• Journal of Korean Society of Transportation
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• v.17 no.1
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• pp.131-139
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• 1999

The quality of progression at signalized intersection has the largest potential effect. TRANSYT-7F is widely used to estimate the signal progression delay, but the progress of collecting and executing the compute program appears to be rather cumbersome. The research is to develop the analytical and progressing platoon delay model that is as simple as the methodology of HCM and familiar with the output of simulation model. The general approach to this research was conducted to examine the Rouphail and NCHRP 339 methodology together with the existing progression delay model (TRANSYT-7F. HCM). The scope is contained to be applicable only to cycles with no overflow queue and to obtain a comprehensive evaluation of the effects of changes in the quality of traffic signal progression on stopped delay and to be analyzed a simple mathematical method. The principle assumption for this model is that secondary flows is dispersed and partly mixed with average flow of the primary progressed flow. A second assumption is that through flow is consisted with the part of saturation flow at the front of it and the part of average flow at the rear of it. The delay equations vary for two arrival. The conclusion of this study could be summarized as 1)The evaluation of this model was consistently similar to that of TRANSYT-7F, 2) Platoon pattern has the real traffic flow characteristics. 3) The computing process of progression delay is made to have simple logic and easy calculation by integration, 4) This model could be estimated to be applied in almost all case.

• Journal of the Korean Chemical Society
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• v.38 no.11
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• pp.792-799
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• 1994

The spectral changes of 3,3'-diethyl oxacarbocyanine(DOC) in the aqueous solution and in the presence of polyacrylic acid(PAA) were studied by means of absorption and fluorescence spectroscopy. The spectral change of DOC in the aqueous solution with concentration changes is attributed to the formation of dimer. In the presence of PAA, the characteristic changes of metachromatic band with changes of P/D (the ratio between available binding site and the dye concentration) are found and the discussions are made in terms of stacking theory. A kinetic study of the interaction between DOC and PAA was also investigated by the absorption and fluorescence stopped-flow spectroscopy. The observed relaxation effect in PAA-DOC system can be described quantitatively by assuming two relaxation processes occur.

• Journal of the Korean Chemical Society
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• v.39 no.8
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• pp.604-610
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• 1995

The interaction between 3,3'-dipropyl oxacarbocyanine and poly(styrenesulfonate) has been studied by means of absorption and fluorescence spectroscopic methods. The results was interpreted by stacking model. The kinetic studies of the interaction between 3,3'-dipropyl oxacarbocyanine and poly(styrenesulfonate) were carried out by the absorption and fluorescence spectroscopic stopped-flow methods. The observed relaxation effect in DPC-PSS system was described quantitatively by assuming two relaxation processes. The dependence of rate of reaction on the salt concentration of the solution was also studied. The results are consistent with the two-step mechanism.

• The Korean Journal of Pharmacology
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• v.30 no.2
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• pp.255-260
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• 1994

There are some reports about the influences of free fatty acids on the albumin binding of drugs. But they were concerned to the limited free fatty acids, mostly of azapropazone-warfarin bidning site bound drugs and determination of dissociation and association constants by stopped flow technique. These data were not enough to make conculsions for the general tendency of free fatty acid to albumin binding. Therefore the influence of various saturated fatty acids of $C_{10{\sim}20}$, oleic acid and linoleic acid as unsaturated fatty acids to albumin binding of warfarin and dansylsarcosine were studied by equilibrium dialysis. The concentration of free drug was determined by spectrophotometer according to the molar ratios of 0, 0.5, 1, 2 and 4 between free fatty acid and albumin. There were significant increasing in the free durg concentration of warfarin and dansylsarcosine when the molar ratio for capric acid, lauric acid and palmitic acid was 4. The free warfarin concentration was increased significantly at a molar ratio of 4 between oleic acid and albumin. Therefore the albumin binding of durgs can be variated significantly by increased free fatty acid of diabetics and cause to the pharmacokinetic variation between healthy and diabetics.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.107-112
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• 2010

When we design the control system used Programmable Logic controller(PLC), if we program a Sequential Function Chart(SFC), It is easy to understand the sequential flow of control, to maintenance the controller and to describe a program. SFC language is programmed by a single sequence, a select sequence and a parallel sequence. In a select sequence, when the select step is error, the whole process is stopped. If the error step has no connection the whole process, the loss is down when we debugging the program without stopping the whole process. Therefore, this thesis shows the efficient method of remote control for select sequence and we confirmed its feasibility through actual example.

