• Journal of the Institute of Electronics Engineers of Korea CI
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• v.43 no.4 s.310
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• pp.88-102
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• 2006

In multimedia information retrieval, multimedia data are represented as vectors in high dimensional space. To search these vectors effectively, a variety of indexing methods have been proposed. However, the performance of these indexing methods degrades dramatically with increasing dimensionality, which is known as the dimensionality curse. To resolve the dimensionality curse, dimensionality reduction methods have been proposed. They map feature vectors in high dimensional space into the ones in low dimensional space before indexing the data. This paper proposes a method for dimensionality reduction based on a function approximating the Euclidean distance, which makes use of the norm and angle components of a vector. First, we identify the causes of the errors in angle estimation for approximating the Euclidean distance, and discuss basic directions to reduce those errors. Then, we propose a novel method for dimensionality reduction that composes a set of subvectors from a feature vector and maintains only the norm and the estimated angle for every subvector. The selection of a good reference vector is important for accurate estimation of the angle component. We present criteria for being a good reference vector, and propose a method that chooses a good reference vector by using Levenberg-Marquardt algorithm. Also, we define a novel distance function, and formally prove that the distance function lower-bounds the Euclidean distance. This implies that our approach does not incur any false dismissals in reducing the dimensionality effectively. Finally, we verify the superiority of the proposed method via performance evaluation with extensive experiments.

• Journal of the Economic Geographical Society of Korea
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• v.13 no.3
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• pp.297-311
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• 2010

The purpose of this study is to analyze the causality among GRDP, patent, investment of R &D, and researcher among 16 Metropolitan cities and provinces in Korea. Using the annual data ranged from 1998 to 2008, the causality test for time-series data such as unit roots test and Granger causality test were performed. We estimate the Panel-Var of the four variables to find out the various Granger causal relations for two groups which are classified by the patent productivity. The panel data causality results reveal that there are bidirectional causality relations among four variables for the more patent-productivity group. The patent has bi-directional effects on GRDP and R&D. The patent cause GRDP and vice versa, patent cause R&D and vice versa. Patent not only has strong direct impact on GRDP and R&D but also has affected by the increase of GRDP and R&D through the interactive feedback mechanism. However, the causality patterns are somewhat different between the more patent-productive region and the less patent-productive region. There exists one directional causality between the R&D and GRDP for the less patent-productivity group. Such result may imply that the type of regional innovation policy should be differentiated between two groups. Regional economic policy efforts should be placed on increasing the knowledge productivity and on strengthening the regional competitiveness through the regional innovative infrastructure.

• Progress in Medical Physics
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• v.26 no.4
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• pp.241-249
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• 2015

As radiation therapy is one of three major cancer treatment methods, many cancer patients get radiation therapy. To exposure as much radiation to cancer while normal tissues near tumor get little radiation, medical physicists make a radiotherapy plan treatment and perform quality assurance before patient treatment. Despite these efforts, unintended medical accidents can occur by some errors. In order to solve the problem, patient internal dose reconstruction methods by measuring transit dose are suggested. As feasibility study for development of patient dose verification system, inverse square law, percentage depth dose and scatter factor are used to calculate dose in the water-equivalent homogeneous phantom. As a calibration results of ionization chamber and glass dosimeter to transit radiation, signals of glass dosimeter are 0.824 times at 6 MV and 0.736 times at 10 MV compared to dose measured by ionization chamber. Average scatter factor is 1.4 and Mayneord F factor was used to apply percentage depth dose data. When we verified the algorithm using the water-equivalent homogeneous phantom, maximum error was 1.65%.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.6
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• pp.201-211
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• 2013

In this paper, we propose a hand tracking and gesture recognition system. Our system employs a depth capture device to obtain 3D geometric information of user's bare hand. In particular, we build a flexible tracking volume and restrict the hand tracking area, so that we can avoid diverse problems caused by conventional object detection/tracking systems. The proposed system computes running average of the hand position, and tracking volume is actively adjusted according to the statistical information that is computed on the basis of uncertainty of the user's hand motion in the 3D space. Once the position of user's hand is obtained, then the system attempts to detect stretched fingers to recognize finger gesture of the user's hand. In order to test the proposed framework, we built a NUI system using the proposed technique, and verified that our system presents very stable performance even in the case that multiple objects exist simultaneously in the crowded environment, as well as in the situation that the scene is occluded temporarily. We also verified that our system ensures running speed of 24-30 frames per second throughout the experiments.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.10
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• pp.150-161
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• 2013

This paper presents a new system which produces high resolution 3D contents by capturing multiview images of an object using multiple cameras, and estimating geometric and texture information of the object from the captured images. Even though a variety of multiview image-based 3D reconstruction systems have been proposed, it was difficult to generate high resolution 3D contents because multiview image-based 3D reconstruction requires a large amount of memory and computation. In order to reduce computational complexity and memory size for 3D reconstruction, the proposed system predetermines the regions in input images where an object can exist to extract object boundaries fast. And for fast computation of a visual hull, the system represents silhouettes and 3D-2D projection/back-projection relations by chain codes and 1D homographies, respectively. The geometric data of the reconstructed object is compactly represented by a 3D segment-based data format which is called DoCube, and the 3D object is finally reconstructed after 3D mesh generation and texture mapping are performed. Experimental results show that the proposed system produces 3D object contents of $800{\times}800{\times}800$ resolution with a rate of 2.2 seconds per frame.

