• Journal of Korean Society for Geospatial Information Science
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• v.24 no.1
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• pp.69-80
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• 2016

Some studies were conducted for the purpose of minimizing total clearance time for rapid evacuation from the indoor spaces when disaster occurs. Most studies took a long time to calculate the optimal evacuation route that derived minimum evacuation time. For this reason, this study proposes an evacuation route assignment algorithm that can shorten the total clearance time in a short operational time. When lots of exits are in the building, this algorithm can shorten the total clearance time by assigning the appropriate pedestrian traffic volume to each exit and balances each exit-load. The graph theory and greedy algorithm were utilized to assign pedestrian traffic volume to each exit in this study. To verify this algorithm, study used a cellular automata-based evacuation simulator and experimented various occupants distribution in a building structure. As a result, the total clearance time is reduced by using this algorithm, compared to the case of evacuating occupants to the exit within shortest distance. And it was confirmed that the operation takes a short time In a large building structure.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.6
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• pp.1017-1023
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• 2017

Duration induced by freeway crashes has a critical influence on traffic congestion. In general, crash duration composes detection and verification, response, and clearance time. Of these, the crash clearance time determined by a crash clearance team has attracted considerable attention in the freeway congestion management since the interest of the first two time stages faded away with increasing ubiquitous mobile phone users. The objective of this study is to identify the critical factors that affect freeway crash clearance time using a Cox's proportional hazard model. In total, 6,870 crash duration data collected from 30 major Korean freeways in 2013 were used. As a result, it was found that crashes during the night, with trailer or larger size truck, and in tunnel section contribute to increasing clearance time. Crashes associated with fatality, completed damage of crashed vehicle (s), and vehicles' fire or rollover after crash also lead to increasing clearance time. Additionally, an increase in the number of vehicles involved resulted in longer clearance time. On the other hand, crashes in the vicinity of tollgate, by passenger car, during spring, on flat section, and of car-facility type had longer clearance time. On the basis of the results, this paper suggested some strategic plans and mitigation measures to reduce crash clearance time on Korean freeway systems.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.6
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• pp.133-143
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• 2018

Roundabouts are generally installed at which traffic and pedestrian volume is relatively small intersections, and hence traffic can flow one direction around a circular island without traffic lights. A number of researches for roundabout signal metering have been processing ways to deal with operation efficiency drops in conditions of unusual traffic and pedestrian volume increases. However, there is still a shortcoming exists in previous operation algorithm does not consider the hidden vehicles between yield lines and detectors and queueing vehicles in circular lanes. These queueing vehicles between them can be cleared by introducing the queue clearance time. The purpose of this research is developing a real time signal metering operation algorithm by considering the vehicle queue clearance time. The results of varying queue clearance time application show that there is a substantial average vehicle delay reduction in VISSIM Com-Interface simulation. When the total number of entering vehicle is 3,200~4,800 vehicle/hour with varying queue clearance time application 21~50 seconds gives average delay reduction per vehicle by 16.1~71.7%.

• Archives of Pharmacal Research
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• v.13 no.3
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• pp.233-239
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• 1990

The efect of acute renal failure (ARF) on the pharmacokinetics o sulfobromophthalein (BSP) was investigated in order to elucidate if renal failure modifies the hepatic metabolism of drugs. ARF was induced by intravenous (iv) injection of uranyl nitrate (UN) to rats (5 mg/kg) five days before the experiment. Area under the plasma concentration-time curve (AUC)of BSP after portal vein (pv) injection increased by 2-fold and total body clearance ($CL_1$) decreased one half (p <0.01) in UN-induced ARF (UN-ARF) rate compared to the control rats. But the plasma disappearance of BSP after iv injection did not differ significantly between control and UN-ARF rats. Since BSP is excreted via the liver, $CL_1$ represented the approximate hepatic clearance of BSP. Therefore, the decrease in $CL_1$ represented the approximate hepatic clearance of BSP. Therefore, the decrease in $CL_1$ represents a decrease in hepatic intrinsic clearance ($CL_{int}$) for BSP since plasma free fraction ($f_p$) of BSP was not affected by UN-ARF. The content of hepatic cytoplasmic Y-protein, which catalyzes BSP-glutathione conjugation and limits the trasfer of BSP from blood to bile, increased significantly (p < 0.01), however its binding activity (BA) for BSP was decreased significantly (p <0.01) by UN-ARF. The decrease in $CL_{int}$might have some correlation with the changed characteristics of hepatic Y-protein, specifically its decreased BA for BSP.

• The Korean Journal of Nuclear Medicine
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• v.22 no.2
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• pp.181-185
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• 1988

Since hepatocyte clearance, leading edge parencymal transit time and biliary excretion can be evaluated separately with hepatobiliary scan using $^{99m}Tc-DISIDA$, hepatobiliary scan may be useful in differentiating intrahepatic cholestasis from extrahepatic cholestasis. Excretory liver function was analysed in 13 healthy subjects and 11 patients with clinically suspected hepatocellular disease and 9 patients with extrahepatic biliary obstruction confirmed by surgery, radiological and clinical evidence. Indices of total liver activity (% TLA), liver parechymal uptake (% LPU), heart pool clearance (% HPC) and liver-heart rate (% LHR) were calculated from time activity curve over heart and liver. Compared with healthy subjects, significant reduction (p<0.05) in total liver activity (% TLA) and liver-heart rate (% LHR) was observed in all patients group. But no useful indices was demonstrated in differentiating hepatocellular disease from extrahepatic biliary obstruction.

