• 산업경영시스템학회지
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• 제43권2호
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• pp.25-32
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• 2020

Data on patent and scientific paper is considered as a useful information source for analyzing technological information and has been widely utilized. Technology big data is analyzed in various ways to identify the latest technological trends and predict future promising technologies. Clustering is one of the ways to discover new features by creating groups from technology big data. Patent includes refined bibliographic information such as patent classification code whereas scientific paper does not have appropriate bibliographic information for clustering. This research proposes a new approach for clustering data of scientific paper by utilizing reference titles in each scientific paper. In this approach, the reference titles are considered as textual information because each reference consists of the title of the paper that represents the core content of the paper. We collected the scientific paper data, extracted the title of the reference, and conducted clustering by measuring the text-based similarity. The results from the proposed approach are compared with the results using existing methodologies that one is the approach utilizing textual information from titles and abstracts and the other one is a citation-based approach. The suggested approach in this paper shows statistically significant difference compared to the existing approaches and it shows better clustering performance. The proposed approach will be considered as a useful method for clustering scientific papers.

• The Journal of Advanced Prosthodontics
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• 제14권6호
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• pp.369-378
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• 2022

PURPOSE. The purpose of this in vitro study was to assess whether scanning strategies of virtual interocclusal record (VIR) affect the accuracy of VIR during intraoral scanning. MATERIALS AND METHODS. Five pairs of reference cubes were added to the digital upper and lower dentitions of a volunteer, which were printed into resin casts. Subsequently, the resin casts were articulated in the maximal intercuspal position in a mechanical articulator and scanned with an industrial computed tomography system, of which the VIR was served as a reference VIR. The investigated VIR of the upper and lower jaws of the resin master cast were recorded with an intraoral scanner according to 9 designed scanning strategies. Then, the deviation between the investigated VIRs and reference VIR were analyzed, which were measured by the deviation of the distances of six selected reference points on the upper reference cubes in each digital cast to the XY-plane between the investigated VIRs and reference VIR. RESULTS. For the deviation in the right posterior dentitions, RP group (only scanning of right posterior dentitions) showed the smallest deviation. Besides, BP group (scanning of bilateral posterior dentitions) showed the smallest deviation in the left posterior dentitions. Moreover, LP group (scanning of left posterior dentitions) showed the smallest deviation in the anterior dentitions. For the deviation of full dental arches, BP group showed the smallest deviation. CONCLUSION. Different scanning strategies of VIR can influence the accuracy of alignment of virtual dental casts. Appropriate scanning strategies of VIR should be selected for different regions of interest and edentulous situations.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1211-1215
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• 2003

Accurate mathematical models of spacecraft components are an essential of spacecraft attitude control system design, analysis and simulation. Gyro is one of the most important spacecraft components used for attitude propagation and control. Gyro errors may seriously degrade the accuracy of the calculated spacecraft angular rate and of attitude estimates due to inherent drift and bias errors. In order to validate this model, nominal case simulation has been performed and compared for the low range mode and high range mode, respectively. In this paper, a mathematical model of gyro containing the relationships for predicting spacecraft angular rate and disturbances is proposed.

• 한국환경보건학회지
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• 제29권1호
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• pp.67-73
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• 2003

This study was carried out to characterize the behavior and sources of particulate trace metal in Daegu city. TSP (Total Suspended Particulate matter) was collected by filters on High Volume Air Sampler from the four areal (reference, residential, commercial, industrial area). The moult were analyzed by AAS after preliminary treatment. The average centration trend of trace metals contained in TSP was shown as follows : Fe > Cu > Pb > Mn > Ni > Cr > Cd. The trace metals showed the highest concentration in the industrial area. This study showed the seasonal variation of trace metals. Fe and Mn showed high concentration in spring, whereas Cr, Ni, Cd and Pb showed high concentration in winter. Also this study showed the regional variation of trace metals. The order of the average concentration of trace metals was : industrial > commercial > residential > reference area. Using Mn as a reference element, the enrichment factor analysis were used for identifying the trace element contributors. The enrichment factors of Cr, Fe < 10 were considered to have a significant dust and soil source and termed nonenriched. Pb, Cd, Cu >>10 were enriched and had a significant fraction which was contributed by anthropogenic sources.

