• 한국수자원학회논문집
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• 제49권3호
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• pp.253-262
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• 2016

수위-유량 관계곡선(rating curve)은 수위표에서 관측된 수위 및 유량을 이용하여 만들어진 회귀분석식을 의미하며, 하천의 수위를 유량으로 환산하는 방법으로 일반적으로 활용되고 있다. 그러나 수위-유량 관계곡선식에서 저수위와 고수위와 분리 및 매개변수 추정에 있어 불확실성을 고려한 해석은 이루어지지 않고 있다. 이러한 이유로 본 연구에서는 수위-유량 관계곡선식에서 매개변수 추정 및 저 고수위 분리시 발생하는 문제점을 개선하기 위해 Bayesian 기법을 도입하였으며, 수위-유량 관계곡선식의 매개변수의 추정과 더불어 불확실성을 정량화 하는데 목적을 두었다. 이와 더불어 Bayesian 모형 기반 Multi-Segmented 수위-유량 관계곡선(Bayesian M-S)을 활용하여 저 고수위를 분리할 수 있는 새로운 수위-유량 관계곡선을 개발하고 기존 수위-유량 관계곡선과 비교 분석을 실시하였다. 그 결과 본 연구에서 개발한 Bayesian M-S 기법이 기존 수위-유량 관계곡선식 보다 개선된 결과를 도출할 수 있었으며, 수위-유량 관계곡선식의 신뢰구간을 제시하는데 유리한 것을 확인할 수 있었다.

• Nuclear Engineering and Technology
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• 제55권1호
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• pp.373-377
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• 2023

The Monte Carlo (MC) method has become an indispensable part of the nuclear radiation research field. Several widely used and well-known MC packages were developed for simulation of radiation transport and interaction with matter. All these MC packages require users to prepare an input script. The input script can become lengthy for complex models. The process of preparing these input scripts is time-consuming and error-prone. In the present work, we have developed an open-source GUI computer program for modelling radiation transport and interaction in multi-segmented slab phantoms using grid-based system for the widely used PHITS MC package. The developed tools would be useful for future users of PHITS MC package and particularly inexperienced users. The present program is distributed under GPL license and all users can freely download, modify and redistribute the program without any restrictions.

• 센서학회지
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• 제24권2호
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• pp.101-106
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• 2015

We designed, developed and characterized a multi-segmented tissue equivalent proportional (TEPC) counter for microdosimetry. The energy resolution of the multi-segmented TEPC was about 12% for $^{241}Am$ 5.45 MeV alpha particles. The resolution was better than 33% for a single un-segmented TEPC. A compact and low power consumption TEPC could be made by using digital pulse processor (DPP). We also successfully calibrated the TEPC by using $^{252}Cf$ standard neutron source in Korea Research Institute of Standards and Science (KRISS). According to the results, the TEPC is useful for several application of radiation monitoring such as a neutron monitor, air crew monitor and space dosimeter.

• 디지털산업정보학회논문지
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• 제9권3호
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• pp.13-20
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• 2013

In this paper, we propose a multi-scale crack detection method. This method uses decomposition, composition, and shape properties. It is based on morphology algorithm, crack features. We use a morphology operator which extracts patterns of crack. It segments cracks and background using opening and closing operations. Morphology based segmentation is better than existing integration methods using subtraction in detecting a crack it has small width. However, morphology methods using only one structure element could detect only fixed width crack. Thus, we use decomposition and composition methods. We use a decimation method for decomposition. After decomposition and morphology operation, we get edge images given by binary values. Our method calculates values of properties such as the number of pixels and the maximum length of the segmented region. We decide whether the segmented region belongs to cracks according to those data. Experimental results show that our proposed multi-scale crack detection method has better results than those of existing detection methods.

• Journal of Information Processing Systems
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• 제14권5호
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• pp.1293-1300
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• 2018

For the disadvantages of multi-scale geometric analysis methods such as loss of definition and complex selection of rules in image fusion, an improved multi-focus image fusion method is proposed. First, the initial fused image is quickly obtained based on the lifting stationary wavelet transform, and a simple normalized cut is performed on the initial fused image to obtain different segmented regions. Then, the original image is subjected to NSCT transformation and the absolute value of the high frequency component coefficient in each segmented region is calculated. At last, the region with the largest absolute value is selected as the postfusion region, and the fused multi-focus image is obtained by traversing each segment region. Numerical experiments show that the proposed algorithm can not only simplify the selection of fusion rules, but also overcome loss of definition and has validity.

• 한국경영과학회지
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• 제24권1호
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• pp.13-25
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• 1999

This paper presents a model of competitive positioning and pricing of new products in a multi-segmented market. The segments in the market are located on a multi-dimensional discrete attribute space with fixed demands. Firms launch products sequentially on the attribute space, incurring fixed and variable costs, and then decide on their product prices. Each firm acts to maximize its profit. Market share of a firm is determined by the position and price of Its product. We provide sufficient conditions for the existence and uniqueness of Nash equilibrium Another equilibrium concept is Introduced and related to the Nash equilibrium. A heuristic algorithm based on genetic algorithms is designed to obtain the Nash equilibrium.

