• Nuclear Engineering and Technology
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• v.55 no.9
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• pp.3409-3416
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• 2023

Licensing the next-generation of nuclear reactor designs requires extensive use of Modeling and Simulation (M&S) to investigate system response to many operational conditions, identify possible accidental scenarios and predict their evolution to undesirable consequences that are to be prevented or mitigated via the deployment of adequate safety barriers. Deep Learning (DL) and Artificial Intelligence (AI) can support M&S computationally by providing surrogates of the complex multi-physics high-fidelity models used for design. However, DL and AI are, generally, low-fidelity 'black-box' models that do not assure any structure based on physical laws and constraints, and may, thus, lack interpretability and accuracy of the results. This poses limitations on their credibility and doubts about their adoption for the safety assessment and licensing of novel reactor designs. In this regard, Physics Informed Neural Networks (PINNs) are receiving growing attention for their ability to integrate fundamental physics laws and domain knowledge in the neural networks, thus assuring credible generalization capabilities and credible predictions. This paper presents the use of PINNs as surrogate models for accidental scenarios simulation in Nuclear Power Plants (NPPs). A case study of a Loss of Heat Sink (LOHS) accidental scenario in a Nuclear Battery (NB), a unique class of transportable, plug-and-play microreactors, is considered. A PINN is developed and compared with a Deep Neural Network (DNN). The results show the advantages of PINNs in providing accurate solutions, avoiding overfitting, underfitting and intrinsically ensuring physics-consistent results.

• International Journal of Computer Science & Network Security
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• v.23 no.1
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• pp.153-163
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• 2023

This study is situated in the context of intelligent transport systems, where in-vehicle devices assist drivers to avoid accidents and therefore improve road safety. The vehicles present in a given area form an ad' hoc network of vehicles called vehicular ad' hoc network. In this type of network, the nodes are mobile vehicles and the messages exchanged are messages to warn about obstacles that may hinder the correct driving. Node mobilities make it impossible for inter-node communication to be end-to-end. Recognizing this characteristic has led to delay-tolerant vehicular networks. Embedded devices have small buffers (memory) to hold messages that a node needs to transmit when no other node is within its visibility range for transmission. The performance of a vehicular delay-tolerant network is closely tied to the successful management of the nodes' transit buffer. In this paper, we propose a message transit buffer management model for nodes in vehicular delay tolerant networks. This model consists in setting up, on the one hand, a policy of dropping messages from the buffer when the buffer is full and must receive a new message. This drop policy is based on the concept of intermediate node to destination, queues and priority class of service. It is also based on the properties of the message (size, weight, number of hops, number of replications, remaining time-to-live, etc.). On the other hand, the model defines the policy for selecting the message to be transmitted. The proposed model was evaluated with the ONE opportunistic network simulator based on a 4000m x 4000m area of downtown Bouaké in Côte d'Ivoire. The map data were imported using the Open Street Map tool. The results obtained show that our model improves the delivery ratio of security alert messages, reduces their delivery delay and network overload compared to the existing model. This improvement in communication within a network of vehicles can contribute to the improvement of road safety.

• Korean Security Journal
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• no.38
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• pp.83-107
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• 2014

As a part of school safety network construction project, a system of school marshal in Seoul-si and a project of academy safety guard in other regions are on the way of improvement. But, the crimes in and around the school, occurring frequently, are not solved easily, as this study points out. The effective improvement way of school safety network construction project is as followings. First, to enforce assistant-class school safety teacher system in order to nurture and educate experts in school safety, as a systematic support for strengthening occupational professionalism. Second, to enforce school safety network construction projects for construct circumstances through legal fix of school safety CPTED to make students free from crimes. This study looks into the real status and problem of school safety networks, and suggests system of school safety teacher and a legal enactment of CPTED, as systematic and a planed school safety countermeasure, not temporary.

