• 대한기계학회논문집
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• 제18권12호
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• pp.3127-3135
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• 1994

An approach to the simultaneous optimal design of structure and control system for large free-free flexible beam is presented. The flexible beam is modeled by the finite element method. And the reduced model of small degree of freedom is constructed by use of modal analysis. The tapered beam is considered so that the number of design variables is not dependent on the increasing number of finite elements. The width of several points of tapered beam and control gain are taken as design variables. The shape of beam and control gain are optimized simultaneously for the minimum weight of total structure including control system subject to the constraints of the magnitude of displacement of beam. It is shown that the simultaneous optimal design of structure and control systems is indeed useful.

• 가정과삶의질연구
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• 제29권3호
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• pp.59-69
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• 2011

The purpose of this study was to investigate the structural relationships among adolescents' internet addiction, self-esteem, self-control, and aggression. The participants were 300 students in their first year of middle school. The questionnaire consisted of measures of internet addiction, self-esteem, self-control, and aggression. The major findings were as follows: 1) self-control had a direct effect on aggression; 2) internet addiction had a direct effect on self-esteem and self-control; 3) self-esteem had a direct effect on self-control; 4) internet addiction had an indirect effect on aggression and self-control; and self-esteem had an indirect effect on aggression. This study implied that self-related variables could mediate the relationship between the possibility of internet addiction and adolescents' aggression. This study also suggested that research on various mediator variables could reduce adolescents' psychosocial problems.

• 생물환경조절학회지
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• 제10권1호
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• pp.42-49
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• 2001

온실의 환기제어시 외기의 온도와 풍속변화에 보다 유연하게 대처하면서 온도제어성능을 향상시키기 위하여 퍼지제어 알고리즘을 수립하고 제어실험을 실시하였다. 환기창을 열어 환기 시 온실의 실내온도 변화는 실내외온도차 및 외기 풍속의 세기와 방향에 영향을 받으므로 실내온도 기울기를 퍼지변수의 하나로 취급하여 퍼지변수의 수를 줄였다. 설정온도가 일정할 때 제어오차의 증분은 실내온도 증분과 같으므로, 전건부 퍼지변수는 제어오차(실내온도-설정온도)와 그 증분으로 결정하고, 후건부 퍼지변수는 환기창열음량 증분으로 결정하여 실내온도 하나만의 계측으로 제어출력이 가능한 퍼지제어 알고리즘을 구성하였다. 퍼지변수의 범위는 기초환기실험을 통하여 결정한 후 제어주기 3분을 갖는 실제실험 시 최적 값으로 보정하였다. 전건부 퍼지변수인 제어오차와 제어오차 증분의 최적범위는 각각 목표 제어오차의 3배와 1.5배, 후건부 퍼지변수인 환기창열음량 증분의 최적범위는 최대 열림량의 30%로 나타났다. 최적화한 19개의 퍼지규칙을 적용한 퍼지제어 알고리즘을 개발하고 상대적 성능평가를 위하여 최적 게인을 부여한 PID제어와 비교하였다. 퍼지제어와 PID제어의 실내온도 제어오차는 각각 1.3$^{\circ}C$, 2.2$^{\circ}C$ 미만으로 나타났다. 퍼지제어와 비교하였다. 퍼지제어와 PID제어의 실내온도 제어오차는 각각 1.3$^{\circ}C$, 2.2$^{\circ}C$ 미만으로 나타났다. 퍼지제어는 PID제어에 비해 환기창 적산열음량, 조작회수 및 반전조작회수가 0.4배, 05배 및 0.3배로 적게 나타나 외기풍속과 실내외온도차의 변동에 유연하게 대처하며 환기창의 점진적 여닫음 조작이 가능하고, 조작에너지도 1/2로 줄일 수 있는 것으로 나타났다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 춘계학술대회논문집
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• pp.176-179
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• 2003

The mean temperature prediction of strip is very important in hot strip finishing mill because of affecting on product quality and shape. Also, temperature can be used by basic information in other on-line control models with affecting control accuracy in factory. So, FE based on-line temperature model was developed for predicting strip mean temperature accurately in various process conditions and factory environments. There are many variables in affecting strip mean temperature in on-line states of factory. But some problems are occurred in considering all variables for making temperature model because of the bad efficiency of regression or fitting analysis. In this report, we have adopted dimensional analysis for solving these problems. We have many variables with dimensions affecting strip temperature but we are able to make non-dimensional variables less than dimensional variables from the combination of dimensional variables caused by PI-Theorem in fluid mechanics. The developed models are divided by two parts. The one is interstand temperature prediction model. The other is roll gap temperature model.

• 대한전기학회논문지
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• 제32권4호
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• pp.145-154
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• 1983

This paper presents a new method for optimal real and reactive power dispatch for the economic operation of a power system. Unlike the usual approach of minimizing the transmission loss, this method minimizes the total production cost not only for the real power optimization problem, but also for the reactive power optimization. The control variables are real power generation of units for real power optimization, and reactive power optimization. The constraints are the operating limits on these control variables and the limits on the bus voltages. Methematical models are developed to represent the sensitivity relationships between dependent and control variables for both real and reactive power optimization modules, and thus eliminate the use of B-coefficients. In order to handle many functional inequality constraints, a modified version of the gradient projection method is developed for optimization procedure, and has shown a remarkable advantage in computation efficiency.

• Journal of Information Technology Applications and Management
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• 제27권5호
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• pp.23-33
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• 2020

As the 4G and 5G Internet technologies become more common and developed, an environment for uploading and watching videos is created and spread, in addition to simply uploading posts. Watching and sharing daily life among media contents called Vlog, are very common more than ever. This means that individual users could access Vlog easily and the situation could be new trend. Additionally, academic research about Volg is increasing. We analyzed three independent variables affecting a perceived enjoyment we set up the dependent variable. Information search, self-expression, and social need are set as independent variables and social interaction is set as the control variable. Information search and self-expression are significant effect to perceived enjoyment except social need. In particular, social interaction as a control variable has effect to all relationships.