• Spatial Information Research
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• v.18 no.4
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• pp.1-11
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• 2010

Unlike the previous studies which have focused on 2-dimensional urban characteristics, this paper presents statistical models explaining urban heat island(UHI) effect by 3-dimensional urban morphologic information and addresses its policy implications. 3~dimensional informations of Columbus, Ohio arc captured from LiDAR data and building boundary informations are extracted from a building digital map, Finally NDV[ and temperature data are calculated by manipulating band 3, band 4, and thermal hand of LandSat images. Through complicated data processing, 6 independent variables(building surface area, building volume, height to width ratio, porosity, plan surface area) are introduced in simple and multiple linear regression models. The regression models are specified by Box-Tidwell method, finding the power to which the independent variable needs to raised to be in a linearity. Porosity, NDVI, and building surface area are carefully chosen as explanatory variables in the final multiple regression model, which explaining about 57% of the variability in temperatures. On reducing UHI, various implications of the results give guidelines to policy-making in open space, roof garden, and vertical garden management.

• Journal of the Earthquake Engineering Society of Korea
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• v.7 no.3
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• pp.69-77
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• 2003

This paper presents test results on eight reduced beam section(RBS) steel moment connections. The testing program addressed bolted versus welded web connection and panel zone(PZ) strength as key variables, Specimens with medium PZ strength were designed to promote energy dissipation from both PZ and RBS regions such that the requirement for expensive doublet plates could be reduced. Both strong and medium PZ specimens with a welded web connection were able to provide satisfactory connection rotation capacity for special moment-resisting frames. On the other hand, specimens with a bolted web connection performed poorly due to premature brittle fracture of the beam flange of the weld access hole. If fracture within the beam flange groove weld was avoided using quality welding, the fracture tended to move into the beam flange base metal of the weld access hole. Plausible explanation of a higher incidence of base metal fracture in bolted web specimens was presented. The measured strain data confirmed that the classical beam theory dose not provide reliable shear transfer prediction in the connection. The practice of providing web bolts uniformly along the beam depth was brought into question. Criteria for a balanced PZ strength improves the plastic rotation capacity while reduces the amount of beam distortion ore also proposed.

• The Korean Journal of Nuclear Medicine Technology
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• v.21 no.2
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• pp.28-30
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• 2017

Purpose Anti-Glutamic acid decarboxylase antibody test (GAD Ab) has been used as a predictor of type 1 diabetes. GAD Ab has also been shown to be highly potent in cerebrospinal fluid (CSF) of patients with suspected diabetic peripheral neuropathy. Recently, it has been known that clinical significance of GAD Ab using CSF is useful for the neurological disorders. However, the reference value of anti-GAD Ab has been provided only for serum. In this experiment, we estimated the reference value of anti-GAD antibody for CSF in neurological patients. Materials and Methods A total of 211 neurological patients were enrolled. Serum and CSF were analyzed by radioimmunoassay (RIA) using commercial RIA anti-GAD Ab kit (RSR, London, United Kingdom). Normal saline was used as the normal CSF control because CSF is most similar to 0.9% normal saline. Results The mean value of normal CSF control was 1.97 U/mL, and two standard deviations (2SD) was 1.44 U/mL. Based on this data, the expected reference range of CSF could be estimated from 0.54 U/mL to 3.40 U/mL Conclusion The reference range of normal CSF control using normal saline obtained with Hoffmann's method. However, there will be a need to validate the CSF reference values using human normal CSF.

• Proceedings of the Technology Innovation Conference
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• 2003.06a
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• pp.41-56
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• 2003

