• Title/Summary/Keyword: Curved Parts

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The MPEG-7 based Video Database (MPEG-7에 기반한 동영상 데이터베이스)

  • Lee, Soon-Hee
    • Journal of the Korea Computer Industry Society
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    • v.8 no.2
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    • pp.103-106
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    • 2007
  • In order to construct a Video Database, shot change detection should be made first. But, because these processes are not automated perfectly, we need a lot of time and efforts now. And, there are many shot change detection algorithms, which can't always insure the perfect result because of the editing effects such as cut, wipe, and dissolves used in film production. Therefore, in order to receive the exact shot change, It needs the verification and correction by manual processing at any cost. Spatiotemporal slice is a simple image condensing method for the content changes of video. The editing effects are expressed on the Spatiotemporal slice in the visually noticed form of vertical line, diagonal line, curved line and gradual color changes, etc. Accordingly the parts doubted as a shot change can be easily detected by the change of the Spatiotemporal slice without replaying the video. The system proposed in this study makes it possible to delete the false detected key frames, and create the undetected key frames on the Spatiotemporal slice.

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A Study on the application of Roof Truss Sliding Method in the Incheon International Amort Transportation Center - Great Hall (Roof Truss Sliding 공법 적용사례 연구 인천국제공항 교통센터 - Great Hall)

  • Lee Dong-Ryul
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • autumn
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    • pp.214-221
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    • 2001
  • The Great Hall of Incheon International Airport Transportation Center has irregular curved roof structure. The structure consists of 13 main steel trusses. (the longest span of 162m, 480ton) The total weight of the truss is 6,300ton and the whole truss is made of 9,600 pieces which has the joint connected to maximum 13 different parts at one point and Roof Truss is supported by 12 Fabric Foundation. Considering the economical efficiency and the schedule, the Sliding Construction Method was used other than conventional erection method. The roof truss structure was divided into two blocks, 3,550ton and 2,700ton, each block was pre-erected on the Giant Sleigh off the site and was pulled 181m by using Tandem Pulling Jack and Strand to be set in place.

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Germ cell Differentiation During Spermatogenesis, and Ultrastructural Characteristics of Mature Sperm in Male Phacosoma japonicus (Bivalvia: Veneridae)

  • Kim, Jin-Hee;Chung, Ee-Yung;Choi, Moon-Sul;Lee, Ki-Young;Lee, IL-Ho;Seo, Won-Jae
    • The Korean Journal of Malacology
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    • v.27 no.1
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    • pp.55-65
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    • 2011
  • Some characteristics of germ cell differntiations during spermiogenesis and mature sperm ultrastructure in male Phacosoma japonicus were investigated by transmission electron microscope observations. The morphology of the spermatozoon of this species has a primitive type and is similar to those of other species in the subclass Heterodonta. Morphologies of the sperm nucleus and the acrosome of this species are the cylindrical type and cap shape, respectively. The spermatozoon is approximately 45-50 ${\mu}m$ in length, including a long curved sperm nucleus (about $3.70{\mu}m$ long with 45 $^{\circ}$ of the angle of the nucleus, an acrosome (about $0.55{\mu}m$ in length), and tail flagellum (about 42-$47{\mu}m$)The axoneme of the sperm tail shows a 9+2 structure. As some characteristics of the acrosomal vesicle structures, the basal and lateral parts of basal rings show electron opaque part (region), while the anterior apex part of the acrosomal vesicle shows electron lucent part (region). These characteristics of the acrosomal vesicle were found in the family Veneridae and other several families in the subclass Heterodonta. These common characteristics of the acrosomal vesicle in the subclass Heterodonta can be used for phylogenetic and systematic analysis as a taxonomic key or a significant tool. The number of mitochondria in the sperm midpiece of this species are four, as one of common characteristics appear in most species in the family Veneridae and other families in the subclass Heterodonta. However, exceptionally, only three species in Veneridae of the subclass Heterodonta contain 5 mitochondria. The number of mitochondria in the sperm midpiece can be used for the taxonomic analysis of the family or superfamily levels as a systematic key or tools.

