• Title/Summary/Keyword: construction operation management

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Development of a Failure Probability Model based on Operation Data of Thermal Piping Network in District Heating System (지역난방 열배관망 운영데이터 기반의 파손확률 모델 개발)

  • Kim, Hyoung Seok;Kim, Gye Beom;Kim, Lae Hyun
    • Korean Chemical Engineering Research
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    • v.55 no.3
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    • pp.322-331
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    • 2017
  • District heating was first introduced in Korea in 1985. As the service life of the underground thermal piping network has increased for more than 30 years, the maintenance of the underground thermal pipe has become an important issue. A variety of complex technologies are required for periodic inspection and operation management for the maintenance of the aged thermal piping network. Especially, it is required to develop a model that can be used for decision making in order to derive optimal maintenance and replacement point from the economic viewpoint in the field. In this study, the analysis was carried out based on the repair history and accident data at the operation of the thermal pipe network of five districts in the Korea District Heating Corporation. A failure probability model was developed by introducing statistical techniques of qualitative analysis and binomial logistic regression analysis. As a result of qualitative analysis of maintenance history and accident data, the most important cause of pipeline damage was construction erosion, corrosion of pipe and bad material accounted for about 82%. In the statistical model analysis, by setting the separation point of the classification to 0.25, the accuracy of the thermal pipe breakage and non-breakage classification improved to 73.5%. In order to establish the failure probability model, the fitness of the model was verified through the Hosmer and Lemeshow test, the independent test of the independent variables, and the Chi-Square test of the model. According to the results of analysis of the risk of thermal pipe network damage, the highest probability of failure was analyzed as the thermal pipeline constructed by the F construction company in the reducer pipe of less than 250mm, which is more than 10 years on the Seoul area motorway in winter. The results of this study can be used to prioritize maintenance, preventive inspection, and replacement of thermal piping systems. In addition, it will be possible to reduce the frequency of thermal pipeline damage and to use it more aggressively to manage thermal piping network by establishing and coping with accident prevention plan in advance such as inspection and maintenance.

Study of the Value of National Cultural Heritage in the Gaetaesa Temple Site, Nonsan and the Establishment of an Integrated Maintenance Plan (논산 개태사지의 국가문화재적 가치 및 종합정비방안 수립에 관한 연구)

  • Seo, Jung-young
    • Journal of the Korean Institute of Landscape Architecture
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    • v.47 no.2
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    • pp.76-87
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    • 2019
  • This study aims to analyze the status of the Gaetaesa Temple Site in Nonsan and the value of national cultural heritage associated with it, to work towards gaining the acceptance criteria to become state-designated cultural property and to propose a plan for comprehensive maintenance, a plan for the promotion of the project and a plan for the management and operation. The Gaetaesa Temple Site in Nonsan has unprecedented advancements, and the condition of the remains are relatively good. It would be necessary to conduct digging/excavation surveys continuously in the future and ensure the dignity of the Gaetaesa Temple Site in Nonsan as a cultural asset. In addition, the Gaetaesa Temple Site has excellent historical and cultural values as treasure-class cultural heritage. Most temples had treasures taken out of them, so it is necessary to designate this site as a state-designated cultural property instead of a municipality-designated cultural heritage site, and to manage it systematically. Accordingly, this study investigated the history and historical facts about the Gaetaesa Temple Site in Nonsan through the analysis of literature, including old documents, old maps, related academic papers and books, and referred to the results of digging/excavation surveys, conducted up to six times since the first excavation survey conducted in 1986, in order to understand the status of the remains, ruins and the building sites excavated at the Gaetaesa Temple Site in Nonsan. In addition, this study analyzed the values of the Gaetaesa Temple Site in Nonsan, dividing them into the remains, relics and ruins, and set up the scope of the Gaetaesa Temple Site in Nonsan, the cultural property area (designated and protected areas) and the acceptance criteria for the construction work in the historical and cultural environment preservation area. This study proposed a plan for the comprehensive maintenance of the Gaetaesa Temple Site in Nonsan, a plan for the promotion of the project and a plan for the management and operation. It is necessary to carry out ongoing excavation investigations and to reflect the opinions of the residents for the purchase of land, to supplement the comprehensive maintenance plan, business promotion and management plans, and step-by-step business plans should be established in detail.

