• Journal of Digital Convergence
• /
• v.17 no.10
• /
• pp.93-102
• /
• 2019

This paper aims to set the priorities for the cybersecurity strategy of Cambodian government. To this end, we built a AHP research model by adopting 4 factors from the ITU national interests model and selecting 7 strategies from best practices of 8 countries leading the cyber security. Using a questionnaire, 19 experts evaluated Cambodia's cybersecurity strategy priorities. The key policy factors were evaluated in the order of homeland defense, economic welfare, value promotion and favorable world order. Their strategic alternatives were identified in the order of legislation, capacity building, and cyber attack prevention for critical infrastructure. This study will contribute to setting the strategic priorities and feasible action plans to strengthen Cambodia's cybersecurity capabilities.

• Journal of Industrial Convergence
• /
• v.20 no.3
• /
• pp.23-31
• /
• 2022

Recently, the importance of the role of the university information security department in nurturing security experts to defend against cyber attacks is increasing day by day. The current university security curriculum has a problem in that the proportion of theoretical education is high and the professionalism of practical education is relatively low. This study analyzed the recent educational programs of domestic and foreign security education institutions for the purpose of improving the practical ability of the Department of Security, designing a class model suitable for the core specialization process, and suggesting the direction. The proposed model improves the existing problems of basic class connection and security practice curriculum roadmap, and additionally explains the practice program of the five core specialized subjects. This study intends to contribute to the improvement of the quality of the curriculum and educational model of each university's security department.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.16 no.1
• /
• pp.1-7
• /
• 2023

Convolutional neural networks have already been applied to various fields beyond human visual processing capabilities in the image processing area. However, they are exposed to a severe risk of deteriorating model performance due to the appearance of adversarial attacks. In addition, defense technology to respond to adversarial attacks is effective against the attack but is vulnerable to other types of attacks. Therefore, to respond to an adversarial attack, it is necessary to analyze how the performance of the adversarial attack deteriorates through the process inside the convolutional neural network. In this study, the adversarial attack of the Alexnet and VGG11 models was analyzed using the population sparseness index, a measure of neuronal activity in neurophysiology. Through the research, it was observed in each layer that the population sparsity index for adversarial examples showed differences from that of benign examples.

• Convergence Security Journal
• /
• v.22 no.3
• /
• pp.25-32
• /
• 2022

Recently, the image processing industry has been activated as deep learning-based technology is introduced in the image recognition and detection field. With the development of deep learning technology, learning model vulnerabilities for adversarial attacks continue to be reported. However, studies on countermeasures against poisoning attacks that inject malicious data during learning are insufficient. The conventional countermeasure against poisoning attacks has a limitation in that it is necessary to perform a separate detection and removal operation by examining the training data each time. Therefore, in this paper, we propose a technique for reducing the attack success rate by applying modifications to the training data and inference data without a separate detection and removal process for the poison data. The One-shot kill poison attack, a clean label poison attack proposed in previous studies, was used as an attack model. The attack performance was confirmed by dividing it into a general attacker and an intelligent attacker according to the attacker's attack strategy. According to the experimental results, when the proposed defense mechanism is applied, the attack success rate can be reduced by up to 65% compared to the conventional method.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.18 no.2
• /
• pp.92-104
• /
• 2015

In order to analyze the impacts of climate change, a time and space integrated model was developed in this study using system dynamics and GIS. The model built was used to carry out a simulation on the inundation impact on A-gu of Busan Metropolitan city resulting from the sea level rise scenario of IPCC and storm surge, which is the worst case. Through this, the flooded area and population until 2100 were predicted. Also, the result and significance of each alternative was reviewed improving the model by establishing alternative scenarios of protection, accommodation and retreat as plans of reaction to sea level rise. The combination of system dynamics and GIS has advantages of how the diverse variables change until the target year can be traced and, accordingly, not only the results but also the processes of spatial change can be examined by calculating the value of change process at each time step. The synergy of this model presumed to be a foothold for solving problems which are becoming difficult to predict due to increase in uncertainty and complexity such as the support for decision making for urban resilience to natural disasters.

• Journal of Radiation Protection and Research
• /
• v.29 no.2
• /
• pp.73-90
• /
• 2004

The Reg. Guide 1.109 model was reviewed against its applicability to calculating radionuclide concentrations in agricultural products for operating nuclear facilities and an improved method was proposed. The model was so modified that the radionuclides deposited since the start of operation could be considered in assessing the root uptake. Translocation factors were introduced in the equation for calculating the concentrations in edible parts due to direct plant deposition. Values specific to Korea were set up for the input parameters of the modified model. The concentrations of $^{54}Mn,\;^{60}Co,\;^{90}Sr\;and\;^{137}Cs$ in rice seeds, Chinese cabbage and radish root were calculated for various hypothetical deposition histories using the Reg. Guide 1.109 model and the modified model with parameter values in the guide and those specific to Korea put in alternately. Through comparisons among the results, it could be expected that the use of the modified model with the input of parameter values specific to Korea would result In a more resonable and realistic assessment.

