• Journal of the Korean Society of Radiology
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• v.84 no.4
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• pp.923-933
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• 2023

Purpose To evaluate the sensitivity of corticomedullary-phase imaging for detecting urinary stones in patients with renal colic who visited the emergency department. Materials and Methods This retrospective study included 253 patients with suspected renal colic from two tertiary hospitals in South Korea, who visited the emergency department and underwent CT urography. Two radiologists blinded to the clinical history independently reviewed the corticomedullary-phase images. The sensitivity for identifying urinary stones were evaluated for each reviewer. After the initial evaluation, the images were re-evaluated based on patient history. The sensitivity of re-evaluation were recorded. Results Of 253 patients, 150 (59%) had urinary stones. Among them, significant stones were observed in 138 patients (92%), and obstructive changes on CT in 124 patients (82.7%). For identifying significant urinary stones, the sensitivity was 98.6% (136/138) for both the reviewers. For identifying significant urinary stones with urinary obstruction, the sensitivity was 99.2% (123/124) for reviewer 1, and 100% (124/124) for reviewer 2. The sensitivity for identifying significant stones increased from 98.6% to 100% for reviewer 1, and from 98.6% to 99.3% for reviewer 2 in the re-evaluation session. Conclusion The corticomedullary-phase CT urography was sensitive for diagnosing urolithiasis in patients with acute renal colic who visited the emergency department.

• Childhood Kidney Diseases
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• v.5 no.1
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• pp.15-21
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• 2001

Purpose : Urinary tract infections (UTIs) of children require prompt and correct diagnosis and treatment to reduce the risk of renal damage. As a first step to improve the outcome of UTI in Korea, we investigated the practical variations in the methods of diagnosis, treatment, and evaluation of children with UTI and UTI prevention. Method :A questionnaire related to the individual policy on UTI diagnosis. treatment, imaging test, and prevention was submitted to 26 experts. Result Majority of the experts used bag-collected urine specimen for infants and mid-stream urine specimen for children for urinary culture. With a negative result of culture study, they diagnosed UTI when there was pyuria, positive results of the nitrite test, or bacteriuria. 80 $\%$ of experts prescribed prophylactic antibiotics after upper tract UTI. Operative treatment of vesicoureteral reflux (VUR) was indicated for children older than one or two years old with high-grade VUR, refractory breakthrough infections, or recurrent UTIs. Most of them performed kidney ultrasonography on the diagnosis of UTI and more than half of them evaluated children treated of UTI with vesicocystourethrogram and/or DMSA scintigraphy. Majority did not recommend circumcision. Half of the experts were screening siblings of VUR patients. Conclusion : Considering the variations exposed through this study systematic guidelines for management of children with UTI in Korean would be necessary. (J. Korean Soc Pediatr Nephrol 5 : 15-21, 2001)

• The Korean Journal of Applied Statistics
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• v.5 no.2
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• pp.169-179
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• 1992

It is shown that a structurally complete row-column design has orthogonal factorial structure if each of its component designs has orthogonal factorial structure. It implies that such designs are most easily constructed via the amalgamating of one-dimensional block designs which have orthogonal factorial structure. However, this does not always hold for structurally incomplete row-column designs. A structurally incomplete row-column design is derived from the design with adjusted orthogonality, by simply interchanging row and treatment numbers.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.277-280
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• 2006

Using yaw system, Wind turbine can face the wind to make it's electricity generating maximum and to make it's fatigue load minimum. So, in wind turbine design process, selecting optimum yaw system is very important work. In this paper, the yaw moments on yaw bearing, yaw drive and yaw brake were calculated. and From the result, the duty cycle was obtained. At last, using this duty cycle, optimum yaw system is selected.

