• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.6
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• pp.2441-2451
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• 2012

This paper presents the design of a control system for improving performance of a washer fluid heating system (WFHS) which is capable of removing frost, ice, snow and/or other debris from windshield. First, for the WFHS, a modeling process is described, and the extraction of characteristic parameters of the model are made by experimental studies. Design variables that affect on performance of the WFHS are also presented. Secondly, a control system is proposed for improving heating performance of the WFHS, and its performance is verified through experiments. The key feature of the proposed control system is to regulate the current of a booster converter input to the WFHS up to the target value that is set to guarantee heating performance. Target current is calculated by using initial temperature value and employing the mathematical model derived in the paper. Computer simulation and experimental results show that the proposed control system can perform heating operations in a way to satisfy per-determined target performance of the WFHS.

• YAKHAK HOEJI
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• v.59 no.3
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• pp.85-91
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• 2015

Highly active antiretroviral therapy (HAART) has reduced AIDS-related morbidity and mortality; however, it has been associated with metabolic abnormalities including dyslipidemia and dysglycemia depending on the regimens used. The aims of this study were to analyze the prescription patterns of antiretroviral agents and to examine the prevalence of lipid abnormalities among the prescriptions of HAART. The electronic medical records (EMR) of HIV patients were retrospectively reviewed from January 2007 to September 2012 based on our inclusion criteria. The patients who had taken HAART for at least 3 months were included in this study. The lipid profiles of patients on antiretrovirals (ARTs) were collected from his or her laboratory data, and dyslipidemia was defined as total cholesterol (TC) ${\geq}240mg/dL$ and triglycerides (TG) >200 mg/dL. Eighty-four prescriptions were discovered during the study period. Twenty-three prescriptions were the combination of two nucleoside reverse transcriptase inhibitors (NRTIs) and one non-nucleoside reverse transcriptase inhibitor (NNRTI). Fifty-three prescriptions were the combination of two NRTIs and one protease inhibitor (PI) and thirty-nine prescriptions of them included a PI booster. Eight prescriptions were the combination of two NRTIs and one integrase inhibitor. The Incidence of hypertriglyceridemia among the patients receiving HAART was totally about 41.7% (2NRTIs+PI regimen vs. 2NRTIs+NNRTI regimen vs. 2 NRTIs+integrase inhibitor regimen, 52% vs. 12.5% vs. 25%), but there was no incidence of hypercholesterolemia. This study investigated that the prescription medication patterns and dyslipidemia associated with lipid abnormalities among HIV patients receiving HAART. The types of HAART prescription regimens had an effect on the occurrence of hypertriglycemia. Further studies related to metabolic abnormalities and adverse effects of HIV patients on ARTs are needed in the near future.

• Journal of Korean Society of Water and Wastewater
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• v.34 no.5
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• pp.335-344
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• 2020

Due to global climate change, mega-droughts have occurred frequently. Since long-term droughts make it difficult to secure the water resources, water supply needs to be restricted in a reasonable manner. In the event of limited water supply, the waterworks need to develop a restricted water supply strategy. This study showed that analyzing daily water supply could be used to respond to the first stage of a drought. According to an analysis of Korea's major water authorities, there was about 7~21% of room for daily minimum water supply in case of a drought. Restricting the water supply by lowering pressure is a good strategy for local water authorities with high water leakage rate since leakage is inversely dependent with pressure. For this method, it is necessary to quantify water deficiency and pressure at each node using a simulation. Since DDA-based software is not possible to predict changes in demand at nodes with pressure reduction, WaterGEMS, a PDA software, was used to quantitatively predict water shortages and pressures at each node. Locations where water is deficient need to install booster pumps or to be dispatched with water tank truck and bottled water. Without these support, lowering pressure could not be an option for water works. This paper suggests a method for waterworks to plan a drought by lowering pressure to restrict water supply using daily water supply analysis and PDA based simulation.