• The KSFM Journal of Fluid Machinery
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• v.8 no.4 s.31
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• pp.20-26
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• 2005

When the pumps are started or stopped for the operation or tripped due to the power failure, the hydraulic transients occur as a result of the sudden change in velocity. The field tests on the waterhammer were carried out for Pangyo booster pumping station in which had six booster pumps and two in-line pumps with the motor of output 1,700 kW, respectively. The booster pumping station was equipped with the pump control valve as the main surge suppression device, and the surge relief valve as auxiliary one. But the pump control valve had not early controlled in the planned closing mode, the slamming occurred to the valve of which abruptly closed during the large reverse flow. Because the positive pressure wave caused by the pump failure was superposed on the slam surge, the upsurge increased so extremely that the pump control valve was damaged. After the air chambers were additionally installed in the booster pumping station, it was preyed that the water supply system acquire the safety and reliability on the pressure surge.

• Journal of Power System Engineering
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• v.18 no.3
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• pp.51-58
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• 2014

Injection molding simulation provided optimized design results by analyzing quality problems while the product is in assembly or in the process of manufacturing with make automobile plastics. Frequent change of design, change of injection molding, repetition of test injection which was held in the old way can now be stopped. And quality upgrade is expected instead. This report deals with the effect which the position of injection molding automobile console gate and number has on product quality including pressure at end of fill, bulk temperature at end of fill, shear stress of end of fill, residual stress at post filling end, product weld lines and warpage results. Simpoe-Mold simulates the complete manufacturing process of plastic injected parts, from filling to warpage. Simpoe-Mold users, whether they are product designers, mold makers or part manufacturers, can identify early into the design stage potential manufacturing problems, study alternative solutions and directly assess the impact of such part modification, whatever the complexity and geometry of such parts, shell part as plain solid parts.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.10
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• pp.5134-5139
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• 2013

Ladder Diagram(LD) or Sequential Function Chart(SFC) is used for the design of complex modern control system with Programmable logic controller(PLC). LD is the most widely utilized among PLC standard language. But recently, SFC is used frequently. SFC is very easy to grasp the sequential flow of control logic but is difficult for describing combinational logic. When the interrupt factor is occurred, the main program is stopped. And after the interrupt program is completed, the main program is restart. Therefore the more complex the interrupt program, the main program is interrupted downtime will be that much longer. In this paper, we propose the method for interrupt implementation without the dwell time of the main program by SFC language and confirm his feasibility through the simulation.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.208-216
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• 2004

The waterhammer occured when the pumps are started or stopped for the operation or tripped due to the power failure, the hydraulic transients occur as a result of the sudden change in velocity. The field tests of the waterhammer were carried out for PanGyo booster pumping station. The PanGyo pumuing station was installed booster pump of 6 sets and in-line pump of 2 sets. The main surge suppression device was equipped with the pump control valve and the surge relief valve as auxiliary. However, the pump control valve had not early controlled in the planned closing mode, and the slamming occurred to the valve of which abruptly closed during the large reverse flow. Because the pressure wave caused by the pump failure was superposed on the slam surge, the upsurge increased so extremely that the shaft of the valve was damaged. After the addition surge suppression device was equipped with air chamber. Further more in-line pump is needed surge suppression device that the pumping station acquired the safety and reliability for the pressure surge.

• The KSFM Journal of Fluid Machinery
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• v.7 no.1 s.22
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• pp.51-57
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• 2004

The waterhammer has recently become more important because the pumping stations were big and the systems conveying the fluid through the large and long transmission pipelines were complex. When the pumps are started or stopped for the operation or tripped due to the power failure, the hydraulic transients occur as a result of the sudden change in velocity As the pressure waves are propagating between the pumping station and the distributing reservoir, the pressure inside the pipe drops to the liquid vapor pressure with the pipeline profile, at which time a vapor cavity forms, and finally the column separation occurs. If the pressure in the pipe is less than the atmospheric pressure, the pipe can be collapsed and destroyed after the water columns separated by the vapor cavity rejoin. During the reverse flow, the pressure is so abnormally increased at the pumping station that the accident of flooding may happen due to the failure of system. In this paper, the field tests on the waterhammer by the startup, stoppage, and power failure of a centrifugal pump were carried out for Yongma transmission pumping station in Seoul. The experimental results were compared with that of the numerical calculations, in which results the procedure of controlled pump normal shut-down and the two-step closing mode of controlling the ball valve for pump emergency stop are proposed to reduce the pressure surge.