• 대한본초학회지
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• 제26권1호
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• pp.1-6
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• 2011

Objectives : Due to morphological similarity, many substitutes and counterfeits have been used as Moktong for thousands of years. This study was designed to determine discriminative criteria for identifying medicinal herbs used as Moktong. Methods : Akebia quinata, A. trifoliata, Clematis armandii, and Aristolochia manshuriensis were collected in various regions. Samples were authenticated and examined by observation and microscopy with paraffin embedding and triple staining using the modified Ju staining method. Results : Three different types of features to establish discriminative criteria for four kinds of Moktong were identified. Botanical features include differences in phyllotaxy, leaf shape, and caulescent. External morphological features were arrangement and size of fine holes(xylem), and overall shape of the section. Internal morphological features include the number of medullary rays, shape of the pitch, type of tissues rounding pitch, appearance of annual rings, shape and amount of crystals(calcium-oxalate), and the appearance of cork cambium. Further details(e.g. identification keys) are in the article. Conclusions : These criteria could provide an effective method for identifying numerous kinds of Moktong distributed in markets throughout northeast Asian nations.

• 정보과학회 논문지
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• 제43권8호
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• pp.848-856
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• 2016

해상 안전을 위한 선박의 탐색 및 식별은 매우 중요하다. 선박의 탐색은 레이더로 가능하나, 식별은 선박자동식별장치, 통신장비, 시각 등에 의해 이루어지며, 이러한 식별수단이 불능 시 레이더 운용자의 경험과 지식을 바탕으로 선박의 기동특성을 참고하여 식별하는 매우 어려운 경우가 발생한다. 본 논문에서는 지속적인 관찰임무를 수행해야 할 선박 탐색요원의 임무를 보조하기 위하여 레이더 상 선박의 기동특성을 이용, 자동식별 및 사고발생 가능성을 탐지하는 방법을 제안한다. 4가지 유형의 선박 정보, 레이더 상 접촉거리 및 침로, 속력을 이용하여 그 특징을 추출하고, SVM을 활용하여 식별 정확도를 평가하였으며, 이를 이용한 자동식별 알고리즘을 통해 사고발생 가능성이 있는 선박을 선별하는 방법을 제시하였다. 실험 결과 90% 이상의 식별 정확도를 보였으며, 실제 사고선박인 세월호의 정보를 자동식별 알고리즘에 적용하여 선별 가능함을 보였다. 이 방법은 다양한 상황에서 선박 탐색요원의 경험과 지식을 효과적으로 보완하고, 다수의 선박 중 관심필요선박을 사전 식별하여 정보를 제공함으로서 탐색요원의 노력을 경감시키고, 문제점을 보다 빨리 인지하는데 도움이 될 것이다.

• 전자공학회논문지
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• 제51권7호
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• pp.209-220
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• 2014

본 논문에서는 천해 배경잡음 환경에서 과도신호 분류에 적합한 특징 선택을 위해 특징의 변별력을 분석하였다. 과도신호 분류는 해양환경 특성상 낮은 신호대잡음비(SNR)를 가지므로 잡음변화에 강인한 특징이 요구된다. 천해 배경잡음을 모델링하기 위해 이론적인 잡음 모델과 Wenz의 천해 관측 자료 그리고 Yule walker 필터를 이용하였다. 과도신호의 SNR에 따른 각 특징의 변별력은 Fisher score를 이용하여 분석하였다. 변별력이 높은 특징을 선택하여 24 클래스의 과도신호원에 대한 분류정확도를 분석한 결과 잡음이 없는 환경에서 선택된 특징에서 상대적으로 높은 분류정확도를 보였다. 이러한 결과를 토대로 최종적으로 선택된 특징은 전체 28가지 특징 중 16가지 특징이 선택되었다. 다중 클래스 SVM분류기를 이용하여 선택된 특징의 인식률 분석결과 과도신호의 SNR 20dB 환경에서 약92%의 분류정확도를 보였다.

• 한국초등과학교육학회지:초등과학교육
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• 제37권2호
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• pp.173-187
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• 2018

The purpose of this study is to clarify the specific terms of epistemic and epistemological by reviewing the literature on epistemological understanding of science learning, examine the necessity of epistemic discourse analysis based on the view of social epistemology, and provide an exemplar of practical epistemology analysis for elementary children's science learning. The review was conducted in terms of meaning and terminology about epistemic or epistemological approach to science learning, epistemology of/for science, and methodologies for epistemic discourse analysis. As an alternative way of epistemic discourse analysis in science classroom I employed practical epistemology analysis (by Wickman), evidence-explanation continuum (by Duschl), and DREEC diagram (by Maeng et al.). The methods were administered to an elementary science class for the third grade where children observed sedimentary rocks. Through the outcomes of analysis I sought to understand the processes how children collected data by observation, identified evidence, and constructed explanations about rocks. During the process of practical epistemology analysis the cases of four categories, such as encounter, stand-fast, gap, and relation, were identified. The sequence of encounter, stand fast, gap, and relation showed how children observed sedimentary rocks and how they came to learn the difference among the rocks. The epistemic features of children's observation discourse, although different from scientists' discourses during their own practices, showed data-only conversation, evidence-driven conversation, or explanation inducing conversation. Thus I argue even elementary children are able to construct their own knowledge and their epistemic practices are productive.

