• Journal of Korean Society for Quality Management
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• v.46 no.3
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• pp.425-440
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• 2018

Purpose: This study is aimed at developing of the flex resistance testing process at low temperature with the waterproof fabric to suit the military environment, and is designed to fit for the purpose of the waterproof materials in order to optimize the test method by finding out matters to improve from existing the test method and through previous studies. Methods: The test method, which has been applied to flex resistance of existing water-repellent materials, was improved and consequently, differentiated test results could be obtained according to the test temperature, sample size, and flexing method. Results: The testing of the total of 8 samples revealed that performance of the military requirement could hardly be met just by presenting the materials or 2~3 layers when the quality criteria for high functional water repellent fabrics were applied. PTFE(Polytetrafluoroethylene) is preferred to PU(Polyurethane) to be used in the extremely low-temperature environment, but durability under the low-temperature environment may be varied depending on film thickness or laminating technique even if the materials of waterproof films are identical. Therefore, in addition to the material or texture, the test method capable of reflecting durability under the low-temperature environment shall be suggested, and the newly designed test method proposed in this study was shown to suggest differentiated quality criteria by the material. Conclusion: The water resistance measurement and the test method following flex resistance with expanded range of flex will enable the differentiable test of the samples according to the number of repetition. This study is meaningful in that it suggests a differentiable test method capable of establishing a basis of deciding suitable material when selecting military goods made of water repellent material by properly improving the test method.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.3
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• pp.259-265
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• 2009

This paper studies the Element Connectivity Parameterization Method(ECP method) for topology optimization considering dynamic compliance. The previous element density based topology optimization method interpolates Young's modulus with respect to design variables defined in each element for topology optimization. Despite its various applications, these element density based methods suffer from numerical instabilities for nonlinear structure and multiphysics systems. To resolve these instabilities, recently a new numerical method called the Element Connectivity Parameterization(ECP) Method was proposed. Unlike the existing design methods, the ECP method optimizes the connectivities among plane or solid elements and it shows some advantages in topology optimization for both nonlinear structure and multiphysics systems. In this study, the method was expanded for topology optimization for the dynamic compliance by developing a way to model the mass matrix in the framework of the ECP method.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.11a
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• pp.23-32
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• 2004

This paper describes a new estimation method for deviation coefficients, B and C. using only measured single deviation at a fixed compass bearing. At first, some problems in the deviation synthesis with only two coefficients, B and C, are discussed using observed deviation values measured in the four USS warships. Then, acquisition theories and procedures to obtain optimal coefficients, B and C, are expanded and then the efficiencies of the proposed prediction method are evaluated. As results from evaluations, it is shown that the approximated coefficients, B and C, can give optimal approximation to observed single deviation.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.3
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• pp.42-48
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• 2002

Multiple description coding Is source coding for multiple channels such that a decoder which receives an arbitrary subset of the channels may produce a useful reconstruction. This paper presents an efficient multiple description coder using a newly designed EZW coding method. We first propose EZW coder which has expanded threshold and two subordinate passes. And then we present multiple description coder which has two coding channels using the proposed EZW coders. To evaluate the performance of the proposed coder, we provide an image coding applications with two descriptions and compare multiple description image coding results reported to date. Simulation results show that the proposed method has a better performance than the polyphase transform method.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.6
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• pp.61-67
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• 2011

Stereoscopic 3D video can be transmitted by frame-compatible packing format to fulfill the compatibility requirement with the existing digital TV. Then, the reduced stereo image needs to be expanded to the original size at the receiver. This paper proposes an adaptive interpolation method for the discarded image lines. The horizontal line-based linear filter and NEDI6 filter are used selectively for the interpolation of each pixel. Experimental results show that the NEDI6 combined with the horizontal line-based linear filter yields better image quality than the bilinear method by around 0.6dB.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.1
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• pp.120-126
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• 1991

An expanded scheme of a direct numerical solution method for solving the Navier-Stokes equation considering the modified boundary conditions for gas lubrication with ultra low clearance at high .LAMBDA. region is presented. Many examples are calculated by this scheme and their results are compared to the previous solutions using P$^{2}$H$^{[-992]}$ . This scheme has the advantages of fast calculation time and stable convergence in high .LAMBDA. region, and gives very good results in the case of fluid film thickness discontinuity.

• The Journal of the Korea Contents Association
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• v.5 no.1
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• pp.19-26
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• 2005

This paper introduces a new design method of realizing the machine control interface by using bio-signals(EEG/EOG). This method can be further expanded to be applied to the computer system responding to EEG or EOG signals and the general bio-feedback system. For this reason, we made the remotely controlled toy system controlled by the EEG spectrums, their combination indexes, and EOG parameters. And the headset that has bio-signal processing modules built-in offers convenience for users, and this make much more advanced system than any other existing BCI and BMI system.

• Journal of the Korea Computer Industry Society
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• v.3 no.9
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• pp.1287-1294
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• 2002

The algorithm method for progressive image coding based on discrete wavelet transform presented in a paper. After discrete wavelet transform and extract edge information through edge detection, and then designed efficient coding method more then established embedded coding algorithm using expanded EZW algorithm. Generally, edges have a relatively higher influence on image reconstruction. Occurred DWT on image, and can classify significant coefficients and non-significant coefficients. Using property that edge part has appeared significant coefficient in the paper. Especially, we confirmed that higher frequency sub region on DWT image present homogenous direction property. And on embedded coding, which are effective and well-directed information have higher priority to image reconstruction on transmission. Therefore, our technique algorithm system perform better than that of the conventional method such as progressive image coding application.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.2
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• pp.353-360
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• 1997

In this paper, we propose a new blocking method in which the size of an encryption block is changed according to the size of a message block. The proposed method can be applied to multisignature scheme with no restrictio of the signing order and a multisignature anc be sent secretly to the receiver through RSA encryption. It causes expansion in block size of a multisignuture, but the length of the expanded bits is not greater than the number of signers regardless fo the bit lengths of RSA moduli.

• Spatial Information Research
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• v.11 no.4
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• pp.509-518
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• 2003

Impervious surface affects urban climate, flood, and water pollution. With a higher paved rate, expanded heat containing capacity of buildings and roads raises atmospheric temperature, and increased quantity of the outflowed water brings flood during a heavy downpour. Moreover, increased non-point source pollutant load is accountable for water pollution. In this regard, it is definitely important to research and keep monitoring the current situation of paved surface, which influences urban ecosystem, disaster and pollution. In fact, collecting information on urban paved surface, which requires the time and expense, is very difficult due to its complicate structure. In order to solve the problem, this study suggested a method to utilize satellite image data for efficient survey on the current condition of paved surface. It analyzed the paved surface condition of Anyang-si by using IKONOS image and discussed the usefulness and limitation of this method.