• Journal of Technologic Dentistry
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• v.13 no.1
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• pp.37-51
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• 1991

In order to evaluate health status of dental technicians as an individual and a group, this study was conducted with Todai Health Index Questionaire on randomly sampled 277 persons(236 males and 41 females) from Aug. 20 to Oct. 6, in 1990 obtained Following conclusions were drawn. 1. Age composition of the subjects was 136 males(57.6%) in the age of 20$\sim$29 and 28 females(68.3%) in the age of 20$\sim$24. As for working places, 215 males(91.1%) and 38 females (92.7%) were working for dental laboratories and rest of them were at clinics and hospitals. In working years, male technicians who have been working for 5$\sim$10 years amounted to 80 (33.8%) and 12 females(29.3%) were working for 1$\sim$3years. 2. Responses to psychosomatic subjective symptom complaints rated as the highest in multiple subjective symptom(males : 40.00%, females : 41.98%) and those in physical items and mental irritability(male : 24%, female : 25%) and in mental items came next in order. The rate of complaint in depression was higher in female group than in male group (p<0.05). 3. Resonses to psychosomatic subjective symptom complaints in male group were high in the age of 20$\sim$29 and in the age of 20$\sim$24 in female group. The rates of complaint were higher in multiple subjective symptom, respiratory, eye and skin(p<0.05) and digestives(p<0.01) complaints. 4. Responses to psychosomatic subjective symptom complaints were higher among persons working at dental laboratories than at other working places : dental clinics and hospitals in all the items except for respiratory, depression and aggressiveness. Rates of complaints in eye and skin showed significant difference between working places(p<0.05). 5. Those who are engaged in polishing part tended to complain more about psychosomatic subjective symptoms. 6. The higher the level of education is the more they complained the psychosomatic subjective symptoms both in male and female group. In the difference of complaint respones, male group showed high rates of complaint in depression and female group in aggressiveness(p<0.05). 7. Responses to psychosomatic complaints by the length of working service were moderate in males who were working less than 10 years, and they decreased after 10 years of service. Females showed the highest response rate in the group of 3$\sim$5 years service and the lowest response in the group of 5 years service. Male complained more in aggressiveness and female in respiratory and aggressiveness(p<0.05). 8. Responses to psychosomatic subjective symptom complaint varied according to working hours of a day both in male and female group, showing high complaint rates in multiple subjective symptom, respiratory, eye and skin, mouth and anus, digestive, mental irritability and irregular life in male group(p<0.05).

• Journal of Food Hygiene and Safety
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• v.21 no.1
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• pp.23-30
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• 2006

Antimicrobial susceptibility and multiple drug resistance patterns have been carried out on total of 364 isolates of Salmonella enterica serovar Enteritidis isolated from foodborne patients in Seoul from 2001 to 2005. Overall, the highest percentage of resistance was found to the following antimicrobial agents: streptomycin (46.7%), ampicillin (37.3%), ticarcillin (36.7%), tetracycline (36.0%), nalidixic acid (20.7%), chloramphenicol (13.3%), amoxicillin/clavulanic acid (6.7%) and Ampicillin/sulbactam (4.0%). Seventy five percentage of isolates were found to be resistant to one or more of the antimicrobes tested. The resistant rates to nalidixic acid and chloramphenicol in S. Enteritidis tested were annually increased but the resistant rate to tetracycline was decreased and the resistant rates to streptomycin, ampcilin and ticarcillin were remained steadily. The most frequent patterns of multiresistant isolates were only nalidixic acid resistant (18.0%) and streptomycin-tetracycline (18.0%), streptomycin-ampicillin-ticarcillin (10%), and ampicillin-ticarcillin (5.5%). Overall the resistant rates of 1 drug was 19.3%,2 drugs 24.7%, 3 drugs 6.7% and 4 or more drugs 24.0%. The resistant rates of 1 drug and 2 drugs in 2005 were increased dramatically.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.8
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• pp.418-428
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• 2005

In this paper, a new probabilistic generation modeling method which can address the characteristics of changed electricity industry is proposed. The major contribution of this paper can be captured in the development of a probabilistic generation modeling considering generator maintenance outage and in the classification of market demand into multiple demand clusters for the applications to electricity markets. Conventional forced outage rates of generators are conceptually combined with maintenance outage of generators and, consequently, effective outage rates of generators are newly defined in order to properly address the probabilistic characteristic of generation in electricity markets. Then, original market demands are classified into several distinct demand clusters, which are defined by the effective outage rates of generators and by the inherent characteristic of the original demand. We have found that generators have different effective outage rates values at each classified demand cluster, depending on the market situation. From this, therefore, it can be seen that electricity markets can also be classified into several groups which show similar patterns and that the fundamental characteristics of power systems can be more efficiently analyzed in electricity markets perspectives, for this classification can be widely applicable to other technical problems in power systems such as generation scheduling, power flow analysis, price forecasts, and so on.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.804-806
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• 2005

In this paper, a new probabilistic generation modeling method which can address the characteristics of changed electricity industry is proposed. The major contribution of this paper can be captured in the development of a probabilistic generation modeling considering generator maintenance outage and in the classification of market demand into multiple demand clusters for the applications to electricity markets. Conventional forced outage rates of generators are conceptually combined with maintenance outage of generators and, consequently, effective outage rates of generators are new iy defined in order to properly address the probabilistic characteristic of generation in electricity markets. Then, original market demands are classified into several distinct demand clusters, which are defined by the effective outage rates of generators and by the inherent characteristic of the original demand. We have found that generators have different effective outage rates values at each classified demand cluster, depending on the market situation. From this, therefore, it can be seen that electricity markets can also be classified into several groups which show similar patterns and that the fundamental characteristics of power systems can be more efficiently analyzed in electricity markets perspectives, for this classification can be widely applicable to other technical problems in power systems such as generation scheduling, power flow analysis, price forecasts, and so on.

