• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.8
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• pp.1392-1397
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• 2008

The mechanical integrity of generator stator windings is one of the critical point because the electric power is generated and conducted to power system through these windings. De-mineralized water is used to cool stator bars during the normal operation of generator in large power plants because the water cooled method has highest cooling efficient. Water absorption of bar insulation is progressed by several causes such as generation of water leak path by corrosion, delamination of insulation by vibration, and inadequate water treatment, etc.. Reliable water absorption diagnostics of generator stator bar is important to ensure the availability of power plant and to reduce maintenance cost by generator accident. It is described that the water absorption characteristics for generator stator bar insulation used in 500MW capacity standard fossil power plant by cooling water temperature. It is verified that the management of stator cooling water temperature is one of the important factors to decrease water absorption rate of generator stator bars.

• Journal of the Korean Society of Safety
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• v.26 no.5
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• pp.99-104
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• 2011

An ILRT Interval for a nuclear power plant in Korea was extended from once in five years to once in ten years. Therefore, it is necessary to evaluate risk impact for ILRT interval extensions. In this paper, input data were generated for the reference plants, KSNP, using raw data such as meteorological data, population distribution data and source term data. And, using MACCS II code the risk impact assessment was performed based on the two methodologies of NUREG-1493 and NEI Interim Report. The risk impact derived from an ILRT interval extension was identified not to be significant. It is considered to apply this study and results to making an accident management plan and safety goal, and to the field of public acceptance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.653-659
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• 2014

Computer simulation has been performed to optimize cold forging process of automotive LPI fuel filter housing. A mold and the test product have been manufactured considering the strain and load distribution during the cold forging process. Also, fuel flow simulation has been performed to analyze flow characteristics of existing model and new model. Simulation result shows that two models have equivalent pressure drop. Compared with the mass of existing product, raw material reduction of 16 g and 30.5 g has been achieved from the upper and lower housing, respectively. Total mass reduction of the new housing was 46.5 g. Leak test and internal pressure test have been performed to verify the safety standard and test results were satisfactory.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.7
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• pp.91-97
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• 2022

Pipes transport and supply fuel in various categories; however, corrosion occurs because of the external environment, impurities are mixed in the fuel, and substances leak to the outside, which can lead to serious accidents. Therefore, in this study, inspection equipment using a laser scanner was manufactured to classify conditions according to the degree of corrosion of the outer wall of the pipe, and the corrosion height and maximum value of the pipe were obtained from the surface information. Using the k-means method, it was classified into four states, and the standard of the average height and maximum height of corrosion for each state was derived.

• Journal of the Korea Society of Computer and Information
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• v.25 no.10
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• pp.125-133
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• 2020

In this paper, we design 4-layer TCP/IP that utilizes minimal memory and processor resources in Internet of Things(IoT) systems. The TCP/IP designed in this paper has the following characteristics. First, memory resource is minimized by using minimal memory allocation. Second, processor resource is minimized by using minimal memory copy. Third, the execution time of the TCP/IP can be completed in a deterministic time. Fourth, there is no memory leak problem. The standard in minimal resources for memory and processor derived in this paper can be used to check whether the network subsystems of the already implemented IoT systems are efficiently implemented. As the result of measuring the amount of memory allocation and copy of the network subsystem of Zephyr, an open source IoT kernel recently released by the Linux Foundation, we found that it was bigger than the standard in minimal resources derived in this paper. The network subsystem of Zephyr was improved according to the design proposed in this paper, confirming that the amount of memory allocation and copy were decreased by about 39% and 67%, respectively, and the execution time was also reduced by about 28%.

• Safety and Health at Work
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• v.4 no.2
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• pp.100-104
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• 2013

Background: The aim of this study was to assess public and private medical diagnostic laboratories in Nigeria for the presence of biosafety equipment, devices, and measures. Methods: A total of 80 diagnostic laboratories in biosafety level 3 were assessed for the presence of biosafety equipment, devices, and compliance rate with biosafety practices. A detailed questionnaire and checklist was used to obtain the relevant information from enlisted laboratories. Results: The results showed the presence of an isolated unit for microbiological work, leak-proof working benches, self-closing doors, emergency exits, fire extinguisher(s), autoclaves, and hand washing sinks in 21.3%, 71.3%, 15.0%, 1.3%, 11.3%, 82.5%, and 67.5%, respectively, of all laboratories surveyed. It was observed that public diagnostic laboratories were significantly more likely to have an isolated unit for microbiological work (p = 0.001), hand washing sink (p = 0.003), and an autoclave ($p{\leq}0.001$) than private ones. Routine use of hand gloves, biosafety cabinet, and a first aid box was observed in 35.0%, 20.0%, and 2.5%, respectively, of all laboratories examined. Written standard operating procedures, biosafety manuals, and biohazard signs on door entrances were observed in 6.3%, 1.3%, and 3.8%, respectively, of all audited laboratories. No biosafety officer(s) or records of previous spills, or injuries and accidents, were observed in all diagnostic laboratories studied. Conclusion: In all laboratories (public and private) surveyed, marked deficiencies were observed in the area of administrative control responsible for implementing biosafety. Increased emphasis on provision of biosafety devices and compliance with standard codes of practices issued by relevant authorities is strongly advocated.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.4
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• pp.75-90
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• 2004

