• Title/Summary/Keyword: Foundation inspection

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Fragility Assessment of Offshore Wind Turbine by Ship Collision (선박충돌에 의한 해상풍력발전기의 취약도 평가)

  • Cho, Byung Il;Kim, Dong Hyawn
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.25 no.4
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    • pp.236-243
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    • 2013
  • Offshore wind turbines has to be proved against accidental events such as ship collision. In this study, ship collision fragility analysis of offshore wind turbine is done. Dynamic collision analysis is accomplished by considering soil foundation interaction and fluid structure interaction. Uncertainties due to ship weight and speed, angle are also considered. By analyzing dynamic response of offshore wind turbine, fragility curves are obtained for different damage levels. They can be used for restricting boat speed around the wind turbine and allowable size of the boat for inspection and for other purposes. Results of the fragility, it was confirmed fragility of collision speed of bulk ship of 30,000DWT and 850ton barge ship.

Wireless structural health monitoring of bridges: present and future

  • Hoult, Neil A.;Fidler, Paul R.A.;Hill, Peter G.;Middleton, Campbell R.
    • Smart Structures and Systems
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    • v.6 no.3
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    • pp.277-290
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    • 2010
  • Internationally the load carrying capacity of bridges is decreasing due to material deterioration while at the same time increasing live loads mean that they are often exposed to stresses for which they were not designed. However there are limited resources available to ensure that these bridges are fit for purpose, meaning that new approaches to bridge maintenance are required that optimize both their service lives as well as maintenance costs. Wireless sensor networks (WSNs) provide a tool that could support such an optimized maintenance program. In many situations WSNs have advantages over conventional wired monitoring systems in terms of installation time and cost. In order to evaluate the potential of these systems two WSNs were installed starting in July 2007 on the Humber Bridge and on a nearby approach bridge. As part of a corrosion prevention strategy, a relative humidity and temperature monitoring system was installed in the north anchorage chambers of the main suspension bridge where the main cables of the bridge are anchored into the foundation. This system allows the Bridgemaster to check whether the maximum relative humidity threshold, above which corrosion of the steel wires might occur, is not crossed. A second WSN which monitors aspects of deterioration on a reinforced concrete bridge located on the approach to the main suspension bridge was also installed. Though both systems have provided useful data to the owners, there are still challenges that must be overcome in terms of monitoring corrosion of steel, measuring live loading and data management before WSNs can become an effective tool for bridge managers.

A study on legal improvement on Online P2P financial loan

  • Park, Jong-Ryeol;Noe, Sang-Ouk
    • Journal of the Korea Society of Computer and Information
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    • v.22 no.6
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    • pp.141-147
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    • 2017
  • Along with the recent growth of Fintech industry and low interest rate basis, one of the alternative investment technique for expecting higher investment profit, P2P loan using P2P financial system is greatly increasing. P2P loan can be referred to as a type of Crowdfunding that the law of Crowdfunding (adopted to revised Capital Market Act) enacted on January 25th 2016 only allows investment type Crowdfunding so that it can be used as a tool of raising fund for startup and venture companies. Also, it is true that Korean government could not make any legislative foundation related to P2P loan. At this moment, those online platform companies mediating P2P loan are not included as financial companies, expected to cause various legal arguments. Financial Services Commission has released a guideline in February of this year saying that limit of P2P loan is 10 million Korean Won per arbitrating company and 5 million Korean Won per borrower. However, what is more important is to make a law supporting this institutional system. If legislation on P2P loan is implemented without care, it may disturb growth of the field but it may result in the damage of investors if not clearly defined by law. As this is the case, first, "revision of execution regulations for loan business" should take place as soon as possible to intensify inspection of loan companies by registering them to Financial Services Commission. Second, saving customer fund separately in the their organization. Third, making law on protecting investors such as regulating exaggerative advertisement. Fourth, to have transparent and fair public announcement system, standardized agreement and guideline describing clear understanding on autonomous public information publication of P2P loan online platform business and information on the borrower.

