• Title/Summary/Keyword: investigation methods

Search Result 4,131, Processing Time 0.031 seconds

Field Investigation of Scour-Protection Methods for Bridges in Small Size Streams of Central Region of Korea (중부 지역 중.소하천 교량의 세굴보호공에 관한 조사연구)

  • Kim, Byoung-Il;Yoon, Ki-Yong;Lee, Seung-Hyun
    • Journal of the Korean Society of Hazard Mitigation
    • /
    • v.5 no.1 s.16
    • /
    • pp.45-53
    • /
    • 2005
  • Scour plays a principal role in maintaining stability and durability of bridges. Especially, in case of severe flood events, flow rate getting increase in a short time, scour can impede the functioning of bridges to the extent that they must be taken out of operation, and even can imperil their stability and structural integrity. In Korea, about 100 bridges were collapsed or damaged every you. Sufficient field investigation, however, was not made and, therefore, no adequate countermeasure for scouring is available. In this study, literature on scour-protection methods are reviewed and data on countermeasures of scouring which were collected through field investigation in central region of Korea are analyzed.

Preliminary Study on Effect of Baseline Correction in Acceleration Excitation Method on Finite Element Elastic-Plastic Time-History Seismic Analysis Results of Nuclear Safety Class I Components (원전 안전 1등급 기기의 유한요소 탄소성 시간이력 지진해석 결과에 미치는 가속도 가진 방법 내 기준선 조정의 영향에 대한 예비연구)

  • Kim, Jong-Sung;Park, Sang-Hyeok
    • Transactions of the Korean Society of Pressure Vessels and Piping
    • /
    • v.14 no.2
    • /
    • pp.69-76
    • /
    • 2018
  • The paper presents preliminary investigation results for the effect of the baseline correction in the acceleration excitation method on finite element seismic analysis results (such as accumulated equivalent plastic strain, equivalent plastic strain considering cyclic plasticity, von Mises effective stress, etc) of nuclear safety Class I components. For investigation, finite element elastic-plastic time-history seismic analysis is performed for a surge line including a pressurizer lower head, a pressurizer surge nozzle, a surge piping, and a hot leg surge nozzle using the Chaboche hardening model. Analysis is performed for various seismic loading methods such as acceleration excitation methods with and without the baseline correction, and a displacement excitation method. Comparing finite element analysis results, the effect of the baseline correction is investigated. As a result of the investigation, it is identified that finite element analysis results using the three methods do not show significant difference.

Cost-effective Investigation on Contaminated Land and Assessment of Measurement Uncertainty (오염토양의 효율적 조사기법과 측정불확도의 평가방법)

  • 이종천
    • Economic and Environmental Geology
    • /
    • v.37 no.1
    • /
    • pp.49-59
    • /
    • 2004
  • The concectration and distribution of contaminants obtained from a contaminated land investigation or an environmental geochemistry survey constitutes the basis of a decision-making process on environmental policies or of scientific researches. As the quality of data determines the reliability of the result, the investigation plan should be adjusted according to the purpose of the investigation. In general, the effort to improve the data quality had been focused mainly on the QA/QC procedures in laboratories. The rapid progress of analytical instrument has also contributed toward improving the analytical precision to a sacrificable degree. Nevertheless, in many cases, it is not the analytical precision that needs improvement for the better precision of overall measurement process: it is rather during the sampling process in the field that is responsible for the poor precision. To assess the data quality on a measured value, ISO recommends to provide information on "measurement uncertainty" along with the measured value. The measurement uncertainty in an environmental measurement context can be explained as the statistical number that expresses the degree of the uncertainty stemming from the sampling and analytical procedures. There is a cost involved in order to improve the precision of sampling and analytical methods so as to decrease the degree of measurement uncertainty. The economical point of compromise in an investigation planning can be achieved when the allowable degree of uncertainty has been set before-hand. The investigation can then be planned accordingly not to exceed the uncertainty limit. Furthermore, if the measurement uncertainty estimated from the preliminary investigation can be separated into sampling and analytical uncertainties, it can be used as a criterion where the resources for the investigation should be allotted cost-effectively to reinforce the weakest link of the whole investigation process. This paper aims to present a method of estimating the level of measurement uncertainty of a measured contamination concentration at a site used as an example and to show how the estimated uncertainty can be applied to serve the particular purpose of an investigation.

