• Title/Summary/Keyword: detailed inspection

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Seismic assessment of historical masonry structures: The case of Amasya Taşhan

  • Karaca, Zeki;Turkeli, Erdem;Pergel, Senol
    • Computers and Concrete
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    • v.20 no.4
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    • pp.409-418
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    • 2017
  • Turkey owns a very important cultural and historical heritage that bears the traces of thousands of years of culture and civilization. It is an inevitable duty to carry these treasuries to the future generations. In this paper, structural safety assessment and strengthening stages of one of these important historical heritages namely Amasya Taşhan was investigated in details as a case study. For this purpose, the detailed architectural projects of the structure with the information of all load carrying and structural elements were prepared. Then, the structural dynamic analyses were performed by using SAP2000. The internal forces obtained from the dynamic analyses determined the weak regions. By obtaining the information from dynamic analyses, the method of state of the art technique of application of the structure that needs structural strengthening was selected. The last step is the application of these precautions to the whole structure. At the end of this study, this study not also contains several strengthening techniques that is used in one masonry structure together but also provides a useful reference to the practicing engineers.

A study on the TiN coating applied to a rolling wire probe

  • Song, Young-Sik;S. K. Yang;Kim, J.
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2003.10a
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    • pp.118-118
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    • 2003
  • In a rolling wire probe, a key component of an inspection apparatus for PDP electrode patterns, the electric performance of it is known to be strongly dependent on the surface condition of a collet pin, a needle pin, and a wire. However, the collet and needle pins rotate very rapidly in contact with each other, which results in the degradation of the surface by the heat and friction and finally the formation of black wear marks on the surface after a several hundred hours test. Once the black wear marks appear on the surface, the electric resistance of the probe increases sharply and so the integrity of the probe is severely damaged. In this experiment, TiN coating, which has excellent electric conductances and good wear-resistance, has been applied on the surface of collect and needle pins for preventing the surface damages. In order to achieve the homogeneous coating with a good adhesion property, special coating substrate stages and jigs were designed and applied during coating. TiN has been deposited using 99.999% Titanium target by a DC reactive sputtering method. According to the components and jigs, processing parameters, such as DC power, RF bias and the flow rate ratio of Ar and N$_2$ used as reactive gases, has been controlled to obtain good TiN films. Detailed problems and solutions for applying the new substrate stages and jigs will be discussed.

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Development on the Process Control System for Full Gate Visual Test of LCD Manufacturing Process (LCD 생산공정의 전게이트 시각 검사를 위한 공정 제어장치 개발)

  • Park, Hyoung-Keun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.7
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    • pp.1725-1728
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    • 2009
  • This research developed process control device and FGV pattern generating device essential for full gate visual inspection to improve process so that defect detection capability may be maximized in specified environment. The devices developed in this research, which can be swiftly replaced in case loss or error occurs, are anticipated to improve module yield as well as maintain tact loss near '0'. In addition, as a result of mounting H/W and S/W system to control detailed operation sequence in production line and executing performance check and verification, detection rates were 98.1% and 99.1% respectively for pixel defect by tact and line defect, and yield of the entire module process including gate and visual level test increased up to 98.3%.

A Study on Improvement of the Abnormal Operation of a One-shot Rifle with Bolt-action Operating System (볼트액션 작동방식 단발형 소총의 비정상 작동에 관한 개선 연구)

  • Shin, Jae Won;Jung, Chan Man;Choi, Si Young;Lee, Ho Jun;Shin, Tae Sung;Seo, Hyun Su
    • Journal of Korean Society for Quality Management
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    • v.47 no.3
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    • pp.417-424
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    • 2019
  • Purpose: In this study, the goal is to analyze this case to prevent the same accidents when using one-shot rifle. Methods: Detailed analysis of damaged parts must first be made in order to determine the cause of the abnormal explosion. The cause of abnormal operation can be determined by analyzing the information of damaged components and the firing mechanism of the weapon step by step. Also we can refer to a statement of shooter, witness and accident scene situation. Based on this theory, cause of abnormal firing can be narrow down. Results: Fracture of pin for fixing firing and latch is cause of abnormal operation of firing. Conclusion: It is deemed that periodic inspection and fundamental improvement of the structure are required to prevent the same accident as this.