• Journal of Advanced Marine Engineering and Technology
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• 제31권4호
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• pp.462-467
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• 2007

The design and synthesis of a state feedback controller assumes the feedback of all state variables of the system. However, some state variables are not physical quantifies so that sensors may not be available, or may be too expensive to measure. Hence, a state observer can be an alternative to estimate unmeasurable state variables. This paper therefore presents a scheme for state observer-based stabilization control of inverted pendulum systems. The feedback gain matrices of both the state feedback controller and the state observer are tuned by real-coded genetic algorithms(RCGAs) such that the given performance indices are minimized. The proposed method is demonstrated through simulations.

• 전자공학회논문지C
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• 제34C권12호
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• pp.43-53
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• 1997

In this paper, the optimal synthesis algorithm of multiple-valued logic circuits using universal logic modules (ULM) U$_{f}$ based on 3-variable ternary reed-muller expansions is presented. We check the degree of each varable for the coefficients of reed-muller expansions and determine the order of optimal control input variables that minimize the number of ULM U$_{f}$ modules. The order of optimal control input variables is utilized the realization of multiple-valued logic circuits to be constructed by ULM U$_{f}$ modules based on reed-muller expansions using the circuit cost matrix. This algorithm is performed only unit time in order to search for the optimal control input variables. Also, this algorithm is able to be programmed by computer and the run time on programming is O(p$^{n}$ ).

• 한국학교보건학회지
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• 제34권1호
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• pp.33-41
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• 2021

Purpose: Exploring the variables that predict teachers' intent when referring students to mental health professionals is important. The Theory of Planned Behavio (TPB) is a theory of predicting people's intentions of performing a particular behavior; the intent to perform a certain behavior is determined by three factors. (1) attitudes toward the behavior, (2) subjective norms, and (3) perceived control. This study aimed to develop a TPB measurement to investigate what variables predict the intentions of teacher's referral behaviors. Methods: A qualitative study following standardized manuals and guidelines for developing a TPB measurement was used. As a qualitative research method, the Consensual Qualitative Research-Modified (CQR-M) was used. According to the findings from the qualitative study, the quantitative measurement to assess teachers' referral intention, attitude, subjective norm, and behavioral control was developed. Results: The reliability and validity of the newly developed measurement were tested and verified. Conclusion: The newly developed measurement would contribute to a future empirical study that will examine predictors of teachers' referral intention.

• 대한간호학회지
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• 제26권4호
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• pp.833-852
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• 1996

Regular long term dance movement could be one of ways to induce improvement of psychophysiological variables, resulting in improvement of quality of life. However, there have been few studies to evaluate the effect of dance movement training on both physiological and psychological variables in the elderly. This study was focused to determine the effect of Korean traditional dance movement training on psychophysiological variables-body weight, body fat, lean body mass, muscle strength, muscle endurance, flexibility, agility, resting heart rate and blood pressure, depression and life satisfaction-in Korean elderly women. Thirty four subjects, aged between 65 and 75years who have normal cognition, sensory function, cerebellum function, cardiovascular function, participated in this study. Seventeen experimental group subjects were selected from E-elderly university in Kyung Gi province, and Seventeen control group subjects were selected from N-welfare facility in Seoul City. Seventeen experimental group subjects participated for 12weeks dance movement program. Korean traditional dance movement program was developed on the basis of Korean traditional dance and music by the author. The program consisted of approximately 50minutes of dance, 3times a week for 12weeks. During 50minutes workout, there were 15minutes of warm-up dancing, 25minutes of conditioning dance and 10minutes of cool-down dancing. The intensity for the conditioning phase was at between 60% and 65% of age-adjusted maximum heart rates. The body weight, body fat, lean body mass, muscle strength(grip strength, leg strength), muscle endurance, flexibility, agility, resting heart rate and blood pressure, depression and life satis-faction were measured prior to and following the experimental treatment. The participants in dance movement were interviewed focusing on subjective feeling following 12 week's regular dance movement. Data were analyzed with mean, standard deviation, percentage of change, X²-test, t-test, and ANCOVA test using SPSS PC/sup +/ program. Subjective feeling was categorized into cognitopsy-chological and physiological responses. Results were obtained as follows : 1) The body weight (F=15.52, p=.000), body fat (F=18.33, p=.000) and lean body mass (F=7.28, p=.011) of the experimental group were significantly lower than those of the control group following the dance movement training. 2) The leg strength (F=30.96, p=.000), muscle endurance (F=9.06, p=.005), agility(F=44.92, 000), flexibility(F=6.84, p=.014) of the experimental group were significantly higher than those of the control group following the dance movement training. There was no significant difference of grip strength(F=.43, p=.515) between experimental and control groups. 3) The heart rate(F=26.96, p=.000), systolic (F=10.40, p=.000) and diastolic(F=3.99, p=.005) blood pressure at rest of the experimental group were significantly lower than those of the control group following the dance movement training. 4) No significant difference of score of depression (F=3.49, p=.071) was observed between experimental and control groups. 5) Score of life satisfaction of experimental group was remarkably higher than that of control group following 12weeks of dance movement training (p<0.05). 6) Thematic responses about the dance movement following the training were positive. "I feel good" was the most frequent among cognitopsychological responses and "I feel lightness of body" was the most frequent among physiological responses. The results suggest that Korean traditional dance movement training can improve psychophysiological variables of Korean elderly.