• Title/Summary/Keyword: construction control

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Recognition of surface orientations in an object using photomeric stereo method (포토메트릭 스테레오를 이용한 물체표면방향의 인식)

  • 이종훈;전태현;김도성;이명호
    • 제어로봇시스템학회:학술대회논문집
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    • 1990.10a
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    • pp.816-820
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    • 1990
  • This paper is pre-stage for getting EGI which can be used for modeling of an object. It discusses the construction of the vision processing system and its algorithm for getting needle diagram from tie object image. We realize the algorithm with monocular camera system, using Reflectance Map theory and photometric stereo method. We can calculate the surface normal at any point in the image if we take multiple images at the different lighting conditions. From the 3 images taken from different lighting conditions through the experiment, we get the needle diagrams of the sphere and the object. We confirm the validness of the surface, normal acquisition algorithm comparing the experimental needle diagram with the ideal one obtained from the surface normal of the known object.

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Diagnosis of Crack Occurrence of Very-Early Strength Latex-Modified Concretes through Field Tests (현장실험을 통한 VES-LMC 균열발생 원인분석)

  • Choi, Pan-Gil;Lee, Bong-Hak
    • Journal of Industrial Technology
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    • v.26 no.A
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    • pp.139-146
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    • 2006
  • Many concrete bridge decks develop transverse cracking shortly after construction. These cracks accelerate corrosion of reinforcing steel and lead to concrete deterioration, damage to components beneath the deck, unsightly appearance. These cracks shorten the service life and increase maintenance costs of bridge structures. In this study, VES-LMC overlay, which provides the same benefits as a conventional overlay, is designed to cure very quickly. Although the materials for VES overlays are more expensive, the cost is more than offset by the savings on traffic control and work zone safety measures. Otherwise, reaction of hydration occurs very rapidly in beginning step(concrete placing). As a results, thermal cracking can be occur by thermal stress in accordance with hydration-heat The purpose of this study was to estimate diagnosis of crack occurrence of VES-LMC through field tests at early-age.

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The Study of Tilting Control System for Tilting Vehicle (틸팅차량용 틸팅제어시스템 기술개발에 관한연구)

  • Lee, Su-Gil;Han, Seong-Ho;Han, Young-Jae;Lee, Woo-Dong;Song, Yong-Soo
    • Proceedings of the KIEE Conference
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    • 2004.04a
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    • pp.229-231
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    • 2004
  • Tilting trains are now an established feature of railway operations throughout the world. For intercity traffic, tilt provides operators with increasing speeds, and therefore enhanced competitiveness, on existing routes where insufficient traffic or a lack of funds precludes the construction of a dedicated new high-speed railway. Appling the tilting train, we can expect 30% of speed up on existing lines, but the stability of the electric current would be low because of tilting the train. Also, the spark between the catenary and pantagraph cause environmental problems such as noise, radio wave malfunction. Therefore, the tilting on pantagraph for the power suppling device is very essential for stable electric power supply.

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A Study on the Analysis of Accidents for Reinforced concrete Method and Pre-cast concrete Method (재래식 철근콘크리트 공법과 조립식 콘크리트 공법에서의 사고 분석에 관한 조사 연구)

  • Park, Jong-Keun
    • Journal of the Korean Society of Safety
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    • v.10 no.4
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    • pp.81-86
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    • 1995
  • In order to apply to analysis methods of mechanism and cross tabulation methods for the influence factors by the accident types to the object of accidents which occurred in R.C and P.C methods among the accidents in construction work sites, the latent hazards in P.C method are evaluated from the data of accidents in H Company from Jan. 1, 1993 to Dec. 31, 1993. The relationship between accident types and unsafe acts, unsafe conditions are recognized and the hazards of R.C method and P.C method are compared from the data acquired by the analysis of causes for a kind of occurrence mechanism. In conclusions, the items such as causes of accidents, accidents types, occurrence time, and the characteristics, are concentrated on one side in the P.C method, which is quite different from R.C method. Therefore the control method for the accident causes is easily established with a lot of effective advantages. The frequency and severity of accidents in P.C method are so low in comparison with R.C method.

