• Journal of Broadcast Engineering
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• v.2 no.1
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• pp.8-15
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• 1997

In this paper, a real-time operating Motion Picture Experts Group-1 (MPEG-1) audio encoder system is implemented using a TMS320C31 Digital Signal Processor (DSP) chip. The basic operation of the MPEG-1 audio encoder algorithm based on audio layer-2 and psychoacoustic model-1 is first verified by C-language. It is then realized using the Texas Instruments (Tl) assembly in order to reduce the overall execution time. Finally, the actual BSP circuit board for the encoder system is designed and implemented. In the system, the side-modules such as the analog-to-digital converter (ADC) control, the input/output (I/O) control, the bit-stream transmission from the DSP board to the PC and so on, are utilized with a field programmable gate array (FPGA) using very high speed hardware description language (VHDL) codes. The complete encoder system is able to process the stereo audio signal in real-time at the sampling frequency 48 kHz, and produces the encoded bit-stream with the bit-rate 192 kbps. The real-time operation capability of the encoder system and the good quality of the decoded sound are also confirmed using various types of actual stereo audio signals.

• Journal of Preventive Medicine and Public Health
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• v.33 no.1
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• pp.36-44
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• 2000

Objective : The heart diseases are known as a major cause of sudden death, as well as a cause of poor life-quality of school-age children. But there have been few mass screening of heart diseases in these children in Korea. This study was done to estimate the prevalence of heart diseases of these population. Methods : We screened all elementary students(grade 1) in 12 cities and 16 counties(Gun) in Kyonggi province from 1992 to 1955. The first screening was done by auscultation of doctors and simultaneously by checking using 'auto-interpreter of EKG-cardiac sound' (Fukuda Densi ECP 50A). We conducted luther examinations to whom classified as being abnormal condition in first screening, by using EKG, chest x-ray, doppler echocardiograpy(if needed). Results : The total number of examined students was 161,308(92% of the population), the male were 83,238 and female were 78,070. The congenital heart diseases(CHD) patients were 290(18 per 10,000) - male 155(18.6 per 10,000) and female 135(17.3 per 10,000). The most frequent disease was ventricula septal defect(VSD, 45.5%), Atrial septal defect(ASD, 14.8%), Tetralogy of Follot(TOF, 11.7%), and Patent Dutus Arteriosis(PDA, 7.6%) in order. In female, the order was VSD(48.1%), ASD(13.3%), TOF(11.1%), and PDA(10.4%). The total number of EKG abnormality were 433(62.7 per 10,000) among 69,056 screened children in 1995. The complete right bundle branch block(CRBBB) and paroxymal ventricular contraction(PVC) were frequent(26.6%, 26.3% in each), and incomplete right bunddle branch block(IRBBB, 14.6%), paroxymal atrial contraction(PAC, 6.7%), abnormal Q(5.8%), Wolf-Pakinson-White syndrom (5.5%) in order. In female, the most frequent abnormality was PVC(29.8%), and CRBBB(19.9%) in order. Conclusion : We could present the stable prevalence of the rare heart disease. The prevalence of congenital heart diseases was 18.0 per 10,000 and of EKG abnormality was 62.7 per 10,000 among school children.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.19 no.1
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• pp.11-15
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• 2008

Endoscopic laser cordectomy is known as an oncologically sound procedure for T1 and selected T2 glottic carcinoma ; it has comparable local control rate and better long-term laryngeal preservation rate when compared with those of radiotherapy. Even if results of the reported voice outcome studies after surgery or radiotherapy are diverse and controversial, resection deeper than the body layer of the vocal fold (type III, IV, V cordectomy) usually leads to aerodynamic insufficiency during phonation and results in poor voice quality. A keyhole defect or development of synechiae at the anterior commissure after type VI cordecomy may also result in unsatisfactory vocal outcome. However, many advances in phonosurgical techniques are reported to be successfully applied in the reconstruction of glottal defect that is subsequent to endoscopic laser cordectomy. In case of glottal insufficiency, voice restoration can be achieved by means of augmentation of the paraglottic space or medialization of the excavated vocal fold. Injection laryngoplasty with synthetic materials or autologous fat is gaining its popularity for restoring minor glottal volume defect because of its convenience. Laryngeal framework surgery, especially type I thyroplasty with premade implant systems or Gore-Tex, is most frequently used to correct larger glottic volume defect. In case of anterior commissural keyhole defect, additional procedure including laryngofissure may be required. For anterior commissural synechiae, laryngeal keel may be inserted for several weeks or mitomycin-C may be repeatedly applied after the division of adhesive scar to prevent restenosis. In this paper, current concepts and the authors' experiences of phonosurgical reconstruction of vocal function after endoscopic cordectomy will be introduced.

