• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• 제12권11호
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• pp.982-993
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• 2000

This paper describes an optimal control scheduling of an encapsulated ice storage system with a chiller of nominal chiller 34RT(103,200kcal/hr) and an ice storage tank of 170RT-hrs(514,080 kcal). The optimization technique used in the study is dynamic programing. The objective function is summed cost during a day including charge and discharge periods. Control strategies being used commercially are chiller priority and storage priority control. In chiller priority control, the chiller is allowed to run at full capacity during the day, subject to limitations of the building load, and the ice is only melted when and if the load exceeds the chillers full capacity. In contrast to chiller priority control, the aim in storage priority control is to melt as much as ice as possible during the day time period. The system simulation calculates the operation costs for the three control strategies in the condition of the same cooling load and the same ice storage system. The simulation period is a day, assuming that initially the tank is stored fully and the cooling load is perfectly predicted for the scheduling. Also Final state of the tank is to be charged fully.

• Safety and Health at Work
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• 제2권4호
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• pp.375-379
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• 2011

Control Banding (CB) strategies to prevent work-related illness and injury for 2.5 billion workers without access to health and safety professionals has grown exponentially this last decade. CB originates from the pharmaceutical industry to control active pharmaceutical ingredients without a complete toxicological basis and therefore no occupational exposure limits. CB applications have broadened into chemicals in general - including new emerging risks like nanomaterials and recently into ergonomics and injury prevention. CB is an action-oriented qualitative risk assessment strategy offering solutions and control measures to users through "toolkits". Chemical CB toolkits are user-friendly approaches used to achieve workplace controls in the absence of firm toxicological and quantitative exposure information. The model (technical) validation of these toolkits is well described, however firm operational analyses (implementation aspects) are lacking. Consequentially, it is often not known if toolkit use leads to successful interventions at individual workplaces. This might lead to virtual safe workplaces without knowing if workers are truly protected. Upcoming international strategies from the World Health Organization Collaborating Centers request assistance in developing and evaluating action-oriented procedures for workplace risk assessment and control. It is expected that to fulfill this strategy's goals, CB approaches will continue its important growth in protecting workers.

• Safety and Health at Work
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• 제15권1호
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• pp.118-122
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• 2024

To understand biosafety's current situation in laboratory animal research and risk factors affecting occupational health. Compliance surveys were conducted by questionnaire via Questionnaire Star (an application app on the Internet) in Chinese. Thirty-nine anonymous questionnaires were collected. The surveyed institution has established 24 types of ABSL (Animal Biosafety Laboratory) and biosafety management organizations and systems equipped with safety equipment. Our study also suggests that the principal of the laboratory establishment fails to perform supervision and inspection responsibilities, the inappropriate design of the animal biosafety laboratory, non-standardized personnel training and health management, non-strict waste management, and insufficient emergency management. The administrative department and work units should address certain safety and occupational health risks in laboratory animal research. The author proposes control strategies based on organizational guarantee, personnel management, emergency management, etc., to help prevent risks and ensure occupational health. Due to regional limitations and small sample size, the results may not be generalisable to all parts of the world. However, some of the key common issuesmay also be present in other regions, sowe believe that this research still has some relevance.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.26-28
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• 1993

DD motor, with large rotor inertia & wide range of torque, is different from other servo motor in control & drive characteristic. In this paper, for the development of flexible DD robot, we introduced the h/w & s/w technics of DSP to construct the velocity, position & torque control strategies and integrated 2 axes special purpose DD servo dirver into one VME bus.

• Research in Community and Public Health Nursing
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• 제10권2호
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• pp.387-399
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• 1999

The purpose of this study is to identify the relationships of job stressor. coping strategies. and stress responses of manufactoring workers. Data were collected through self-reported questionnaires from 262 of the manufacturing workers in a local electronic company from July to August. 1999. For data analysis. Cronbach's a. Factor Analysis. Descriptive statistics. ANOVA. and Pearson's correlation coefficient with SPSS/PC+ 7.5 version program were used. The results were as follows: 1. Regard to the stress responses and coping strategies by sociodemographic variables. 'the overall stress responses' showed significant differences by sex. age. marrital state. The use of 'control coping strategy' showed significant differences by sex and the type of work. The use of 'avoid coping strategy' showed significant differences by sex. age. married state. year of career. and income. 2. The average scores of 'the job characteristics and participation in decision making factor'. 'the physical environmental factor'. and 'the role and leadership factor' were 2.66. 2.59. 2.59 in order. The average scores for 'the avoid coping strategy' and 'the control coping strategy' were 3.03. 2.97. The average scores for 'the overall. psychosoical. and physical stress responses' were 2.18. 2.18. 2.23. 3. The 'control coping strategy' was negatively related to 'the job characteristics and participation in decision making factor'. 'the role and leadership factor'. 'the psychosocial stress responses'. and 'the overall responses'. 'The control coping strategy' was positively related to all of 'the job stressors'. 'the physical stress responses', and' the overall stress responses'. 'The physical environment factor' was positively related to all of 'the stress reponses'. 'the role and leadership factor'. and 'the job characteristics and participation in decision making factor'. According to the results of this study, the suggestions were as follows: 1. The coping strategies of manufacturing workers in the specific job stress situation should be considered to future studies. 2. In order to applying the stress management program in the workplace. The organizational intervention focused on 'the job characteristics and participation in decision making' will be needed. 3. To support and use of 'control coping strategy' of the workers. the organizational efforts should be required.