Incident Investigator's Perspectives on Incident Investigations Conducted in Korea Industry (한국 산업계에서 사고조사 수행 시 사고조사자의 관점에 관한 연구)

  • Kwon, Jae Beom;Kwon, Young Guk
    • Journal of the Korean Society of Safety
    • /
    • v.36 no.2
    • /
    • pp.58-67
    • /
    • 2021
  • Incident investigation is regarded as a means to improve safety performance. For the prevention of industrial accidents, measures such as providing safety education, enhancing management interest and participation, establishing a safety management system, and conducting inspection of the work site are necessary. In particular, accident investigation activities, which are an important element of safety management, help to prevent similar accidents, thereby minimizing damage and enhancing work safety. They are critical for understanding business-related incidents and the vulnerabilities and opportunities associated with them. Therefore, it is clear that accident investigation activities are important for accident prevention. The primary focus of many incident investigation processes is on identifying the cause of an event. While considerable research has been conducted on potential accident investigation tools there has been little research on including the views and experiences of practitioners in the accident investigation process. In this study, a questionnaire survey was conducted among safety managers in the domestic manufacturing/construction industry to understand the practice of accident investigation. The investigation pertained to companies' accident investigation systems, the competence of investigators, and the identification and recommendations of the cause of accidents. From the analysis results of accident investigations, investigators' competence, the difficulty level of investigations, and the root causes of accidents were identified from the viewpoint of the participants of the accident investigations. In particular, the development of standardized and simple accident investigation methods and their dissemination to companies were found to be necessary for activating the root cause of accidents. Based on this, it can be used as basic data for the development of root cause analysis investigation techniques that are easily applicable to organizations.

A study of the Investigation Offices' Planning Standard and Criteria of the Police Station - By Analyzing the Actual Situation Survey of the Prototypes - (경찰서 수사부서 표준설계 공간모형과 지침 연구 - 환경개선 시범사례 실태조사를 중심으로 -)

  • Cho, Hyeonmi
    • Korean Institute of Interior Design Journal
    • /
    • v.27 no.1
    • /
    • pp.140-155
    • /
    • 2018
  • In response to the development of IT technology in the 21st century and the advancement of the public human rights consciousness, it has become necessary to continuously evolve the office environments to support the changes of organizational structure and work methods of the police investigation departments. As a facility standard, continuous researches on standardized design space models and guidelines of the police investigation departments are needed. In respond to the organizational changes for the convenience of the working police investigators and the protection of the human rights of the visiting public, the environmental improvement projects for the office of the investigation department of the police stations are going on since 2014. In this study, analyzation and verification of the 3 cases of pilot projects for the improvement of police investigation departments would be done, based on the policy research project in 2014: 'the standard design direction of police officers for the protection of human rights and benefit of police investigation process.' The purpose of this study is, first of all, the actual situation survey for presenting the standard design space model and guidelines of investigation department of the police department. Secondly, the validation of the spatial model adequacy for for the past 3 years' case study of the police investigation department's environmental improvements by the application of standardized design space models and guidelines. The result of this study would be to enable the more effective police department investigation environment improvement policy by presenting the standard design space models and guidelines of the investigation departments of the police facilities.

Problems and Improvement Directions for Damage Investigation of Aquaculture Products from Natural Disaster (양식수산물 자연재해 피해조사의 문제점과 개선방향 연구)

  • Kang, Jong-Ho;Moon, Gun-Ho
    • The Journal of Fisheries Business Administration
    • /
    • v.50 no.3
    • /
    • pp.31-42
    • /
    • 2019
  • This study aims to determine problems of the damage investigation system of aquaculture products resulting from natural disaster and to deduce improvement plans for such problems. The main problems revealed from this study were as follows: 1) detailed damage investigation is carried out only by one particular organization, 2) for aquaculture insurance subscribers another detailed damage investigation is conducted to reveal the causes of natural disaster by a joint investigator team formed according to a different legislation with a different purpose, 3) damage investigation is usually suffered from lack of labor, budget and time due to the restriction of natural damage to a certain period of season leading to the absence of quick reaction capability for irresistible natural disasters, and 4) there are no specified procedures and protocols for deciphering causes of a natural demage. The improvement plans to find solutions for such problems are as follows: 1) for the investigation, the object, method and role of the investigation organization should be clarified by improving the present legislation, 2) investigation methods for determining the demage causes should be systematized by making a manual to minimize disputes, and 3) supports for the investigation organization should be institutionalized to guarantee sufficient budget and manpower. Under the present circumstance with continuous natural damages, smooth procedures of damage compensation would lead to the management stability of aquaculture farms.

