• The Transactions of the Korean Institute of Electrical Engineers
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• v.38 no.7
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• pp.524-538
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• 1989

A new bilateral series resonant inverter and its control method are proposed. The proposed inverter consists of zero current switched cycloconverter. Output voltage is regulated by modulating the average magnitude of resonant current sinusoidally. Cycloconverter synthesizes low frequency output voltage from high frequency resonant current pulses. In the proposed inverter, bidirectional power flow in possible and isolation transformer is miniaturized. The proposed control method is verified through simulation and experiment. The proposed inverter will satisfy the small size and low cost requirements of small Uninterruptible Power Supply (UPS) of less than 1 KVA suitable for micro-computers and electronic equipments used in office and home automation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.557-560
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• 2014

In digital communications systems, an interleaver spreads burst errors occurred in channels and makes it random errors. As a result, the signals are rearranged and encrypted to the 3rd party. Deinterleaving this unknown interleaved signal is very important in electronic warfare and various researches on reconstruction of interleaved signal have been studied in the literature. Unlike previous researches which is mainly about helical scan interleaver or bit unit interleaver, in this paper, we estimate the symbol unit convolutional interleavr and shortened Reed-Solomon code parameters such as the number of stages of interleaver, a codeword length and a data symbol length and propose an specific algorithm to obtain the parameters from the unknown interleaved signal and simulate this algorithm as well.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.3
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• pp.90-98
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• 2011

The recognition and classification of paddy rice disease are of major importance to the technical and economical aspect of agricultural industry over the world. Computer vision techniques are used to diagnose rice diseases and to efficiently manage crops. Segmentation of lesions is the most important technique to detect paddy rice disease early and accurately. A new Gaussian Mean (GM) method was proposed to segment paddy rice diseases in various color spaces. Different color spaces produced different results in segmenting paddy diseases. Thus, this empirical study was conducted with the motivation to determine which color space is best for segmentation of rice disease. It included five color spaces; NTSC, CIE, YCbCr, HSV and the normalized RGB(NRGB). The results showed that YCbCr was the best color space for optimal segmentation of the disease lesions with 98.0% of accuracy. Furthermore, the proposed method demonstrated that diseases lesions of paddy rice can be segmented automatically and robustly.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.43 no.4 s.310
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• pp.23-30
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• 2006

This paper presents design andd verification of a circuit that improves the control-operation problems of Stored Program Optical Computer (SPOC), which is an optical computer using $LiNbO_3$ optical switching element. Since the memory of SPOC takes the Delay Line Memory (DLM) architecture and instructions that are needless of operands should go though memory access stages, SPOC memory have problems; it takes immoderate access time and unnecessary operations are executed in Arithmetic Logical Unit (ALU) because desired operations can't be selectively executed. In this paper, improvement on circuit has been achieved by removing the memory access of instructions that are needless of operands by decoding instructions before locating operand. Unnecessary operations have been reduced by sending operands to some specific operational units, not to all the operational units in ALD. We show that total execution time of a program is minimized by using the Dual Instruction Register(DIR) architecture.

• Journal of Korea Society of Industrial Information Systems
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• v.8 no.2
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• pp.7-13
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• 2003

The Internet presents a unique platform for disseminating digital content such as music, video, games, software, text, business and proprietary corporate information. It promises ubiquitous access, while at the same time fundamentally challenging the traditional rules of ownership and distribution of content. In such environment, safe protection and proper delivery of digital content would be a crucial requirement toward a new e-business model. Research on the Digital Rights Management (DRM) focuses on filling this functional vacancy of the market transition by providing a more viable business model based. XrML(eXtensible Rights Markup Language) provides a universal tool for specification of rights, fees, and issuing conditions(licenses) associated with the use and protection of digital content. ContentGuard has developed XrML to unify the Digital Rights Management(DRM) specifications and encourage interoperability. It seems that all working groups of DRM agree to use XrMl for their right description language.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.2
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• pp.114-123
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• 2009

