• Parasites, Hosts and Diseases
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• 제54권4호
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• pp.477-484
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• 2016

There is renewed interest in natural products as a starting point for discovery of drugs for schistosomiasis. Recent studies have shown that phytol reveals interesting in vivo and in vitro antischistosomal properties against Schistosoma mansoni adult worms. Here, we report the in vitro antischistosomal activity of phytol against Schistosoma haematobium juvenile and adult worms and alterations on the tegumental surface of the worms by means of scanning electron microscopy. The assay, which was carried out with 6 concentrations (25, 50, 75, 100, 125, and $150{\mu}g/ml$) of phytol, has shown a promising activity in a dose and time-dependent manner. There was a significant decline in the motility of the worms and a mortality rate of 100% was found at 48 hr after they had been exposed to phytol in the concentration of $150{\mu}g/ml$. Male worms were more susceptible. On the ultrastructural level, phytol also induced tegumental peeling, disintegration of tubercles and spines in addition to morphological disfiguring of the oral and ventral suckers. This report provides the first evidence that phytol is able to kill S. haematobium of different ages, and emphasizes that it is a promising natural product that could be used for development of a new schistosomicidal agent.

• 천문학회보
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• 제35권1호
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• pp.29.2-29.2
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• 2010

The Extreme ultraviolet Imaging Spectrometer (EIS) on board Hinode provide us with excellent imaging spectroscopic data with very good spatial and spectral resolutions, which can be used for detecting Doppler flows in transition region and coronal lines as well as diagnosing plasma properties such as temperature, density, and non-thermal velocity. In this study we have made an EUV-imaging spectroscopic study of the source region of a partial halo coronal mass ejection (CME) that occurred on 2007 July 9 in NOAA 10961. Dopplergrams are obtained before and after the CME eruption using 12 EIS spectral lines (Log T= 4.9~7.2). Major results are summarized as follows. First, it is noted that either red shifts disappeared or blue shifts newly appeared for all spectral lines lower than Log T =6.0. Second, there were significant intensity increases for all wavelengths. Third, there were no significant variations in non-thermal motions for all wavelengths. We found one interesting bright point that newly appeared after the CME eruption. We discuss the implication on the results in terms of the CME eruption.

• 한국경제지리학회지
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• 제2권1_2호
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• pp.123-144
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• 1999

본 연구는 통합여수시를 사례로 도시생활환경의 측정 및 삶의 질 변화에 대한 도시민의 인식.평가의 변화를 설문조사를 통해 살펴보았고, 이를 바탕으로 지역주민의 삶의 질을 향상시킬 수 있는 정책적 대안을 제시하였다. 통합여수시의 삶의 질은 5년 전에 비해서 전체적으로 삶의 질은 향상된 것으로 분석되었다. 그러나 삶의 질에 관한 9개 지표 중에서 주거생활, 도시행정 및 편익서비스 등은 5년전보다 상대적으로 향상된 반면, 자연환경, 문화 및 여가생활, 교통환경 등은 나빠진 것으로 평가하였다. 그리고 여수시민들은 통합여수시의 지속적인 발전을 도모하기 위해서는 교통문제, 문화 및 여가시설의 확충 등이 주요한 과제라고 인식하였고, 21세기의 통합여수시가 해양관광도시, 교육문화도시로 발전하기를 선호하였다. 따라서 여수대도시권을 구축율 위한 주요 과제로는 경제기반시설의 확충, 워터프런트의 개발 및 보전, 관광산업의 활성화, 시민중심의 도시경관 조성, 지역문화운동의 전개 등이 필요한 것으로 밝혀졌다.

• 한국게임학회 논문지
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• 제9권6호
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• pp.31-44
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• 2009

Brain-Computer Interface(이하 BCI)는 뇌파를 활용하여 인간의 의지로 컴퓨터를 제어하는 수단이나 행위이다. 뇌파 인터페이스 관련 하드웨어 제작 기술이 발전함에 따라 고가이면서 대형이었던 뇌파 측정 장비가 최근에는 소형화 되고 개인이 구매 가능한 가격대로 출시되면서 앞으로 다양한 멀티미디어 분야에서 응용이 될 것으로 예상된다. 이 논문은 뇌파 인터페이스 장치를 게임의 새로운 장치로 활용이 가능한지에 대해 게임 디자인적 관점에서 접근한다. 먼저 논문에서는 뇌파 인터페이스 장치를 적극적으로 활용할 수 있는 게임 플레이 요소를 제안하고 체계화하며, 이를 기반으로 하는 게임의 시제품을 제작하였다. 다음으로 기존의 키보드, 마우스를 입력 장치로 사용하는 게임과의 비교 체험을 통해 뇌파 인터페이스 장치의 활용이 직관적이고 효율적인 게임 플레이를 제공하는지에 대해 통계적인 분석을 하였으며, 실제로 직관성과 흥미로움을 제공한다는 사실이 검증되었다. 본 논문의 결과는 BCI 기반 게임 제작을 위한 효과적인 게임 디자인 가이드라인이 될 것으로 판단된다.

