• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.285-289
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• 1999

Insulation diagnosis techniques of power equipments for the stable power supply and prevention from accidents are of high importance. Diagnosis techniques is able to prevent from large accidents before they happen by finding signs of the accidents. From this point of view, this paper simulated discharge progress and partial discharge using needle-plan electrode system in air, studied the distribution of frequency spectrum of the radiated electromagnetic waves using biconical antenna and spectrum analyzer. From results of this study, the new method was introduced for measurement and analyzation of the radiated electromagnetic waves in accordance with discharge progress in air, Besides, according to the consideration of the mutual relation between frequency spectrum of the radiated electromagnetic waves and discharge progress, it was confirmed that detecting partial discharge and estimating discharge progress were possible.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.1
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• pp.169-174
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• 2011

For a double-walled carbon nanotube resonator with a short outer nanotube, the free edge of the short outer wall plays an important role in the vibration of the long inner nanotube. For a double-walled carbon nanotube resonator with a short inner nanotube, the short inner nanotube can be considered as a flexible core, thus, the fundamental frequency is influenced by its length. In this paper, we analysis frequency variation in ultrahigh frequency nanomechanical resonators based on double-walled carbon nanotubes with different wall length. This results will widely apply to the realization of frequency devices controlling the length of the inner or outer nanotube.

• International Journal of Computer Science & Network Security
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• v.24 no.2
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• pp.95-100
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• 2024

Cyclic Delay Diversity (CDD) is a diversity scheme used in OFDM-based telecommunication systems, transforming spatial diversity into frequency diversity and thus avoiding intersymbol interference without entailing the receiver to be aware of the transmission strategy making the signal more reliable achieving full diversity gain in cooperative systems. Here the analyzation of the influence of CDD-SC scheme in Cognitive Radio Network (CRN) is done with the challenge of overcoming the complication called channel estimation along with overhead in CNR. More specifically, the closed-form expressions for outage probability and symbol error rate are divided under different frequencies among independent and identically distributed (i.i.d.) frequency selective fading channel model i.e., the signal is divided into different frequencies and transmitted among several narrow band channels of different characteristics. It is useful in the reduction of interference and crosstalk. The results reveal the diversity order of the proposed system to be mainly affected by the number of multipath components that are available in the CNR.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.2
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• pp.81-87
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• 2003

This paper simulated discharge progress and partial discharge using needle-plan electrode system in air, in this time with discharge progress, studied the distribution of frequency spectrum of the radiated electromagnetic waves using biconical antenna and spectrum analyzer. From results of this study, a method was introduced for measurement and analyzation of the radiated electromagnetic waves in accordance with AC discharge progress in air, Besides, according to the consideration of the mutual relation between frequency spectrum of the radiated electromagnetic waves and discharge progress, it was confirmed that detecting partial discharge and estimating discharge progress were possible.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2245-2247
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• 1999

Insulation diagnosis techniques of power equipments for the stable power supply and prevention from accidents are of high importance. Diagnosis techniques is able to prevent from large accidents before they happen by finding signs of the accidents. From this point of view, this paper simulated discharge progress and partial discharge using needle-plan electrode system in air, studied the distribution of frequency spectrum of the radiated electromagnetic waves using biconical antenna and spectrum analyzer. From results of this study. the new method was introduced for measurement and analyzation of the radiated electromagnetic waves in accordance with discharge progress in air. Besides, according to the consideration of the mutual relation between frequency spectrum of the radiated electromagnetic waves and discharge progress, it was confirmed that detecting partial discharge and estimating discharge progress were possible.

• Convergence Security Journal
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• v.8 no.1
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• pp.129-141
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• 2008

This paper analyzes repairing methods in terms of symptoms of hard disk through maker's knowhow and skill from experience. However, though an user tries this method, if the user is not skilled person, it can be failed. A defect Hard disk should be diagnosed and treated carefully. And also it should be executed after enough practice. This analyzation was tried by examination with the naked eye, sound, and the frequency of symptoms. And the result can be precious data for restoration of critical evidence.

• Journal of Family Resource Management and Policy Review
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• v.1 no.1
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• pp.57-70
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• 1997

The purpose of this study is to analyze housewives’ cognition, usage, and management behavior of credit cards according to home management behavior pattern. The sample of this study was selected from the housewives’ living in Seoul who has credit cards. After class-analyzation of the sample, 523 out of 612 repondents were finally selected data. The data were analyzed by the statical methods such as frequency, mean, percentile, Factor Analysis, t-test, ANOVA, Duncan’s multiple range test, Person’s Correlation, and Multiple Regression Analysis through the SAS program package. The major findings of this study are as followers : First, housewives’ usage and management behavior of credit cards was a positive relationship between home management behavior pattern. Second, housewives’ cognition of credit cards showed a significant positive relationship with usage and management behavior of credit card. Third, the most influencial variables on housewives’usage and management behavior of credit cards were their value and home management behavior pattern.

