• Journal of Convergence for Information Technology
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• v.9 no.3
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• pp.134-139
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• 2019

As the development of modern society progresses rapidly, the technologies of society as a whole are progressing and becoming more advanced. Especially in the field of security, more sophisticated and intelligent attacks are being created. Meanwhile, damaging situations are becoming several times larger than before Therefore, it is necessary to re-classify and enhance the existing classification system. It is required to minimize the intrusion damage by actively responding to intelligent intrusions by applying this classification scheme to currently operating intrusion detection systems. In this paper, we analyze the intrusion type caused by intelligent attack We propose a new classification scheme for intrusion situations to guarantee the service safety, reliability, and availability of the target system, We use this classification model to lay the foundations for the design and implementation of a smart intrusion cognitive system capable of early detection of intrusion, the damages caused by intrusion, and more collections active response.

• Journal of the Korea Society of Computer and Information
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• v.28 no.7
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• pp.47-55
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• 2023

This paper presents a method for predicting the threat index of combat systems using Gradient Boosting Regressors and Support Vector Regressors among machine learning models. Currently, combat systems are software that emphasizes safety and reliability, so the application of AI technology that is not guaranteed to be reliable is restricted by policy, and as a result, the electrified domestic combat systems are not equipped with AI technology. However, in order to respond to the policy direction of the Ministry of National Defense, which aims to electrify AI, we conducted a study to secure the basic technology required for the application of machine learning in combat systems. After collecting the data required for threat index evaluation, the study determined the prediction accuracy of the trained model by processing and refining the data, selecting the machine learning model, and selecting the optimal hyper-parameters. As a result, the model score for the test data was over 99 points, confirming the applicability of machine learning models to combat systems.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.308-309
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• 2022

The Ministry of Oceans and Fisheries is providing maritime safety services using combine limited artificial intelligence technologies through the operation of the Korean e-Navigation service, and research is needed to improve reliability and quality to secure the competitiveness of the system. However, linking real-time operating systems requires a separate system configuration that can be linked after processing personal information security with minimal performance impact. To solve this problem, this study will make a basic design of a big-data maritime information gateway system of the Korean e-Navigation service that minimizes the impact of performance and reflects the security of personal information.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.2
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• pp.165-171
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• 2013

Due to the difficulty in considering dynamic load in the view point of a computer resource and computing time, it is common that external load is assumed as ideal static loads. However, structural analysis under static load cannot guarantee the safety of design of the structures under dynamic loadings. Recently, the systematic method to construct equivalent static load from the given dynamic load has been proposed. Previous study has calculated equivalent static load through the optimization procedure under displacement constraints. However, previously reported works to distribute equivalent static load were based on ad-hoc methods. Improper selection of equivalent static loading positions may results in unreliable prediction of structural design. The present study proposes the selection method of the proper locations of equivalent static loads to dynamically applied loads when we consider transient dynamic structural problems. Moreover, it is appropriate to take into account the stress constraint as well as displacement constraint condition for the safety design. But the previously reported studies of equivalent static load design methods considered only displacement constraint conditions but not stress constraint conditions. In the present study we consider not only displacement constraint but also stress constraint conditions. Through a few numerical examples, the efficiency and reliability of proposed scheme is verified by comparison of the equivalent stress between equivalent static loading and dynamic loading.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.5
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• pp.15-27
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• 2022

An omnidirectional VR treadmill is a highly-immersive walking simulator that allows identical body movements, such as walking, running, and sitting. However, the operation difficulty of an omnidirectional VR treadmill may cause data reliability problems. Therefore, this study aims to verify the effectiveness of a VR treadmill by comparing the ability to orient in the real and virtual worlds spatially. For this purpose, a rotating and searching path experiment was conducted with participants. This experiment showed that there was no statistically significant difference in the ability of the participants to orient in the real and virtual worlds spatially. In addition, the omnidirectional VR treadmill requires an adaptation time for the users due to the difficulty in the treadmill operation. However, there was no significant difference in the difficulty felt by the participants according to the adaptation time. Hence, these findings supported the possibility of collecting realistic walking data without safety concerns through an omnidirectional VR treadmill. Furthermore, this treadmill could be used in future research to solve problems directly related to pedestrian safety, such as the interaction between vehicles and pedestrians.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.5
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• pp.407-414
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• 2024