At Asiacrypt 2003, Shin et al., have proposed a new class for Authenticated Key Establishment (AKE) protocol named Leakage-Resilient AKE ${(LR-AKE)}^{[1]}$. The authenticity of LR-AKE is based on a user's password and his/her stored secrets in both client side and server side. In their LR-AKE protocol, no TRM(Tamper Resistant Modules) is required and leakage of the stored secrets from $.$my side does not reveal my critical information on the password. This property is useful when the following situation is considered :(1) Stored secrets may leak out ;(2) A user communicates with a lot of servers ;(3) A user remembers only one password. The other AKE protocols, such as SSL/TLS and SSH (based or PKI), Password-Authenticated Key Exchange (PAKE) and Threshold-PAKE (T-PAKE), do not satisfy that property under the above-mentioned situation since their stored secrets (or, verification data on password) in either the client or the servers contain enough information to succeed in retrieving the relatively short password with off-line exhaustive search. As of now, the LR-AKE protocol is the currently horn solution. In this paper, we prove its security of the LR-AKE protocol in the standard model. Our security analysis shows that the LR-AKE Protocol is provably secure under the assumptions that DDH (Decisional Diffie-Hellman) problem is hard and MACs are selectively unforgeable against partially chosen message attacks (which is a weaker notion than being existentially unforgeable against chosen message attacks).

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.3
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• pp.212-221
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• 2013

Objectives: Asbestos fibers are accumulated in negative pressure unit (NPU) or vacuum cleaner in asbestos removal. Failure of operation or poor use performance of the NPU or vacuum cleaner causes asbestos fibers to spread in the air. Asbestos contractors should have an NPU fitted with a HEPA , vacuum cleaner, decontamination area, respirators, wetting equipment, and differential pressure manometer to register with the Ministry of Employment and Labor. There should be performance criteria of equipment used in asbestos removal. But there are none such criteria used in asbestos removal. This study was performed to investigate international or national performance criteria of equipment used in asbestos removal. Methods: Regulations, approved code of practice, guidance and national standards of the UK, USA and Korea were reviewed. A survey was done to investigate the requirements for equipment used in asbestos removal in Korea. Results: Air flow of NPUs used in Korea usually covers from$500m^3/h$ to over $3000m^3/h$. Some requirements for NPUs used in Korea were missing compared to the requirements of British standards for NPUs. All NPUs have different missing requirements. The UK also has separate British standard for leak tests for NPUs. Highly hazardous class vacuum cleaners should be used in asbestos removal in the UK. It has national standards on the operation of vacuum cleaners used in asbestos removal. There is only a certification system for less than 2.5kw rated voltage vacuum cleaners for home use in Korea. Powered (-assisted) respirators with mask are recommended in asbestos removal. Type 5 coveralls should be used in asbestos removal in the UK. There are international standards for requirements and leak tests of type 5 coveralls. A manometer for measuring differential pressure is needed in asbestos removal. The manometer's measuring range should cover less than ${\pm}125$ Pa and the gradation of manometer should be less than 2.5 Pa. The definition of decontamination area should be corrected. Installation of airlock and minimum area should be considered in decontamination area. Conclusions: Equipment should be used in asbestos removal proper performance and no leaks. There should be a certification system for equipment used in asbestos removal. This study can help to a certification system for equipment used in asbestos removal in Korea.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.5
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• pp.119-130
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• 2009

Korea ranked 2nd in the UN Global e-Participation Index and ranked number one as the leader in e-Government for the third consecutive year. However, Korea ranked 51 in the level of information security published by WEF(World Economic Forum), relatively a low level comparing with its great number of users and excellent environments for the Internet service. A series of critical hacking accidents such as the information leak at Auction and GS Caltex emerged consecutively in 2008 year, resulting in the leak of personal & critical information. This led to a strong interest in the necessity and importance of information security and personal information so that demand for IT security is growing fast. In this paper, we survey to benchmark information security in the perspective of service level, system, investment and policy about major foreign countries. Then we research on an effective way to make the most of the benchmark result to Korea e-Government. In addition, the purpose of this paper is to improve national information security index by developing a policy for ISO 27001 ISMS, an international standard for Information Security Management System, and elevate safety and security of the e-Government serviced by central administrative organizations and local authorities.

• Journal of the Korean Institute of Gas
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• v.25 no.6
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• pp.35-44
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• 2021

The PR (Photo Resist) process in the semiconductor process is a process that uses a mixture of flammable substances. Due to the process equipment is installed in a clean room and when flammable substances leak, there is a high risk of suffocation, fire, and explosion. It is necessary to analyze the impact of accidents that may occur during operation and to evaluate whether the safety of workers can be guaranteed. In this study, the value of radiant heat and temperature change at the monitor point set up virtual inside the clean room was confirmed through CFD simulation of 10 leak and fire scenarios using the FLACS CFD - Fire Module. A fire that occurs inside a clean room transfers high radiant heat to the inter-story structure, but its scope is quite limited, and it is unlikely that it will collapse in a single fire accident. There was no scenario in which two stairs leading to the exit were exposed to high radiant heat at the same time due to a fire accident, therefore workers were able to escape in case of a fire. In addition, it was confirmed that the level of radiant heat and temperature rise rapidly decreased as they moved downstairs. According to the API 520 standard, workers exposed to 6.31 kW/m² of radiant heat that workers can withstand for 30 seconds were confirmed that it was possible to sufficiently escape from the inside.