• Communications for Statistical Applications and Methods
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• v.15 no.6
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• pp.959-967
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• 2008

In this paper we show the weak convergence of the linear random(multistochastic process) field generated by identically distributed 2-parameter array of associated random variables. Our result extends the result in Newman and Wright (1982) to the linear 2-parameter processes as well as the result in Kim and Ko (2003) to the 2-parameter case.

• Journal of the Korean Magnetic Resonance Society
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• v.3 no.2
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• pp.71-83
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• 1999

The dynamics of the dipolar demagnetizing field is investigated by numerical simulation. The effects of radiation damping, molecular diffusion, and relaxation processes on the dipolar demagnetizing field are examined in terms of the modulation pattern of the z-magnetization and the signal intensity variation. Simulations for multi-components suggest applications for sensitivity enhancement in favorable conditions.

• KIEE International Transactions on Electrophysics and Applications
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• v.2C no.6
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• pp.287-291
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• 2002

Measurement technique of three dimensional electric field distribution in liquid dielectrics have been studied. Kerr effect and computed tomography(CT) method have been used. Measuring time has been shortened by the use of multi-optical systems to less than several milliseconds. Near future, electric field distribution in front of a streamer tip of breakdown would be measured.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2007.02a
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• pp.58-60
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• 2007

The availability of Information Technology in geological and engineering geological fields is rapidly increasing in Korea. Especially GIS-based hazard mapping is the most distinctive part to predict a possibility of landslide occurrence. Integrated expert system for tunnel construction is also practically used to manage investigated or designed data and to predict un-known underground geological condition. Computer-based field data acquisition tools are also one of the typical part using information technology including GIS combined with mobile phone in Geological field.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.138-143
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• 2000

CREAMS-PADDY model for simulating daily water and nutrient balance at irrigated paddies was developed, applied to, and validated with field data. The model simulates daily flooding depth and total nitrogen and phosphorus concentrations from meterorological, irrigation, and farming data. Simulated results from the model were in good agreement with field data. Among different scenarios to reduce nutrient losses from paddies, the water management was found to be very effective, and recommended for field applications.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10b
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• pp.861-866
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• 1998

This study is numerical procedure of strengthening capacity in a field structure and compare analysis data with test data. Recently, many strengthening methods are developed and used to rehabilitate existing structure. However, both theoretical background and applying techniques are not established yet. One of the most popular method is plate bonding method using either steel plate or carbon plate. This theoretical background and applying techniques are very important and those applications are differed when applied in field strengthening cases. Also depending on the analysis out come, displacement increased based n the condition of members while reaching ultimate load or failure load.

• Journal of the Korea Safety Management & Science
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• v.3 no.4
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• pp.65-76
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• 2001

Field data have been recorded as the time to failure or the number of failure of systems. We consider the time to failure and covariate variables in some pre-specified follow-up or warranty period. This paper aims to investigate study on the reliability estimation when some additional field data can be collected within-warranty period or after-warranty period. A various likelihood-based methods are outlined and examined for exponential or Weibull distribution.

• Journal of Broadcast Engineering
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• v.12 no.2
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• pp.185-192
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• 2007

The interpolation is used in many image processing applications such as image enhancement, de-interlacing/scan-rate conversion, wavelet transforms based on the lifting scheme, and so on. Among these, de-interlacing and scan-rate conversion are proposed for the digital TV applications. The de-interlacing algorithm can be classified into two categories. The first one uses only one field, called intra-field de-interlacing, and the other uses multiple field, called inter-field de-interlacing. In this paper, an efficient de-interlacing algorithm using spatial domain information is proposed far the interpolation of interlaced images. By efficiently estimating the directional correlations, improved interpolation accuracy has been achieved. In addition, the proposed method is simply structured and is easy to implement. Extensive simulations conducted for various images and video sequences have shown the efficacy of the proposed method with significant improvement over the previous intra-field do-interlacing methods in terms of the objective image quality as well as the subjective image quality.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.1062-1073
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• 2007

Acoustic Target Strength (TS) is a major parameter of the active sonar equation, which indicates the ratio of the radiated intensity from the source to the re-radiated intensity by a target. In developing a TS equation, it is assumed that the radiated pressure is known and the re-radiated intensity is unknown. This research provides a TS equation for polygonal plates, which is applicable to near field acoustics. In this research, Helmholtz-Kirchhoff formula is used as the primary equation for solving the re-radiated pressure field; the primary equation contains a surface (double) integral representation. The double integral representation can be reduced to a closed form, which involves only a line (single) integral representation of the boundary of the surface area by applying Stoke's theorem. Use of such line integral representations can reduce the cost of numerical calculation. Also Kirchhoff approximation is used to solve the surface values such as pressure and particle velocity. Finally, a generalized definition of Sonar Cross Section (SCS) that is applicable to near field is suggested. The TS equation for polygonal plates in near field is developed using the three prescribed statements; the redection to line integral representation, Kirchhoff approximation and a generalized definition of SCS. The equation developed in this research is applicable to near field, and therefore, no approximations are allowed except the Kirchhoff approximation. However, examinations with various types of models for reliability show that the equation has good performance in its applications. To analyze a general shape of model, a submarine type model was selected and successfully analyzed.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.466-466
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• 2011

There have been several methods to fabricate carbon nanotube (CNT) emitters, which include as-grown, spraying, screen-printing, electrophoresis and bonding methods. Unfortunately, these techniques generally suffer from two main problems. One is a weak mechanical adhesion between CNTs and the cathode. The as-grown, spraying and electrophoresis methods show a weak mechanical adhesion between CNTs and the cathodes, which induces CNT emitters pulled out under a high electric field. The other is a severe degradation of the CNT tip due to organic binders used in the fabrication process. The screen-printing method which is widely used to fabricate CNT emitters generally shows a critical degradation of CNT emitters caused by the organic binder. Such kinds of problems induce a short lifetime of the CNT field emitters which may limit their practical applications. Therefore, a robust CNT emitter which has the strong mechanical adhesion and no degradation is still a great challenge. Here, we introduce a simple and effective technique for fabrication of CNT field emitter, namely filtration-taping-transfer method. The CNT emitters fabricated by the filtration-taping-transfer method show the low turn-on electric fields, the high emission current, good uniformity and good stability. The enhanced emission performance of the CNT emitters is mainly attributed to high emission sites on the emitter area, and to good ohmic contact and strong mechanical adhesion between the emitters and cathodes. The CNT emitters using a simple and effective fabrication method can be applied for various field emission applications such as field emission displays, lamps, e-beam sources, and x-ray sources. The detail fabrication process will be covered at the poster.