• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.132-138
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• 2012

Existing network layer firewall security support is one that does not support the higher layer, the application layer of a vulnerable web application security. Under these circumstances, the vulnerability of web applications to be able to defend a Web Application Firewall is positioned as a solver to solve the important security issues of businesses spotlighted in the next generation of security systems, and a very active market in the market other than domestic is expected to be formed. However, Firewall Web has not yet proposed a standard which can be used to test the performance of the Web Application Firewall Web Application Firewall and select the products of trust hardly Companies in BMT conduct their own individual problems and the cost of performance testing technologies, there is a limit. In this study, practically usable BMT model was developed to evaluate the firewall vendor. Product ratings ISO / IEC 9126, eight product characteristics meet the performance and characteristics of a web application firewall entries are derived. This can relieve the burden on the need to be evaluated in its performance testing of Web firewall, and can enhance the competitiveness of domestic-related sectors, by restoring confidence in the product can reduce the dependence on foreign products.

• Journal of Energy Engineering
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• v.21 no.3
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• pp.243-248
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• 2012

In this study, The report analysed the characteristics of power drop and damage of surface in solar cell through high temperature and humidity test. The solar cells were tested during the 1000hr in $85^{\circ}C$ temperature and 85% humidity conditions, that excerpted standard of PV Module(KS C IEC-61215). An analysis of the cell surface through EL(Electroluminescence), the cell has partly change of surface in yearly. Single-crystalline Solar cell efficiency is decreased from 17.7% to 15.6% and decreasing rate is 11.9%. On the other hand, Poly-crystalline Solar cell efficiency is decreased from 15.5% to 14.0% and decreasing rate is 9.3%. A comparison of the fill factor for analysis of electro characteristic in yearly, Single-crystalline Solar cell efficiency is decreased from 78.7% to 78.1% and decreasing rate is 4.7%. On the other hand, Poly-crystalline Solar cell efficiency is decreased from 78.1% to 76.7% and decreasing rate is 1.8%. Single-crystalline has more bigger power drop than poly-crystalline by the silicon purity and silicon atom arrangement. Also, FF decreasing rate has more bigger drop than efficiency decreasing rate for the reason that the damage of surface by exterior environmental factor is the more influence in cell than other reason that is decreasing FF by damage of p-n junction.

• Journal of Energy Engineering
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• v.21 no.3
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• pp.249-253
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• 2012

In this study, The report analysed the characteristics of power drop in solar cell through thermal shock test. The solar cells were tested 500 cycles in $-40^{\circ}C$ lowest temperature and $120^{\circ}C$ highest temperature by thermal shock test on ironbound conditions, that excerpted standard of PV Module(KS C IEC-61215). The result of the efficiency analysis through measure of I-V, efficiency of Cell decreased from 13.9% to 11.0% and decreasing rate was 20.9% after test. The result of the surface analysis through EL, solar cell has damage of gridfinger and ribbon joint. Cell cracks were founded in damage of cells through cross section of solar cells. Also, Fill factors were decreased from 72.3% to 62.0% after thermal shock test and decreasing rate is 11.8%. therefore, Yearly power drop is aggravated with facts that cell crack, damage of surface and power loss of cell by change of I-V characteristic curve with decreasing of parallel resistance.

• Journal of Broadcast Engineering
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• v.18 no.6
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• pp.835-849
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• 2013

Joint Collaborative Team on Video Coding (JCT-VC), which have founded ISO/IEC MPEG and ITU-T VCEG, has standardized High Efficiency Video Coding (HEVC). Standardization of HEVC has started with purpose of twice or more coding performance compared to H.264/AVC. However, flexible and hierarchical coding block and recursive coding structure are problems to overcome of HEVC standard. Many fast encoding algorithms for reducing computational complexity of HEVC encoder have been proposed. However, it is hard to implement a real-time HEVC encoder only with those fast encoding algorithms. In this paper, for implementation of software-based real-time HEVC encoder, data-level parallelism using SIMD instructions and CPU/GPU multi-threading methods are proposed. And we also proposed appropriate operations and functional modules to apply the proposed methods on HM 10.0 software. Evaluation of the proposed methods implemented on HM 10.0 software showed 20-30fps for $832{\times}480$ sequences and 5-10fps for $1920{\times}1080$ sequences, respectively.

• Fire Science and Engineering
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• v.25 no.6
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• pp.136-145
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• 2011

One of a large proportion among the causes of fire is electrical factors, and of fire by electric factors, the accident which accounted for over certain percentage is electric leakage and ground fault. In order to reduce the electric leakage and ground fault, the technical guidelines on the protection of ground fault in the low-voltage electrical line (KECG 1091-2011) was amended for reflecting recent international standard, IEC 60364-4-41, and new conservation methods, which improved the reliability by recovering the facility's all-time use operation and breakdown defect, was on the rise. Accordingly, in this paper, after grasping the fire's status for last 10 years and analyzing the risk of electrical fires, and as a way to improve the electric leakage and ground fault accident which accounted for more than certain percentage, the revision of KECG 1091-2011 will be reviewed. And then, after applying to the preventive conservation methods in order to enhance the protection reliability of electric leakage and ground fault detection, the problems at issue routine inspection scheme and durable years scheme in time-scheduled conservation method are listed, along with suggestion of the problem-solving scheme, and the leakage current integrated monitoring systems and digital electric leakage devices by status monitor conservation method will be proposed.