Analysis of Cause of Excavator Safety Accidents according to the Accident Case Study (중대재해사례를 통한 굴삭기 안전사고 원인분석)

  • Seo, Jong-Min;Han, Kap-Kyu;Lim, Ji-Young;Kim, Sun-Kuk
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2007.11a
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    • pp.450-454
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    • 2007
  • In line with the construction projects, which have been increasingly getting larger and complex, safety accident has been on the rise, particularly those in association with the construction equipment. In a bid to prevent the safety accident, it's needed to analyze the cause of such accidents. The thesis was intended to identify the cause of safety accident by reviewing the cases of construction disaster complied by Korea Occupational Safety and Health Agency. The cases subject to study were limited to the accident by excavator. Summarizing the study is as follows. 1) Among the cause of accidents caused by excavator were, in order of high frequency, being caught in equipment or machine, falling, being crashed or bumped. 2) Among the causes of accident were, in order of high frequency, worker's unauthorized presence within the range of equipment operation. inappropriate use, failure of equipment inspection prior to starting work and inappropriate work method. The study is highly expected to pave the foundation for further study as well as to make commitment to mitigating the safety accident.

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Microbusinesses and Occupational Stress: Emotional Demands, Job Resources, and Depression Among Korean Immigrant Microbusiness Owners in Toronto, Canada

  • Kim, Il-Ho;Noh, Samuel;Choi, Cyu-Chul;McKenzie, Kwame
    • Journal of Preventive Medicine and Public Health
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    • v.52 no.5
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    • pp.299-307
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    • 2019
  • Objectives: While occupational stress has long been a central focus of psychological research, few studies have investigated how immigrant microbusiness owners (MBOs) respond to their unusually demanding occupation, or how their unresolved occupational stress manifests in psychological distress. Based on the job demands-resources model, this study compared MBOs to employees with regard to the relationships among emotional demands, job resources, and depressive symptoms. Methods: Data were derived from a cross-sectional survey of 1288 Korean immigrant workers (MBOs, professionals, office workers, and manual workers) aged 30 to 70, living in Toronto and surrounding areas. Face-to-face interviews were conducted between March 2013 and November 2013. Results: Among the four occupational groups, MBOs appeared to endure the greatest level of emotional demands, while reporting relatively lower levels of job satisfaction and job security; but MBOs reported the greatest job autonomy. The effect of emotional demands on depressive symptoms was greater for MBOs than for professionals. However, an inspection of stress-resource interactions indicated that though MBOs enjoyed the greatest autonomy, the protective effects of job satisfaction and security on the psychological risk of emotional demands appeared to be more pronounced for MBOs than for any of the employee groups. Conclusions: One in two Korean immigrants choose self-employment, most typically in family-owned microbusinesses that involve emotionally taxing dealings with clients and suppliers. However, the benefits of job satisfaction and security may protect MBOs from the adverse mental health effects of job stress.

An Analysis of the Social Phenomena and Perceptions of the Special Case of Military Service System in Korean Sports Field Using Big Data (빅데이터분석을 통한 체육계 병역특례제도의 사회적 현상 및 인식분석)

  • Lee, Hyun-Jeong;Han, Hae-Won
    • Journal of the Korea Convergence Society
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    • v.10 no.4
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    • pp.229-236
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    • 2019
  • The purpose of this paper is to analyze social phenomena and perceptions by collecting and analyzing data on public opinion, views and trends related to special case of military service in the sports community through Big KINDS operated by the Korea Press Promotion Foundation. To this end, the related keywords were derived and visualized by implementing a LDA(latent dirichlet allocation) technique to derive problems found in social phenomena based on big data analysis. The topics derived include "re-lighting special case on military service," " military service corruption controversy," "special case of military service for athletes," "alternative military service system for artists " and "parliamentary inspection of the administration" This could be used as a basic data for identifying accurate information on social controversies related to special case of military service in the sports community and drawing up practical measures that are considered in line with the principle of just and equal burden.

A Study on Bearing Capacity of Cast-In-Place Pre-Founded Columns in Top Down Construction Sites (Top Down 공사현장에 적용되는 현장타설 선기초기둥의 지지력에 관한 연구)

  • Byun, Yoseph;Jung, Kyoungsik;Kim, Jongho;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
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    • v.12 no.12
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    • pp.55-61
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    • 2011
  • Recently, a concept of the downtown area was progressively extended by improvement of rapid transportation system and development of the most advanced telecommunication industries. And underground has become bigger in addition deeper, Excavation methods which construct a structure were changed according to construction environments. Top Down methods which are continuous with architectural plan differ from existing excavation methods innovatively, pre-founded column is an important factor for construction methods, duration, expenses. Therefore, this study considers application by investigative methods according to comparison, analysis on loading test result of on site inspection and estimated results of bearing capacity for structure pre-founded column. As a result, almost designing eclipse appeared prior value which didn't arrive result of load test. Also, evaluate permanent load for the compressive stress acting on head of cast-in-place after basic structure was installed. Then, applying stress generally is reduced by confining effect with foundation.

