• Journal of Preventive Veterinary Medicine
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• 제42권4호
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• pp.163-170
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• 2018

The cost-effectiveness of foot-and-mouth disease (FMD) control strategies was evaluated using a simulation model fitted to the 2010/11 FMD epidemic in the city of Andong, Republic of Korea. Seven FMD-control strategies were evaluated with respect to the direct cost of a FMD-control strategy, such as slaughtering, movement restriction, and vaccination. All the strategies included pre-emptive slaughtering, movement restriction, and vaccination, but the levels of each control option were different. The simulated median cost of the baseline FMD-control strategy (three kilometers of pre-emptive slaughtering area, 100 days of movement restriction and vaccination of all FMD-susceptible animals in the study area) was estimated to be USD 99.7 million. When a five kilometer vaccination area was applied (with the other control measures being the same as the baseline strategy), the simulated median cost was reduced to USD 81.1 million from USD 99.7. The simulated median costs were USD 107.6 million for a five kilometer radius slaughtering area and USD 168.8 million for 60 days of movement restriction. The FMD-control strategy cost decreased with increasing number of farms depopulated per day. The probability of passive surveillance being effective or the probability of the successful implementation of movement restrictions were increased. Cost-effectiveness analysis is a suitable tool for evaluating the financial consequences of FMD-control strategies by comparing the cost of control strategies for a specific area.

• International Journal of Control, Automation, and Systems
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• 제4권5호
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• pp.601-614
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• 2006

In this paper, a study on task assignment strategies for a complex real-time network system is presented. Firstly, two task assignment strategies are proposed to improve previous strategies. The proposed strategies assign tasks with meeting end-to-end real-time constraints, and also with optimizing system utilization through period modulation of the tasks. Consequently, the strategies aim at the optimizationto optimize of system performance with while still meeting real-time constraints. The proposed task assignment strategies are devised using the genetic algorithmswith heuristic real-time constraints in the generation of new populations. The strategies are differentiated by the optimization method of the two objectives-meeting end-to-end real-time constraints and optimizing system utilization: the first one has sequential genetic algorithm routines for the objectives, and the second one has one multiple objective genetic algorithm routine to find a Pareto solution. Secondly, the performances of the proposed strategies and a well-known existing task assignment strategy using the BnB(Branch and Bound) optimization are compared with one other through some simulation tests. Through the comparison of the simulation results, the most adequate task assignment strategies are proposed for some as system requirements-: the optimization of system utilization, the maximization of running tasktasks, and the minimization of the number of network node nodesnumber for a network system.

• 설비공학논문집
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• 제16권2호
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• pp.184-193
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• 2004

The purpose of this study is to evaluate the performance of various control strategies in commercial buildings which have been operated by the variable air volume (VAV) system. Two buildings in Seoul were chosen for the field study. The one (D building) combined by LonWorks has the constant airflow of supply fan and the proportional control of VAV units (damper type). The other (S building) combined by DDC has the PI control mode of the supply fan and the floating control of VAV units (venturi type). In estimating thermal comfort and energy performance through control modes of PI, PID, and CAV in the supply fan, we could identify several energy efficient operating control strategies for the VAV system.

• 아동학회지
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• 제35권6호
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• pp.135-152
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• 2014

The main purpose of this study was to examine the mediating effects of maternal control strategies on the relationship between preschoolers' temperament and compliance/noncompliance. A total of 125 mothers with preschoolers aged 3 and 4 years participated in this study. Preschoolers' temperament was reported by mothers. Maternal control strategies and preschoolers' compliance/noncompliance were observed in the laboratory using a clean-up task. There were four major findings. First, preschoolers with higher levels of activity exhibited less compliance, and preschoolers with higher levels of adaptability and activity displayed more noncompliance. Second, preschoolers whose mothers used fewer commands and more compliments displayed more compliance and less noncompliance. Third, mothers who rated their children higher in activity level used more commands with their children. Finally, the use of maternal commands mediated the association between preschoolers' activity level and compliance/noncompliance. When preschoolers' activity level and maternal control strategies were considered together to predict preschoolers' compliance/noncompliance, the relationship between activity level and compliance/noncompliance became nonsignificant. These findings suggest that the effects of temperament on compliance/noncompliance are indirect through maternal control strategies.

• Smart Structures and Systems
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• 제20권3호
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• pp.273-283
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• 2017

This paper presents and compares three feedback control strategies for active control of noise inside a 3-D vibro-acoustic cavity. These are a) control strategy based on direct output feedback (DOFB) b) control strategy based on linear quadratic regulator (LQR) to reduce structural vibrations and c) LQR control strategy with a weighting scheme based on structural-acoustic coupling coefficients. The first two strategies are indirect control strategies in which noise reduction is achieved through active vibration control (AVC), termed as AVC-DOFB and AVC-LQR respectively. The third direct strategy is based on active structural-acoustic control (ASAC). This strategy is an LQR based optimal control strategy in which the coupling between the various structural and the acoustic modes is used to design the controller. The strategy is termed as ASAC-LQR. A numerical model of a 3-D rectangular box cavity with a flexible plate (glued with piezoelectric patches) and with other five surfaces treated rigid is developed using finite element (FE) method. A single pair of collocated piezoelectric patches is used for sensing the vibrations and applying control forces on the structure. A comparison of frequency response function (FRF) of structural nodal acceleration, acoustic nodal pressure, and piezoelectric actuation voltage is carried out. It is found that the AVC-DOFB control strategy gives equal importance to all the modes. The AVC-LQR control strategy tries to consume the control effort to damp all the structural modes. It is seen that the ASAC-LQR control strategy utilizes the control effort more intelligently by adding higher damping to those structural modes that matter more for reducing the interior noise.

