• Nuclear Engineering and Technology
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• 제55권6호
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• pp.2034-2046
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• 2023

Industrial control systems in nuclear facilities are facing increasing cyber threats due to the widespread use of information and communication equipment. To implement cyber security programs effectively through the RG 5.71, it is necessary to quantitatively assess cyber risks. However, this can be challenging due to limited historical data on threats and customized Critical Digital Assets (CDAs) in nuclear facilities. Previous works have focused on identifying data flows, the assets where the data is stored and processed, which means that the methods are heavily biased towards information security concerns. Additionally, in nuclear facilities, cyber threats need to be analyzed from a safety perspective. In this study, we use the system theoretic process analysis to identify system-level threat scenarios that could violate safety constraints. Instead of quantifying the likelihood of exploiting vulnerabilities, we quantify Security Control Measures (SCMs) against the identified threat scenarios. We classify the system and CDAs into four consequence-based classes, as presented in NEI 13-10, to analyze the adversary impact on CDAs. This allows for the ranking of identified threat scenarios according to the quantified SCMs. The proposed framework enables stakeholders to more effectively and accurately rank cyber risks, as well as establish security and response strategies.

• International Journal of Computer Science & Network Security
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• 제23권11호
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• pp.149-161
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• 2023

Internet of Things (IoT) is a relatively new concept that has gained immense popularity in a short period of time due to its wide applicability in making human life more convenient and automated. As an illustration: the development of smart homes, smart cities, etc. However, it is also accompanied by a substantial number of risks and flaws. IoT makes use of low-powered devices, so secure, less time-consuming and energy-intensive transmission (routing) of messages due to the limited availability of energy is one of the many and most significant concerns for IoT developers. The following paper presents a trust-based routing scenario for the Internet of Things (IoT) that exploits the past transmission record from the cupcarbon simulator's log files. Artificial Neural Network is used to quantify knowledge of trust, calculate the value of trust, and share this information with other network devices. As a human behavioural pattern, trust provides a superior method for making routing decisions. If there is a tie in the trust values and no other path is available, the remaining battery power is used to break the tie and make a forwarding decision; this is also seen as a more efficient use of the available resources. The proposed algorithm is observed to have superior energy consumption and routing decisions compared to conventional routing algorithms, and it improves the communication pattern.

• 한국농공학회논문집
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• 제64권1호
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• pp.1-13
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• 2022

In Korea, attention is being paid to the use of renewable energy in the livestock industry, and Ground Source Heat Pump (GSHP), which is advantageous for temperature control, is considered as one of the ways to reduce the use of fossil fuels. But GSHP is expensive to install, which proper capacity calculation is required. GSHP capacity is related to its maximum energy load. Energy loads are affected by climate characteristics and time, so dynamic analysis is required. In this study, the optimal capacity of GSHP was calculated by calculating the heating and cooling load of pig farms using BES (Building Energy Simulation) and economic analysis was performed. After designing the inside of the pig house using TRNSYS, one of the commercial programs of the BES technique, the energy load was calculated based on meteorological data. Through the calculated energy load, three heating devices and GSHP used in pig farms were analyzed for economic feasibility. As a result, GSHP's total cost of ownership was the cheapest, but the installation cost was the highest. In order to reduce the initial cost of GSHP, the capacity of GSHP was divided, and a scenario was created in which some of it was used as an auxiliary heating device, and economic analysis was conducted. In this study, a method to calculate the proper capacity of GSHP through dynamic energy analysis was proposed, and it can be used as data necessary to expand the spread of GSHP.

