• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.738-740
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• 2003

A lot of R&D on the diagnosis of stator winding insulation for large rotating machines has been carried out since the 1970s. The on-line partial discharge measurement has proved to be an effective technique in the evaluation of the state of stator insulation in high voltage rotating machines. It is well known that if the discharge pulses propagate through the winding conductor, they are attenuated and delayed. In the present study, to investigate the attenuation and the time delay of discharge pulses through the winding conductor, a series of tests were conducted using a model coils and slot. Thus it could be concluded that while the high frequency pulse propagates in radiation or end-winding coupling modes, the low frequency one does in a series mode through the coil conductor.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.5 no.1
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• pp.73-78
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• 2002

Gastroparesis is rare in children and is defined as delayed emptying of gastric contents into the duodenum without mechanical obstruction. We experienced a case of gastroparesis in a 7-year-old boy after a viral illness. He was admitted because of excessive abdominal bloating and diffuse abdominal pain, and was diagnosed by clinical manifestations and measurement of the gastric emtpyting time. He recovered after dietary management and with commbined medication of erythromycin and domperidone in 50 days of illness.

• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.518-530
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• 2020

The present study concerns the stern slamming load of container carriers, with stern bulb arrangement variation. First, a series of wedge drop tests were conducted using simple wedge models with fixed deadrise angles, and tests with the cross-section models of practical container carrier sterns were followed. The deadrise angle of the simple wedge ranged from 0° to 10°. The pressure measurement results of the simple wedge drop tests were distributed between empirical formula and analytic solution, so the experimental setup was validated. In the cases of practical hull cross-sections, the water entry of the bulb prior to that of the transom resulted in characteristic water film generation and delayed pressure peak appearance. The trapped air between the bulbs damped the pressure in the twin skeg hull case, reducing the pressure peak and causing the pressure oscillation during water entry.

• Advances in aircraft and spacecraft science
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• v.8 no.1
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• pp.69-85
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• 2021

A modified fuzzy mechanical control of large-scale multiple time delayed dynamic systems in states is considered in this paper. To do this, at the first level, a two-step strategy is proposed to divide a large system into several interconnected subsystems. As a modified fuzzy control command, the next was received as feedback theory based on the energetic function and the LMI optimal stability criteria which allow researchers to solve this problem and have the whole system in asymptotically stability. Modeling the Fisher equation and the temperature gauge for high-speed aircraft and spacecraft shows that the calculation method is efficient.

• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.2
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• pp.115-124
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• 2015

A methodology is proposed to estimate a trajectory of a flying target and its velocity using the time and frequency analysis of the acoustic signal. The measurement of sound emitted from a flying acoustic source with a microphone above a ground shall receive both direct and ground-reflected sound waves. For certain frequency contents, the destructive interference happens in received signal waveform reflected path lengths are in multiple integers of direct path length. This phenomenon is referred to as the acoustical mirror effect and it can be observed in a spectrogram plot. The spectrogram of acoustic measurement for a flying vehicle measurement shows several orders of destructive interference curves. The first or second order of curve is used to find the best approximate path by using nonlinear least-square method. Simulated acoustic signal is generated for the condition of known geometric of a sensor and a source in flight. The estimation based on cepstrogram analysis provides more accurate estimate than spectrogram.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.3_1spc
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• pp.537-543
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• 2013

A water-$Al_2O_3$ nanofluid was manufactured, and its thermal conductivity was measured in this study. The measurement was performed at volumetric concentrations of 0.5%, 1%, 2%, and 3%, and the nanoparticle sizes were 20 nm and 70 nm. Experimental test equipment, using the transient hot wire method, was installed to measure the thermal conductivity of the nanofluid, and the measured results were confirmed by measuring pure water with a measurement error of 0.92% at $20^{\circ}C$. The thermal conductivity enhancement ranged from 4.8% to 13.6% for the 20 nm particle size, and from 3.1% to 8.8% for the 70 nm particle size at a concentration range of 0.5% to 3%. The enhancement increased with a decrease in particle size and an increase in concentration. With the elapse of time after manufacturing the nanofluid, the thermal conductivity enhancement decreased significantly from 5 to 9 h, and this trend was measured under all of the measurement conditions. After 24 h, the enhancement ranged from 1.2% to 3.5% for the 20 nm particles, and from 0.6% to 2.3% for the 70 nm particles. The enhancement trends with the elapse of time were almost identical with and without stirring the nanofluid. SDBS (Sodium Dodecyl Benzene Sulfonate) was added as a dispersing agent, and the decrease in the thermal conductivity enhancement was delayed.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.23-23
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• 2017