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Mechanical strengths of self compacting concrete containing sawdust-ash and naphthalene sulfonate

  • Elinwa, Augustine U.;Mamuda, Mamuda;Ahmed, M.
    • Advances in concrete construction
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    • v.2 no.4
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    • pp.301-308
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    • 2014
  • The present research work is on the effect of sawdust ash (SDA) on the mechanical strengths of self compacting concrete (SCC) using naphthalene sulfonate (NS) as a plasticizer. Experiments on compressive, flexural and splitting tensile strengths are conducted and the data analyzed using the Minitab 15 software. The results showed that SDA can defer the reaction of cement hydration and prolong the setting times of cement paste. This was very much pronounced on the flexural and splitting tensile strengths at 90 days of curing which are 36 % and 33 % higher than the control strengths, respectively. The study has proposed strength relations of mortar compressive strength with the flexural and splitting tensile strengths and these are, 5 and 7 times respectively. The flexural strength is 1.5 times that of the splitting tensile. Finally, linear models were developed on these relationships.

Development of an Automatic Two-Dimensional Mesh Generator using an Inward Offset Boundary Technique

  • Choi, Jin-Woo;Kim, Yohng-Jo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.2 no.4
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    • pp.61-66
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    • 2003
  • An excellent mesh construction is of Importance in yielding good results of finite element analysis. The new mesh generation algorithm, which offsets boundaries inward, was developed on the basis of a looping method. An user interface technique and automatic splitting lines which both divide a given domain into subdomains manually or automatically, were used. In addition, the separation method has advantages to prevent the large scale of element size and to control numbers of nodes and elements. This new mesh generation algorithm was proved in practice.

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Development of a hull-plate moving robot with permanent magnets (영구자석을 이용한 선체 외판 주행 로봇 개발)

  • Kim, Eun-Young;Lee, Dong-Hoon;Kim, Ho-Kyeong
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.990-995
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    • 2008
  • During the ship's construction process, most high place workings have been carried out by human power, like welding, grinding and so on. Because of the ability to relieve human beings from these, the need of developing a hull-plate moving robot has been rising. This paper describes a hull-plate moving robot, using magnet modules as the adhesive method. Magnet modules maintain the magnetic force between hull-plate and magnets constantly. So that allows the robot to perform movements on the curved plate without the loss of adhesive force. The robot consists of driving motors, control system and magnet modules. The performance of the robot is verified on the curved plate.

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Fault Tree Analysis based on State-Transition Model (상태 전이 모델 기반 결함 트리 분석)

  • Chung, In-Sang
    • The Journal of the Korea Contents Association
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    • v.11 no.10
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    • pp.49-58
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    • 2011
  • Fault Tree Analysis(FTA) builds fault trees to perform safety analysis of systems. However, building fault trees depends on domain knowledge and expertize on target systems and consumes lots of time and efforts. In this paper, we propose a technique that builds fault trees systematically based on state-transition models which are software design artifacts. For the end, this paper identifies conditions that should be satisfied to guarantee safety of state-transition models and develop templates for fault tree construction. This paper also describes the results of appling the proposed method to railway crossing control system.

A Construction of Wireless Home Automation System with Low Cost and High Efficiency (저비용, 고효율의 무선가정자동화 시스템 구축방향 연구)

  • 신경철;오용선
    • Proceedings of the Korea Contents Association Conference
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    • 2004.05a
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    • pp.357-364
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    • 2004
  • Government is supporting development of home networking. But, this new system is much expensive to introduce in the home. And limit for establishment is so many in the home. Therefore, in this paper, Present direction of home automation system that can have high effciency into low expense, induction of automation system is easied in the home. Also, install can be easy and do remote control in PC, HP, PDA because use RF, DB.

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A Study on the Dynamic Characteristics of the Gas Spring on the Automotive Application (차량 장착상태에서의 가스 스프링 동적 특성 연구)

  • Lee, Choon Tae
    • Journal of Drive and Control
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    • v.12 no.4
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    • pp.15-20
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    • 2015
  • Unlike a typical metal spring, a gas spring uses compressed gas contained in a cylinder and compressed by a piston to exert a force. A common application includes automobiles where gas spring are incorporated into the design of open struts that support the weight of tail gate. They are also used in furniture such as office chairs, and in medical and aerospace applications. The gas spring works by the application of pressurized gas (nitrogen) contained in a cylinder. The internal pressure of the gas spring greatly exceeds atmospheric pressure. This differential in pressure exists at any rod position and generates an outward force on the rod, making the gas spring extend. In this paper, we investigated the dynamic characteristics of a gas spring on an automotive tail gate system.