• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.2
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• pp.124-137
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• 2018

Due to the decrease in coastal productivity and deterioration in the quality of ecosystem which result from the excessive overfishing of fisheries resources and the environmental pollution, fisheries resources in the Korean waters hit the dangerous level in respect of quantity and quality. In order to manage sustainable and effective fisheries resources, it is necessary to suggest the potential yield (PY) for clarifying available fisheries resources in the Korean waters. So far, however, there have been few studies on the estimation methods for PY in Korea. In addition, there have been no studies on the comparative analysis of the estimation methods and the substantial estimation methods for PY targeted for large marine ecosystem (LME) For the reasonable management of fisheries resources, it is necessary to conduct a comprehensive study on the estimation methods for the PY which combines population dynamics and ecosystem dynamics. To reflect the research need, this study conducts a comparative analysis of estimation methods for the PY in the Korean waters of the East Sea to understand the advantages and disadvantages of each method, and suggests the estimation method which considered both population dynamics and ecosystem dynamics to supplement shortcomings of each method. In this study, the maximum entropy (ME) model of the holistic production method (HPM) is considered to be the most reasonable estimation method due to the high reliability of the estimated parameters. The results of this study are expected to be used as significant basic data to provide indicators and reference points for sustainable and reasonable management of fisheries resources.

• Journal of Korean Society for Quality Management
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• v.47 no.2
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• pp.283-294
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• 2019

Purpose: Although the development of bulletproof helmets continues to be carried out, little has been improved in testing methods. Therefore, in this study, we studied the improvement of the test method of the domestic bulletproof helmet. Methods: The causes of head damage in the battlefield and the trends of bulletproof helmet development in developed countries were analyzed. In addition, improvements were derived by comparing the test methods of bulletproof helmet in Korea and the United States. Results: The results of the improvement by comparing the test methods of bulletproof helmet in Korea and the United States are as follows First, it is an addition to the scope of environmental treatment. Second, it is an addition to the level of protection. Third, the addition of the level of protection by impact. Conclusion: This study considered testing methods to prevent head injuries to shocks that cannot be identified by conventional methods. In addition, it considered testing methods for various threats by improving protection performance to advanced countries' levels.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.670-672
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• 2003

The market participants make plans of bidding and transaction strategies to maximize their own profits in competitive electricity market. Also, It is concerned with transmission congestion in power market. Two methods are generally used for congestion management;nodal pricing and uplift. The participants will have different strategies for their profits in the two methods. This paper analyzes their equilibrium strategies by using the supply function model and congestion methods.

• Journal of People, Plants, and Environment
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• v.24 no.5
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• pp.469-483
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• 2021

Background and objective: If the Nelumbo nucifera spreads in a wetland at a high density, it can have considerable positive and negative ecological effects on habitats. For this reason, it is necessary to precisely investigate the impacts of its rapid proliferation. This study was conducted to propose the distribution and management of N. nucifera, which can cause the degradation of wildlife habitats due to the rapid spread of internal and external environmental factors that may affect the Junam wetland ecosystem. Methods: For the investigation and analysis of physical and ecological characteristics, factors of the abiotic environment such as general weather conditions, topography and water depth structure, and soil and water quality analysis, and bioenvironment characteristics such as changes in the N. nucifera community distribution were evaluated. To assess whether the differences in the soil depth and physicochemical characteristics between the N. nucifera community and the aquatic plant community are statistically significant, a One-way ANOVA was executed. Results: N. nucifera was presumably introduced in approximately 2007 and observed at a prevalence of only 0.8% in 2009, but had expanded to 11.1% in 2014. After that, the area was increased to 19.3% in 2015 and 40.0% in 2017, about twice that of the previous survey year. The rapid diffusion of an N. nucifera colony can have adverse effects on wildlife habitats and biodiversity at Junam Wetland. To solve these problems, four management methods can be proposed; water level management, mowing management, installation of posts and removal of lotus roots. Control of the N. nucifera community using these methods was judged to be suitable for cutting and water level management when considering expansion rate, water level variation, and wildlife habitat impacts. Conclusion: As the biotic and abiotic environmental factors are different for each wetland, it is necessary to determine the timing and method of management through a detailed investigation.

