• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.5
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• pp.1153-1165
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• 2019

Recently, threats of hacking have been increasing on the national intelligence service network and key infrastructure, including the defense field. The defense information system responds to threats from the outside through the network separation, but if the defense information system is hacked, it has a serious impact on the operations of wartime or peacetime military forces. Today, cyberattacks and threats are rising to unpredictable levels and making it practically impossible to completely block and prevent hacking threats completly. So, in this study proposed a maturity model to assess the level of cyber-resilience, which is the ability to ensure the system's viability and maintain continuity through rapid response and recovery if signs of cyberattacks by the defense information system are expected or occurred. The proposed maturity model is expected to contribute to improving the cyber security level of the defense information system by assessing the level of cyber resilience of the defense information system and identifying and supplementing fields that are lacking.

• The Journal of the Korea Contents Association
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• v.20 no.12
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• pp.136-144
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• 2020

Previous studies report that labor investment inefficiency occurs as the information asymmetry becomes severe and the agency problem between managers and external investors increases. Therefore, it is highly likely that managers will make opportunistic decisions that can damage corporate value in companies with high labor investment inefficiency. This study examines whether the value relevance of accounting information decreases as labor investment inefficiency increases as it is less likely that investors in the market use the accounting information of companies in which labor investment decisions are made inefficiently. Labor investment efficiency is measured as the difference between the actual level of labor investment and the expected level of optimal labor investment. Larger difference between the actual level of labor investment and the expected level of optimal labor investment is considered as higher inefficiency in labor investment. Using data of firms listed on the Korea Stock Exchange from 2002 to 2018, empirical results show that the value relevance of earnings decreases as the inefficiency of labor investment increases. This research provides empirical evidence on whether investment inefficiency in labor, which is an important factor in the competitiveness of a company, reduces the information usefulness of reported earnings.

• Journal of Radiation Industry
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• v.17 no.4
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• pp.509-518
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• 2023

The Kori Unit 1 nuclear power plant, which is planned to be dismantled after permanent shutdown, is expected to generate a large amount of various types of radioactive waste during the dismantling process. For the disposal of Very-low-level waste, which is expected to account for the largest amount of generation, the Korea Radioactive waste Agency (KORAD) is in the process of detailed design to build a 3-phase landfill disposal facility in Gyeongju. In addition, a large container is being developed to efficiently dispose of metal and concrete waste, which are mainly generated as Very low-level waste of decommissioning. In this study, based on the design characteristics of the 3-phase landfill disposal facility and the large container under development, radiation exposure dose evaluation was performed considering the normal and accident scenarios of radiation workers during operation. The direct exposure dose evaluation of workers during normal operation was performed using the MCNP computer program, and the internal and external exposure dose evaluation due to damage to the decommissioning waste package during a drop accident was performed based on the evaluation method of ICRP. For the assumed scenario, the exposure dose of worker was calculated to determine whether the exposure dose standards in the domestic nuclear safety act were satisfied. As a result of the evaluation, it was confirmed that the result was quite low, and the result that satisfied the standard limit was confirmed, and the radiational disposal suitability for the 3-phase landfill disposal facility of the large container for dismantled radioactive waste, which is currently under development, was confirmed.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.703-706
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• 1998

This paper presents an efficient substrate-bias generator(SBG)for low-power, high-density DRAM's The proposed SBG can supply stable voltage with switching the supply voltage of driving circuit, and it can substitude the small capacitance for the large capacitance. The charge pumping circuit of the SBG suffere no VT loss and is to be applicable to low-voltage DRAM's. Also it can reduce the power consumption to make VBB because of it's high pumping efficiency. Using biasing voltage with positive temperature coefficient, VBB level detecting circuit can detect constant value of VBB against temperature variation. VBB level during VBB maintaining period varies 0.19% and the power dissipation during this period is 0.16mw. Charge pumping circuit can make VBB level up to -1.47V using VCC-1.5V, and do charge pumping operation one and half faster than the conventional ones. The temperature dependency of the VBB level detecting circuit is 0.34%. Therefore the proposed SBG is expected to supply a stable VBB with less power consumption when it is used in low power DRAM's.