• Journal of Korea Society of Industrial Information Systems
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• v.13 no.5
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• pp.117-123
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• 2008

In this paper, we develop MPEG-4 AAC streaming player on embedded Linux processor such as mobile terminals. Moreover we show the experimental results that the player preforms the decoding processes of MPEG-4 AAC data effectively. MPEG-4 AAC technology supports a wide range encoding rates and high sound quality so it is appropriate to adopt various applications. In particular, the need in the development of the application of audio data increases according to significantly increase in devices used in mobile environments, such as cell phones and PDAs. In this environment, it is necessary to optimize the decoding processes to the ability of the terminal hardware in order to play audio data without delays. We also implement the decoding module to optimize the processor capabilities and make the player to decode and play streaming audio data from streaming server.

• Transactions of Materials Processing
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• v.16 no.4 s.94
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• pp.293-298
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• 2007

Recently, there is a need to produce a large forged part for the flight, shipping, some energies, and military industries, etc. Therefore, an open die forging technique of cast ingots is required to obtain higher quality of large size forged parts. Cogging process is one of the primary stages in many open die forging processes. In the cogging process prior to some open die forging processes, internal cavities have to be eliminated for defect-free. The present work is concerned with the elimination of the internal cavities in large ingots so as to obtain sound products. In this study, hot compression tests were carried out to obtain the flow stress of cast microstructure at different temperature and strain rates. The FEM analysis is performed to investigate the overlap defect of cast ingots during cogging stage. The measured flow stress data were used to simulate the cogging process of cast ingot using the practical material properties. Also the analysis of cavity closure is performed by using the $DEFORM^{TM}-3D$. The calculated results of cavity closure behavior are compared with the measured results before and after cogging, which are scanned by the X-ray scanner. From this result, the criteria for deformation amounts effect on the cavity closure can be investigated by the comparison between practical experiment and numerical analysis.

• Journal of Korea Water Resources Association
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• v.43 no.11
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• pp.957-965
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• 2010

The municipal water is directly related to the people's quality of life. To examine and implement reasonable water policies including management of the water demand and economically sound investment decisions, it is essential to estimate the conceptually correct and empirically valid economic value of water. This study attempts to estimate the consumer surplus and economic value of municipal water which is supplied to 16 cities in Korea using demand curve approach. The results indicate that the consumer surplus and economic value of municipal water in 2009 are estimated as KRW 1,180.7 per $m^3$ and KRW 1,812.8 per $m^3$, respectively. The economic values of municipal water in 16 cities range from KRW 1,082.7 per $m^3$ to KRW 3,268.6 per $m^3$. Moreover, the economic value of non-residential water is higher than that of residential water in all cities, and the economic value of water is higher than the present price of water. This study is expected to provide policy-makers with useful information to assess a policy and to evaluate the price of water.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.27 no.3
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• pp.193-210
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• 1991

For the deckhouse or superstructure, attention is directed to the reduction of vibration from a human susceptibility point of view. The two basic requirements for obtaining a low vibration level in the accommodation are to ensure that excitation forces from propeller and/or main engine are small and to avoid resonance excitation of the hull and superstructure. In recent years increased attention has been directed towards the problems of vibration and noise in deckhouse, which have caused major problems with regard to the environmental quality in the living quarters for crews. Accordingly, in this paper, the characteristic of the vibration of deckhouse of fishing boat, of which the length/height ratio is also relatively high, are studied systematically with regard to the shape and modelling of deckhouse based on finite element method of 1-dimensional, 2-dimensional and 3-dimensional model. This study is divided into 4-part. 1st part is the global deckhouse vibration, 2nd part is the local deckhouse vibration, 3rd part consists of the estimation for stiffness of foundational support and 4th part is the application to TUNA LONG LINER of 416 ton class. For the global vibration analysis, the severity of the vibration depends on the longitudinal shear and bending stiffness of the deckhouse, on the vertical deckhouse support(fore, aft and sides). However, even if the design is technically sound, vibration problems may arise due to vertical or longitudinal hull girder or afterbody resonances. Author applied the method of this study to the analysis of, deep-sea fishing vessel of G.T. 416 ton class with relatively low height and long deckhouse, and investigated the vibrational characteristic of the fishing vessel with earlier structural feature. According to this investigation, the vibration, response of above vessel was confirmed of which main hull and deckhouse behave as one body. It is at the bottom of vibrational trouble which a accommodation part of the fishing vessel is raised, that is the local vibration for side wall, fore-aft wall and deck plate of deckhouse rather than thief fect of fore-aft vibration of deckhouse for above fishing vessel. and the resonance of main hull, deckhouse and driving system such as the main engine, propeller in exciting source is mainly brought up as the trouble.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.2
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• pp.257-265
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• 2017

