• 천문학회보
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• 제41권2호
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• pp.52.1-52.1
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• 2016

The Gamma-Ray Bursts (GRBs) are classified into the long GRBs (LGRBs) and the short GRBs (SGRBs). Their progenitors are expected to be different because they have its own distinct characteristics. Occasionally, the SGRBs having faint extended emission (EGRBs) are observed. The EGRBs exhibit the analogous properties that the SGRBs have, but observed T90 of the EGRBs is longer than two seconds as the LGRBs. Because the EGRBs have characteristics of the LGRBs and the SGRBs, study of the EGRBs is important to understand origins of the GRBs. In this study, we obtain the luminosity relations of the EGRBs observed by Swift/BAT. We compare these results with luminosity relations on the LGRBs and SGRBs. In addition, we examine the spectral lag relations of spike and extended emission component of the EGRBs detected by CGRO/BATSE, Konus/WIND, Swift/BAT, Fermi/GBM and compare to each other. We find that the luminosity relations of the EGRBs present different results with the LGRBs and the SGRBs. In the spectral lag relations, extended emission component expresses opposite results compared with spike component. Furthermore, the spectral lag relations from the four instruments came up with different outcomes to each other.

• KIEAE Journal
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• 제17권4호
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• pp.75-81
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• 2017

Purpose: Most contemporary office buildings supply external views, a sense of openness and a sense of time to their occupants by adopting the curtain walls, which are equipped with an outer cover having large window area. As a result, the amount of radiation increases, adversely affecting cooling load during the summer in office buildings. Although solar radiation decreases heating load and reduces energy costs during the winter period, due to the characteristics of offices where occupants work largely during daytime, the cooling load is important compared to the heating. Therefore, diverse measures to resolve those trade-offs and annual energy cost have been investigated. Method: In this study, the annual thermal load was comparatively analyzed according to the slat angle of the venetian blind along with lighting control technique. Result: After selecting effective conditions, in order to resolve such issues, this study established automated control strategies of slat angle depending on the window-to-wall ratio and zone orientation, so that the findings of this study can be effectively generalized to other circumstances.

• Journal of Forest and Environmental Science
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• 제32권1호
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• pp.99-102
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• 2016

Echolocation call structure and intensity were measured from the Malaysian Myotis muricola, which were recorded from the hand-released bat. The Malaysian M. muricola produced typical FM call pattern of the genus Myotis, producing steep, downward frequency-modulated calls. The average PF of calls is $64.39{\pm}1.33(kHz)$. Discrete PF patterns of two types are found, which consist of 63.39 kHz and 66.15 kHz. The averages of SF and D are $126.07{\pm}3.37kHz$ and $2.14{\pm}0.29ms$, respectively. There are various IPI lengths with average of $42.97{\pm}12.68ms$. A pulse consists of two harmonies which consist of the first harmony with wider bandwidth and the second harmony with narrower bandwidth. The PF of the first harmony is higher than that of the second harmony. The typical FM call structure, with two harmonies and wide bandwidth, would be highly related to fast flying and wide screening in the dense forests.

• Journal of Forest and Environmental Science
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• 제32권4호
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• pp.377-383
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• 2016

We obtained a total of 36 GPS coordinates of the seven bat species of Rhinolophus ferrumequinum, Myotis ikonnikovi, M. nattereri, M. petax, Murina ussuriensis, Plecotus auritus, and Pipistrellus abramus. Characteristics of forests (forest type, age class, DBH class and crown density), terrain (aspect, slope and distance from mountain stream) and disturbance factors (distance from human residential areas and distance from cultivated areas) that bats have used as their habitats were revealed from the GIS analysis based on GPS coordinates of the 36 positions that bats were found. The bats-preferred forest type is broad-leaf forests (43%) with the trees of the 2th (31%) and 5th (31%) age class, the trees of sapling (36%) and large DBH class (31%), and sparse crown density (67%). Bats prefer the slop direction of the east (39%), the gradient below $15^{\circ}$ (61%), the ranges within 200 m from the mountain streams (92%), the ranges within 200 m near roads (89%), the ranges of 200-400 m from human residential areas (28%), and the ranges within 200 m from cultivated areas (36%).

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권3호
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• pp.1348-1375
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• 2018

Support Vector Machine (SVM) is a well-known machine learning classification algorithm, which has been widely applied to many data mining problems, with good accuracy. However, SVM classification speed decreases with increase in dataset size. Some applications, like video surveillance and intrusion detection, requires a classifier to be trained very quickly, and on large datasets. Hence, this paper introduces two filter-based instance selection techniques for optimizing SVM training speed. Fast classification is often achieved at the expense of classification accuracy, and some applications, such as phishing and spam email classifiers, are very sensitive to slight drop in classification accuracy. Hence, this paper also introduces two wrapper-based instance selection techniques for improving SVM predictive accuracy and training speed. The wrapper and filter based techniques are inspired by Cuckoo Search Algorithm and Bat Algorithm. The proposed techniques are validated on three popular e-fraud types: credit card fraud, spam email and phishing email. In addition, the proposed techniques are validated on 20 other datasets provided by UCI data repository. Moreover, statistical analysis is performed and experimental results reveals that the filter-based and wrapper-based techniques significantly improved SVM classification speed. Also, results reveal that the wrapper-based techniques improved SVM predictive accuracy in most cases.

