• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.27 no.11
• /
• pp.82-88
• /
• 2013

It is important to give lightning warning prior to a cloud-to-ground (CG) discharge within an Area of Concern (AOC) because most of lightning damage and victim are usually occurred by the first lightning in the AOC. The aim of this study is to find the optimal operation conditions of the automated lightning warning systems in order to make the best use of the available data. In this paper, the test-operated results of the automated lightning alert and risk management system (ALARM) based on detections of CG discharge and eletrostatic field and optimized at probability of lightning have been described. It was possible to obtain the following warning performance parameters: probability of detection (POD), false alarm ratio (FAR), probability of lightning (POL) and failure-to-warn rate (FTW). The data obtained from trial operation for 5months were not sufficient but the first analysis of domestic lightning warning was carried out. We have observed that the evaluated statistical results through trial operation depend on the various factors such as analysis methods and criteria, topographical conditions, etc. Also we suggest some methods for improvement of POL and POD including the finding of the optimal electric field threshold level to be used, based on the high values of FAR and FTW found in this work.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.51 no.9
• /
• pp.433-440
• /
• 2002

The addition of switches to a distribution feeder does, in general, increase reliability by decreasing the duration of the outage of many to the customers on the feeder. To cover its service area so that feeder-level delivery reaches sufficiently close to all customers, feeders typically split their routes many times, in what is often called a lateral feeder. It is interesting to note, however, that the effectiveness of a switch is very much dependent on the types of lateral feeder. The types of lateral are classified into two types. The first is loop lateral feeder that can connect its load to an adjacent feeder through a tie line in case that a fault occurs in its feeder and it is laid out so that every feeder has complete fault backup through re-switching of its loads to other sources like a main feeder The second is the radial lateral feeder cannot connect its load to an adjacent line, no provision is made for contingency backup of feeders. There are no other circuits in the radial lateral feeder form which to restore power. In this study, we evaluate the effectiveness of a switch installation between on the radial and loop lateral feeders to increase reliability by decreasing the duration of the outage. These results can help power utility to design the switch layouts on the radial and loop lateral feeder system.

• The Journal of Sustainable Design and Educational Environment Research
• /
• v.15 no.2
• /
• pp.23-33
• /
• 2016

This research as an obstacle -free living environment certification mandatory school facilities based on studies of BF accreditation indicators of school facilities, BF Survey and Analysis amenities installation status of school facilities based on the certified assessment indicators and school facilities improvement of the accreditation indicators for BF was to explore. Excellent facilities via one of the surveyed schools selected as school facilities, the comparison analyzing the current status and BF certification evaluation indicators within the facility, the intermediate facility entry access, handicapped parking areas, main entrance item BF was to meet the minimum standards of accreditation indicators. For internal facilities BF accreditation indicators have applied the same criteria to all buildings less than that is not reflected in layout and space planning, environmental planning of school facilities was analyzed that showed the limits conflict with installation.

• Journal of the Korean Society of Safety
• /
• v.33 no.1
• /
• pp.62-65
• /
• 2018

The rapid progress toward the 4th industrial society has led to possibilities of fire increase. It is pointed out that, though initial fire suppression is emphasized, the current legal systems do not sufficiently recognize the importance of initial fire suppression. In order to resolve this, problems of the current legal systems and regulations, as well as fire-fighting facilities to be equipped according to the size of specific fire-fighting objects, were diagnosed. Also, suggestions for improvement were provided through comparative analysis with relevant laws and technical regulations of Korea and other countries. According to fire safety standards such as NFPA, IMO, ISO, and Russian standards, automatic fire extinguishers are to be installed as per the adaptability criteria of fire extinguishers and automatic fire extinguishers. In Korea, the "Act on Fire Prevention and Installation, Maintenance, and Safety Control of Fire-fighting Systems" cover the types and scope of fire fighting facilities that include specific fire protection objects, such as electric room, power room, and substation room. This study has identified that, in case of a place with a floor area of less than $300m^2$, the installation requirement is not clearly specified. Therefore, in this study, fire extinguishing equipment and automatic fire extinguishing equipment to be added for each sub-use application are proved to have fire extinguishing performance of Class A, Class B, and Class C, respectively. In view of the fact that, in overseas standards, all space except containing such materials as Deep fire, metal fire and peroxide, can be installed with fire fighting equipment, a legal system for specifying the capacity units of fire fighting apparatus by application is, in this study, proposed.

