• Journal of KIISE:Software and Applications
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• v.33 no.2
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• pp.154-166
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• 2006

Product Line Engineering(PLE) is a software reuse paradigm that core assets are defined using common features in a domain and are instantiated in various applications. To apply the core asset effectively, variants which satisfy application requirements are extracted and the core asset should be also instantiated based on the variants. For the work, variability on architecture and components should be extracted exactly and an instantiation process and guidelines should be defined based on this variability In this paper, we define variability types depending on core assets elements and describe artifact templates related to tile variability. We also propose a systematic process which uses defined core assets including variability and verify practicability of the proposed process and variability expression through doing ease study. If utilizing with the proposed process in PLE, it can be feasible to model concrete core asset and variability and to utilize practical application engineering.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.3
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• pp.299-305
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• 2010

In general, the flexible forming die that has been used in the flexible forming process has the identical punch size; hence, its flexibility is relatively low because the range of allowable curvature radii is limited due to the uniform punch tip radius. Hence, a conceptual design of a sectional flexible die is presented for enhancing the flexibility of the forming process. Two punches of different sizes are used to configure the arbitrary forming surface. For a forming region with a relatively large curvature radius, a large punch array block is used; on the other hand, for the forming regions with small curvature radii, a small punch block is used. The cross-sectional profiles are compared with the target shape for evaluating the effectiveness of the process. Consequently, it is confirmed that the sectional flexible die can be used along with a combination of punch blocks of different sizes for manufacturing objective surfaces of complex shapes.

• Journal of Advanced Navigation Technology
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• v.16 no.6
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• pp.1038-1043
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• 2012

In this work, a high tunable capacitor using a multi-layer dielectric of BZN/BST/BZN is designed and characterized for reconfigurable RF applications. By utilizing a high tunable BST ferroelectric and a low-loss BZN paraelectric thin film, a multi-layer dielectric of BZN/BST/BZN obtained a tunability of 47 % and $tan{\delta}$ of 0.005. The fabricated tunable capacitor on a quartz wafer using this multi-layer dielectric achieved a Q-factor of 10 and tunability of 60 % at 800 MHz and 15 V. Its size is $327{\times}642{\mu}m2$.

• Spatial Information Research
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• v.18 no.5
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• pp.13-26
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• 2010

In this paper, a dynamic variable window-based topographical classification method is proposed which has the changeable classification units depending on topographical properties. In the proposed scheme, to im prove the classification efficiency, the unit of topographical classification can be changeable dynamically according to the topographical properties and repeated patterns. Also, in this paper, the classification efficiency and accuracy of the proposed method are analyzed in order to find an optimal maximum decision window-size through the experiment. According to the experiment results, the proposed dynamic variable window-based topographical classification method maintains similar accuracy but remarkably reduce computing time than that of a fixed window-size based one, respectively.

• The Journal of the Acoustical Society of Korea
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• v.20 no.7
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• pp.47-54
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• 2001

In this paper, we present a variable dimension vector quantization for spectral magnitudes. Espectially, spectral magnitudes of the Harmonic coder, need variable dimension quantizer because those are not fixed dimension. So, this paper present efficient quantization methods. These methods use variable Discrete Cosine Transform(DCT) for spectral magnitude parameters and NSTVQ which is combined odd/even, split and multi-stage structure, proposed quantization methods use Spectral Distortion(SD) for performance measure. Consequently, Multi-Stage Nonsquare Transform Vector Quantization(MSNSTVQ) is the best in performance measure.

• Journal of the Korea Society of Computer and Information
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• v.17 no.11
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• pp.19-26
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• 2012

Reversible lanes in urban intersections is used to efficiently control vehicles, reduce traffic congestion and increase the capacity of a roadway. But by far traffic control systems in urban intersections are simple and manually operated by police officers. In this study, we present a hybrid algorithm that intelligently resolve the moving direction of reversible lanes to efficiently manage the flow of traffic at intersection. The proposed algorithm consists of three stages:(i) fuzzy inference method to get the efficiency of moving direction, (ii) a provisional decision whether to change the reversible lane to different direction, (iii) a final evaluation criterion for changing the directions of the reversible lanes. The fuzzy inference results of efficiency are shown by using matlab application.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.2
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• pp.68-74
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• 2001

A design and implementation method for the UHF-band(800MHz) variable attenuator using the 3dB coupler is proposed. The 90 degree, 3-dB Coupler is used for the variable attenuator. The principal theory for the 3-dB coupler is introduced. The 3-dB Coupler is designed by the mathematical analysis and a computer simulation tool. A PIN diode is used for the variable resistor at UHF-band. The variable attenuator using the 3-dB coupler and the PIN diode is designed and implemented. The measured results for the variable attenuator by a network analyzer show that the insertion loss is below -l0dB, and the continuous variable attenuation range is about 10dB.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.10
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• pp.1195-1200
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• 2013

In recent years, variable stiffness actuation has attracted much attention because interaction between a robot and the environment is increasingly required for various robot tasks. Several variable stiffness actuators (VSAs) have been developed; however, they find limited applications owing to their size and weight. For realizing their widespread use, we developed a compact and lightweight mini-VSA. The mini-VSA consists of a control module based on an adjustable moment arm mechanism and a drive module with two motors. By controlling the relative motion of cams in the control module, the position and stiffness can be simultaneously controlled. Experimental results are presented to show its ability to change stiffness.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.3
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• pp.19-32
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• 2000

This paper suggests the variable structure controller with a new variable boundary layer for the accurate tracking control of the variable structure systems. Up to now, variable structure controller (VSC) applying the variable boundary layer did not remove chattering from an arbitrary initial state of the system trajectory because VSC has the limited initial state according to the fixed sliding surface. But, by using the linear time-varying sliding surfaces, the scheme has the robustness against chattering from all states. The suggested method can be applied to the second-order nonlinear systems with parameter uncertainty and extraneous disturbances, and has better tracking performance than the conventional method. To demonstrate the advantages of the proposed algorithm, it is applied to a two-link manipulator.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2003.11a
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• pp.133-138
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• 2003

가변길이 부호는 정보원(source)의 통계적인 특성을 이용하여 부호화 효율을 높이지만. 잡음이 심한 전송환경에선 비트에 대한 오류가 발생하면 심각하게 손상되는 단점을 가진다. 이러한 가변길이 부호의 문제를 해결하기 위해 양방향 가변길이 부호가 제안되었다. 양방향 가변길이 부호는 순방향과 역방향으로 복호가 가능하여 전송 오류로 인해 손상된 비디오 비트열에서 데이터를 복구할 수 있다. 부호의 자유거리(free distance)는 부호자체가 전송 오류에 얼마나 강인한지를 보여주는 척도로 사용된다. 양방향 가변길이 부호의 자유거리(free distance)의 최소 값은 1이므로 비디오 비트열 손상 자체를 방지할 수는 없다 본 논문에서는 자유거리(free distancs)의 최소 값을 증가시켜 전송오류에 더욱 강인한 새로운 양방향 가변길이 부호의 선계 기법을 제안한다. 제안된 알고리즘은 주어진 Huffman 부호와 평균부호길이 함수의 특성을 이용하여 자유거리의 조건을 만족하면서 동시에 부호화 효율을 높여 기존의 알고리즘보다 향상된 성능을 보여준다.