• KIPS Transactions on Software and Data Engineering
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• v.4 no.12
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• pp.549-560
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• 2015

There is a wide variety of data quality attributes such as the ones proposed by the ISO/IEC organization and also by many other domestic and international institutions. However, it takes considerable time and costs to apply those criteria and guidelines to real environment. Therefore, it needs to define data quality evaluation attributes which are easily applicable and are not influenced by organizational environment limitations. The purpose of this paper is to derive data quality attributes and order of their priorities based on customer requirements for managing the process systematically and evaluating the data quantitatively. This study identifies the customer cognitive constructs of data quality attributes using the RGT(Repertory Grid Technique) based on a Korean quality standard model (DQC-M). Also the correlation analysis on the identified constructs is conducted, and the evaluation attributes is prioritized and ranked using the AHP. As the results of this paper, the consistent system, the accurate data, the efficient environment, the flexible management, and the continuous improvement are derived at the first level of the data quality evaluation attributes. Also, Control Compliance(13%), Regulatory Compliance(10%), Requirement Completeness(9.6%), Accuracy(8.4%), and Traceability(6.8%) are ranked on the top 5 of the 19 attributes in the second level.

• Journal of Broadcast Engineering
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• v.24 no.6
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• pp.1035-1052
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• 2019

Recently, as the demand for immersive videos increases, efficient video processing techniques for omnidirectional immersive video is actively developed by MPEG-I. While the omnidirectional video provides a larger degree of freedom for a free viewpoint, the size of the video increases significantly. Furthermore, in order to compress 6 degree-of-freedom (6 DoF) videos that support motion parallax, it is required to develop a codec to yield better coding efficiency. In this paper, we develop a 6 DoF codec using Versatile Video Coding (VVC) as the next generation video coding standard. To the authors' best knowledge, this is the first VVC-based 6 DoF video codec toward the future ISO/IEC 23090 Part 7 (Metadata for Immersive Media (Video)) MPEG-I standardization. The experiments were conducted on the seven test video sequences specified in Common Test Condition (CTC) in two operation modes of TMIV (Test Model for Immersive Media) software. It is demonstrated that the proposed codec improves coding performance around 33.8% BD-rate reduction in the MIV (Metadata for Immersive Video) mode and 30.2% BD-rate reduction in the MIV view mode as compared to the state-of-the-art TMIV reference software. We also show the performance comparisons using Immersive Video PSNR (IV-PSNR) and Mean Structural Similarity (MSSIM).

• Journal of the Korean Society of Radiology
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• v.12 no.6
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• pp.713-718
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• 2018

In many previous studies, monte carlo simulation is used to produce lead-free shielding sheet, and the possibility of radiation shielding capability and weight reduction is presented. But it is difficult to simulation for binder and micro-pores because of In fact it does not provide sufficient information necessary for the commercialization process. Therefore, in this paper, the results of radiation shielding capability corresponding to filling factor was presented by using the screen printing method to provide information on gel-paste required for the commercialization process. In this study, the geometric setup for evaluate of radiation shielding ability was designed to comply with IEC 61331-1:2014 and KS A 4025. In addition, radiation irradiation conditions were 100 kVp filtered with 2.0 mmAl total filtration was applied according to KS A 4021 standard. In this study, Pb $1270{\mu}m$, $BaSO_4$ $3035{\mu}m$, $Bi_2O_3$ $1849{\mu}m$ and $WO_3$ $2631{\mu}m$ were analyzed based on ten value layer. Additionally, the filling factor was analyzed as $BaSO_4$ 38.6%, $Bi_2O_3$ 27.1%, $WO_3$ 30.15%. However, in the case of applying low-temperature high-pressure molding in the future, it is expected that the radiation shielding capability can be sufficiently improved by reducing the porosity while increasing the filling factor.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.1
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• pp.65-75
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• 2011

Power Line Communication (PLC) is a system for carrying data on a conductor used for electric power transmission. Recently, PLC has received much attention due to connection efficiency and possibility of extension. It can be used for not only alternative communication, in which communication line is not sufficient, but also for communication between home appliances. Korea Electronic Power Cooperation (KEPCO) is constructing the system, which automatically collects values of power consumption of every household. Due to the randomness and complicated physical characteristics of PLC protocol (KS X4600-1), it has been believed that the current PLC is secure in the sense that it is hard that an attacker guesses or modifies the value of power consumption. However, we show that the randomness of the protocol is closely related to state of the communication line and thus anyone can easily guess the randomness by checking the state of the communication line. In order to analyze the security of PLC, we study the protocol in detail and show some vulnerability. In addition, we suggest that PLC needs more secure protocol on higher layers. We expect that the study of PLC help in designing more secure protocol as well.

• Journal of the Microelectronics and Packaging Society
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• v.27 no.4
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• pp.55-60
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• 2020

The PERC photovoltaic (PV) modules installed in PV power plant are still reports potential-induced degradation (PID) degradation due to high voltage potential differences. This is because Na+ ions in the cover glass of PV modules go through the encapsulant (EVA) and transferred to the surface of solar cells. As positive charges are accumulated at the ARC (SiOx/SiNx) interface where many defects are distributed, shunt-resistance (Rsh) is reduced. As a result, the leakage current is increased, and decrease in solar cell's power output. In this study, to prevent of this phenomenon, a Moth-eye nanostructure was deposited on the rear surface of an optical film using Nano-Imprint Lithography method, and a solar mini-module was constructed by inserting it between the cover glass and the EVA. To analyze the PID phenomenon, a cell-level PID acceleration test based on IEC 62804-1 standard was conducted. Also analyzed power output (Pmax), efficiency, and shunt resistance through Light I-V and Dark I-V. As a result, conventional solar cells were decreased by 6.3% from the initial efficiency of 19.76%, but the improved solar cells with the Moth-eye nanostructured optical film only decreased 0.6%, thereby preventing the PID phenomenon. As of Moth-eye nanostructured optical film, the transmittance was improved by 4%, and the solar module output was improved by 2.5%.