• Title/Summary/Keyword: Time intervals

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Transient Linear Elastodynamic Analysis by the Finite Element Method (유한요소법을 이용한 과도 선형 동탄성 해석)

  • Hwang, Eun-Ha;Oh, Guen
    • Journal of the Korean Society of Industry Convergence
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    • v.12 no.3
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    • pp.149-155
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    • 2009
  • A new finite element equation is derived by applying quadratic and cubic time integration scheme to the variational formulation in time-integral for the analysis of the transient elastodynamic problems to increase the numerical accuracy and stability. Emphasis is focused on methodology for cubic time integration scheme procedure which are never presented before. In this semidiscrete approximations of the field variables, the time axis is divided equally and quadratic and cubic time variation is assumed in those intervals, and space is approximated by the usual finite element discretization technique. It is found that unconditionally stable numerical results are obtained in case of the cubic time variation. Some numerical examples are given to show the versatility of the presented formulation.

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Proper Numerical Scheme to Solve the Flow Past a Circular Cylinder with Time and Grid Size Variations (시간과 격자 크기 변화에 따른 원주후류해석의 경제적 수치기법)

  • Maeng, Joo-Sung;Kim, Yong-Dae;Choi, IL-Kon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.5
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    • pp.652-659
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    • 2000
  • The purpose of this study is to present the most effective numerical scheme to calculate the unsteady flows. In order to calculate the flow quantities of flow past a circular cylinder, Three-time level and five convective schemes are applied to unsteady and convective terms, respectively. The values obtained are compared with those from the existing experimental and numerical studies. At Reynolds numbers up to 160, time intervals can be expanded 10 times of Implicit Euler scheme using Three-time level method, and it is found that QUICK and CUI schemes work much stable than others even if less grid density conditions. The combination of Three-time level and QUICK scheme gives high resolutions for laminar unsteady problems with PC level.

A Path Travel Time Estimation Study on Expressways using TCS Link Travel Times (TCS 링크통행시간을 이용한 고속도로 경로통행시간 추정)

  • Lee, Hyeon-Seok;Jeon, Gyeong-Su
    • Journal of Korean Society of Transportation
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    • v.27 no.5
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    • pp.209-221
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    • 2009
  • Travel time estimation under given traffic conditions is important for providing drivers with travel time prediction information. But the present expressway travel time estimation process cannot calculate a reliable travel time. The objective of this study is to estimate the path travel time spent in a through lane between origin tollgates and destination tollgates on an expressway as a prerequisite result to offer reliable prediction information. Useful and abundant toll collection system (TCS) data were used. When estimating the path travel time, the path travel time is estimated combining the link travel time obtained through a preprocessing process. In the case of a lack of TCS data, the TCS travel time for previous intervals is referenced using the linear interpolation method after analyzing the increase pattern for the travel time. When the TCS data are absent over a long-term period, the dynamic travel time using the VDS time space diagram is estimated. The travel time estimated by the model proposed can be validated statistically when compared to the travel time obtained from vehicles traveling the path directly. The results show that the proposed model can be utilized for estimating a reliable travel time for a long-distance path in which there are a variaty of travel times from the same departure time, the intervals are large and the change in the representative travel time is irregular for a short period.

Bioequivalence Assessment of DM Tablet to Motilium-$M^{(R)}$ Tablet (모티리움엠정(말레인산 돔페리돈 12.72 mg)에 대한 디엠정의 생물학적동등성 평가)

  • Cho, Seong-Wan;Kim, Young-Il;Lee, Jong-Oh;Bang, Joon-Seok;Jeong, Ji-Hoon
    • Korean Journal of Clinical Pharmacy
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    • v.18 no.2
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    • pp.106-113
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    • 2008
  • The aim of this study was to evaluate the bioequivalence of two domperidone preparations. Bioequivalence assessment was conducted on 34 healthy volunteers who received two tablets (Domperidone Maleate, 12.72 mg/tablet) in the fasting state, in a randomized balanced $2{\times}2$ cross-over study design. This whole study was performed according to the implementation guidelines of the Korea Food Drug Administration. After dosing of two tablets, blood samples were collected serially for a period of 36 hours. Plasma was analyzed for domperidone by using LC/MS/MS assay method. The analysis system was validated in specificity, accuracy, precision, and linearity. $AUC_t$, (the area under the plasma concentration-time curve from the zero-time to 36 hr) was calculated through the trapezoidal rule. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma domperidone concentration-time data of each volunteer. No significant sequence effect was found for the bioavailability parameters indicating that the cross-over design was properly performed. The 90%-Confidence intervals of the $AUC_t$ ratio and the $C_{max}$ were from log 0.8007 to log 1.1240 and log 0.8645- log 1.2483, respectively. These values were within the acceptable bioequivalence intervals between 0.80 and 1.25. Therefore, this study demonstrated that two formulations have bioequivalence with respect to the rate and extent of absorption.