• KIEAE Journal
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• 제17권3호
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• pp.99-106
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• 2017

Purpose: Most modern office buildings adopt the curtain wall system in order to provide occupants with the sense of openness and high-technology, which requires large window area. As a result, the amount of solar radiation increases, negatively affecting cooling load during the summer and increasing energy costs. However, the performance of window itself is not sufficiently controllable parameter to control thermal comfort and solar radiation. Therefore, a shading device such as venetian blind is required to control them and thus a variety of studies have been performed thus far. So, the purpose of this study is to improve the performance of blind through the development of blind control algorithm. Method: Among various input variables for the control of venetian blinds, the vertical solar radiation has been selected in this study as the primary input variable and the optimal control algorithm for venetian blinds were developed for each window orientation. Result: The developed optimal control algorithm has a positive effect on building energy savings.

• 한국농림기상학회지
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• 제1권2호
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• pp.135-141
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• 1999

지표대기 모형 BATS를 한반도 사례에 적용하여 한반도 전지역에 대한 농업기상정보를 산출하였다. 자료입력에서 출력까지의 전 과정이 일괄적으로 수행될 수 있도록 모형의 입출력 및 전후처리 과정을 수정하였으며 이를 토대로 간단한 조작만으로 쉽게 농업기상요소들을 생산해 낼 수 있는 농업기상정보 자동산출시스템을 개발하였다. 모형의 결과와 관측값을 비교해 본 결과 지면온도와 뿌리대층 온도는 약 2.0$^{\circ}$C, 윗토양층 온도는 약 2.6$^{\circ}$C의 오차를 보이는 것으로 나타났다.

• 한국동물학회지
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• 제32권4호
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• pp.374-392
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• 1989

한국산 박쥐류의 계통분류학적 연구의 첫 단계로써, 1985년 10월부터 1987년 7월까지 18장소에서 채집된 한국산 박쥐류 중, 관박쥐과(Rhinolophidae)의 1종과 애기박쥐과 (Vespertilionidae)의 6종에 대하여 외·내부형태 및 상환골의 형태를 이용하여 분류학적인 검토를 하였다. 이들 중에는, 희귀종인 문둥이 박쥐(Eptesicus serotinus brachydigitus)가 포함되어, 본 아종에 대한 상세한 형태학적인 특징을 추가·기재하였다. 또한 현생 한국산 익수류상, 고기후 및 고지리를 고려하여 한국산 소익수류상의 성립과정에 대하여 고찰하였다. 즉, 홍적세의 고기후 및 고지리의 변화에 의해서, 남방계보다 북방계 종류가 풍부한 현재의 익수류상이 성립되었다고 생각된다. As a part of studies on taxonomy and phylogeny of bats inhabiting Korea, a taxonomic review of one rhinolophid and six vespertilionid bats collected at 18 localities during the period from October 1985 to July 1987 was carried out, basing on the external, cranial, dental and humeral morphology. These bats include a rare species, Eptesicus serotinus brachydigitus, the detailed characters of which were described in addition to the original description by Mori (1928b). Further, the Korean microchiropteran faunal succession was described laking into consideration the recent chiropteran fauna, and climatic and geographical changes in the Pleistocene: the recent bat fauna of Korea has become abundant in the north-originating species rather than in the south-originating ones, which is a reverse tendency in the Palearctic continent.

• Structural Engineering and Mechanics
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• 제56권3호
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• pp.385-407
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• 2015

This paper deals with the problem of the global stabilization for a class of tension leg platform (TLP) nonlinear control systems. It is well known that, in general, the global asymptotic stability of the TLP subsystems does not imply the global asymptotic stability of the composite closed-loop system. Finding system parameters for stabilizing the control system is also an issue need to be concerned. In this paper, we give additional sufficient conditions for the global stabilization of a TLP nonlinear system. In particular, we consider a class of NN based Takagi-Sugeno (TS) fuzzy TLP systems. Using the so-called parallel distributed compensation (PDC) controller, we prove that this class of systems can be globally asymptotically stable. The proper design of system parameters are found by a swarm intelligence algorithm called Evolved Bat Algorithm (EBA). An illustrative example is given to show the applicability of the main result.

• Journal of Electrical Engineering and Technology
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• 제9권4호
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• pp.1240-1247
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• 2014

The applications of Distributed Generation (DG) in a smart distribution grid environment are widely employed especially for power balancing and supporting demand responses. Using these applications can have both positive and negative impacts on the distribution system. The sizing and location of their installations are the issues that should be taken into consideration to gain the maximum benefit from them when considering the economic aspects. This paper presents an application of the Bat Algorithm (BA) for the optimal sizing and siting of DG in a smart distribution power system in order to maximize the Benefit to Cost Ratio (BCR), subjected to system constraints including real and reactive power generation, line and transformer loading, voltage profile, energy losses, fault level as well as DG operating limits. To demonstrate the effectiveness of the proposed methodology and the impact of considering economic issues on DG placement, a simplify 9-bus radial distribution system of the Provincial Electricity Authority of Thailand (PEA) is selected for the computer simulation to explore the benefit of the optimal DG placement and the performance of the proposed approach.