• 한국환경과학회지
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• 제26권1호
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• pp.119-131
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• 2017

This study evaluated the feasibility of recovering and recycling nitrogen (N) and phosphorus (P) from livestock excreta as struvite ($MgNH_4PO_4{\cdot}6H_2O$) in South Korea. Our experimental results showed that struvite precipitation was a very effective way to recover N and P from livestock excreta. Moreover, our study demonstrated that struvite precipitates from livestock excreta (SPL) contain higher concentrations of N, P, and magnesium (Mg) as compared to compost and liquid manure from livestock excreta. In addition, although SPL contain high concentrations of copper (Cu) and zinc (Zn), they meet the fertilizer criteria for concentrations of heavy metals. In South Korea, SPL cannot currently be used as a fertilizer due to legal constraints. Legal permission for SPL use would offer greater choice in livestock excreta management. In conclusion, recovery and recycling of N and P from livestock excreta as struvite can be an effective tool for managing nutrients in livestock excreta.

• KIEAE Journal
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• 제6권3호
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• pp.27-34
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• 2006

The recent emphasis on ecological urban development has led to the need to maintain a hydrologic cycle in urban areas. As such, this study proposes decentralized rainwater management, a concept of onsite rainwater management that involves the utilization, infiltration, detention, and retention of rainwater. The main objective of this research is to estimate the proportion of decentralized rainwater management that is needed. From the research that was conducted in this study, it was found that the total runoff quantity increases by 10-20% after district lands are developed, when the probable rate of precipitation every 10 years is within this range. Thus, the runoff rate can be reduced by 10~20% of the total runoff quantity through decentralization. On the other hand, in the scale of housing complex development, the total runoff quantity increases by as much as 10~40% due to the changes in the rate of the impervious surface area. If 10-40% of the total runoff quantity was processed through decentralized rainwater management, the rate of infiltration, detention, retention, and runoff in precipitation prior to development could be recovered.

• Journal of Korea Trade
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• 제24권5호
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• pp.35-54
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• 2020

Purpose - It seems common sense that corporate social responsibility (CSR) is a key driver of business sustainability. Nevertheless, there has been little research on the performance of socially responsible activities, including economic and environmentally responsibility activities, in internationally diversified firms. Design/methodology - The purpose of this study was to evaluate the effects of CSR activities on management performance. For this evaluation, an empirical analysis was conducted with total of 2,520 cases, selected from companies listed on the Korea Composite Stock Price Index market for six years from 2013 to 2018. As proxies for management performance, financial data such as a total asset net profit ratio and a total asset operating ratio were used. A multivariate regression analysis was conducted to test hypotheses. Findings - The results of this analysis indicated that firms in the CSR outstanding group were ranked significantly higher than other groups in management performance. In addition, CSR activities of internationally diversified firms positively influenced the total asset net profit ratio and total asset operating ratio. Originality/value - The results suggest that the CSR activities of these firms can play a significant role in enhancing management performance in the economic status of Korea, where the degree of export dependency is high.

• Journal of the korean society of oceanography
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• 제37권2호
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• pp.51-57
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• 2002

The ${\Delta}^5$ sterols were measured in be sediments of Jinhae Bay surrounded by industrial cities to assess the sewage-derived contamination. The total concentrations of total sterols ranged from 2.03 to 19.56 ${\mu}g/g$ dry wt. The principal sterol was cholesterol with a contribution of more than 50% to total sterols. Coprostanol, providing an indication of long-term sewage loads, was found in all sediment samples and the concentrations were 0.03-3.86 ${\mu}g/g$ dry wt, accounting for 1-26% to total sterols. The cluster analysis of sampling stations indicated that the sewage-derived contamination was localized in inner Masan Bay.

• 대한안전경영과학회지
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• 제12권4호
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• pp.153-160
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• 2010

In this paper, effects of information sharing in multi-level supply chain management have been studied through simulation. The simulation model consists of a manufacturing company as a center, three suppliers, two logistic centers, and three different retail supply lines of each logistics centers. The mathematical model and the simulation were developed when real-time information sharing occurs and does not occur in supply chain under the assumption that each company applies (s, S) inventory policies. In addition, this paper analyzed the effects of the change of variables related to total costs, which compose of total ordering cost, total transportation cost, total carrying cost and shortage cost that are caused by the change of demand of three different patterns with the way of information sharing.