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Bioequivalence of Topamin Tablet to Topamax Tablet (Topiramate 100 mg) (토파맥스 정(토피라메이트 100mg)에 대한 토파민 정의 생물학적동등성)

  • Seo, Ji-Hyung;Lee, Myung-Jae;Choi, Sang-Jun;Kang, Jong-Min;Lee, Jin-Sung;Tak, Sung-Kwon;Lee, Kyung-Tae
    • Journal of Pharmaceutical Investigation
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    • v.38 no.4
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    • pp.277-282
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    • 2008
  • The purpose of the present study was to evaluate the bioequivalence of two topiramate tablets, Topamax tablet (Janssen Korea. Co., Ltd., Seoul, Korea, reference drug) and Topamin tablet (Myungmoon Pharm. Co., Ltd., Seoul, Korea, test drug), according to the guidelines of Korea Food and Drug Administration (KFDA). Twenty-four healthy male Korean volunteers received one tablet at the dose of 100 mg topiramate in a $2{\times}2$ crossover study. There were two-weeks washout period between the doses. Plasma concentrations of topiramate were monitored by an LC-MS/MS for over a period of 96 hr after administration. $AUC_t$ (the area under the plasma concentration-time curve from time zero to 96 hr) was calculated by the linear trapezoidal rule method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. Analysis of variance (ANOVA) was carried out using logarithmically transformed $AUC_t$ and $C_{max}$. The 90% confidence intervals of the $AUC_t$, ratio and the $C_{max}$ ratio for Topamin/Topamax were $\log0.88{\sim}\log1.02$ and $\log0.87{\sim}\log1.03$, respectively. These values were within the acceptable bioequivalence intervals of $\log0.80{\sim}\log1.25$. Taken together, our study demonstrated the bioequivalence of Topamax and Topamin with respect to the rate and extent of absorption.

A Clinical Study of Collaboration between Western and Korean Medicine for the Treatment of Peripheral Facial Palsy in a Korean Medicine Hospital

  • Kim, Jaewon;Kim, Yongsuk
    • Journal of Acupuncture Research
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    • v.37 no.3
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    • pp.161-166
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    • 2020
  • Background: The purpose of this study was to investigate the characteristics and direction of treatment for peripheral facial palsy (PFP) based on medical collaboration between Western and Korean medicine departments. Methods: There were 195 outpatients with PFP identified retrospectively by examining electronic medical records. These patients were treated with Korean and Western medicine from January 1st, 2018 to December 31st, 2018 at the Kyung Hee University hospital. Records were analyzed according to the patients' demographic characteristics and clinical features of the collaborative combined treatment. Results: According to the collaborative treatment pathway, the number of patients consulted from Western medicine departments was more than consulted from Korean department for the first time. The time taken by the Western medicine departments to consult with the patients at the Korean center for the first time was 14.9 days from the onset of symptoms. Acupuncture was the most frequently used Korean medicine treatment. The total treatment period for Korean medicine sessions and intervals were 91.9 days, 23 times and 3.6 days, respectively. When the Korean medicine center consulted with Western medicine departments, the time taken until the first consultation was 8.5 days from the onset of symptoms. Medication was the most used treatment, prescribed after 3.1 days. The most frequently used clinical test was an electromyogram, and this was performed after 20.5 days. The total treatment period, sessions and intervals were 21.2 days, 2.8 times and 5 days, respectively. Conclusion: The clinical status of collaborative treatment for PFP was determined including the timing and interval of consultation according to treatments.

Bioequivalence of Mepiril Tablet to Amaryl Tablet (Glimepiride 2 mg) by Liquid Chromatography/Electrospray Tandem Mass Spectrometry

  • Lee, Heon-Woo;Cho, Sung-Hee;Park, Wan-Su;Im, Ho-Taek;Rew, Jae-Hwan;Lee, Kyung-Tae
    • Journal of Pharmaceutical Investigation
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    • v.35 no.4
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    • pp.287-293
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    • 2005
  • The purpose of the present study was to evaluate the bioequivalence of two glimepiride tablets, Amaryl tablet (Handok & Aventis Korea, reference drug) and Mepiril tablet (Myungmoon Pharm. Co., Ltd., Korea, test drug), according to the guidelines of Korea Food and Drug Administration (KFDA). After adding an internal standard (glibenclamide) to human plasma, plasma samples were extracted using 1mL of methyl tertiary butyl ether. Compounds extracted were analyzed by reverse-phase HPLC with multiple reaction monitoring (MRM) mode analyte detection. This method for determination glimepiride proved accurate and reproducible, with a limit of quantitation of 2 ng/mL in human plasma. Twenty-four healthy male Korean volunteers received each medicine at the glimepiride dose of 2 mg in a $2{\times}2$ crossover study. There was a one-week washout period between the doses. Plasma concentrations of glimepiride were monitored by a LC-MS/MS for over a period of 12 hr after the administration. $AUC_t$ (the area under the plasma concentration-time curve from time zero to 12 hr) was calculated by the linear trapezoidal rule method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed $AUC_t$ and $C_{max}$. No significant sequence effect was found for all of the bioavailability parameters indicating that the crossover design was properly performed. The 90% confidence intervals of the $AUC_t$ ratio and the $C_{max}$ ratio for Amaryl/Mepiril were log 0.9583-log 1.1357 and log 1.0570-log 1.2376, respectively. These values were within the acceptable bioequivalence intervals of log 0.80-log 1.25. Taken together, our study demonstrated the bioequivalence of Amaryl and Mepiril with respect to the rate and extent of absorption.

