• The Korean Journal of Applied Statistics
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• v.28 no.3
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• pp.529-540
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• 2015

A cross-over design is frequently used in clinical trials (especially in bioequivalence tests with a parametric method) for the comparison of two treatments. Missing values frequently take place in cross-over designs in the second period. Usually, subjects that have missing values are removed and analyzed. However, it can be unsuitable in clinical trials with a small sample size. In this paper, we compare single imputation methods in a $2{\times}2$ cross-over design when missing values exist in the second period. Additionally, parametric and nonparametric methods are compared after applying single imputation methods. A Monte-Carlo simulation study compares type I error and the power of methods.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.7C
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• pp.743-754
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• 2006

In the proposed method, two regular laser working at two different wavelengths perform moving object detection alternatively in time. The laser intensity and the beaming period of each laser is equally maintain as to the single laser radar, hence, externally, dual beam lasers radar works exactly same as the single beam laser radar except that the proposed dual lasers radar needs additional post-processing of received signals in the receiver. To verify the robustness of the proposed method, a set of computer simulation has been performed. The communication channel is assumed to be additive white Gaussian noise, and the perfect synchronization is assumed. All other simulation parameters such as signal power and signalling period are equally maintain in both systems while the signal processing time such as spreading and filtering are expected to be trivial in call cases.

• Journal of Communications and Networks
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• v.14 no.4
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• pp.434-442
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• 2012

Several gateway selection schemes have been proposed that select gateway nodes based on a single Quality of Service (QoS) path parameter, for instance path availability period, link capacity or end-to-end delay, etc. or on multiple non-QoS parameters, for instance the combination of gateway node speed, residual energy, and number of hops, for Mobile Ad hoc NETworks (MANETs). Each scheme just focuses on the ment of improve only a single network performance, i.e., network throughput, packet delivery ratio, end-to-end delay, or packet drop ratio. However, none of these schemes improves the overall network performance because they focus on a single QoS path parameter or on set of non-QoS parameters. To improve the overall network performance, it is necessary to select a gateway with stable path, a path with themaximum residual load capacity and the minimum latency. In this paper, we propose a gateway selection scheme that considers multiple QoS path parameters such as path availability period, available capacity and latency, to select a potential gateway node. We improve the path availability computation accuracy, we introduce a feedback system to updated path dynamics to the traffic source node and we propose an efficient method to propagate QoS parameters in our scheme. Computer simulations show that our gateway selection scheme improves throughput and packet delivery ratio with less per node energy consumption. It also improves the end-to-end delay compared to single QoS path parameter gateway selection schemes. In addition, we simulate the proposed scheme by considering weighting factors to gateway selection parameters and results show that the weighting factors improve the throughput and end-to-end delay compared to the conventional schemes.

• Toxicological Research
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• v.20 no.3
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• pp.281-292
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• 2004

The purpose of this study was to assess the single and 5 week oral dose toxicity of calcitriol and alendronate combination (1 : 10,000) treatment for osteoporosis or Paget's disease in male and female rats. In single dose oral toxicity study, the values of $LD_{50}$ of calcitriol and alendronate mixture were 750.075 mg/kg in male rats and 775.0775 mg/kg in female rats, respectively. Body weight and food consumption were continuously increased after adminstration of calcitriol and alendronate mixtures, and there was no significant changes in body weight and food consumption in all groups. In five-week oral toxicity study of calcitriol and alendronate mixture at a dose of 0.2 $\mu\textrm{g}$ + 2 mg, 1 $\mu\textrm{g}$ + 10 mg, 5 $\mu\textrm{g}$ + 50 mg and 25 $\mu\textrm{g}$ + 250 mg, respectively, there was no mortality, abnormal behavior and appearance in all groups throughout the administration period (5 weeks) and recovery period (2 weeks). Dose-dependent changes in parameters of urinalysis and hematological analysis were not observed in male and female rats treated with calcitriol and alendronate mixtures. All the values of the parameters appeared to be in the normal range. These data indicate that both calcitriol and alendronate are drugs having low toxicity in rats. NOAEL of calcitriol and alendronate mixtures were 50.005 mg/kg in 5-week oral toxicity.

