• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.977-979
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• 1996

This paper presents an algorithm to control the undesirable sway of a suspended load in the crane system that has a trade-off between positioning the load and suppressing the sway of the load. The aim is to transport the load to a specified place with small sway angle as quickly as possible. Dynamic model is based on a simple pendulum driven by a velocity drive that is mostly used for actuating a trolley in industry. Proposed algorithm is composed of two parts : one is a off-line optimal trajectory generator, the other on-line tracking control. The former produces optimal trajectories minimizing energy under the speed constraint of velocity drive. The latter controls outputs to track the generated trajectories. Digital simulations and experiments are performed on a pilot crane to demonstrate the performance of the proposed control algorithm.

• International Journal of Aeronautical and Space Sciences
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• v.3 no.1
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• pp.39-49
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• 2002

This paper presents a robust tracker design method that is specific to the trajectories of target aircraft. This method assumes that representative trajectories of the target aircraft are available. The exact trajectories known to the tracker enables the incorporation of the exact data in the tracker design instead of the measurement data. An estimator is designed to have acceptable performance in tracking a finite number of different target trajectories with a capability to trade off the mean and maximum errors between the exact trajectories and the estimated or predicted trajectories. Constant estimator gains that minimize the cost functions related to the estimation or prediction error are computed off-line from an iterative algorithm. This tracker design method is applied to the longitudinal motion tracking of target aircraft.

• Journal of KIISE:Computing Practices and Letters
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• v.13 no.4
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• pp.231-239
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• 2007

This paper presents the trade-off relationship between area and performance in the hardware design space exploration for the Korean national standard 128-bit block cipher algorithm SEED. In this paper, we compare the following four hardware design types of SEED algorithm : (1) Design 1 that is 16 round fully pipelining approach, (2) Design 2 that is a one round looping approach, (3) Design 3 that is a G function sharing and looping approach, and (4) Design 4 that is one round with internal 3 stage pipelining approach. The Design 1, Design 2, and Design 3 are the existing design approaches while the Design 4 is the newly proposed design in this paper. Our new design employs the pipeline between three G-functions and adders consisting of a F function, which results in the less area requirement than Design 2 and achieves the higher performance than Design 2 and Design 3 due to pipelining and module sharing techniques. We design and implement all the comparing four approaches with real hardware targeting FPGA for the purpose of exact performance and area analysis. The experimental results show that Design 4 has the highest performance except Design 1 which pursues very aggressive parallelism at the expanse of area. Our proposed design (Design 4) shows the best throughput/area ratio among all the alternatives by 2.8 times. Therefore, our new design for SEED is the most efficient design comparing with the existing designs.

• Proceedings of the Korean Society for Quality Management Conference
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• 1998.11a
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• pp.531-543
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• 1998

TRIZ, the Russian acronym for Theory of Inventive Problem Solving(TIPS) is introduced in this paper. The core concepts of TRIZ such as levels of inventions, patterns of technological evolution, technical and physical contradictions are explained. It is also discussed that how TRIZ can be applied to quality function deployment in order to overcome negative correlations(i.e., trade-off relationships) between engineering characteristics. Some case examples are presented for the purpose of explanation.

• JOURNAL OF ELECTRICAL WORLD
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• s.325
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• pp.36-39
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• 2004

프로젝트 관리는 통합적인 노력으로 수행되어 어떤 분야에 대한 특정의 조치 또는 불이행은 다른 분야에 영향을 미치게 된다. 즉 프로젝트 범위의 변경은 거의 대부분 프로젝트의 원가에 영향을 미치게 되지만 팀 사기나 품질에는 영향을 미칠 수도 있고, 그렇지 않을 수도 있다. 이와 같은 상호작용은 종종 프로젝트 목표들 간의 다음 그림과 같이 상호절충(Trade-Off)을 필요로 하여, 특정 분야의 성과가 다른 분야의 성과를 희생해야만 향상될 수 있는 경우도 생길 수 있기 때문이다. 한 프로젝트의 성공적인 관리는 이와 같은 상호작용의 적극적인 관리를 필요로 한다.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10a
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• pp.296-298
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• 1998

본 논문의 폭주적인(bursty) 트래픽을 생성하는 스트리밍에서 사용자가 요구하는 최소 품질 (Quality of Service)의 보장 및 공정한 대역폭 활용을위하여 개선된 대역폭 적응 기법을 제안한다. LAN상의 서버/클라이언트 유니캐스트 환경에서 수행된 시뮬레이션은 제안한 기법에 의한 전송율의 패턴이 네트워크의 일시적인 혼잡에 의한 영향이 적고 안정하며 대역폭을 공유하는 기타 커넥션들에게 공정하도록 대역폭을 활용함을 보여준다. 제안한 대역폭 적응 기법에 사용한 윈도우 기반 전송율 추정은 윈도우 크기에 따라 스트리밍 어플리케이션의 graceful degradation과 대역폭 활용의 trade-off을 갖고 있지만 세션 중 윈도우 크기를 상황에 따라 동적으로 변화시킴으로 요구사항을 충족하도록 응용될 수 있다.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1387-1390
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• 1997

In this paper we propose a novel way to restore degraded image using wavelet transform & filterbank. First, we devide a degraded image into 4-suband images using UDWT(Undecimated Wavelet Transform), and then use a proper CLS (Constrained Least Square) filter in each subband. Using a proper CLS filter ineach subband, we can save high grequency components of original image. We reconstruct a restored image from the downsampled subband images using wavelet tansform. Even though there is a trade-off between ISNR and calculation loads, we reduce the calculation loads by using wavelet transform in reconstruction with a negligible degradatiion in ISNR.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1293-1296
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• 1997

We investigate a design methodology for master arm which is employed in remote-site control. Though counter-balancing has been employed for the purpose of lessening the actuator loads, it results in the increase of dynamic load at the task position. Therefore, there exist a trade-off between counter-balacing and dynamic performance. The concept of a composite index is introduced to simulataneously consider those two effects in the design of master arms. Several alternative designs of master arms are suggested.

• Proceedings of the IEEK Conference
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• 2001.06d
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• pp.77-80
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• 2001

In this paper, we have introduced a new watermarking method using the Discrete Wavelet Transform (DWT). This method has two features. Firstly the trade-off between the quality and the robustness, and between the quality and the capacitance can be controlled. Next, this method use different scheme according to the watermarks. We have also implemented numerical examples for several kinds of attack. It is found that watermarking method in this paper is robust to above attacks.

• Proceedings of the CALSEC Conference
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• 1997.11a
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• pp.319-332
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• 1997

. 개발 비용 감소 - 컨설팅 비용 감소 - 쉬운 적합화 방법론 ㆍSlim화 - 업무 기능 체계의 Template화 -업체/업종별 필수 기능 위주 ㆍ개발 기간 축소 - 표준 프로세스 활용 - 특성치를 적용한 방법론개발 ㆍEIS 강조 ㆍFlexible - 표준 프로세스와 기업 특유의 프로세스간의 trade-off 문제 - 기업 전략 및 기반 구조에 따른 해결 ㆍ점진적인 BPR(중략)