• 전기의세계
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• v.30 no.7
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• pp.454-459
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• 1981

The aim of study in this paper is that in a system drive of the converter-inverter fed induction motor, the minimum input power can be maintained by control the voltage and frequency of the motor. In theoretical and experiment results describtion motor efficiency is improved by properly varying the ratio v/f. At lightly load condition, for example its efficiency was improved from 44% to 66% as the ratio of v/f varied from 1 to 0.57.

• Korean Journal of Veterinary Research
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• v.39 no.3
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• pp.545-553
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• 1999

A 474-base pair segment covering the hypervariable region of VP2 gene from six Korean infectious bursal disease virus(K-IBDV) isolates(K1, K2, SH/92, 225, 269, 310) and one attenuated IBDV(DAE) were amplified using RT-PCR, sequenced, and compared with published sequences for IBDV. K-IBDV isolates(K1, K2, SH/92, 225, 269) and foreign very virulent(vv) IBDV strains had 94.93~100% amino acid sequence similarity. K-IBDV isolate 310 and other K-IBDV isolates had 84.31~86.07% amino acid sequence similarity. Attenuated strain(DAE), like other attenuated strain, has substitution at positions 279(D to N) and 284(A to T) as well as in the serine-rich heptapeptide region. Five K-IBDV isolates except 310 isolate share unique amino acid residues at positions 222(A), 256(I), 294(I) which are not present in other standard and attenuated strains. At the two hydrophilic region, K-IBDV isolates except 310 isolate had identical amino acids comparing with Belgium vv IBDV 894VB but had four amino acid substitutions comparing with Chinese vv IBDV F9502. The SWSASGS heptapeptide is conserved in all K-IBDV isolates. The sequence of K-IBDV isolate 310 was markedly different from other IBDV strains, evolving from a separate lineage than the others. By phylogenetic analysis, Five K-IBDV isolates except 310 isolate were categorized in one group with foreign vv IBDV isolates but K-IBDV isolate 310 was categorized in a separate group which was differentiated from other compared IBDV strains.

• Korean Journal of Remote Sensing
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• v.34 no.6_1
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• pp.969-979
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• 2018

This paper presents reflection symmetry of polarimetric SAR over the Amazon rainforest in terms of correlation coefficients between the pairs of HH- and HV-pol and VV- and VH-pol data by ALOS PALSAR. The reflection symmetry is defined as a non-zero correlation between HH- and HV-pol and VV- and VH-pol over natural distributed targets, and is a fundamental assumption for cross-talk calibration coefficient computation and for three-component decomposition for polarimetric SAR data. The Amazon rainforest is especially one of the common global reference sites for the reflection symmetry. The correlation coefficients for the pairs of reflection symmetry obtained in this study range from 0.018 to 0.097. The results imply that there exists a non-negligible dependency between co-pol and cross-pol in the distributed natural targets, and consequently the non-zero correlation must be considered as a potential contribution to errors of spaceborne SAR polarimetry to some extent.

• Journal of Chest Surgery
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• v.57 no.2
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• pp.225-229
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• 2024

Venovenous (VV) extracorporeal membrane oxygenation (ECMO) is a lifesaving technique for patients experiencing respiratory failure. When VV ECMO fails to provide adequate support despite optimal settings, alternative strategies may be employed. One option is to add another venous cannula to increase venous drainage, while another is to insert an additional arterial return cannula to assist cardiac function. Alternatively, a separate ECMO circuit can be implemented to function in parallel with the existing circuit. We present a case in which the parallel ECMO method was used in a 63-year-old man with respiratory failure due to coronavirus disease 2019, combined with cardiac dysfunction. We installed an additional venoarterial ECMO circuit alongside the existing VV ECMO circuit and successfully weaned the patient from both types of ECMO. In this report, we share our experience and discuss this method.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.154-158
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• 2009

The vortex ventilation system (VV) which uses a rotating finned swirler installed coaxially with the exhaust duct is a very effective local ventilator. VV can enhance the capture depth by a factor of 3-5 compared to the conventional exhaust hood, in the absence of any solid walls nearby. In real situations there may exist ceiling, side wall and floor, all of which can affect the flow field and suction performance by way of the no-slip condition on the walls. 3D CFD simulation was performed in order to see the effect of the floor on the capture performance of the VV. The presence of floor reduced suction flow velocity, and increased the critical rotational speed which is the rotational speed required for stable vortex formation. Flow velocity profile along the axis could be well approximated by a universal functional form when the distance from the exhaust inlet is non-dimensionalized by the distance to the floor. Capture depth, define by the distance from the exhaust inlet to a point of velocity decreased to 10% of that at the inlet, is reduced by about 10% when the floor distance is 6 times the exhaust hood diameter.

