• Magazine of the Korean Society of Agricultural Engineers
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• v.12 no.2
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• pp.1965-1970
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• 1970

The experiment was carried out in order to improve the leakage stopping work in the irrigation canal founding on the porous soil. But the experiment had many problems to be studied more owing to the insufficient time and facilities. The results obtained are summarized as follows; 1. Polyethylene film is estimated not to make strength decrease owing to buring in the subsoil, but to make owing to the sunlight. 2. Coated nylon shows the tendency to deteriorate strength when it is buried in the earth or exposed to the sun for long time, but leakage is all but impermeability generally. 3. Leakage loss rates for one hour show some differences in the canal to be full with water in accordance with operating methods, that is, the clay lining section is 12.6%, the coated nylon lining section is 1.7%, the polyethylene film lining section is 1.3%, respectively. 4. Leakage quantities per wetted perimeter unit area show $3.556cc/cm^2/hr$. in the clay lining section, $1.574cc/cm^2/hr$. in the coated nylon section, $0.695cc/cm^2/hr$. in the polyethylene film lining section, respectively. 5. When the construction fund make the clay lining section as a standard, the polyethylene film section is 92.1%, the coated nylon section is 174.2%, respectively. But, the unit cost of execution may be low when the polyethylene film and the coated nylon will enable to mass-produce for the purpose of execution.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.8
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• pp.784-789
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• 2011

In this paper, a tunable integrated transmitter leakage canceller based on an autotransformer for ultra-high-frequency (UHF) RFID readers is presented. The proposed TX leakage canceller consists of an autotransformer, a digital tuning capacitor, a voltage controlled tuning resistor, and a compensating amplifier, and it is designed using 0.13 ${\mu}m$ 1-poly 6-metal RF CMOS process. The simulation results show that the proposed structure has over 55 dB rejection characteristic between a transmitter and a receiver and a 2.5 dB of the RX insertion loss. The TX leakage canceller can be digitally tuned from 825 MHz to 985 MHz with the tuning capacitor and it can be fully integrated.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.12
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• pp.2333-2340
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• 2017

Recently industry is suffering severe losses of important internal information, and most of the leaks result from the insiders. Thus, various technological counter measures are being studied in order to protect private organization information. In this paper, among various internal information leakage path protection mechanisms, we propose a technique for preventing files which are defined as confidential from being copied or moved through USB. The implemented confidential file loss prevention system is composed of both signature insert manager and confidential file detect manager. The signature insert manager allows a system administrator to insert a special pattern specifying a classified confidential file, while the confidential file detect manager protects confidential file leakage when a user attempts to move or copy a confidential file to the USB memory. This results would be contributed to reducing the damage caused by leakage of confidential files outside of the company via USB.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.8
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• pp.1597-1603
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• 2017

The incidence of fire in underground utility tunnel is lower than other fires, but the damage caused by fire can cause social loss due to social management paralysis as well as economic loss. Hereupon, this paper presents the results of an empirical test on the construction of the underground utility tunnel condition monitoring system using the leakage coaxial cable installed in the underground utility tunnel. For this reason, a verification test was conducted by connecting a inductive coupler 200 Mbps power line communication modem with insertion loss characteristics of $-6{\pm}2dB$ to the installed the leakage coaxial cable installed in the underground utility tunnel. As a result, We confirmed sending/receiving of IP cameras up to 500 m. Therefore, it is judged that it is possible to construct a condition monitoring system for underground utility tunnel by using the leakage coaxial cables installed in the underground utility tunnels without installing additional communication lines for data transmission.

• Journal of Korean Society of Water and Wastewater
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• v.35 no.3
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• pp.237-246
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• 2021

The ILI, developed by the IWA (International Water Association), has been used in many countries as an indicator of water leakage. In Korea, the revenue water has been used as a performance indicator for waterworks although there is an opinion to replace it with the ILI. Hence, it has been necessary to investigate whether the ILI can replace the revenue water in Korea. The four main operating indicators (i.e., water service population, profit-loss ratio, fiscal self-reliance, and aged pipe rate) of 162 Korean waterworks were compared with the ILI with the linear regression method. Local water authorities with more than 1 million water service population, with more than 60% profit-loss ratio, more than 40% and less than 60% fiscal self-reliance, and more than 20% aged pipe rate showed meaningful correlation between the four parameters and the ILI. In the remaining cases, their correlations were little or weak. This means that using the ILI may not be an efficient method to represent the performance of the water supply system in Korea because of the lack of UARL (Unavoidable Annual Real Losses) data accuracy. To use the ILI in Korea, it will be required to carry out an additional research to accumulate reliable CARL (Current Annual Real Losses) and UARL data in the future.

