• Journal of the Society of Naval Architects of Korea
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• v.41 no.1
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• pp.23-30
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• 2004

In the Lagrangian vortex particle method based on the vorticity-velocity formulation for solving the incompressible Navier-Stokes equations, a numerical scheme for calculating pressure fields is presented. Implementation of the numerical method is directly connected with the well-established surface panel methods, just by dealing with the dynamic coupling among vorticity field. Assuming the vorticity and the velocity fields are to be calculated in time domain analysis, the pressure calculation for a complete set of solution at present time step is performed in a similar way to the one used in the Eulerian description. For a validation of the present method, we illustrate the early development of the viscous flow about an impulsive started circular cylinder for Reynolds number 550. The comparative study with the Eulerian finite Volume method provides an extensive understanding and application of the mesh-free Lagrangian vortex methods for numerical simulation of viscous flows around arbitrary bodies of general shape.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.2
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• pp.63-71
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• 2010

The existing reliability evaluation models which have already developed by the corporations are so various because of using Maximum Likelihood Method. The existing models are very complicated owing to using system designing methods. Therefore, it is very difficult to utilize the existing models in business fields of many corporations. The purposes of this paper are as follows: The first purpose is to study the simple estimated Parameter to be easily utilized in the business fields of the corporations. The second purpose is to testify the simplification of the developed Parameter of estimated method by comparing the developed reliability evaluation model with the existing reliability evaluation models which are used in the business fields of the corporations.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.287-289
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• 1994

This paper deals with the planar-type electric field sensor which can measure the time-varying electric fields. The theoretical principle and design rule of the sensor are introduced, and also the calibration and application investigations are carried out. From the calibration experiments, the frequency bandwidth of the measurement system ranges from 160 [Hz] to 25 [MHz]. At a high voltage laboratory, the electric fields caused by the impulse voltage and oscillating transient voltage are measured by the proposed sensor. Obtained results are well agreement with the applied voltage waveforms.

• Journal of Science Education
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• v.46 no.2
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• pp.212-221
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• 2022

In this study, we propose an analytical model to elucidate the formation of electric fields between two parallel conducting plates. Using nine Gaussian surfaces, we investigated the charge redistributions and electric fields formed by parallel conducting plates when two charged plates get close together. The electric charges are redistributed via a new electrostatic equilibrium to create the electric field of each plates. As a result, the electric field start from + electrode plate to - electrode plate via inducing a new electrostatic equilibrium, implying that the application of Gaussian surfaces to only one of the electrodes of parallel-plate capacitors is deserved. The results will help undergraduate students understand the charge redistribution and the electric field formation in parallel-plate capacitors in a reasonable manner.

• Asia Marketing Journal
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• v.11 no.4
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• pp.121-128
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• 2010

This article challenges necessity of interdisciplinary studies between anthropology and marketing for more effective applications of ethnography in marketing fields. Anthropologist, Yong Sook Lee recently submitted an article about "application of ethnography in marketing fields" to open plaza at Korean Journal of Marketing. While she provides anthropologist' perspectives about applications of ethnography in marketing fields, this article attempts to enhance the marketers' understanding about ethnography by providing marketers's perspectives about the same issues.

• The Korean Journal of Zoology
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• v.24 no.3
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• pp.151-161
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• 1981

The field studies on the seasonal population prevalences of the vector mosquito larvae and other aquatic invertebrates were weekly carried out in the rice fields located in front of a village of Kwangtan-samri, Byeogje-myeon, Goyang-gun, Gyeonggido throughout mosquito breeding season (June-September) in 1980, and the results are as follows. The population of C. tritaeniorhynchus larvae increased soon after heavy rainfall, and decreased to some extent during the period of the insecticide application. The seasonal prevalence of A. sinensis was rather stable, not being affected by insecticide pressure at all. The population densities of other aquatic invertebrates in rice fields were seriously suppressed by the pesticide application, and their recovery was not as same as the previous level or not at all: (1) The populations of Odonata and Ephemeroptera nymphs were drastically decreased by the first application of insecticides and never recovered through out season. (2) Coleoptera seemed very susceptible to the insecticide application, as densities were markedly decreased whenever the insecticides were applied. (3) The high density of Hemiptera shown in early June were decreased sharply after the first application of pesticides, and thereasfter, some degree of recovery was shown, but suppressed by successive each application of pesticides. (4) A native species of planaria was exceptionally not influenced by the insecticide pressure, and two peaks of the density were appeared during the heavy rainfall.

• Korean Journal of Environmental Agriculture
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• v.33 no.2
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• pp.144-147
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• 2014

BACKGROUND: It is essential to prioritize the exact and clear understanding of agricultural nonpoint source pollution (NPS) controls. The realistic policies and systems should also be developed based on this understanding. Therefore, this study aimed to present agricultural Best Management Practices (BMPs) applicable for the fields based on the Delphi survey result. METHODS AND RESULTS: This study deduced the evaluation items to assess each BMP for agricultural NPS control and conducted the surveying using the Delphi method based on agricultural BMP experts. In addition, its on-the-spot application were evaluated. Considering its importance, technical, social and economic proprieties showed that political support was ranked first and followed by cost investment, labor investment, reduction effect and resident participation. The survey findings by agricultural BMP experts showed the good performance of on-the-spot application can be achieved from fertilization by soil testing, residue and green manure application and contour plowing which are applicable within a field. Agricultural BMPs, highly applicable for the fields, were the countermeasures that farmers who are the principal bodies of agricultural NPS control could be participated directly. CONCLUSION: The active participation of farmers is essential for effective control of agricultural NPS. It is necessary to establish various incentive systems.

• Spatial Information Research
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• v.19 no.6
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• pp.87-100
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• 2011

Recently, a variety of GML application schemas have been designed in many fields. GML application schemas are specific to the application domain of interest and specify object types using primitive object types defined in the GML standard. GML instance documents are created based on such GML application schemas. The GML instance documents generally require large volumes to represent huge amounts of geographic objects. Thus, it is essential to store such GML instance documents in relational database for efficient management and use. Relational database is relatively convenient to use and is widely applied in various fields. Furthermore, it is fundamentally more efficient than file structure to handle large datasets. Many researches on storing GML documents have been carried out so far. However, there are few studies on storage of GML instance documents. Therefore, in this study, we developed the storage module to store the GML instance documents in relational database.

• Korean Journal of Child Studies
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• v.20 no.3
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• pp.183-197
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• 1999

A pilot education program was developed, applied in a practical setting, and evaluated. The program was designed on the basis of various educational philosophies and characteristics of parents as learners in various developmental stages. Specialists in the fields of parent education, early childhood education and child development were consulted. The comparative results between the pre- and post-tests of parent behaviors demonstrate that this program has a positive influence on the behaviors of participating patents. It was concluded that this program can be applied usefully in the development of and application to various parent education programs in Korea.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.71-76
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• 1998

Water management objects was developed using the Object Oriented Programming (OOP) concept and Irrigation Block Simulation Model was developed using these objects. This model using OOP can simulate the behavior of the irrigation block composed of several irrigation canals, drainage canals, paddy fields, check gates, and so on. This study showed that using OOP concept, we can develop an water management application or extend the function of existing application more easily.