• Title/Summary/Keyword: local distance

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Pre-resilience Group Activities Against a Forthcoming Big Flood Disaster in Tokyo Below-Sea-Level Area

  • Ichiko, Taro;Kato, Takaarki;Ishikawa, Kinji
    • 한국방재학회:학술대회논문집
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    • 2011.02a
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    • pp.3-8
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    • 2011
  • In April 2010, Japan Cabinet Office has published the first countermeasure report for severe flood disasters. This report showed various flood-disaster scenarios and factors that widened damages. One of important suggestions was to transmit precious information for long-distance evacuation. So far, local municipalities have made Flood Hazard Map to inform resident risk and evacuation. In this paper, cognition and effectiveness of a flood hazard map in the down ARAKAWA river Tokyo were measured by social questionnaire survey. In conclusion, there were 3 factors to effect validity of a flood hazard map. There were (1) commitment to their neighborhood organization, (2) experience of Kathleen typhoon in 1947 and (3) level of using targeted river. As results, a logical diagram about a flood hazard map perception was drawn and discussed from a view of community-based approach.

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Ant Colony System for Vehicle Routing Problem with Time Window (시간제약이 있는 차량경로문제에 대한 개미군집 시스템 해법)

  • Lee, Sang-Heon;Lee, Seung-Won
    • Journal of the Korean Operations Research and Management Science Society
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    • v.34 no.1
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    • pp.153-165
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    • 2009
  • This paper apollos an ant colony system (ACS) for the vehicle routing problem with time window (VRPTW). The VRPTW is a generalization of the VRP where the service of a customer can begin within the time windows defined by the earliest and latest times when the customer will permit the start of service. The ACS has been applied effectively in geographical environment such as TSP or VRP by meta-heuristic that imitate an ant's biologic special duality in route construction, 3 saving based ACS (SB-ACS) is introduced and its solution is improved by local search. Through iterative precesses, the SB-ACS is shown to drive the best solution. The algorithm has been tested on 56 Solomon benchmarking problems and compared to the best-known solutions on literature. Experimental results shows that SB-ACS algorithm could obtain food solution in total travel distance minimization.

A Method for Improving Accuracy of Object Recognition and Pose Estimation by Using Kinect sensor (Kinect센서를 이용한 물체 인식 및 자세 추정을 위한 정확도 개선 방법)

  • Kim, Anna;Yee, Gun Kyu;Kang, Gitae;Kim, Yong Bum;Choi, Hyouk Ryeol
    • The Journal of Korea Robotics Society
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    • v.10 no.1
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    • pp.16-23
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    • 2015
  • This paper presents a method of improving the pose recognition accuracy of objects by using Kinect sensor. First, by using the SURF algorithm, which is one of the most widely used local features point algorithms, we modify inner parameters of the algorithm for efficient object recognition. The proposed method is adjusting the distance between the box filter, modifying Hessian matrix, and eliminating improper key points. In the second, the object orientation is estimated based on the homography. Finally the novel approach of Auto-scaling method is proposed to improve accuracy of object pose estimation. The proposed algorithm is experimentally tested with objects in the plane and its effectiveness is validated.

A Path Planning of a Mobile Robot Using the Ultrasonic Sensor and Fuzzy Logic (초음파 센서와 퍼지로직을 이용한 이동로봇의 경로계획)

  • Park, Chang-Soo;Lee, Jong-Soo
    • Proceedings of the KIEE Conference
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    • 1999.11c
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    • pp.627-629
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    • 1999
  • The research fields of mobile robot consist of three parts. The first is path planning, the second is the application of new sensors, and the last is a combination of the communication technology and mobile robot. In this paper we treat the path-planning. We use a Bayesian probability map, Distance Transform and Fuzzy logic for a path-planning. DT and Fuzzy logic algorithms search for path in entire, continuous free space and unifies global path planning and local path planning. It is efficient and effective method when compared with navigators using traditional approaches.

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A study on the classifying vehicles for traffic flow analysis using LiDAR DATA

  • Heo J.Y.;Choi J.W.;Kim Y.I.;Yu K.Y.
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.633-636
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    • 2004
  • Airborne laser scanning thechnology has been studied in many applications, DSM(Digital Surface Model) development, building extraction, 3D virtual city modeling. In this paper, we will evaluate the possibility of airborne laser scanning technology for transportation application, especially for recognizing moving vehicles on road. First, we initially segment the region of roads from all LiDAR DATA using the GIS map and intensity image. Secondly, the segmented region is divided into the roads and vehicles using the height threshold value of local based window. Finally, the vehicles will be classified into the several types of vehicles by MDC(Minimum Distance Classification) method using the vehicle's geometry information, height, length, width, etc

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The Effects of Lift-Off from Wall Thinning Signal in Pulsed Eddy Current Testing

  • Park, Duck-Gun;Angani, C.S.;Kishore, M.B.;Kim, C.G.;Lee, D.H.
    • Journal of Magnetics
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    • v.17 no.4
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    • pp.298-301
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    • 2012
  • In order to know the effect of surface irregularity in the detection of local wall thinning of pipeline using pulsed eddy current (PEC), the lift-off effects on PEC signal have been investigated. Three kinds of parameters in the PEC signal, which is "peak amplitude", "time to peak amplitude" and "time to zero crossing" are analyzed to separate the lift-off effects in the PEC signal. The distance from sensor to the bottom of sample which is the total thickness of combined insulator and sample is kept constant. The magnitude of the differential peak amplitude is increased with increasing sample thickness, the time to peak amplitude is increased with increasing the sample thickness. To determine the effect of lift-off, a number of balanced transient responses combining wall thinning locations and lift-off distances were plotted.

