• Title/Summary/Keyword: 구조 안전 진단

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Disease, Accident and Health Behavior of in Farmers and Fishermen (농림어업인의 상병실태 및 건강행태 분석)

  • Kim, Kyung-Ran;Choi, Jeong-Wha
    • Journal of agricultural medicine and community health
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    • v.30 no.3
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    • pp.279-292
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    • 2005
  • Objectives: The purpose of this study is to analyze agricultural accident and disease using statistical data and materials about National Survey for Health & Nutrition in 2001 and to provide fundamental materials for studies about farmers' health and safety, decision of priority about research and policy. Results: Diagnosed chronic disease prevalence is 72.4% in farmer/fisher group, 49.8% in non farmer/fisher group. The chronic disease prevalence of musculoskeletal disease, circulatory disease, and gastroenteric disease is 46.5%, 18.2%, and 17.9% in farmer/fisher group respectively. The prevalence of musculoskeletal disease in farmer/fisher is 2.4 times higher than non farmer/fisher. This result shows that it need to evaluation for risk factors of musculoskeletal disease preferentially. Lifetime accident/poisoning rate is 18.2% In farmer/fisher group and 13.3% in non farmer/fisher group. The types of accidents were fracture>sprain>contusion and the reasons of accidents were traffic accident>falling/sliding. Conclusions: "Bad or very bad" response of farmer/fisher is almost 2 times higher than non farmer/fisher group. The rate of smoking and no exercising in farmer/fisher group is higher than non farmer/fisher group.

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A Study on the Stainability and DNA Conservation of Tissue Slides according to Fixation Time and Temperature (고정시간과 온도에 따른 조직 슬라이드의 염색성 및 DNA 보존성 연구)

  • Da-som JEONG
    • Korean Journal of Clinical Laboratory Science
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    • v.56 no.3
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    • pp.217-227
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    • 2024
  • In this paper, the factors affecting tissues during fixation on slides were determined by changing the tissue type, fixation time, and temperature. Also, stainability and DNA conservation were evaluated. The tissues selected were parenchymal and intestinal tissue. The stainability was evaluated using hematoxylin and eosin staining and a special stain suitable for the tissue. DNA conservation was evaluated using the DNA integrity number (DIN) for stability evaluation after purity measurement. The results showed that, at all temperatures, as time increased, there was no histomorphological difference and the stainability tended to intensify. The intestinal tissue tended to have less mucosal change and proper muscle layer degeneration. There was little difference in the purity. However, the longer the fixation time, the lower the DIN value for DNA. Significant differences were identified at 25℃ and 50℃. This means that fixation at 4℃ is the more safe for DNA. This experiment confirmed that, between the time and temperature conditions associated with fixation, time had a greater effect on both staining and DNA conservation. The results of this study are expected to provide basic data for future research on the setting appropriate conditions for fixation for histopathological examinations or diagnoses.

Correlation Analysis between Damage of Expansion Joints and Response of Deck in RC Slab Bridges (RC 슬래브교의 신축이음 손상과 바닥판 응답과의 상관관계 분석)

  • Jung, Hyun-Jin;An, Hyo-Joon;Park, Ki-Tae;Jung, Kyu-San;Kim, Yu-Hee;Lee, Jong-Han
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.25 no.6
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    • pp.245-253
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    • 2021
  • RC slab bridges account for the largest portion of deteriorated bridges in Korea. However, most RC slabs are not included in the first and second classes of bridges, which are subject to bridge safety management and maintenance. The highest damaged components in highway bridges are the subsidiary facilities including expansion joints and bearings. In particular, leakage through expansion joints causes deterioration and cracks of concrete and exposure of reinforced bars. Therefore, this study analyzed the effect of adhesion damage at expansion joints on the response of the deck in RC slab bridges. When the spacing between the expansion joints at both ends was closely adhered, cracks occurred in the concrete at both ends of the deck due to the resistance rigidity at the expansion joints. Based on the response results, the correlation analysis between displacements in the longitudinal direction of the expansion joint and concrete stress at both ends of the deck for each damage scenario was performed to investigate the effect of the occurrence of damage on the bridge behavior. When expansion joint devices at both sides were damaged, the correlation between displacement and stress showed a low correlation of 0.18 when the vehicles proceeded along all the lanes. Compared with those in the intact state, the deflections of the deck in the damaged case at both sides showed a low correlation of 0.34 to 0.53 while the vehicle passed and 0.17 to 0.43 after the vehicle passed. This means that the occurrence of cracks in the ends of concrete changed the behavior of the deck. Therefore, data-deriven damage detection could be developed to manage the damage to expansion joints that cause damage and deterioration of the deck.