• Clinical and Experimental Pediatrics
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• v.49 no.3
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• pp.278-286
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• 2006

Purpose : Although suprapubic bladder aspiration(SBA) is the most reliable technique for identifying bacteriuria in young infant, no report has been published about the clinical manifestations of urinary tract infection(UTI) diagnosed by aspirated urine in Korea. This study was performed to examine clinical manifestations and related factors of UTI confirmed by a positive urine culture obtained by SBA in young infants. Methods : We reviewed medical records of 159 infants younger than six months of age, who had been admitted for UTI to Korea University Ansan Hospital from January 2002 to June 2005. Results : The male:female ratio was 5.1 : 1. The most common pathogen in urine culture was Escherichia coli(92.5 percent). Most of the gram-negative pathogens had high sensitivity to amikacin, or third generation cephalosporins and had low sensitivity to ampicillin, trimethoprim-sulfamethoxazole, or gentamicin. Hydronephrosis and vesicoureteral reflux(VUR) were present in 32.7 percent and 27.7 percent respectively. Renal cortical defects observed on DMSA scans were detected in 37.1 percent. Prolonged fever duration and hospital day, high erythrocyte sedimentation rate(ESR) and C-reactive protein(CRP) levels, hydronephrosis and VUR were related to the renal cortical defects(P<0.05). Rates of UTI-associated bacteremia and aseptic meningitis were 8.3 percent and 6.6 percent. Conclusion : Early differential diagnosis is very important in infants younger than 6 months of age with UTI because the clinical findings are non-specific and UTI-associated bacteremia and aseptic meningitis are concomitantly found. Because prolonged fever and higher ESR and CRP levels are risk factors of the renal cortical defects, radiologic evaluations and nephrologic follow-up were needed in identifying the predisposing congenital abnormalities and chronic renal scarring.

• Pediatric Infection and Vaccine
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• v.11 no.1
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• pp.90-100
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• 2004

Objective : Urinary tract infection(UTI) is a frequent serious bacterial infection in young infants. The clinical presentation may be non-specific and variable, depends on factors such as the age and the level of infection. Children with renal involvement may be at risk of permanent renal damage. Experimental studies have shown that renal lesions caused by acute febrile UTI may be prevented or diminished by early diagnosis and treatment. Therefore, it is important to find a method that can permit early diagnosis and identification of patients who are at risk for progressive renal damage. We designed this study to identify related factors in culture positive UTI infants, and also to identify related factors in culture negative UTI infants, who are febrile with pyuria, by using renal imaging and functional studies including renal sonography, DMSA scan and VCUG. Methods : Retrospectively analyzed the medical records of 136 febrile infants with pyuria over 2 years(from January 2001 to February 2003). Urine culture was done in all cases, and regardless of urine culture findings, renal imaging study was done if symptomatic UTI suspected. Results : Total 57 organisms were isolated in 53 patients. E. coli was the most common organism(86%), followed by E. faecalis, M. morganii, Proteus species, P. aeruginosa, S. aureus and E. fergusonii. Most of the isolates had high sensitivity on cephalosporins or amikacin and had low sensitivities on aminopenicillins. Abnormal acute phase DMSA scan or VCUG findings were seen in both urine culture positive and negative group without statistical differences(P>0.05). In febrile infants with pyuria, fever over 48 hours, older age and high CRP related to abnormal acute phase DMSA scan findings regardless urine culture results. Conclusion : 1st or 3rd generation cephalosporins with amikacin could be the first choice of treatment for UTI. Febrile infants with positive urine culture dose mean urinary tract infection but not acute pyelonephritis which directly relates to cortical damage which could be confirmed by acute phase DMSA scan. Even cases with negative urine culture findings, acute pyelonephritis should be concerned in febrile infants with pyuria who are older than 3 months of age, has fever over 48 hours or high CRP level. And in such cases, acute phase DMSA scan and VCUG should be evaluated for early treatment and long term prognosis.

• The Monthly Diabetes
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• s.220
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• pp.36-38
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• 2008

요로감염은 우리에게 조금은 생소하지만 당뇨병으로 인한 감염으로 무시할 수 없는 부분을 차지한다. 당뇨로 인한 방광염의 빈도가 증가하면서 요로감염이 동반될 수도 있기 때문에, 그 심각성과 대처방안 등을 울산대학교병원 감염내과 전재범 교수에게 들어 보았다.

