• Journal of the Korea Convergence Society
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• v.11 no.6
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• pp.37-42
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• 2020

In the field of public informatization maintenance business, the attacks of external illegal users such as unauthorized leakage, destruction, and alteration due to intentional or inadequate management of personal information are increasing. In order to prevent such security incidents in advance, it is necessary to develop and quantitatively manage SLA indicators. This study presents the privacy SLA indicators and suggests specific methods such as information collection method and timing of the privacy SLA indicators. In order to confirm the validity and reliability of the proposed SLA indicators, an online survey was conducted with a group of experts. As a result, it was evaluated that compliance rate of personal information destruction and compliance rate of personal information protection system would be effective when applied to new and revised SLA indicators in terms of importance and validity. In the future, using SLA indicators for personal information protection as a standard for public information maintenance will contribute to improving SW quality and securing safety.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.10
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• pp.889-895
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• 2014

Machine parts and structures of a change in the displacement and strain can be evaluated safety is one of the important factors. Typically the strain gauge has been employed to measure the displacement and strain. However, this contact-type measurement method has disadvantages that are not measured under condition of specific object shape, surface roughness and temperature. In particularly, 3 point bending and 4 point bending test not use strain gauge. So its test used cross head displacement and deflect meter. Digital Image Correlation measurement methods have many advantages. It is non contact-type measurement method to measure the object displacements and strain. In addition, it is possible to measure the Map of full field displacements and strain. In this paper, measured the 3 point bending deflection using the Digital Image Correlation methods. In order to secure the reliability, Digital Image Correlation method and universal test machine were compared.

• Structural Engineering and Mechanics
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• v.72 no.5
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• pp.631-642
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• 2019

The objective of the present study is to examine the flexural behavior of two-span post-tensioned lightweight aggregate concrete (LWAC) beams using unbonded tendons and the reliability of the design provisions of ACI 318-14 for such beams. The parameters investigated were the effective prestress and loading type, including the symmetrical top one-point, two third-point, and analogous uniform loading systems. The unbonded prestressing three-wire strands were arranged with a harped profile of variable eccentricity. The total length of the beam, measured between both strand anchorages, was 11000 mm. The test results were compared with those compiled from simply supported LWAC one-way members, wherever possible. The ultimate load capacity of the present beam specimens was evaluated by the collapse mechanism of the plasticity theorem and the nominal section moment strength calculated following the provision of the ACI 318-14. The test results showed that the two-span post-tensioned LWAC beams had lower stress increase (Δf_ps) in the unbonded tendons than the simply supported LWAC beams with a similar reinforcement index. The effect of the loading type on Δf_ps and displacement ductility was less significant for two-span beams than for the comparable simply supported beams. The design equations for Δf_ps and Δf_ps proposed by ACI 318-14 and Harajli are conservative for the present two-span post-tensioned LWAC beams, although the safety decreases for the two-span beam, compared to the ratios between experiments and predictions obtained from simply supported beams.

• Journal of Korean Neurosurgical Society
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• v.38 no.4
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• pp.265-268
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• 2005

Objective : With the increasing popularity of pedicle screw fixation devices for several indications, the safety and reliability of screw insertion in the small pedicle has become a major issue. Many studies have investigated the accuracy of screw placement after pedicle screw fixation using various method. The reported displacement rates have been very different. The purpose of the study is to investigate the proper placement of pedicle screw insertion in the lumbar spine on 26 consecutive patients. Methods : Between September and December 2003, 26 consecutive patients [16women and 10men] were analyzed after transpedicular screw fixation of the lumbar and lumbosacral spine. After pedicle screw fixation in this study, 2-mm slices of CT scan were performed in all patients to detect caudal and cranial deviation of screw and medial and lateral deviation. Pedcile screw placement related complication was evaluated clinically. Results : A total of 144 inserted pedicle were analyzed in 26patients, and 58pedicle screws [40.3%] were detected to be improper placement. There were 14level [9.0%] of caudal or cranial deviation and 44level [30.6%] of medial or lateral deviation to the pedicle. Extra-pedicle placement was found on 4levels [2.7%] with only lease of neurologic injury. Conclusion : Proper screw placement, though complication rate is low, is important not only for clinical symptom but also for biomechanics. Further study for screw placement related biomechanical changes is needed.

• The Journal of the Acoustical Society of Korea
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• v.39 no.2
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• pp.105-112
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• 2020

An analysis model of noise map is proposed to evaluate and reduce the acoustical noise of power plant and its surroundings. The sound powers of many noise sources are estimated by measuring the sound levels of major equipments in the power plant. The analysis of noise has been made by using ENPro that is a commercial program for environmental noise prediction. The proposed model is verified by comparing the results from noise analysis and measurement at several points of the power plant units 1 through 4, and residential areas. It is shown that noise map simulation using the proposed model has a reliability, since the overall noise level approximates within the error of ±2 dB. Furthermore, through noise analysis, the increasing effect of noise due to newly established units 5 and 6 on residential areas is also analyzed. Consequently, the noise barrier is designed to meet an environmental noise standard and satisfy low cost and safety conditions.

