• ETRI Journal
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• 제40권3호
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• pp.389-395
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• 2018

A novel class of planar metamaterial unit-cells consisting of a peace logo pattern is presented. A significant advantage of the proposed peace-logo planar metamaterial (PLPM) unit-cell over existing designs is its tunability, simplicity, and compatibility with microstrip structures. The theoretical analysis is founded on the famous transmission-line theory for the metamaterial concept. Then, the tunable dual-band two-sided PLPM (TSPLPM) unit-cell is designed by printing a similar PLPM pattern at the bottom of the substrate. The influence of the bottom PLPM pattern on the resonance frequencies of the unit-cell was analyzed by performing numerical simulations using CST Microwave Studio 2017 and HFSSv15 simulators. The results of the numerical simulations demonstrated that the proposed TSPLPM has the ability to control the resonance frequencies over 50 GHz-75 GHz for millimeter-wave applications.

• Journal of Power Electronics
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• 제15권6호
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• pp.1577-1583
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• 2015

In this research, a combined adaptive-robust current controller is developed for non-minimum-phase DC-DC converters in a wide range of operations. In the proposed nonlinear controller, load resistance, input voltage and zero interval of the inductor current are estimated using developed adaptation rules and knowing the operating mode of the converter for the closed-loop control is not required; hence, a single controller can be employed for a wide load and line changes in discontinuous and continuous conduction operations. Using the TMS320F2810 digital signal processor, the experimental response of the proposed controller is presented in different operating points of the buck/boost converter. During transition between different modes of the converter, the developed controller has a better dynamic response compared with previously reported adaptive nonlinear approach. Moreover, output voltage steady-state error is zero in different conditions.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 A
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• pp.66-68
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• 2000

The Eigen analysis in large power system provides much useful information that is not got in nose curve. The branch participation factor is not quantitative information and is an indirect method calculating incremental change in branch reactive loss. But the Eigen sensitivity analysis to each mode is direct and provides of quantitative information but this method because of needing much time is used in large power system. In this paper the Hessenberg method is used to obtaining dominant eignvalues and corresponding eigenvectors of Jacobian matrix. Ranking the critical contingencies is done by computing the Eigen sensitivity of each dominant eignvalues for changes of each line. The proposed algorithm is tested on the New England 30-bus system and KEPCO system in the year of 2000, which comprises of 791-bus and 2500-branches.

• 천문학회지
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• 제29권spc1호
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• pp.133-134
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• 1996

We present the systematic variations of H$\beta$ index of simple stellar populations due to horizontal-branch (HB) stars. Most of the previous works have been done without careful considerations of HB stars. Since the Balmer line strengths are very sensitive to the temperature, including the HB stars are quite important. We found that the strength of H,6 index is strongly affected by HB stars, and hence the age estimation without careful consideration of the variation of HB morphology with metallicity and age would underestimate the ages of ellipticals.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권9호
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• pp.2232-2245
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• 2013

The present study proposes efficient procedural modeling methods for enabling the growth and creation of various trees with minimal user control. Growth volume algorithms are utilized in order to easily and effectively calculate many parameters that determine tree growth, including branch propagation. Procedural methods are designed so that users' interactive control structures can be applied to these algorithms to create unique tree models efficiently. First, through a two-line-based interactive growth volume control method, the growth information that determines the overall shape of the tree is intuitively adjusted. Thereafter, independent branch control methods designed to control individual branches are added to the growth deformation in order to enable the growth of unique trees. Whether the growth processes of desired trees can be easily and intuitively controlled by the proposed method is verified through experiments. Methods that can apply the proposed methods are also verified.

• Food Science and Biotechnology
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• 제18권3호
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• pp.749-754
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• 2009

The polysaccharide (BB-pol) extracted from Bifidobacterium bifidum BGN4 showed growth inhibitory effects on several colon cancer cell lines such as HT-29 and HCT-116. To increase the yield of polysaccharide, B. bifidum BGN4 was cultured in various culture media with different compositions. When B. bifidum BGN4 was cultured in modified MRS broth containing phytic acid, the cells showed increased branch formation and enlarged morphology. The content of total carbohydrate and the ability of adhesion to intestinal epithelial cells were also increased by phytic acid. The polysaccharide obtained from the cells grown in the presence of phytic acid inhibited the proliferation of cancer cell lines such as HT-29 and MCF-7 cells but not normal colon cell line, FHC. Taken together, Bifidobacterium grown in the presence of phytic acid may confer enhanced beneficial function for the host.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 Asia Navigation Conference
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• pp.56-62
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• 2006

This thesis researches on the application of computer, modern communication, GIS, GPS, AIS and World-Wide-Web in the field of navigation-aids information system, and has realized an integrated system consisted of navigation-aids information GIS platform, navigation-aids monitoring system and navigation-aids information distribution system. This system has strong integration capability, and has realized navigation-aids information distribution based on WEBGIS at the first time. It strongly promotes navigation-aids daily management and maintenance, and this system provides technique guarantee fur ships and marine departments to acquire navigation-aids information in time, by rule and line expediently.

• 대한산업공학회지
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• 제24권3호
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• pp.417-429
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• 1998

This paper considers two-sided (left and right side) assembly lines which are often used, especially in assembling large-sized products such as trucks and buses. A large number of exact algorithms and heuristics have been proposed to balance one-sided lines. However, little attention has been paid to balancing two-sided assembly lines. We present an efficient algorithm based on a branch and bound for balancing two-sided assembly lines. The algorithm involves a procedure for generating an enumeration tree. To efficiently search for the near optimal solutions to the problem, assignment rules are used in the method. New and existing bound strategies and dominance rules are else employed. The proposed algorithm can find a near optimal solution by enumerating feasible solutions partially. Extensive computational experiments are carried out to make the performance comparison between the proposed algorithm and existing ones. The computational results show that our algorithm is promising and robust in solution quality.

• 한국멀티미디어학회논문지
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• 제7권4호
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• pp.459-466
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• 2004

골격선 추출에 대한 향상된 디지털 이미지를 획득하기 위해서 효과적인 골격화 방법을 제안한다. 제안한 방법은 임계값을 이용한 이진화를 거친 후에 본 방법을 적용하여 영상 골격화 효율을 높이고자 한다. 기존의 골격화 방법은 Rutovits, Stefabelli 그리고 그 외에 5가지 방법을 사용하였다. 기존의 방법은 많은 부분에서 팽창과 잡음가지들이 생성되어 골격화를 이루는데 어려운 점이 많았다. 그러나 제안된 방법은 수정된 병렬처리 단계를 통해서 먼저 문제점들을 제거하였고, 첨가하여 제안된 8가지 제거 조건들에 일치하면 중앙 화소를 제거하여 골격화 품질을 향상시켰다.

• 수산해양기술연구
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• 제49권3호
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• pp.227-237
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• 2013

In Jeju Island, red sea bream is mainly caught by long line with a live squid as bait. The movements of artificial jigs in the fishery are supposed to be an important factor for catching the target organism as well as bait. To develop new fishing method for long line fishery, movements of the bait which was squid were tried to be characterized. In a water tank experiment, a live squid was hooked by a fish hook attached to a model long line. And then movements of squids in the water tank were recorded for 20 minutes by a video camera. Recorded movement of the squid was just periodically up-and-down moving, with a dominant frequency of 0.125Hz, and amplitude of 10.8cm.