• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.150-157
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• 2005

Generally, the flow hunting is observed in almost all of the orifice meters but the intensity of the flow hunting is different at each metering system. So, we were getting some Questions as follows; why such a difference occurs and whether it influence to metering error rate or not. To investigate the flow hunting characteristics, we are trying to examine the flow characteristics around the orifice meter when the transient flow or pressure is generated at after the PCV(Pressure Control Valve) by 3D CFD method. And we have compared numerical results with experimental results at M - PCV station in order to clarify the relations with both the metering-pipeline diameter and flow rate. Finally, we can show some major factors influencing to the flow hunting and propose some correcting scheme of the flow hunting equation.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.41-45
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• 2006

To get accurate positions of GPS antennas, one should apply phase center variations (PCV) corrections in the data processing. Until recently, relative calibrations, originally proposed by National Geodetic Survey of United States, were the international standard. However, in late 2006, International GNSS Service will switch to absolute calibration methods. In this study, we compared the position differences caused by different PCV models, and their effects on the calculations of Precipitable Water Vapor (PWV) in the atmosphere. Data from ${\sim}40$ permanent GPS stations in Korea were processed and we found that the vertical position differences reach up to 5 cm, depending on the model selected. Also the PWV values varied quite significantly: the maximum bias in the computed PWV values was ${\sim}4$ mm.

• Journal of Veterinary Clinics
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• v.17 no.2
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• pp.340-345
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• 2000

The purpose of the present study was to evaluate the possibility of application of pediatric hemodialysis system to dogs weighing less than 6 kg. Six healthy dogs (B .W, 3-6 kg) were used_ Experimental end-stage renal failure was induced by bilateral nephrectomy or bilateral ligation of ure-ters. Hemodialysis was performed when blood urea nitrogen (BUN) value increased over 90 mg/dl and every other day thereafter. Daily investigated parameters included clinical clinical signs such as vomiting, fecal appearance and activity and laboratory data such as PCV, WBC, RBC, BUN, creatinine, Ca, P, $Na^+ Cl^-and K^+$During hemodialysis treatment, BUN and creatinine values were measured hourly. Severe vomiting and inappetence were shown 2 days after infliction of kidney disorder and melena and mucous faces were observed 3 days. The signs were not corrected by hemodialysis treatment. Avel- age hemodialysis treatment time was $5.5 {\times} 0.7$,/TEX> hours until BUN value decreased to normal range. Abnor- mal hematological and electrolytes values were reduced within normal levels after hemodialysis treatments. The complications oft hemodialysis included vomiting, nausea, obstruction of intravascular catheter, tremor, seizure, temporary visual loss and continued decrease in PCV It is suggested that pediatric hemedialysis system can be applied to acute renal failure and acute toxicity. Further works on improvements in maintaining patency of catheter and in managing the complications of hemo- dialysis should be conducted.

• Korean Journal of Veterinary Service
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• v.30 no.3
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• pp.467-472
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• 2007

Eurasian black vulture (Aegypius monachus) belongs to family Accipitridae and is a raptor preying small birds and mammals. It is a wintering bird residing from the mid of November to the late of March in Korea. Although Eurasian black vulture population wintering at Korea is gradually increased, the efficient rescue and treatment for injured Eurasian black vultures are still problematic, due to lack of basic data. Therefore, in this survey, to obtain basic resources for establishing more efficient rescue system, we surveyed the number of Eurasian black vultures wintering at Gangwon province, wintering ecology and injury state of Eurasian black vulture. Survey area was Togyo reservoir at Cheorwon, Seonan basin at Yangoo and Wolsong reservoir at Chuncheon from November 2004 to March 2005. From 12 rescued Eurasian black vultures, physical examination, total plasma protein (TPP) and packed cell volume (PCV) were measured. To survey injury state of Eurasian black vultures wintering at Gangwon province, we surveyed the cause, morbidity and mortality from 103 Eurasian black vultures, based on medical records from animal rescue teams. The number of eurasian black vultures were gradually increased from November, peaked at Feburary, then steeply decreased at March. Eurasian black vultures showed the most vigorous activity around 1 PM within a day. In physical examination, mean body weight was $9.6{\pm}1.22kg$, body length was $1130{\pm}45.4mm$. No statistically significant difference in body weight and length between male and female eurasian black vultures was observed. Mean PCV was $40.2{\pm}2.7%$, while mean TPP was $5.86{\pm}0.8mg/dl$. The most common cause of injury and mortality was intoxication, while that of morbidity was fatigue.

