• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.5
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• pp.871-878
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• 2017

The quality control personnel of the construction work shall establish and execute the quality control plan or the quality test plan and check the qualification of the used materials according to the process, the management of the test and inspection equipment, the quality education, the own quality inspection and measures. Management and quality test of Korea and plays an important role in preventing accidents. However, related organizations did not explicitly disclose their roles in quality testing and quality control tasks while changing the names of quality control personnel to test personnel and quality managers when revising related laws and regulations and the application of labor costs. Therefore, a research of this is needed to improve conflicting situation. In this study, the ambiguous title relation to the quality control persons is improved to meet the requirements of the construction work based on related laws and regulations, and each role and title is classified as 'quality tester' and 'quality manager'. In other words, the person who carries out the quality test of the "Construction Quality Test Standard" specified in the Guideline for Quality Management of Construction Projects shall be the "Quality Tester" and the person who performs the quality control plan establishment and execution work specified in the Enforcement Rule of the Construction Technology Promotion Act shall be referred to as the 'Quality Manager'.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.5
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• pp.163-173
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• 2020

In this study, on-site corporate instructors participated as student-cum-workers in a degree-linked high skills Meister course to improve job competency and practical ability as proposed in the Work-Study Career Vision. Evaluation questions were then developed and their validity was verified by assessing satisfaction related to expected goals in enhancing advanced training guidance and competency as an evaluator. Satisfaction assessment was conducted based on training preparation, training implementation, training effectiveness and training administration. The Delphi Method was adopted and a total of 48 items were developed in 6 categories under 4 main areas. There were 7 evaluation items on the satisfaction of training course development under training preparation, 21 evaluation items related to the satisfaction of Off-JT and OJT courses under training implementation, 16 evaluation items related to the satisfaction of increased competency as an on-site corporate instructor and the satisfaction of enhanced practical skills and skills application at work under training effectiveness, as well as 6 evaluation items to assess satisfaction with administrative support under training administration. The final conformity assessment was conducted based on the stability, content validity ratio, consensus and convergence indicators of the developed items. Results of this study do not only apply to quality management of the high skills Meister course which is being promoted as a pilot project for work-study programs, but also serves as a rationale that may be considered as a basic research tool in the collection of various opinions to derive overall system improvement factors for the work-study high skills Meister course.

• Journal of the Korean Data and Information Science Society
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• v.24 no.1
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• pp.105-115
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• 2013

As far as the universities in south Korea are concerned, they have to meet the need of the situation as the number of the incoming students are decreasing because of the population-reducing in south Korea. The Ministry of Education Science and Technology is enforcing the restructuring of an universities by evaluating all the universities in Korea by using some indices (employment rate, supplement rate of students etc.). Most of the universities in Korea are widely permitting the changes of the major study as a method to improve the 'supplement rate of students' among some measures. These changes of major study (moving in and moving out) can give rise to difficulties in managing an university because there might be the departments with a small number of students as they moving out from low level departments to high level ones. Moreover, as raising the change rate of the major study, there is no loss from the university's point of view but a department could be in a difficult situation. The purpose of this study is to grasp the characteristics for changing major study by a general statistical analysis and graphs produced by a social network analysis with the D university's case. The results of this study are as follows; (a) category is from the engineering to humanity-society, (b) entrance level is from low to high, and (c) employment rate is from low to high as well.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.3
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• pp.301-307
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• 2010

Actuation using a shape memory alloy (SMA) is considered to be an important technology that will play a leading role in market for next-generation medical devices because an SMA actuator can accurately imitate skillful and delicate hand movements. However, SMA actuators have not been successfully used because of problems in control design caused by the nonlinear hysteresis effect of SMA, which leads to inaccuracies in control systems. In order to overcome the effect, the authors invented a SMA actuator, which could actively and rapidly cool down and heat up, by combining a SMA catheter and a TE module using the Peltier effect. In order to evaluate the TE characteristics of our TE module system, the changes in the temperature with 1) incremental increases in a continuous electric current and 2) the appearance of a discontinuous constant or reverse current are discussed in this paper.

• Polymer(Korea)
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• v.33 no.4
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• pp.319-325
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• 2009

The solution polymerization was conducted to synthesize pressure sensitive adhesive for polarizer film using acrylic monomers. 2-Ethylhexylacrylate, butylacrylate, acrylic acid were used as acrylic monomers. The ratio was 2-ethylliexylacrylate:butylacrylate:acrylic acid=25:50:3.6 by reflecting $-40^{\circ}C$ of glass transition temperature in the pressure sensitive adhesive. When 1 wt% of coupling agent was added to the polymerized pressure sensitive adhesive, the light transmissivity was significantly increased. This result is due to the enhancement of adhesive power against liquid crystal cell by Si-O bond of coupling agents. Cross-linking agent was added by 0.5, 1.0, and 1.5 wt% with respect to the synthesized polymer. Initial tackiness decreased, while cohesion increased with increasing crosslinking agent. In the analysis of contact angle, the increase of crosslinking agents yielded the enhancement of surface energy, resulting in the decrease of contact angle. From the measurement of heat resistance, the acrylic pressure sensitive adhesive showed excellent heat resistance regardless of change in temperature and contents in crosslinking agent. In the observation of a cutting plane, the increased crosslinking agent represented a smoother and cleaner section. Comprehensively, the optimum additive amount of crosslinking agent was determined to be 1.0 wt% to monomer.

