• Korean Journal of Environmental Agriculture
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• v.38 no.4
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• pp.307-313
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• 2019

BACKGROUND: An intensive farming system may be of the most important source for agricultural non-point source (NPS) pollution, which is a major concern for agricultural water management in South Korea. Various management practices have therefore been applied to reduce NPS loads from upland fields. This study presents performances of sediment trap for reducing NPS and soil loss from rainfall runoff in cropland. METHODS AND RESULTS: In 2018 and 2019, three sediment traps (L1.5 m × W1.0 m × D0.5 m = 0.75 ㎥) and their controls were established in the end of sloped (ca. 3%) upland field planted with maize crops. Over the seasons, runoff water was monitored, collected, and analyzed at every runoff. Soils deposited in sediment traps were collected and weighed at the season end. Sediment traps reduced runoff amount (p<0.05) and NPS concentrations, though the decreased NPS concentrations were not always statistically significant. In addition, sediment traps had a significant prevention effect on soil loss from rainfall runoff in a sloped cropland. CONCLUSION: The results suggest that the sediment trap could be a powerful and the best management practice to reduce NPS pollution and soil loss in a sloped upland field.

• Korean Journal of Construction Engineering and Management
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• v.18 no.2
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• pp.71-80
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• 2017

In recent years, the reduction of international award and project loss by Korean contractors have become a big issue not only in industry but also in academic fields. However, many researches have not focused on small and medium subcontractors but on the large contractors, even though the number of international project by small and medium companies is more than by large companies. Therefore, this study focuses on analyzing the predicted risk before bid and the actual risk after award in international subcontracting projects. In addition, it provides the difference between project performances according to the contract types and the project profitability. This study is expected to give more informed risk knowledge to small and medium subcontractors, which enables them to pay attention to managing risk for better project performances.

• Journal of Advanced Navigation Technology
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• v.20 no.2
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• pp.161-166
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• 2016

In high capacity and long haul optical communication systems, signal distortion is induced by chromatic dispersion and nonlinear effects of optical fibers. Dispersion management (DM) combining with mid-spans spectral inversion (MSSI) is one of the various techniques for overcoming this drawback. The most simple configuration of DM link is obtained by uniformly distributing the lengths of single mode fiber (SMF) and residual dispersion per span (RDPS) over whole fiber spans consisted of optical link. In this paper, the system performances in the uniformly distributed DM link combined with MSSI are assessed as a function of the number of fiber spans, because the system performances in this configuration are used as the significant performance criterion in other link configurations, such as the artificial distribution or the random distribution of SMF lengths and RDPS.

• Industrial Engineering and Management Systems
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• v.2 no.1
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• pp.9-27
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• 2003

In a wafer fabrication factory, the completion time of an order is affected by many factors related to the specifics of the order and the status of the system, so is difficult to predict precisely. The level of influence of each factor on the order completion time may also depend on the production system characteristics, such as the rules for releasing and dispatching. This paper presents a method to identify those factors that significantly impact upon the order completion time under various combinations of scheduling rules. Computer simulations and statistical analyses were used to develop effective due date assignment models for improving the due date related performances. The first step of this research was to select the releasing and dispatching rules from those that were cited so frequently in related wafer fabrication factory researches. Simulation and statistical analyses were combined to identify the critical factors for predicting order completion time under various combinations of scheduling rules. In each combination of scheduling rules, two efficient due date assignment models were established by using the regression method for accurately predicting the order due date. Two due date assignment models, called the significant factor prediction model (SFM) and the key factor prediction model (KFM), are proposed to empirically compare the due date assignment rules widely used in practice. The simulation results indicate that SFM and KFM are superior to the other due date assignment rules. The releasing rule, dispatching rule and due date assignment rule have significant impacts on the due date related performances, with larger improvements coming from due date assignment and dispatching rules than from releasing rules.

• Journal of the Korea Society for Simulation
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• v.18 no.1
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• pp.41-51
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• 2009

A discrete event simulation model is developed to evaluate the performances of three different revenue management methods for an air cargo network from Northeast China to North America and Europe. In the first method, a bid price model is applied only to the routes that pass through Incheon. In the second method, the bid price model is applied to all the routes. In third method, bid price and virtual nesting models are applied to the routes that pass through Incheon. The results show that the total revenue significantly increases with the employment of pricing and capacity control. The developed simulation model is a useful research tool to study marketing strategies for air cargo operations.