• 대한전기학회논문지
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• 제33권8호
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• pp.289-298
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• 1984

The single phase induction motor is recently requested to meet a broad speed control and smooth forward and reverse operation due to the multifarious usages. This paper deals with two phase operation of a two winding motor by reference current adaptive inverter which can supply the currents to satisfy the balanced oeration into the main and auxiliary winding through the entire operational region. According to the roposed system, the starting, forward and reverse and variable speed control of a two winding motor eliminated the capacitor from the capacitor-run motor is also possible. The formation and its principle of the reference current adaptive inverter and characteristic analysis of the motor fed by this apparatus are described in this paper. Excellent agreement with the measured results and calculated values by computer simulation is obtained.

• 대한전기학회논문지:시스템및제어부문D
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• 제49권12호
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• pp.659-666
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• 2000

A stereo matching has been an important tool for reconstructing three dimensional terrain. By using stereo matching technique, DEM(Digital Elevaton Map) can be generated by the disparity from a reference image to a target image. Generally disparity map can be evaluated by matching the reference image to the target image and if the role of the reference and the target are interchanged, a different DEM can be obtained. In this paper, we propose a new fusion technique to estimate the optimal DEM by eliminating the false DEM due to occlusion. To detect the false DEM, we utilize two measure of accuracy: self-consistency and cross-correlation score. We test the effectiveness of the proposed methods with a quantitative analysis using simulated images. Experimental result indicate that the proposed methods show 24.4% and 33.1% improvement over either DEM.

• 한국도서관정보학회지
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• 제33권3호
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• pp.87-108
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• 2002

본 연구의 목적은 인터넷을 통해 접근하고 입수가능한 전자정보원을 대상으로 참고문헌 작성기준에 관한 스타일 메뉴얼들의 기술요소와 기재순서, 기술형식을 비교분석하여, 국내 연구자나 학협회, 출판사 등이 참고문헌을 작성하거나 작성지침을 제시할 때 포함할 수 있는 기술요소 및 형식에 관한 자료를 제공하는데 있다. 이를 위하여 최근에 수정보완된 MLA Style, APA Style, CBE Style, Chicago Style, ISO 690-2, SIST-02를 대상으로 그들의 요소와 순서, 표기방법 및 형식을 검토하고, 표기방법 및 형식에 따른 동일자료에 대한 기술사례를 제시하였다.

• 전기학회논문지
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• 제65권9호
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• pp.1590-1596
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• 2016

In this paper, catenary wires were analyzed aging through the experiment about a new product and a test sample in accordance with temperature changes from long-term use. In case of the contact wire, the maximum load was reduced within 7% and the tensile strength showed a reduced within 6.7% compared with a new reference standard $110mm^2$. 19 Strands of messenger wire have a little more than a standard value, but result data on tensile test were less than the reference value about stranded wire. Also parts among 49 strands of dropper was found to be smaller than the reference value and it appeared greatly increasing intensity as toward the center of the strand.

• Journal of Mechanical Science and Technology
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• 제16권6호
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• pp.745-756
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• 2002

The re-entry problem consists of guidance design and trajectory control. This paper summarizes the detailed relationships between the velocity, drag acceleration and altitude in determining reference trajectories. The computational issues are also addressed, and the performance of the proposed simple nonlinear control of a bank angle for the longitudinal/ lateral trajectory is demonstrated. In particular, the fixed bank angle methods that can reduce the drag acceleration errors at low-speeds are proposed. The importance of bank reversals with respect to the azimuth errors Is also elucidated.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2000년도 추계종합학술대회
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• pp.562-567
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• 2000

본 논문에서는 센서리스 벡터제어를 위한 MRAC를 이용해 속도추정기를 설계한다. 이 속도추정기는 파라미터 변동에 강인하며, 그 속도값은 센서리스 벡터제어구현을 위해 필요한 속도정보로 피드백되어 사용된다. 컴퓨터시뮬레이션을 통해 그 타당성을 입증하였다.