A Study on the Use of Scientific Investigation Equipment to Support Decision-making of the Resident Evacuation in the Event of a Chemical Accident (화학사고 발생에 따른 주민대피 의사결정 지원을 위한 과학조사장비 활용방안 연구)

  • Oh, Joo-Yeon;Lee, Tae Wook;Cho, Kuk
    • Korean Journal of Remote Sensing
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    • v.38 no.6_3
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    • pp.1817-1826
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    • 2022
  • After the hydrogen fluoride leak in Gumi in 2012, the government has been systemizing the disaster management system, such as responding to and managing chemical accidents. In particular, the Ministry of the Interior and Safety (MOIS) is in charge of evacuation of residents following chemical accidents based on the Framework Act on Management of Disaster and Safety. In this study, an application plan was presented to support and utilize the decision-making support for evacuation of residents after a chemical accident using the chemical accident investigation equipment of the National Disaster Management Research Institute (NDMI). In the equipment operation system for scientific information collection due to chemical accidents, the roles and purpose of use of long/short distance measurement equipment were presented according to regular and emergency situations. Using the data acquired through long/short distance measurement equipment, it can be used as basic data for resident evacuation decision-making by monitoring whether chemicals are detected in an emergency and managing data on detected substances by company in a regular situation. As a result of measuring chemical substances in order to verify on-site usability by equipment only for the regular operation system, it was confirmed that real-time detection of chemical substances is possible with long distance measuring equipment. In addition, it was confirmed that it was necessary to check the measurable distance and range of the equipment in the future. In the case of short distance measurement equipment, hydrocarbon-based substances were mainly detected, and it was confirmed that it was measured at a higher level in Ulsan-Mipo National Industrial Complex than in Onsan National Industrial Complex. It is expected that it can be used as basic data to support decision-making in the event of chemical accidents through continuous data construction in the future.

Efficiently Development Plan from the User's Need Analysis of the Army Tactical C4I(ATCIS) System (지상전술 C4I(ATCIS)체계 운용자 요구분석을 통한 효율적 발전 방안)

  • Park, Chang-Woon;Yang, Hae-Sool
    • The Journal of the Korea Contents Association
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    • v.8 no.5
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    • pp.246-259
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    • 2008
  • This study was to minimize the trial and error in the primary step of the C4I system(ATCIS) of the each army corps on the front line, and test the economy and efficiency was tested by reviewing related papers and the system characteristics of other countries. The relationship was researched by analyzing the collected survey data and survey data related to the user's requirement level such as the army standards, that is, commonality, timeliness, simplification, automaticity, field availability and viability, multi-stage security and interoperability, unification. The result showed that the C4I system was efficiently operated through the system reliability for the specification of the system and operation manual, maneuverability and security, adaptability of the war field and system support and management, and good education and training about system operation, and less system maintenance and supplementary element. As a result, the development plan confirmed that the continuous operator education and the construction of the maintenance, and the upgrade digitalization(C4ISR+D) with the korean characteristics based on IT of network systems, and system development of the measurement model of the operator performance must be continuously supplemented in the near future.

Case Study on the Improvement of Pollutant Removal Efficiency in Sihwa Constructed Wetland (시화호 인공습지의 수질정화기능 향상을 위한 사례연구)

  • Choi, Don-Hyeok;Kang, Ho;Choi, Kwang-Soon
    • Journal of Wetlands Research
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    • v.12 no.2
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    • pp.25-33
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    • 2010
  • Three plans(induction of water flow, supply of oxygen into water, control of fish causing resuspension of solids) proposed to improve the pollutant removal efficiency of Sihwa Constructed Wetland(CW) were estimated by considering the their efficiency and application to the wetland. After construction of facility for induction of water flow in lower part(W 122m${\times}$L 103m) of the wetland, the mean removal efficiencies of BOD, SS, TN and TP were in range of 12.8~37.4% and BOD was showing the highest efficiency. This result indicates that water flows is one of very important factors in the pollutant removal of wetland, especially near the outlet of a large scale wetland such as Sihwa CW. Dissolved oxygen(DO) concentrations after operation of two oxygen supply systems such as Air Bubble Diffuser and Surface Aeration System increased 15.5% and 27.2%, respectively. For maintaining effective DO concentration in Sihwa CW, the operation of oxygen supply system may be desirable during midnight to dawn in the location in which DO concentration is not enough, for instance less than 2 mg/L in CW. In experiments of the fish removal from Sihwa CW, the mean turbidity was lower in test site(6.2 NTU) than control site(10.6). The removal efficiency of thurbidity by th fish removal from the wetland was 41.5%. Therefore, a relevant fish management through a periodical monitoring of fish and turbidity is needed.