Rice (Oryza sativa L.) is the world's most important cereal crop. In crop plant, chlorophyll content and leaf senescence could affect grain filling and yield. We analyzed a QTL associated with chlorophyll content and delayed leaf senescence using high chlorophyll near isogenic line (HC-NIL). HC-NIL derived from a cross between Oryza sativa cv. Hwaseong as a recurrent parent and wild species O. grandiglumis as a donor parent showed higher chlorophyll content than Hwaseong. To identify QTL associated with chlorophyll content, 58 $F_3$ and 38 $F_4$ lines were developed from a cross between HC-NIL and Hwaseong. For QTL analysis, simple sequence repeat (SSR) markers were used for genotyping and one-way ANOVA was conducted. A QTL for chlorophyll content (qCC2) was detected in chromosome 2 and explained 24.63% of phenotypic variation. The senescence effect of the qCC2 was examined in dark-induced incubation (DII). Detached leaves from Hwaseong and HC-NIL were incubated on 3mM MES buffer (pH 5.8) at $27^{\circ}C$ under complete dark condition. After 3 days of incubation, the Hwaseong leaves turned yellow, but the HC-NIL leaves were green. HC-NIL has higher chlorophyll content with delayed senescence than Hwaseong. These results indicated that qCC2 is associated with stay-green phenotype. To know whether the qCC2 is responsible for leaf functionality, ion leakage test and Fv/Fm measurement were performed. Both experiment results showed that differences were observed between Hwaseong and HC-NIL but it was not statistically significant. These results might suggest that the qCC2 is possibly related to chlorophyll content and non-functional stay-green phenotype.

• Obstetrics & gynecology science
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• v.61 no.6
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• pp.655-661
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• 2018

Objective There is concern regarding the safety of delayed cord clamping (DCC) in babies born at less than 34 weeks' gestation. Therefore, the primary objective of this study was to compare the rates of hyperbilirubinemia and polycythemia during initial 7 days in infants born at less than 34 weeks' gestation and randomized to receive DCC by 120 seconds or early cord clamping (ECC) within less than 30 seconds. Methods One hundred pregnant women were randomly subjected to DCC or ECC at the time of birth in a tertiary referral hospital setting. Blood samples were obtained from each newborn at 48 hours and 7 days for hematocrit measurement. Serum bilirubin levels were estimated once the infant had clinically significant jaundice or at 72 hours. For the statistical analysis, the ${\chi}^2$ test, Student's t-test, or Wilcoxon rank sum test was used. Results The hematocrit was significantly higher in the DCC group than in the ECC group (P<0.001). None of the babies had polycythemia. Mean total serum bilirubin level was 6.6 mg/dL in the DCC group and 8.7 mg/dL in the ECC group (P<0.001). There was no increased risk of hyperbilirubinemia in the DCC group. Conclusion DCC benefits preterm neonates with no significant adverse effects.

• Tunnel and Underground Space
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• v.24 no.1
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• pp.67-80
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• 2014

Long-term stability and delayed failure of granite were evaluated through the laboratory test based on Wilkins method and Brazilian disc test (BDT) which yields tensile strength, mode I fracture toughness and subcritical crack growth parameters. Then, the long-term strength of granite was estimated by using analytical models and long-term stability of compressed air-energy storage (CAES) pilot cavern pressurized up to 5 ~ 6 MPa was evaluated using numerical code, FRACOD with the determined subcritical crack growth parameters. The results of test and analyses showed that the subcritical crack growth index, n was determined as 29.39 and the inner pressure of 5 ~ 6 MPa had an insignificant effect on the long-term stability of pilot cavern. It was also found that the measurement and analysis of acoustic emission events can describe the accumulation of damage due to subcritical crack growth quantitatively. That is, AE monitoring can provide the current status of rock under loading if we make an identical installation condition in the field with that of the laboratory test.

• Korean Journal of Adult Nursing
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• v.21 no.6
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• pp.559-569
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• 2009

Purpose: This study was to examine the reliability and validity of Patient-Generated Subjective Global Assessment (PG-SGA) as a nutritional measurement for stroke patients. Methods: This was a methodological study performed from May 6 to June 10, 2009 at a tertiary university hospital in Seoul. For reliability of PG-SGA, inter-rater reliability was used for statistics. For concurrent validity, BMI and biomarkers were compared between PG-SGA 0 ~ 8 and ${\geq}$ 9. In addition, sensitivity, specificity, and predictive value of PG-SGA compared with SGA were calculated using a contingency table. For predictive validity, hospital day, complications, and readmission within 1-month after discharge were compared between PG-SGA 0 ~ 8 and ${\geq}$ 9. Results: Correlation of PG-SGA score between two observers was 0.83, and kappa value for the agreement of severe malnutrition was 0.78(all $p_s$ < .001). The scored PG-SGA showed high sensitivity and specificity (100% and 96.7%, respectively). Severe undernourished patients (PG-SGA ${\geq}$ 9) had significantly low TLC, protein, albumin, and prealbumin (all $p_s$ < .01) compared with non-undernourished patients (PG-SGA 0 ~ 8). Also, in severe undernourished patients, complications and readmission (all $p_s$ = 0.01) were more often represented, and hospital days (p = .013) were significantly delayed. Conclusion: PG-SGA is a reliable and valid measurement to assess nutritional status for stroke patients.