A Study on the Korea's Disaster Cause Investigation System - Comparison and Analysis with Overseas Investigation Agency - (국내 재난원인조사 체계에 대한 고찰 - 국외 조사기구와의 비교·분석 -)

  • Kyung Su Lee;Yeon Ju Kim;Tai Hoon Kim
    • Journal of the Korean Society of Safety
    • /
    • v.38 no.2
    • /
    • pp.68-80
    • /
    • 2023
  • Cooperation between government agencies is important for disaster management, and a thorough and objective cause investigation is important to prevent the recurrence of similar disasters. In South Korea, individual laws are scattered by ministries according to the disaster type, and most are operated as non-permanent organizations that are employed when disasters occur. Although expertise is recognized for each disaster type, each government agency's operation method is different, so when a large-scale disaster involving multiple ministries occurs, there is a limit to the coordination of roles and integrated management between government agencies. In particular, whenever a large-scale complex disaster occurs, problems arise regarding the independence, professionalism, and fairness of the cause investigation. Therefore, to supplement this, reviewing the management methods and systems of disaster cause investigations in advanced countries is necessary. Thus, in this study, the organization status, manpower, organizational structure, and cause investigation work system of NTSB of the United States, JTSB of Japan, and SHK of Sweden are identified to improve the disaster cause investigation system in Korea and are compared and analyzed with Korea's GDCIG. Additionally, issues and problems for the advancement of Korea's disaster cause investigation system are considered and improvements are suggested.

Vertical Distribution of Seaweeds in the Rocky Shore Ecosystem in Geomundo, South Coast of Korea: Analyzing Strengths and Weaknesses Using a Survey Method (한국의 남해 거문도 암반조하대의 수심별 해조류의 분포: 조사기법에 따른 장·단점)

  • Jong Il Bai;Sung Il hwang;Sang Jo Han;Bong Jun Seong;Byeong Hyeon Jeon
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.57 no.3
    • /
    • pp.278-291
    • /
    • 2024
  • This study performed three research methods (destructive, non-destructive, and panoramic image analysis) to determine the most useful for identifying seaweed habitat characteristics. Panoramic images are suitable for understanding the overall seaweed distribution. The composition of the main dominant seaweed species showed a significant difference between the destructive and non-destructive methods using Quadrat. The destructive method showed Rhodophyta dominance, whereas the non-destructive was showed Phaeophyta as dominant. Destructive methods are disadvantageous because they destroy natural communities in sea areas where bleaching is severe. Non-destructive methods are disadvantageous because of the difficulty in analyzing small species. Performing 10 surveys using a non-destructive method was found to explain up to 80% of the species identified by the destructive method. However, considering the difficulty of field investigation, repeating the investigation with non-destructive methods at least 6-7 times is necessary to ensure that more than 60% of the destructive methods can be interpreted. To understand the distribution of oceanic marine algae, performing both destructive and non-destructive surveys are necessary, as each has its own merits and demerits.

Manipulation of Single Cell for Separation and Investigation

  • Arai, Fumihito;Ichikawa, Akihiko;Maruyama, Hisataka;Motoo, Kouhei;Fukuda, Toshio
    • International Journal of Control, Automation, and Systems
    • /
    • v.2 no.2
    • /
    • pp.135-143
    • /
    • 2004
  • Recently, high throughput screening for microorganisms with desired characteristics from a large heterogeneous population has become possible. Single cell separation has taken on increasing significance in recent years, and several different methods have been proposed so far. In this paper, we introduce several cell manipulation methods aiming at single cell separation and investigation. At first, methods for the separation of microorganisms are classified. Then, we introduce two different approaches, that is, (1) indirect manipulation using laser trapped microtools and (2) thermal gelation.

A Case Study of Analysis and Design for the Tunnel Stablization in Fault Zone by FRP Reinforced Grouting Method (FRP보강 그라우팅에 의한 단층대의 터널 안정성 분석 및 설계 사례 연구)

  • 박종호;최용기;박영목;권오엽;이재봉
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2001.03a
    • /
    • pp.121-128
    • /
    • 2001
  • This is a case study of stability analysis and reinforcement design for the tunnel where the collapse of the entrance slops occured along the fault zone developed in the bed rock. According to the site investigation, the main factor of sliding is the influence of fault gouge and heavy rainfall. Considering the in-situ condition, the versatile reinforcement methods is needed, and so the close investigation on the site area was accompanied with the stability analysis of tunnel and slops. The FRP(Fiberglass reinforced plastic) grouting method improved the defect of Steel Umbrella Arch Method, such as oxidation, low work efficiency, the material's heavy weight, is adapted as the reinforcement methods.

  • PDF