• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.3
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• pp.186-195
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• 2018

Purpose: We performed quantitative and qualitative analysis of typical periodontal bacteria using real time PCR method to investigate the microbiological difference according to the severity of peri-implant disease in Koreans. Materials and Methods: Total of 60 implants were divided into three groups (healthy group, peri-implant mucositis group, peri-implantitis group) through periapical radiographs and clinical indices. The evaluated clinical parameters were pocket depth, plaque index, suppuration and bleeding on probing. Using a sterilized curette instrument, microbial samples were collected from the subgingival plaque and real-time PCR was performed on five periodontal bacteria. The relative expression levels of microorganisms were compared by comparative delta-CT method. Results: The relative expression levels of E. corrodens and T. denticola were significantly higher in the peri-implantitis group (P < 0.017). On the other hand, the relative expression level of F. nucleatum and P. gingivalis was relatively high in the healthy implant group regardless of the severity of disease. P. intermedia was significantly lower in the healthy implant group (P < 0.017). Conclusion: Periodontal bacteria were detected in Koreans with peri-implant diseases, but there was no microbiological distribution similar to periodontitis.

• Journal of Biosystems Engineering
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• v.11 no.1
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• pp.52-63
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• 1986

This study was performed to find out drying characteristics and develop drying model for the design of an efficient dryer or drying system of red peper. The basic model which describes drying phenomenon of red pepper was firstly established, and drying tests were conducted at 14-different drying conditions. In this test, the effects of drying air temperature and relative humidity on the rate of drying were undertaken. Finally, a new drying model based on these experimental results was developed to describe the drying characteristics of red pepper. The results from this study may be summarized as follows. 1. Drying constant of the basic model established from Lewis' experimental model and diffusion equation was theoretically deduced as a function of moisture content and inner-temperature of red pepper. 2. From the results of drying tests, drying air temperature was found to have the greatest effect on the rate of drying. However, the effect of temperature was small for the condition of high relative humidity, and for low temperature, the effect of relative humidity was found to be large even though the range of relative humidity was low. 3. Modified Henderson equation was found to be better than Chung equation as the EMC model for the estimation of the equilibrium moisture content of red Pepper. 4. Constant-rate drying period did not exist in the red pepper drying test. And falling-rate drying period was divided into three distinct phases. Drying rate was dependent on the moisture content, the inner-temperature of red pepper and the change of physical property due to drying. 5. Drying constant increased with decrease of free moisture content, but it decreased at the end of the drying period. Also, drying constant was dependent on the drying air temperature and relative humidity. 6. The new drying model developed in this study was found to be most suitable in describing the drying characteristics of red pepper. Therefore, it may be concluded that drying time could be accurately estimated by the new drying model.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1D
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• pp.1-10
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• 2010

Safety improvement has been a continuous challenge, especially at toll gate of express highway where traffic conflict often occurs due to frequent lane change by drivers of "Hi-pass" lane and regular "TCS" lane. As a part of research on safety at toll gate, this study videotaped traffic conflict data between vehicles using centrally located "Hi-pass" lane and regular "TCS" lane and analyzed accident risk. According to the correlation analysis of vehicle speed, relative vehicle speed, and sudden vehicle deceleration rate due to traffic conflict, when the relative vehicle speed between centrally located "Hi-pass" lane and regular "TCS" lane increases, sudden vehicle deceleration rate also increases. One of the findings is that centrally located "Hi-pass" lane at toll gate shows different location for traffic conflict, and frequency of traffic conflict and the relative vehicle speed was also different based on vehicle lane use. TA (Time to Accident) analysis shows that accident rate is high at toll gate where Hipass lane is installed in center lane, when the occurrence of sudden vehicle deceleration and deceleration time of vehicles rise for vehicles on "Hi-pass" lane. Furthermore, if the expressway entrance/exit point is closely located to toll gate, TA showed a low value. Thus, it is necessary to reduce the relative vehicle speed in order to improve safety. The Study presents reduction of the relevant vehicular speed and prevention of accidents at the centrally installed "Hi-pass" lane as an important strategy for safety improvement at toll gate.

• The Korean Journal of Applied Statistics
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• v.28 no.3
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• pp.477-483
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• 2015

This study deals with the decision problem of sample size by the relative standard error of estimates derived from survey results in successive occasions. The population of the construction in business survey results is used to calculate quartile of the relative standard error of the 1,000 sample obtained from simple or stratified random sampling. The sample size at time t with a relative standard error of the point (t-1) in the successive occasions were calculated according to the sampling method. As a result, in terms of the sample size according to the size of the relative standard error of the (t-1), simple random sampling differs significantly from stratified sampling. In addition, we could see differences in sample size (depending on how the population is stratified) and that careful attention is required in the problem of sample size by the relative standard error of estimates derived from survey results in successive occasions.

• Korean Journal of Applied Biomechanics
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• v.15 no.1
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• pp.1-18
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• 2005

The purpose of this study was to evaluate performance characteristics. in the success of team attack during volleyball competition. For this, real game was analyzed using S-VHS video camera for three dimensional cinematography. The contents of this research were receive to set time, set to spike time, setter moving distance, ball position during set and attacker's relative ball position during jump and spike, and open area at spike. Among the various kinematical factors considered in this study, the ball height relative spiker and open area were found to be related to offensive performance. This finding implies that although their direct impact were not significant the other factors could have indirect impact on offensive performance by increasing open area. Thus, receiver, setter, assistant attacker, and main attacker should practice for successful performance in each stage. Lastly, it is necessary to develop kinematic variables to evaluate performance characteristics of players. Further study may consider the best defense position against the attack of the opponent player.