Context-aware systems are reactive computing systems, aware of external context. Considering various sensors and actuators connected, application programming on top of such systems is known to be much more complex than in contentional ones. This paper suggests a formal framework for context-aware systems, by extracting their common properties. That makes a useful birds-eye view for the behaviors of a whole complex system, as a base for a convenient developing environment and systematic analysis. In this framework, reactive-ness is handled by event-condition-action rules and global state-transitions, which are essential in a lot of context-aware applications. In addition, behaviors of each elementary device are modelled with its own state-transitions, and tightly bound to the entire task.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.5
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• pp.95-102
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• 2008

This paper presents an appropriate approach for modeling noise in Computed Radiography(CR) images of high strength materials. The approach is specifically designed for types of noise with the statistical and nonlinear properties. CR images Ere degraded even before they are encoded by computer process. Various types of noise often contribute to contaminate radiography image, although they are detected on digitalization. Quantum noise, which is Poisson distributed, is a shot noise, but the photon distribution on Image Plate(IP) of CR system is not always Poisson process. The statistical properties are relative and case-dependant due to its material characteristics. The usual assumption of a distribution of Poisson, binomial and Gaussian statistics are considered. Nonlinear effect is also represented in the process of statistical noise model. It leads to estimate the noise variance in regions from high to low intensity, specifying analytical model. The analysis approach is tested on a database of steel tube step-wedge CR images. The results are available for the comparative parameter studies which measure noise coherence, distribution, signal/noise ratios(SNR) and nonlinear interpolation.

• The Journal of Society for e-Business Studies
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• v.19 no.4
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• pp.45-60
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• 2014

Dentist can obtain 3D anatomical information without distortion and information loss by using dental Computed Tomography scan images on line, and also can make the preoperative plan of implant placement or orthodontics. It is essential to segment individual tooth for making an accurate diagnosis. However, it is very difficult to distinguish the difference in the brightness between the dental and adjacent area. Especially, the root of a tooth is very elusive to automatically identify in dental CT images because jawbone normally adjoins the tooth. In the paper, we propose a method of automatically tooth region segmentation, which can identify the root of a tooth clearly. This algorithm separate the tooth from dental CT scan images by using Seeded Region Growing method on dental crown and by using Level-set method on dental root respectively. By using the proposed method, the results can be acquired average 19.2% better accuracy, compared to the result of the previous methods.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.2
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• pp.397-404
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• 2019

This study developed the ICT curriculum focusing on apartment security guards and analyzed the actual application results. We developed the educational contents and it designed ICT job courseware for elder education by considering and that designed in consideration of the computer attitudes and physical and cognitive characteristics of the elderly. The educational program was applied to the experimental group and the satisfaction and the educational effect were analyzed through the pre and post test results. As a result of the analysis, the satisfaction level of the education program was higher than the average of 4.00 points. The elderly informal education program was examined by using the qualitative assessment test tool before and after the application of the education program. Internet self-efficacy of experiment group, improvement of internet utilization ability, usage of internet use, personal information willingness, life correction, elimination of conflict among generations, self-confidence, and internet stress increased statistically significantly. These results suggest that the "Private Expense ICT Job Training" program developed in this study can be effective for elderly informatization and can be applied to other elderly education programs and contribute to promotion.

• Convergence Security Journal
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• v.18 no.2
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• pp.133-139
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• 2018

The 5 Game changer means the concepts of the army's operation against the enemy's asymmetric threats so that minimize damage to the public and leads to victory in war in the shortest time. A study of network architecture of Dronebot operation is a key study to carry out integrated operation with integrated C4I system by organically linking several drones battle groups through ICT. The NBC reconnaissance drones can be used instead of vehicles and humans to detect NBC materials and share situations quickly. However, there is still a lack of research on the swarm flight of the NBC reconnaissance drones and the weaknesses of cyber electronic warfare. In this study, we present weaknesses and countermeasures of CBRNs in swarm flight operations and provide a basis for future research.