• Journal of Pharmaceutical Investigation
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• v.38 no.6
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• pp.399-403
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• 2008

The aim of this study was to evaluate the difference of analytical methods for the pharmacokinetic study of bromosulfophthalein (BSP), an indicator of hepatobiliary function. The plasma and bile concentrations of BSP after intravenous administration were measured according to custom UV spectroscopy and HPLC, respectively. Plasma concentration of BSP measured by UV spectroscopy was similar to that measured by HPLC. There was no significant difference in the distribution volume, total body clearance, area under the curve and mean residence time of BSP between different analytical method groups. However, bile concentration of BSP measured by UV spectroscopy was overestimated compared with concentration measured by HPLC method. Biliary clearance of BSP obtained from UV spectroscopy method was almost 3 times higher than that obtained from HPLC method. Thus, a feasibility of UV spectroscopy method for high throughput pharmacokinetic evaluation of BSP was limited to the study based on the plasma concentration of BSP, not bile concentration.

• Archives of Pharmacal Research
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• v.27 no.2
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• pp.254-258
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• 2004

The purpose of this study was to investigate the pharmacokinetic alteration of diltiazem and its main metabolite, deacetyldiltiazem, after oral administration of diltiazem in rabbits with or with-out cimetidine co-administration. The area under the plasma concentration-time curve (AUC) of diltiazem was significantly elevated in rabbits pretreated with cimetidine, suggesting that the oral clearance, an index of intrinsic clearance, may be decreased by the cimetidine treatment. Consistent with the increased AUC by the treatment, peak plasma concentration ($C_{max}$) for diltiazem was also elevated. Apparent volume of distribution normalized by the bioavailability (($V_{d}$/F) of diltiazem increased sigrificantly in rabbits pretreated with cimetidine increased. Taken together with the fact that the first pass metabolism for diltiazem is the primary determinant for the oral bioavailability, these observations indicate that increases in the oral clearance and (($V_{d}$/F may be a manifestation of the decreased first pass metabolism. Consistent with the hypothesis, the AUC of deacetyldiltiazem was significantly decreased in rabbits with cimetidine treatment. Ratio of deacetyldiltiazem to total diltiazem in the plasma was significantly decreased in rabbits with cimetidine treatment. These observations suggested that the metabolism of diltiazem to deacetyldiltiazem was reduced by cimetidine treatment and that the dosage of diltiazem should be adjusted when the drug is co-administered chronically with cimetidine in a clinical setting.

• Korean Journal of Clinical Pharmacy
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• v.20 no.3
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• pp.200-204
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• 2010

The purpose of this study was to investigate the effect of ticlopidine on the pharmacokinetics of nimodipine in rats. Pharmacokinetic parameters of nimodipine were determined in rats after oral administration of nimodipine (16 mg/kg) with or without ticlopidine (3 or 10 mg/kg). Ticlopidine inhibited cytochrome P450 (CYP)3A4 activity. Ticlopidine significantly (p<0.05, 10 mg/kg) increased the area under the plasma concentration-time curve (AUC) of nimodipine and ticlopidine significantly (p<0.05, 10 mg/kg) prolonged the terminal half-life ($t_{1/2}$) of nimodipine. Ticlopidine significantly (p<0.05, 10 mg/kg) decreased the total body clearance ($CL_t$). The absolute bioavailability (AB%) and relative bioavailability (RB%) of nimodipine by presence of ticlopidine were increased by 14% and by 42%, respectively, compared to the control. Based on these results, the increased bioavailability of nimodipine might be due to inhibition of the metabolizing enzyme cytochrome P450 (CYP)3A4 in the liver or intestinal mucosa and/or reducing total body clearance by ticlopidine.

• Korean Journal of Clinical Pharmacy
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• v.8 no.1
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• pp.23-28
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• 1998

The pharmacokinetics of atenolol (25 mg/kg, i.v.) in the folate-induced renal failure rabbits was studied. Renal failure was induced by the i.v. injection of folate (50, 100, and 200 mg/kg). At folate dose of 100 and 200 mg/kg, the serum creatinine concentration (Scr) and blood urea nitrogen (BUN) increased significantly compared with control rabbits. Plasma concentrations and AUC of atenolol increased significantly at folate dose of 100 and 200 mg/kg. The elimination rate constant $(K_{el})$ and total body clearance $(CL_t)$ of atenolol decreased significantly, and half-life ($t_{1/2}$) and mean residence time (MRT) of atenolol increased significantly at folate dose of 100 and 200 mg/kg. The serum creatinine concentration $(S_{cr})$ correlated well (p<0.05) with half-life $(t_{1/2})$ and elimination rate constant $(K_{el})$ of atenolol, as well as BUN with AUC and total body clearance $(CL_t)$ of atenolol.

• Journal of Nutrition and Health
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• v.25 no.6
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• pp.461-467
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• 1992

Although intravenous fat emulsions are well accepted as a consituent of a total parenteral nutrition regimen it is still controversial how much it can be used and who to use it in consideration of physical situation of useres. In this study the effect of two marketed lipid formulas on serum lipids change was investigated. Each lipid formula was injected to twelve normal adult volunteers and a set of blood samples was drawn at 5 minute interval during the experiment. Changes of triglycerides. free fatty acids free glycerol total cholesterol and phospolipids in the serum wre determined. To calculate serum lipids clearance the phar-macokinetics of serum triglyceride fractional removal rate(k) and half-life time(t/2) were calculated using intravenous fat tolerance-test(IVFTT) None of the parameters determined in this experiment was statistically different between two marketed formulas. In summary the bolus injection of the lipid formulas did not produce any adverse effects and their elimination kinetics from the blood stream were similar.