Development of 2D Data Quality Validation Techniques for Pipe-type Underground Facilities (2차원 관로형 지하시설물 정보 품질검증기술 개발)

  • Sang-Keun Bae;Sang-Min Kim;Eun-Jin Yoo;Keo-Bae Lim;Da-Woon Jeong
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.46 no.3
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    • pp.285-292
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    • 2023
  • As various accidents have occurred in underground spaces, we aim to improve the quality validation standards and methods as specified in the Regulations on Producing Integrated Map of Underground Spaces devised by the Ministry of Land, Infrastructure and Transport of the Republic of Korea for a high-quality integrated map of underground spaces. Specifically, we propose measures to improve the quality assurance of pipeline-type underground facilities, the so-called life lines given their importance for citizens' daily activities and their highest risk of accident among the 16 types of underground facilities. After implementing quality validation software based on the developed quality validation standards, the adequacy of the validation standards was demonstrated by testing using data from two-dimensional water supply facilities in some areas of Busan, Korea. This paper has great significance in that it has laid the foundation for reducing the time and manpower required for data quality inspection and improving data quality reliability by improving current quality validation standards and developing technologies that can automatically extract errors through software.

Survey on Sexually Transmitted Infection Test of One Referral Laboratory in Seoul: Focused on Multiple Sexually Transmitted Diseases (서울 소재 일개 수탁 검사 기관에서 성병 검사의 실태조사: 다발성 성매개 감염병 중심으로)

  • Seok, Dong-In;Sung, Hyun Ho;Park, Chang-Eun
    • Korean Journal of Clinical Laboratory Science
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    • v.52 no.3
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    • pp.237-244
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    • 2020
  • Currently, sexually transmitted diseases (STD) are referred to as "sexually transmitted infections" (STIs) in the sense of including asymptomatic infections. STIs have a range of interrelationships. This study used the STI defined by the Minister of Health and Welfare of the Republic of Korea, and targeted syphilis, gonorrhea, chlamydia infection, chancroid, genital herpes simplex, condyloma, human papillomavirus, and non-gonococcal urethritis. The factors were characterized by identifying multiple and simultaneous STIs. This study used the data from the laboratory information system of a consigned inspection institution located in Seoul from 2014 to 2019. In this study, multiple STIs were identified as overlapping STIs of a double infectious source (10 types) and multiple STIs of a third infectious source (6 types). Among the 16 types of multiple STIs, U. urealyticum (9 types), HSV-2 (8 types), C. trachomatis (7 types), HPV 6, 11 (7 types), N. gonorrhoeae (6 types), and T. pallidum (1 type) were included. Therefore, additional research on interrelationship studies, such as STIs, which has the highest proportion of multiple STIs, will be necessary.

A Case Study of Underwater Blasting (수중발파 사례 연구)

  • 정민수;박종호;송영석
    • Explosives and Blasting
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    • v.22 no.3
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    • pp.57-64
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    • 2004
  • There are two major types of underwater blasting at Korea, bridges and harbor construction work. Pier blasting for lay the foundation bridges construction is used dry excavation working (drilling and charging) after pump out water and then fire pump in water that is same as bench blasting. In contrast, underwater blasting for harbor construction and increase of harbor load depth is used to barge with digging equipment that is in oder to drilling on the surface and blasting work(charge, hook-up) under water. Thus, there are need to special concern such as charge method and hook-up method different from tunnel blasting work and bench blasting work. If do not use special concern breaks out dead pressure and mis fire because of there are so many difficult condition such as water pressure, obstruct field of vision. In this study underwater blasting at Busan Harbor Construction have consider with special concern that is plastic pipe charge method used to MegaMITE I and specialized buoy hook- up method make far initial system detonate on the surface used to TLD. The results is designed blast pattern charge per delay effect an inspection of verify between predict velocity and measure velocity. minimized break out mis fire consideration charge method, hook up method. According to result best underwater blasting design is 105mm drilling dia, MeGAMITE II, HiNLL Plus(non electric detonator).