• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.2
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• pp.131-138
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• 2011

The previous FPGA cluster systems for a brute force search of DES keyspace have showed cost efficient performance, but the research on optimized implementation of the DES algorithm on a single FPGA has been insufficient. In this paper, the optimized DES implementation for a single FPGA of the commercial FPGA cluster system with 77 Xilinx Virtex5-LX50 FPGAs is proposed. Design space exploration using the number of pipeline stages in a DES core, the number of DES cores and the maximum clock frequency of a DES core is performed which leads to integrating 16 DES cores running at 333MHz. Also low power design is applied to reduce the loss of performance caused by limitation of power supply on each FPGA which results in fitting 8 DES cores running at 333MHz. When the proposed DES implementations would be used in the FPGA cluster system, it is estimated that the DES key would be found at most 2.03 days and 4.06 days respectively.

• International Journal of Computer Science & Network Security
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• v.24 no.4
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• pp.60-66
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• 2024

Host's data during transmission. Data tempering results in loss of host's sensitive information, which includes number of VM, storage availability, and other information. In the distributed cloud environment, each server (computing server (CS)) configured with Local Resource Monitors (LRMs) which runs independently and performs Virtual Machine (VM) migrations to nearby servers. Approaches like predictive VM migration [21] [22] by each server considering nearby server's CPU usage, roatative decision making capacity [21] among the servers in distributed cloud environment has been proposed. This approaches usage underlying server's computing power for predicting own server's future resource utilization and nearby server's resource usage computation. It results in running VM and its running application to remain in waiting state for computing power. In order to reduce this, a decentralized decision making hybrid model for VM migration need to be proposed where servers in decentralized cloud receives, future resource usage by analytical computing system and takes decision for migrating VM to its neighbor servers. Host's in the decentralized cloud shares, their detail with peer servers after fixed interval, this results in chance to tempering messages that would be exchanged in between HC and CH. At the same time, it reduces chance of over utilization of peer servers, caused due to compromised host. This paper discusses, an roatative decisive (RD) approach for VM migration among peer computing servers (CS) in decentralized cloud environment, preserving confidentiality and integrity of the host's data. Experimental result shows that, the proposed predictive VM migration approach reduces extra VM migration caused due over utilization of identified servers and reduces number of active servers in greater extent, and ensures confidentiality and integrity of peer host's data.

• Journal of Climate Change Research
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• v.3 no.2
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• pp.153-159
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• 2012

CFC-12 used in mobile air conditioning(MAC) system has been replaced by R-134a, a type of HFC refrigerant, from 1991 to 1994. R-134a has since been widely used as a refrigerant of a mobile air conditioner. However, it is one of the six main green house gases listed in Kyoto Protocol, which makes it imperative to regulate its emission and develop alternative refrigerants. In this study, the concentration of leaked R-134a was measured using VT(Variable Temperature) shed and Running loss test shed to analyze the level of air conditioner refrigerant leaked in a vehicle. According to the analysis of the concentration of R-134a leaked from a vehicle parked, annual leakage amount of R-134a was in the range of 6.46~13.28 g/yr. The figure was similar with the leakage from the mobile air conditioning system currently used. In a study using the same vehicle model, a vehicle equipped with dual evaporation system had a higher leakage rate of refrigerant than a vehicle with a single evaporation system. It appears that the added fittings and joints of the dual evaporator system led to higher leakage rate. Besides, the analysis of the change in R-134a concentration under various car speed found that more refrigerant leaked under high speed(100km/hr) and but the volume of the wind did not affect to the variation of refrigerant leakage.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3D
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• pp.247-254
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• 2010

The positive effects of the air quality improvement policy have revealed sufficiently such as 3.3 trillion won of social benefits under the Environmental Zone in five years(K. Choi, 2009). In case of low-income freight truck owner, however, could be burdened with the requirement likes emission decreasing equipment. Eventually, restraint of running in the Environmental Zone would be affected their livelihood seriously. After estimating the scale of low-income freight truck owner for three alternatives with Road Freight Transport Center data, this study calculates decreased VKT to estimate the scale of monetary loss. In the result, decreased income amount of low-income freight truck owner under the restricted running estimated 6.1 trillion won during 5 years, quite exceeding 3.3 trillion won of the positive benefits as improving air quality, which means the necessity of immediate countermeasure. In other words, even though the governmental policy aimed benefits for the majority, the result implies that the total monetary losses of the minority could be exceed against the positives, therefore analysis should be considered carefully before the policy becomes effective.

• Culinary science and hospitality research
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• v.20 no.6
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• pp.211-222
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• 2014

This study was performed to identify the quality characteristic of Platycodon grandiflorum for blanching(1, 2, 3 min), drying(5, 10, 15 min) conditions and thawing methods($4^{\circ}C$, $25^{\circ}C$, running water). The color, moisture contents, pH, hardness, viable cell count of blanched Platycodon grandiflorum were lower than those of native Platycodon grandiflorum. The sensory properties of blanched Platycodon grandiflorum for blanching and drying time showed the most highly evaluated in terms of texture. The optimum blanching and drying times selected for producing of frozen Platycodon grandiflorum were 1 min, 5 min. At this condition, the blanched Platycodon grandiflorum was frozen at $-40^{\circ}C$. After thawing of frozen Platycodon grandiflorum, the thawing time was the shortest in the case of thawing in running water, and drip loss was the lowest. The color, hardness and sensory properties did not significantly differ with different thawing methods. These results show that thawing in running water is the most suitable for frozen Platycodon grandiflorum.

