• Journal of Korean Port Research
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• v.10 no.2
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• pp.91-101
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• 1996

Today transportation problems are severer with the increase of the vehicles and travel demand in urban areas, but could not be completely solved with only the expansion of the new transportation facilities. Because the expansion of the new transportation facilities are limited in urban areas. As one of the Transportation System Management(TSM) techniques in this study, the simulation results of the existing signal systems which were operated based upon the peak time periods for increasing the efficiency on the pretimed signalized intersections(PSI) during the different time periods : the AM on-Peak, the AM off-Peak, the PM off-Peak, and the PM on-Peak, were as follows : i) There was no distinct difference in the total traffic volumes concentrated on the signalized intersections during the different time periods, but a considerably big difference in the directional traffic volumes for those time periods. ii) There were about 53% reduction of the average delay and 51% reduction of the fuel consumption when applying the different signal systems to the different time periods regardless of the CBD and Non-CBD. iii) There were about 36% increase of the average delay and 33% increase of the fuel consumption when applying the same signal systems during the peak time periods to the different time periods regardless of the CBD and Non-CBD. Based on the above results, it was concluded that constructing the different signal systems for the different time periods would be better than construction the same ones for those periods on the pretimed signalized intersections in urban areas.

• Journal of Ecology and Environment
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• v.34 no.2
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• pp.193-202
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• 2011

We studied temperature sensitivity characteristics of soil respiration during periods of rising and falling temperatures within a common temperature range. We measured soil respiration continuously through two periods (a period of falling temperature, from August 7, 2003 to October 13, 2003; and a period of rising temperature from May 2, 2004 to July 2, 2004) using an open-top chamber technique. A clear exponential relationship was observed between soil temperature and soil respiration rate during both periods. However, the effects of soil water content were not significant, because the humid monsoon climate prevented soil drought, which would otherwise have limited soil respiration. We analyzed temperature sensitivity using the $Q_{10}$ value and $R_{ref}$ (reference respiration at the average temperature for the observation period) and found that these values tended to be higher during the period of rising temperature than during the period of falling temperature. In the absence of an effect on soil water content, several other factors could explain this phenomenon. Here, we discuss the factors that control temperature sensitivity of soil respiration during periods of rising and falling temperature, such as root respiration, root growth, root exudates, and litter supply. We also discuss how the contribution of these factors may vary due to different growth states or due to the effects of the previous season, despite a similar temperature range.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.1
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• pp.184-190
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• 2005

The aim of this study is to find out what inhibition effects the Germinated Seed of Rhynchosia Volubilis(GSRV) has by its feeding period on the bone absorption in ovariectomized white rats. Close examination of the amounts of the Cathepsin-K in the rats by the groups of one, two and three-day germination periods led to the following conclusions. Feeding non-ovariectomized white rats with GSRV by the groups of one, two and three-day germination periods showed less amounts of Cathepsin-K in their proximal tibia in all the feeding periods of two, three and four weeks than in the case of control group, revealing a statistical significance. Feeding ovariectomized white rats with GSRV by the groups of one, two and three-day germination periods showed less amounts of Cathepsin-K in their proximal tibia in all the feeding periods of two, three and four weeks than in the case of the control group, revealing a statistical significance. Therefore, the Germinated Seed of Rhynchosia Volubilis(GSRV) is believed to have inhibition effects on bone resorption.

• Korean Journal of Microbiology
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• v.17 no.2
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• pp.81-93
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• 1979

The mycelium of Rhizopus nigricans was harvested at intervals during the sporulation periods, fractioned into various cell components and analyzed the con!eiits of various cell materials in order to clarify the optimum conditions of sporulation and some characteristics of the metabolism during tke sporulation periods. The changes in enzyme activities, such as amylase and protease, were also measured during the sporulation period,. 1. Mycelium in distilled water culture, as control, did not sporulate but mycelial mat cultured in Petridish without mutrient spourulated. Optimum temperature range for sporulation was $20{\sim}25^{\circ}C$. 2. During the sporulation and maturation periods, proteins, especially alkali-labile protein were decreased remarkably but free amino acid and ninhydrin reactive substances in acid soluble fraction were increased, compared with control. 3. Acid solable polyphosphate was decreased but acid insoluble polyphosphate was increased, during the sporulation. 4. Carbohydrate and hexosamine in acid soluble fraction were increased, while carbohydrate in alkali insoluble residual fraction was decreased during the sporulation periods. 5. Amounts of UV-absorbing material in deoxyribonucleic acid fraction was increased a little but those in ribonucleic acid fraction was decreased, compared with control. 6. Intracellular amylases and proteases activities insporulating mycelial mat were increased continuously during the sporulation and maturation periods.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.2
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• pp.179-192
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• 2001

In order to characterize the distribution patterns of PAHs between Yellow Sand (YS) and non-Yellow Sand(NYS) periods, we collected and analyzed aerosol samples for PAHs for the periods covering 28 March through 24 April 2000. The concentrations of TSP measured during the YS periods were approximately two times higher than the NYS periods. By contrast, the concentrations of PAHs during YS were higher than those of NYS by 140%. In ad-dition, their concentrations in PM 10 were larger than those TSP by 120% . Detailed inspections of our data indi-catd that three species including chrysene. benzo(b)fluoranthene, and benzo(k)fluoranthene were effeciently ad-sorbed by particles less than 10${\mu}{\textrm}{m}$ diameter and that there were dominating the distribution characterstics of PAHs during the YS periods. Results of correlation analysis also indicated that PAHs exhibited strong correlations with those pollutants originating from combustion sources. It is thus concluded that pollutants such as toxic PAHs that originate from diverse anthropogenic sources of China should be contributing to the degradation of the ambient air quality in Seoul.