• 한국물환경학회지
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• 제30권2호
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• pp.148-158
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• 2014

In order to assess the effect of TMDLs management and improve that in the future, it is necessary to analyze long-term changes in water quality during management period. Therefore, long term trend analysis of BOD was performed on thirty monitoring stations in Geum River TMDL unit watersheds. Nonparametric trend analysis method was used for analysis as the water quality data are generally not in normal distribution. The monthly median values of BOD during 2004~2010 were analyzed by Seasonal Mann-Kendall test and LOWESS(LOcally WEighted Scatter plot Smoother). And the effect of Total Maximum Daily Loads(TMDLs) management on water quality changes at each unit watershed was analyzed with the result of trend analysis. The Seasonal Mann-Kendall test results showed that BOD concentrations had the downward trend at 10 unit watersheds, upward trend at 4 unit watersheds and no significant trend at 16 unit watersheds. And the LOWESS analysis showed that BOD concentration began to decrease after mid-2009 at almost all of unit watersheds having no trend in implementation plan watershed. It was estimated that TMDLs improved water quality in Geum River water system and the improvement of water quality was made mainly in implementation plan unit watershed and tributaries.

• 동아시아경상학회지
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• 제7권4호
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• pp.15-26
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• 2019

Purpose - The purpose of this paper is to examine total logistics concept performed by 3^rd party logistics, managing with 4th party logistics to achieve more efficient and systematic dealing with sub-functions of physical distribution process. Research design and methodology - The research method to be adopted is first to review 3th party logistics providers that has attracted to various functions of 4PL, and then total logistics concept to be investigated which is related to 3 PL and 4 PL. Results - For the total logistics concept implemented by 3PL, management technique should be widen, then 3 PL's service activities and area should extend. Especially for the collaboration effects between the company and external organizations, it can be collaborated with some commitments in terms of their own independent activities, carrying on inherent functions by both 3PL and 4PL, pursuing total logistics concept. Conclusions - More areas of logistics service has been required by clients in the field, and service activities available is strongly related to roles of 3th party logistics providers as main player in logistics market. However, total logistics management is could be implemented by 3PL combining with various functions of logistics service offered by 4th logistics provider.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 1999년도 추계학술대회
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• pp.53-72
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• 1999

IPQC system was introduced for the flight safety at the age of scientific safety management in the 1980s. In spite of performing this system, aircraft accidents caused by human factors, which were above 70% among all flight accident factors, have not been reduced. Accordingly, throughout this paper I analyzed the aircraft accident factors by means of a literature study and a pilot survey. Then, based on the notion of TQC(Total Quality Control), I hierarchically classified Individual Quality into Capacity Management, Safety Management, and General Management and did the low-ranked management factors as well. AHP (Analytic Hierarchy Process), one of the scientific management methods, was used for estimating the relative importance of Individual Quality Control factors and the heavy aircraft accident causes over the last 20 years were analyzed according to the flight ranks. Based on the comparative analysis of results derived above, an IPQC model as flight ranks is established. In short, according to this newly suggested model we can obtain the maximum flight safety with the preventive actions against aircraft accidents caused by human factors and by improving the operation effect under the reasonable pilot management.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1414-1418
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• 2009

International construction projects typically manifest difficult, complex, and varied types of risk exposures; because of this, there is a need for accurate evaluation of risk-integrated performances during the timeframe of project execution. Given the financial crisis currently affecting the world economy recession, risk management has become a more crucial part for the success of international project management. However, the majority of risk management approaches, particularly for overseas projects, are focused primarily on simple forms of checklists, formalization of risk variables affecting project performance for a specific phase, or more complicated computational methods that restricting practical utilization in real-world projects; moreover, these methods lack the conceptual basis to broadly visualize the level of risk over all phases of a project. This study suggests an efficient, yet simple risk-integrated total index to successfully assess the risk levels of overseas construction projects. To this end, this paper first investigates the life cycles and key processes of decision-making for a given project and then derives formulas to represent the total risk index (TRI) along the key decision-making processes. In addition, the study examines the relationships between TRI and performance levels based on the analysis of 126 real-world project samples. Validations using the proposed TRI showed a high correlation to project performance, signifying the usefulness of the proposed approach for construction firms when investigating the level of risks and key areas for management focus.

• 한국경영과학회지
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• 제15권1호
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• pp.63-72
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• 1990

This problem in this paper concerns the determination of safety stock for multi-echelon invenetory system. In this model the criterion is to minimize system safety stock subject to a service level constraint and expected annual total cost. Then, safety stock is determined by minimizing expected annual total cost and satisfying given service level. This expected annual total cost is obtained by expected total inventory holding cost plus the expected total stockout cost. Numerical example is given in a three-echelon inventory system. The results obtained by the use of the Hill Algorithm.