Development Strengths of High Strength Headed Bars of RC and SFRC Exterior Beam-Column Joint (RC 및 SFRC 외부 보-기둥 접합부에 대한 고강도 확대머리 철근의 정착강도)

  • Duck-Young Jang;Jae-Won Jeong;Kang-Seok Lee;Seung-Hun Kim
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.27 no.6
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    • pp.94-101
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    • 2023
  • In this study, the development performance of the head bars, which is SD700, was experimentally evaluated at the RC (reinforced concrete) or SFRC (steel fiber reinforced concrete external beam-column joint. A total of 10 specimens were tested, and variables such as steel fibers, length of settlement, effective depth of the beam, and stirrups of the column were planned. As a result of the experiment, the specimens showed side-face blowout, concrete breakout, and shear failure depending on the experimental variables. In the RC series experiments with development length as a variable, it was confirmed that the development strength increased by 26.5~42.2% as the development length increased by 25-80%, which was not proportional to the development length. JD-based experiments with twice the effective depth of beams showed concrete breakout failure, reducing the maximum strength by 31.5% to 62% compared to the reference experiment. The S-series experiment, in which the spacing of the shear reinforcement around the enlarged head reinforcement was 1/2 times that of the reference experiment, increased the maximum strength by 8.4 to 9.7%. The concrete compressive strength of SFRC was evaluated to be 29.3% smaller than the concrete compressive strength of RC, but the development strength of SFRC specimens increased by 7.3% to 12.2%. Accordingly it was confirmed that the development performance of the head bar was greatly improved by reinforcing the steel fiber. Considering the results of 92% and 99% of the experimental maximum strength of the experiment arranged with 92% and 110% of the KDS-based settlement length, it is judged that the safety rate needs to be considered even more. In addition, it is required to present a design formula that considers the effective depth of the beam compared to the development length.

Review on Prior Evaluation for Terrorism Risk of High-rise Buildings (초고층건축물의 테러 위험도 사전평가에 관한 연구)

  • Seong, Bin;Lee, Yoon-Ho
    • Korean Security Journal
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    • no.36
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    • pp.293-316
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    • 2013
  • Today's high-rise buildings are increasing concern about the safety and evacuation of people related to the fire and threat from outside. Terrorism breaking out in high-rise buildings, a symbol of the national economy results in a number of casualties, economic loss, social fear and damage to national status. That's why high-rise building has also emerged as a target of major terrorist attacks, compared to other types of buildings. We have 54 high-rise buildings in 15 regions over the country. The Ministry of Land, Infrastructure and Transport and Seoul Metropolitan Government have offered the guidelines to prevent terrorist attacks toward high-rise buildings. Since the 9/11 terrorist attacks, the U.S. Federal Emergency Management Agency (FEMA) has developed and taken advantage of the Risk Management Manual Series. According to this manual, pre-assessment is conducted for the prevention of terrorism and particularly in FEMA 455, risk of the surrounding areas, vulnerability, possibility from terrorist attacks are checked. After the check, experts classify the risk of terrorist attacks toward the high-rise buildings and according to the risk classification, architects, security experts and structure engineers can carry out terrorism prevention program for high-rise buildings. The U.K. NaCTSO has also offered the terrorism prevention guidelines. Therefore, the Ministry of Land, Infrastructure and Transport and Seoul Metropolitan Government should make more concrete guidelines for high-rise buildings such as what U.S. FEMA and U.K. NaCTSO implement, including prior evaluation technique for terrorism risk.

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Experimental Study on Effect of Slope and Length of Apron on Discharge through Gate Structure (물받이 길이 및 접근경사에 따른 조력발전 배수구조물 통수능 검토 실험 연구)

