• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.19 no.4
• /
• pp.484-491
• /
• 2008

In this paper, we design and fabricate the L-band high speed pulsed HPA using LDMOS FET. And we propose the high voltage and high speed switching circuit for LDMOS FET. The pulsed HPA using LDMOS FET is simpler than using GaAs FET because it has a high gain, high output power and sin81e voltage supply. LDMOS FET is suitable for pulsed HPA using switching method because it has $2{\sim}3$ times higher maximum drain-source voltage(65 V) than operating drain-source voltage($V_{ds}=26{\sim}28\;V$). As results of test, the output peak power is 100 W at 1.2 GHz, the rise/fall time of output RF pulse are 28.1 ns/26.6 ns at 2 us pulse width with 40 kHz PRF, respectively.

• Advances in pediatric surgery
• /
• v.8 no.1
• /
• pp.16-22
• /
• 2002

Between March 1999 and January 2000, 82 boys with the diagnosis of inguinal hernias (12 bilateral and 70 unilateral hernias), underwent Ultrasound (US) examination of both sides of the groin, a total of 164 inguinal imaging prior to surgery. The patients ages ranged from 3 days to 12 years with a mean of 32.6 months. Ninty four examinations were on the clinically symptomatic side and 70 were on the asymptomatic side. The US criteria for the diagnosis of an inguinal hernia were as follows: 1) visceral hernia, the presence of bowel loops, or omentum in the inguinal canal, 2) communicating hydrocele, the presence of fluid in the processus vaginalis, 3) widening of patent processus vaginalis at the level of internal inguinal ring. The width of patent processus vaginalis at the level of internal inguinal ring over 4 mm is considered an occult hernia. Among the 94 symptomatic groins, US findings showed 31 (33%) visceral hernias, 18 (19%) communicating hydroceles, and 38 (41%) widening of the internal inguinal ring, and 7 (7%) groins without abnormalities. In 70 asymptomatic groins, there were 4 (6%) visceral hernias, 5 (7%) communicating hydroceles, 11 (16%) widening of the internal inguinal ring, and 50 (70%) groins without abnormalities. Among the 70 asymptomatic groins there were US abnormalities in 20 (28%). One hundred and seven groins with positive US findings were surgically explored. Among 107 operated sites, the operative findings were compatible with the US diagnosis in 104, a sensitivity for US of 97.2%. In patients with US findings of widening of internal inguinal ring (>4 mm), there was patent processus vaginalis in 36 out of 38 symptomatic groins and 10 of 11 asymptomatic groins. The sensitivity of US to the operative findings in widening of internal inguinal ring was 93.8%. For visceral hernia and communicating hydrocele, the sensitivity of positive US findings was 100%. Ultrasonography for inguinal hernias appears to be a rapid, reliable, and noninvasive screening diagnostic tool with high positive specificity. Therefore, we recommend the use of US as a routine diagnostic tool in pediatric patients with inguinal hernias and hydroceles.

• Journal of Navigation and Port Research
• /
• v.28 no.8
• /
• pp.753-757
• /
• 2004

The free-surface flow is simulated to make clear the viscous interaction of stem waves and the sub-breaking phenomena around a high speed vehicle. The Navier-Stokes equation is solved by a finite difference method where the body-fitted coordinate system, the wall function and the triple-grid system are invoked They are applied to study precisely on the stem flow of S-103 as to which extensive experimental data are available. Computations are extended to the submerged revolutional body. The numerical result shows that the gradient of M/Us is greatly influenced by the submerged depth And the stem wave is influenced by the separation due to the bow wave.

• Communications for Statistical Applications and Methods
• /
• v.28 no.2
• /
• pp.119-134
• /
• 2021

Lung cancer is one of the leading causes of cancer deaths in the world. Investigation of mortality rates is pivotal to adequately understand the determinants causing this disease, allocate public health resources, and apply different control measures. Our study aims to analyze and forecast age-specific US lung cancer mortality trends. We report functions of mortality rates for different age groups by incorporating functional principal component analysis to understand the underlying mortality trend with respect to time. The mortality rates of lung cancer have been higher in men than in women. These rates have been decreasing for all age groups since 1990 in men. The same pattern is observed for women since 2000 except for the age group 85 and above. No significant changes in mortality rates in lower age groups have been reported for both gender. Lung cancer mortality rates for males are relatively higher than females. Ten-year predictions of mortality rates depict a continuous decline for both gender with no apparent change for lower age groups (below 40).