• Journal of the Korean Society of Safety
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• v.22 no.6
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• pp.91-97
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• 2007

A survey of risk perception in Korea was conducted in 2001 with a special emphasis on industrial and technological risks. This article summarizes the characteristics of risk perception in consideration of socio-demographic background of respondents. The survey with sample size of 1,870 evaluates the perceived level of 25 risk items in the areas of transportation, chemicals, environment, industry, and nuclear power generation. Risks are categorized by using factor analysis to clarify attitudinal or behavioral properties of risk perception. Research findings show that the level of perceived risk does not correspond to the statistical level. Socio-demographic variables are significant predictors in explaining risk perception, or the discrepancies between "subjective" and "objective" risks. Effective risk communication can reduce the perceptional discrepancies, improve the awareness of technological risks, and ultimately facilitate the process of making and implementing policies for risk management and safety regulation. This article tries to provides policy guidelines for "Who is the target for risk communication" and "Which risk has the policy priority for safety improvement." Married females at the age of 30s and 40s with lower education and lower income in small cities are more vulnerable to risk misperception than other groups. More information and knowledge regarding unfamiliar, intangible, new technological risks should be delivered to the vulnerable groups for reducing perceptional bias. Society-wide safety can be improved by integrating policy, human, and social factors as well as techno-engineering advances.

• Journal of Navigation and Port Research
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• v.39 no.6
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• pp.457-463
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• 2015

A gas turbine engine plays an important role as a prime mover that is used in the marine transportation field as well as the space/aviation and power plant fields. However, it has a complicated structure and there is a time delay element in the combustion process. Therefore, an elaborate mathematical model needs to be developed to control a gas turbine engine. In this study, a modeling technique for a gas generator, a PLA actuator, and a metering valve, which are major components of a gas turbine engine, is explained. In addition, sub-models are obtained at several operating points in a steady state based on the trial running data of a gas turbine engine, and a method for controlling the engine speed is proposed by designing an NPID controller for each sub-model. The proposed NPID controller uses three kinds of gains that are implemented with a nonlinear function. The parameters of the NPID controller are tuned using real-coded genetic algorithms in terms of minimizing the objective function. The validity of the proposed method is examined by applying to a gas turbine engine and by conducting a simulation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.8
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• pp.1802-1809
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• 2009

Abstract The typical distribution systems have the power flow from distribution substations (sources) to customers (load) only as one direction. However, in the case where distributed generations (DG) such as PV system and wind power systems are connected to distribution systems, the DG output variations to distribution systems, so called reverse power flow, may cause the bi-directional power flow. So, the reverse power flow has severe impacts on typical power system, for example power quality problems, protection coordination problems, and so on. Especially, protection devices (sectionalizer) in primary feeder of distribution system interconnected with distributed generations may cause problems of malfunction, and then many customers could have problems like an interruption. So, this paper presents the bi-directional operation algorithm of protection devices to overcome the problems like mal-function. And, also this paper shows the effectiveness of proposed method by using both PSCAD/EMTDC software and test facility of protection devices to simulate the field distribution systems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.9-20
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• 2018

When a large-scale photovoltaic (PV) system is introduced into a distribution system, the customer's voltage may exceed the allowable limit ($220V{\pm}6%$) due to voltage variations and reverse power flow in the PV system. In order to solve this problem, we propose a method for adjusting the customer voltage using the existing step voltage regulator (SVR) installed in the primary feeder. However, due to the characteristics of a mechanically operating SVR, the customer voltage during the tap changing time of the SVR is likely to deviate from the allowable limit. In this paper, an energy storage system (ESS) with optimal operation strategies, and an appropriate capacity calculation algorithm are proposed, and the parallel driving scheme between the SVR and the ESS is also proposed to solve the customer voltage problem that may occur during the tap changing time of the SVR. The simulation results show that the allowable limit of the customer voltage is verified by the proposed methods during the tap changing time of the SVR when the large-scale PV system is connected to the distribution system.

• Journal of Convergence for Information Technology
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• v.11 no.9
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• pp.94-108
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• 2021

This study is to identify the internal and external factors of a company that can affect the rate of change in the inventory turnover ratio. In addition, by appropriately managing or responding to these factors, changes in the inventory turnover ratio do not occur abruptly, so that the company's business and financial performance can be improved. To confirm this, factors such as gross profit margin, cash flow volatility, advertising expenses, inflation, exchange rate rise, and leading economic index were selected, and these factors were predicted to affect the change rate of inventory turnover. Data of 85,878 companies were obtained from domestic securities listings, KOSDAQ listings, and externally audited companies, and multiple regression analysis was performed using the data. Gross profit margin and cash flow volatility have a significant positive (+) effect, advertising expenses have a negative (-) significant effect, and inflation and exchange rate rises have a negative (-) significant effect. As an influence, the leading economic index was tested to have a significant positive (+) effect. Through this, it is suggested that manufacturing companies can improve their business performance and achieve operational efficiency by well understanding and appropriately managing factors that can affect the change rate of inventory turnover.