• Title/Summary/Keyword: damage diagnosis

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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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APPLICATION OF INFRARED THERMOGRAPHY IN DENTISTRY (치과에서의 적외선 체열사진의 응용)

  • Lee, Hoon;Kim, Su-Gwan
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.31 no.4
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    • pp.335-341
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    • 2005
  • This study discusses the effects of infrared thermography in dentistry. Infrared thermography allows the quantification of infrared rays and provides useful data for dental care and research. It has been used for the diagnosis of temporomandibular dysfunction (TMD) and proposed as an objective measure of myofascial pain. It is closely related to temperature and produces beneficial objective data. A study of the heat emissions from facial structures has the potential to benefit dental diagnosis of TMD, postoperative inferior alveolar damage, and endodontic and conservative treatments. In this paper, we assessed infrared thermography in dentistry and consider future developments of infrared thermography.

The Standardized Methods for Improvement of Maintenance Deterioration caused by Fire damage (국제 표준화를 위한 화재이후의 유지관리 시스템 개발)

  • Kwon, Young-Jin;Koo, In-Hyuk;Kim, Dong-Eun;Seo, Dong-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2013.11a
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    • pp.230-231
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    • 2013
  • A fire outbreak in a reinforcement concrete structure looses the organism by different contraction and expansion of hardened cement pastes and aggregate, and causes cracks by thermal stress, leading to the deterioration of the durability. So, concrete reinforcement structure is damaged partial or whole structure system. Therefore accurate diagnosis of deterioration is needed based on mechanism of fire deterioration in general concrete structures. Fundamental information and data on the properties of concrete exposed to high temperature are necessary for accurate diagnosis of deterioration. In this study, consider case of investigation methods and repair work in fire damaged structure concrete.

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The Standardized Methods for Improvement of Maintenance and Performance Construction of Deterioration caused by Fire damage (화재피해 콘크리트의 유지관리 및 시공성능 향상을 위한 표준화방안)

  • Seo, Dong-Goo;Kim, Dong-Eun;Kim, Bong-Chan;Kwon, Young-Jin
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2013.05a
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    • pp.16-18
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    • 2013
  • A fire outbreak in a reinforcement concrete structure looses the organism by different contraction and expansion of hardened cement pastes and aggregate, and causes cracks by thermal stress, leading to the deterioration of the durability. So, concrete reinforcement structure is damaged partial or whole structure system. Therefore accurate diagnosis of deterioration is needed based on mechanism of fire deterioration in general concrete structures. Fundamental information and data on the properties of concrete exposed to high temperature are necessary for accurate diagnosis of deterioration. In this study, consider case of investigation methods and repair work in fire damaged structure concrete.

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A study on the diagnosis of rater faults through the current analysis (전동기 전류분석을 통한 회전자회로 고장진단에 관한연구)

  • Lee, Y.S.;Kwon, J.L.;Lee, K.J.;Kim, H.S.
    • Proceedings of the KIEE Conference
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    • 2003.07b
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    • pp.801-803
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    • 2003
  • Faults in induction motors can be categorized into mechanical faults and electrical faults, and most mechanical faults result from inferiority or damage of the bearing, while most electrical faults derive from insulation faults of stator windings and rotor bar cracks. When a crack appears on the rotor bar, its efficiency decreases, which increases energy consumption and temperature, reducing the life span of the motor. This kind of fault can only be sensed by the protection relay after the condition has worsened to a certain degree, bringing massive economic loss. This paper will deal with the diagnosis method of rotor bar faults through the load current analysis method of the motor used during operation.

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Security Measures by Diagnosing Vulnerabilities in Web Applications

  • Kim, Hee Wan
    • International journal of advanced smart convergence
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    • v.10 no.4
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    • pp.22-29
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    • 2021
  • For web application vulnerability diagnosis, from the development stage to the operation stage, it is possible to stably operate the web only when there is a policy that is commonly applied to each task through diagnosis of vulnerabilities, removal of vulnerabilities, and rapid recovery from web page damage. KISA presents 28 evaluation items for technical vulnerability analysis of major information and communication infrastructure. In this paper, we diagnose the vulnerabilities in the automobile goods shopping mall website and suggest security measures according to the vulnerabilities. As a result of diagnosing 28 items, major vulnerabilities were found in three items: cross-site scripting, cross-site request tampering, and insufficient session expiration. Cookie values were exposed on the bulletin board, and personal information was exposed in the parameter values related to passwords when personal information was edited. Also, since the session end time is not set, it was confirmed that session reuse is always possible. By suggesting security measures according to these vulnerabilities, the discovered security threats were eliminated, and it was possible to prevent breaches in web applications and secure the stability of web services.