Response of Rockfish to the Colored Lights (색광에 대한 조피볼낙의 반응)

  • YANG Yong-Rhim
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.18 no.2
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    • pp.119-123
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    • 1985
  • The author carried out an experiment to find out the response of rockfish, Sebastes schlegeli(Hilgendorf) to the color lights. The experimental tank($360L{\times}50W{\times}55H\;cm$) was set up in a dark room. Six longitudinal sections with 60 cm intervals are marked in the tank to observe the location of the fish. Water depth in the tank was kept 50 cm level. Light bulbs of 20 W at the both ends of the tank projected the light horizontally into the tank. Two different colored filters were selected from four colors of red, blue, yellow, and white, and they were placed in front of the light bulbs to make different colors of light. Light intensity were controlled by use of auxiliary filters intercepted between the bulb and the filter. The fishes were acclimatized in the dark for 50 minutes before they were employed in the experiment. Upon turning on the light, the number of fish in each section was counted 40 times in 30 second intervals, and the mean of the number of fish in each section was given as the gathering rate of the fish. The colors favourited by the fish was found in the order of blue, white, yellow and red in day time, and yellow, blue, white and red at night time. The gathering rate of fish on illumination period was not constant and fluctuated with irregularity. The difference of the gathering rate on two different colors of light was great and the difference was larger in day time than in night time.

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Effect of denture cleansers on surface hardness of resilient denture liners at various time intervals- an in vitro study

  • Pahuja, Rasleen Kaur;Garg, Sandeep;Bansal, Sanjay;Dang, Rajat Harvinder
    • The Journal of Advanced Prosthodontics
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    • v.5 no.3
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    • pp.270-277
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    • 2013
  • PURPOSE. This study was aimed to determine the effect of two chemically distinct denture cleansers and water on the surface hardness of acrylic and silicone based soft denture liners at various time intervals. MATERIALS AND METHODS. Two commonly used commercial resilient liner material were selected based on their chemical composition (silicone- and acrylic-based soft liners) for this investigation. 120 cylindrical specimens were made of $15mm{\times}10mm$ dimensions (according to ASTM: D-2240-64T) in a custom made metal mold. All specimens were stored in artificial saliva throughout the study. Forty specimens were cleansed daily in 0.5% sodium hypochlorite solution; forty were cleansed in sodium perborate and remaining forty specimens were daily rinsed in water. Testing was done at 1 week, 1 month, 3 months and 6 months for surface hardness using a Shore A Durometer. A mean of 3 reading for each sample was subjected to one-way ANOVA, Post Hoc test and pair-t test for statistical analysis. P values of less than 0.05 were taken as statistically significant. RESULTS. Surface hardness of all the samples was significantly higher after a period of 6 months irrespective of the cleansing treatment. Minor changes were observed between control, sodium hypochlorite and sodium perborate groups with time. Greater change was observed in surface hardness of acrylic-based soft denture liners as compared to silicone-based soft liners for all groups, as time progressed. CONCLUSION. Silicone-based soft denture liners performed significantly better in all cleansing treatments than acrylic-based soft denture liners.

A Comparative Analysis on the Efficiency of Monitoring between EWMA and Shewhart Chart in Instrumental Process with Autocorrelation (자기상관이 있는 장치 공정에서 EWMA와 Shewhart 관리도와의 모니터링 효율성 비교 분석)

  • Cho, Jin-Hyung;Oh, Hyun-Seung;Lee, Sae-Jae;Jung, Su-Il;Lim, Taek;Baek, Seong-Seon;Kim, Byung-Keug
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.35 no.4
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    • pp.118-125
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    • 2012
  • When monitoring an instrumental process, one often collects a host of data such as characteristic signals sent by a sensor in short time intervals. Characteristic data of short time intervals tend to be autocorrelated. In the instrumental processes often the practice of adjusting the setting value simply based on the previous one, so-called 'adjacent point operation', becomes more critical, since in the short run the deviations are harder to detect and in the long run they have amplified consequences. Stochastic modelling using ARIMA or AR models are not readily usable here. Due to the difficulty of dealing with autocorrelated data conventional practice is resorting to choosing the time interval where autocorrelation is weak enough then to using I-MR control chart to judge the process stability. In the autocorrelated instrumental processes it appears that using the Shewhart chart and the time interval data where autocorrelation is relatively not existent turns out to be a rather convenient and very useful practice to determine the process stability. However in the autocorrelated instrumental processes we intend to show that one would presumably do better using the EWMA control chart rather than just using the Shewhart chart along with some arbitrarily intervalled data, since the former is more sensitive to shifts given appropriate weights.