• 한국항행학회논문지
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• 제16권2호
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• pp.394-400
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• 2012

SURF(Speeded Up Robust Features)는 다양한 상태 변화에 강인한 기술자 추출 방법으로 객체 인식과 같은 분야에서 유용하게 사용되는 알고리즘이다. 이 알고리즘은 대표적인 특징점 추출 알고리즘인 SIFT(Scale Invariant Feature Transform)와 비슷한 성능을 보이면서도 수행 시간이 훨씬 빠르다는 장점이 있다. 하지만 이러한 기술자들은 회전 불변한 특징 보장을 위해서, 추출한 특징점 간의 위치 정보를 고려하지 않는다. 또한, 원본 영상을 흑백 영상으로 변환하여 사용하기 때문에, 원본 이미지의 색상 정보도 이용하지 않는다. 본 논문에서는 특징점들 간의 상대적인 위치 정보 및 색상 정보를 이용하여 SURF 기술자의 정합 성능을 개선하는 방안을 제안한다. 상대적인 위치 정보는 특징점들의 중심을 연결하는 선분과 특징점 중심에서부터 생성되는 orientation 선분 사이의 각을 기반으로 한다. 색상 정보의 경우 각 특징점이 포함하고 있는 영역에 대해 color histogram을 생성하여 사용한다. 실험을 통하여 제안된 기법의 성능 개선을 보인다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.425.1-425.1
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• 2014

Thermal transport in nanomaterials is not only scientifically interesting but also technological important for various future electronic, bio, and energy device applications. Among the various computation approaches to investigate lattice thermal transport phenomena in nanoscale, the atomistic nonequilibrium Green's function approach based on first-principles density functional theory calculations appeared as a promising method given the continued miniaturization of devices and the difficulty of developing classical force constants for novel nanoscale interfaces. Among the nanometerials, carbon atomic chains, namely the cumulene (all-doulble bonds, ${\cdots}C=C=C=C{\cdots}$) and polyyne (alternation of single and triple bonds, ${\cdots}C{\equiv}C-C{\equiv}C{\cdots}$) can be considered as the extream cases of interconnction materials for nanodevices. After the discovery and realization of carbon atomic chains, their electronic transport properties have been widely studied. For the thermal transport properties, however, there have been few literatures for this simple linear chain system. In this work, we first report on the development of a non-equilibrium Green's function theory-based computational tool for atomistic thermal transport calculations of nanojunctions. Using the developed tool, we investigated phonon dispersion and transmission properties of polyethylene (${\cdots}CH2-CH2-CH2-CH2{\cdots}$) and polyene (${\cdots}CH-CH-CH-CH{\cdots}$) structures as well as the cumulene and polyyne. The resulting phonon dispersion from polyethylene and polyene showed agreement with previous results. Compared to the cumulene, the gap was found near the ${\Gamma}$ point of the phonon dispersion of polyyne as the prediction of Peierls distortion, and this feature was reflected in the phonon transmission of polyyne. We also investigated the range of interatomic force interactions with increase in the size of the simulation system to check the convergence criteria. Compared to polyethylene and polyene, polyyne and cumulene showed spatially long-ranged force interactions. This is reflected on the differences in phonon transport caused by the delicate differences in electronic structure.