• Journal of Pharmacopuncture
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• v.18 no.3
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• pp.42-48
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• 2015

Objectives: The aim of the study is to investigate both the single-dose intramuscular injection toxicity and the approximate lethal dose of water-soluble Carthami-flos and Cervi cornu parvum pharmacopuncture (WCFC) in male and female Sprague-Dawley (SD) rats. Methods: The study was conducted at Biotoxtech Co. according to the Good Laboratory Practice (GLP) regulation and the toxicity test guidelines of the Ministry of Food and Drug Safety (MFDS) after approval of the Institutional Animal Care and Use Committee. Dosages for the control, high dose, middle dose and low dose groups were 0.5 mL/animal of saline and 0.5, 0.25 and 0.125 mL/animal of WCFC, respectively. WCFC was injected into the muscle of the left femoral region by using a disposable syringe (1 mL, 26 gauge). The general symptoms and mortality were observed 30 minutes, 1, 2, 4, and 6 hours after the first injection and then daily for 14 days after the injection. The body weights of the SD rats were measured on the day of the injection (before injection) and on the third, seventh, and fourteenth days after the injection. Serum biochemical and hematologic tests, necropsy examinations, and histopathologic examinations at the injection site were performed after the observation period. Results: No deaths, abnormal clinical symptoms, or significant weight changes were observed in either male or female SD rats in the control or the test (0.125, 0.25, and 0.5 mL/animal) groups during the observation period. No significant differences in hematology and serum biochemistry and no macroscopic abnormalities at necropsy were found. No abnormal reactions at injection sites were noted on the topical tolerance tests. Conclusion: The results of this single-dose toxicity study show that WCFC is safe, its lethal doses in male and female SD rats being estimated to be higher than 0.5 mL/animal.

• Journal of Korean Medicine Rehabilitation
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• v.25 no.2
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• pp.73-80
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• 2015

Objectives To assess the safety of Shinbaro3 Pharmacopuncture by analyzing the potential single-dose intramuscular toxicity of Shinbaro3 Pharmacopuncture at various dose levels in SD (Spraque-Dawley) rats and Beagle dogs. Methods For evaluation of single-dose intramuscular toxicity of Shinbaro3 Pharmacopuncture, 40 SD rats (20 male and 20 famale) and 4 Beagle dogs (2 male and 2 female) were used. The rats were divided in four groups of 10 each, and treated intramuscularly with Shinbaro3 Pharmacopuncture at doses of 0.3, 0.6 and 1.2 mg/kg in distilled water, and distilled water as a vehicle control group, respectively. The Beagle dogs were divided into two groups of 2 each, and treated intramuscularly with Shinbaro3 Pharmacopuncture at doses of 0.15, and 0.3 mg/kg in distilled water, respectively, and signs of toxicity were observed. After a wash-out period of 3 days, the procedure was repeated with Shinbaro3 Pharmacopuncture at doses of 0.6, and 1.2 mg/kg in distilled water, respectively. Mortality, body weight changes, and necropsy findings were examined during the study period. Results There were no mortalities in either the SD rats or Beagle dogs. There were also no significant differences in adverse effects, body weight, or necropsy findings between the Shinbaro3 Pharmacopuncture and control groups. Conclusions There results suggest that the lethal dose 50 ($LD_{50}$) and approximate lethal dose (ALD) value of the test substance Shinbaro3 Pharmacopuncture are higher than 1.2 mg/kg in SD rats and Beagle dogs.

• Korea journal of population studies
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• v.6 no.1
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• pp.3-42
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• 1983

The purposes of this paper is to introduce a technique for construction of nuptiality tables using proportion single of synthetic cohorts between times at two consecutive censuses, and to observe patterns of change in marriage habit of Korean through the nuptiality tables for single population from 1925 to 1980. In this paper abridged gross and net nuptiality tables for single population of Korea have been constructed for the four quinquinial period: 1925-1930, 1955-1960, 1970-1975, and 1975-1980. Significant time trend has been observed in the nuptiality rates among the single population. The major findings observed in each table are as follows; (1)During 1925-1930, the rates are initially small, but increase rapidly until they reach a maximum at ages 25-29 for bachelors and 20-24 for spinsters, following which they are still in high level. (2)During 1955-1960, the age pattern of nuptiality begins to change; for female population, the rates increase rapidly in the same pattern as in l925-l930 untill they reach the highest level at ages 25-29, after which they gradually decline. During the period, however, there were an unprecedented high level of marriage rates for male population at a relatively later ages. (3)During 1970-1975, Korea had experienced a transition in marriage habits; at this times, nuptiality rates for both sexes showed the same pyramid shaped patterns as in western countries as age increases. The mean ages at marriage for both sexes also reached the highest level of 27.5 years for males and 24.1 years for females. (4)During 1975-1980, the age patterns of nuptiality showed almost the same patterns as in 1970-1975. In the later age group, however, age-specific marriage rates for both sexes greatly declined compared to the level of 1970-1975, while the rate in age group of 20-24 for male population greatly increased.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.65-66
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• 2021

