• ETRI Journal
• /
• v.25 no.6
• /
• pp.437-444
• /
• 2003

We derive a new joint power and rate control rule with which we can minimize the mean transmission delay in CDMA networks for a given mean transmission power. We show that it is optimal to respectively control the power inverse-linearly and the rate linearly to the square root of channel gain while maintaining the signal-to-interference ratio at a constant. We also show that the proposed joint power/rate control rule achieves excellent performance results in terms of the probability of the instantaneous delay being within a target delay against one-dimensional control schemes.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.23 no.3
• /
• pp.483-494
• /
• 1999

This study investigated the relation between seasonal variation of clothing weight and its resting metabolic rate to determine the relation between proper living temperature and cold/heat tolerance. Thirty six subjects(18 males and females twenties) were composed to obtain the clothing weight(Total clothing weight) and resting metabolic rate for a year and grouped four seasons : spring (Mar-May) Summer(Jun-Aug) Fall(Sep-Nov) and Winter(Dec-Feb). The data of males and females were respectively divided into three groups by cluster analysis with clothing weight. 1. The resting metabolic rate of male(41.1kcal/m2/hr) was higher than that of female(33.2kcal/m2/hr). It is suggested there is gender difference in the resting metabolic rate(p<.001) 2. The resting metabolic rate of male and female was the highest in Winter. It is suggested there is seasonal variation in the resting metabolic rate(p<.001) 3. It was found that there was relation between clothing weight and resting metabolic rate. The difference of resting metabolic rate between Summer and Winter which is profitable to adaptation to living temperature was significant in light clothing weight in male as well as in female. 4. In comfortable sensation most subjects responded that he/she felt 'comfortable' except Winter. However the heavy clothing weight group felt 'a little uncomfortable' throughout all seasons. l In thermal sensation most subjects responded that he/she felt 'neutral' And then the heavy clothing weight group responded warmer in summer and cooler in winter than light clothing weight group. From the results it was confirmed that male and female showed seasonal variations in clothing weight and resting metabolic rate. Also the resting metabolic rate of male and female was influenced by the clothing weight. In short seasonal variation of resting metabolic rate was larger in light clothing weight group than in heavy clothing weight group. Therefore light clothing weight group is advantgeous in living temperature to improve cold/heat tolerance and it also shows that living with the light clothing weight may enhance the degree of adaptation to change of living environment

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.35S no.11
• /
• pp.37-43
• /
• 1998

This paper proposes a new echo canceller that can be used in a full-duplex digital subscriber loop modem. The proposed echo canceller uses a NLMS-based parallel adaptation NLMS (PA-NLMS) algorithm. The PA-NLMS algorithm that an estimate of the nonstationarity to additive noise ratio (NNR) gained from two distinct NLMS processes is used to select the value of NLMS convergence-controlling parameter has been developed. Numerical results based on computer simulation show that the proposed algorithm has a convergence rate approaching that of the fastest possible NLMS process while improving on its MAC performance considerably.

• Phonetics and Speech Sciences
• /
• v.6 no.1
• /
• pp.77-83
• /
• 2014

This paper proposes a speaker and environment clustering method in order to overcome the degradation of the speech recognition performance caused by various noise and speaker characteristics. In this paper, instead of using the distance between Gaussian mixture model (GMM) weight vectors as in the Google's approach, the distance between the adapted mean vectors based on the modified maximum a posteriori (MAP) adaptation is used as a distance measure for vector quantization (VQ) clustering. According to our experiments on the simulation data generated by adding noise to clean speech, the proposed clustering method yields error rate reduction of 10.6% compared with baseline speaker-independent (SI) model, which is slightly better performance than the Google's approach.

• Journal of Korea Multimedia Society
• /
• v.9 no.12
• /
• pp.1560-1571
• /
• 2006

In order to transmit multimedia streams over the network with a timely changing channel bandwidth such as Internet, scalable video coding schemes have been studied to represent video in flexible bitstream. Much research has been made on how to represent encoded media(such as video) bitstream in scalable ways. In this paper, rte propose an optimal selection of the objects for MPEG-4 bitstream adaptation to meet a given constraint. We adopt a multiple choice knapsack problem with multi-step selection for the MPEG-4 objects with different bit-rate scaling levels in the MPEG-4 bitstream. The bitstream adaptation based on the optimal selection result is then to fetch the necessary parts of the MPEG-4 bitstream to constitute an adapted version of the original MPEG-4 binary resource. The experiment results show that the optimal selection of MPEG-4 objects for a given constraint can promisingly be made which meets the given constraint.