Electrical Resistance Measurement in Characterizing the Internal Damage of Carbon Nanotube/Polypropylene Nanocomposites (전기저항 측정법을 이용한 탄소나노튜브/폴리프로필렌 나노복합재료의 내부 손상 예측)

  • Kim, Hak-Soo;Kwon, Dong-Jun;Wang, Zuo-Jia;Gu, Ga-Young;Kim, Dae-Sik;Lee, Chun-Soo;Park, Joung-Man
    • Composites Research
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    • v.26 no.3
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    • pp.201-206
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    • 2013
  • The electrical resistance measurement was investigated as a damage monitoring method. In this study, 0.5 wt% Carbon nanotube reinforced polypropylene (CNT/PP) composites were evaluated under compressive fatigue loading. The shape of specimens was $20^{\circ}$ curved round type. Compression strength and electrical resistance were measured at different sections of specimen during compression. The microcracks of CNT/PP composites were detected based on the changing ratio of electrical resistance. Micro-damage during compressive fatigue test could be detected by electrical resistance measurements. The reason is that the contact points of CNTs in composites decreased under fatigue loading. During compressive fatigue test, larger change of electrical resistance was detected at the microcrack sections. It was proved that microcracks could be detected by electrical resistance measurement under compression test, whereas the real delamination parts were consistent with the predicted results by electrical resistance measurement.

A Study of Jeogori Design Pattern using the Pattern Analysis in the Books Entitled Hanbok Construction Focusing on the Women in 20's (성인여성 저고리 패턴을 활용한 개선된 저고리 패턴설계연구 - 20대 여성용 저고리를 중심으로 -)

  • Kim, Hyun-Ju;Chang, Min-jung
    • Journal of the Korea Fashion and Costume Design Association
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    • v.17 no.4
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    • pp.1-14
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    • 2015
  • This study mainly analyzes that designing patterns of an adult women Jeogori that takes advantage of patterns from each textbooks and complements the disadvantages based on the analysis of data from the dress evaluation and comparison of materials. The modification of a size specification is needed for the standard body as an adjust of the length of Jogori between front and back, mediation for bust width between front and back, a movement for the based line of Sup and Godae. As a result, the suitable pattern according to the standard somatotype is as below. Jeogori Length of front is determined by the length of back which was measured from side neck point to bust point plus three centimeters, and give three and half centimeters more in front. This three and half centimeters is for the curved in front of your body due to the chest. Bust width of front and back have to show the differences of human body. Bust width of front is calculated as bust girth into quarters and add two centimeters. Bust width of back gives one centimeter behind the curve from the center line in order to reduce the floating phenomenon. So, the amount of center back line dart is one centimeter. Arm hole girth measures as dividing bust girth into four. Also, Goedae width has two methods to measure. First, divide bust girth into ten equal parts and subtract 0.5 centimeters from it. Second, measure neck girth and divide it by four. Sleeve length is equal to Hwajang minus bust width of front. Hand wrist calculates in using bust girth. Make bust girth into quarters and multiply three fifths. Side line measures as deducting from Jeogori length of back to Arm hole girth and multiply two thirds.

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A Study on Resonance Frequencies of a Whispering Gallery Mode Dielectric Resonator Considering Electromagnetic Coupling Phenomena with an Excitation Part (여기부와의 전자파 결합 현상을 고려한 위스퍼링 갤러리 모드 유전체 공진기의 공진주파수에 관한 연구)

  • 황재효;민경일;구경완
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.9 no.5
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    • pp.603-613
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    • 1998
  • Resonant characteristic of Whispering modes(W. G. mode) on a dielectric disk resonator is influenced by an external circuit that is placed near the disk to excite this type of modes. In order to evaluate this phenomenon, we divide the disk resonator as two parts; a coupling part in which the mode coupling occurs and on uncoupled region. In the coupled part, we regard the part of the disk as a curved waveguide which is loaded with matched circuit, and derive a coupled mode equation for nonparallel dielectric waveguides. From the coupled mode equation, we calculate coupling coefficients and a coupled electromagnetic field. By using the complex coupling coefficients, we can calculate power transfer. We also calculate a resonant frequency in consideration of the mode coupling phenomenon. The calculated resonance frequence is confirmed by experiment for the resonance characteristics. As the results, it is found that the discrepancy between the theoretical and the experimental resonance frequencies is about 1.28% and the discrepancy between theory and experiment of FSR is about 0.6%.

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A study on the analysis and counterplan of Line 5 EMU Inverter Failure (서울 지하철 5호선 전동차 인버터장치의 장애 분석)

  • Choi, Yong-Woon;Koo, Jeong-Seo;You, Won-Hee;Koh, Hyo-In
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.509-517
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    • 2008
  • Rolling stock is the method of railway transportation. Especially, in the subway system which has short headways particularly during the rush hours, even one train's trouble on the main line might influence the whole line. Accordingly, to prevent a train trouble on the main line, high expense is used for the maintenance parts, workforce and facilities, etc. according to the preventive maintenance program. Therefore, in designing a EMU, emphasis should be put on the minimization of trouble and its extending influence on the mainline with the priority of safety and reliability. Seoul subway line 5 is the line that complements the first stage Seoul subway(lines 1,2,3 and 4) and is built deeply with many curved sections causing lots of dust. Studies were made to find out the importance of car design, selection of specifications and continuous maintenance on the basis of the analysis and countermeasure of the line 5 EMU inverter trouble case.