• Journal of Advanced Navigation Technology
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• v.16 no.6
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• pp.920-926
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• 2012

In this paper, marine accidents recently happened in Korea and Japan for 5 years, especially through the analysis of accident characteristics for fishing vessels, including small vessels were analyzed. Also propose a new maritime safety communication network in the form of a comprehensive considering the wave propagation characteristics and operational characteristics of radio communication equipments should be installed in the vessel through comprehensive analysis of the regulation according to the radio equipment and the ship's location identification device installation and operation.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.1
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• pp.48-55
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• 2009

In order to keep safe driving conditions under road networks, there are several formations such as road structure, road surface condition, traffic occupancy and supplement of an accurate information of traffic status ahead To support safe-driving on each road formation, each formation is supplied with various information to help the driver. However, in some cases like rapid status change at local-scale geography, traffic information systems often displays insufficient information because of the lack of information correlation. In order to accurately aware the driver, all road formation must be in sync. It is important to supply accurate information to the driver because this information directly impacts the drivers on the road. This paper discusses the amber information to keep the least safety driving over road formations including tunnels and bridges. This paper also will propose the informations for safe-driving conditions, information linkage on the road and rule-base safety information, as ITS technology, being displayed for all drivers under the worst weather conditions.

• Journal of the Korea Safety Management & Science
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• v.7 no.3
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• pp.97-108
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• 2005

The issue of using information system to ensure competitive power in the market is rising. The outsourcing methods that entrust activities of information system of companies to other expert agencies are increasing as the enterprises make a lot of efforts to put their resources to their heart of business in the process of adopting information system. Recently, ASP (Application Service Provider) as new information technology outsourcing method appears due to development of network technology and spreading of peculating software. ASP defines as a software leasing service which is supplied through networks instead of purchasing application software with high price. For successful implementation of ASP, it is necessary to develop a certification program to ensure safety and reliability of ASP. This paper provides the safe and reliable certification program for ASP. In order to develop it, the critical issues related to service quality and certification of ASP are identified and then evaluation methodology for ASP certification program is proposed. This paper presents application certification as the part of ASP certification program.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.612-617
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• 2005

Safety of railway systems is made by understanding causes and process of railway accidents and grasping contents of a many of accidents. Now, Being carried out a research and analysis about an extensive areas(the whole country, the metropolitan area, the five metropolitan cities, the city of three hundred thousands and over of people) and field, thereafter the National Transportation (Railway) Database has been constructed and developed to prepare the base that reduced an overlapping survey using a standardized-material offer. A purpose of this research is to derive plans to apply National transport DB including information in the field of transportation systems to domestic railway safety management. The research analyses the present conditions of establishing national transport DB, and reviews problems when that use to railway system. As being based in this, the research derived definitions and using plans of layers available to use, and plans of establishing and systematizing information for desirable railway network.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.10a
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• pp.144-153
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• 2006

In order to take TC forecasts from different observatories into consideration, and make quantitative assessment and analysis for avoiding TC routes from the view of safety and cost, a new safe-economic decision making method of TC avoidance routing on ocean was put forward. This model is based on combining forecast of TC trace based on neural networks, technical method to determine the future TC wind and wave fields, technical method of fuzzy information optimization, risk analysis theory, and meteorological-economic decision making theory. It has applied to the simulation of MV Tianlihai's shipping on ocean. The result shows that the model can select the optimum plan from 7 plans, the selected plan is in accordance with the one selected by experienced captains.

• Proceedings of the KIEE Conference
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• 2009.04b
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• pp.186-188
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• 2009

Safety-critical systems related to the railway communications are currently undergoing changes. Mechanical and electro-mechanical devices are being replaced by programmable electronics that are often controlled remotely via communication networks. Therefore designers and operators now not only have to contend with component failures and user errors, but also with the possibility that malicious entities are seeking to disrupt the services provided by theirs systems. This paper discusses the safety strategies employed in the railway communications and proposes a security mechanism for Korean railway communication system.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.13-18
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• 2008

The 2005 west off Fukuoka earthquake with Mjma 7.0 occurred in the vicinity of Fukuoka city with 1.4 million populations, which had been regarded as rather seismically inactive in Japan. The strong motion records by K-net indicated PGV of 64 cm/s in Fukuoka city and some condominium buildings sustained extensive non-structural damages. In this study, we conducted a questionnaire survey for residents of 8 condominium buildings located in the downtown area of Fukuoka city after the earthquake. The results indicate that damaged nonstructural walls and distorted doors disrupted evacuation route for many occupants, and furniture and content damage on upper floors became severer resulting in higher rates of human casualty. Earthquake preparedness for indoor safety was raised after the earthquake, though further safety measures can be advised. In the phase of post-earthquake emergency and restoration period, residents' management organizations play important roles, so that neighborhood activities to promote communication networks are important in urban environment with aging population.