• Fire Science and Engineering
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• v.27 no.2
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• pp.18-24
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• 2013

Goverment and enterprises have been devoting a lot of dffort in order to prevent the loss of human and property due to a large, diversified fire, explosion, global warming and disasters caused by natural phenomena. But Enterprises came forward and running in the economy priority policy for profit-seeking until now in order to meet the macro purpose of quality improvement of national life and welfare promotion in company with National growth, as a result of lax risk management have had to endure the loss of precious lives and property. According to the '2007 Survey of public safety for the activation of the safety culture' of National Emergency Management Agency [NEMA], a insensitivity of safety in our society was surveyed 'a serious level'. In this study, surveyed need of 'step-by-step fire protection safety management system builds' in order to prevent fire safety accident and improvement of safety awareness level through a systematic management and real condition estimation of not only large business that can control risk management, but also small business that has a big risk to occur accident easily according to small budget and organization.

• Bulletin of the Korean Space Science Society
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• 2008.10a
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• pp.37.2-37.2
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• 2008

Korea-Japan Joint VLBI Correlator (KJJVC), to be used for Korean VLBI Network (KVN) in Korea Astronomy & Space Science Institute (KASI), is a high-speed calculator that outputs the correlation results in the maximum speed of 1.4GB/sec.To receive and record this data keeping up with this speed and with no loss, the design of the software running on the data archive system for receving and recording the output data from the correlator is very important. But, the simple kind of programming using just single thread that receives data from network and records it by turns, can cause a bottleneck effect while processing high speed data and a probable data loss, and cannot utilize the merit of hardwares supporting multi core or hyper threading, or operating systems supporting these hardwares. In this talk we summarize the design of the data transfer software for KJJVC and high speed, large capacity data archive system using general socket programming and multi threading techniques, and the pre-BMT(Bench Marking Test) results from the tests of the storage product providers' proposals using this software.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.16 no.1
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• pp.11-21
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• 2020

This study aims to develop and advance the evaluation technology for assessing PHWR safety. For this purpose, the complete loss of AC power or station blackout (SBO) was selected as a target accident scenario and the analysis model to evaluate the plant responses was envisioned into the MARS-KS input model. The model includes the main features of the primary heat transport system with a simplified model for the horizontal fuel channels, the secondary heat transport system including the shell side of steam generators, feedwater and main steam line, and moderator system. A steady state condition was achieved successfully by running the present model to check out the stable convergence of the key parameters. Subsequently, through the SBO transient analyses two cases with and without the coolant leakage via the PHTS pumps were simulated and the behaviors of the major parameters were compared. The sensitivity analysis on the amount of the coolant leakage by varying its flow area was also performed to investigate the effect on the system responses. It is expected that the results of the present study will contribute to upgrading the evaluation technology of the detailed thermal hydraulic analysis on the SBO transient of the operating PHWRs.

• Journal of the Society of Naval Architects of Korea
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• v.50 no.3
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• pp.145-152
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• 2013

Recently, with oil price jumping and environmental issues, Green ship is paid deep attention to by ship owner, operator, builder, class and government. Fuel efficiency and reduction of $CO_2$ emissions are expected to have a strong influence on the design and operation of merchant ships. Many ship owners and operators are seeking the more economic method by the best operating route and the application of reliable and effective energy saving devices. With the Energy Efficiency Design Index (EEDI) in 2013 attention will more than ever be focused at achieving maximum fuel economy in the hydrodynamic design of hull forms, their appendages and propellers. IMO requirements for $CO_2$ emission for ships will now be implemented for vessels ordered from 1st January 2013. So far, a lot of new idea and patents have been proposed, tested, claimed and applied for various kinds of ship type. This paper shows numerical and experimental work related to a study on a energy saving devices particularly for fuller ship such as merchant vessel of Tanker and Bulker. From the bare hull wake measurements, typical upper/lower asymmetry of hull wake at the propeller disk was found. The pre-swirl duct have been designed and reviewed to recover the loss of propeller running in that condition. The general function of the pre-swirl duct was set to work against this asymmetry of wake and generate pre-swirled flow into the propeller against the propeller rotating direction.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.119-124
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• 2017

In 1997, IBM's DeepBlue won the world chess championship, Garry Kasparov, and recently, Google's AlphaGo won all three games against Ke Jie, who was ranked 1st among all human Baduk players worldwide, interest in deep running has increased rapidly. DeepPurple, proposed in this paper, is a AI chess engine based on deep learning. DeepPurple Chess Engine consists largely of Monte Carlo Tree Search and policy network and value network, which are implemented by convolution neural networks. Through the policy network, the next move is predicted and the given situation is calculated through the value network. To select the most beneficial next move Monte Carlo Tree Search is used. The results show that the accuracy and the loss function cost of the policy network is 43% and 1.9. In the case of the value network, the accuracy is 50% and the loss function cost is 1, respectively.