Seismic assessment and retrofitting measures of a historic stone masonry bridge

  • Rovithis, Emmanouil N.;Pitilakis, Kyriazis D.
    • Earthquakes and Structures
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    • v.10 no.3
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    • pp.645-667
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    • 2016
  • The 750 m long "De Bosset" bridge in the Cephalonia Island of Western Greece, being the area with the highest seismicity in Europe, was constructed in 1830 by successive stone arches and stiff block-type piers. The bridge suffered extensive damages during past earthquakes, such as the strong M7.2 earthquake of 1953, followed by poorly-designed reconstruction schemes with reinforced concrete. In 2005, a multidisciplinary project for the seismic assessment and restoration of the "De Bosset" bridge was undertaken under the auspices of the Greek Ministry of Culture. The proposed retrofitting scheme combining soil improvement, structural strengthening and reconstruction of the deteriorated masonry sections was recently applied on site. Design of the rehabilitation measures and assessment of the pre- and post-interventions seismic response of the bridge were based on detailed in-situ and laboratory tests, providing foundation soil and structural material properties. In-situ inspection of the rehabilitated bridge following the strong M6.1 and M6.0 Cephalonia earthquakes of January 26th and February 3rd 2014, respectively, revealed no damages or visible defects. The efficiency of the bridge retrofitting is also proved by a preliminary performance analysis of the bridge under the recorded ground motion induced by the above earthquakes.

A New Extensive Census of Warped Disk Galaxies in Nearby Universe

  • Zee, Galaxy Woong-bae;Yoon, Suk-Jin
    • The Bulletin of The Korean Astronomical Society
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    • v.43 no.2
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    • pp.32.1-32.1
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    • 2018
  • The galactic warp is almost ubiquitous among disk galaxies and suspected to be an imprint of recent interactions with other galaxies. The detailed evolutionary course, however, is still uncertain due to the lack of observational evidence. To address this issue, we construct a new extensive catalog of 412 conspicuously warped disks at z = 0.01 ~ 0.05, based on SDSS DR7. We classify the warp morphology through a visual inspection from the Zooniverse Project and our new automated scheme for the warp measurement. We find an interesting color difference between S-and U-shaped warps. The U-type warp galaxies exhibits considerable color offset towards blue compared to both the S-type warps and the control sample of un-warped galaxies. The effect is even more pronounced for galaxies (a) with the greater warp amplitude and (b) with lower luminosity. This is the first piece of observational evidence that the S- and U-shaped warps are on different evolutionary phases in terms of not only dynamics but stellar populations as well. We discuss the implications in the context of the warp evolution theory.

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Flanking Sequence and Copy-Number Analysis of Transformation Events by Integrating Next-Generation Sequencing Technology with Southern Blot Hybridization

  • Qin, Yang;Woo, Hee-Jong;Shin, Kong-Sik;Lim, Myung-Ho;Cho, Hyun-Suk;Lee, Seong-Kon
    • Plant Breeding and Biotechnology
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    • v.5 no.4
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    • pp.269-281
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    • 2017
  • With the continual development of genetically modified (GM) crops, it has become necessary to develop detailed and effective molecular characterization methods to select candidate events from a large pool of transformation events. Relative to traditional molecular analysis methods such as the polymerase chain reaction (PCR) and Southern blot hybridization, next generation sequencing (NGS) technology for whole-genome sequencing of complex crop genomes had proven comparatively useful for in-depth molecular characterization. In this study, four transformation events, including one in Bacillus thuringiensis (Bt)-resistant rice, one in resveratrol-producing rice, and two in beta-carotene-enhanced soybeans, were selected for molecular characterization. To merge NGS analysis and Southern blot-hybridization results, we confirmed the transgene insertion sites, insertion construction, and insertion numbers of these four transformation events. In addition, the read-coverage depth assessed by NGS analysis for inserted genes might provide consistent results in terms of inserted T-DNA numbers in case of complex insertion structures and highly duplicated donor genomes; however, PCR-based methods can produce incorrect conclusions. Our combined method provides an effective and complete analytical approach for whole-genome visual inspection of transformation events that require biosafety assessment.