• Proceedings of the KSPS conference
• /
• 2003.05a
• /
• pp.83-86
• /
• 2003

This paper presents our style-based language model adaptation for Korean conversational speech recognition. Korean conversational speech is observed various characteristics of content and style such as filled pauses, word omission, and contraction as compared with the written text corpora. For style-based language model adaptation, we report two approaches. Our approaches focus on improving the estimation of domain-dependent n-gram models by relevance weighting out-of-domain text data, where style is represented by n-gram based tf*idf similarity. In addition to relevance weighting, we use disfluencies as predictor to the neighboring words. The best result reduces 6.5％ word error rate absolutely and shows that n-gram based relevance weighting reflects style difference greatly and disfluencies are good predictor.

• Proceedings of the KSPS conference
• /
• 2003.05a
• /
• pp.123-126
• /
• 2003

We discuss how to reduce the number of inverse matrix and its dimensions requested in MLLR framework for speaker adaptation. To find a smaller set of variables with less redundancy, we employ PCA(principal component analysis) and ICA(independent component analysis) that would give as good a representation as possible. The amount of additional computation when PCA or ICA is applied is as small as it can be disregarded. The dimension of HMM parameters is reduced to about 1/3 ~ 2/7 dimensions of SI(speaker independent) model parameter with which speech recognition system represents word recognition rate as much as ordinary MLLR framework. If dimension of SI model parameter is n, the amount of computation of inverse matrix in MLLR is proportioned to O($n^4$). So, compared with ordinary MLLR, the amount of total computation requested in speaker adaptation is reduced to about 1/80~1/150.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.5
• /
• pp.742-747
• /
• 2007

In order to investigate the mechanism of adaptation to long-term heat stress, six female buffalo calves of about 7 to 8 months age, were exposed to the cool-comfort environment (THI 65) for 21 days to obtain normal values of blood acid-base. An adaptive response of acid-base regulation was determined to long term (21 days) exposure of buffalo calves to hot-dry (THI 80) and hot-humid (THI 84) conditions. Higher rectal temperature and respiratory rate was recorded under hot-humid exposure compared to hot-dry. Significant reduction in the rectal temperature and respiratory rate on day 21 of hot-dry exposure indicated early thermal adaptation compared to hot-humid. Decreasing rectal temperature and respiratory rate from day 1 to 21 was associated with concurrent decrease in blood pH and pCO2. Increased plasma chloride concentration with low base excess in blood and in extracellular fluid suggested compensatory response to respiratory alkalosis. Reduced fractional excretion of sodium with increased fractional excretion of potassium and urine flow rate indicated renal adaptive response to heat stress.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.7C
• /
• pp.921-930
• /
• 2004

In this paper, a robust video transmission system is proposed. To effectively prevent the corruption of video stream and its propagation in spatial and temporal domains, a version of turbo code, so-called as byte-aligned variable-length turbo code, is applied. Protection performance of the proposed turbo code is first evaluated by applying it to GOB-based variable-size ITU-T H.263+ video packets, where the protection level is statically controlled based on the joint source-channel criteria. This protection is then extended to support the adaptation of code ratio to best match the time-varying channel condition. The time-varying Rayleigh fading channel is modelled considering the correlation of the fading channel. The resulting performance comparison with the static turbo code as well as the conventional RCPC code clearly demonstrates the possibility of the proposed adaptation approach for the time-varying correlated Rayleigh-fading channel.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.23 no.2
• /
• pp.389-400
• /
• 1996

In Class II amalgam restoration in deciduous molar, failure rate and incidence of recurrent caries are high as children become older. In order to preserve deciduous molars till the physiologic exfoliation time, stainless steel crown is a choice of the treatment. As a result of a careless treatment, such as overhanging margin, poor marginal adaptation, poor proximal contour and inadequate mesiodistal width give rise to interfering eruption of the adjacent teeth, recurrent caries and chronic gingival irritation and insufficient arch length respectively. In this study, 252 s.s. crowned teeth extracted due to physiologic exfoliation or periapical lesion. The purpose of this study is to analyze the marginal adaptation of stainless steel crown to the deciduous molar in order to obtain better clinical result. The results were as follows : 1. Between the length of s.s. crown and the marginal gap of crown, positive correlations were shown. 2. Largest amount of marginal gap was shown at buccal side in upper deciduous molars and lower first deciduous molar, lingual side in lower second deciduous molar. But no significant diffrence were found statistically compared to second most largest one. 3. Incidence of exposed restoration and recurrent caries were higher in proximal surface than buccal/lingual surface. And extension of restoration below the margin of s.s. crown gives rise to higher rate of recurrent caries. 4. Defect of contour was found in 34%, frequently found in lower 1st deciduous molar and upper 1st deciduous molar. 5. Marginal polishing defects were found in 23%. 6. Ledge was formed in 10% especially in lower 1st deciduous molar and lower 2nd deciduous molar. 7. 16% of the teeth had wear facet due to traumatic occlusion, 7% of them had occlusal perforation.