• Journal of Radiation Protection and Research
• /
• v.18 no.1
• /
• pp.9-24
• /
• 1993

The time-dependent radioecological model applicable to Korean environment has been developed in order to assess the radiological consequences following the short-term deposition of radionuclides in an accident of nuclear power plant. Time-dependent radioactivity concentrations in foodstuffs can be estimated by the model called 'KORFOOD' as well as time-dependent and time-integrated ingestion doses. Three kinds of critical radionuclides and thirteen kinds of foodstuffs were considered in this model. Dynamic variation of radioactivities were simulated by considering several effects such as deposition, weathering and washout, resuspension, root uptake, translocation, leaching, senescence, intake and excretion of soil by animals, intake and excretion of feedstuffs by animals, etc. The input data to the KORFOOD are the time of the year when the deposition occurs, the kinds of radionuclides and foodstuffs for estimation. The time-dependent specific activities in rice and the ingestion doses due to the consumption of all considered foodstuffs were calculated with deposition time using agricultural data-base in Kori region. In order to validate results of KORFOOD, the calculated results were compared with those by a leading German model, ECOSYS-87. The comparison of results shows good agreements within a factor of ten.

• Journal of Radiation Protection and Research
• /
• v.27 no.1
• /
• pp.21-26
• /
• 2002

For the consideration of the influence on radioactive contamination of foods due to rain during the release period of radionuclides in a nuclear accident, the previous dynamic food chain model was improved. Wet interception coefficients for the agricultural plants were derived as a function of radionuclide and rainfall amount, and mathematical formula of the model was also re-established. In the results for the same time-integrated radioactive concentrations on the ground, radioactive contamination of foods decreased greatly by rainfall, and it decreased dramatically according to increasing rainfall amount. It means that predictive contamination in foods using the previous dynamic food chain model, in which dry interception to the agricultural plants is only considered, can be overestimated. Among radionuclides considering in this study ($^{137}Cs,\;^{90}Sr,\;^{131}I$), influence of rainfall for food contamination was the most sensitive to $^{131}I$, and the least sensitive to $^{90}Sr$.

• Journal of Radiation Protection and Research
• /
• v.25 no.4
• /
• pp.233-239
• /
• 2000

The sensitivity analysis of input parameters was Performed fer an ingestion dose assessment model (U. S. NRC's Regulatory Guide 1.109 model) from routine releases of radionuclides. In this study, three kinds of typical Korean foodstuffs (rice, leaff vegetables, milk) and two kinds of radionuclides $(^{l37}Cs,\;^{131}I)$ were considered. The values of input parameters were sampled using a Latin hypercube sampling technique based on Monte Carlo approach. Sensitivity indices, which represent the influence or the importance of input parameters for predictive results, were quantitatively expressed by the partial rank correlation coefficients. As the results, the ratio of the interception fraction to the yield of agricultural plants and the human consumption rate were sensitive input parameters for the considered foodstuffs and radionuclides. Additionally, in case of milk, the transfer factor of radionuclides from animal intake to milk and the daily intake rate of feedstuffs were sensitive input parameters. The weathering removal half-life and the delay time from food production to human consumption were relatively sensitive for $^{137}Cs$ and $^{131}I$ depositions, respectively.

• Journal of Radiation Protection and Research
• /
• v.30 no.3
• /
• pp.99-105
• /
• 2005

A model for evaluating radioactive contamination in the urban environment, named METRO-K, was developed as a basic step for accident consequence analysis in case of an accidental release. The three kind of radionuclides $(^{137}Cs,\;^{106}Ru,\;^{131}I)$ and the different chemical forms of iodine (particulate, organic and elemental forms) are considered in the model. The radioactive concentrations are evaluated for the five types of surface (roof, paved road, wall, lawn/soil, tree) as a function of time. Using the model, the contaminative impacts of the surfaces were intensively investigated with respect to with and without precipitation during the measurement periods of radionuclides in air. In addition, a practical application study was conducted using $^{137}Cs$ concentration in air and precipitation measured in an European country at the Chernobyl accident. As a result precipitation was an influential factor in surface contamination. The degree of contamination was strongly dependent on the types of radionuclide and surface. Precipitation was more influential in contamination of $^{137}Cs$ than that of $^{131}I$ (elemental form).