Glycyrrhiza species (Licorice) are one of the most commonly used medicinal plants in Asian countries such as China, India and Korea. It has been traditionally used to treat many disease including cough, cold, asthma, fatigue, gastritis and respiratory tract infections. Glycyrrhiza new variety, Wongam (WG), have been developed by Korea Rural Development Administration and revealed several pharmacological effects. However, limited data are available on the potential adverse effects of the WG. Here, we evaluated the general toxicity of the WG extract through single oral dose toxicity study in Sprague-Dawley rats. After single oral dose administration, there was no mortality up to 5000 mg/kg during experiment period. In addition, there was no clinical signs including body weight change, gross findings and necropsy findings up to 5000 mg/kg during experiment period. To conclude, the no-observed-adverse-effect level (NOAEL) of WG was higher than 5000 mg/kg and no target organs were identified in male and female Sprague-Dawley rats.

• Membrane and Water Treatment
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• v.11 no.1
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• pp.79-85
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• 2020

A single-stage deammonification with a sequencing batch reactor (SBR) that simultaneous nitritation, anaerobic ammonia oxidation (anammox), and denitrification (SNAD) occur in one reactor has been widely applied for sidestream of wastewater treatment plant. For the stable and well-balanced SNAD, a feeding strategy of influent wastewater is one of the most important operating factors in the single-stage deammonification SBR. In this study, single-stage deammonification SBR (working volume 30L) was operated to treat a high-strength ammonium wastewater (1200 mg NH₄⁺-N/L) with different feeding strategies (single feeding and nine-step feeding) under the condition without COD. Each cycle of the step feeding involved 6 sub-cycles consisted of aerobic and anoxic periods for partial nitritation (PN) and anammox, respectively. Contrary to unstable performance in the single feeding, the step feeding showed better deammonification performance (0.565 kg-N/m³/day). Under the condition with COD, however, the nitrogen removal rate (NRR) decreased to 0.403 kg-N/m³/day when the Nine-step feeding strategies had an additional denitrification period before sub-cycles for PN and anammox. The NRR was recovered to 0.518 kg-N/m³/day by introducing an enhanced multiple-step feeding strategy. The strategy had 50 cycles consisted of feed, denitrification, PN, and anammox, instead of repeated sub-cycles for PN and anammox. The multiple-step feeding strategy without sub-cycle showed the most stable and excellent deammonification performance: high nitrogen removal efficiency (98.6%), COD removal rate (0.131 kg-COD/m³/day), and COD removal efficiency (78.8%). This seemed to be caused by that the elimination of the sub-cycles might reduce COD oxidation during aerobic condition but increase the COD utilization for denitrification period. In addition, among various sensor values, the ORP pattern appeared to be applicable to monitor and control each reaction step for deammonification in the multiple-step feeding strategy without sub-cycle. Further study to optimize the number of multiple-step feeding is still needed but these results show that the multiple-step feeding strategy can contribute to a well-balanced SNAD for deammonification when treating high-strength ammonium wastewater with COD in the single-stage deammonification SBR.

• Journal of Korean Society of Transportation
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• v.17 no.4
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• pp.47-58
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• 1999

The Purpose of this Paper is to develop a multi-period bus scheduling model, in which a decomposition technique is applied. In general a bus scheduling requires a vast amount of calculation. Thus, a bus scheduling is a very complicated problem even with a single depot and is almost unable to obtain the optimal solution theoretically with many depots. In this paper in order to simplify the problem, the whole operating hours of a day are partitioned into several time periods. In one period, the same headways are maintained. For one period, the bus scheduling is simple and the solution applying the FIFO(First-In, First-Out) Principle is the optimal. However, connection between Periods remains as another scheduling Problem with a reduced problem size. This paper suggests how to connect bus schedules of consecutive periods efficiently, minimizing the operating cost. Through case studies for multiple routes with a single depot, this decomposition technique is proved to be effective practically.