• 한국CDE학회논문집
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• 제2권3호
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• pp.175-185
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• 1997

Given the widespread use of the Finite Element Method in strength analysis, automatic mesh generation is an important component in the computer-aided design of parts and assemblies. For a given resolution of geometric accuracy, the purpose of mesh generators is to discretize the continuous model of a part within this error limit. Sticking to this condition often produces many small elements around small features in spite that these regions are usually of little interest and computer resources are thus wasted. Therefore, it is desirable to selectively suppress small features from the model before discretization. This can be achieved by low-pass filtering a CAD model. A spatial function of one dimension higher than the model of interest is represented using the Fourier basis functions and the region where the function yields a value greater than a prescribed value is considered as the extent of a shape. Subsequently, the spatial function is low-pass filtered, yielding a shape without the small features. As an undesirable effect to this operation, all sharp corners are rounded. Preservation of sharp corners is important since stress concentrations might occur there. This is why the LPF (low-pass filtered) model can not be directly used. Instead, the distances of the boundary elements of the original shape from the LPF model are calculated and those that are far from the LPF model are identified and removed. It is shown that the number of mesh elements generated on the simplified model is much less than that of the original model.

• IEIE Transactions on Smart Processing and Computing
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• 제3권2호
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• pp.41-51
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• 2014

This paper describes a method to estimate the noise power using the minimum statistics approach, which was originally proposed for audio processing. The proposed minimum statistics-based method separates a noisy image into multiple frequency bands using the three-level discrete wavelet transform. By assuming that the output of the high-pass filter contains both signal detail and noise, the proposed algorithm extracts the region of pure noise from the high frequency band using an appropriate threshold. The region of pure noise, which is free from the signal detail part and the DC component, is well suited for minimum statistics condition, where the noise power can be extracted easily. The proposed algorithm reduces the computational load significantly through the use of a simple processing architecture without iteration with an estimation accuracy greater than 90% for strong noise at 0 to 40dB SNR of the input image. Furthermore, the well restored image can be obtained using the estimated noise power information in parametric image restoration algorithms, such as the classical parametric Wiener or ForWaRD image restoration filters. The experimental results show that the proposed algorithm can estimate the noise power accurately, and is particularly suitable for fast, low-cost image restoration or enhancement applications.

• 감성과학
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• 제14권3호
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• pp.445-458
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• 2011

본 연구의 목표는 현대 기업경영의 핵심인 디자인리더십을 효과적으로 수행하기 위해서는 어떠한 요소들이 관리되어져야 하는지 또한 브랜드 중심의 디자인리더십을 위해 기업의 모든 부분들이 브랜드의 컨셉에 맞게 설정되어 있는지를 관리할 수 있는 요소와 그에 따른 실행방안들을 제안하는 것이다. 먼저 디자인리더십 관리의 요소로 크게 비전(Vision), 문화(Culture), 플랫폼(Platform)으로 나누고, 각 요소들을 관리하는데 있어 고려해야할 하위요소들을 설정하고 각 요소들에 대한 실행방안을 제시하였다. 다음으로 각 요소들의 실행방안을 인력구조, 브랜드침투 프로그램의 개발, 시간 및 물적 자원의 할당, 아이덴티티프로그램의 적용으로 유형화하였고 유형화한 범주에서 각각의 항목들을 설정하고 항목에 대한 세부 실행방안을 제안하였다. 이는 기업들이 디자인리더십을 실행함에 있어 요소들의 관리가 제대로 이루어지고 있는지에 대한 평가과정을 위한 가이드라인으로 활용될 수 있을 것이며 디자이너들이나 관리자들 컨설턴시들에게도 매우 유용한 지침이 될 수 있을 것으로 기대한다.

• 대한토목학회논문집
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• 제26권5B호
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• pp.439-446
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• 2006

본 연구에서는 강수량 및 기온과 같은 수문기상자료의 비선형 동역학적 성분을 추출하기 위해 웨이블렛 변환을 적용하여 대상자료를 재현기간별 성분으로 분리하였다. 변환을 위한 기저함수로는 Daubechies의 9번 ('db9') 웨이블렛 함수를 사용하였다. 또한 웨이블렛 변환의 스케일의 증가에 따른 각 분리단계에서 추출된 상세성분과 근사성분이 비선형 동역학적 특성을 지니는지를 판단하기 위하여 상관차원분석을 이용하였다. 즉 수문기상자료내에 비선형 동역학적 성질을 지니는 성분을 추출하기 위한 방법론으로써 웨이블렛 변환과 상관차원분석의 결합을 제안하였으며, 도출된 결과는 일반적으로 원자료를 이용할 경우에는 파악하기 어려운 대상자료의 시간에 따른 비선형적 변화를 분리 추출하기 위해 본 연구에서 제안한 방법이 적합함을 보이고 있다.

• Transactions on Electrical and Electronic Materials
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• 제15권5호
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• pp.257-261
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• 2014

Multilayered CdTe/PSS films were prepared by the electrostatic self-assembly method in an aqueous medium. Positively-charged cadmium telluride (CdTe) nanoparticles and anionic polyelectrolyte, poly (sodium 4-styrene sulfonate) (PSS) were assembled alternately in order to build up a multilayered film structure. A linear proportion of absorbance to the number of bilayers suggests that an equal amount of CdTe was adsorbed after each dipping cycle, which resulted in the buildup of a homogenous film. The binding energies of elements (Cd and Te) in multilayered CdTe/PSS film shifted from those of the CdTe nanoparticles in the pure state. This result indicates that the interfacial electron densities were redistributed by the strong electrostatic interaction between the oppositely-charged CdTe and PSS. Electrochemical properties of the multilayered CdTe/PSS films were studied in detail by cyclic voltammetry (CV).

