• Title/Summary/Keyword: Joint system

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A Study on the Evaluation of Tensile Performance According to Pareral Jointing Methods of the Sheet Membrane Waterproofing System (방수시트의 평행접합방법에 따른 인장성능 평가연구)

  • Lee Jeoung-Yun;Oh Mi-Hyun;Kwak Kyu-Sung;Oh Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • v.y2004m10
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    • pp.39-44
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    • 2004
  • A heat and room temperature construction method of asphalt have been mainly applying to rooftop waterproofing in concrete structure, and the rest construction method are sheet, membrane and mortar waterproofing construction method. In particular, joint method in sheet waterproof method is as overlap joint which on being reinforced with fiber and tape, have been applying for job site to mechanical fix using protection disk and anchorage and metal ironwork on the end of sheet. These construction method cause cutting off joint of sheet as behavior of structure according to repairs of sheet itself and thermal conduct, outdoor air environment. In conclusion, we analyzed and examined the application of various sheets and piece ashes about superior 'I' joint which divide from one and the other sheet and progressed about joint construction method of fixing method for overlap.

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Performance Improvement of Iterative Demodulation and Decoding for Spatially Coupling Data Transmission by Joint Sparse Graph

  • Liu, Zhengxuan;Kang, Guixia;Si, Zhongwei;Zhang, Ningbo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.12
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    • pp.5401-5421
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    • 2016
  • Both low-density parity-check (LDPC) codes and the multiple access technique of spatially coupling data transmission (SCDT) can be expressed in bipartite graphs. To improve the performance of iterative demodulation and decoding for SCDT, a novel joint sparse graph (JSG) with SCDT and LDPC codes is constructed. Based on the JSG, an approach for iterative joint demodulation and decoding by belief propagation (BP) is presented as an exploration of the flooding schedule, and based on BP, density evolution equations are derived to analyze the performance of the iterative receiver. To accelerate the convergence speed and reduce the complexity of joint demodulation and decoding, a novel serial schedule is proposed. Numerical results show that the joint demodulation and decoding for SCDT based on JSG can significantly improve the system's performance, while roughly half of the iterations can be saved by using the proposed serial schedule.

Structural Joint Damage Assessment using Neural Networks (신경망을 이용한 구조물 접합부의 손상도 추정)

  • 방은영
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1998.04a
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    • pp.131-138
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    • 1998
  • Structural damage is used to be modeled through reductions in the stiffness of structural elements for the purpose of damage estimation of structural system. In this study, the concept of joint damage is employed for more realistic damage assessment of a steel structure. The joint damage is estimated damage based on the mode shape informations using neural networks. The beam-to-column connection in a steel frame structure is represented by a rotational spring at the fixed end of a beam element. The severity of joint damage is defined as the reduction ratio of the connection stiffness with respect to the value of the intact joint. The concept of the substructural identification is used for the localized damage assessment in a large structure. The feasibility of the proposed method is examined using an example with simulated data. It has been found that the joint damages can be reasonably estimated for the case with the measurements of the mode vectors subjected to noise.

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Crack control of precast deck loop joint using high strength concrete

  • Shim, Changsu;Lee, Chi dong;Ji, Sung-woong
    • Advances in concrete construction
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    • v.6 no.5
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    • pp.527-543
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    • 2018
  • Crack control of precast members is crucial for durability. However, there is no clear provision to check the crack width of precast joints. This study presents an experimental investigation of loop joint details for use in a precast bridge deck system. High strength concrete of 130 MPa was chosen for durability and closer joint spacing. Static tests were conducted to investigate the cracking and ultimate behavior of test specimens. The experimental results indicate that current design codes provide reasonable estimation of the flexural strength and cracking load of precast elements with loop joint of high strength concrete. However, the crack width control of the loop joints with high strength concrete by the current design practices was not appropriate. Some recommendations to improve crack control of the loop joint were derived.

