• Journal of Korean society of Dental Hygiene
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• v.16 no.1
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• pp.69-75
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• 2016

Objectives: The objective of this study was to examine the effect of mentoring function on job satisfaction, organization commitment, and turnover intention in the newly employed dental hygienists. Methods: Two hundred and fourteen dental hygienists in Daegu and Gyeongbuk completed a self-reported questionnaire from January to May 2013. The instrument for the questionnaire consisted of mentoring function, mentoring personality, job satisfaction, organizational commitment, and turnover intention. The data were analyzed by frequency analysis, ANOVA, correlation analysis, and multiple regression analysis. Results: The longer duration of the mentoring for the newly employees strengthened job satisfaction and organization commitment. The mentoring function had a positive effect on job satisfaction and organization commitment, and decreased turnover intention. The higher quality of personality overcome the turnover intention. Conclusions: The mentoring is very important to enhance the job satisfaction and organization commitment in the newly employees. Loner duration of work(${\beta}=.268$, p=0.008) explained higher job satisfaction. Higher quality of personality(${\beta}=0.279$, p<0.001) also had higher job satisfaction. The explanation power of the model was 36.5% and the revised model explanation was 35.6%. The effective mentoring is closely related to job satisfaction and organization commitment and it can reduce turnover intention.

• Journal of Korean Academy of Nursing
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• v.46 no.1
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• pp.19-28
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• 2016

Purpose: The purpose of this study was to test the mediating effect of psychological distress in the relationship between chemotherapy related cognitive impairment (CRCI) and quality of life (QOL) in people with cancer. Methods: A purposive sample of 130 patients undergoing chemotherapy was recruited for the cross-sectional survey design. Data were collected from November 2014 to June 2015. The instruments were K-MMSE (Korean Mini-Mental State Examination), Everyday Cognition (ECog), Hospital Anxiety Depression Scale (HADS), and Functional Assessment of Cancer Therapy-General (FACT-G). Data were analyzed using descriptive statistics, correlation, and multiple regression using Baron and Kenny steps for mediation. Results: The mean score for objective cognitive function was 27.95 and 69.32 for perceived cognitive decline. Overall quality of life was 91.74. The mean score was 17.52 for psychological distress. The prevalence was 56.2% for anxiety and 63.1% for depression, and 20.0% for CRCI. There were significant correlations among the variables, objective cognitive function and self-reported cognitive decline, psychological distress, and quality of life. Psychological distress was directly affected by CRCI. ($R^2=29%$). QOL was directly affected by CRCI. Psychological distress and CRCI effected QOL ($R^2=43%$). Psychological distress had a partial mediating effect (${\beta}=-.56$, p <.001) in the relationship between self-reported cognitive decline and quality of life (Sobel test: Z= -5.08, p <.001). Conclusion: Based on the findings of this study, nursing intervention programs focusing on managing cognitive decline, and decreasing psychological distress are highly recommended to improve quality of life in cancer patients.

• Water for future
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• v.28 no.1
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• pp.153-168
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• 1995

The purpose of this study is to develop an efficient model for the least cost design of multisite detention systems. The IDP (Incremental Dynamic Programming) model for optimal design is composed of two sub-models: hydrologic - hydraulic model and optimization model. The objective function of IDP is the sum of costs; acquisition cost of the land, construction cost of detention basin and pumping system. Model inputs include channel characteristics, hydrologic paramenters, design storm, and cost function. The model is applied to the Jung- Rang Cheon basin in Seoul, a watershed with detention basins in multiple branching channels. The application results show that the detention system can be designed reasonably for various conditions and the model can be applied to multi-site detention system design.

• Industrial Engineering and Management Systems
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• v.6 no.2
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• pp.136-145
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• 2007

The selection of suppliers and the determination of order quantities to be placed with those suppliers are important decisions in a supply chain. In this research, a non-linear mixed integer programming model is presented to select suppliers and determine the order quantities. The model considers the purchasing cost which takes into account quantity discount, the cost of transportation, the fixed cost for establishing suppliers, the cost for holding inventory, and the cost of receiving poor quality parts. The capacity constraints for suppliers, quality and lead-time requirements for the parts are also taken into account in the model. Since the purchasing cost, which is a decreasing step function of order quantities, introduces discontinuities to the non-linear objective function, it is not easy to employ traditional optimization methods. Thus, a heuristic algorithm, called particle swarm optimization (PSO), is used to find the (near) optimal solution. However, PSO usually generates initial solutions randomly. To improve the PSO solution quality, a heuristic procedure is proposed to find an initial solution based on the average unit cost including transportation, purchasing, inventory, and poor quality part cost. The results show that PSO with the proposed initial solution heuristic provides better solutions than those with PSO algorithm only.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.5
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• pp.361-368
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• 2015

This paper deals with a robust fine seek controller design problem with multiple constraints using a genetic algorithm. A robust $H\infty$ constraint is introduced to attenuate effectively velocity disturbance caused by the eccentric rotation of the disk. A weighting function is optimally selected based on the estimation of velocity disturbance and the estimated minimum velocity loop gain. A robust velocity loop constraint is considered to minimize the variances of the velocity loop gain and bandwidth against the uncertainties of fine actuator. Finally, a robust fine seek controller is obtained by solving a genetic algorithm with an LMI condition and an appropriate objective function. The proposed controller design method is applied to the fine seek control system of a DVD recording device and is evaluated through the experimental results.

• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.3
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• pp.138-146
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• 2021

The diagnosis and treatment plan for forming ideal occlusal plane in full mouth rehabilitation are difficult because each process is complicated and information exchange between dentist and technician is subjective. The OP finder^® system simplifies this process and helps to deliver more objective and accurate information. In this case, full mouth rehabilitation was performed using OP finder^® system for patients with old bad fixed prosthesis and severely worn mandibular teeth, and reported that the result of proper occlusal plane setting and masticatory function recovery was obtained.

• Structural Engineering and Mechanics
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• v.68 no.6
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• pp.735-745
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• 2018

The Big Bang-Big Crunch (BB-BC) algorithm is an effective global optimization technique of swarm intelligence with drawbacks of being easily trapped in local optimal results and of converging slowly. To overcome these shortages, an improved BB-BC algorithm (IBB-BC) is proposed in this paper with taking some measures, such as altering the reduced form of exploding radius and generating multiple mass centers. The accuracy and efficiency of IBB-BC is examined by different types of benchmark test functions. The IBB-BC is utilized for damage detection of a simply supported beam and the European Space Agency structure with an objective function established by structural frequency and modal data. Two damage scenarios are considered: damage only existed in stiffness and damage existed in both stiffness and mass. IBB-BC is also validated by an existing experimental study. Results demonstrated that IBB-BC is not trapped into local optimal results and is able to detect structural damages precisely even under measurement noise.

• Journal of Auto-vehicle Safety Association
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• v.11 no.3
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• pp.30-36
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• 2019

This paper suggests a car-following algorithm for urban environment, with multiple target candidates. Until now, advanced driver assistant systems (ADASs) and self-driving technologies have been researched to cope with diverse possible scenarios. Among them, car-following driving has been formed the groundwork of autonomous vehicle for its integrity and flexibility to other modes such as smart cruise system (SCC) and platooning. Although the field has a rich history, most researches has been focused on the shape of target trajectory, such as the order of interpolated polynomial, in simple single-lane situation. However, to introduce the car-following mode in urban environment, realistic situation should be reflected: multi-lane road, target's unstable driving tendency, obstacles. Therefore, the suggested car-following system includes both in-lane preceding vehicle and other factors such as side-lane targets. The algorithm is comprised of three parts: path candidate generation and optimal trajectory selection. In the first part, initial guesses of desired paths are calculated as polynomial function connecting host vehicle's state and vicinal vehicle's predicted future states. In the second part, final target trajectory is selected using quadratic cost function reflecting safeness, control input efficiency, and initial objective such as velocity. Finally, adjusted path and control input are calculated using model predictive control (MPC). The suggested algorithm's performance is verified using off-line simulation using Matlab; the results shows reasonable car-following motion planning.

• Nuclear Engineering and Technology
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• v.52 no.7
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• pp.1443-1451
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• 2020

The objective of this study is to design a robust power control system for a small pressurized water reactor (PWR) to achieve stable power operations under conditions of external disturbances and internal model uncertainties. For this purpose, the multiple-input multiple-output transfer function models of the reactor core at five power levels are derived from point reactor kinetics equations and the Mann's thermodynamic model. Using the transfer function models, five local reactor power controllers are designed using an H infinity (H_∞) mixed sensitivity method to minimize the core power disturbance under various uncertainties at the five power levels, respectively. Then a multimodel approach with triangular membership functions is employed to integrate the five local controllers into a multimodel robust control system that is applicable for the entire power range. The performance of the robust power system is assessed against 10% of full power (FP) step load increase transients with coolant inlet temperature disturbances at different power levels and large-scope, rapid ramp load change transient. The simulation results show that the robust control system could maintain satisfactory control performance and good robustness of the reactor under external disturbances and internal model uncertainties, demonstrating the effective of the robust power control design.

• Journal of Korean Society for Quality Management
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• v.18 no.2
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• pp.81-92
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• 1990

This paper considers a scheduling of a set of jobs on single and multiple processors, when all jobs have a common due date and earliness and lateness are penalized at different cost rates. The objective is to determine the optimal value of a common due date and an optimal scheduling to minimize a total penalty function. It is also shown that a schedule having minimum weighted completion time variances must be V-shaped. For identical processors, a polynomial scheduling algorithm with the secondary objectives of minimizing makespan and machine occupancy is developed and a numerical example is presented.