• Journal of Positioning, Navigation, and Timing
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• 제11권4호
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• pp.369-379
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• 2022

In weighted k-nearest neighbor (WkNN)-based Fingerprinting positioning step, a process of comparing the requested positioning signal with signal information for each reference point stored in the fingerprint DB is performed. At this time, the higher the number of matched base station identifiers, the higher the possibility that the terminal exists in the corresponding location, and in fact, an additional weight is added to the location in proportion to the number of matching base stations. On the other hand, if the matching number of base stations is small, the selected candidate reference point has high dependence on the similarity value of the signal. But one problem arises here. The positioning signal can be compared with the repeater signal in the signal information stored on the DB, and the corresponding reference point can be selected as a candidate location. The selected reference point is likely to be an outlier, and if a certain weight is applied to the corresponding location, the error of the estimated location information increases. In order to solve this problem, this paper proposes a WkNN technique including an outlier removal function. To this end, it is first determined whether the repeater signal is included in the DB information of the matched base station. If the reference point for the repeater signal is selected as the candidate position, the reference position corresponding to the outlier is removed based on the clustering technique. The performance of the proposed technique is verified through data acquired in Seocho 1 and 2 dongs in Seoul.

• 복식문화연구
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• 제5권1호
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• pp.151-164
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• 1997

This study pursues the problems of plan photogrammetry which is widely used in somatotyping at present, and find out a method which can improve accuracy of measurement on the basis of principles and mechanisms of photography-the basic foundation of the photographic analysis methods. As a result, this study proposes a new method which is based on the reference point method and perspective coordinate system. And the test measurement was operated to compare the measurement accuracy of the proposed method and the method based on reference grid screen method and perpendicular coordinate system which is commonly used at present. The result of this test measurement showed that the proposed method has higher accuracy. Two reasons can be pointed out for the improvement of measuring accuracy. The first reason is that the proposed perspective coordinate system reduces the perspective distortion of photography. And second reason is that measuring points can be closely placed to the scale and coordinate reference plan of measurement by the proposed reference point method which make possible to place measuring object (or person) at the center of scale and coordinate reference plan by utilizing reference points of measurement in the three dimensional space not on screen.

• Journal of Mechanical Science and Technology
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• 제17권1호
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• pp.77-84
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• 2003

Virtual work in multibody systems is frequently expressed as the inner product of the virtual displacement and the resultant force at the centroid. But provided that the resultant force is converted into the equipollent forces there is no restriction on where the analysis reference point is placed. There are basically three candidate points : the centroid, joint point and the instant global origin. The traditional fully recursive formulation uses the centroid, but the present work verifies that the instant global origin always shows better efficiency (e.g. 86% CPU time of the centroid for quarter car model) and joint point shows the efficiency between that of the centroid and the instant global origin. A discussion on how important it is to define the analysis reference point properly in a fully recursive formulation is also presented.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 춘계학술대회
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• pp.421-424
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• 2022

허프변환은 에지 영상에서 직선을 검출하는 대표적인 알고리즘이다. 허프변환은 에지 화소에서 발생 가능한 직선들의 파라미터들을 파라미터 공간상에 대응시키고, 주어진 조건을 만족하는 유효 파라미터를 직선으로 검출한다. 일반적인 허프변환에서는 직선의 파라미터들은 영상 원점을 기준점으로 계산되고 있다. 그러나 본 논문에서는 영상 중심이 기준점인 허프변환을 수행하고 그 성능을 기존 허프변환과 비교분석하고 있다.

• 한국정밀공학회지
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• 제29권1호
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• pp.72-78
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• 2012

In this research an equilibrium point of a Wheeled Inverted Pendulum (WIP) running on an inclined road is derived and validated by some experiments. Generally, The WIP has stable and unstable equilibrium point. Only unstable equilibrium point is interested in the research. To keep the WIP on the unstable equilibrium point, the WIP is consistently controlled. A controller for the WIP needs a reference state for the equilibrium point. The reference state can be obtained by studying an equilibrium point of the WIP. This research is deriving dynamic equations of the WIP running on the inclined road and equilibrium of it based on statics. Several experiments are carried out to show the validation of the equilibrium point.

• 대한의용생체공학회:의공학회지
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• 제44권5호
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• pp.346-353
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• 2023

In this paper, we propose an innovative approach that leverages deep learning to find optimal reference points for achieving precise tooth segmentation in three-dimensional tooth point cloud data. A dataset consisting of 350 aligned maxillary and mandibular cloud data was used as input, and both end coordinates of individual teeth were used as correct answers. A two-dimensional image was created by projecting the rendered point cloud data along the Z-axis, where an image of individual teeth was created using an object detection algorithm. The proposed algorithm is designed by adding various modules to the Unet model that allow effective learning of a narrow range, and detects both end points of the tooth using the generated tooth image. In the evaluation using DSC, Euclid distance, and MAE as indicators, we achieved superior performance compared to other Unet-based models. In future research, we will develop an algorithm to find the reference point of the point cloud by back-projecting the reference point detected in the image in three dimensions, and based on this, we will develop an algorithm to divide the teeth individually in the point cloud through image processing techniques.