• 한국태양에너지학회 논문집
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• 제32권1호
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• pp.32-39
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• 2012

New and renewable energy systems(solar thermal system, photovoltaic system, geothermal system, wind power system) are environmentally friendly technologies and these in South Korea are very important measures to reduce greenhouse-gas(GHG) and to push ahead with Green Growth. The purpose of this paper is to analyze GHG mitigation potential by distribution of solar thermal system in housing sector with bottom-up model called 'Long-range Energy Alternative Planning system'. Business as usual(BAU) was based on energy consumption characteristic with the trend of social-economic prospects and the volume of housing. The total amount of GHG emission of BAU was expected to continuous increase from 66.0 million-ton $CO_{2e}$ in 2007 to 73.1 million-ton $CO_{2e}$ in 2030 because of the increase of energy consumption in housing. The alternative scenario, distribution of solar thermal system in housing sector had GHG mitigation potential 1.54 million-ton $CO_{2e}$ in 2030. The results of this study showed that new and renewable energy systems made a contribution of reducing the use of fossil fuel and the emission of greenhouse-gas in building.

• 한국해양환경ㆍ에너지학회지
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• 제13권1호
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• pp.60-67
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• 2010

무인도서의 지속가능한 이용을 보장하기 위해서는 이용 개발계획을 수립할 때 무인도서 생태계의 높은 가치를 충분히 고려하고, 이용 개발 행위가 이루어지기 전에 환경수용력을 먼저 평가할 필요가 있다. 이 연구에서는 에머지 개념과 방법론을 이용하여 무인도서인 인천광역시 옹진군 소재 선갑도의 생태계 가치와 환경수용력을 평가하였다. 선갑도의 에머지 평가경계는 육지부뿐만 아니라 '무인도서의 보전 및 관리에 관한 법률'의 무인도서 관리범위를 따라 만조수위선으로부터 1 km이내의 해역까지 포함하였다. 선갑도 생태계로 유입하는 재생가능 에머지량은 $1.04{\times}10^{20}$ sej/yr로, 해면부의 조석 에머지가 가장 중요하였다. 선갑도의 가치는 연간 299억 Em￦으로 높게 나타났다. 선갑도 육지부와 해면부의 에머지 기여도를 모두 포함하여 환경수용력을 계산한 결과, 우리나라 평균 수준개발 시나리오의 경우 6,586명, 장기적 지속가능성 시나리오의 경우 2,337명이었다. 그러나 선갑도 육지부가 공급하는 에머지만 고려할 경우 환경수용력은 우리나라 평균수준 개발을 가정할 경우 14명, 장기적 지속가능성을 고려할 경우 5명에 불과하였다. 따라서 선갑도를 포함한 무인도서의 생태계 가치를 유지하고 무인도서 이용의 지속성을 보장하기 위해서는 이용 개발계획 수립단계에서부터 환경수용력을 고려하도록 제도화 할 필요가 있다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권8호
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• pp.1805-1824
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• 2013

Recently, the use of wireless body area networks (WBAN) has been increasing rapidly in medical healthcare applications. WBANs consist of smart nodes that can be used to sense and transmit vital data such as heart rate, temperature and ECG from a human body to a medical centre. WBANs depend on limited resources such as energy and bandwidth. In order to utilise these resources efficiently, a very well organized medium access control (MAC) protocol must be considered. In this paper, a new, adaptive and energy-efficient MAC protocol, entitled isMAC, is proposed for WBANs. The proposed MAC is based on multi-channel communication and aims to prolong the network lifetime by effectively employing (i) a collision prevention mechanism, (ii) a coordinator node (WCN) selection algorithm and (iii) a transmission power adjustment approach. The isMAC protocol has been developed and modelled, by using OPNET Modeler simulation software. It is based on a networking scenario that requires especially high data rates such as ECG, for performance evaluation purposes. Packet delay, network throughput and energy consumption have been chosen as performance metrics. The comparison between the simulation results of isMAC and classical IEEE 802.15.4 (ZigBee) protocol shows that isMAC significantly outperforms IEEE 802.15.4 in terms of packet delay, throughput and energy consumption.

• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.241-257
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• 2020

The rapid proliferation of oil/gas drilling and wind turbine installations with jack-up rig-formed structures increases structural safety requirements, due to the greater risks of operational collisions during use of these structures. Therefore, current industrial practices and regulations have tended to increase the required accidental collision design loads (impact energies) for jack-up rigs. However, the existing simplified design approach tends to be limited to the design and prediction of local members due to the difficulty in applying the increased uniform impact energy to a brace member without regard for the member's position. It is therefore necessary to define accidental load estimation in terms of a reasonable collision scenario and its application to the structural response analysis. We found by a collision probabilistic approach that the kinetic energy ranged from a minimum of 9 MJ to a maximum 1049 MJ. Only 6% of these values are less than the 35 MJ recommendation of DNV-GL (2013). This study assumed and applied a representative design load of 196.2 MN for an impact load of 20,000 tons. Based on this design load, the detailed design of a leg structure was numerically verified via an FE analysis comprising three categories: linear analysis, buckling analysis and progressive collapse analysis. Based on the numerical results from this analysis, it was possible to predict the collapse mode and position of each member in relation to the collision load. This study provided a collision strength assessment between attendant vessels and a jack-up rig based on probabilistic collision scenarios and nonlinear structural analysis. The numerical results of this study also afforded reasonable evaluation criteria and specific evaluation procedures.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전력기술부문
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• pp.291-293
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• 2003

Energy markets of the Northeast Asia countries and in particular South Korea are perspective enough from the standpoint of export of energy resources from Russia. South Korea Power System has been rapidly growing. However, recently it has been confronted with difficulties in regard to constructing new Power Stations and especially Hydro Power Plants. Therefore it is mutually beneficial to build electric tie to South Korea in order to use highly effective Power of Northeast Asia. In this paper, we describe the maximum available transmission power through interconnected line without loss of stability in power system. For this simulation, the AC transmission system is assumed appropriate for this preliminary study. The transmission system will pass through territory of North Korea and connect to 765 kV Network near Seoul with long distance.

• 한국기후변화학회지
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• 제9권1호
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• pp.91-102
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• 2018

The Korean government submitted the Intended Nationally Determined Contributions (INDC) to UNFCCC which aims to reduce 37% greenhouse gas emission for the opportunity of developing new energy industry and industry innovation by 2030 compared with Business-As-Usual scenario taking into account its international responsibilities and hosting headquarters of Green Climate Fund (GCF) secretariat. The 37% reduction is composed of 25.7% in the domestic markets and 11.3% in the international carbon markets. To achieve the reduction target in the international carbon market mechanisms, it must use the linkage of international carbon markets and develop new renewable energy technology for CDM and ODA. Finally, it must improve carbon capture storage (CCS) technology and establish domestic CCS institutional systems as soon as possible. And, it must activate CCS information exchange for the international cooperation on UNFCCC movement.

• 한국인터넷방송통신학회논문지
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• 제13권5호
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• pp.77-83
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• 2013

현재, 조명제어와 관리기술의 한계점은 유선으로 인한 시설비 과다, 운영의 어려움, 에너지낭비이다. 이를 해결하기 위해 조명기기에 무선네트워크 기능이 탑재된 스마트 조명 정보 시스템을 복합적으로 수행하기위한 통신 및 관리 소프트웨어가 필요하다. 본 논문에서는 LED조명의 전력량 모니터링을 통해 에너지 절감을 위한 기술을 개발하고, 이 기술을 융합하기 위해 전력 에너지 정보시스템 LEIS(Lighting Energy Information System)을 개발 했다. LEIS는 센서에 의해 지그비 메쉬망을 통해 수집된 전력 데이터를 모니터링하고 제어하는 시스템으로 조명의 사용에너지 정보를 사용자에게 시각화하여 보여준다. 이 시스템은 LEM(Lighting Energy Metering)의 정보를 바탕으로 한 전력정보 데이터베이스 및 LEIS 웹어플리케이션으로 구성되고 LEIS를 통해 에너지를 최적화하여 제어할 수 있는 시나리오 기능을 제공한다.