• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.613-615
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• 2005

모바일 기기가 가지는 다양한 화면 사이즈 등을 고려한 정보 서비스를 제공하기 위해서는 비트맵 기반의 JPG나 GIF 보다는 벡터 기반의 SVG, Flash Lite와 같은 이미지 포맷이 더 적합하다. 대부분의 모바일 기기의 경우 작은 메모리, 협소한 네트워크 대역폭, 불안전한 네트워크 연결 등과 같은 제약성을 가지고 있기 때문에 모바일 기기와 서버 간의 정보나 데이터의 망과 전송 시간을 단축시키기 위한 다양한 연구들이 진행되고 있다. 이에 본 논문에서는 모바일 기기에서 정보를 표현하기 위하여 사용되는 SVG와 같은 XML 파일들을 효과적으로 전송하기 위한 방법을 제안한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04a
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• pp.663-666
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• 2002

임베디드 리눅스의 개발은 커널과 각 시스템 응용들을 자신이 원하는 플랫폼에 맞추어 일일이 수작업으로 설정, 컴파일, 타겟에의 인스톨 과정을 거쳐야 한다. 이것은 실제 타겟에 필요한 응용 개발에 앞서 많은 개발 시간을 소요하게 하며, 또한 그 과정 중 많은 시행착오의 반복을 야기하게 한다. Qplus 타겟 빌더는 임베디드 리눅스 개발 과정 중 설정 가능한 사항들을 옵션화하여 개발자가 통합된 환경에서 커널과 응용을 세세하게 설정할 수 있게 하며, 각 옵션들간의 의존성을 자동으로 검사함으로써 타겟에 적합한 설정을 할 수 있게 도와준다. 또한 타겟에 적재(deployment)될 수 있는 형태로 루트파일 시스템을 자동 생성하고 라이브러리 최적화를 통해 사이즈를 최적화시킨다. Qplus 타겟빌더는 인터렉티브한 타겟 시스템 설정과 자동화된 타겟에의 적재로 임베디드 리눅스의 개발 시간을 단축시켜 준다.

• Journal of the Institute of Convergence Signal Processing
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• v.14 no.2
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• pp.95-98
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• 2013

The LMS(Least Mean Square) algorithm, one of the most famous, is generally used because of tenacity and high mating spots and simplicity of realization, But it has trade-off between nonuniform collection and EMSE(Excess mean square error). To overcome this weakness, a variable step size is used widely, but it needs a lot of calculation loads. In this paper, we suggest changed algorithm in case of environment changes of cars and reduce amount of calculation as it uses original signal and noise signal of IGC(Instantaneous Gain Control) algorithm. In this paper, logarithmic function is removed because of real-time processing IGC. The performance of proposed algorithm is tested to adaptive noise canceller in automobile.

• Journal of the Korean Society of Clothing and Textiles
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• v.41 no.1
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• pp.184-195
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• 2017

Baseball is a life sport that gives vitality to people. However, currently available leg guards do not have a variety of sizes and it is very difficult to purchase a leg guard that is suitable for the size of a specific consumer. Therefore, this study investigated the size system of a leg guard sold in the market and suggested a grading deviation suitable for the legs of Korean males. The results of the study were as follows. First, most brands were sold only in three size systems as children's, teenagers, and adults. Adult size systems were not subdivided. Second, Korean male legs were classified into Group 1 (large girth and height and lower body muscle) and Group 2 (small girth and height and low underbody muscle). Third, the size system is based on vertical items such as height and mid-thigh circumference. Each group produced 10 sizes. The smallest height or the largest height was also found to be about 4.5 to 5.0cm smaller or larger than the sample size for each group. The total length of the leg guard was about 2.5cm when the height was increased or decreased by one size. It was confirmed that the deviation of the circumference of the mid-thigh should be about 2.0cm larger or smaller than the sample size even if the height is the same. The deviation of the knee circumference and ankle circumference was smaller than the other circumference. In conclusion, the dimension combinations of the leg guard must be set differently to provide a leg guard with high size suitability according to leg type.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.3
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• pp.545-550
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• 2016

The main purpose of this study is to analyze and evaluate the feasibility of ligthweight pavement system with pile foundation on soft soil by laboratory small chamber test. In order to verify the stability of lightweight pavement system, the 1/30 scaled downed model system was tested at lab. The soft soil condition was simulated and group piles for skin friction resistance were used. Within the limited lab test, the settlements of pavement system were 0.86 mm for Case A, 0.70 mm for Case B, and 0.50 mm for Case C. The converted maximum settlement differential settlement were 25.8 mm and 10.8 mm. These values meet the inside of specification of Bridge Design Guide in Korea. The use of lightweight pavement systems on soft soils could be an alternative construction method on soft soils to reduce the challenges of conventional design and constructions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.645-652
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• 2016

