• Title/Summary/Keyword: 전기통신공사

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The Effectiveness of Accounting Information in Military Construction Contracts under the Qualification Assessment System (적격심사낙찰제 계약에서 회계정보의 유용성에 관한 연구)

  • Hur, Hyung
    • Journal of the military operations research society of Korea
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    • v.37 no.1
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    • pp.49-70
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    • 2011
  • This paper re-evaluated the research on the accounting information's effectiveness in military construction contracts, questioning the former research results on the central army's construction contract that was under the Qualification Assessment System, especially concerning the relations between the accounting information and the bidding ratios as well as the relations between the bidding rates and the defect rates, which targeted between 1 to 10 billions civil engineering, construction, electricity, telecommunication, and environment work types. Unlike the previous results, the relationship between the accounting information and the bidding rates was shown to be considerably limited that the bidding ratio could not be identified through the accounting information, while it could discern the relations with the defect rates. Furthermore, the proven results did not support the hypothesis that the differences in bidding rates could affect the defect ratio. However, through the prediction model of bidding and defect ratios, we could identity the accounting variables that influenced the ratios. Additionally through the results regarding the non-financial indexes in the Pre-Qualification items, the weight on these indexes could be adjusted. In conclusion, the research results has given us new understanding of the problems in the Qualification Assessment System which accounts for the majority of the current military construction contracts and provide validity on the government's expanded implementation of the Lowest Price Award System.

A Comparative Study on Korean Compulsory Multiple Prime Contract System (건설산업 제도개선을 위한 분할·분리 발주 제도의 선진화 방안 연구)

  • Kim, Sang-Bum;Cho, Ji-Hoon
    • Korean Journal of Construction Engineering and Management
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    • v.14 no.2
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    • pp.184-193
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    • 2013
  • Procurement System for Korean construction industry has mainly been controlled by the complicated regulatory system which has been recognized as unflexible and remotely separated from the global standard. This has been identified by many Korean construction experts as one of the main reasons that hamper the Korean construction industry becoming the global leader. One commonly discussed regulatory system is the compulsory multiple contracting system that has been enforced for a long time. According to the Korean governmental contracting law 68-3, all construction projects cannot be divided into separate contracting packages with a few exceptions. Exceptions stated in the law include construction activities related electrical, Information communication, fire-fighting, and cultural assets which all are governed by the separate laws/acts controlled by the different governmental bodies. This research is to closely investigate multiple prime contracting system that has been compulsory in Korean construction industry and to provide policy recommendations to these restrictions. Although, there has been a long history of this compulsory contracting system, this study attempted to provide objective analysis on current status of the system as well as global standard on the issue. This study suggests main considerations when considering different contracting system such as rights of owners, flexibilities of regulatory systems, and efficiencies of conducting a construction project. It is envisioned that recommendations from this study, if accepted by the regulatory bodies, would improve the Korean construction contraction system by making it more compatible with global standard. Moreover, these would help making the Korean industry more effective in terms of regulatory restrictions.

Revision of related Regulations and Construction Standards for the Use of Information on Underground Facilities Quality Level (지하시설물 품질등급 정보의 활용을 위한 관련 규정 및 건설기준 개정 방안)

  • Park, Joon Kyu;Kim, Tae Hoon;Kim, Won Dae
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.40 no.4
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    • pp.343-350
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    • 2022
  • The computerization project for underground facilities in Korea began in earnest after the city gas explosion in Seoul in 1994, and the Daegu subway explosion in 1995. As such a large-scale gas explosion accident caused enormous economic loss including human casualties and potential benefits, the need for computerized for efficient management of underground facilities was greatly emphasized in society. Meantime, computerization of underground facilities has been carried out according to the basic plan for building national geographic information system. In this study, problems were identified based on the current status of construction and management of underground facility information, as well as laws and regulations, and directions for establishing quality standards were presented. In addition, construction work standards such as 「Public Survey Work Regulations」, design standards, standard specifications, and technical specifications, gas technology standards, design standards, and communication works so that underground facility information can be linked and utilized in construction work by examining the linkage of the underground facilities, the targets that can be used for quality level information on underground facilities were derived, and a proposal to revise the construction standards was presented. In the future, if the quality standards are established, it is expected that the accuracy and utilization in the construction field will be increased.