• 경영정보학연구
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• 제17권2호
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• pp.219-238
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• 2015

인터넷과 정보기술의 발달로 사람들은 많은 정보에 접하게 되었으며, 정보 제공 사이트들은 사용자들에게 적합한 정보를 추천해 줌으로써 정보 과잉의 문제를 해결해 왔다. 하지만, 사용자의 취향과 선호에 기반한 정보 추천은 편향된 정보만을 소비하게 되는 정보 편식의 문제점을 일으킬 수 있다. 이러한 추천시스템의 부작용에 대해서는 연구가 거의 행해지지 않아 왔다. 본 논문은 정보 편식을 완화시키는 정보 시스템적 솔루션에 초점을 맞췄다. 적응수준이론과 기대이론을 기반으로 사용자 자신의 정보 소비 행태를 준거점으로 구체화시킨 자기 준거 진단 인터페이스와 타인들의 정보 소비 행태를 준거점으로 자신의 정보 소비를 보도록 도와주는 사회적 준거 진단 인터페이스를 제안하였다. 이러한 두 개의 인터페이스가 정보 소비 행태 자각에 어떤 영향을 미치며, 행동의 자각이 정보 편식을 개선하려는 동기와 실제 행동에 영향을 미치는지를 알아보았다. 인터페이스의 효과는 실험을 이용하여 검증하였다. 분석 결과, 자기 준거 진단 인터페이스가 정보 소비 행태 자각과 정보 편식을 개선하는 행동에 긍정적인 영향을 미치는 것으로 나타났지만, 정보 편식을 개선하고자 하는 동기에는 유의한 결과를 보이지 않았다. 본 연구는 사람들이 선호하는 정보를 제공하는 것에만 관심을 기울였던 기존 연구들과는 달리 추천 시스템의 부작용인 정보 편식의 완화에 관심을 가진 연구라는 의의를 가진다.

• 한국문헌정보학회지
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• 제45권1호
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• pp.11-27
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• 2011

본 연구는 협력형디지털정보봉사(CDRS: collaborative digital reference service)를 대상으로 그 사례를 분석하여 국내 CDRS의 향후 발전방안을 모색하려는 의도로 진행되었다. 전 세계적 범위의 협력적 봉사에 의해 정보봉사의 전문화를 모색하려는 CDRS의 해외 사례는 미국의 QuestionPoint를 비롯하여 7개국의 국가도서관이 주도하는 사례가 대상이 되며 국내의 사례는 국립중앙도서관의 "사서에게 물어보세요"가 그 대상이다. 중점적 분석에 의한 국내의 본 서비스는 이용자들로부터의 활용이 매년 증가되며 대학생과 직장인들의 연구 및 업무수행에 활동되는 등 향후의 전문봉사로서의 발전 가능성이 확인되고 있다.

• 한국멀티미디어학회논문지
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• 제20권1호
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• pp.74-81
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• 2017

In learning stage of the preliminary Cut-off indoor positioning scheme, RSSI and UUID data received from beacons at each reference point(RP) are stored in fingerprint map. The fingerprint map and real-time beacon information are compared to identify the nearest K reference points through which the user position is estimated. If the number of K is zero, this scheme cannot estimate user position. We have improved the preliminary Cut-off scheme to get the estimated user position even in the case. The improved scheme excludes the beacon of the weakest signal received by user mobile device and identifies neighborhood reference points using the other beacon information. This procedure are performed repetitively until K > 0. The simulation results confirm that the proposed scheme outperforms K-Nearest-Neighbor (KNN), Cluster KNN and the conventional Cut-off scheme in terms of accuracy while the constraints are guaranteed to be satisfied.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 추계학술발표회 논문집
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• pp.405-410
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• 2004

In mid-90's, the Korean government introduced the GIS(Geographic Information System) to digitalize every topography of national land and thereby, index locations and attributes of various urban facilities to construct a system whereby every information could be managed and operated in an integrated way, but the reliability of such geographic information has yet to be tested, much less its modification, complementation and maintenance. Under such circumstances, this study was aimed at constructing a reference point infrastructure for Seoul and Kyonggi area and comparing the data obtained from the GPS operation and various facility location data with the existing GIS data to address the problems of GIS operation and suggest their solutions. As a result of calculating the GPS reference point data and analyzing the deviations of the unknown point data in comparison with the fixed point ones, it was found that the horizontal location values were reliable within +/- 5cm, but that the above-sea level values varied as much as 1.4m depending on the deployment of pre-set fixed points determined by the direct level gauging. In addition, as a result of directly surveying major facilities around the roads based on the coordinates of the urban reference points networked with such a reference point system to check their conformity to existing data, it was confirmed that the difference was as wide as 2m. Such differences may be attributable to the fact that the data with their geographic information not confirmed are used as basic data for GIS. Hence, this study suggests the ways to set the absolute geographic data based on reference points and test the reliability of existing data and thereby, suggests a methods to solve the problems.