Blind Quality Metric via Measurement of Contrast, Texture, and Colour in Night-Time Scenario

  • Xiao, Shuyan;Tao, Weige;Wang, Yu;Jiang, Ye;Qian, Minqian.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.11
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    • pp.4043-4064
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    • 2021
  • Night-time image quality evaluation is an urgent requirement in visual inspection. The lighting environment of night-time results in low brightness, low contrast, loss of detailed information, and colour dissonance of image, which remains a daunting task of delicately evaluating the image quality at night. A new blind quality assessment metric is presented for realistic night-time scenario through a comprehensive consideration of contrast, texture, and colour in this article. To be specific, image blocks' color-gray-difference (CGD) histogram that represents contrast features is computed at first. Next, texture features that are measured by the mean subtracted contrast normalized (MSCN)-weighted local binary pattern (LBP) histogram are calculated. Then statistical features in Lαβ colour space are detected. Finally, the quality prediction model is conducted by the support vector regression (SVR) based on extracted contrast, texture, and colour features. Experiments conducted on NNID, CCRIQ, LIVE-CH, and CID2013 databases indicate that the proposed metric is superior to the compared BIQA metrics.

Study on the Stability Evaluation of Concrete Erosion Control Dam by using Non-destructive Test for Compressive Strength (콘크리트 비파괴시험법을 이용한 사방댐 안정도 평가에 관한 연구)

  • Park, Ki-Hyung;Kim, Min-Sik;Joh, Sung-Ho;Lee, Chang-Woo;Youn, Ho-Joong;Kim, Kyong-Ha
    • Journal of Korean Society of Forest Science
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    • v.102 no.1
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    • pp.90-96
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    • 2013
  • This study was conducted to investigate a stability trend within 6 above average and 4 blow average erosion control dams, which were selected by The Korean Association of Soil and Water Conservation and were built in 1990s in Gyeonggi and Gangwon Province. The study was aimed to measure rebound hardness of upstream face, flood way and downstream face from those dams selected by using 'Concrete Test Hammer'. The main purposes of the study are selection of compression strength prediction equation and scope of wavelength, which successfully demonstrate non-destructive test results for erosion control dams. There is an opportunity to increase disaster prevention ability when stability vulnerability of concrete erosion control dam is detected in a timely manner. Results of the compression strength investigation express that there is a consistency with visual inspection of stability that has been processed by The Korean Association of Soil and Water Conservation. We concluded that a prediction equation, which was developed by Architectural Institute of Japan (AIJ), shows highest suitability in Korean erosion control dams when stability investigation is performed. The detailed criteria for the test result are 'stable', 'detail inspection required' and 'poor' for over 300 $kgf/cm^2$, 250~300 $kgf/cm^2$ and below 250 $kgf/cm^2$ respectively. Standards for stability of Korean erosion control dam and a compression strength prediction equation (that corresponds to the standards of the stability) should be established on the basis of chronological data of erosion control dam compression strength. Systematical approach for stability inspection that carries out remodeling or repair when problem on erosion control structures are detected through visual inspection and simple stability test, is necessary for the future disaster prevention.

Development of Framework for Asset Management of Public Building (공공건축물의 자산관리 프레임워크 개발)

  • Cho, Sang-Ouk;Ko, Kyu-Jin;Hwang, Jeong-Ha;Lee, Chan-Sik
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.19 no.2
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    • pp.133-142
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    • 2015
  • The budget for public buildings is expected to increase to their maintenance, and the systematic maintenance and sufficient budget are recognized as the important factors for building maintenance. In Korea, buildings are not systematically maintained due to the lack of manpower, expertise and basis of maintenance budget estimates. Compared with Australia where the facility maintenance is optimized through asset management, Korea has only passive maintenance systems that focus on regulations. The introduction of the systematic asset management is required to ensure the advanced building maintenance in Korea. In this study, the asset management processes for social infrastructure facilities in and out of Korea were analyzed, and the asset management framework for public buildings were established. The asset management procedure consisted of ordinary asset management procedure, selective asset value assessment. The framework in this study was developed focusing on the asset management task for public buildings and presented the detailed contents of each step. The application of this framework to the actual work will enable the systematic management of building's value and performance, and the efficient appropriation of the maintenance budget.