• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.3
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• pp.127-133
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• 2005

Programmable Logic Controller(PLC) is the most widely utilized and plays an important role in industrial control system. The study about a PLC language is performed actively. Ladder Diagram(ID) is the most widely used in PLC. In is not suitable for describing a complex sequential logic and is very difficult to grasp the sequential flow of control logic and has the disadvantage for a maintenance. On the other hand, Sequential Function Chart(SFC) is very easy to grasp the sequential flow of control logic and has the compatability for a maintenance but has the disadvantage for describing a condition and a interlock logic. In this paper, we propose the method that describe the interlock logic using management step, and confirm his feasibility through a actual examples.

• Journal of the Korea Safety Management & Science
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• v.16 no.4
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• pp.379-389
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• 2014

Fire detectors are designed to minimize loss of life from a fire alarm system as an alarm to help evacuate more quickly until the completion of the evacuation alarm should be continued. the purpose of such alarms in order to achieve the characteristic fire heat release rate reaches a certain level, or when a certain time has elapsed, when the heat detector is to be alarms to answer. Requires a quick response, it is desirable to install the sensor as much as possible, but taking into account the cost of installation problems by engineering approach to minimize the quantity and rapidity of detection capability should be increased. In order to increase the rapidity of fire detectors in a room according to the height of the sensing period is to be maintained the optimum distance of the fire detector detects characteristics should be considered. Differential spot-type heat detectors installed domestic basis, depending on the type of sensor that can detect one sensor area is limited and less than 4m ceiling height regulations and simply double the number in excess of 4m and intended to be installed.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1389-1396
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• 2008

The recent Sichuan earthquake(2008) in China and Iwate-Miyazaki earthquake(2008) in Japan give Korea peninsula warning that it is no more safety zone against damage by earthquake events. So, rapid and appropriate countermeasures for dam operation and management against earthquake are needed. In Korea earthquake design standard(MOCT, 1997) has been revised after Kobe earthquake. Installation of seismometer and monitoring of earthquake for special class dams is requlated in dam aseismic design standard(MOCT, 2001). Accelerometer installation project for existing dams has been carrying out by K-water to establish an earthquake network for dam safety. Real-time dam earthquake monitoring network has also been developed to detect an earthquake efficiently and to warn to dam administrators as soon as possible. In this study, dam real-time earthquake monitoring system developed by K-water was introduced and applicability of real earthquake record measured by this system to dam safety management was illustrated.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.11
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• pp.39-49
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• 2011

Smart Grid has two main objectives on both supply and demand aspects which are to distribute the renewable energy sources on supply side and to develop realtime price responses on demand side. Renewable energy does not consume fossil fuels, therefore it improves the eco-friendliness and saves the cost of power system operation at the same time. Demand response increases the flexibility of the power system by mitigating the fluctuation from renewable energies, and reduces the capacity investment cost by shedding the peak load to off-peak periods. Currently Smart Grid technologies mainly focus on energy monitoring and display services but it has been proved that enabling technologies can induce the higher demand responses through many pilot projects in USA. On this context, this paper provides a price responsive algorithm for HEMS (home energy management system) on the real time pricing environment. This paper identifies the demand response as a core function of HEMS and classifies the demand into 3 categories of fixed, transferable, and realtime responsive loads which are coordinated and operated for the utility maximization or cost minimization with the optimal usage combination of three kinds of demand.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.8
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• pp.70-81
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• 2011

In this paper, a multi-agent control system for DC-coupled photovoltaic (PV), fuel cell (FC), ultracapacitor(UC) and battery hybrid power system is studied for commercial buildings & apartment buildings microgrid. In this proposed system, the PV system provides electric energy to the electrolyzer to produce hydrogen for future use and transfer to the load side, if possible. Whenever the PV system cannot completely meet load demands, the FC system provides power to meet the remaining load. A multi-agent system based-power management and control algorithm is proposed for the hybrid power system by taking into account the characteristics of each power source. The main works of this paper are hybridization of alternate energy sources with FC systems using long and short storage strategies to build the multi-agent control system with pragmatic design, and a dynamic model proposed for a PV/FC/UC/battery bank hybrid power generation system. A dynamic simulation model for the hybrid power system has been developed using Matlab/Simulink, SimPowerSystems and Stateflow. Simulation results are also presented to demonstrate the effectiveness of the proposed multi-agent control and management system for building microgrid.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.6
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• pp.127-133
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• 2008

This paper presents the battery management system(BMS) for the optimum conditions of the lead-Acid battery in UPS. The proposed system control the currents and voltages of battery for optimum conditions to estimate the State Of Charge(SOC) in charge or discharge mode. It proved the performance and the algorithm for the estimation of SOC, through the experiments which using the charge and discharge tester and the field tests.