• Journal of Veterinary Clinics
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• v.20 no.4
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• pp.437-442
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• 2003

To examine the in vivo immunostimulating effect of conjugated linoleic acid (CLA) in pigs, the change of peripheral blood cells and the phagocytic response of phagocytes were evaluated. Spayed male pigs, 80 kg of average body weight, fed a diet containing either 0.5% 10t-12c CLA or 0.5% CLA mixture (mostly 9c-11t CLA and 10t-12c CLA) for 4 weeks. The change of blood cell values (PCV, WBC, differential count of WBC) and the phagocytic activities of phagocytes were evaluated on week 0, 2, 4, and 5, respectively. There were no change in the PCV values regardless of CLA supplement. The number of WBC, especially neutrophils, in pigs fed a diet with CLA was significantly increased (p<0.05 to 0.01) when compared with control pigs fed a diet without CLA. The phagocytosis of peripheral blood mononuclear cell (MNC) and peripheral blood polymorphonuclear cells (PMN) were analyzed by a flow cytometry system. There was no change in the phagocytic activity of MNC and monocyte-rich cells regardless of CLA supplement. However, the phagocytic activity of PMN composed by approximately 95% neutrophils was remarkably increased (p < 0.05 to 0.01) on week 2, 4, and 5 as compared wth control pigs. These results suggested that supplement of CLA into pigs induces the increase of neutrophil number and the enhancement of neutrophil phagocytosis.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.5
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• pp.549-555
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• 2016

This research was performed to determine the oil separation characteristics of the specially designed oil filter installed in a PCV cylinder head passage. The oil filter was specially designed with fleece for separating oil mist from blow-by gas. The fleece, made of fiber fabric material, is placed in the oil filter case to absorb oil mist with a small pressure drop during blow-by gas through the filter. To do this, 3-D CFD analysis was simulated for the simplified PCV system with the oil filter using the commercial code, Ansys CFX. Results showed that the oil filter's efficiency with fleece sharply increased as oil droplet size increased.

• The Journal of Korean Institute for Practical Engineering Education
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• v.3 no.1
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• pp.9-14
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• 2011

The expansion work that is wasted through the irreversible expansion through the PC valve of decompression process of the natural gas governor station can be recovered by replacing the process by an isentropic expansion. The energy and exergy analyses for the two decompression process models of power producing and current decompression process model are presented. Analysis results showed that the exergy by gas supply is 56.29%, the exergy by producing power is 32.12 % in case of preheating system and 22.52% in case of non-preheating system. The dead exergy at the PCV is generated much more network. As these results, the usefulness of exergy analysis is verified.

• Journal of Drive and Control
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• v.15 no.3
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• pp.36-42
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• 2018

Agricultural tractors require frequent shifting to improve operation efficiency, and PST (Powershift Transmission) is considered as a suitable transmission. However, due to the inherent characteristics of the PST, shocks arise during shifting, which imparts a negative effect on the operator. Therefore, in order to improve the transmission performance of the tractor PST, researches on various methods including the hydraulic system circuit, the engine input speed control, and the mechanical system of the transmission are steadily being conducted. In this study, in order to reduce the impact of PST on a shift based on SimulationX software, we analyzed the characteristics of the input signal of PCV (Pressure Control Valve) through sensitivity analysis and verified the simulation model through actual vehicle test. Optimization was performed for minimizing the shift shock for some of the parameters of the input signal at constant temperature and RPM conditions.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.3
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• pp.74-84
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• 2005

This paper include the investigation of finding the system characteristics of facility by simulating open-type turbo-pump fed system, which has commercial control valves, using AMESIM (Advanced Modeling Environment Simulation) commercial software. After developing a flight-type control valve on the basis of the results, the system characteristics of facility for control and valve tests is estimated. Especially, one of purposes of this paper is to find PID value of each commercial control valve in the facility for system test. To find suitable control logic, PI and PID modes are also compared. This paper also introduces design parameters of valve and equipment for thrust control and TDS simulation, which are using control valves.

• Journal of Veterinary Clinics
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• v.16 no.2
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• pp.439-442
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• 1999

An animal health monitoring system in Gyeongnam area (near-Chinju) was studied to evaluate the environmental risk factors, physical examinations and 4 disease entities(abomasal displacement, traumatic reticulopericarditis ＆ -peritonitis, milk fever and lameness) in 40(34 in second year)dairy herds (total 1253 dairy cattle). In feeding environments, we examined housing system, forage percentage in ration, stall types, playground, cleanness of stall. In housing system, most of herds (60%) have tie-stall types and 36 herds are open-type housing. The forage ratio of ration was less than 50% in most of herds (67%). 39 herds had their own playgrounds and the frequency of playground cleanness was irregular, Physical examinations included the T(temperature), P (pulse), R (respiration), abnormalities of superficial lymph nodes, claw examination and total CBC with blood from tail veins. T, P, R are within normal limits (T : 38.1$\pm$0.6$^{\circ}C$, P : 84.6$\pm$12.9/min., R : 24.0$\pm$7.6/min. ,respectively), the swelling of lymph nodes were shown in 13 cattle and overall claw trimming was required in 3 herds. In blood examination, 23 cattle showed leuko-cytosis and 7 cattle showed low RBC and hemoglobin level, the other cattle were within normal limits (WBC : 8.90$\pm$2.06 10$^3$/ul., RBC : 6.36$\pm$1.02 10$^{6}$ ul, Hb : 9.83$\pm$ 1.20 g/dl PCV : 27.43$\pm$5.67 %, respectively). In 4 disease entities, we found some metallic foreign bodies in men of 13 cattle, which had predisposing factors of traumatic reticulopericarditis and reticuloperitonitis, 13 abomasal displacement, 51 milk fever and lameness in 39 cattle.