The statistical modeling of input random variables is necessary in reliability analysis, reliability-based design optimization, and statistical validation and calibration of analysis models of mechanical systems. In statistical modeling methods, there are the Akaike Information Criterion (AIC), AIC correction (AICc), Bayesian Information Criterion, Maximum Likelihood Estimation (MLE), and Bayesian method. Those methods basically select the best fitted distribution among candidate models by calculating their likelihood function values from a given data set. The number of data or parameters in some methods are considered to identify the distribution types. On the other hand, the engineers in a real field have difficulties in selecting the statistical modeling method to obtain a statistical model of the experimental data because of a lack of knowledge of those methods. In this study, commonly used statistical modeling methods were compared using statistical simulation tests. Their advantages and disadvantages were then analyzed. In the simulation tests, various types of distribution were assumed as populations and the samples were generated randomly from them with different sample sizes. Real engineering data were used to verify each statistical modeling method.

• The Journal of Korean Institute of Information Technology
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• v.15 no.12
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• pp.157-164
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• 2017

Mobile ECG signal measurement is a technique to measure small signals of several mV, and many studies have been conducted to remove noise including wandering scheme. Removal of the equipotential line noise caused by shaking or movement of the electrode cable is one of the core research contents for the electrocardiogram measurement. In this study, we proposed a modified step-size of combined NLMS(normalized least squares) and DLMS(delayed least squares) adaptive filter to eliminate baseline noise from ECG signals. The proposed method mainly adjusts initial filter step-size to reduce distortion of original ECG signals characteristic after eliminating baseline noise. The modified filter step-size is scaled by filter order size and distortion minimization factor. This method is suitable for portable ECG device with a small processor and less power consumption. This technique also decreases computation time which is essential for real-time filtering. The proposed filter also increase the signal to noise ratio (SNR) compared to conventional NLMS filter.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2008.11a
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• pp.199-202
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• 2008

고객의 통신 니즈가 다양해지고 통신 인프라가 대용량, 고속화 되고 단말이 지능화됨에 따라 이를 기반으로 IPTV의 셋탑, 컴퓨터 모니터, 이동통신 핸드폰이 이르기 까지 다양한 화면 사이즈의 단말을 통하여 서비스를 제공하고 있다. 이를 위해 원영상을 화면의 크기에 적합하게 크기를 변환하는 영상 리사이징 기술을 이용하게 되며, 그 방식은 DCT 방식과 공간 방식으로 나눌 수 있다. DCT방식은 원영상의 고주파 영역의 조정하여 크기를 변화하는 방식으로 열화는 최소화되나 DCT 변환을 위한 계산량이 많고 고정 크기 블록을 사용하므로 유연성이 떨어진다. 공간영역은 객관적인 평가에서 품질이 열화되더라도 시각적으로 눈에 민감한 영역의 변화를 최소화하는 것이다. 본 논문은 인간시각시스템을 기반으로 눈의 민간도가 높은 망막 이심율이 작은 영역에서는 DCT블록의 크기를 변화를 최소화시키고 망막이심율이 큰 영역에서는 블록의 변화를 크게 하는 가변 블록방식을 제안한다. 이를 통해 우수한 영상 품질을 확보하면서도 시각적으로 뛰어난 리사이징 영상을 얻을 수 있다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.5
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• pp.51-56
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• 2008

In this paper, we propose a printed planar antenna suitable for mobile wireless communications. Since the printed antenna is easy to fabricate due to simplicity, low cost, and light weight, it is widely used in communications systems. The conventional patch antenna takes too much surface area to be applied to a mobile receiver. Although the size is reduced using the printed antenna, still reasonably wide bandwidth should be considered. To overcome the disadvantage of narrow bandwidth, the substrate should be physically thick and the dielectric constant should be small. In this work, we suggest a simple form of printed planar antenna and show the optimal input impedance depending on the antenna size and operating frequency. The performance evaluation is achieved analytically for a prototype antenna model.

• Journal of Korean Society of societal Security
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• v.4 no.1
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• pp.49-55
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• 2011

The primary objective of this paper is to develop optimal algorithms of reinforced concrete frame structural systems by the limit state design(CP 1110) and to look into the possibility of detailed design of these structural systems. The structural formulation is derived on the finite element method. The objective of optimization of a reinforced structure for a specified geometry is mainly to determine the optimum cross-sectional dimensions of concrete and the area of the various sizes of the reinforcement required for each member. In addition to the detail s such as the amount of web reinforcement, cutoff points of longitudinal reinforcedments etc. are also considered as design variables. In this study, the method of "Generalized Reduced Gradient, Rounding and with Neighborhood search" and "the Sequential Linear Programming" are employed as an analytical method of nonlinear optimization.