• Title/Summary/Keyword: intersection index

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A Study on the Optimization of IoU (IoU의 최적화에 관한 연구)

  • Xu, Xin
    • Proceedings of the Korea Information Processing Society Conference
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    • 2020.05a
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    • pp.595-598
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    • 2020
  • IoU (Intersection over Union) is the most commonly used index in target detection. The core requirement of target detection is what is in the image and where. Based on these two problems, classification training and positional regression training are needed. However, in the process of position regression, the most commonly used method is to obtain the IoU of the predicted bounding box and ground-truth bounding box. Calculating bounding box regression losses should take into account three important geometric measures, namely the overlap area, the distance, and the aspect ratio. Although GIoU (Generalized Intersection over Union) improves the calculation function of image overlap degree, it still can't represent the distance and aspect ratio of the graph well. As a result of technological progress, Bounding-Box is no longer represented by coordinates x,y,w and h of four positions. Therefore, the IoU can be further optimized with the center point and aspect ratio of Bounding-Box.

Theory and practice of alphabetical subject indexing (주제색인의 이론과 실제)

  • 윤구호
    • Journal of Korean Library and Information Science Society
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    • v.10
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    • pp.95-131
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    • 1983
  • Index is a systematic guide to items contained in, or concepts derived from, a collection, Thus, it is represented as a paired set of index terms (t) and documents (D) : I= {(t,D) vertical bar t .mem. V, D .mem. W), where V is index vocabulary and W is document collection. Indexing is the process of analysing the informational content of records of knowledge and expressing the informational content in the language of the indexing system. It involves: 1) Selecting indexable concepts in a document; and 2) expressing these concepts in the language of the indexing system (as index entries): and an ordered list. Indexing process involves technical, semantic and syntactic problems. Technical problems are related to the accuracy of indexing, which is primarily governed by the indexer's ability of analysing subject, identifying indexable concepts, and coding. The proper levels of indexing exhaustivity, and index language specificity are also significant factors affecting the quality of index. Semantic problems are related to the choice of index terms and the form in which they should be used. Equivalent, hierarchical and affinitive/associative relationships of index terms are involved. Syntactic problems are largely related to the coordination of index terms. This process of coordination arises from the need to be able to search for the intersection of two or more classes defined by terms denoting distinct concepts. Finally, most valuable aspects of alphabetical subject indexing theories and practices are derived from those of Cutter, Kaiser, Ranganathan, Coates, Lynch and Austin, and discussed in details.

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Robust GPU-based intersection algorithm for a large triangle set (GPU를 이용한 대량 삼각형 교차 알고리즘)

  • Kyung, Min-Ho;Kwak, Jong-Geun;Choi, Jung-Ju
    • Journal of the Korea Computer Graphics Society
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    • v.17 no.3
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    • pp.9-19
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    • 2011
  • Computing triangle-triangle intersections has been a fundamental task required for many 3D geometric problems. We propose a novel robust GPU algorithm to efficiently compute intersections in a large triangle set. The algorithm has three stages:k-d tree construction, triangle pair generation, and exact intersection computation. All three stages are executed on GPU except, for unsafe triangle pairs. Unsafe triangle pairs are robustly handled by CLP(controlled linear perturbation) on a CPU thread. They are identified by floating-point filtering while exact intersection is computed on GPU. Many triangles crossing a split plane are duplicated in k-d tree construction, which form a lot of redundant triangle pairs later. To eliminate them efficiently, we use a split index which can determine redundancy of a pair by a simple bitwise operation. We applied the proposed algorithm to computing 3D Minkowski sum boundaries to verify its efficiency and robustness.

Grasp Stability Analysis in Dual-Space and Optimal Grasp Planning for Two-Fingered Robots in 2-D (듀얼 공간을 이용한 이차원 두 손가락 로봇의 파지 안정성 분석 및 최적 파지 계획)

  • Kook, Myung-Ho;Jang, Myeong-Eon;Lee, Ji-Hong
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.11
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    • pp.1102-1110
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    • 2006
  • This paper addresses the problem of computing grasp stability of the object for two-fingered robots in two dimensions. The concepts of force-closure and dual space are introduced and discussed in novel point of view, and we transform friction cones in a robot work space to line segments in a dual space. We newly define a grasp stability index by calculating intersection condition between line segments in dual space. Moreover, we propose a method to find the optimal grasp points of the given object by comparing the defined grasp stability index. Its validity and effectiveness are investigated and verified by simulations for quadrangle object and elliptic objects.

THE NILPOTENCY OF THE PRIME RADICAL OF A GOLDIE MODULE

  • John A., Beachy;Mauricio, Medina-Barcenas
    • Bulletin of the Korean Mathematical Society
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    • v.60 no.1
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    • pp.185-201
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    • 2023
  • With the notion of prime submodule defined by F. Raggi et al. we prove that the intersection of all prime submodules of a Goldie module M is a nilpotent submodule provided that M is retractable and M(Λ)-projective for every index set Λ. This extends the well known fact that in a left Goldie ring the prime radical is nilpotent.