Study of east & west medical science documentary records of Hip joint pain (고관절(股關節) 질환(疾患)의 동서양의학적(東西洋醫學的) 고찰(考察))

  • Kim, Hyun-Soo;Kang, Jun-Hyuk;Hong, Seo-Young;Yoon, Il-Ji;Oh, Min-Seok
    • Journal of Haehwa Medicine
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    • v.15 no.1
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    • pp.125-140
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    • 2006
  • Study of east & west medical science documentary records of Hip joint pain lead to following conclusions. 1. Easten medicine classify hip joint pain with terms "Bi-chu-tong", "Bi chu in tong" "Bi-chu-choong-tong". 2. Easten medicine asorts cause of hip joint pain with external factor, such as exogenous energy, six yin evil energy and intrinsic factor, which are weakness caused by prolonged deasease, warm-heat evil. 3. In western medicine, causes that trigger hip joint pain are trauma, fracture, dislocation,and bacterial infection. 4. Treatment of hip joint disorder in western medicine, physiotherapy concerning conservative treatment, and pain control with drug treatment, kinesitherapy are used, and concernig fracture, operation is used. 5. In Eastern medicine, principle of treating hip joint pain, sung-juk-sa-ji(盛則寫之), hu-juk-bo-ji(虛則補之), yul-juk-jil-ji(熱則疾之), han-juk-yu-ji(寒則留之), ham-ha-juk-chim-ji(陷下則沈之), bul-sung-bul-hu(不盛不虛), yi-kyong-chui-ji(以經取之) is presented. This priciple of treatment was descended through ages and is now applied to treatments such as Acupuncture, Herbal, physical treatment based on so-san-eo-hyul(消散瘀血), seo-kun-tong-rak(舒筋通絡), so-ri-kwan-jul(疏利關節) principle. 6. In Eastern medicine, meridians used to treat hip joint pain are The Chok yangmyung wi Kyong(足陽明胃經), Chok taeum bi Kyong(足太陰脾經), Chock soyang dam Kyong(足少陽膽經), Chock guelum gan Kyong(足厥陰肝經). In conclusion, hip joint pain should be considered in relationship with internal organs and whole body system. Western & Eastern point of view should be carefully inspected and connected and intensive study of nervous system and meridian is required, in order to adopt best treatment for the patients.

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Estimation Method of Key Block Size on a Large Scale Rock Slope by Simulation of 3-D Rock Joint System (3차원 절리계 모사를 통한 대규모 암반비탈면 파괴블록크기 추정방법)

  • Kim, Dong-Hee;Jung, Hyuk-Il;Kim, Seok-Ki;Lee, Woo-Jin;Ryu, Dong-Woo
    • Journal of the Korean Geotechnical Society
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    • v.23 no.10
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    • pp.97-107
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    • 2007
  • Accurate evaluation of the slope stability by assuming failure block as the entire slope is considered to be apposite for the small scale slope, whereas it is not the case for the large scale slope. Hence, appropriate estimation of a failure block size is required since the safety factor and the joint strength parameters are the function of the failure block size. In this paper, the size of failure block was investigated by generating 3-dimensional rock joint system based on statistical data of joints obtained from research slope, such as joint orientation, spacing and 3-dimensional joint intensity. The result indicates that 33 potential failure blocks exist in research slope, as large as 1.4 meters at least and 38.7 meters at most, and average block height is 15.2 meters. In addition, the data obtained from 3 dimensional joint system were directly applicable to the probability analysis and 2 and 3 dimensional discontinuity analysis.

Development of web based shape inspection system for the forging products having complicated shapes (인터넷을 이용한 정밀단조품의 품질평가 시스템 개발에 관한 연구)

  • Park, K.S.;Kim, B.J.;Jang, J.H.;Moon, Y.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2006.05a
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    • pp.211-214
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    • 2006
  • The outer race of the constant velocity(CV) joint is an important load-supporting automotive part, which transmits torque between the transmission and the wheel. The outer race is difficult to forge, because its shape is very complex and the required dimensional tolerances are very stringent. Therefore, the internet based shape inspection system is developed in this study to provide quick and accurate data through the easy control from users. Proposed system uses mechanical displacement sensors to measure the shape of CV joint that has six inner ball grooves, and commercially available Lab-View program is used to process measured data into the dimensional shape. Developed program provides a simple user interface that enables users real-time access of data measured from industrial production lines. Furthermore, it can exchange measured data via the internet between users and forging system operators. A java applet helped the system connection via internet. A data, IP access, is transmitted to the packet by TCP/IP. Our proposed system has many advantages over current measuring systems including fast and efficient data processing by real-time control, and system flexibility.

