• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.3
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• pp.427-433
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• 2002

This paper describes a design of cryptographic processor that implements the AES(Advanced Encryption Standard) block cipher algorithm "Rijndael". To achieve high throughput rate, a sub-pipeline stage is inserted into the round transformation block, resulting that the second half of current round function and the first half of next round function are being simultaneously operated. For area-efficient and low-power implementation, the round block is designed to share the hardware resources in encryption and decryption. An efficient scheme for on-the-fly key scheduling, which supports the three master-key lengths of 128-b/192-b/256-b, is devised to generate round keys in the first sub-pipeline stage of each round processing. The cryptoprocessor designed in Verilog-HDL was verified using Xilinx FPGA board and test system. The core synthesized using 0.35-${\mu}{\textrm}{m}$ CMOS cell library consists of about 25,000 gates. Simulation results show that it has a throughput of about 520-Mbits/sec with 220-MHz clock frequency at 2.5-V supply.-V supply.

• Journal of Electrical Engineering and Technology
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• v.11 no.1
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• pp.157-166
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• 2016

In this paper, a new sag and peak voltage detector is proposed for a single-phase inverter using delta square operation. The conventional sag detector is from a single-phase digital phase-locked loop (DPLL) that is based on d-q transformations using an all-pass filter (APF). The d-q transformation is typically used in the three-phase coordinate system. The APF generates a virtual q-axis voltage component with a 90° phase delay, but this virtual phase cannot reflect a sudden change in the grid voltage at the instant the voltage sag occurs. As a result, the peak value is drastically distorted, and it settles down slowly. A modified APF generates the virtual q-axis voltage component from the difference between the current and the previous values of the d-axis voltage component in the stationary reference frame. However, the modified APF cannot detect the voltage sag and peak value when the sag occurs around the zero crossing points such as 0° and 180°, because the difference voltage is not sufficient to detect the voltage sag. The proposed algorithm detects the sag voltage through all regions including the zero crossing voltage. Moreover, the exact voltage drop can be acquired by calculating the q-axis component that is proportional to the d-axis component. To verify the feasibility of the proposed system, the conventional and proposed methods are compared using simulations and experimental results.

• The Journal of the Korea Contents Association
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• v.14 no.8
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• pp.40-49
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• 2014

Globalisation has intensified the international movement of labour and South Korea is no exception. Korea, which in the past was itself a labour-exporting country, has seen a reversal in human mobility since the late 1990's with a rapid growth in immigration and a transformation of a previously almost ethnically homogenous society. In this context, the important questions about the cultural and political implications associated with the construction of minority representations in the media have remained highly unexplored. The starting point of this study is an examination of the vital role of public service broadcasting (PSB) in Korean society, where ethnic minorities have increasingly become visible. The study shows the significant role of PSB in representing cultural diversity in public debates and the ways in which such representations and their dissemination reflect media power.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.10
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• pp.965-975
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• 2005

In the case of the fault in stator windings of a high voltage motor. it facilitates certain destructive characteristics in insulations. This will result in a decreased reliability in power supplies and will prevent the generation of electricity, which will result in huge economic losses. This study simulates motor windings using normal windings and four faulty windings for an actual fault in stator winding of a high voltage motor. The partial discharge signals produced in each faulty winding were measured using an 80 PF epoxy/mica coupler sensor. In order to quantified signal waves its a way of feature extraction for each faulty signal, the signal wave of winding was quantified to measure the degree of skewness shape and kurtosis, which are both types of statistical parameters, using a discrete wavelet transformation method for each faulty type. Wave types present different types lot each faulty type, and the skewness and kurtosis also present different quantified values. The result of feature extraction was used as a preprocessing stage to identify a certain fault in stater windings. It is evident that the type of faulty signals can be classified from the test results using faulty signals that were randomly selected from the signal, which was not applied in the training after the training and learning period, by applying it to a back-propagation algorithm due to the supervising and learning method in a neural network in order to classify the faulty type. This becomes an important basis for studying diagnosis methods using the classification of faulty signals with a feature extraction algorithm, which can diagnose the fault of stator windings in the future.

• Journal of Ginseng Research
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• v.37 no.1
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• pp.108-116
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• 2013

For the improvement of ginsenoside bioavailability, the ginsenosides of fermented red ginseng by Phellinus linteus (FRG) were examined with respect to bioavailability and physiological activity. The polyphenol content of FRG ($19.14{\pm}0.50$ mg/g) was significantly higher (p<0.05) compared with that of non-fermented red ginseng (NFRG, $11.31{\pm}1.15$ mg/g). The antioxidant activities in FRG, such as 2,2'-diphenyl-1-picrylhydrazyl, 2,2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid, and ferric reducing antioxidant power, were significantly higher (p<0.05) than those in NFRG. The HPLC analysis results showed that the FRG had a high level of ginsenoside metabolites. The total ginsenoside contents in NFRG and FRG were $41.65{\pm}1.53$ mg/g and $50.12{\pm}1.43$ mg/g, respectively. However, FRG had a significantly higher content ($33.90{\pm}0.97$ mg/g) of ginsenoside metabolites (Rg3, Rg5, Rk1, compound K, Rh1, F2, and Rg2) compared with NFRG ($14.75{\pm}0.46$ mg/g). The skin permeability of FRG was higher than that of NFRG using Franz diffusion cell models. In particular, after 3 h, the skin permeability of FRG was significantly higher (p<0.05) than that of NFRG. Using a rat everted intestinal sac model, FRG showed a high transport level compared with NFRG after 1 h. FRG had dramatically improved bioavailability compared with NFRG as indicated by skin permeation and intestinal permeability. The significantly greater bioavailability of FRG may have been due to the transformation of its ginsenosides by fermentation to more easily absorbable forms (ginsenoside metabolites).