• 음성과학
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• 제11권2호
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• pp.71-87
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• 2004

Korean has a pair of voiceless fricatives, whose laryngeal manifestation comes in parallel to stops and affricates with a three-way lexical contrast. Prior phonetic studies by Kagaya (1974), Iverson (1983), and Kang (1999, 2000) point out /s/ is associated with multiple characteristics of the larynx shared with not only the lax but also the aspirated series, whereas /s' / carries a laryngeal distinction typical of the tense consonants. The complex dual nature of /s/ is again supported by a psycholinguistic study by Kang (2004), as /s/ was found to interact with /$c^h$/ (17% of the time) as well as /c/ (57%) in speech errors. In addition, a recent work by Cho and Lee (2003) notes an interesting chain shift case in the acquisition of the fricatives. Although they observed a significant phonological pattern between child English and Korean, Cho and Lee's description of acquiring fricatives is far from being precise from the perspective of phonetics. From a longitudinal study of recorded tapes by two children at 1;7-3;8 and 1;7-2;1 respectively, I found that /s' / was usually substituted into tense noncontinuants in young children's early production as predicted, whereas /s/ having both lax and aspirated-like glottal properties revealed a complicated pattern of substitutions into lax, tense, and aspirated noncontinuants with a varying degree of preference relative to the subjects. The current acquisition study supports the previous claims concerning fricatives in other languages, showing that their acquisition comes after stops. Besides, it also notes that Korean fricatives are subject to a series of phonological processes called stopping, affricating, tensifying and palatalizing during the transitional period of phonological development by young children. Moreover, between the two voiceless types, /s/ was acquired earlier than /s'/ as the unmarked segment.

• Journal of Animal Science and Technology
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• 제60권5호
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• pp.12.1-12.5
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• 2018

Background: The use of agroindustrial by-products in ruminant nutrition to be an interesting alternative in order to reduce production costs and environmental impacts arising from the inadequate destination of residues. The initial step of beer production yields a large volume of wet brewer's grains all year around, which is available at a low cost and has a high nutritional quality, and hence a big potential for animal production. Methods: Twenty-four Suffolk non-castrated male lambs, from simple parturition were kept in individual spots and allocated to four treatments constituted by four levels of substitution of sorghum silage by WBG (i.e.0; 33.5; 66.5 and 100% of substitution). It was used roughage: concentrate rate of 50:50, based on dry matter. Results: The ether extract intake increased while the acid detergent fiber intake decreased linearly ($P{\leq}0.05$). Substituion of sorghum silage by WBG did not change lambs' feed DMI, daily weight gain and feed conversion. Conclusion: The substitution of sorghum silage by WBG as roughage showed to be a viable alternative from the productive and economic point of view for finishing of feedlot lambs.

• 대한수학교육학회지:수학교육학연구
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• 제21권4호
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• pp.313-326
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• 2011

본 연구에서는 PISA수학성취도 자료와 국내외 성차 관련 연구 자료를 분석하여 우리나라 학생들의 성차 추이와 그에 대한 배경을 살펴보았다. 우리나라는 2000년과 2003년 PISA수학성취도 평가에서 유의미하게 큰 성차를 보인 반면 2006년부터 성차가 급격히 감소하였다. 이러한 성차의 급격한 감소 현상에 영향을 미친 요인을 탐색하기 위해 국내외 성차 관련 연구 자료를 분석하였으며, 이를 토대로 여성의 이공계 진출을 유도하는 국가차원의 정책적 지원과 같은 사회문화적 변화와 교육과정과 그에 따른 교과서의 변화 등과 같은 요인들이 여학생의 수학 성취도 향상에 긍정적인 영향을 미쳤을 것으로 판단된다.

• 한국측량학회지
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• 제32권3호
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• pp.245-251
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• 2014

As delineating market areas of retail businesses has become an interesting topic in marketing field, Lee and Lee recently suggested a noteworthy method, which applied the hydrological analysis of geographical information system (GIS), based on Christaller's central place theory. They used a digital elevation model (DEM) which inverted the kernel density of retail businesses, which was measured by using bandwidths of pre-determined 500, 1000 and 5000 m, respectively. In fact, their method is not a fully data-based approach in that they used pre-determined kernel bandwidths, however, this paper has been planned to improve Lee and Lee's method by using a kind of data-based approach of the L-index that describes clustering level of point feature distribution. The case study is implemented to automobile-related retail businesses in Seoul, Korea with selected Kernel bandwidths, 1211.5, 2120.2 and 7067.2 m from L-index analysis. Subsequently, the kernel density is measured, the density DEM is created by inverting it, and boundaries of market areas are extracted. Following the study, analysis results are summarized as follows. Firstly, the L-index can be a useful tool to complement the Lee and Lee's market area analysis method. At next, the kernel bandwidths, pre-determined by Lee and Lee, cannot be uniformly applied to all kinds of retail businesses. Lastly, the L-index method can be useful for analyzing the space structure of market areas of retail businesses, based on Christaller's central place theory.