A Study on the Calculation of Optimal Compensation Capacity of Reactive Power for Grid Connection of Offshore Wind Farms (해상풍력단지 전력계통 연계를 위한 무효전력 최적 보상용량 계산에 관한 연구)

  • Seong-Min Han;Joo-Hyuk Park;Chang-Hyun Hwang;Chae-Joo Moon
    • The Journal of the Korea institute of electronic communication sciences
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    • v.19 no.1
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    • pp.65-76
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    • 2024
  • With the recent activation of the offshore wind power industry, there has been a development of power plants with a scale exceeding 400MW, comparable to traditional thermal power plants. Renewable energy, characterized by intermittency depending on the energy source, is a prominent feature of modern renewable power generation facilities, which are structured based on controllable inverter technology. As the integration of renewable energy sources into the grid expands, the grid codes for power system connection are progressively becoming more defined, leading to active discussions and evaluations in this area. In this paper, we propose a method for selecting optimal reactive power compensation capacity when multiple offshore wind farms are integrated and connected through a shared interconnection facility to comply with grid codes. Based on the requirements of the grid code, we analyze the reactive power compensation and excessive stability of the 400MW wind power generation site under development in the southwest sea of Jeonbuk. This analysis involves constructing a generation site database using PSS/E (Power System Simulation for Engineering), incorporating turbine layouts and cable data. The study calculates reactive power due to charging current in internal and external network cables and determines the reactive power compensation capacity at the interconnection point. Additionally, static and dynamic stability assessments are conducted by integrating with the power system database.

Development of Embedded based Sea Operation Monitoring System (임베디드 환경의 해상작업 모니터링 시스템 개발)

  • Jung, Sung-Hun;Rhee, Bong-Keun;Yim, Jae-Hong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.2
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    • pp.93-97
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    • 2005
  • Sea operation monitoring system is a system for the automatic ship operation that is used on the variety sea operations such as laying optical cables on the sea between the countries, laying cables on the seabed for a remote island, laying pipelines for the natural gas, and so forth. This system processes data which optained through setting up environment and input from several sensors, and display GPS information with ENC data. And this system processes not only data of root file about sea operation, but also realtime information from PDA of client wirelessly connected with AP on wireless LAN, In addition, this system can improve efficiency of the operation as a result of enabling free movement within valid range. This paper design and Implementation Monitoring system from above appropriate to the embedded system, and improve competitive power of ship through prevention of a ship accident, to keep minimizing operation loads and support both the automatic ship operation and the safety voyage.

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Real-time Water Supply Facilities Monitoring System based on the USN (USN 기반의 실시간 수도설비 모니터링 시스템)

  • Kim, Yong-Tae;Yoo, Neung-Hwan;Park, Gil-Cheol;Kim, Seok-Soo;Kim, Tai-Hoon;Lee, Sang-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.6
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    • pp.1207-1213
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    • 2007
  • This paper has researched water supply facilities management using real-time water utility monitoring system based on USN(Ubiquitous Sensor Network) which is consisted of wireless sensors transferring waterworks facilities md treatment information about a valve-room and flowmeter-room of water supply installation. In the manholes, it was installed with flowmeter, pressure sensors, vibration sensors, Co-sensors, and hydro-thermograph sensors. These measurement values which are received by PDA are used for facilities operation on the spot safely and conveniently. It has also provided safe installation management via CDMA(Code Division Multiple Access) network which transfers data to remote servers to monitoring at a distance place. With safety management system of water supply facilities on USN technology convenience and safety is increased in real situation, and it is expected that we can supply clean water to people as much safer and more effective water supply installation management.

Modeling and Simulation of Small and Medium-sized Ships for Fuel Reduction Rate Verification (연료 감소율 검증을 위한 중소형 선박의 모델링 및 시뮬레이션)

  • Kim, Sung-Dong;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.26 no.6
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    • pp.914-921
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    • 2022
  • The International Maritime Organization (IMO) has set a goal of reducing ship's carbon dioxide emissions by 70% and greenhouse gas emissions by 50% by 2050 compared to 2008. Shipowners and shipyards are promoting various R&D activities such as LNG propulsion, ammonia propulsion, electric propulsion, CO2 capture, and shaft generators as a way to satisfy this problem. The dual shaft generator has the advantage that it can be directly applied to an existing ship through remodeling. In this paper, the total fuel reduction rate that can be obtained by applying the shaft generator to the existing ship was verified through simulation. For this purpose, the size of the medium-sized ship was defined, and the governor, diesel engine, propeller, torque switch, generator for shaft generator, propulsion motor for shaft generator, and ship model were modeled and simulated.