• The Journal of Korean Society for School & Community Health Education
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• v.2 no.2
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• pp.23-38
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• 2001

The purpose of this study was to suggest a stratege of promoting school health. This study examined the historical aspacts of school health and conducted a mail questionnaire survey for 24 school health specialists who work in school and educational administration from November 1 to November 30, 2000 and the reply rate was 79.2%(19 persons). The results were as follows. The most important fields in schools were answered health related field. The most important field of school health were health education(89.5%), the supervisor of school health project should be office of school health ward in Educational administration(42.1%), and problems in conducting health project in school were lack of policy(63.5%), awareness of the importance of school health(63.2%), and budget(63.2%). They answered that the cause of food poisoning in school were negligence of sanitation of cook(42.1%) and prevention methods were thorough inspection of food stuffs(31.6%). 72.2% replied that school health project were not being operated in a proper way. They answered that tasks of promoting school health were development of school health policy, increase of man-power for school health, expansion of school health budget, systematic health education, and development of independent health subject program, connection with local society. 94.7% of those replied answered that school health organization is necessary. Common sense on health and sex education are needs to be handled most importantly in health education. 63.2% of those replied answered that appropriate time of education for health service is more than once a week. The person appropriate for health education were school nurse(63.2%). In conclusion to improve the problems of school health and to activate it, development and support of policy of health project and preparation of various conditions that can establish health courses independently is, above all, immediately required. Many efforts need to be made to make the president of schools and education authorities recognize the importance of health in schools. These efforts need to link to the transformation of awareness, and process of development of concrete method of practicing various school health education and school health is necessary.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.8
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• pp.61-66
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• 2008

Recently, portable devices which require small area and low power consumption employ applications using 3D graphics such as 3D games and 3D graphical user interfaces. We propose an efficient clipping engine algorithm which is suitable in 3D graphics pipeline. The clipping operation is divided into two steps: one is the selection process in the transformation engine and the other is the pixel clipping process in the scan conversion unit. The clipping operation is possible with addition of simple comparator. The clipping for the Y-axis is achieved in the edge walk stage and that for the X and Z-axis is performed in the span processing. The proposed clipping algorithm reduces the operation cycles and the area of of 3D graphics pipelines. We designed a 3D graphics pipeline with the proposed clipping algorithm using Verilog-HDL and verifies the operation using an FPGA.

• Physical Therapy Korea
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• v.10 no.1
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• pp.109-128
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• 2003

This study tested whether repeated measurement of median frequency (MDF)-related variables could express the muscle power changes during a 12-week DeLome strengthening program, by using consecutive overlapping FFT (Fast Fourier transformation) and integrated EMG (IEMG) from surface EMG data for isometric and isotonic exercise. To evaluate the effect of training, the following were recorded every 3 weeks for the elbow flexors and knee extensors of 5 healthy male volunteers: MVC, lRM, limb circumference, and surface EMG during isometric MVC or isotonic contraction at 10RM load. From the EMG data, IEMG and variables from a regression analysis between MDF and time were obtained. MVC, lRM, IEMG, and initial MDF increased linearly over the training period. The fatigue index and slope of the regression line increased temporarily until the 6th week and decreased thereafter. From these results, there appeared to be enhanced neural recruitment of fast twitch fibers in the first 6 weeks and continued enhancement in the recruitment and hypertrophy of fast twitch fibers, which led to increased fatigue resistance, over the last 6 weeks. Accordingly, the MDF and IEMG analysis technique could demonstrate the effect of the program detected significant changes in both isometric and isotonic contractions. EMG analysis methods can be used to estimate the electrophysiological and histological changes in skeletal muscles during a strengthening program.

• The Journal of the Korea Contents Association
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• v.8 no.4
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• pp.108-116
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• 2008

Recently the advent of web 2.0 era is an important trend in the business environmental change. Web 2.0 era means users' active participation, share, and openness, develop 'Internet penetration into everyday life,' and change many aspects of our society. web 2.0 has been making these following changes in the socioeconomic aspects: 1) acceleration of system shift to a small quantity of multi-species production system 2) growing influence of on-line channel/information to consumers 3) various minorities' power increase in the socioeconomic sector. web 2.0 has been making these following changes in the enterprise management: 1) the pursuit of open innovation from outside 2) active employment of viral marketing through Internet 3) the pursuit of present business transformation 4) strengthening of customer communication through open dialogue. Firms must squarely look at socioeconomic changes owing to web 2.0, and utilize them as business opportunities.

• The Journal of the Acoustical Society of Korea
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• v.15 no.5
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• pp.82-89
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• 1996

Application fields of ultrasonic transducers can be divided into two categories, a high ultrasonic resolution required field and a high ultrasonic power required field. This paper is aimed to determine the optimal properties of the matching layers of the transducer for each of the applications. Further, it is aimed to optimize the properties of the matching layers that show satisfactory performances for both of the application fields. Through the direct time domain analysis of the transmission and reflection behavior of the ultrasonic wave, apart from the conventional equivalent circuit analysis, and Fourier transformation of its results, we found the optimum acoustic impedances of the matching layers. The newly determined layers provide much better transducer performance-57% at most-than those obtained with conventional design methods. Based on the results, we also found the optimal acoustic impedances of the layers good for both of the application fields. For te optimization, we developed a new transducer performance evaluation parameter that can be applied to any type of ultrasonic transducers.