• Journal of Navigation and Port Research
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• v.35 no.1
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• pp.101-112
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• 2011

Nowadays, the third-party logistics is getting special attention as one of the most useful ways to perform the logistics management effectively. In this current trend, however, there are many firms which carry out the logistics activities by themselves and strengthen the competitiveness. In respect of contingency theory, the firms' logistics management types should depend on their logistics environment and characteristics, and then the logistics performances vary with this suitability. In this context, this study analyzed empirically the difference of the logistics performances due to the fitness between their logistics characteristics and the management types. According to the finding, the study showed that the third-party logistics is more suitable when the importance and weight of logistics operation and the weight of their export are greater respectively, and the self-logistics is more suitable when the logistics cost is higher. Futhermore, the study indicated that the firms whose relationship between the characteristics and the management types is fit in their logistics are better than the others in the outcome of logistics cost reduction and the effectiveness of logistics operation.

• Journal of Agricultural Extension & Community Development
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• v.20 no.1
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• pp.105-141
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• 2013

This study focuses on the vision-sharing practices, actual management capabilities and marketing competence for management which are supposed to be associated with the performance of village-based agricultural production sector. For this, vast literatures related to this issues were reviewed and analyzed. and which were used to establishment of research model. And then questionnaire were developed along the research model, survey were implemented using the questionnaire. In survey both of questionnaire and interview were used to obtain proper opinion. Total of 51 completed questionnaires were obtained and used to empirical analysis. The correlation method was used to investigate the relationships between factors affecting performance of agricultural production unit and performance. Major findings are as follows: (1) in overall, factors related to the vision-sharing or communication are not so important or even negative effects on the performance (2) in overall, factors of management competences are relatively associated with the performances positively (3) in overall, general management capabilities like planning or analyzing were positively related to the performance (4)significant factors which were related to the positive effects on the performances were alternatives considering risk of depreciation, securing stable customers, retention of professional personnels.

• Journal of Digital Convergence
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• v.17 no.3
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• pp.139-152
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• 2019

In the fourth industrial revolution and the era of convergence and integration, on the situation that the internal colleges are needed active change included in the improvement of educational quality, I tested it on the purpose of empirical analysis with SPSS v.18 how colleges' efforts on the first periodic Organization Evaluation And Accreditation System(OEAAS) affects on the Perceived Management Performances on the perspective of BSC. As the test result, the Degree of Awareness of Colleges' Efforts on the OEAAS affects on just Colleges' Learning and on Growth. The Degree Propriety of Preparation of the OEAAS affects on Customer Performance, on Internal Process Performance, and, on Finance Performance. And the Degree of Satisfaction of Internal Assessment affects on all of BSC 4 performances. The results of this research could be used on making the management idea of colleges' performance on the OEAAS. In the future, it would be needed advanced researches which are able to make relatedness to the expanse of management performance with the OEAAS.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.48-53
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• 2008

The performances of the building service equipment relay on the individual superintendent's share for the assessment of performance, fault detection, deterioration diagnosis of the building service equipment. A major use of building energy management system(BEMS) is for monitoring plant and building's energy consumption. National building management system (N-BMS) presented in this study links buildings into a network group in order to monitor and control the buildings. How to construct the N-BMS was considered to save energy resource and to conserve performance of building service equipment. The FEMIS, facility, energy/environmental management & information system, for building service offer management process integrated with BAS, FMS and EMS and so on.

• Journal of the Korea Society for Simulation
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• v.12 no.3
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• pp.69-81
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• 2003

To manage a cluster of distributed server systems, a number of management aspects should be considered in terms of configuration management, fault management, performance management, and user management. System performance monitoring and reporting take an important role for performance and fault management. In this paper, we present distributed system architecture modeling of a performance monitoring and reporting tool. Modeling architecture of four subsystems are introduced: node agent, data collection, performance management & report, and DB schema. The performance-related information collected from distributed servers are categorized into performance counters, event data for system status changes, service quality, and system configuration data. In order to analyze those performance information, we use a number of ways to evaluate data corelation. By using some results from a real site of a company and from simulation of artificial workload, we show the example of performance collection and analysis. Since our report tool detects system fault or node component failure and analyzes performances through resource usage and service quality, we are able to provide information for server load balancing, in short term view, and the cause of system faults and decision for system scale-out and scale-up, in long term view.