• Earthquakes and Structures
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• v.19 no.2
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• pp.119-128
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• 2020

In seismic design of a pylon supporting transmission lines in an overhead electricity transmission system, an estimation of the fundamental periods of the pylon in two orthogonal vertical planes is necessary to compute the seismic forces required for sizing pylon members and checking pylon deflections. In current practice, the fundamental periods of a pylon in two orthogonal vertical planes are typically obtained from eigenvalue analyses of a model consisting of the pylon of interest as well as some adjacent pylons and the transmission lines supported by these pylons. Such an approach is onerous and numerically inconvenient. This research focused on development of a simplified method to determine the fundamental periods of pylons. The simplified method is rooted in Rayleigh's quotient and is based on a single-pylon model. The force vectors that can be used to generate the shape vectors required in Rayleigh's quotient are presented in detail. Taking three pylons selected from representative overhead electricity transmission systems having different design parameters as examples, the fundamental periods of the chosen pylons predicted from the simplified method were compared with those from the rigorous eigenvalue analyses. Result comparisons show that the simplified method provides reasonable predictions and it can be used as a convenient surrogate for the tedious approach currently adopted.

• Magazine of the Korean Society of Agricultural Engineers
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• v.17 no.3
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• pp.3848-3859
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• 1975

The author attempted to find most suitable formulas for probable rainfall intensities with analysis and consideration for characteristics of rainfall intensities according to the short and long period return periods at Cheong-Joo district. Above mentioned formulas induced by this study can be contributed to the credibility of runoff estimation for urban sewerage system, drainage works in small catchment area and embankment works in the rivers. The results of this study are summarized as follows: 1 Calculation values by Gumbel-Chow method were selected as a mean values for the calculation of probable rainfall intensities according to return periods in the short period. 2. Calculations for probable rainfall intensities for long period are based upon to the result by Iwai's method. Talbot type, {{{{I= {a} over {t+b} }}}} is confirmed as a most suitable formula for probable rainfall intensities among calculation methods in the short periods at Cheong-Joo district. 4. Specific coefficient method, I24=RN24${\beta}$N was selected as a means of calculation for suitable formulas of probable rainfall intensities according to return periods in case of long period. 5. Runoff estimation with high credibility by rational formula can be anticipated by establishment for the most suitable probable rainfall intensities at Cheong-Joo district.

• The Korean Journal of Food And Nutrition
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• v.5 no.2
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• pp.123-131
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• 1992

This study was designed to find out the effects of aerobic exercise on the serum lipids in the middle-aged women. The effects of aerobic dancing on serum total cholesterol(TC), triglyceride(TG) and HDL-cholesterol (HDL-C) were studied in eight sedentary women(control group) and twenty seven aerobic exercising women(aerobic group) , aged 35∼45%. Aerobic exercising subjects were divided into 3 group; 2 to 3 months exercising group(Al), 4 to 10 months exercising group(AH), over 1 year exercising group(AIII) according to the periods of exercise. The serum lipid levels of aerobic exercising groups(AI, AII, AIIII) were compared with those of control group. The results statistically analyzed were summarized as follows : 1) The serum TG levels of aerobic groups decreased very significantly compared with those of control group(p< 0.001) and tended to be lower with the increase in aerobic periods. But there were no significant differences among aerobic groups by ANOVA. 2) The serum TC levels of aerobic groups decreased compared with those of control group and tended to be lower with the increase of aerobic periods. But there were no significant differences among groups. 3) Serum HDL-cholestrol level of A I group was elevated significantly compared with that of control group and significant difference was observed according to the aerobic periods : AR group exhibited higher serum HDL-cholesterol values than AH group, and AH group higher than A I group.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.7
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• pp.605-608
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• 2011

In this study, OSA (the obstructive sleep apnea) periods were detected in patients with OSA during sleep because of the treatment was different according to the frequency and symptoms of obstructive sleep apnea. ANS (autonomic nervous activity) was changed by obstructive sleep apnea periods so we intended to detect the periods to care the obstructive sleep apnea patients. RR intervals, SDNN (standard deviation of normal to normal) and RMSSD (root mean square standard deviation) were calculated in time domain analysis and LF (low frequency), HF (high frequency), NHF (normalized high frequency), NLF (normalized low frequency) were calculated in frequency domain analysis of HRV (heart rate variability) with obstructive sleep apnea patients. In this paper, SDNN (standard deviation of normal to normal) of time domain analysis were decreased in the obstructive sleep apnea periods. And NLF and LF/HF ratio were increased and NHF (normalized high frequency) was decreased in the frequency domain analysis. The parameters can be used to treat obstructive sleep apnea patients by detecting the obstructive sleep apnea periods such as CPAP (continuous positive airway pressure).

• Korean Journal of Veterinary Research
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• v.54 no.1
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• pp.13-19
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• 2014

Animal bones excavated with earthenware from the shell mound at the Jeju Jongdali 1819 archeological site, where three consecutive chronological layers covering the Neolithic (B.C. 15C-B.C. 10C), early Tamra, and late Tamra periods have been identified, were morphologically classified. The majority of the bones from all three periods were broken or split. The major fauna of the mammalian bones in all periods were Cervus spp., Sus scrofa, and Bos taurus. In the early and late Tamra periods, bones of small animals including Mustela sibirica coreana, Meles meles, Rodentia, and Aves were also found in small number. The excavated bones were from all parts of the animal bodies, including head, trunk, forelimb, and hindlimb. Collectively, these findings suggest that the major fauna from the Neolithic to late Tamra periods consisted of Cervus spp., Sus scrofa, and Bos taurus and that the fauna was dissected and carried to the shell mound site after hunting. Information from the bone remains in the shell mound are useful data for study of the wildlife and domestic animals living during the prehistoric period of Jeju Island.