• Journal of the Korea Society for Simulation
• /
• v.28 no.1
• /
• pp.99-107
• /
• 2019

Until now it has had the limitation of the target in the US JMEM to calculate the Pk with the existing method by our study. In this study, we focused on deriving a method to calculate the Pk of the actual targets except JMEM targets using ANN. We study the initial predictive model of ANN(Artificial Neural Network) from the targets data of the specification and the vulnerable area in the US JMEM(Joint Munitions Effectiveness Manuals), and calculate the actual targets vulnerable area by using this method. Finally, we propose a method to calculate the Pk by applying those data to the existing method of us.

• Childhood Kidney Diseases
• /
• v.6 no.1
• /
• pp.68-74
• /
• 2002

Purpose: Suprapubic bladder aspiration(SBA) of urine is the most reliable method to obtain urine avoiding contamination in non-toilet trained infants. Ultrasonography is a useful tool for guiding the anatomic location as well as for direct visualization during procedure. We evaluated the success rate and complication of ultrasound(US) assisted SBA Methods. Sixty infants who visited Ewha Womans University Mokdong Hospital, with suspected urinary tract infection were randomly divided into the US assisted (n=32) and blind SBA(control, n=28) group. In US assisted SBA group, the anteroposterior(AP), transverse, and sagittal diameters and the volume of the bladder were measured. In the blind SBA group, urine was blindly aspirated when the urinary bladder was palpated at the suprapubic area. The rate of successful urine aspiration, the number of attempts until successful aspiration, aspirated urine volume were compared between the two groups. Results: The success rate was $100\%$(32/32) in the US assisted group, which was significantly higher than $85.7\%$(24/28) of the control group (P<0.05). The aspirated urine volume in the US assisted group was $7.4{\pm}3.7\;mL$, which was significantly higher than $4.5{\pm}3.4\;mL$ of the control group (P<0.05), The diameters and volume of bladder in successful aspiration were $2.1{\pm}0.7\;cm$ in AP diameter, $3.1{\pm}0.6\;cm$ in transverse diameter, $4.2{\pm}1.0\;cm$ in sagittal diameter and $15.2{\pm}10.4\;mL$ in volume, which were significantly higher than those ($1.7{\pm}0.3\;cm,\;1.7{\pm}0.3\;cm,\;1.8{\pm}0.7\;cm,\;2.4{\pm]0.6\;cm,\;3.9{\pm}2.5$) of the control group (P<0.05) The correlations between the AP(r=0.78), transverse (r=0.72), sagittal(r=0.91) diameter and bladder volume were significant (P<0.05). SBA was $100\%$ successful in the AP diameter >3 cm, transverse diameter >4 cm, depth >4 cm and bladder volume >5 mL. Conclusion: US assistance can significantly improve the success rate of SBA in infant with suspected urinary tract infection. (J Korean Soc Pediatr Nephrol 2002 ; 6 : 68-74)

• Journal of Distribution Science
• /
• v.14 no.11
• /
• pp.29-36
• /
• 2016

Purpose - Intense debate is occurring over support for farmers in Korea, specifically on the justification, policy design, and equality issues of the farm support programs. Given this debate, a new type of farm program in the US, a market flexible revenue program(the Average Crop Revenue Election, ACRE), is examined. ACRE stands in contrast to traditional programs that tie payments to price and have parameters that are fixed or change only infrequently. Research design, data, and methodology - Based on the ACRE program formulas, the potential payments are estimated by crop year, program crop and geographical area using the FSA acreage and payment rate data. Results - If all US farm program acres were in ACRE over the 2009-2013 crop years, payments would have totaled $7.95 billion or 1.2 percent of average market receipts for US crops. Enacting ACRE as a revenue program instead of a similarly-structured price-only program increased payments by $1.75 billion or 28 percent. Conclusions - Potential payments by ACRE largely reflected the distribution of the value of production across the program crops eligible for ACRE as well as across state geographical areas. If program parameters can be made acceptable and if data availability issues can be addressed, market flexible revenue programs offer a farm policy option that can address many of the concerns that have arisen over farm policy in Korea.

