• Journal of the Korean Institute of Gas
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• v.4 no.3 s.11
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• pp.1-8
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• 2000

It is required that gas accidents should be managed carefully as the consumption of fuel gas increases and high pressure gas process becomes more complex, which may cause a catastrophic accident. Factors to cause accidents were investigated through a systematic analysis of gas accidents between 1995 and 1998, which could be applied to prepare countermeasures to reduce gas accidents. As a result, it was suggested that the effective countermeasures to gas accidents should be kept applied, while new countermeasures were suggested in the field of increasing or not-decreasing number of accident. Totally 2,027 of accidents were reported during this term, and were found to decrease by about $12\%$ every year from 1996. The number of fuel gas such as LPG and city gas accident took up $96\%$, and most of accidents occurred at end-user's facility such as residential house and restaurant business. According to the kind of gas and facility, trend of accident by cause varies, while dominant causes are defective installation, appliance failure, or user's carelessness. Intentional accidents by fuel gas was excluded in this study because of its occurring mechanism and will be analyzed further elsewhere, although it took up $15\%$ and increased by $38\%$ every year.

• Journal of the Korean Institute of Gas
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• v.4 no.2 s.10
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• pp.46-51
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• 2000

It is required that fuel gas accidents should be managed carefully along with the increase of fuel gas consumption. Factors to cause accidents were investigated through a systematic analysis of gas accidents during recent 4 years, which could be applied to prepare countermeasures to reduce gas accidents. The thawing season is found to be weak to gas accidents, showing a slightly higher rate of accident occurring than average. During this term although the number of LPG accident is similar to that of yearly average, countermeasures are required for LPG facilities since the portion of accident is large; in detail, user's carelessness, defective facility, or instrument failure are major causes. The number of city gas accident facility is larger than that of yearly average; particularly, defective facilities, third-party work, and appliance failure are major causes. As a result, countermeasures have been suggested for the accident of large portion or above yearly average.

• Journal of the Korean Institute of Gas
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• v.24 no.3
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• pp.27-32
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• 2020

For preventing accident, the risk analysis about gas facilities has been more important since many gas facilities be superannuated. Especially, deriving and simulating risk is very important for preventing and corresponding accidents by means of specific analysis method in complex gas facilities. However, many studies have been not enough not yet in order to derive and simulate risk considering various situations. This paper aims to propose deriving and analyzing risk method around limited area of complex gas facilities. Our study proposes total risk analysis that is composed four methods with individual point of view. The risk analysis system based on RiskMAP immediately informs users changes of e risk in zones according to the status, work and surrounding conditions of the facility. The proposed methods in this research are implemented as software algorithm and applied to risk analysis system using RiskMAP in conjunction with IoT and GPS.

• Journal of Advanced Navigation Technology
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• v.17 no.6
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• pp.672-678
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• 2013

In this paper, with the development of Information technology, application service between IT and traditional industry has been on the rise. And there are many on-going discussions actively regarding the Air quality system based on wireless sensor network which monitor and control the aircraft environment automatically and manually with the application service of detecting harmful gas. In this paper, operation program constitute the administrator monitoring device, which collects data from sensor node of wireless sensor network and sensor node and transmits environment information to display and server. Also for remote monitoring, user operation program constitutes based on PC/smartphone. Under this, the harmful gas which is made in aircraft life is measured. Real time monitoring system based on wireless sensor network is designed and realized.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.6
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• pp.82-94
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• 2008

The purpose of web-sensor is to transmit the measured sensor data and the related information to remote user. Since the user exists at remote place, the sensor information must be trustworthy, and the diagnosis for sensors should be easy to handle. To make sure of these issues, IEEE 1451 for smart sensor had been presented in the past. This research proposes the smart web sensor. The proposed smart web sensor is based on IEEE 1451.0, therefore most of the sensor interfaces are able to be used, and could realize the smart sensor by using TEDS information. Also it has the user-friendly web-service by using XML so that the remote user can handle easily the every possible information related to sensor. This research presents reference model for smart web sensor, and to prove how valuable it is, web-service using gas sensor is implemented.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.7
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• pp.1060-1070
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• 2022

With the development of information technology, the size of the system has become larger and diversified, and the existing role-based access control has faced limitations. Blockchain technology is being used in various fields by presenting new solutions to existing security vulnerabilities. This paper suggests efficient role-based access control in a blockchain where the required gas and processing time vary depending on the access frequency and capacity of the storage. The proposed method redefines the role of reusable units, introduces a hierarchical structure that can efficiently reflect dynamic states to enhance efficiency and scalability, and includes user-centered authentication functions to enable cryptocurrency linkage. The proposed model was theoretically verified using Markov chain, implemented in Ethereum private network, and compared experiments on representative functions were conducted to verify the time and gas efficiency required for user addition and transaction registration. Based on this in the future, structural expansion and experiments are required in consideration of exception situations.