다양한 제품들이 존재하는 시장에는 타 제품에 비하여 품질대비 가격이 낮은 혁신적인 경쟁력있는 제품과 그렇지 못한 제품들이 혼재하고 있다. 그러나 정보의 부족(limited information), 제한적 합리성(bounded rationality) 등 여러 가지 원인으로 인하여 혁신적인 제품들만이 소비자들에게 선택되어 소비되는 것은 아니다. 본 연구에서는 이러한 현상을 설명하기 위하여 소비효율성(consumption efficiency)라는 개념을 도입, 제시하고자 한다. 만약 소비효율성이 극도로 낮다면 혁신적인 제품을 내어놓는다 하더라도 소비자들에게 선택되어 이윤이 발생될 확률이 낮기 때문에 생산자 입장에서는 혁신의 유인(innovation incentive)이 낮아질 수밖에 없게 된다. 이처럼 소비효율성의 문제는 혁신의 유인과 결과를 이해하는데 중요한 단초를 제공할 수 있게 된다. 이에 반하여 혁신을 이해하기 위한 기존의 분석틀은 생산경제이론(production economics)에 기반하고 있고, 효율성의 개념도 생산효율성(production efficiency) 혹은 기술적 효율성(technical efficiency)의 범주에서 다루어져 왔다. 본 연구에서 제시하는 소비효율성의 개념은 효용이론에 근거하고 있다는 점에서 기존 연구와 차별화된다. 본 연구는 효용함수 극대화이론에서 출발하여 경계헤도닉함수(frontier hedomic function)을 도출하는 이론적 유도과정을 제시한다. 실증분석을 위해서는 SFA(Stochastic Frontier Analysis)의 방법론 체계를 적용하였다. 제시된 분석틀은 국내 PC산업의 데이터에 적용되었다. 분석의 결과 몇 가지 가정하에 국내 PC산업이 약 13%정도의 비효율성을 안고 있는 것으로 판단할 수 있으며, 초기혁신구매자(early adopter)들은 일정 정도의 비효율성을 기꺼이 감수할 것으로 분석되었다. 궤적 분석에서는 각 산업별 기술의 특성을 분석하는 것으로, 특정 기술 지식의 활용 기간을 통해 기술 주기를 도출하고, 산업 내 평균 권리 청구 항목 수를 이용하여 각 산업의 기술 범위를 비교하였다. 각각의 동적 분석을 통해 시간에 따른 변화 양상이 관찰하였고, ANOVA 분석을 이용하여 통계적 유의성을 검증하였다. 본 연구는 현재의 기술 패러다임 내에서 Pavitt이 제시한 산업 분류의 근거를 보충 설명하였고 특허 정보를 이용하여 기술혁신의 산업별 유형에 대한 폭넓은 분석방법을 제시하였다.별 시간대별 효과분석을 통하여 정책의 시행여부가 결정되어야 할 것이다. 한편, 화물전용차선의 설치로 인한 물류비용의 절감을 보다 효과적으로 달성하기 위해서는 종합류류 전산망의 시급한 구축과 함께 화물차의 적재율을 높이고 공차율을 낮출 수 있는 운송체계의 수립이 필요한 것으로 판단된다. 그라나 이러한 화물전용차선의 효과는 단기적인 치유책일 수밖에 없기 때문에 물류유통 시설의 확충을 위한 사회간접자본의 구축을 서둘러 시행하여야 할 것이다.으로 처리한 Machine oil, Phenthoate EC 및 Trichlorfon WP는 비교적 약효가 낮았다.>$^{\circ}$E/$\leq$30$^{\circ}$NW 단열군이 연구지역 내에서 지하수 유동성이 가장 높은 단열군으로 추정된다. 이러한 사실은 3개 시추공을 대상으로 실시한 시추공 내 물리검층과 정압주입시험에서도 확인된다.. It was resulted from increase of weight of single cocoon. "Manta"2.5ppm produced 22.2kg of cocoon. It is equal to 9% increase in index, as compared to that of control. In case of R-20458, the increasing

• Journal of Science and Technology Studies
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• v.4 no.1 s.7
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• pp.1-30
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• 2004

In this paper, I have attempted to show how the environmental controversy surrounding the Saemangeurn Reclamation Project in Korea has been framed as narrow scientific debates. First of all, science, or specifically the Expert Review Pane, has played dual roles in the controversy. On the one hand, it has contributed to illuminating the future environmental impacts of reclamation, by so doing, to providing a momentum to reconsider the project. This has significant meaning that environmental concerns successfully checked the symbolic national project of developmental era through adopting a joint-investigation scheme that guaranteed participation of environmental groups on an equal footing with the government. On the other hand, by limiting the scope and participants of discussion, it fundamentally blocked the possibilities of public debates and deliberative decision-making with full considerations of the political, social, and cultural aspects of the controversy. I have shown that this is due to the realist belief shared by both the developers and the environmentalists in Korea that 'proper' science would disclose the truth. Environmental groups, in particular, were naive in evaluating the role of scientific expertise in the controversy and neglected the political role of the Expert Review Pane as a ritual. In opposition to the realist argument, I have shown through the analysis of the water quality debates concerning the future fresh water lakes that scientific 'facts' were not discovered but constructed through complex negotiations, conflicts, and compromises among related actors. The framing of the controversy as an experts' debate has resulted in the exclusion of an important actor from the discussion. Little attention has been paid throughout the controversy to the very people who have lived in the Saemangeum area for generations and will lose their livelihood all together soon. About 20,000 fishermen are living on the Saemangeum tidal flats.