• Environmental Engineering Research
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• v.18 no.2
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• pp.57-63
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• 2013

Arid areas have a significant problem with water supply due to climate change and high water demand. More than 3,000 years ago, Persians started constructing elaborate tunnel systems called Qanat for extracting groundwater for agriculture and domestic usages in arid and semi-arid areas and dry deserts. In this paper, it has been demonstrated that ancient methods of water management, such as the Qanat system, could provide a good example of human wisdom to battle with water scarcity in a sustainable manner. The purpose of this paper is twofold: Review of old wisdom of Qanat-to review the history of this ancient wisdom from the beginning until now and study the Qanat condition at the present time and to explore why (notwithstanding that there are significant advantages to the Qanat system), it will no longer be used; and suggestions for future water management-to suggest a number of new methods based on new materials and technology to refine and protect Qanats. With these new suggestions it could be possible to refine and reclaim this method of extracting water in arid areas. Also, a new multi-purpose water management model has been introduced based on rainwater infiltration management over the Qanat system as the model can be applied either in dry or wet cities to solve current urban water problems.

• 한국경영정보학회:학술대회논문집
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• 2007.06a
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• pp.646-651
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• 2007

Secure digital payment is critical in the successful shaping of global digital business. Digital payments are increasingly being used as a substitute to traditional payments, contributing markedly to the efficiency of the economy. The focus of every digital business transaction is to minimize risks arising from transactions. It is essential to ensure the security of digital payment whether used in internal networks or over wireless Internet. This paper analyses secure digital payment methods from the viewpoint of systemic security and transaction security. According to comparative analysis of digital payment models, this paper proposes a comparative analysis framework to investigate and evaluate secure digital payment. In conclusion, the comparative analysis framework, comparison of digital payment models and mobile payment models proposes a useful academic and practical foundation to enhance the understanding of secure digital payment methods. It also provides academic background and practical guidelines for the development of secure digital payment systems.

• Korean Management Science Review
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• v.21 no.2
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• pp.43-60
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• 2004

Every iteration of interior-point methods of large scale optimization requires computing at least one orthogonal projection. In the practice, symmetric variants of the Gaussian elimination such as Cholesky factorization are accepted as the most efficient and sufficiently stable method. In this paper several specific implementation issues of the symmetric factorization that can be applied for solving such equations are discussed. The code called McSML being the result of this work is shown to produce comparably sparse factors as another implementations in the $MATLAB^{***}$ environment. It has been used for computing projections in an efficient implementation of self-regular based interior-point methods, McIPM. Although primary aim of developing McSML was to embed it into an interior-point methods optimizer, the code may equally well be used to solve general large sparse systems arising in different applications.

• Journal of Korean Institute of Industrial Engineers
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• v.24 no.4
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• pp.529-537
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• 1998

Appropriate performance evaluation is a key successful factor for continuous improvement and systematic management support in the implementation of quality management. This research deals with the development of a computer support system for performance evaluation of quality management and its application to a real world problem. It, first, investigates existing performance evaluation methods and classifies them into three styles. A number of key factors for designing computer support systems are then elicited by analyzing the characteristics of the existing methods in terms of the requirements needed for a successful evaluation tool. The computer support system is designed by incorporating the key factors in the system design process and it is implemented as a network version. Finally, a case study is performed in order to verify the proposed support system. The pros and cons of the system are also discussed.

• Journal of odor and indoor environment
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• v.16 no.4
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• pp.297-307
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• 2017

As radon is a naturally occurring radioactive gas that can cause lung cancer and is classified as a Group 1 carcinogen, it is essential for the public to be aware of what radon is, and how to manage radon. Therefore, general information on radon, as well as its health risks, measurement methods, mitigation methods and suggestions for its management are addressed in this article. Over the last one to two decades, a number of wide-ranging studies on radon measurement and mitigation have been conducted in Korea, and the results of each study are comparable to the research achievements of other developed countries. For this reason, it is time to systematically establish a well-made Korean radon management organization.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1209-1215
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• 2009

Recently, Construction Projects are being much bigger and more complex. So the importance of Construction Planning and Management is increasing and increasing because of the Construction Projects is involved in a variety of construction-related subjects. Competitive of the Construction Industry decided Cost, Construction Duration and Productivity. But they were just focused on Cost Saving instead of Construction Duration and Productivity. However, they have to finish construction projects using minimum cost and duration with quality and function of required level for successful Construction projects. Thus, current high exchange rate and high period, it is clear to decrease construction cost and to do economic construction in huge Construction Projects and it means more advanced Construction Schedule Management needs for economic construction. But Construction Scheduling Planning, basic of Construction Schedule Management, adjusted contract period without Pre-Planning, just depending on experience and ability of Construction Engineer. Because of that, this study suggests new Duration Estimate Method using Stochastic Model in BIM Environment for advanced Construction Schedule Management. Existing Duration Estimate Methods are just modified wrong points of them or analyzed effective factors of construction schedule. However, New Duration Estimate Method is just consists of Stochastic Model and BIM Environment without existing Duration Estimate Methods. So, new method has creativity and specialty. After this research, it would be a great model in construction industry field.