• Journal of the Korea Society for Simulation
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• v.16 no.3
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• pp.11-18
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• 2007

Recently, as weapon systems have been more diverse and complicated, the factors of risk increase in development. Consequently, demanding reduction of acquired costs and period increase. Under the acquisition environment, more efficiently to develop weapon system, the necessity of application of defense M&S from requirement phase is on the rise. As the importance of M&S is stressed under distributed environment, so the standard of M&S(HLA, SEDRIS, etc.) and the system engineering process, namely FEDEP(Federation Development & Execution Process) have been developed. In this paper using the 5 phase expression, we constructed underwater engagement simulation(UNES) that prototype to develop naval weapon system test bed which take up integrated architecture in HLA. we developed simulators according to FEDEP for expandability and described process applying FEDEP fur UNES development.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.2
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• pp.325-330
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• 2017

Face recognition technology has been studied for decades and is being used in various areas such as security, entertainment, and mobile services. The main problem with face recognition technology is that the recognition rate is significantly reduced depending on the environmental factors such as brightness, illumination angle, and image rotation. Therefore, in this paper, we propose a robust face recognition against lighting variation using CNN which has been recently re-evaluated with the development of computer hardware and algorithms capable of processing a large amount of computation. For performance verification, PCA, LBP, and DCT algorithms were compared with the conventional face recognition algorithms. The recognition was improved by 9.82%, 11.6%, and 4.54%, respectively. Also, the recognition improvement of 5.24% was recorded in the comparison of the face recognition research result using the existing neural network, and the final recognition rate was 99.25%.

• Journal of the Korean Geotechnical Society
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• v.29 no.7
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• pp.5-15
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• 2013

Clogging phenomenon is one of the important problems in deteriorated tunnels, and it caused inhibition of drainage system by long-term behavior. Clogging phenomenon is mainly composed of $CaCO_3$ in the form calcite. Calcite is generally created by the reaction of $Ca(OH)_2$ with $CO_2$ emitted from vehicles. The structure of deteriorated tunnels was simulated and the setting of outflow from drainage pipe was observed in this study. The test was experienced by changing the slope of drainage system because existing drainage system was pracitced almost below $5^{\circ}$. As a result, in case of drainage system's slope is $2^{\circ}$, Quantum Stick has an effect for prohibiting scale in drainage system, but magnetic treatment was not effective. As a result, in case of drainage system's slope is $5^{\circ}$, both technologies were effective for prohibiting scale in drainage system, but Quantum Stick was especially more effective than magnetic treatment.

• The Transactions of the Korea Information Processing Society
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• v.2 no.5
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• pp.777-786
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• 1995

This paper describes several algorithms for technology mapping of logic functions into interesting and popular FPGAs that use look-up table memories. In order to improve the technology mapping for FPGA, some existing multi-level logic synthesis, decomposition reduction and packing techniques are analyzed and compared. And then new algorithms such as node-pair decomposition, merging fanin, unified reduction and multiple output decomposition which are used for combinational logic design, are proposed. The cost function is used to minimize the number of CLBs and edges of the network. The cost is a linear combination of each weight that is given by user. Finally we compare our new algorithm with previous logic design technique［8］. In an experimental comparison our algorithm requires 10% fewer CLB and nets than SIS-pga.

• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.803-806
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• 2020

The body shape measurement method using 3D images has been widely used due to the recent development of 3D measurement cameras and algorithms. Existing 3D imaging devices are expensive devices, and there is a limit to their universalization. Due to the recent spread of inexpensive 3D cameras and the development of various measurement methods, various possibilities are being shown. It is expected to have a great impact on the medical device market that requires accurate data collection. Various medical device products using artificial intelligence are emerging, and accurate data collection is the most important to develop accurate artificial intelligence algorithms. Collection equipment using 3D cameras is expected to act as a major factor in the development of artificial intelligence algorithms using 3D images.