• Journal of Korean Academy of Rural Health Nursing
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• v.8 no.1
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• pp.33-41
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• 2013

Purpose: The study was done to explore relationships between residential areas and smoking rates and to identify related factors contributing to smoking in Korea adolescents. Methods: An analysis was done of smoking rates and socioeconomic position indicators by city size based on a 2012 cross-sectional nationwide online survey conducted with 74,186 Korean middle and high school students aged 12-18 years old. Data were analyzed using x2-test and multiple logistic regression with the SPSS/WIN18.0 program. Results: Analyses revealed that rural boys were more likely to be current smokers compared to metropolitan boys (odds ratio 1.18, 95%-confidence interval 1.01; 1.38) but residential areas and smoking rates among girls were not related. After adjusting for covariates, results showed that city size, Family affluence score, economic status, parents' education level, living with parents, school type, and school achievement were related to increased an proportion of adolescents who smoked. Conclusion: In conclusion, rural living is a determinant of smoking among boys. Tobacco control programs should recognize differences in living conditions between rural and urban areas.

• The Journal of the Acoustical Society of Korea
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• v.32 no.1
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• pp.86-94
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• 2013

In this paper, we propose a network coding scheme that is one of the most promising techniques for overcoming transmission errors in underwater acoustic communications. It is assumed that the proposed scheme operates in a Code Division Multiple Access (CDMA) network where multiple sensor nodes share the underwater acoustic channel in both the frequency and the time domains by means of orthogonal codes. The network topology deploys multi-hop transmission with relaying between multiple source nodes and one destination node via multiple relay nodes. The proposed scheme is evaluated in terms of the successful packet delivery ratio of end-to-end transactions under varying packet loss rates. A computer simulation shows that the successful delivery ratio is maintained at over 95% even when the packet loss rate reaches 50%.

• Journal of Information Processing Systems
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• v.13 no.3
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• pp.630-642
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• 2017

In this paper, we propose the opportunistic non-orthogonal multiple access (NOMA)-based cooperative relaying system (CRS) with channel state information (CSI) available at the source, where CSI for the source-to-destination and source-to-relay links is used for opportunistic transmission. Using the CSI, for opportunistic transmission, the source instantaneously chooses between the direct transmission and the cooperative NOMA transmission. We provide an asymptotic expression for the average achievable rate of the opportunistic NOMA-based CRS under Rayleigh fading channels. We verify the asymptotic analysis through Monte Carlo simulations, and compare the average achievable rates of the opportunistic NOMA-based CRS and the conventional one for various channel powers and power allocation coefficients used for NOMA.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.6
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• pp.587-592
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• 2005

Hydrolyzates from lignocellulosic biomass contain a mixture of simple sugars; the predominant ones being glucose, cellobiose and xylose. The fermentation of such mixtures to ethanol or other chemicals requires an understanding of how each of these substrates is utilized. Candida lusitaniae can efficiently produce ethanol from both glucose and cellobiose and is an attractive organism for ethanol production. Experiments were performed to obtain kinetic data for ethanol production from glucose, cellobiose and xylose. Various combinations were tested in order to determine kinetic behavior with multiple carbon sources. Glucose was shown to repress the utilization of cellobiose and xylose. However, cellobiose and xylose were simultaneously utilized after glucose depletion. Maximum volumetric ethanol production rates were 0.56, 0.33, and 0.003 g/L h from glucose, cellobiose and xylose, respectively. A kinetic model based on cAMP mediated catabolite repression was developed. This model adequately described the growth and ethanol production from a mixture of sugars in a batch culture.

• Journal of the Korean Data and Information Science Society
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• v.21 no.3
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• pp.569-574
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• 2010

We consider two components system which have Freund's bivariate exponential model. In this case, Bayesian multiple comparisons procedure for failure rates is sug-gested in K Freund's bivariate exponential populations. Here we assume that the com-ponents enter the study at random over time and the analysis is carried out at some prespeci ed time. We derive fractional Bayes factor for all comparisons under non- informative priors for the parameters and calculate the posterior probabilities for all hypotheses. And we select a hypotheses which has the highest posterior probability as best model. Finally, we give a numerical examples to illustrate our procedure.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.873-874
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• 2008

In this paper, we propose a packet loss concealment (PLC) algorithm for CELP speech coders, which is based on multiple adaptive codebooks by using comfort noise for the lost packet recovery. The multiple adaptive codebooks are composed of a conventional adaptive codebook to model periodic excitation of speech and another adaptive codebook to provide a better estimate of excitation when packets are lost in the speech onset region. The performance of the proposed PLC algorithm is evaluated by implementing it into the G.729 decoder and compared with that of the PLC algorithm employed in the G.729 decoder by means of perceptual evaluation of speech quality (PESQ). It is shown from the experiments under different burstiness of packet loss rates of 3% and 5% that the proposed PLC algorithm provides higher PESQ scores than the G.729 PLC algorithm.