• Journal of Chest Surgery
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• v.57 no.3
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• pp.319-322
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• 2024

Venovenous extracorporeal membrane oxygenation (VV ECMO) is often used in cases of severe respiratory failure, especially in patients considered for lung transplantation. However, because many lung diseases can ultimately result in right heart failure, the treatment of secondary right heart failure can present a challenge when the patient is already under VV ECMO support. In such cases, an oxygenated-right ventricular assist device (OxyRVAD) can be used. OxyRVAD is designed to maintain anterograde blood flow and prevent right ventricular distension. Moreover, the pulmonary arterial cannula can be inserted percutaneously. We report a case in which percutaneous OxyRVAD was successfully implemented to manage right heart failure in a patient with respiratory failure who was on VV ECMO.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.82-82
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• 1997

The hepatitis B virus(HBV) is a small, enveloped virus with a circular, double-stranded DNA genome. HBV causes active and chronic hepatitis worldwide, including Korea, and is considered to be a major factor for liver cirrhosis and hepatocellular carcinoma. In contrast to the wealth of knowledge on the gene structure and expressional regulation, immunological and pathological mechanisms for HBV-induced hepatocellular injury are not well known. In the present study, vaccinia virus which has been demonstrated to be a useful eukaryotic expression vector was used to clone the gene for HBV surface antigen, L(S+preS2+preS1). The recombinant vaccinia virus vector, pMJ-L, which contains L surface antigen gene of adr-type HBV was constructed, and subseouently used for making recombinant vaccinia virus VV-$\textrm{HBV}_{L}$. Expression of the HBV antigen was examined by immunofluorescent antibody (IFA) test using mouse monoclonal anti-hepatitis B surface antigen. HBsAg was detected in the recombinant virus indicating that the VV-$\textrm{HBV}_{L}$ expressed S antigen successfully. The HBV-Vaccinia Virus recombinant obtained in this study is currently being used for studying the immunological aspects of HBV infection.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.1
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• pp.172-180
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• 2005

Dynamic slicing method decomposes a program into slices and supports to be understood programs easily by software developer or maintainer. In this paper, we propose dynamic slicing algorithm to reduce time to decompose a program. We produce reference-variable set used in right and modify-variable set used in left on the basis of the assignment operator of all sentences and extract Inter-Variable Relationship(VV) for all variables of variable declaration. Proposed algorithm extracts dynamic slices by using them and execution trace of program. In conclusion, proposed algorithm improved the performance by reducing the time to extract dynamic slices by decreasing average comparison count of sentence when the number of criterion variables is three or more.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.3
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• pp.158-168
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• 2015

To create an ultra-high vacuum state at the KSTAR, the temperature of plasma facing component and vacuum vessel should be maintained at $300^{\circ}C$ and $110^{\circ}C$ respectively at a baking phase. The purpose of this research is obtaining the target baking temperatures. Experiments were performed to investigate the temperature characteristics of PFC and VV at the baking phase. Thermal network analysis was used to find heat transfer rates among PFC, VV and other components, and this analysis was verified by using the experimental data. The required heating energy of the PFC and the heating and cooling energy of the VV for the target baking temperatures were found to be 346 kW, 28 kW, and 136 kW, respectively.

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.4
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• pp.249-256
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• 2007

This experiment was conducted to compare the agronomic characteristics and productivity in introduced hairy vetch cultivars and developed new Korean Hairy vetch cultivars in two areas of the experimental field of Grassland and Forage Crops Division, National Institute of Animal Science from 2005 to 2006. The experiment was arranged in randomized complete block design with three replications. A total of 11 hairy vetch cultivars used in this study including 9 introduced cultivars (Penn-02, Sander, Latigo, Welta, Ostsaat, VV4712, Minnie, Barlosa and Capello) and 2 Korean cultivars (Cold green and Cheong pa). The early flowering varieties of Minnie, Barlosa, Capello and Cold green were grown as early maturity cultivars, while the late flowering varieties of Penn-02, Sander, Latigo, Welta, Ostsaat, VV4712 and Cheong pa were grown as medium and late maturity. The winter hardiness of hairy vetch was good except for Minnie, Barlosa and Capello of early maturity cultivars. In this study, dry matter yield of VV4712 was the highest of 11 hairy vetch cultivars. And dry matter yield of medium and late maturity vetch increased in the middle region while that of early maturity increased in the south. The new Korean cultivar, Cheong pa, as a medium and late maturity hairy vetch was not bad compared to introduced cultivars and Cold green as an early maturity hairy vetch was an excellent cultivar compared to introduced cultivars in both regions. Latigo in NDF (neutral detergent fiber) and Welta in ADF (acid detergent fiber) were lower than other cultivars, while Sander in IVDMD (in vitro dry matter digestibility) and CP (crude protein) content were higher than other cultivars. The results of this experiment indicated that the productivity of hairy vetch cultivars was highest in VV4712, and Cheong pa and Cold green of new Korean cultivar were the promising cultivars of hairy vetch in Korea.