• Journal of Microbiology and Biotechnology
• /
• v.28 no.4
• /
• pp.503-509
• /
• 2018

Endive is widely consumed in a fresh-cut form owing to its rich nutritional content. However, fresh-cut vegetables are susceptible to contamination by pathogenic bacteria. This study investigated the antibacterial activities of the combined treatment of cinnamon leaf oil emulsion containing cetylpyridinium chloride or benzalkonium chloride (CLC and CLB, respectively) as a cationic surfactant and ultrasound (US) against Listeria monocytogenes and Escherichia coli O157:H7 on endive. The combined treatment of CLC or CLB with US reduced the population of L. monocytogenes by 1.58 and 1.47 log colony forming units (CFU)/g, respectively, and that of E. coli O157:H7 by 1.60 and 1.46 log CFU/g, respectively, as compared with water washing treatment. The reduction levels of both pathogens were higher than those observed with 0.2 mg/ml sodium hypochlorite. In addition, the combined treatment showed no effect on the quality of the fresh-cut endive (FCE). In particular, the degree of browning in FCE was less for the treatment group than for the control and water washing treatment groups. Thus, cationic surfactant-based cinnamon leaf oil emulsions combined with US may be an effective washing treatment for the microbial safety of FCE.

• Archives of Plastic Surgery
• /
• v.34 no.2
• /
• pp.181-185
• /
• 2007

Purpose: Cleft lip and/or palate is the most common congenital facial anomaly whose incidence is about 1 in 500~1000 live births. As this anomaly may be associated with the serious chromosomal anomalies or the multiple organ abnormalities resulting in the fetal loss or perinatal maternal morbidity and mortality, careful prenatal counseling with early and accurate detection is important. Although conventional prenatal ultrasound(US) examination in midterm pregnancy has been applied for screening of cleft lip, there are definite limitations in the diagnosis of accompanying cleft palate or alveolar cleft. We applied high-resolution 3D US along the serial axial, coronal and sagittal plane so that we could diagnose the cleft palate and/or alveolar cleft in fetuses with cleft lip. Methods: From May 2005 to September 2005, 20 fetuses with cleft lip were examined with prenatal 3D US. Average maternal age was 28.8 years old(24-35 years old), and average gestational age was 24.8 weeks(17.6 to 34.2 weeks). Consecutive axial, coronal and sagittal multislice view were obtained via prenatal 3D US examination and diagnosis of cleft palate and/or alveolar cleft in cleft lip fetuses was followed. Results: With noninvasive and safe prenatal 3D US examination, 17 of 20 cleft lip fetuses were demonstrated to have cleft palate and/or alveolar cleft. Prenatal counseling according to the result was made. Conclusion: Existing prenatal US examination is suitable for screening the cleft lip fetuses but has limitation in identifying the related existence of cleft palate and/ or alveolar cleft. Authors verify the presence of cleft palate and/or alveolar cleft acquiring the successive multislice axial, coronal, and sagittal view with prenatal 3D US examination. Therefore, prenatal 3D US examination could be regarded as a noninvasive and secure screening modality in fetuses with cleft lip for confirming whether cleft palate and/or alveolar cleft is accompanied.

• Journal of the Korean Chemical Society
• /
• v.39 no.2
• /
• pp.28-81
• /
• 1995

Inductively coupled plasma atomic emission spectrometry was used for the determination of all 14 rare earth elements (REE) in geological materials. Samples were decomposed by using acid digestion followed by alkaline fusion. Group separation of the REE was achieved by solvent extraction with TOPO (trioctylphosphine oxide) and back extraction into HCl. The results for standard rock sample, AGV-1, showed a good agreement with those obtained by US Geological Survey as well as reported values in other articles.