Evaluation of Performance Index of Dual-arm manipulator for Multiple Shape Object Handling (Multiple Shape Object Handling을 위한 양팔로봇의 성능지수 평가)

  • Son, Joon-Bae;Chen, Hu;Lee, Jang-Myung
    • The Journal of Korea Robotics Society
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    • v.7 no.1
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    • pp.9-19
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    • 2012
  • This paper proposes a performance index for the multiple shape object handling of dual arm manipulator to determine whether a robot is good or not. When the dual-arm manipulator grasps a fixed object and is posed, the dual-arm manipulator should procure a space to freely control the manipulator. As a performance evaluation parameter, each joint torque from current sensor signal is utilized. From the current information, torque and energy for each joint are estimated. In this paper an performance index for an unstructured object is defined by an energy-cost function, and stability analysis for each motion is derived by the maximum force to the object. The maximum force to the object is computed by the inertia of object and acceleration information of end-effector. The acceleration data are derived by the double derivation of each encoder signal. Manipulability measure which implies how efficiently the dual-arm manipulator can move with the grasped object, can be represented by the intersection of the two manipulability ellipsoids for the left and right arms. Effectiveness of the proposed algorithm has been verified through the practical simulations and real experiments.

Feasibility Evaluation of Lane Grouping Methods for Signalized Intersection Performance Index Analysis in KHCM (도로용량편람 신호교차로 성능지표 분석을 위한 차로군 분류의 적정성 평가)

  • Kim, Sang-Gu;Yun, Ilsoo;Oh, Young-Tae;Ahn, Hyun-Kyung;Kwon, Ken-An;Hong, Doo-Pyo
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.13 no.1
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    • pp.109-126
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    • 2014
  • The level of service (LOS) of the Highway Capacity Manual (KHCM) has been used as a basic criterion at decision making processes for signalized intersections in Korea. The KHCM provides five steps for the signalized intersection analysis. Among them, lane grouping, which is the third step, significantly influence the final LOS. The current method presented in the KHCM, however, classifies a shared lane as a de facto turning lane group, even though the turning traffic of the shared lane is few. Thus, this research was initiated to provide an alternative. To this end, three alternatives were suggested, including the method based on the lane grouping presented in the U.S. Highway Capacity Manual, the method using turning ratio of shared turning lane, and the method using a threshold traffic volume in lane grouping. The feasibilities of the three methods were evaluated using a calibrated CORSIM model. Conclusively, the method using a threshold traffic volume in lane grouping outperformed.

Development of Accident Modification Factors for Road Design Safety Evaluation Algorithm of Rural Intersections (지방부 교차로의 도로설계 안전성 판단 알고리즘 구축을 위한 AMF 개발 (신호교차로를 중심으로))

  • Kim, Eung-Cheol;Lee, Dong-Min;Choe, Eun-Jin;Kim, Do-Hun
    • Journal of Korean Society of Transportation
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    • v.27 no.3
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    • pp.91-102
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    • 2009
  • A traffic accident prediction model developed using various design variables(road design variables, geometric variables, and traffic environmental variables) is one of the most important factors to safety design evaluation system for roads. However, statistical accident models have a crucial problem not applicable for all intersections. To make up this problem, this study developed AMFs(Accident Modification Factors) through statistical modeling methods, historical accident databases, judgment from traffic experts, and literature review by considering design variable's characteristics, traffic accident rates, and traffic accident frequency. AMFs developed in this study include exclusive left-turn lane, exclusive right-turn lane, sight distance, and intersection angle. Predictabilities of the developed AMFs and the existing accident prediction models are compared with real accident historical data. The results showed that performances of the developed AMFs are superior to the existing statistical accident prediction models. These findings show that AMFs should be considered as a important process to develop safety design evaluation algorithms. Additionally, AMFs could be used as an index that can judge the impact of corresponding design variables on accidents in rural intersections.

A Study on the Performance Evaluation Measures of Traffic Signal Operation at Signalized Intersections by Utilizing Historical Data from Advanced Traveller Information System (첨단 교통 정보 시스템 누적 소통정보를 활용한 신호교차로 운영개선 효과평가를 위한 혼잡강도 지표 연구)

  • Cho, Yong-bin;Kim, Jin-tae
    • The Journal of the Korea Contents Association
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    • v.18 no.11
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    • pp.643-654
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    • 2018
  • In order to understand and manage traffic flows in urban areas in the past, a variety of traffic engineering theoretical indicators such as intersection lag and highway speed have been applied. However, these theories and indicators have been developed under the constraints of traffic engineering research before the construction of intelligent transportation system. Since the ATIS system currently exists, it is necessary to introduce a separate traffic engineering technology that utilizes the data. In this paper, it is aimed to confirm whether it is applicable to intermittent flow (approach road, intersection, control group, main road axis) by using 'congestion intensity' which is already used in traffic engineering field. The results of this study are as follows: (1) The traffic signal improvement effect of urban road access road, intersection road, control group, Two verification studies were performed to verify the derived congestion intensity index. (1) verification of congestion intensity threshold value analysis and (2) crossing improvement using the congestion intensity. Through verification, it was confirmed that it is possible to apply the congestion intensity in the inter - city intermittent flow using the 5 - minute unit speed data so as to be able to escape from the existing traffic signal operation management which is past passive and manpower limit.