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Effect of Joint Aperture Variation on Hydraulic Behavior of the 2-D DFN System (절리간극의 변화가 이차원 DFN 시스템의 수리적 특성에 미치는 영향)

  • Han, Jisu;Um, Jeong-Gi
    • Tunnel and Underground Space
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    • v.26 no.4
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    • pp.283-292
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    • 2016
  • A computer program code was developed to estimate hydraulic behavior of the 2-D connected pipe network system, and implemented to evaluate the effect of joint aperture on hydraulic parameters of fractured rock masses through numerical experiments. A total of 216 stochastic 2-D DFN(discrete fracture network) blocks of $20m{\times}20m$ were prepared using two joint sets with fixed input parameters of joint orientation, frequency and size distribution. Two different cases of joint aperture variation are considered in this study. The hydraulic parameters were estimated for generated 2-D DFN blocks. The hydraulic anisotropy and the chance for equivalent continuum behavior of the DFN system were found to depend on the variability of joint aperture.

A Study on Crack Formation in the K11 Objective Individual Combat Weapon Fire Control System using Analysis of Variance (분산분석을 활용한 K11 복합형소총 사격통제장치 균열발생 원인 연구)

  • Shin, Sang-Sik;Kim, Byeong Kyu;Sim, Chul Bo
    • Journal of Korean Society for Quality Management
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    • v.43 no.3
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    • pp.289-298
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    • 2015
  • Purpose: This study examined the problem of crack formation in the fire control system(FCS) of the K11 objective individual combat weapon(OCIW), using design of experiment analysis. Three hypothesis were considered. The first hypothesis is that bolted joint has an effect on impulse caused by firing the weapon and the second hypothesis is that a short time interval of shooting has an effect on impulse and lastly, the third hypothesis is that a positive correlation has between the bolted joint of the FCS and the impulse. Methods: The relationship between the bolted joint and the impulse cause by firing the weapon were examined experimentally. The first and second hypothesis was tested using correlation analysis and the t-test. Results: Using ANOVA, the first null hypothesis was rejected and the alternative hypothesis was accepted. ANONA confirmed the second null hypothesis. Correlation analysis dismissed the last null hypothesis. A positive correlation between the bolted joint and the impulse caused by shooting the weapon was verified. Conclusion: The bolted joint of the K11 FCS and the barrel of the K11 affect the impulse caused by firing the weapon. A positive correlation was established between the bolted joint of the FCS and the impulse on firing the K11 OICW.

Experimental Study on the Load Transfer Behavior of Steel Grid Composite Deck Joint (격자형 강합성 바닥판 이음부의 하중전달 거동에 관한 실험적 연구)

  • Shin, Hyun-Seop
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.4
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    • pp.10-21
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    • 2014
  • The joint of prefabricated steel grid composite deck is composed of concrete shear key and high-tension bolts. The flexural and shear strength of the joint were experimentally evaluated only by the bending and push-out test of the joint element. In this study the lateral load transfer behavior of the joint in deck structure system is experimentally evaluated. Several decks connected by the joint are prefabricated and loaded centrically and eccentrically. In the case of centrically loaded specimens, the analysis results show that for the same loading step the rotation angle of the joint with 4 high-tension bolts is larger than the case of the joint with 9 high-tension bolts. Consequently, flexural stiffness of deck and lateral load transfer decrease in the case of specimen with 4 high-tension bolts. But, in the case of eccentrically loaded specimens, it is found that there are no significant differences in the load transfer behavior. The further analysis results about the structural behavior of the joint show that lateral load transfer can be restricted by the load bearing capacity of the joint as well as punching shear strength of the slab. Furthermore, considering that high-tension bolts in the joint didn't reach to the yielding condition until the punching shear failure, increase in the number of high-tension bolts from 4 to 9 has a greater effect on the flexural stiffness of the joint and deck system than the strength of them.