An Experimental Study on Structure of Air-assist Spray with Air Entrainment (공기유입을 고려한 2유체 분무의 구조에 관한 실험적 연구)

  • Chae, H.C.;Kim, D.I.;Oh, S.H.
    • Journal of ILASS-Korea
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    • v.6 no.1
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    • pp.9-17
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    • 2001
  • The effect of air entrainment in twin-fluid spray structure is investigated experimentally by varing the amount of itemizing air. The air entrainment is expected to affect on droplet size and velocity, droplet number density, turbulent kinetic energy and vorticity. PDA(Phase Doppler Anemometer) and PIV(Particle Image Velocimetry) system are used to measure those important factors in analyzing spray structure. The results show that spray structure consists of three distinctive regions ; the atomizing region near nozzle, characterizing strong convective effect, the central core region where droplets are accelerated, and the spray sheath region where droplets are decelerated due to air entrainment. The local air entrainment rate is largest near nozzle, characterizing strong turbulent kinetic energy and vorticity but deceases along axial distance.

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An Analytical Modeling for Bridging Stress Function Involving Grain Size Distribution in a Polycrystalline Alumina (다결정 알루미나에서 결정립 크기 분포를 포함하는 Bridging 응력함수의 해석적 모델링)

  • 손기선;이성학;백성기
    • Journal of the Korean Ceramic Society
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    • v.31 no.12
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    • pp.1449-1458
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    • 1994
  • A new analytical model which can discribe the relationship between the bridging stress and the crack opening displacement was proposed to investigate the microstructural effect on the R-curve behavior in a polycrystalline alumina. The crack opening displacement according to the distance behind the stationary crack tip was measured using in-situ fracture technique in an SEM, and then used for a fitting procedure to obtain the distribution of bridging stress. The current model and an empirical power law relation were introduced into the fitting procedure. The results indicated that the bridging stress function and R-curve computed by the current model were consistent with those computed by the power law relation. The microstructural factor, e.g., the distribution of grain size, was also found to be closely related to the bridging stress. Thus, this model explained well the interaction effect between the distribution of bridging stress and the local-fracture-controlling microstructure, providing important information for the systematic interpretation of microfracture mechanism including R-curve behavior of a monolithic alumina.

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A Speech Waveform Forgery Detection Algorithm Based on Frequency Distribution Analysis (음성 주파수 분포 분석을 통한 편집 의심 지점 검출 방법)

  • Heo, Hee-Soo;So, Byung-Min;Yang, IL-Ho;Yu, Ha-Jin
    • Phonetics and Speech Sciences
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    • v.7 no.4
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    • pp.35-40
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    • 2015
  • We propose a speech waveform forgery detection algorithm based on the flatness of frequency distribution. We devise a new measure of flatness which emphasizes the local change of the frequency distribution. Our measure calculates the sum of the differences between the energies of neighboring frequency bands. We compare the proposed measure with conventional flatness measures using a set of a large amount of test sounds. We also compare- the proposed method with conventional detection algorithms based on spectral distances. The results show that the proposed method gives lower equal error rate for the test set compared to the conventional methods.

A New Trench Termination for Power Semiconductor Devices (전력소자를 위한 새로운 홈구조 터미네이션)

  • Min, W.G.;Park, N.C.
    • Proceedings of the KIEE Conference
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    • 1998.07d
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    • pp.1337-1339
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    • 1998
  • The trench termination scheme is introduced for high voltage devices. The curvature of the depletion region at field limiting ring is critical factor to determine the breakdown voltage. The smooth curvature of the depletion junction alleviate the electric field crowding effect around this region. In the trench field limiting ring, the radius of the depletion region is smaller than conventional field limiting ring, but the distance between every trench is spaced small enough to punchthrough before initiation of local breakdown. The trench field limiting ring on silicon can ne formed by RIE followed by oxidation on side wall surface of the trench, and polysilicon filling. The combined termination of this trench floating field ring and field plate have been designed and analyzed. The breakdown simulation by 2-dimensional TCAD shows that the cylindrical junction breakdown voltage for substrate doping might be 99 percent of the ideal breakdwon voltage for substrate doping concentration of $3\times10^{14}cm^{-3}$ with about $100{\mu}m$ of lateral termination width.

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