In this work, the effect of field-degradation of automotive polymeric interior parts on the squeak characteristics was studied for a number of used vehicles with various mileages and years of service. The purpose of this study was to characterize the squeak noise related with long-term degradation in service life. The characteristics of field-degraded polymeric samples are analyzed using Fourier transform infrared(FT-IR) spectroscopy and scanning electron microscopy(SEM). Complicated carbonyl spectra from FT-IR were deconvoluted into various carbonyls to trace field-degradation phenomenon. In addition, various mechanical tests, i.e. tensile test, hardness test as well as coefficient of friction test, were performed to analyze the variation in mechanical properties due to field-degradation. Squeak noise was measured and analyzed by frequency analysis. It was shown that the changes in the chemical structures of polymer due to field-degradation influenced the variation in mechanical properties, and squeak noise may worsen by increasing the squeak noise level in the wide frequency range. The results indicated that customer complaints regarding the squeak noise coming from used vehicles might be one of the important reliability issues because the increase in sound pressure level especially in the high frequency range could annoy drivers and passengers.

• Journal of Information Technology Applications and Management
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• v.14 no.4
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• pp.159-174
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• 2007

The purpose of this research is to investigate the relationships among the perceived satisfaction, the perceived the trust, the commitment, the key features for mobile phone, the brand image, the switching cost and the repurchasing intention. We also examine the differences between Korean and Indonesian markets concerning the relationships of these key successfactors. The structural model is tested with the data form each of the sub-samples (i. e. Korean and Indonesian users taken separately). Properties of the casual paths, including standardized path coefficients, the significance of difference, and variance explained for trust, satisfaction, commitment and repurchasing in the hypothesized model, are presented. This study indicated that hardware (sound quality, LCD display, design) user interface (GUI, Menu, Key pad) and extra functions (camera phone, wireless internet, MP3 player) are the three important factors effecting the trust and the satisfaction. The proposed model has been newly tested from the technological prospective in order to get the more practical result. Following the model test, we conduct a test of the differences in path coefficients between Korean and Indonesian users. MSEM show that, compared to Korean market, Indonesian had more emphasized on extra-function for the mobile phone as well as giving more influence to the satisfaction from the brand image. It means Korean market consider the extra-function as basic or no-premium points. And the satisfaction has been effected by switching-cost in Korea but the trust in Indonesia. Other interesting result from the structural weight invariance indicate that, compared to Korean market, the brand-image has effected the satisfaction in addition to placing more the trust on determining the commitment in Indonesia.

• The Journal of the Korea Contents Association
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• v.18 no.1
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• pp.587-595
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• 2018

This research aims to analyze the importance-performance among multiplex cinema selection attributes. Therefore, we collected data for visitors who visited the multiplex cinema and want to watch movies. Of the various multiplex cinema selection attributes, four factors were deduced that includes: major services, human services, physical environment, auxiliary services using exploratory factor analysis. In the quadrant I, the area of 'Concentrate Here' was 'diversity of screening time', 'diversity of movie genre', 'convenience of mobile app use', 'size and convenience of parking facility'. In the quadrant II, 'Keep up the Good Work' area was 'convenience of website booking', 'discounts through card partnerships', 'employee friendliness', 'accurate employee information delivery', 'comfortable seating', 'screen size', 'cinematic sound quality', and 'convenience of traffic' etc. The quadrant III, 'Low Priority' appeared to be 'membership system', 'tidiness of staff attire', 'resting space for waiting time', 'accessibility to the neighboring area', 'diversity of the snack corner', and 'overall cleanliness' etc. The quadrant IV, 'Possible Overkill' was 'appropriateness of the auditorium temperature' and 'service proficiency'.