• Journal of Digital Convergence
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• v.7 no.2
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• pp.35-41
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• 2009

The information technology, in the digital economy era, does a very important role not only for the country's administrative management innovation but also for the business and for the everyday life. Specifically, the e-business for the company or organization is defined as "using the Internet and IT, rescheduling of business process management activities to increase productivity and efficiency and to create new business opportunities." Thanks to the Korea's recent efforts, overall level of informatization and digitalization is able to receive high praise. But the e-business readiness (e-readiness) level is still expected a lot of room for improvement. In this paper, I try to analyze the informatization level of Korea's by the EIU's e-business readiness index and IT industry competitiveness index, to prepare a full-scale e-business era of global competitiveness through any preparation that could do to improve the situation from the analysis of statistical data.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.25 no.4
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• pp.124-129
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• 2017

Clouds are an important factor in aircraft flight. In particular, a significant impact on small aircraft flying at low altitude. Therefore, we have verified and characterized the low level cloud prediction data of the Unified Model(UM) - based Local Data Assimilation and Prediction System(LDAPS) operated by KMA in order to develop cloud forecasting service and contents important for safety of low-altitude aircraft flight. As a result of the low level cloud test for seven airports in Korea, a high correlation coefficient of 0.4 ~ 0.7 was obtained for 0-36 leading time. Also, we found that the prediction performance does not decrease as the lead time increases. Based on the results of this study, it is expected that model-based forecasting data for low-altitude aviation meteorology services can be produced.

• Journal of Oriental Neuropsychiatry
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• v.10 no.2
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• pp.85-103
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• 1999

In order to prove the anticonvulsive effect of the fragrance of Magnoliae Flos in convulsion-induced mice, experiments were performed on anticonvulsive effect, GABA level, glutamic acid level, GABA-T activity and GAD activity. The results were obtained as follows: 1. As far as anticonvulsive effect was concerned, on the convulsion induced by such as maximal electric seizure, strychnine, bicuculline, or picrotoxin it was not significant, but the convulsion induced by pentylenetetrazole it was significant comparing to the control group. 2. GABA level was increased significantly in mice. 3. Glutamic acid level was decreased significantly in mice. 4. GABA-T activity was decreased by the fragrance of Magnoliae Flos. 5. The fragrance of Magnoliae Flos was not effective in GAD activity. From above result, the fragrance of Magnoliae Flos had significant effects on convulsion induced by pentylenetetrazole, so it is expected to clinical application on convulsive diseases such as epilepsy.

• International Journal of Concrete Structures and Materials
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• v.7 no.3
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• pp.175-182
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• 2013

A damage-based approach for the performance-based seismic assessment of reinforced concrete frame structures is proposed. A new methodology for structural damage assessment is developed that utilizes response information at the material level in each section fiber. The concept of the damage evolution is analyzed at the section level and the computed damage is calibrated with observed experimental data. The material level damage parameter is combined at the element, story and structural level through the use of weighting factors. The damage model is used to compare the performance of two typical 12-story frames that have been designed for different seismic requirements. A series of nonlinear time history analyses is carried out to extract demand measures which are then expressed as damage indices using the proposed model. A probabilistic approach is finally used to quantify the expected seismic performance of the building.

• Journal of Mechanical Science and Technology
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• v.14 no.6
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• pp.645-654
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• 2000

In this paper, low level control algorithms of a metal belt CVT are suggested. A feedforward PID control algorithm is adopted for line pressure based on a steady state relationship between the input duty and the line pressure. Experimental results show that feedforward PID control of the line pressure guarantees a fast response while reducing the pressure undershoot which may result in belt slip. For ratio control, a fuzzy logic is suggested by considering the CVT shift dynamics and on-off characteristics of the ratio control valve. It is found from experimental results that a desired speed ratio can be achieved at steady state in spite of the fluctuating primary pressure. It is expected that the low level control algorithms for the line pressure and speed ratio suggested in this study can be implemented in a prototype CVT.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.561-562
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• 2008

In this paper, we propose a establishment of system level environment to exploit PC system with SSD (Solid State Disk) by using TLM (Transaction Level Modeling) method with SystemC language. The reason why we choose this modeling method is that it eases RTL (Register Transfer Level) modeling burdens and we can accurately estimate the performance about different architectural changes. Also, it provides simulation speed which is relatively faster than RTL modeling method. The baseline architectural platform we implemented showed that SSD's internal transfer time is a dominant factor, so we need to improve that part and it is expected to be a good simulator to measure the system's overall performance by exploiting SSD's internal architectures.