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Impact Localization Using Piezoelectric Paint Sensor with Mosaic Pattern Electrodes (모자이크 패턴 전극 압전 페인트 센서를 이용한 충격 위치 검출)

  • Kang, Sang-Hyeon;Kang, Lae-Hyong
    • Journal of Aerospace System Engineering
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    • v.13 no.2
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    • pp.19-25
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    • 2019
  • To detect the impact location of a structure, the authors' group conducted a study on piezoelectric paint sensor. The piezoelectric paint sensors are used for impact detection due to their inherent characteristics: sensitivity to high-frequency signal and impact. Additionally, the paint sensor can be applied on curved and complex structures where ceramic sensor would not be applicable. Moreover it is a self-powered sensor therefore no need for an external power source. For impact localization, mosaic pattern electrodes were coated on the specimen and the impact signal obtained from any part of the electrode where the impact occurred. If we more precise impact localization is required, the electrodes should be divided into more parts and impact data acquisition conducted in all the points of the electrode. In this paper, we developed a light, cheap and simple multi-channel data acquisition system to aid in data gathering. In total four channels data acquisition have been tested using the ARM Cortex-M3.

Blast Overpressure Evaluation for Blast Valves in Protective Tunnels with Rectangular-Shaped Tunnel Entrances (각형 출입구를 갖는 방호터널의 방폭밸브에 미치는 폭압 평가)

  • Pang, Seungki;Shin, Jinwon
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.17 no.4
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    • pp.79-90
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    • 2021
  • This paper presents a study to reduce the effect of blast pressure on the blast valves installed in protection tunnels, where the shape of the tunnel entrance and the blast pocket is optimized based on the predetermined basic shape of the protective tunnels. The reliability of the numerical tunnel models was examined by performing analyses of mesh convergence and overpressure stability and with comparison to the data in blast-load design charts in UFC 3-340-02 (DoD, 2008). An optimal mesh size and a stabilized distance of overpressure were proposed, and the numerical results were validated based on the UFC data. A parametric study to reduce the blast overpressures in tunnel was conducted using the validated numerical model. Analysis was performed applying 1) the entrance slope of 90, 75, 60, and 45 degrees, 2) two blast pockets with the depth 0.5, 1.0, and 1.5 times the tunnel width, 3) the three types of curved back walls of the blast pockets, and 4) two types of the upper and lower surfaces of the blast pockets to the reference tunnel model. An optimal solution by combining the analysis results of the tunnel entrance shape, the depth of the blast pockets, and the upper and lower parts of the blast pockets was provided in comparison to the reference tunnel model. The blast overpressures using the proposed tunnel shape have been reduced effectively.

Implementation of an Autonomous Driving System for the Segye AI Robot Car Race Competition (세계 AI 로봇 카레이스 대회를 위한 자율 주행 시스템 구현)

  • Choi, Jung Hyun;Lim, Ye Eun;Park, Jong Hoon;Jeong, Hyeon Soo;Byun, Seung Jae;Sagong, Ui Hun;Park, Jeong Hyun;Kim, Chang Hyun;Lee, Jae Chan;Kim, Do Hyeong;Hwang, Myun Joong
    • The Journal of Korea Robotics Society
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    • v.17 no.2
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    • pp.198-208
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    • 2022
  • In this paper, an autonomous driving system is implemented for the Segye AI Robot Race Competition that multiple vehicles drive simultaneously. By utilizing the ERP42-racing platform, RTK-GPS, and LiDAR sensors provided in the competition, we propose an autonomous driving system that can drive safely and quickly in a road environment with multiple vehicles. This system consists of a recognition, judgement, and control parts. In the recognition stage, vehicle localization and obstacle detection through waypoint-based LiDAR ROI were performed. In the judgement stage, target velocity setting and obstacle avoidance judgement are determined in consideration of the straight/curved section and the distance between the vehicle and the neighboring vehicle. In the control stage, adaptive cruise longitudinal velocity control based on safe distance and lateral velocity control based on pure-pursuit are performed. To overcome the limited experimental environment, simulation and partial actual experiments were conducted together to develop and verify the proposed algorithms. After that, we participated in the Segye AI Robot Race Competition and performed autonomous driving racing with verified algorithms.