• Journal of Periodontal and Implant Science
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• 제30권2호
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• pp.429-442
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• 2000

Based on current evidence in the literature, it is known that endotoxin is a weakly adherent surface phenomenon and that power-driven instruments can be used to accomplish definitive root detoxification and maximal wound healing without overinstrumentation of root and without extensive cementum removal. And one of the newly developed curette tips used with low power of piezoelectric ultrasonic scaler, is effective to remove calculus and not to remove the excessive cementum. The purpose of this study is therefore, to assess the influence of ultrasonic power and various working parameters on root substitute removal when instrumentation is performed with the curette tip on piezoelectric ultrasonic scaler. This study assessed defect depth, width and area resulting from instrumentation using a piezoelectric ultrasonic scaler with a curette type tip in vitro to acrylic resin block as a root substitute. The working parameters was standardized by the sledge device which controls lateral force(0.5 N, 1 N, 2 N) and instrumentation time(5 sec, 10 sec, 20 sec) and power setting was adjusted 0,2,4,8 in P mode. Power setting had the greatest influence on defect depth compared to lateral force and instrumentation time(standardized regression parameter estimates${\pm}$standard error, $0.37{\pm}0.02$, $0.19{\pm}0.02$, $0.07{\pm}0.02$). The effects on defect area also greatest for power setting($0.57{\pm}0.03$) compared to lateral force and instrumentation time($0.33{\pm}0.03$, $0.12{\pm}0.03$). The effect of the power setting on the defect width($0.15{\pm}0.01$) is not so great as defect depth or defect area compared to lateral force($0.12{\pm}0.01$) and effect of instrumentation time is minimal($0.02{\pm}0.01$). It could be concluded that the power setting has the greatest influence on the defect depth and area in curette type tip with low power of piezoelectric ultrasonic device. Many parameters can be adjusted in various situation in clinical use of piezoelectric ultrasonic scaler but the power setting is the first parameter to be adjusted.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1360-1363
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• 1997

Development and realizatioin of adaptive Active Noise Cntrol used for quieting transformer nosie are planed to provide workers with comfortable working environment and to attenuate the noise for residents in many noisy areas(power plant, power transformer, GIS transformer etc.).

• Child Health Nursing Research
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• 제13권3호
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• pp.329-337
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• 2007

Purpose: This study was done to describe the essential structure of the lived experience of working women raising children. Method: Data were collected from 10 employed women with children who were under 2 years of age. The analysis of the data was done using the phenomenological analytic method suggested by Colaizzi (1978). Results: In this study, 6 essential themes were extracted: 'knowing by intuition child-rearing is difficult', 'having guilt-conscious of not being able to perform duties as a mother', 'hard work of maintaining two jobs', 'Lost self', 'realizing that one has become amother', 'thirsting for a social support system'. Conclusion: With a rapidly increasing number of working women, the significance of this study in the field of nursing is in understanding the child-rearing experience of working women. The findings indicate the need for a systemic and emotional support system for working women raising children.

• Journal of Advanced Research in Ocean Engineering
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• 제1권2호
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• pp.94-105
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• 2015

In this study, a thruster allocation method of a deep-sea working vessel was proposed with the aims of producing the demanded generalized forces and moment for dynamic positioning while at the same time minimizing total power. For this, an optimization problem for thrust allocation was mathematically formulated with design variables, objective function, and constraints. The genetic algorithms (GA) was used to solve the formulated problem. The proposed method was applied to an example of finding optimal thrust allocation of the deep-sea working vessel having 5 thrusters. The result showed that the method could be used to determine better strategy for thruster allocation of the vessel as compared to existing study.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집(한일합동학술편); 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.753-758
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• 1987

The purpose of ocean thermal energy conversion (OTEC) plant control is to provide stable power efficiently by appropriately regulating the seawater flow rates and the working fluid flow rate under conditions of continually changing seawater temperatures. This paper describes digital control of working fluid flow rate based on an adaptive control theory for the "Imari 2" OTEC plant at Saga University. Provisions have been made for linkage between the software of the adaptive control theory and the hardware of the OTEC plant. In implementing the working fluid flow rate control, if persistency of excitation conditions are lost, the algorithm of identification often exhibits bursting phenomena. To avoid this difficulty, the stopping-and-starting rule for identification was derived and was used for the working fluid flow rate control. Satisfactory control performance was then obtained by using this digital control system.ol system.