Helmet and Mask Classification for Personnel Safety Using a Deep Learning (딥러닝 기반 직원 안전용 헬멧과 마스크 분류)

  • Shokhrukh, Bibalaev;Kim, Kang-Chul
    • The Journal of the Korea institute of electronic communication sciences
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    • v.17 no.3
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    • pp.473-482
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    • 2022
  • Wearing a mask is also necessary to limit the risk of infection in today's era of COVID-19 and wearing a helmet is inevitable for the safety of personnel who works in a dangerous working environment such as construction sites. This paper proposes an effective deep learning model, HelmetMask-Net, to classify both Helmet and Mask. The proposed HelmetMask-Net is based on CNN which consists of data processing, convolution layers, max pooling layers and fully connected layers with four output classifications, and 4 classes for Helmet, Mask, Helmet & Mask, and no Helmet & no Mask are classified. The proposed HelmatMask-Net has been chosen with 2 convolutional layers and AdaGrad optimizer by various simulations for accuracy, optimizer and the number of hyperparameters. Simulation results show the accuracy of 99% and the best performance compared to other models. The results of this paper would enhance the safety of personnel in this era of COVID-19.

A Study of Automatic Fire Detection Installation based CAN Comunnication (CAN 통신기반 자동화재탐지설비에 관한 연구)

  • Kim, Young-Dong;Oh, Guem-Kon;Kang, Won-Chan
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.2
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    • pp.50-59
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    • 2006
  • In this paper, We are going to propose the fire protection system using CAN(Controller Area Network). The larger, higher and deeper buildings an, the more dangerous people are when fire happens. We should be aware of the problems of prior fire protection system. Therefore, we construct the embedded system based on CAN communication that is capable of N to N communication, and build independent fire protection system. If the fire is occurred on the building, the problem is that how fast we can detect the fire and put it on by using available system, this is major factor that reduces damage of our wealth. Therefore in this studies, We would like to design more stable system than current system. This system is based on CAN communication which is available N to N communication constructs and designed to compensate for each fault, so that our aim is to reduce the wires of system, cost of installation and to suppose future type fire protection system.

A Study on the Application of Cross-Certification Technology for the Automatic Authentication of Charging Users in ISO 15118 Standard (ISO 15118 충전 사용자 자동인증을 위한 교차인증서 기술의 적용에 관한 연구)

  • Lee, Sujeong;Shin, Minho;Jang, Hyuk-soo
    • The Journal of Society for e-Business Studies
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    • v.25 no.2
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    • pp.1-14
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    • 2020
  • ISO 15118 is an international standard that defines communication between electric vehicles and electric vehicle chargers. Plug & Charge (PnC) was also defined as a technology to automatically authenticate users when using charging services. PnC indicates automatic authentication technology where all processes such as electric vehicle user authentication, charging and billing are automatically processed. According to the standard, certificates for chargers and CPSs (Certificate Provisioning Services) should be under the V2G (Vehicle to Grid) Root certificate. In Korea, the utility company operates its own PKI (Public Key Infrastructure), making it difficult to provide chargers under the V2G Root Certificate. Therefore, a method that can be authenticated is necessary even when you have different Root Certificates. This paper proposes to apply cross-certificate technology to PnC authentication. Automatic authentication of Cross Certification is to issue a cross-certificate of the Root CA and include it in the certificate chain to proceed with automatic authentication, even if you have different Root certificates. Applying cross-certificate technology enables verification of certificates under other Root certificates. In this paper, the PnC automatic authentication and cross certificate automatic authentication is implemented, so as to proceed with proof of concept proving that both methods are available. Define development requirements, certificate profiles, and user authentication sequences, and implement and execute them accordingly. This experiment confirms that two automatic authentication are practicable, especially the scalability of automatic authentication using cross-certificate PnC.