• Plant Journal
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• v.9 no.2
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• pp.42-45
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• 2013

The worldwide issue of greenhouse gas reduction has recently drawn great attention to carbon capture and storage(CCS). In this study, we developed a 10,000 ton/year pilot injection plant for geological storage of carbon dioxide. Major components of the pilot plant include a pressure pump, a booster pump, and an inline heater to bring liquid carbon dioxide into its supercritical state. The test results show that the pilot plant readily achieves the injection pressure and temperature, showing satisfactory control performance. The overall power consumption is 2,000 ~ 2,500 W, more than 75% of which consumed by the pressure pump. This study will facilitate varied research on greenhouse gas reduction as the only domestically developed system for geological injection.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.05a
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• pp.159-162
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• 2008

In this study, various cycles of liquid rocket engines were surveyed and specifically gas generator after burning cycle was investigated for upper stage motors. The engines for the upper stage can be categorized into three group based on the cycles and propellants at the diagram. Kerosene engines which adapt the gas generator after burning cycle and are located in the region II, are characterized for high combustion pressure and complexity. This cycle usually needs more than two pumps to use the turbine power efficiently. The fuel line can be divided into the gas generator line and the combustor line, and only the gas generator line is need to be pressured more because the combustion pressure in the gas generator is much higher than that of the combustor. Basically, all the oxidizer goes into the gas generator and than to the combustor, thus the auxiliary LOx pump is not critically necessary. However, for the various reasons, the LOx line requires a booster pump. A gas generator after burning cycle engines produces relatively high specific impuls than that of the open cycle engines. Thus it is suitable for upper stages of launch vehicles.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.2
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• pp.18-25
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• 2017

The study for the combustion characteristics of propellants for nozzleless boosters was carried out. The metal fuels of Al and Zr were introduced into solid propellant formulations in order to enhance the density-specific impulse and the high burning rate with low pressure exponent was investigated as the major combustion characteristic of propellant to design nozzleless boosters. The burning rate of Zr-containing propellant was higher than Al-containing propellant and, $13{\mu}m$ Zr-containing propellant exhibited the burning rate of 35 mm/s (at 1000 psi)and pressure exponent of 0.3282. The benefit of using Al and Zr-containing propellant into nozzleless boosters was demonstrated in these results.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.1
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• pp.28-35
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• 2007

In this paper, an ultra low voltage SRAM design method based on dual-boosted cell bias technique is described. For each read/write cycle, the wordline and cell power node of the selected SRAM cells are boosted into two different voltage levels. This enhances SNM(Static Noise Margin) to a sufficient amount without an increase of the cell size, even at sub 1-V supply voltage. It also improves the SRAM circuit speed owing to increase of the cell read-out current. The proposed design technique has been demonstrated through 0.8-V, 32K-byte SRAM macro design in a $0.18-{\mu}m$ CMOS technology. Compared to the conventional cell bias technique, the simulation confirms an 135 % enhancement of the cell SNM and a 31 % faster speed at 0.8-V supply voltage. This prototype chip shows an access time of 23 ns and a power dissipation of $125\;{\mu}W/Hz$.

• Parasites, Hosts and Diseases
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• v.51 no.2
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• pp.155-163
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• 2013

This study aimed to evaluate the efficacy of fructose-1,6-bis phosphate aldolase (SMALDO) DNA vaccination against Schistosoma mansoni infection using different routes of injection. The SMALDO has been cloned into the eukaryotic expression vector pcDNA3.1/V5-His TOPO-TA and was used in injecting Swiss albino mice intramuscularly (IM), subcutaneously (SC), or intraperitoneally (IP) ($50{\mu}g/mouse$). Mice vaccinated with non-recombinant pcDNA3.1 served as controls. Each group was immunized 4 times at weeks 0, 2, 4, and 6. Two weeks after the last booster dose, all mice groups were infected with 80 S. mansoni cercariae via tail immersion. At week 8 post-infection, animals were sacrificed for assessment of parasitological and histopathological parameters. High anti-SMALDO IgG antibody titers were detected in sera of all vaccinated groups (P<0.01) compared to the control group. Both the IP and SC vaccination routes resulted in a significant reduction in worm burden (46.2% and 28.9%, respectively, P<0.01). This was accompanied by a significant reduction in hepatic and intestinal egg counts (41.7% and 40.2%, respectively, P<0.01) in the IP group only. The number of dead eggs was significantly increased in both IP and IM groups (P<0.01). IP vaccination recorded the highest significant reduction in granuloma number and diameter (54.7% and 29.2%, respectively, P<0.01) and significant increase in dead miracidia (P<0.01). In conclusion, changing the injection route of SMALDO DNA vaccination significantly influenced the efficacy of vaccination. SMALDO DNA vaccination via IP route could be a promising protective and antipathology vaccine candidate against S. mansoni infection.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.4
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• pp.570-575
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• 2002

