• Journal of Chest Surgery
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• v.13 no.4
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• pp.364-374
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• 1980

Twenty-two patients were selected for evaluation of pre-and postoperative pulmonary function. These patients were performed open cardiac surgery with the extracorporeal circulation from March 1979 to July 1980 at the Department of Thoracic and Cardiovascular Surgery, Kyungbook National University Hospital. Patients were classified with ventricular septal defect 5 cases, atrial septal defect 5 cases, tetralogy of Fallot 5 cases, mitral stenosis 4 cases, rupture of aneurysm of sinus Valsalva 1 case, left atrial myxoma I case, and aortic insufficiency 1 case. The pulmonary function tests were performed and listed: [1] respiratory rate, tidal volume [TV], and minute volume[MV], [2] forced vital capacity [FVC] and forced expiratory volume[FEV 0.5 & FEV 1.0], [3] forced expiratory flow [FEF 200-1200 ml & FEF 25-75%]. [4] Maximal voluntary ventilation [MVV], [5] residual volume [RV] and functional residual capacity[FRC], measured by a helium dilution technique. Respiratory rate increased during the early postoperative days and tidal volume decreased significantly. These values returned to the preoperative levels after postoperative 5-6 days. Minute volume decreased slightly, but essentially unchanged. Preoperative mean values of the forced vital capacity, functional residual capacity and total lung capacity decreased [63.2%, 87.2% & 77.3% predicted, respectively], and early postoperatively these values decreased further [19.6%, 76.0% & 38.0% predicted], but later progressively increased to the preoperative levels. In residual volume, there was no decline in the preoperative mean values [100.9% predicted] and postoperatively the value rather increased [106.3-161.7% predicted]. Forced expiratory volume [FEV 0.5 & FEV 1.0] and forced expiratory flow [FEF 200-1200 ml & FEF 25-75%] also revealed significant declines in the early postoperative period. There was no significant difference in values of the spirometric pulmonary function tests, such as FEF 1.O and FEF 25-75% between successful weaning group [17 cases] extubated within 24 hrs post-operatively and unsuccessful weaning group [5 cases] extubated beyond 24 hrs. Static compliance and airway resistance measured for the two cases during assisted ventilation, however, any information was not obtained. Long term follow-up pulmonary function studies were carried out for 8 cases in 9 months post-operatively. All of the results returned to the pre-operative or to normal predicted levels except FVC, FEV 1.0, and FEF 25-75% those showed minimal declines compared to the pre-operative figures.

• The Journal of the Korean Society for Microbiology
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• v.20 no.1
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• pp.65-72
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• 1985

Vitamin C is known as an integral element for the formation and maintenance of intercellular supporting structures. Ascorbic acid has been used for the treatment of certain poisonings and hypovitaminosis(scurvy) but also known as a powerful reducing agent, and can kill a variety of bacteria and detoxify bacterial exotoxins including various clostridial exotoxins in vitro. For viruses, vitamin C inactivates herpes virus, vaccinia virus and influenza virus and has been used for the prevention and treatment of the common cold. Thus ascorbic acid plays an important role in antimicrobial action. Scurvy also promotes the development of tubercles in experimentally infected guinea pig and the tuberculosis patients require more vitamin C than normal persons. However there is no reports that ascorbic acid could inhibit the growh of M. tuberculosis. In this paper, antibacterial effects of ascorbic acid against M. tuberculosis were studied. The results are as follows: 1. The single use of the ascorbic acid exhibited antibacterial effect in vitro against $5{\times}10^3/ml$ of M. tuberculosis $H_{37}$ Rv at the concentration of ascorbic acid 0.625mg/ml over 3 hours exposure and 0.05mg/ml over 9 hours exposure. 2. In vivo mice administered with ascorbic acid 50mg/day for 5, 10 and 15 days respectively were protected from M. tuberculosis $2LD_{50}$, $3LD_{50}$, $4LD_{50}$ and $5LD_{50}$ given intravenously.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.53.1-53.1
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• 2015

The GMT-Consortium Large Earth Finder(G-CLEF) is one of the first light instruments at the Giant Magellan Telescope. The international consortium consists of five astronomical institutes including the Center for Astrophysics, the Observatories of Carnegie Institute, the University of Catolica in Chile, the University of Chicago, and Korea Astronomy and Space Science Institute, led by CfA. The extremely precise radial velocity capability is one of the principal instrumental feature of G-CLEF. The RV goal is 10 cm/s capable of detecting an Earth-like planet around a Sun-like host star. This high precision wavelength calibration stability requires a set of significantly tight optomechanical tolerances in the mechanical design of the Flexure Control Camera system. KASI is in charge of the Flexure Control Camera and the Calibration Light System for the G-CLEF spectrograph. In this presentation, we introduce the preliminary design and analysis results of the G-CLEF Flexure Control Camera.