• Current Optics and Photonics
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• 제1권3호
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• pp.233-238
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• 2017

In this paper we propose a freeform secondary lens for an LED fishing/working lamp (LFWL). This innovative LED lamp is used to replace the traditional HID fishing lamp, to satisfy the lighting demands of fishing and the on-board activities on fishing boats. To realize the freeform lens's geometry, Gaussian decomposition is involved in our optics-design process for approaching the targeted light intensity distribution curve (LIDC) of the LFWL lens. The simulated results show that the illumination on the deck, on the sea's surface, and underwater shows only small differences between LED fishing/working lamps and HID fishing lamps. Meanwhile, a lighting efficiency of 91% with just one third of the power consumption can be achieved, when the proposed LED fishing/working lamps are used instead of HID fishing lamps.

• 한국수소및신에너지학회논문집
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• 제27권5호
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• pp.597-603
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• 2016

In this paper a comparative thermodynamics analysis is carried out for organic Rankine cycle (ORC) and ammonia-water Rankine cycle (AWRC) utilizing low-grade heat sources. Effects of the working fluid, ammonia concentration, and turbine inlet pressure are systematically investigated on the system performance such as mass flow rate, pressure ratio, turbine-exit volume flow, and net power production as well as the thermal efficiency. Results show that ORC with a proper working fluid shows higher thermal efficiency than AWRC, however, AWRC shows lower mass flow rate of working fluid and lower pressure ratio of expander than ORC.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.60-70
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• 2009

This paper explores the ways in which collaborative working among multiple disciplines in building projects can be more effective and efficient. It focuses on the support that can be provided by the latest development in information and communication technologies. It also considers the growing interdependence between participants in the process and their changing roles as they harness the power of the new technologies in new collaborative arrangements. It is argued that collaborative working should be addressed holistically from the technological angle, the social angle, as well as the organisational angle, to ensure its successful implementation in the construction industry. A case study is given to illustrate the use of ICT in supporting value management studies. The key issues surrounding the emerging field of research - collaborative construction information management - and the potential benefits and challenges of its wide adoption are discussed at depth.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 E
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• pp.1678-1680
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• 1997

The pulsed power with the high voltage and current can be used to the fields of high speed pulses of energy in different forms such as electric current and voltage, electron beam, ion beam, x-rays, gamma rays, heat, magnetics fields, sound and shock waves. This paper is directed mainly at electrical engineers working on production and practical application of high speed pulsed power with high voltage and current.

• 간호행정학회지
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• 제7권3호
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• pp.511-529
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• 2001

Purpose : To analyze organization variables related to nursing between the doctors' strike and normal periods. Methods : The sample consisted of 1,220(600 for doctors' strike and 620 for normal periods) nurses working in 5 hospitals. Six instruments were used for data collection including Job Activity Scale(JAS; Laschinger, 1994), Organization Relationship Scale(ORS; Laschinger, 1994), Interpersonal Support Scale(developed by Firth et al., 1986 and revised by Ahn(2000), Self-efficacy Scale(Riggs & Knight, 1994),Job Satisfaction Scale(Slavitts et al., 1978), and Organizational Commitment Questionnaire(OCQ; Mowday et al., 1979). Results : There were significant differences among variables(i.e., formal power, interpersonal support, self-efficacy and organizational commitment)between doctors' strike and normal periods. The formal power was high during the normal period, however interpersonal support, self-efficacy and organizational commitment were high during the doctors' strike. Conclusion : Interpersonal support, self-efficacy and job satisfaction were change by working conditions, but organizational commitment was not changed by working conditions.