Model Predictive Control for Distributed Storage Facilities and Sewer Network Systems via PSO (분산형 저류시설-하수관망 네트워크 시스템의 입자군집최적화 기반 모델 예측 제어)

  • Baek, Hyunwook;Ryu, Jaena;Kim, Tea-Hyoung;Oh, Jeill
    • Journal of the Korean Institute of Intelligent Systems
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    • v.22 no.6
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    • pp.722-728
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    • 2012
  • Urban sewer systems has a limitation of capacity of rainwater storage and problem of occurrence of untreated sewage, so adopting a storage facility for sewer flooding prevention and urban non-point pollution reduction has a big attention. The Korea Ministry of Environment has recently introduced a new concept of "multi-functional storage facility", which is crucial not only in preventive stormwater management but also in dealing with combined sewer overflow and sanitary sewer discharge, and also has been promoting its adoption. However, reserving a space for a single large-scale storage facility might be difficult especially in urban areas. Thus, decentralized construction of small- and midium-sized storage facilities and its operation have been introduced as an alternative way. In this paper, we propose a model predictive control scheme for an optimized operation of distributed storage facilities and sewer networks. To this aim, we first describe the mathematical model of each component of networks system which enables us to analyze its detailed dynamic behavior. Second, overflow locations and volumes will be predicted based on the developed network model with data on the external inflow occurred at specific locations of the network. MPC scheme based on the introduced particle swarm optimization technique then produces the optimized the gate setting for sewer network flow control, which minimizes sewer flooding and maximizes the potential storage capacity. Finally, the operational efficacy of the proposed control scheme is demonstrated by simulation study with virtual rainstorm event.

A Study on the Improvement Plan of the Safety Certification System through the Typology of the Actual Condition Survey Results (실태조사 결과의 유형화를 통한 안전인증제도 개선방안 연구)

  • Byeon, Junghwan;Kim, Jung-Gon
    • Journal of the Society of Disaster Information
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    • v.17 no.2
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    • pp.391-402
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    • 2021
  • Purpose: By categorizing opinions by subject in the safety certification ecosystem, we want to identify weaknesses in system operation and suggest improvement plans so that the safety certification system can have quick resilience against future variability. Method: Through literature research and data analysis, similar domestic and foreign safety certifications and related cases, as well as the current status of international standards and national standards, etc. were confirmed, and a fact-finding survey was conducted for each stakeholder in the safety certification ecosystem, and problem types and improvement measures were established. Result: We conduct a fact-finding survey of the overall system, such as quality satisfaction with safety certification target products, obstacles in the development, manufacturing and use process, and safety certification-related improvements, targeting workplaces that manufacture, import or use safety certification target machines By discovering and categorizing problems and weaknesses in system operation, detailed implementation tasks were derived to establish improvement directions and improve operability. Conclusion: For the advancement and internationalization of the safety certification system, it is necessary to efficiently carry out the detailed promotion tasks derived from this study. In addition, in order to strengthen the resilience to the variability of the safety certification ecosystem, the operating system of a virtuous cycle structure by improving the mutual relationship between each subject construction is considered important.