  • Yoon, Kwang-Seok;Yeo, Kyu-Dong
    • Proceedings of the Korea Water Resources Association Conference
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    • 2005.05b
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    • pp.1026-1030
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    • 2005
  • 조력발전 건설사업에서 우선적으로 고려되어야 할 사항은 조수간만에 의해 외해부와 조지부 사이를 이동하는 해수를 적절히 소통시키는 것이다. 예를 들어, 단조지 단류식 발전으로 창조시에 발전을 행할 경우, 발전을 행하면서 높아진 조지내의 수위를 다음 발전을 위해서 낮아진 외해수위를 이용하여 효과적으로 배수시키지 못하면 그 시설은 발전효율이 낮아지게 된다. 즉, 수문구조물의 목적은 주어진 조건 하에서 계획된 유량을 충분히 그리고 안전하게 배제시키는 것이다. 본 연구에서는 수문구조물에 대한 물받이의 길이와 경사의 변화에 의한 외해 조위와 시화호 수위차 조건에 따른 유량계수를 구해 배수능력을 검토하고자 하였다. 이를 위해 시화호를 실험대상으로 하여 수리모형을 1:25의 축척비로 제작하였다. 시화방조제를 기준으로 외해부의 조위와 조지부의 수위차를 8가지의 실험조건으로 한 연구를 수행하였다. 유량계수를 산정하기 위하여 8개 실험조건을 계획에서 제시된 수위-조위 조건에서 수위차 및 통수유량을 분배하여 결정하였고, 유량계수 산정식에 따라 상류 흐름 안정지점에서 유속-면적법에 의해서 유량을 측정하였다. 유속은 8개 지점에 대해서 측정하였고, 각 측정지점에서의 측선은 $3\~5$개이며, 측점은 $3\~4$점법으로 수행하였다. 시화호와 외해의 수위차가 1.011m일 때의 수문을 통과하는 유량을 비교한 결과 실험 II와 III의 통과유량은 각각 $1,571m^3/s$$1,515m^3/s$ 의서 실험 I 의 $587m^3/s$에 비해 통수능이 많이 개선되었음을 알 수 있다. 그림 1은 수위차별 유량곡선을 나타내는 것으로, 실험 II에서의 수문의 통수능이 실험 I의 통수능보다 크게 나타남을 알 수 있었다.>일 때가 밸브를 $60\%$$80\%$ 개폐시켰을 때보다 $0.3kg/cm^2,\;0.29kg/cm^2$ 낮게 나타나 밸브를 전체 개방 했을 때 관로내의 수압이 상수설계기준에 적합한 수압을 유지함을 알 수 있다. 상수관로 설계 기준에서는 관로내 수압을 $1.5\~4.0kg/cm^2$으로 나타내고 있는데 $6kg/cm^2$보다 과수압을 나타내는 경우가 $100\%$로 밸브를 개방하였을 때보다 $60\%,\;80\%$ 개방하였을 때가 더 빈번히 발생하고 있으므로 대상지역의 밸브 개폐는 $100\%$ 개방하는 것이 선계기준에 적합한 것으로 나타났다. 밸브 개폐에 따른 수압 변화를 모의한 결과 밸브 개폐도를 적절히 유지하여 필요수량의 확보 및 누수방지대책에 활용할 수 있을 것으로 판단된다.8R(mm)(r^2=0.84)$로 지수적으로 증가하는 경향을 나타내었다. 유거수량은 토성별로 양토를 1.0으로 기준할 때 사양토가 0.86으로 가장 작았고, 식양토 1.09, 식토 1.15로 평가되어 침투수에 비해 토성별 차이가 크게 나타났다. 이는 토성이 세립질일 수록 유거수의 저항이 작기 때문으로 생각된다. 경사에 따라서는 경사도가 증가할수록 증가하였으며 $10\% 경사일 때를 기준으로 $Ro(mm)=Ro_{10}{\times}0.797{\times}e^{-0.021s(\%)}$로 나타났다.천성 승모판 폐쇄 부전등을 초래하는 심각한 선천성 심질환이다. 그러나 진단 즉시 직접 좌관상동맥-대동맥 이식술로 수술적 교정을 해줌으로써 좋은 성적을 기대할 수 있음을 보여주었다.특히 교사들이 중요하게 인식하는 해방적

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Core Technologies Derivation of Fusion DEMO Reactor Applying TRL and AHP (TRL과 AHP를 적용한 핵융합 실증로 핵심기술 도출)

  • CHANG, Hansoo;KIM, Youbean;CHOI, Wonjae;THO, Hyunsoo
    • Journal of Technology Innovation
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    • v.22 no.4
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    • pp.145-164
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    • 2014
  • Nuclear fusion is one of the most promising options for generating large amounts of carbon-free energy in the future. Major countries such as China, EU, and Japan have established a national plan for DEMO construction and they are implementing it. Korea has started a nuclear fusion research and development by the KSTAR project started in 1995. There are matured needs for a full-scale research and development initiatives to ensure competition with the major countries for DEMO as well as achieve the final goal to commercialize fusion energy. In this paper, we apply the TRL and AHP methods in order to identify the key technologies to conduct DEMO R&D. We propose the priorities of future R&D on DEMO by deriving a core technology in the field. At first, we review the scientific theory of fusion and trend of progress of DEMO activities in major countries. For previous studies, we review TRL and AHP methods to examine the technology classification system of DEMO and identify key technologies. We apply TRL method to identify readiness level of DEMO technologies and AHP to compensate shortcoming of TRL. The key technologies of DEMO to be secured from a synthesis result of the TRL and AHP are burning plasma, plasma facing material, structural material, high frequency heating, neutral particle beam, safety, plasma diagnostic, and simulation technologies.