• Journal of the Korean Electrochemical Society
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• v.8 no.4
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• pp.155-161
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• 2005

In this paper, commercial CFD program FLUENT v5.3 is used for simulation of MCFC stack. Besides using conservation equations included in FLUENT by default, mass change, mole fraction change and heat added or removed due to electrochemical reactions and water gas shift reaction are considered by adding several equations using user defined function. The stacks calculated are 6 and 25 kW class coflow stack which are composed of 20 and 40 unit cells respectively. Simulation results showed that pressure drop took place in the direction of gas flow, and the pressure drop of cathode side is more larger than that of anode side. And the velocity of cathode gas decreased along with the gas flow direction, but the velocity of anode gas increased because of the mass and volume changes by the chemical reactions in each electrodes. Simulated temperature profile of the stack tended to increase along with the gas flow direction and it showed similar results with the experimental data. Water gas shift reaction was endothermic at the gas inlet side but it was exothermic at the outlet side of electrode respectively. Therefore water gas shift reaction played a role in increasing temperature difference between inlet and outlet side of stack. This results suggests that the simulation of large scale commercial stacks need to consider water gas shift reaction.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.1169-1172
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• 2011

본 연구는 고가의 인프라 구축이라는 제약 때문에 현재까지 기초적인 수준에 머물러있는 홈 네트워크의 문제점을 극복하고자 제안된 스마트폰 중심의 개인환경서비스(PES : Personal Environment Service)를 연구하였다. 개인환경서비스는 스마트폰과 무선랜, 블루투스 등의 모듈이 탑재된 가전기기와 근거리 무선통신으로 사용자의 선호도를 저장하고 있는 프로파일을 교환하여 가전기기를 자동으로 설정해 주며 프로파일은 서비스 서버에도 전송되어 지속적으로 갱신, 사용자에게 편리한 생활을 제공해 준다. 본 연구는 이러한 스마트폰 중심의 개인환경서비스의 데모 시스템 구조 및 시연 시스템을 구축하였다. 데모시스템의 스마트폰 플랫폼은 구글 사의 안드로이드 2.2 (Froyo) 버전이며, 지능형 가전기기와는 블루투스 통신을 통해 사용자와 서비스 프로파일을 교환한다. 가전기기는 PC, 난방기기, 가스렌지, TV, 라디오 총 5가지를 구현하였는데 실제 가전기기를 구현할 수 없는 한계로 인해 PC를 제외한 가전기기는 블루투스 임베디드 보드에 LCD 디스플레이를 설치한 모의(pseudo) 가전기기로 대체하였다. 스마트폰에 저장되어 있는 사용자 프로파일은 각각의 가전기기별 선호도를 환경설정을 통해 설정할 수 있게 하였고, 선호도를 설정하면 가전기기는 블루투스 통신으로 스마트폰의 사용자 프로파일을 전송받아 자동 설정해 준다. 서비스 서버는 스마트폰과 가전기기의 모든 로그를 전송받아 패턴분석 과정을 거쳐 사용자의 프로파일을 자동으로 설정해주어서 사용자는 개인에게 최적화된 생활환경을 제공받게 된다. 개인환경서비스는 현재 표준화 규격 개발을 위해 제조업체, 이동통신사, 연구소, 대학교 등에서 활발히 연구 중에 있으며, 향후에는 현재까지 개발된 데모 시스템을 토대로 프로토콜을 연구, 수립하여 표준화 규격 개발에 기여할 예정이다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.9-14
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• 2018

The function of gas springs is based on the compression of a gas. They are used in a wide variety of industries, and demand for them is increasing. Gas springs can be divided into compression and extension springs. Extension springs have not been studied much in relation to control of the piston speed, unlike compression springs. In this study, the magnitude of the piston rebound pressure was theoretically predicted by calculating the pressure loss in a double-cylinder extension gas spring. Numerical simulations of the piston behavior were carried out for small and large amounts of friction between the piston and the cylinder. FLUENT was used for the simulation with a 6-DOF model and UDF to simulate the behavior of the piston. The calculation regions of the front and rear of the piston were separated, and different types of grids were generated in the regions to implement a dynamic mesh using only a layering method. The results show that the piston returns with the target speed in both cases. However, the patterns of the piston behavior reaching the final speed are different.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.391-394
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• 2012

Recently, for appling to industrial engines to CRDI diesel engine to meet enhanced emission regulatory standards in native and foreign, ECU that be controlled only automaker develop engine control algorithm that adjust injection timing and injection as user's need and use testing, verification for engine performance and emissions reduction. For development only CRDI diesel engine emulator, using CKP and CMP sensor performance property of CRDI engine control ECU input element, in this paper, there determine the diesel knocking and propose design methodology of engine balance correction algorithm design of the correction algorithm. And there propose efficient Improvement for fuel efficiency increasing and reduction of emissions.