Effects of active immunization against native 14-mer somatostatin (SRIF, somatotropin releasing inhibiting factor) and its two 14-mer-somatostatin analogues on the milk production in rat mammary cells were studied. Native SRIF, Tyr11-somatostatin (Tyr11-SRIF), and D-Trp8, D-Cys14-somatostatin (Trp8Cys14-SRIF) were conjugated to bovine serum albumin (BSA) for immunogen preparation. Twenty-four female Sprague-Dawley rats were divided into four groups and immunized against saline (Control), SRIF, Tyr11-SRIF, and Trp8Cys14-SRIF at five weeks of age. Booster immunizations were performed at 7, 9, and 11 weeks of age. SRIFimmunized rats were mated at 10 weeks of age. The blood and mammary glands were collected at day 15 post-pregnancy and -lactation. To measure the amount of milk protein synthesis in the mammary gland, mammary cells isolated from the pregnant and the lactating rats, were cultured in the presence of $^3H$-lysine. No significant differences in growth performance, concentration of growth hormone in the circulation, and the amount of milk protein synthesis were observed among the groups. Inductive levels of serum anti-SRIF antibody in the SRIF and Tyr11-SRIF groups but not in the Trp8Cys14-SRIF group, were significantly higher than that of the control group during the pregnancy and lactation periods. The result suggests that active immunization against native 14-mer SRIF and Tyr11-SRIF was able to induce anti-SRIF antibodies, but did not affect the milk protein synthesis.

• YAKHAK HOEJI
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• v.54 no.6
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• pp.494-499
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• 2010

We have been focussing on discovery of natural compounds that have immunoregulatory activities for many years. In the present study, we investigated if chlorogenic acid (CRA), a polyphenolic compound, has an immunoadjuvant activity. Prior to examining the immunoadjuvant activity, effect of CRA on proliferation of T- or B-lymphocyte was determined. Results showed that CRA enhanced the proliferation of those lymphocytes in dose-dependant manner (P<0.05), and the proliferation enhancement by CRA was appeared to be more effective to B-cells than to T-cells. Based on these observations, it was tested with bovine serum albumin (BSA) and Candida albicans cell wall (CACW) as antigenic sources if CRA has an immunoadjuvant activity. In experiments, BSA alone or a mixture of BSA plus CRA was injected intraperitoneally to mice (BALB/c strain). For a negative control, mice were given only diluent (DPBS) by the same route. In other experiment, CACW was tested by the same way as did with BSA. Three weeks after the first immunization these animals were boosted. Antisera collected from the mice one week after the booster were analyzed by ELISA. Results displayed that the induction of anti-BSA antibody was increased in mice that received the mixture of BSA and CRA as compared to anti-BSA induction in BSA only-given mice groups (P<0.05). In case of CACW, a similar observation as did with BSA was made, resulting in that there was app. 40% increased production of the anti-CACW antiserum from the combination (CACW plus CRA)-received mice as compared to antiserum induction from CACW alone-given animals. Taken all together, these data indicate that CRA has an ability of enhancing antibody production regardless of nature of antigenic sources. Presumably, activation of B-cell proliferation by CRA may plays an important role in the immunoadjuvant activity of the polyphenolic compound.