Development of Alignment Information Extraction System on Highway by Terrestrial Laser Scanning Technique (지상 레이저 스캐닝 기법에 의한 도로선형정보 추출 시스템 개발)

  • Kim, Jin-Soo
    • Journal of the Korean Association of Geographic Information Studies
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    • v.10 no.4
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    • pp.97-110
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    • 2007
  • A laser scanning technique has been attracting much attention as a new technology to acquire location information. This technique might be applicable to a wide range of areas, most notably in geomatics, due to its high accuracy of location and automation of high-density data acquisition. A alignment information extraction system on highway has been developed in this study by utilizing the advantages of the laser scanning technique. The system can accurately interpret the alignment information of highway and can be applied to actual works. To develop the alignment information extraction system on highway, an algorithm that can automatically separate a horizontal alignment into a straight line, a transition curve, and a circular curve was developed. It can increase its efficiency compared to the conventional methods. In addition, an algorithm that can automatically extract design elements of horizontal and vertical alignments of highway was developed and applied to an object highway. This yielded higher practicality with more accurate values compared to those from previous studies on the extraction of design elements of highway alignment. Furthermore, the extracted design elements were used to perform a virtual driving simulation on the object highway. Through this, data were provided for a visual judgment for judging visually whether the topography and structures were harmonized in a three-dimensional manner or not. The study also presents data that can serve as a basis to determine highway surface freezing sections and to analyze three-dimensional sight distance models. Through the establishment of a systematic database for diverse data on highway and the development of web-based operating programs, an efficient highway maintenance can be ensured and also they can provide important information to be used when estimating a highway safety in the future.

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Changes of Hysteresis Loop Characteristics of the Tendon Under Tensile Stress (Tendon의 인장응력에 따른 자기이력특성 변화의 측정)

  • Kang, Sunju;Son, Derac;Joh, Changbin;Lee, Jungwoo
    • Journal of the Korean Magnetics Society
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    • v.25 no.4
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    • pp.123-128
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    • 2015
  • The iron is an element having a high yield strength, mechanical hardness, good electrical conductivity, and also it has been used in various fields because of ease machining. In bridges have been used tendon made of a steel wire for large loads and light weight. Tension measurement of tendon employed in PreStressed Concrete (PSC) bridge is very important for the bridge safety check. NDT (Non-Destructive Testing) is essential for the safety check, however, magnetic NDT is difficult to apply due to the non-linear magnetization curve and hysteresis loop in the magnetic properties. In this work, for basic study of magnetic NDT application, we have constructed a B-H loop measuring system for 7-strand tendon of which diameter is 15.5 mm, and which can apply tensile stress up to 2.0 GPa. We have measured hysteresis loops of two kinds of tendons under different tensile stress. Amplitude permeability and maximum magnetic induction near knee show the most sensitive and high linearity depends on tensile stress. Relative amplitude permeability was decreased from 500 to 200 and maximum magnetic flux density changed 0.6 T.

Preference Analysis on the Reconstruction and Remodeling of Old Aged Apartment in Daejeon Area (대전지역 노후화된 아파트의 재건축과 리모델링에 대한 선호도 분석)

  • Park, Sun-Gyu
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.4 no.2
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    • pp.180-186
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    • 2016
  • There are many apartment buildings with the government's policy of increasing the supply of residential houses in Korea. Roughly 60% of the Korea population are living in apartment buildings. Since the 1970s, the Korean economy has grown enormously, the economic and social structure was radically transformed to industrialization and urbanization step. A village has grown into a large town in Korea and apartment buildings was constructed to solve national housing shortage by the Korean government and the construction company. Since the 2000s, this apartment buildings which was built in the 1970s and 1980s had become gradually deteriorated. So, reconstruction and remodeling project of apartment buildings have been come into request in Korea. There are two way to improve the residential environment. The one is remodeling of apartment buildings and the other is reconstruction of that. Therefore, we carried out questionnaire and survey study of the preference on the reconstruction and remodeling of old aged apartment which were located in daejeon province. As a result, the preference rate of remodeling is increasing instead of reconstruction because reconstruction of apartment buildings takes more money and needs long construction period.