• Journal of Broadcast Engineering
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• v.23 no.3
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• pp.421-430
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• 2018

Many voice recognition systems use methods such as MFCC, HMM to acknowledge human voice. This recognition method is designed to analyze only a targeted sound which normally appears between a human and a device one. However, the recognition capability is limited when there is a group sound formed with diversity in wider frequency range such as dog barking and indoor sounds. The frequency of overlapped sound resides in a wide range, up to 20KHz, which is higher than a voice. This paper proposes the new recognition method which provides wider frequency range by conjugating the Wideband Sound Spectrogram and the Keras Sequential Model based on DNN. The wideband sound spectrogram is adopted to analyze and verify diverse sounds from wide frequency range as it is designed to extract features and also classify as explained. The KSM is employed for the pattern recognition using extracted features from the WSS to improve sound recognition quality. The experiment verified that the proposed WSS and KSM excellently classified the targeted sound among noisy environment; overlapped sounds such as dog barking and indoor sounds. Furthermore, the paper shows a stage by stage analyzation and comparison of the factors' influences on the recognition and its characteristics according to various levels of noise.

• Journal of the Korean Society of Radiology
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• v.10 no.4
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• pp.247-253
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• 2016

Ultrasound devices diagnose many disease, which is widely used, can not be standardized quantitative evaluated in order to evaluate sonography image of quality. Therefore, in this papers, aims to get correct image in order to accurate diagnosis by figuring out the appropriate parameter based on each target by measuring distortion which results in the analyzation of the sensitivity of SNR and the histogram of signal by manipulating parameter of 8 mm target in ATS-539 multipurpose phantom. Equipment using Acuson sequoia 512, convex probe and utilizes multi-objective phantom. experiment method is that first you put the phantom on the flat and acquire 85 sheets of image, changing frequency(2,3,4 MHz, harmonic 3, 4, 4.5 MHz), Focus(2, 4, 6 unit), and Dynamic Range(58, 68, 78, 88, 98) for a 8 mm structure. through the Image J program. The sensitivity angle of 8mm target through Image J program is gauged by each separate target SNR and the distorted angle subtract and measure Histogram of background from Histogram of signal and take top 40% from the given result value above. According to parameter variation we found out proper parameter by acquiring SNR of sensitivity and distortion data for aspect of transition. The more this findings have Focus, the lower distortion value and at 4 MHz frequency this result have high SNR and low distortion value. Dynamic Range got an appropriate image on 88 and 98. It is considered on the basis of the experimental data, the probability of disease diagnosis will get higher.

• Korean Journal of Health Education and Promotion
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• v.22 no.4
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• pp.245-256
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• 2005

The purpose of this study is to research the situation and related knowledge and behavior of Korean beauty artists on their musculoskeletal disorders and the factors on them. It was researched by questionnaire from March 1 to May 31, 2003, and the subjects were 984 of beauty artists who were working as hair designers, skin care specialists, and make-up artists over 1 year in big cities including Seoul, Daegu, Busan and Gwangju. The analyzation was done by frequency, percentage, $x^2-test$, t-test. The results can be summarized as follows; 1. As for their degree of pain according to part of their body, the highest was shoulder as 88.3%, and next were neck(cervical region) as 83.2%, waist as 77.6%, and wrist(hand) as 71.8%, in order. 2. The level of knowledge on the muscloskeletal disorder was 65.6 points on the basis 100points. As for their level of protective behavior and knowledge on the disorders of musculoskeletal system according to their educational experience, the higher educational level they had the higher knowledge level they showed, as 42.6% of 'high', 30.4% of 'medium', and 27.0% of low; and as for degree of performing the protective behavior, they showed the higher protective behavior level when they had the higher educational level. 3. As for their level of knowledge on disorders of musculoskeletal system according to their general uniqueness as beauty artists, they showed statistical significance on the field of their marriage status, educational degree, specialized field, and numbers of customers they manage; and as for the degree of their protective behavior, they showed statistical significance in the field of age, marriage status, specialized field, and rank in their jobs. 4. The level of protecting behavior on the muscloskeletal disorder was 57.4 points on the basis 100points. As for their degree of pain on each part of their body according to their protective behavior and knowledge on musculoskeletal system, it had statistical significance on their elbows and hips, and the less pain they showed when the higher knowledge they had; it had statistical significance on their neck(cervical region), shoulders, backs, waists, knees and ankles(feet) according their protective behavior, and the less pain they showed when the higher level of protective behavior they did.