Occurrence of Plant-Parasitic Nematodes of Turfgrass in Korea

  • Mwamula, Abraham Okki;Lee, Dong Woon
    • The Plant Pathology Journal
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    • v.37 no.5
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    • pp.446-454
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    • 2021
  • Plant-parasitic nematodes are not only an important constraint on agricultural crop production, but also cause both direct and indirect damage to turfgrass, which is a ground cover plant. However, studies on plant-parasitic nematodes of turfgrass in Korea are scarce. A survey for plant-parasitic nematodes was carried out on 13 golf courses in Korea. The results yielded 28 species/taxa belonging to 16 genera and 12 families of plant-parasitic nematodes. Among the isolated species, Helicotylenchus microlobus, Mesocriconema nebraskense, Tylenchorhynchus claytoni, Mesocriconema sp., and Meloidogyne graminicola were the most prevalent species in all management zones. Twelve species were new records of plant-parasitic nematodes in Korea. Highest maximum densities were showed by T. claytoni, Paratylenchus nanus, M. nebraskense, M. graminicola, and H. microlobus. Diversity (H'), was significantly higher in fairways compared to tees and greens, though species evenness (J') and dominance (D) showed no statistically significant differences. This information is crucial in nematode problem diagnosis, and the subsequent formulation of management strategies.

Study of Condition Analysis and Diagnosis on Oil Paintings with Terahertz Imaging (테라헤르츠 이미징기법을 이용한 유화의 상태분석 및 진단)

  • Baek, Na Yeon;Song, You Na;Kim, Moon Jeong;Chung, Yong Jae;Lee, Han Hyoung
    • Journal of Conservation Science
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    • v.35 no.3
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    • pp.237-244
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    • 2019
  • In this study, we applied terahertz imaging technology to three Korean modern oil paintings ('Boy,' 'Girl,' and 'Hyehwadong Landscape'); investigated the types of inner layer information in the pictures that can be extracted with terahertz imaging technology; and analyzed the conditions for extracting them. The biggest problem in the terahertz imaging analysis we encountered was the image distortion caused by the change of the distance between the target surface and the terahertz detector, depending on the surface curvature of the target paintings. We then developed a 'working distance maintaining device' to solve this problem. As a result, the terahertz imaging technique was used to identify the base material characteristics and any patterns of damage inside, and presented the optimal conditions for identifying each characteristic. In addition, it was useful to employ the terahertz frequency-division image to check the characteristics of the background materials. To confirm coloring techniques such as brush strokes, it is effective to compare the maximum reflection peak image with the cross-section image; and to detect damage information inside the paintings that cannot be observed on the surface, to compare the cross-section image with the frequency-division image. On the other hand, according to the terahertz imaging analysis of the oil paintings, the internal structural damage marks of 'Boy' and 'Girl' were confirmed, and the artist's painting style was confirmed in 'Hyehwadong Landscape.' The above results are expected to be useful for the analysis and diagnosis of Korean modern oil paintings for their preservation.

The Standard Thesis of Objectivity Condition Evaluation for Infrastructure(Retaining Walls) (옹벽 시설물의 객관적인 상태평가 기준정립)

  • 이종영;신창건;장범수
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.06a
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    • pp.3.1-11
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    • 2003
  • Recently the problems related to the failure of the retaining wall structure has become great concern since the damage to the properties and human losses have occurred in the rainy season. However, a detail guideline on safety inspection and appropriate diagnosis on the retaining wall structure have not yet proposed and therefore, the inspection process and results are mainly dependant upon the engineers. The objective of this study is to propose objective and quantitative evaluation method for the condition based on the damage shapes and material types. In this purpose, composing materials of retaining wall are divided Into concrete, gabion, stone and reinforced earth, and then the evaluation items and method are suggested on the basis of the materials and structural characteristics of the retaining wall.

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Neuropsychiatric Aspect of Traumatic Brain Injury (두부외상의 신경정신과적 관점)

  • Kim, Young Chul
    • Korean Journal of Biological Psychiatry
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    • v.2 no.2
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    • pp.157-168
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    • 1995
  • The neuropsychiatric sequelae of traumatic brain unjury(TBI) are effects on complex aspect of behavior, cognition and emotional expression. They include psychiatric disorders such as depression, psychosis, personality change, dementia, and postconcussion syndrome. The damage is done not only to the cortex of the brain but also to subcortical and axial structures. The diffuse degeneration of cerebral white mailer is axonal damage that is caused by mechanical forces shearing the neuronal fiber at the moment of impact(diffuse axonal injury, DAI). The DAI and the changed receptor-agonist mechanism ore the most important mechanisms in genesis of neuropsychiatric sequalae by mild TBI. The most important instrument for diagnosis of neuropsychiatric sequalae of TBI is a physician or psychiatrist with experience and knowledge. The most effective therapeutic tool is a professional who understands the nature of the problem.

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