• Journal of the Korean Chemical Society
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• v.56 no.2
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• pp.236-245
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• 2012

The main mycobacterial infection in human is tuberculosis caused by Mycobacterium tuberculosis. Tuberculosis is the leading infectious cause of death in the world. Therefore there is continuing and compelling need for new and improved treatment for tuberculosis. The entire logic towards design of new compounds containing 4-hydroxy-N'-(1,3-thiazoldin- 2-yldene)benzohydrazide moiety is basically for superior antimycobacterial activity. The recent advances in QSAR and computer science have provided a systematic approach to design a structure of any compound and further, the biological activity of the compound can be predicted before synthesis. The 3D-QSAR studies for the set of 4-hydroxy-N'-(1,3-thiazoldin- 2-yldene)benzohydrazide and their derivatives were carried out by using V-life MDS (3.50). The various statistical methods such as Multiple Linear Regression (MLR), Partial Least Square Regression (PLSR), Principle Component Regression(PCR) and K nearest neighbour (kNN) were used. The kNN showed good results having cross validated $r^2$ 0.9319, $r^2$ for external test set 0.8561 and standard error of estimate 0.2195. The docking studies were carried out by using Schrodinger GLIDE module which resulted in good docking score in comparison with the standard isoniazid. The designed compounds were further subjected for synthesis and biological evaluation. Antitubercular evaluation of these compounds showed that (4.a), (4.d) and (4.g) found as potent inhibitor of H37RV.

• Journal of Microbiology and Biotechnology
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• v.25 no.5
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• pp.745-752
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• 2015

Tuberculosis (TB) is the most common mycobacterial infection in developing countries, requiring a rapid, accurate, and well-differentiated detection/diagnosis. For the rapid detection and discrimination of Mycobacterium tuberculosis complex (MTC) from non-tuberculous mycobacteria (NTM), a novel, simple, and primer-combined single-step multiplex PCR using three primer pairs (6110F-6110R, 1081F-1081R, and 23SF-23SR; annealing on each of IS6110, IS1081, and 23S rDNA targets), hereafter referred to as a triplex PCR, has been developed and evaluated. The expected product for IS6110 is 416 bp, for IS1081 is 300 bp, and for 23S rDNA is 206 bp by single PCR, which was used to verify the specificity of primers and the identity of MTC using DNA extracted from the M. tuberculosis H37Rv reference strain (ATCC, USA) and other mycobacteria other than tuberculosis (MOTT) templates. The triplex PCR assay showed 100% specificity and 96% sensitivity; the limit of detection for mycobacteria was ~100 fg; and it failed to amplify any target from DNA of MOTT (50 samples tested). Of 307 blinded clinical samples, overall 205 positive M. tuberculosis samples were detected by single PCR, 142 by conventional culture, and 90 by AFB smear methods. Remarkably, the triplex PCR could subsequently detect 55 positive M. tuberculosis from 165 culture-negative and 115 from 217 AFB smear-negative samples. The triplex PCR, targeting three regions in the M. tuberculosis genome, has proved to be an efficient tool for increasing positive detection/discrimination of this bacterium from clinical samples.

• Nuclear Engineering and Technology
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• v.49 no.7
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• pp.1524-1536
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• 2017

During the fabrication process of reactor vessel head penetration (RVHP), the grain size of the tube material can be changed by hot or cold work and the inner side of the tube can also be shrunk due to welding outside of the tube. Several nonregular time-of-flight diffraction (TOFD) signals were found because of deformed grains. In this paper, an investigation of nonregular TOFD indications acquired from RVHP tubes using experiments and computer simulation was performed in order to identify and distinguish TOFD signals by coarse grains from those by Primary Water Stress Corrosion Crack (PWSCC). For proper understanding of the nonregular TOFD indications, microstructural analysis of the RVHP tubes and prediction of signals scattered from the grains using Finite Element Method (FEM) simulation were performed. Prediction of ultrasonic signals from the various sizes of side drilled holes to find equivalent flaws, determination of the size of the nonregular TOFD indications from the coarse grains, and experimental investigation of TOFD signals from coarse grain and shrinkage geometry to identify PWSCC signals were performed. From the computer simulation and experimental investigation results, it was possible to obtain the nonregular TOFD indications from the coarse grains in the alloy 690 penetration tube of RVHP; these nonregular indications may be classified as PWSCC. By comparing the computer simulation and experimental results, we were able to confirm a clear difference between the coarse grain signal and the PWSCC signal.

• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 2001.12a
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• pp.126-126
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• 2001

The Rhus verniciflua contains alkly(en)-catechol type allergens with a saiurated or unsaturated alkly chain of 15 or 17 carbon atoms. It has been recognized as an extremely active allergen causing skin reactions similar In poison ivy. The allergic contact dermatitis induced by the urushiol is known to be mediated be T lymphocytes whicht specifically recognize the hepten urushiol. Therefore. direct use of this plant as a medicinal purpose might imply a considerable hazard in Korea. In this study, using the established method for the detoxification from the stem bark of Rhus verniciflua, an strong antioxidant substance was isolated and characterized DPPH (diphenypricryl hydrazyl) assay measures hydrogen atom-donating activity and hence provides a measure of free radical scavenging antioxidant activity. DPPH, a purple-colored stable free radical, is reduced to yellow-colored diphenylpicryl hydrazine by antioxidants to deducing agents. Antioxidative effects of the water extract from RV were measured by DPPH assay. Twenty microliters of the extract was added to 1ml of 100mM DPPH solution in ethanol The mixture was shaken and left to stand for 10min at room temperature. The crude water extracts was purified by using HPLC method with a DEAE (anionic type), CN, ODS column. The purified compound remained stable at pH 3.0-6,0, but unstable above pH 6.5. It was stable heat at 10$0^{\circ}C$ for 4 hours, but still had about 80% of residual activity after treatment at 10$0^{\circ}C$ for 5 hours. The elemental composition of the HR-EI mass spectrum at m/z 170.02 was estimated the empirical formula as $C_{7}$ $H_{6}$ $O_{5}$. $C_{10}$ $H_4$ $O_2$N$_1$, $C_{5}$ $H_4$ $O_4$N$_3$, $C_{8}$$H_2O$$_1$N$_4$. In antimicrobial test, no inhibition was observed against Gram-positive and negative bacteria. This compound was stronger than that of commercial antioxidant by DPPH test, such as BHT, BHC at the same concentration (20$\mu$g/ml).ml).

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.7
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• pp.918-924
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• 2013

In a conventional power system, the frequency is recovered to the nominal value by the inertial, primary, and secondary responses of the synchronous generators (SGs) after a large disturbance such as a generator tripping. For a power system with high wind penetration, the system inertia is significantly reduced due to the maximum power point tracking control based operation of the variable speed wind generators (WGs). This paper proposes a virtual inertial control for a wind power plant (WPP) based on the maximum rate of change of frequency to release more kinetic energy stored in the WGs. The performance of the proposed algorithm is investigated in a model system, which consists of a doubly fed induction generator-based WPP and SGs using an EMTP-RV simulator. The results indicate that the proposed algorithm can improve the frequency nadir after a generator tripping. In addition, the algorithm can lead the instant of a frequency rebound and help frequency recovery after the frequency rebound.

• Journal of Electrical Engineering and Technology
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• v.11 no.1
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• pp.86-92
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• 2016

Upon detecting a frequency event in a power system, the stepwise inertial control (SIC) of a wind turbine generator (WTG) instantly increases the power output for a preset period so as to arrest the frequency drop. Afterwards, SIC rapidly reduces the WTG output to avert over-deceleration (OD). However, such a rapid output reduction may act as a power deficit in the power system, and thereby cause a second frequency dip. In this paper, a hybrid reference function for the stable SIC of a doubly-fed induction generator is proposed to prevent OD while improving the frequency nadir (FN). To achieve this objective, a reference function is separately defined prior to and after the FN. In order to improve the FN when an event is detected, the reference is instantly increased by a constant and then maintained until the FN. This constant is determined by considering the power margin and available kinetic energy. To prevent OD, the reference decays with the rotor speed after the FN. The performance of the proposed scheme was validated under various wind speed conditions and wind power penetration levels using an EMTP-RV simulator. The results clearly demonstrate that the scheme successfully prevents OD while improving the FN at different wind conditions and wind power penetration levels. Furthermore, the scheme is adaptive to the size of a frequency event.

• Journal of Electrical Engineering and Technology
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• v.10 no.6
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• pp.2221-2227
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• 2015

To arrest a frequency nadir, a stepwise inertial control (SIC) scheme generates a constant active power reference signal of a wind turbine generator (WTG) immediately after a disturbance and maintains it for the predetermined time. From that point, however, the reference of a WTG abruptly decreases to restore the rotor speed for the predefined period. The abrupt decrease of WTG output power will inevitably cause a second frequency dip. In this paper, we propose a modified SIC scheme of a doubly-fed induction generator (DFIG) that can prevent a second frequency dip. A reference value of the modified SIC scheme consists of a reference for the maximum power point tracking control and a constant value. The former is set to be proportional to the cube of the rotor speed; the latter is determined so that the rotor speed does not reach the minimum operating limit by considering the mechanical power curve of a DFIG. The performance of the modified SIC was investigated for a 100 MW aggregated DFIG-based wind power plant under various wind conditions using an EMTP-RV simulator. The results show that the proposed SIC scheme significantly increases the frequency nadir without causing a second frequency dip.