• Korean Journal of Occupational Health Nursing
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• 제22권3호
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• pp.257-265
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• 2013

Purpose: This study aimed to investigate the job stress level of call center workers and figure out its relation with cognitive emotion regulation strategies as a cognitive coping strategy. Methods: Data collection was conducted on 985 call center workers, working for K companies in Korea. ANOVA, t-test, Scheffe's test and multiple regression have been conducted for the data analysis using SAS 9.0 software. Results: The total job stress score of subjects ranges $Q_{25{\sim}49}$ (the lower 50%) whereas the score of job demand and job control ranges $Q_{50{\sim}74}$ (the upper 50%), and its sectional job stress level is high. Since job stress is the major factor affecting cognitive emotion regulation strategies, it is shown that when the job stress score gets higher, the score of positive cognitive emotion regulation strategies gets decreased but the score of negative cognitive emotion regulation strategies, increased. Conclusion: Based on the results of this study, it is necessary to develop and apply an effective stress easing method for call center workers which reduces negative cognitive emotion regulation strategies and increases positive ones.

• Asian Pacific Journal of Cancer Prevention
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• 제16권4호
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• pp.1321-1325
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• 2015

Self-care to prevent cancer and self-management to cope with the disease are two discrete effective mechanisms for improving of control and management of neoplasia. Both them have certain strategies and practices. Often the two are used interchangeably despite their different approaches. Strategies of self-care usually refer to prevention at different levels include primary, secondary and tertiary. In contrast, strategies of self-management are related to management and alleviation of unpleasant cancer-related symptoms and treatment-related side effects for improving the quality of life of cancer survivors. Successful promoting of self-care and self-management strategies need people and survivor empowerment. Within this context, innovative approaches open a new window. In this paper after a brief review of related strategies and practices, we provide an explanation of how cancer portals may play an important role in the empowerment process and what are key potentials for implementing of self-care and self-management strategies for cancer.

• Nutrition Research and Practice
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• 제4권2호
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• pp.163-172
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• 2010

The purposes of this study were to assess hospital foodservice quality and to identify causes of quality problems and improvement strategies. Based on the review of literature, hospital foodservice quality was defined and the Hospital Foodservice Quality model was presented. The study was conducted in two steps. In Step 1, nutritional standards specified on diet manuals and nutrients of planned menus, served meals, and consumed meals for regular, diabetic, and low-sodium diets were assessed in three general hospitals. Quality problems were found in all three hospitals since patients consumed less than their nutritional requirements. Considering the effects of four gaps in the Hospital Foodservice Quality model, Gaps 3 and 4 were selected as critical control points (CCPs) for hospital foodservice quality management. In Step 2, the causes of the gaps and improvement strategies at CCPs were labeled as "quality hazards" and "corrective actions", respectively and were identified using a case study. At Gap 3, inaccurate forecasting and a lack of control during production were identified as quality hazards and corrective actions proposed were establishing an accurate forecasting system, improving standardized recipes, emphasizing the use of standardized recipes, and conducting employee training. At Gap 4, quality hazards were menus of low preferences, inconsistency of menu quality, a lack of menu variety, improper food temperatures, and patients' lack of understanding of their nutritional requirements. To reduce Gap 4, the dietary departments should conduct patient surveys on menu preferences on a regular basis, develop new menus, especially for therapeutic diets, maintain food temperatures during distribution, provide more choices, conduct meal rounds, and provide nutrition education and counseling. The Hospital Foodservice Quality Model was a useful tool for identifying causes of the foodservice quality problems and improvement strategies from a holistic point of view.

• Journal of Environmental Science International
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• 제25권2호
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• pp.191-216
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• 2016

Since prolonged exposure to elevated ozone ($O_3$) concentrations is known to be harmful to human health, appropriate control strategies for ozone are needed for the non-attainment area such as Seoul, Korea. The goal of this research is to assess factors linked with the 1-hour ozone exceedance through a decision tree model. Since ozone is a secondary pollutant, lag times between ozone and explanatory variables for ozone formation are taken into account in the model to improve the accuracy of the simulation. Results show that while ozone concentrations of the previous day and $NO_2$ concentrations in the morning are major drivers for ozone exceedances in the early afternoon, meteorology plays more important role for ozone exceedances in the late afternoon. Results also show that a selection of lag times between ozone and explanatory variables affect the accuracy of predicting 1-hour ozone exceedances. The result analyzed in this study can be used for developing control strategies of ozone in Seoul, Korea.

• Proceedings of the KIEE Conference
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.706-707
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• 2011

The insertion of the crowbar system in the doubly fed induction generator rotor circuit for a short period of time during grid disturbance enables a more efficient way of limiting transient rotor current and hence protecting the rotor side converter (RSC) and the DC - link capacitor. When crowbar is activated at fault occurrence and clearance time, RSC is blocked while DC -link capacitor and the grid side converter (GSC) can be controlled to provide reactive power support at the PCC and improve the voltage which helps to comply with grid codes. In this paper, control strategies for crowbar system to limit the rotor current during fault is presented with RSC and GSC controllers are modified to control PCC voltage during disturbance to enhance DFIG wind farm to comply with some strict grid codes. Model simulated on MATLAB/Simulink verify the study through simulation results presented.