• Journal of Korea Water Resources Association
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• v.55 no.spc1
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• pp.1223-1234
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• 2022

Efforts for reducing greenhouse gas emission coping with climate change have also been performed in the field of water and wastewater works. In particular, the technical development for reducing energy has been applied in operating water distribution system. The reduction of energy in water distribution system can be achieved by reducing structural loss induced by topographic variation and operational loss induced by leakage and friction. However, both analytical and numerical approaches for analyzing energy budget of water distribution system has been challengeable because energy components are affected by the complex interaction of affecting factors. This research drew mathematical equations for 5 types of state (hypothetical, ideal, leak-included ideal, leak-excluded real, and real), which depend on the assumptions of topographic variation, leakage, and friction. Furthermore, the derived equations are schematically illustrated and applied into simple water network. The suggested method makes water utilities quantify, classify, and evaluate the energy of water distribution system.

• Convergence Security Journal
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• v.14 no.4
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• pp.109-116
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• 2014

Personal information leakage in financial corporations including three card corporations has occurred constantly this year. It is due to incomplete encryption system and negligent personal security. Solicitors are known as a cause of information leakage because they operate with leaked information. Information leakage can cause secondary damage with mental demage to person and result in a drop in reliability as well as an operating loss in financial corporations. Also because it can destroy a base of credit society, prevention of recurrence is badly needed. The government finally announced 'general measures for prevention of information leakage in the field of finance' with sanctions reinforcement and restriction to collect, possess, provide personal information as the main agenda. And a related law revision is going in the National Assembly. In this paper, effectiveness of government measures is weighed with the cause analysis of information leakage and countermeasure for prevention of information leakage is found.

• Fire Science and Engineering
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• v.31 no.1
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• pp.1-9
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• 2017

This study conducted Testing, Adjusting, and Balancing (TAB), which is a type of field performance evaluation experiment of a zone smoke-control system, at a railway underground transit passage installed with a zone smoke- control system to find problems and improvements for ensuring performance. TAB for the smoke control system was classified into several procedures, such as design data review, duct leakage test, field measurement of the airflow rate, velocity of the fan and duct, and a smoke test. Through the duct leakage test, the system leakage ratio was examined to prove the duct sealing. The iImprovement of the smoke control airflow problems due to the lack of fan static pressure loss was the secured performance. The performance of the smoke control fan was secured by improvements of the smoke control airflow rate problems caused by the loss of static pressure in the intake duct. The smoke test in the smoke control zone confirmed that the damper operating schedule subject was influenced by natural wind or train wind.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.5
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• pp.961-968
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• 2014

In order to prevent leakage of personal information by insiders a large number of companies install pc security solutions like DRM(Digital Right Management), DLP(Data Loss Prevention), Personal information filtering software steadily. However, despite these investments anomalies personal information occurred. To establish proper security policy before implementing pc security solutions, companies can prevent personal information leakage. Furthermore by analyzing the log from the solutions, companies verify the policies implemented effectively and modify security policies. In this paper, we define the required security solutions installed on PC to prevent disclosure of personal information in a variety of PC security solution, plan to integrate operations of the solutions in the blocking personal information leakage point of view and propose security policies through PC security solution log analysis.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.5
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• pp.1-12
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• 2018

The streamline curvature method is essentially used for the design procedure of multi-stage axial turbines. Moreover, by using this method, it is possible to consider the turbine loss characteristics for real operating conditions at an early design stage. However, there is not enough relevant research in South Korea to support this. In the present study, the streamline curvature method and the empirical equation for calculating the mixing loss are employed to predict the performance of a multi-stage axial turbine with leakage flows. The proposed method is applied to the prediction of the performance of a five-stage axial turbine with leakage flows, as used for an industrial gas turbine of 86 MW in South Korea. The calculation result is compared with 3D CFD data, and the advantages and limitations of the streamline curvature method are described.