This study analyzed the spatiotemporal errors and limitations of LDAPS-based rainfall forecast data used in coastal ocean numerical models and verified their reliability by comparing them with the rainfall data for 2020 from three rain gauges located around Jinhae Bay, South Korea. The results indicated that although LDAPS-based rainfall data generally reproduced long-term trends, they exhibited significant discrepancies in short-term variations. The quantitative error in annual rainfall was 197.5 mm, which increased to 285.4 mm for summer, indicating that the difference in the cumulative rainfall prediction increases for seasons with high rainfall variability. Furthermore, the rainfall-time predictions exhibited a temporal delay of approximately 8 h, suggesting that temporal errors in the LDAPS-based rainfall data could significantly reduce the accuracy of coastal environment predictions. The indiscriminate use of these data, which fail to accurately reflect coastal rainfall, could lead to serious issues in predicting coastal environmental changes caused by pollutants or extreme rainfall events. Therefore, to appropriately use LDAPS-based rainfall data, it is necessary to improve their accuracy through comprehensive verifications and further refinements.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.4
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• pp.437-442
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• 2010

Flow-accelerated corrosion (FAC) leads to thinning of steel pipe walls that are exposed to flowing water or wet steam. From experience, it is seen that FAC damage to piping at fossil and nuclear plants can result in outages that require expensive repairs and can affect plant reliability and safety. CHECWORKS have been utilized in domestic nuclear plants as a predictive tool to assist FAC engineers in planning inspections and evaluating the inspection data so that piping failures caused by FAC can be prevented. However, CHECWORKS may be occasionally ignore local susceptible portions when predicting FAC damage in a group of pipelines after constructing a database for all the secondary side piping in nuclear plants. This paper describes the methodologies that can complement CHECWORKS and the verifications of CHECWORKS prediction results using numerical analysis. FAC susceptible locations determined using CHECWORKS for two pipeline groups of a nuclear plant was compared with determined using the numerical-analysis-based FLUENT.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.2
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• pp.156-164
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• 2016

Qualification model(QM) of main payloads including concentrating photovoltaic system using fresnel lens, heating wire cutting type shockless holding and release mechanism, and MEMS-based solid propellant thruster have been developed for the STEP Cube Lab.(Cube Laboratory for Space Technology Experimental Project), which is a pico-class satellite for verification of core space technologies. In this study, we have verified structural safety and functionality of the developed payloads under a qualification temperature range through the QM thermal vacuum test. Additionally, a reliability of thermal model of the payloads has been confirmed by performing a thermal correlation based on the thermal balance test results.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.3
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• pp.30-36
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• 2004

As fiber reinforced composite materials are widely used in aircraft, space structures and robot arms, the study on the non-destructive testing methods of the composite materials has become an important research area for improving their reliability and safety. In this paper, the AE signal analyzer with the resonance circuit to extract the specified frequency of the acoustic emission signal were designed and fabricated. The noise levels of the fabricated AE signal analyzer by the disturbance such as impact or mechanical vibration had a very small value comparable to those of the conventional AE signal analyzer. Also, the fabricated AE signal analyzer was proved to have about the same crack detection capabilities with the conventional AE signal analyzer under the static and dynamic tensile tests of the composite materials.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.4
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• pp.139-146
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• 2008

Conductors in overhead transmission lines are exposed under various environmental conditions for a long period of time, so that they may be slowly degraded due to air pollutant or thermal history. Aged conductors may reduce power system reliability and public safety. Therefore, diagnosis of aged conductors in service becomes more important concerns with respect to keeping power delivery stable with a proper capability, replacing aged conductors, or constructing a new line. In this paper, we posed a new method to diagnose the refurbishment life and estimate the remaining life of aged conductors by measuring dips. As analyzing some relations of conductor temperature, conductor current, and tension load, it could be verified that dip exactly shows mechanical tension loss for aged conductor. Based on several simulation results, it was shown that the proposed method may be effectively used to diagnose the refurbishment life or remaining one of overhead conductors.