brand loyalty through continuous relationship with consumers as fierce competition increases in apparel companies. A mileage program is a win/win strategy that allows clothing companies to increase its sales and brand loyalty while consumers feel greater satisfaction.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.3
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• pp.555-564
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• 2017

In this paper, a new technique for attitude and heading reference system (AHRS) using low-cost MEMS sensors of the gyroscope, accelerometer, and magnetometer is addressed particularly in vibration environments. The motion of MEMS sensors interact with the scale factor and cross-coupling errors to produce random errors by the harsh environment. A new adaptive attitude estimation algorithm based on the Kalman filter is developed to overcome these undesirable side effects by analyzing windowed measurement error covariance. The key idea is that performance degradation of accelerometers, for example, due to linear vibrations can be reduced by the proposed measurement error covariance analysis. The computed error covariance is utilized to the measurement covariance of Kalman filters adaptively. Finally, the proposed approach is verified by using numerical simulations and experiments in an acceleration phase and/or vibrating environments.

• Journal of Korean Institute of Industrial Engineers
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• v.33 no.3
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• pp.322-328
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• 2007

Highly standardized products are suitable for automated purchasing using electronic commerce technology, where the price becomes the most important factor. Suppliers can change the prices dynamically based on the inventory level and market situation in order to maximize the sales and profit. In the virtual marketplace where multiple customers purchase multiple standardized products from multiple suppliers repetitively, customers can purchase the required amount of each item as a dynamic bidding by allocating purchase orders to the suppliers based on the current price. Customers need a method to quickly determine the optimal allocation of orders to the suppliers using the dynamically changing data to minimize the total cost. We present a LP model which minimizes the sum of the total price plus transportation cost for this problem. Simulation results using random data show meaningful reduction of the total cost.