• Journal of Digital Contents Society
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• v.4 no.2
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• pp.127-137
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• 2003

A Web crawler is an important Internet software technology used in a variety of Internet application software which includes search engines. As Internet continues to grow, implementations of high performance web crawlers are urgently demanded. In this paper, we study how to support dynamic scheduling for a multiprocess-based web crawler. For high performance, web crawlers are usually based on multiprocess in their implementations. In these systems, crawl scheduling which manages the allocation of web pages to each process for loading is one of the important issues. In this paper, we identify issues which are important and challenging in the crawl scheduling. To address the issue, we propose a dynamic crawl scheduling framework and subsequently a system architecture for a web crawler with dynamic crawl scheduling support. This paper presents the design of the Web crawler with dynamic scheduling support.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.8
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• pp.37-44
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• 2004

This paper describes a new GaAs-based surface-micromachined microstrip line supported by dielectric post and air-gapped signal line with ground metal. This new type of dielectric-supported air-gapped microstripline(DAML) structure is developed using surface micromachining techniques to provide easy means of airbridge connection between the signal lines and to archive low losses at millimeter-wave frequency band with wide impedance range. Each DAMLs with the length of 5 mm are fabricated and the measured characteristics are compared with those of the conventional microstrip transmission line. These transmission lines are composed of 10 ${\mu}{\textrm}{m}$ height of signal line, post size of 10 ${\mu}{\textrm}{m}$ ${\times}$ 10 ${\mu}{\textrm}{m}$ and post height of 9 ${\mu}{\textrm}{m}$. By elevating the signal lines from the substrate using the micromachining technology, the substrate dielectric loss can be reduced Compared with of the conventional microstrip transmission line showing 7.5 dB/cm loss at 50 GHz, the loss can be reduced to 1.1 dB/cm loss at 50 GHz.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.1A
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• pp.27-33
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• 2009

This paper proposes transmit power control techniques with fading channel prediction scheme based on recurrent neural network for high-speed mobile communication systems. The operation result of recurrent neural network which is derived interpretively solves complexity problems of neural network circuit, and channel gain of multiple transmit antenna is derived with maximum ratio combining(MRC) by using the operation result, and this channel gain control transmit power of each antenna. simulation results show that proposed method has a outstanding performance compared to method that is not to be controlled power based on channel prediction. Most of legacy studies are for robust receive technique of fading signals or channel prediction of fading signals limited low-speed mobility, but in open loop Power control, proposed channel prediction method decrease system complexity with removal of fading effect in transmitter.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10A
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• pp.752-759
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• 2009

Cooperative diversity is an effective technique to combat multi-path fading. When this technique is applied to energy-constrained wireless sensor networks, it is a key issue to design appropriate relay selection and power allocation strategies. In this paper, we proposed a new multi-relay selection and power allocation algorithm to maximize network lifetime. The algorithm are composed of two relay selection stages, where the channel condition and residual power of each node were considered in multi-relay selection and the power is fairly allocated proportional to the residual power, satisfies the required SNR at destination and minimizes the total transmit power. In this paper, proposed algorithm is based on AF (amplify and forward) model. We evaluated the proposed algorithm by using extensive simulation and simulation results show that proposed algorithm obtains much longer network lifetime than the conventional algorithm.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.3
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• pp.405-415
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• 2020

With the increase in smartphone user, mobile forensics has become an essential element in modern digital forensic investigation. Mobile messenger data is very important data in mobile forensics because it can acquire information such as user's life pattern and mental state. In order to analyze messenger data, a decryption technique of an encrypted messenger data is required. Since most messengers provide a message deleting function, a technique for recovering deleted messages is required. WeChat Messenger, a messenger used by about 1 billion people around the world, uses IMEI (International Mobile Equipment Identity) information to encrypt data and provides message deletion function. In this paper, we propose a data decryption method in the absence of IMEI information and propose a method for recovering deleted messages using FTS (Full Text Search) database created for full-text search function of SQLite database.