• Convergence Security Journal
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• v.19 no.4
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• pp.97-105
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• 2019

With the possibility of wireless control of the aircraft by Nicola Tesla, Unmanned Aerial Vehicle(UAV) was mainly used for military and defense purposes with the rapid development through World War I and II. As civilian applications of unmanned aerial vehicles have expanded, they have been used with various services, and attempts have been made to control various environmental changes and risk factors of unmanned aerial vehicles. However, GPS spoofing, Jamming attack and security accidents are occurring due to the communication in the unmaned aerial vehicle system or the security vulnerability of the unmanned aerial vehicle itself. In order to secure introduction of Unmanned aerial vehicle, South Korea has established Unmanned Aerial Vehicle verification system called Airworthiness Certification. However, the existing cerfication system is more focused on test flight, design and structure's safety and reliability. In this paper, we propose a unmanned aerial vehicle system model and propose security functional requirements on unmanned aerial vehicle system in the corresponding system model for secure-introduction of Unmanned Aerial Vehicle. We suggest the development direction of verification technology. From this proposal, future development directions of evaluation and verification technology of Unmanned Aerial Vehicle will be presented.

• Fire Science and Engineering
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• v.24 no.5
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• pp.150-158
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• 2010

There are lots of buildings with their deterioration in wholesale markets which have high concentration that can cause big fire due to difficulty of installing fire protection system in fire compartment, absence of safety awareness, access by many and unspecified people. There had been big fire that caused by these kind of fire weakness such as Seomun Market's in 2005 which costed tens of millions dollar, Dongmun Shopping District’s with 7 casualties. Now counter-measure against these fire is urgently needed. This study drew characteristic of current condition of wholesale markets and the one classified by main agent, fire cases and prevention of fire through statistical data. Also, current condition of fire prevention management and actual state were investigated by conducting a survey of person in charge of fire prevention and current practician. As a result, it was shown that securing professionalism of fire prevention, improvement of structural weakness of buildings, obtaining reliability on performance of fire protection system and internal fire education against practician in the market are needed.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.730-738
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• 2010

In the development of railroad station area, there are many factors about business management, but the interest of railroad users is an important factor as customer satisfaction. It is necessary to have the quality estimation of railroad service, and important factors of service as customer satisfaction aspects can be supply, reliability, convenience, and safety. In this study, primary factors are deduced in the efficiency aspects of railroad station facilities from analyzing relative importance index using AHP(Analytic Hierarchy Process) methods. The most high rank important factor is railroad station user facilities, and the AHP importance index of passenger facilities and elevator facilities for KORAIL personnel and facility users is index. The third of KORAIL personnel is movement facilities, but facility users index is sanitation. And the low important factors of KORAIL personnel and facility users are shown as the platform in passenger facilities, the rest facilities in waiting room, the escalator in going up and coming down facilities, the escalator in movement facilities, the raised letters block in guide facilities, and the parking lot in subsidiary facilities.

• Journal of Korean Tunnelling and Underground Space Association
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• v.5 no.3
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• pp.241-250
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• 2003

Rock mass is very inhomogeneous in nature and data obtained by site investigations and tests are very limited. For this reason, many uncertainties are to be included in the process of constructing structures in rock mass. In the design of a tunnel, support pattern, advance rate, and excavation method, which are important design parameters, must be determined to be optimal. However, it is not easy to determine those parameters. Moreover if those parameters are determined incorrectly, unexpected risk occurs such as decrease in the stability of a tunnel or economic loss due to the excessive supports etc. In this study, how to determine an optimal support pattern and advance rate, which are the important tunnel design parameters, is introduced based on a risk analysis. It can be confirmed quantitatively that the more supported a tunnel is, the larger reliability index becomes and the more stable the tunnel becomes. Also an optimal support pattern and advance rate can be determined quantitatively by performing a risk analysis considering construction cost and the cost of loss which can be occurred due to the collapse of a tunnel.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.8
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• pp.849-854
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• 2013

Many researches on green ship with increasing on economics, efficiency and convenience have been carried out consistently. One of them is development of diesel engines with electronic control. While small duty one for automobiles had been adopted mainly already, disseminating heavy duty one for ships has trouble due to safety and reliability. In order to solve these problem in this study, performance of electronic control and cam type engine installed in parallel on training ship HANBADA of korea maritime university was analyzed and compared. It is certain that specific fuel oil consumption of the electronic control type is lower than cam type and excellent at lower engine load, especially. And the electronic control type shows more effective characteristic at sea trial on specific fuel oil consumption.