A Study on the Performance Evaluation Measures of Traffic Signal Operation at Signalized Intersections by Utilizing Historical Data from Advanced Traveller Information System (첨단 교통 정보 시스템 누적 소통정보를 활용한 신호교차로 운영개선 효과평가를 위한 혼잡강도 지표 연구)

  • Cho, Yong-bin;Kim, Jin-tae
    • The Journal of the Korea Contents Association
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    • v.18 no.11
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    • pp.643-654
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    • 2018
  • In order to understand and manage traffic flows in urban areas in the past, a variety of traffic engineering theoretical indicators such as intersection lag and highway speed have been applied. However, these theories and indicators have been developed under the constraints of traffic engineering research before the construction of intelligent transportation system. Since the ATIS system currently exists, it is necessary to introduce a separate traffic engineering technology that utilizes the data. In this paper, it is aimed to confirm whether it is applicable to intermittent flow (approach road, intersection, control group, main road axis) by using 'congestion intensity' which is already used in traffic engineering field. The results of this study are as follows: (1) The traffic signal improvement effect of urban road access road, intersection road, control group, Two verification studies were performed to verify the derived congestion intensity index. (1) verification of congestion intensity threshold value analysis and (2) crossing improvement using the congestion intensity. Through verification, it was confirmed that it is possible to apply the congestion intensity in the inter - city intermittent flow using the 5 - minute unit speed data so as to be able to escape from the existing traffic signal operation management which is past passive and manpower limit.

Bleeding control of an injury to the infrarenal inferior vena cava and right external iliac vein by ipsilateral internal iliac artery and superficial femoral vein ligation after blunt abdominal trauma in Korea: a case report

  • Hoonsung Park;Maru Kim;Dae-Sang Lee;Tae Hwa Hong;Doo-Hun Kim;Hangjoo Cho
    • Journal of Trauma and Injury
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    • v.36 no.4
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    • pp.441-446
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    • 2023
  • Inferior vena cava (IVC) injuries, while accounting for fewer than 0.5% of blunt abdominal trauma cases, are among the most difficult to manage. Despite advancements in prehospital care, transportation, operative techniques, and perioperative management, the mortality rate for IVC injuries has remained at 20% to 66% for several decades. Furthermore, 30% to 50% of patients with IVC injuries succumb during the prehospital phase. A 65-year-old male patient, who had been struck in the back by a 500-kg excavator shovel at a construction site, was transported to a regional trauma center. Injuries to the right side of the infrarenal IVC and the right external iliac vein (EIV) were suspected, along with fractures to the right iliac bone and sacrum. The injury to the right side of the infrarenal IVC wall was repaired, and the right internal iliac artery was ligated. However, persistent bleeding around the right EIV was observed, and we were unable to achieve proximal and distal control of the right EIV. Attempts at prolonged manual compression were unsuccessful. To decrease venous return, we ligated the right superficial femoral vein. This reduced the amount of bleeding, enabling us to secure the surgical field. We ultimately controlled the bleeding, and approximately 5 L of blood products were infused intraoperatively. A second-look operation was performed 2 days later, by which time most of the bleeding sites had ceased. Orthopedic surgeons then took over the operation, performing closed reduction and external fixation. Five days later, the patient underwent definitive fixation and was transferred for rehabilitation on postoperative day 22.

Study on Customer Satisfaction Performance Evaluation through e-SCM-based OMS Implementation (e-SCM 기반 OMS 구현을 통한 고객 만족 성과평가에 관한 연구)

  • Hyungdo Zun;ChiGon Kim;KyungBae Yoon
    • The Journal of the Convergence on Culture Technology
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    • v.10 no.3
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    • pp.891-899
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    • 2024
  • The Fourth Industrial Revolution is centered on a personalized demand fulfillment economy and is all about transformation and flexible processing that can deliver what customers want in real time across space and time. This paper implements the construction and operation of a packaging platform that can instantly procure the required packaging products based on real-time orders and evaluates its performance. The components of customer satisfaction are flexible and dependent on the situation which requires efficient management of enterprise operational processes based on an e-SCM platform. An OMS optimized for these conditions plays an important role in maximizing and differentiating the efficiency of a company's operations and improving its cost advantage. OMS is a system of mass customization that provides efficient MOT(Moment of Truth) logistics services to meet the eco-friendly issues of many individual customers and achieve optimized logistics operation goals to enhance repurchase intentions and sustainable business. OMS precisely analyzes the collected data to support information and decision-making related to efficiency, productivity, cost and provide accurate reports. It uses data visualization tools to express data visually and suggests directions for improvement of the operational process through statistics and prediction analysis.