• Educational Technology International
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• 제6권2호
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• pp.101-111
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• 2005

This study was to examine effects of On-Line Community Assisted Small Group Peer Tutoring(OCSPT) on university students' learning strategies. To achieve the purpose, twenty-eight university students were randomly selected. Fourteen students participated in OCSPT and they were divided into small groups consisted of 2 to 5. Students in experimental group participated in OCSPT for total thirty-four hours during sixteen weeks. There is no treatment for the other fourteen students in control group. To measure students' learning strategies, Motivated Strategies for Learning Questionnaire (MSLQ) shorts has been used. The result revealed that students in experimental group showed higher possession than control group in resource-management strategy(p<.05). However, there were no significant difference between both groups in cognitive and motivative strategies.

• 한국직업건강간호학회지
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• 제8권1호
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• pp.56-67
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• 1999

This study was designed to identify the relationships of role-conflict and role-overload, coping strategies, and stress response of clerical workers. The subjects were 115 clerical workers from two company. The instruments were the role-conflict and role-overload scale developed by Lee(1989), coping scale developed by Latack(1986), and the stress response scale developed by Chang(1993). Analysis of data was done by descriptive statistics, Cronbach's $\alpha$, Pearson correlation coefficietnt, ANOVA. The results of this study were summarized as follows ; 1. The average score for the level of stress response was $83.6({\pm}9.1)$. The high risk stress group was 86.1% of the clerical workers, the latent stress group members was 13.9%, and healthy group was 0%. The overall stress level was very high. 2. Considering the coping strategies by sociodemographic factors, the use of control coping strategies showed significant differences by work-time. The use of symptom management coping strategies showed significant differences by sex, age, married status, year of career, pay, and type of work. The organizational coping strategies showed significant differences by year of education and type of work. 3. The clerical workers who had worked below 44 hours per week complained significantly lower stress response(F=4.942, p<.05). 4. Above 65% of all respondents answered that they needed all of organizational level coping strategies. 5. The role-confilct positively related to escape and organizational level coping strategies(r=.562, r=.495, p<.05). The role-overload didn't related to individual level coping strategies, but positively related to organizational level coping strategies(r=.320, p<.05). 6. The control coping strategies and the escape coping strategies positively related to symptom management, organizational level coping strategies(r=.409, r=.324, r=.316, r=.339, p<.05). 7. The relationship between role-related stress and stress response revealed positive correlation(r=.482, r=.431, p<.05), and the relationship between stress response and control, symptom management coping strategies revealed negative cor-relation(r=-.3204, r=-.3146, p<.05). In conclusion, this study revealed that relationship of role related stress, coping strategies, stress response was statistically significant. The result of this study support that coping strategies vary across situation of stress. Based on survey results, future studies should consider coping strategies in specific stress situation and concept of symptom management coping strategy. Also organizational or training interventions could be developed and initiate to help to increase the use of adaptive coping strategies in light of individual and situational differences.

• Journal of Power Electronics
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• 제11권2호
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• pp.120-131
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• 2011

This paper proposes two control strategies for the bidirectional Z-source inverters (BZSI) supplied by batteries for electric vehicle applications. The first control strategy utilizes the indirect field-oriented control (IFOC) method to control the induction motor speed. The proposed speed control strategy is able to control the motor speed from zero to the rated speed with the rated load torque in both motoring and regenerative braking modes. The IFOC is based on PWM voltage modulation with voltage decoupling compensation to insert the shoot-through state into the switching signals using the simple boost shoot-through control method. The parameters of the four PI controllers in the IFOC technique are designed based on the required dynamic specifications. The second control strategy uses a proportional plus resonance (PR) controller in the synchronous reference frame to control the AC current for connecting the BZSI to the grid during the battery charging/discharging mode. In both control strategies, a dual loop controller is proposed to control the capacitor voltage of the BZSI. This controller is designed based on a small signal model of the BZSI using a bode diagram. MATLAB simulations and experimental results verify the validity of the proposed control strategies during motoring, regenerative braking and grid connection operations.

• 한국세라믹학회지
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• 제42권8호
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• pp.542-547
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• 2005

Keys to the attainment of tailored properties in SiC ceramics are microstructure control and judicious selection of the sintering additives. In this study, three different strategies for controlling microstructure of liquid-phase-sintered SiC ceramics (LPS-SiC) have been suggested: control of the initial $\alpha-SiC$ content in the starting powder, a seeding technique, and a post-sintering heat treatment. The strategies suggested offer substantial flexibility for producing toughened SiC ceramics whereby grain size, grain size distribution, and aspect ratio can be effectively controlled. The present results suggest that the proposed strategies are suitable for the manufacture of toughened SiC ceramics with improved toughness.

• 농촌지도와개발
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• 제18권3호
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• pp.631-664
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• 2011

As agricultural companies encounter number of risks in their business, it is very important to control the risks for their stable management. So we examine the agricultural business risks and propose the risk management strategies for the agricultural companies. For these purpose, we analyze the agricultural business risks with which agricultural companies are confronted, and propose the agricultural companies' the risk management strategies. The results of this study are as follows : First, Changing the risk environment of agricultural business, we have to realize the importance of the agricultural risks and risk management in it. Second, When we choose the risk management strategies which are risk retention, risk avoidance, risk control, risk transfer and insurance, etc., we should always consider the frequency of loss and the severity of loss. Third, If we don't control the agricultural risks, we will be in a position to very difficult situation. So, Agricultural companies should lead to stronger effort to manage the risks for their stable business.