• 천문학회지
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• 제36권spc1호
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• pp.109-115
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• 2003

We report the results of the ionospheric measurement obtained from the instruments on board the Korea Multi-Purpose Satellite - 1 (KOMPSAT-l). We observed a deep electron density trough in the nighttime equatorial ionosphere during the great magnetic storm on 15 July 2000. We attribute the phenomena to the up-lifted F-layer caused by the enhanced eastward electric field, while the spacecraft passed underneath the layer. We also present the results of our statistical study on the equatorial plasma bubble formation. We confirm the previous results regarding its seasonal and longitudinal dependence. In addition, we obtain new statistical results of the bubble temperature variations. The whole data set of measurement for more than a year is compared with the International Reference Ionosphere (IRI). It is seen that the features of the electron density and temperature along the magnetic equator are more prominent in the KOMPSAT-l observations than in the IRI model.

• 수산해양기술연구
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• 제35권3호
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• pp.291-300
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• 1999

In order to investigate the oceanic condition of fishing ground in the southwestern coastal sea of Korea, the oceanographic observation were carried out by the trainingship of Yosu university on May, August and November in 1998. Main features in the observation are as follows; 1) the ranges of temperature, salinity, density and chlorophyll-a were from $14.5^{\circ}C\;to\;18.0^{\circ}C,\; from\;33.5\textperthousand\;to\;34.5\textperthousand$from 24.0 to 25.5 and from $1.0\mu$g/l in spring (May) from $15.0^{\circ}C\;to\;27.5^{\circ}C,\;from\;0.0\textperthousand\;35.0\textperthousand$9.0 to 26.0 and from 0.5$\mu\textrm{g}$/l to 4.0$\mu\textrm{g}$/l in summer(August), and from $ to 21.0^{\circ}\;31.0\textperthousand$, from 22.0 and from $4.0\mug/l\;to\;20.0\mug/l$ in autumn(November), respectively, 2) the temperature in the coastal region was higher than that in the open ocean while salinity, density and chlorophyll-a were lower, and the convection was identified between the surface and the bottom during in spring and autumn, 3) the chlorophyll-a in the this region was varied in each season, being highly distributed offshore Yosu Bay, 4) on evidence of sea water intrusion toward Kumun island was observed.

• 로봇학회논문지
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• 제7권2호
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• pp.120-128
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• 2012

The loop closure problem is one of the most challenging issues in the vision-based simultaneous localization and mapping community. It requires the robot to recognize a previously visited place from current camera measurements. While the loop closure often relies on visual bag-of-words based on point features in the previous works, however, in this paper we propose a line-based method to solve the loop closure in the corridor environments. We used both the floor line and the anchored vanishing point as the loop closing feature, and a two-step loop closure algorithm was devised to detect a known place and perform the global pose correction. We propose an anchored vanishing point as a novel loop closure feature, as it includes position information and represents the vanishing points in bi-direction. In our system, the accumulated heading error is reduced using an observation of a previously registered anchored vanishing points firstly, and the observation of known floor lines allows for further pose correction. Experimental results show that our method is very efficient in a structured indoor environment as a suitable loop closure solution.

• Applied Microscopy
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• 제29권4호
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• pp.493-498
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• 1999

기억저장매체로서 광디스크의 개발이 활발히 진행되고 있으며 최근의 레이저 기술의 발전, 제조기술의 발전에 따른 기억밀도의 증가로서 기존의 자기기록매체와 경쟁을 하고 있다. 기록밀도의 증대와 신뢰성의 향상을 위하여 다층박막 구조를 가지는 광디스크의 미세구조는 더욱 복잡하며 소형화되고 있다. 이종의 물질로 구성된 다층박막형 광디스크의 미세구조 관찰 및 분석을 위해서는 투과전자현미경과 같은 미소영역 분석법이 필수적이며 비교적 간단하고 신뢰성 높은 시편준비법의 확립이 선행되어야 한다. 본 연구에서는 투과전자현미경 분석을 위한 광디스크의 평면 및 단면시료 제작법을 제시하고 제조된 시편으로부터 얻어진 광디스크의 미세구조 분석결과를 보고한다.

• 천문학회보
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• 제36권2호
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• pp.155.2-155.2
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• 2011

We present development of the calibration system for IGRINS (the Immersion GRating Infrared Spectrograph). We mainly use Th-Ar and U hollow cathode lamp as the spectral calibration source and telluric features can be used additionally. For the flat source, we selected a 3000K tungsten halogen lamp with 2 inch integrating sphere. From Light Tools simulation, the result flat image through calibration optics satisfied <1% flatness error requirement. We also present mechanical design of calibration box that will be attached on the IGRINS dewar. Three moving stages are designed to perform switching mechanism between all of the observing modes - target observation, flat, precision RV measurement, and spectro-polarimetric observation.

• 한국환경과학회지
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• 제24권4호
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• pp.481-494
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• 2015

Groundwater level hydrographs from observation wells in Jeju island clearly illustrate distinctive features of recharge showing the time-delaying and dispersive process, mainly affected by the thickness and hydrogeologic properties of the unsaturated zone. Most groundwater flow models have limitations on delineating temporal variation of recharge, although it is a major component of the groundwater flow system. Recently, a convolution model was suggested as a mathematical technique to generate time series of recharge that incorporated the time-delaying and dispersive process. A groundwater flow model was developed to simulate transient groundwater level fluctuations in Pyoseon area of Jeju island. The model used the convolution technique to simulate temporal variations of groundwater levels. By making a series of trial-and-error adjustments, transient model calibration was conducted for various input parameters of both the groundwater flow model and the convolution model. The calibrated model could simulate water level fluctuations closely coinciding with measurements from 8 observation wells in the model area. Consequently, it is expected that, in transient groundwater flow models, the convolution technique can be effectively used to generate a time series of recharge.