• 한국측량학회:학술대회논문집
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• 한국측량학회 2002년도 창립 20주년기념 국제학술대회
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• pp.77-84
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• 2002

The Global Positioning System, GPS technology has been widely used in positioning and attitude determination. It is well known that the accuracy, availability and reliability of the positioning results are heavily dependent on the number and geometric distribution of tracked GPS satellites. Because of this limitation, in some situations, such as in urban canyons, underground space or inside of buildings, it is really hard to navigate with GPS receiver. Therefore, in order to improve the performance of satellite-based positioning, the integration of GPS with the pseudolite technology has been proposed. With this pseudolite technology, it is expected that seamless positioning service can be provided in wider area without replacing existing GPS receivers. On the other hand, to adopt pseudolites at larger scale, it is necessary to verify how the pseudolites can complement the existing GPS-based positioning. In this paper the authors present the detail of experimental investigations and the results of the fundamental verification for seamless positioning using integration of GPS and pseudolite. This paper shows that the accuracy and efficiency of integrating GPS and pseudolite through the dynamic and static positioning experiment and discuss about the influence on GPS receiver by pseudolite signal. The experimental results indicate that the accuracy of the height component can indeed be significantly improved, to approximately the same level as the horizontal component.

• 한국지구과학회지
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• 제24권5호
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• pp.402-410
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• 2003

이매패류 화석의 미구조를 박편상에서 관찰하면 시대가 오래된 것일수록 방해석의 재결정작용으로 인하여 성장선이 대부분 지워지는 반면 시대가 젊거나 현생의 이매패류는 매우 세밀한 성장선 및 구조가 그대로 보존된다. 패각이속성작용을 겪으면서 각피성분이 없어지고 외부에 노출되어 패각의 구성 물질인 Ca$^{2+}$이 주위 퇴적물에 존재하던 Fe$^{2+}$, Mg$^{2+}$, Mn$^{2+}$ 등과 치환되면서 색깔이 검게 된다. 이 과정에서 화석에서는 Ca함량이 낮아지는 대신 다른 금속의 함량이 높아진다. 자외선 및 가시광선 분광 분석 결과 반사도는 백악기 화석에서 현저히 낮고 제3기 화석 및 현생에서 비교적 높게 나타나며, 이는 주요 금속이온의 치환에 영향을 받는다는 사실을 알 수 있다.

• 한국전자거래학회지
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• 제7권1호
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• pp.129-140
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• 2002

To succeed in ERP construction, the purpose of ERP setup must be completed. To accomplish this end, it is required to analysis business process completely and make a plan in detail. For ERP providers', they must support a characterized ERP construction methodology and lower the construction cost by improving an ERP package by making it easy to customize. But, because imported EHP products that are supplied currently are designed for the standard and the rationality, they have a limit to support custom processes of domestic companies. On the contrary, ERP products by domestic companies are unable to support a consistent methodology of constructing ERP system. This is a main reason why much time and costs are consumed than that of an original plan. For solving the problems, ERP packages should provide a consistent process modeling methodology and a modeling tool which can support this methodology. Furthermore, customizing cost must be lowered by implementing reusable components from the process models. This Paper describes a component-based ERP Package system which has peculiar modeling tools and development tools. We describe the modeling methodology and the business component definition of the ERP system. Finally, we describe its customizing process based on these process designs and business components.

• 한국임상약학회지
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• 제26권2호
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• pp.181-186
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• 2016

Background: There has been on increasing emphasis on the importance of monitoring the safety of participants in a clinical trial to protect patients and maintain the integrity of the trial. The independent data monitoring committee (IDMC) has become common component of randomized clinical trials in recent years. Methods: It is important to consider the implications of different approaches that are being used in various countries. IDMC guidelines in Korea, US, and Europe were reviewed and compared to provide the objective, composition and operation of IDMC in detail. Results: IDMC is a group of experts in related subject are as who perform interim data monitoring to make a recommendation to the sponsor or organizer regarding appropriateness of trial continuation and the need for modifications of the trial. Independence of IDMC is preferred in order to minimize influence of factors unrelated to scientific, medical and ethical considerations that should underlie decision-making. Conclusion: IDMC has become an increasingly important component of clinical trials in recent years. Practical operating procedures need to be developed considering the future regulatory status of data monitoring committees.

• 한국생산제조학회지
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• 제24권3호
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• pp.348-354
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• 2015

Using a magnetic gear, the speed and torque of the driving axis can be decreased and increased, respectively, similar to a mechanical speed reducer. In particular, because the driving side can be isolated mechanically from the load side, the magnetic gear was developed for application with environmental constraints. Of the existing topologies used for the magnet gear, the filtering method of a specified magnetic component is the most competitive. In this paper, a novel unified harmonic modulator is applied to filter the specified component. The torque conversion method using this modulator is described in detail, and the key factors of the modulator are derived from the influence on the resulting torque. The experimental setup was constructed and its torque transmission efficiency measured for varying loads. The transient characteristic from an excessive load is compared with the theoretical simulation.