• Journal of Korean Society on Water Environment
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• v.28 no.1
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• pp.18-25
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• 2012

For effective watershed management, it is very important to select the tributaries through selection and concentration of targeted tributary catchments for improving water quality within the limited financial conditions. This study introduced the selection and diagnosis procedure of tributary catchments for improving water quality at Chungcheongnam-do based on water quality and flowrate monitoring, stream grouping method. The tributaries with high value of water quality and flowrate were selected for improving water quality according to stream grouping method. The diagnosis of selected tributaries for improving water quality was performed with analysis of the pollution load (generated, discharged, delivered) and point source discharged pollution load density. The plans for improving water quality of tributaries were suggested thorough various diagnosis of tributary catchments. For improving water quality of tributaries in Chungcheongnam-do, the tributary catchments in the Dangjin, Asan, Yesan, Cheonan, Hongseong area should be preferentially considered. The water quality improving plans for those tributary catchments, in accordance with the reduction of sources of pollution by population and livestock, should be established.

• Journal of Applied Reliability
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• v.17 no.3
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• pp.207-212
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• 2017

Purpose: This article provides an efficient cushion molding method for improving reliability of the rotation driving system. Method: Allowable stress level for cushion is calculated by using physical characteristics of the rotation driving system. In addition, various test units are manufactured and used to conduct the rebound resilience, the burst pressure and the alternating load test. Results: Actual allowable stress level and test results of the rebound resilience, the burst pressure and the alternating load test are provided. Conclusion: The cushion manufactured by the compression molding method gives more preferable characteristics for improving the reliability of the rotation driving system.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.8 no.3
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• pp.116-121
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• 2009

A novel method for improving the reliability of sensing data using multi-sensors in wireless sensor network systems is presented in this paper. This method is successfully applied a fog monitoring system in the mountain area.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.353-354
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• 2023

Improving productivity in industries is a very critical issue, and improving labor productivity is especially important in construction industry, which is a labor-intensive industry. However, researches on labor productivity in construction industry are insufficient, and most of previous studies have limitations in terms of specificity and logic. In this study, fuzzy DEMATEL method was used to structural analyze of influence factors for labor productivity in construction industry based on previous researches and expert survey. The result of this study contributes to deriving priorities for improving labor productivity.

• Journal of the Korea Safety Management & Science
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• v.9 no.3
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• pp.95-102
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• 2007

Nowadays, globally high-grade companies have done their best for increasing their competitive power through a many kinds of method in incisive competition for making certain of a pacesetting position. Among the rest, Six Sigma have been the best methodology of improving process and have proven to be effective by the result of improving process in many of manufacturing business, however, it has not obtained excellent results in the transaction business. In transaction business, a $30\sim50%$ costs in total costs is generated by slow-speed working and reworking. The slow processes decrease the quality and increase the cost, which decreases customer satisfaction, and finally the income is decreased. All of them are so called wastes in processes. For this, adopting of lean six sigma methodology in process management can eliminate the wastes and reduce the variation. This study focuses on distribution with the domains like capacity, layout, amount of location, assignment of product, operation procedure and operation rule in order to improve these domains, we make a further application of eight analysis ways based on DMAIC method for improving operation of processes of distribution center as the third profit source. The goal of this study is to trace an approach that can easily adopt of Lean Six Sigma in operational management of distribution center by a kind of data, analysis method and template.

• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.4
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• pp.273-278
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• 2019

This study proposes a method for improving the overmodulation performance of a three-phase inverter to obtain an enhanced output torque for the AC motors. In the inverter-fed AC motor drives, the output torque of the motor can be enhanced by utilizing the overmodulation region as well as the linear modulation regions of the inverter. The overmodulation method is used for this overmodulation operation of the inverter. However, the voltage gain, the ratio of the output voltage of the inverter to the reference voltage achieved by the conventional overmodulation methods becomes nonlinearly smaller than unity. Therefore, the effect of improving the output torque of the AC motors is insignificant even when the overmodulation region is utilized. In this study, we propose a method that improves the overmodulation performance of the inverter by compensating the limited amount of the reference voltage in the overmodulation operation to enhance the output torque of the AC motors. The effectiveness of the proposed method is verified through the simulations and experiments with an 800 W permanent magnet synchronous motor.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.34C no.12
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• pp.61-69
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• 1997

This paper proposes a new method for improving the performances of the neural network for optimization using a hyubrid of gradient descent method and dynamic tunneling system. The update rule of gradient descent method, which has the fast convergence characteristic, is applied for high-speed optimization. The update rule of dynamic tunneling system, which is the deterministic method with a tunneling phenomenon, is applied for global optimization. Having converged to the for escaping the local minima by applying the dynamic tunneling system. The proposed method has been applied to the travelling salesman problems and the optimal task partition problems to evaluate to that of hopfield model using the update rule of gradient descent method.

• Proceedings of the Korean Statistical Society Conference
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• 2005.11a
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• pp.141-146
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• 2005

Ensemble method has been known as one of the most powerful classification tools that can improve prediction accuracy. Ensemble method also has been understood as ‘perturb and combine’ strategy. Many studies have tried to develop ensemble methods by improving perturbation. In this paper, we propose two new ensemble methods that improve combining, based on the idea of pattern matching. In the experiment with simulation data and with real dataset, the proposed ensemble methods peformed better than bagging. The proposed ensemble methods give the most accurate prediction when the pruned tree was used as the base learner.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.308-309
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• 2018

This paper proposes new D/A(Digital to Analog) Design method for improving accuracy in high-performance test equipment. The proposed new D/A design can improve accuracy of the equipment even with low-resolution D/A converters. The validity of proposed D/A design is verified by analysis and experiment.

• Journal of the Korea Safety Management & Science
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• v.16 no.3
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• pp.351-362
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• 2014

A prerequisite for improving the quality of a product is to enhance the quality of its parts supplied from outsourced enterprises. An enterprise certified by ISO 9001 Quality Management System is expected to develop their effective quality assurance system and maintain it through continuous control and improvement, thereby ensuring the good quality of products that they produce. However, it is reported that small and medium-sized enterprises certified by ISO 9001 have difficulty establishing an effective quality assurance system. This study aims to propose a new method of improving a quality assurance system that can be more effective in small and medium-sized enterprises. This study collectively considered requirements specified in several international standards on quality system and the results of expert group brainstorming to identify evaluation areas and items for assessing a quality assurance system. Based on these evaluation areas and items, a set of checklists for diagnosing and improving a quality assurance system was developed. In order to demonstrate the usefulness of the proposed method, this study applied it to ten small and medium-sized enterprises and could identify four approaches for improving their current quality assurance system. The presented improvement method, which consists of establishment of quality goals and quality innovation plan, defective products corrective activities, 4M and design change process, improvement of customer quality information management, is expected to be utilized as a useful tool for the enhancement of the quality assurance system of small and medium-sized enterprises.