• The Korean Journal of Applied Statistics
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• v.19 no.3
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• pp.587-598
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• 2006

The number of variables exceeds the number of samples in microarray data. We propose a nonparametric local linear logistic classification procedure using orthogonal components for classifying high-dimensional microarray data. The proposed method is based on the local likelihood and can be applied to multi-class classification. We applied the local linear logistic classification method using PCA, PLS, and factor analysis components as new features to Leukemia data and colon data, and compare the performance of the proposed method with the conventional statistical classification procedures. The proposed method outperforms the conventional ones for each component, and PLS has shown best performance when it is embedded in the proposed method among the three orthogonal components.

• Proceedings of the ESK Conference
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• 1997.10a
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• pp.97-105
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• 1997

급속히 변화하는 현대사회에서 생활수준의 향상과 식생활의 서구화 및 신체의 활동량 감소, 과잉 영양공급으로 체중이 증가하여 체형의 변화가 일어난다. 이에 본 연구에서는 체형을 변화시키는 여러 요인 중에서 피하지방으로 인한 변화를 알아보기 위해 초음파 피하지망 계측기를 사용하여 20대 남성을 대상으로 19 .approx. 24세를 집단1, 25 .approx. 28세를 집단2로하여 각 집단간의 피하지방 분포경향과 각 집단간의 피하지방 계측피를 요인분석하여 남성복 의복제작 및 현대남성의 올바른 체형해석을 위한 기초자료 제공이 본 연구의 목적이다. 피하지방이 침착하기 쉬운 부위는 허리앞1/2과 배앞 1/2로 나타 났고, 피하지방이 침착하기 어려운 부위는 하퇴전면으로 나타났다. 피하지방두께 계측에서 집단간 유의 차 검증결과 20대 후반으로 연령이 증가함에 따라 작은 폭으로 지방침착이 일어났다. 집단1의 요인분석 결과 요인1은 허리부위, 요인2는 체간부1/2과 체간부 측면부위로 나타났다. 집단2의 요인분석결과 요인 1은 윗가슴부위와 허리부위, 요인2는 전체적부위로 나타났다. 전체집단에서는 요인분석결과 요인1은 상 지, 하지부위, 요인2는 허리부위로 나타났다. 연령의 증가와 함께 피하지방 침착이 체간부 하부인 허리 와 배를 중심으로 이루어지는 것으로 나타났다.

• Childhood Kidney Diseases
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• v.15 no.1
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• pp.58-65
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• 2011

Purpose: Some hormonal and electrolyte abnormalities have been reported in pediatric patients with urinary tract infection (UTI). This study aimed to investigate the relationships between the imbalance of electrolytes and the severity of infection and associated urologic anomalies in children with febrile UTI. Methods: We retrospectively reviewed 267 patients with febrile UTI who were admitted to Korea University Guro Hospital during the period from January, 2007 until February, 2010. According to the presence of hyponatremia or hyperkalemia, clinical parameters and associated renal anomalies, such as hydronephrosis, cortical defects and vesicoureteral reflux, were compared. Results: 42.7% of all patients had decreased concentration of serum sodium. In patients with decreased concentration of serum sodium, cortical defects were significantly increased compared to normal patients (40.4% vs. 14.4%, P <0.05). White blood cell (WBC) counts ($15,721{\pm}6,553/uL$ vs. $12,885{\pm}5,367/uL$, P <0.05), C-reactive protein (CRP) ($61.8{\pm}56.1$ mg/L, vs. $29.9{\pm}39.8$ mg/L, P <0.05), and erythrocyte sedimentation rate (ESR) ($43.9{\pm}34.3$ mm/hr vs. $27.4{\pm}26.8$ mm/hr, P <0.05) in peripheral blood showed significant increases in the group with decreased concentration of serum sodium. Duration of fever, presence of gastrointestinal symptom, the incidence of hydronephrosis and vesicoureteral reflux did not differ between the two groups. None of the patients had significant hyperkalemia. Conclusion : We suggest that decreased concentration of serum sodium in febrile UTI might be a helpful marker for leukocytosis and increased CRP and ESR in peripheral blood, and acute pyelonephritis.