• 대한전자공학회논문지SD
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• 제42권4호
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• pp.9-18
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• 2005

본 논문은 OCP(Open Core Protocol)에 호환되는 파이프라인 구조를 가진 시스템 버스와 MPEG 시스템에 적합한 메모리 버스로 구성된 계층 구조를 가지는 새로운 동기 세그먼트 버스를 제안한다. 이 구조는 MPEG 시스템의 모바일 제품에 사용되는 영상 데이터 처리를 위한 메모리 인터페이스에 기반을 둔 버스 구조와 멀티 마스터와 멀티 슬레이브를 사용하여 고성능의 다중 처리를 위한 양방향 다중 버스 구조(hi-direction multiple bus architecture)를 가진다. 효율적인 데이터 처리를 위하여 파이프라인 스테이지와 결합된 마스터와 슬레이브의 주소번지가 latency를 결정하며, 시스템의 특성에 따라서 각각의 IP 코어를 배치하였다. 제안된 버스는 저전력 구현을 위하여 세그먼트 버스 구조를 가지고, 멀티미디어 SoC 시스템의 성능 저하 없이 다중 작업이 가능한 구조를 가지며 확장이 가능하다. 제안된 버스 구조는 AMBA와 비교하였을 때 bandwidth는 3.7배 증가하였고 latency는 0.25배 감소하였다.

• Journal of Magnetics
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• 제17권2호
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• pp.100-108
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• 2012

Flux concentrated permanent magnet transverse flux machines, FCPM-TFMs, with segmented stators require multi-turn concentric saddle coils to replace the ring coils, which are normally utilized in conventional layeredphase TFM constructions. In this paper, we investigate the influence of the shape of saddle phase windings and their parameter variations on the output torque productivity. Non-meshed coils evaluated via a finite element method (FEM) to examine the effect of the coil's location within one phase on machine performance. By using meshed coils, the analysis can be extended to inspect the distributions of magnetic field strength as well as current density in the coils. Throughout the study, the influence of design parameters on the output torque for two stator structures, i.e., a laminated and soft magnetic composite (SMC), are evaluated.

• 한국정보통신학회논문지
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• 제8권5호
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• pp.1080-1088
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• 2004

본 논문은 조도, 형태, 배경의 변화에 강인한 다중 비디오카메라에서 색 정보를 이용한 보행자 추적에 대하여 제안한다. 제안된 방법은 비디오카메라로부터 입력되는 영상의 색조만을 이용하여 배경영상과 물체가 존재하는 영상에서 차영상 기법과 가산투영 기법을 사용하여 이동물체를 검출한다. 검출된 이동물체 영역의 색조는 0도부터 360도 사이에서 15도씩 24단계로 분할된다. 검출된 이동물체 영역의 색조 분포도를 구한 후, 가장 높은 분포를 갖는 3개의 색조 레벨과 3개의 색조 레벨 사이의 차를 이동물체의 특징파라미터로 사용하였다. 제안된 방법의 유용성을 증명하기 위하여 조도와 형태의 변화가 발생한 보행자 영상과 조도, 형태, 배경의 변화가 발생한 보행자 영상을 이용하여 보행자를 감시한 결과 카메라에서 검출된 특정사람의 색조 분포 레벨과 색조 레벨 사이의 차는 2레벨 이하로 유지함을 보였고, 제안된 특징 파라미터로 특정사람이 자동 추적감시 됨을 확인하였다.

• Smart Structures and Systems
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• 제14권2호
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• pp.247-266
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• 2014

Conventional cantilevered piezoelectric energy harvesters (PEHs) are usually fabricated with continuous electrode configuration (CEC), which suffers from the electrical cancellation at higher vibration modes. Though previous research pointed out that the segmented electrode configuration (SEC) can address this issue, a comprehensive evaluation of the PEH with SEC has yet been reported. With the consideration of delivering power to a common load, the AC outputs from all segmented electrode pairs should be rectified to DC outputs separately. In such case, theoretical formulation for power estimation becomes challenging. This paper proposes a method based on equivalent circuit model (ECM) and circuit simulation to evaluate the performance of the PEH with SEC. First, the parameters of the multi-mode ECM are identified from theoretical analysis. The ECM is then established in SPICE software and validated by the theoretical model and finite element method (FEM) with resistive loads. Subsequently, the optimal performances with SEC and CEC are compared considering the practical DC interface circuit. A comprehensive evaluation of the advantageous performance with SEC is provided for the first time. The results demonstrate the feasibility of using SEC as a simple and effective means to improve the performance of a cantilevered PEH at a higher mode.