• Clean Technology
• /
• v.17 no.4
• /
• pp.353-362
• /
• 2011

In our nature, the utilization of rainwater is essential for healthy water recirculation. This is one of the solutions of the increment of impermeability surface according to the development of new cities; this study of the improvement of rainwater quality has been carried on through the improvement of collecting and restoring system of rainwater. The southwestern region of Daejeon City, the rainwater coefficient of run off was 0.40 and this number had computed to 0.59 after the development. After filtration of rainwater, the heavy metal (Cu, As, Cr, Fe, Mn) contents level were lower than underground water. Moreover, collected rainwater showed better quality than underground water in following criteria; hardness, permanganate consumption quality, chloride, evaporation residue, sulfates and nitrate nitrogen. This water quality met the gray water quality standards. The rainwater quality was still suitable to use as bathroom flushing and gardening after 100 days of storage. This study proved that modification (installation of cover with gutter to existing rainwater collection system, proper filtering, and installation of underground storage tank) of collection system could improve quality of water and maintain this approximately 100 days.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.21 no.6
• /
• pp.77-84
• /
• 2007

It is increased electrical energy consumption with the development of intelligence society in hospitals and thus an energy conservation through efficient use of electricity became more important. This paper shows a reasonable design demand factor in hospitals, that was made by the systematic and statistical way considering actual conditions, such as investigated electric equipment capacity, peak power consumption, demand factor, etc., for 32 hospitals and 9 electrical design offices. In this dissertation, it is necessary to analyze the key features and general trend from the investigated data. It made an analysis of the feature parameters, such as average, standard deviation, median, maximum, minimun and thus it was carried the linear and nonlinear regression analysis.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.20 no.2
• /
• pp.186-192
• /
• 2014

In this paper, we analysed vessel traffic volume and patterns of traffic flow for ships using areas where included wind farm site and adjacent waters of Daejeong Offshore Wind Farm, and estimated traffic volume by classified navigational routes according to suggestion of rational routeing measures on the basis of classified patterns after installation of offshore wind facilities. Also, we assessed vessel traffic safety for each designed routeing measures on the basis of estimated traffic volume and proposed requisite countermeasures for the safe navigation of ships. With a result of analysing patterns of traffic flow, the current traffic flow was classified by 8 patterns and the annual traffic volume was predicted to 8,975 ships. On the basis of these, expected the vessel traffic volume according to designed four routeing mesaures after installation of wind farm. As result of assessing vessel traffic safety by using powered-vessel collision model of SSPA on the basis of the estimated traffic volume, the value of collision probability was less than safe criteria $10^{-4}$. Thereby we made sure usability of the designed routeing measures for the safe navigation of ships.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.15 no.3
• /
• pp.45-50
• /
• 2001

Fuzzy theory is used to quantify some subjective criteria and consider uncertain factors for transmission line reinforcement planning in this paper. Sugeno's fuzzy integral is also used in the proposed method, because it can be easily allied to multi attribute decision making problems such as power system planning. To verify the proposed algorithm, some bode-neck lines are searched for the case that the amount of Maximal Load Supplying Capability(MLSC) is small using the results of contingency analysis for Korea Electric Power Corporation(KEPCO)'s 345[kV] transmission line in 1998. And several feasible alternatives are composed for line reinforcement which can dissolve the bottle-neck.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2006.05a
• /
• pp.120-124
• /
• 2006

In this study, psychological assessment was carried out to investigate the driver's psychological characteristics by the change of the headlight. The participants were 20 men and 20 women in their 20s and thirty-two different conditions in combinations of waveform of light, voltage, and alteration time were used. The questionnaire for the assessment was evaluated by 8 subjective items and 5-point SD criteria of 19 pair's adjective. The results were as follows. 1. The assessment results from SD method indicated 3 factors by factor analysis, and it was shown that A waveform had significances in a sense of security and impetus and B waveform had a significance in a sense of security The levels of the limitations for the voltage change were 12V in the factor of a sense of security and 11V in the factor of a sense of impetus for A waveform, 12.6V in the factor of a sense of security for B waveform. 2. The results of the subjective assessment showed that the limitation of A waveform's brightness change was 12V. Moreover, the limitations of voltage changes were 12.6V for B waveform brightness change, 12V for discomfort, 12.6V for darkness. And the limitation of C waveform's brightness change was 12V.

• Journal of Korean Society of Transportation
• /
• v.21 no.4
• /
• pp.103-111
• /
• 2003

This study proposes methodology deterimining a basic pedestrian crossing capacity that plays a critical role in the installation of pedestrian signal at the crosswalks. The methodology is based on the pattern of vehicle arrived at the crosswalks. Erlang distribuion is used as headway distribution that can cover the various levels of flow rate. Models using Erlang distribution are represented by Erlang parameter (K) of 1, 2, or 3 at 2-, 4-, or 6-lane roadway in both directions. In addition, this study considered the only type of road with a pedestrian refuge area in the median that is used to wait for the allowable gap provided by the flow of another direction. As a result, the pedestrian capacity decreases as flow rate increases and Erlang parameter increases for the road with the pedestrian refuge. This study develops the models to determine the pedestrian capacity under a variety of flow rates and the outcomes of this study could be used as the criteria for the determination of the installation of pedestrian signal or for the provision of pedestrian refuge in the median of road.