• Journal of Korean Society of Water and Wastewater
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• v.33 no.4
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• pp.259-268
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• 2019

One of the most effective methods to consistently ensure the safety of a tap water supply can be achieved by application of a comprehensive risk assessment and risk management approach for drinking water supply systems. This approach can be termed water safety plans(WSP) which recommended by WHO(world health organization) and IWA(international water association). For the introduction of WSP into Korea, 150 hazards were identified all steps in drinking water supply from catchment to consumer and risk assessment tool based on frequency and consequence of hazards were developed. Then, developed risk assessment tool by this research was implemented at a water treatment plant($Q=25,000m^3/d$) to verify its applicability, and several amendments were recommended; classification of water source should be changed from groundwater to stream to strengthen water quality monitoring contaminants and frequencies; installation of aquarium to monitor intrusion of toxic substances into raw water; relocation or new installation on-line water quality analyzers for efficient water quality monitoring; change of chlorination chemical from solid phase($Ca(OCl)_2$) to liquid phase(NaOCl) to improve soundness of chlorination. It was also meaningful to propose hazards and risk assessment tool appropriate for Korea drinking water supply systems through this research which has been inconsistent among water treatment authorities.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.367-374
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• 2013

Underground infrastructure systems provide essential public services and goods through buried structures including water and sewer, gas and petroleum, power and communication pipelines. The majority of existing underground infrastructure systems was installed in green field areas prior to development of complex urban built environments. Currently, there is a global trend to escalate major demand for underground infrastructure system renewal and new installation while minimizing disruption and maintaining functions of existing superstructures. Therefore, Engineers and utility owners are rigorously seeking technologies that minimize environmental, social, and economic impact during the renewal and installation process. Trenchless technologies have proven to be socially less disruptive, more environmentally friendly, energy conservative and economically viable alternative methods. All of those benefits are adequate to enhance overall sustainability. This paper describes effective sustainable solutions using trenchless technologies. Sustainability is assessed by a comparison between conventional open cut and trenchless technology methods. Sustainability analysis is based on a broad perspective combining the three main aspects of sustainability: economic; environmental; and social. Economic includes construction cost, benefit, and social cost analysis. Environmental includes emission estimation and environmental quality impact study. Social includes various social impacts on an urban area. This paper summarizes sustainable trenchless technology solutions and presents a sustainable construction method selection process in a proposed framework to be used in urban underground infrastructure capital improvement projects.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.8A
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• pp.1144-1152
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• 2000

In order to guarantee the user-requested quality-of-service(QoS) and keep the network utilization at maximum it is required to manage the network performance continuously after the network installation. The performance management function should provide the useful information for the network expansion and the capacity reallocation in the future. Currently the TINA provides the specification of the management function of configuration management connection management and fault management ; but the management function of performance management and security management are not well-defined yet. In this paper we propose a TINA-based performance management architecture for the efficient performance management of the heterogeneous networks or NEs with TMN and SNMP management functions. And we examine the proposed architecture into the ATM network (with SNMP and TMN) monitoring. The proposed architecture is based on the distributed processing architecture and the concept the TMN perfo mance management. The proposed architecture have been designed and implemented in multiprocess and multithread structure.

• Journal of the Korea Safety Management & Science
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• v.18 no.4
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• pp.57-72
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• 2016

There are more than 30,000 chemical substances handled in domestic university laboratories. Among them, hazardous materials are selected and managed as designated substances by the standards of 19 Ministries and 16 Acts. However, domestic safety-related laws and regulations are used to manage industrial risk factors based on industrial activities. In case of installing a university chemical laboratory in accordance with the installation standards applicable to general workplaces. It is not suitable to use as a laboratory installation standard that can be applied to a chemical laboratory installed at a university such as a problem occurs in applying to a university using a small quantity of dangerous substances in a small amount. In order to establish the laboratory structure and facility standards that are appropriate for the laboratory characteristics and apply systematic laboratory safety, the National Security Administration shall apply the special handling standard of chemical experiment to places where handling less than 30 times the designated quantity of chemical substances for chemical experiments. On August 2, 2016, the regulations for the enforcement of the Dangerous Goods Safety Management Act and the standards for the structure and facilities of the university chemical laboratory were enacted. In this study, we investigated the domestic chemical substances laws and regulations to determine the chemical substances that are over-regulated in the relevant laws, and define them as substances against accidents. The management criteria for the substances were analyzed. The R value for the designation of the designated quantity by the concept of the space in the management standard was calculated.