• Journal of Biosystems Engineering
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• v.5 no.1
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• pp.15-23
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• 1980

Natural-air drying systems have been extensively used for cereal grains, and many researches on the systems have been conducted in foreign countries. However, little research on drying rough rice with natural air has been done. Especially . little research on natural air drying of rough rice based on weather data has been done in Korean. The objective of this study was to present fundamental data for estimating optimum requirements and basic information available for natural air drying of rough rice based on the weather data . The weather data analyzed in this study were the 10-year (1969 to 1978) record of air temperatures, wet-bulb temperatures and relative humidities, which were three-hourly observations in Taegu area. The results of this study are summarized as follows ; 1 From the results of weather data analysis the average air temperature was about $14.8^\circ$and the average relative humidty 67.5% . Average equilibrium moisture content appeared to be 13.8 percent on wet basis, which showed great potential for natural air drying in Taegue area in October. 2. Possible fan operation time based on the equilibrium moisture content of 15% on wet basis was about 14 hours a day during October in Taegu area. Probabilities of possible drying days based on minimum time available for drying in a day were analyzed. 3. Minimum air flow requirements based on the worst year were determined for different fan operation methods and initial moisture contents.

• Journal of Korean Institute of Industrial Engineers
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• v.30 no.1
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• pp.44-49
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• 2004

The aim of this study is to compare the methods in analyzing bio-signals representing measure driver's psychophysiological staus. This study has considered three approaches: first, the deterministic approach calculating the mean and standard deviation of bio-signal, second, probabilistic approach converting driver's bio-signal values to probability density function and identifying individual state relative to overall distribution, and third, diagnostic approach identifying the pattern change of signal over certain period of time. For evaluation of analysis methods, driver's bio-signal was collected under various road conditions, and three analysis approaches were applied respectively. In result, the deterministic approach was found to be simple to use, but generated a large variability of bio-signal. The probabilistic approach provide a relative status of individual driver among overall population, but too much affected by temporal variability of individual driver. The diagnostic approach seemed to reasonably find driver's psychophysiological change over certain period of time, but still needs to develop quantification method of the bio-signal.

• Proceedings of the Korean Institute of Interior Design Conference
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• 1999.04a
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• pp.102-105
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• 1999

The purpose of this study is to analyze the meanings and expressional characteristics of space-time concept in modern architecture. As the architecture spaces reflect and represent the characteristics of times, the meaning and modern expression of space-time concept was studied in the developmental process of space concept on the base of the background of philosophy, science and psychology. At the late 19th century, space concept was changed with relative time-space in philosophy and science and the theory of visual perception. In the beginning of 20th century, space-time concept that combined space with time in the process of image open space expanded movement was developed. In modern architecture, it was expressed as the freedom of movement by open space expanded infinitely and/or abstract space without spacial measure, multiple view point by superimposed and/or polyhedric space and kinetic vision by dynamic and/or continuous space.

• Journal of the Korean Dietetic Association
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• v.2 no.1
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• pp.29-37
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• 1996

This study was undertaken to evaluate the relation between obesity and dietary life of children aged 4-7 divided into two groups based on height for age, weight for age and weight for height. Controls were selected based on sex and age similar with those of cases. Cases and controls were selected using the combination of weight for height, weight for age and height for age by the World Health Organization standard. Cases were 23 children judged as obese. Controls were 37 judged as normal. Whether their mother had a job or not, showed relative risk 1.35(95% C1 0.32-5.64). In obese group, employmental statue of mother was 17.4% compared with 13.5% in control group. In mother's concern for cooking pattern, the relative risk was 5.64 and 95% CI was 1.70-18.66 in the item of "We consider the color arrangement when we serve foods" which was the highest rate. The item having the lowest relative risk was "We cook the meal by ourselves with spending time" which of the relative risk was 0.52 and 95% CI was 0.16-1.65. The item having a great significance in the dietary habit of subjects were "They beat the tablewear with the chopstick"(RR:1.64, 95% CI:0.22-12.73) and "I talk with food in my mouth"(RR :1.11, 95% CI:0.39-3.15), and the other items didn't show significancy. Number of food eating per day for male was 30.0$\pm$10.93 in obese group where as 23.2$\pm$9.80 in control group. 22.3$\pm$4.56, 21.8$\pm$10.91 were taken obese group and control group respectively in female. In the survey for general habit in life, the item of "We has a time for conversation with our family regularly" was high correlation to obesity and item of "We made our children change clothes and go to toilet themselvesj has slight relation to obesity. From above, we observed normal and obese children had different factors such as mother's attitude for preparing meals, table manners and habit of living. So we should take a continuous interest in children's dietary life in order to correct the wrong dietary habit and to protect from future problems.

• Journal of Korean Academy of Nursing Administration
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• v.9 no.2
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• pp.205-216
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• 2003

Purpose : This study wad aimed to estimate nursing cost for hemodialysis of secondary hospitals using Resource Based Relative Value Scale(RVRBS). Method : The first, calculated nursing workload for the hemodialysis of secondary hospitals. Second, measured each spent time according to 14 nursing behaviors. Third, computed Resource Based Relative Value(RBRV) scores and nursing expenses of hemodialysis nurse. Finally, estimated nursing cost for hemodialysis of secondary hospitals, Result & Conclusion : The mean RBRV scores for each nursing behaviors were from 218.9 to 383.9 point(mean=312.7). The high RBRV socres were 383.9(Complication during hemodialysis), 353.7(Access patient vascular), 345.7 (Patient Teaching). Nursing cost for hemodialysis was estimated 23,234(won).