• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.4
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• pp.306-323
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• 2001

종양발생에서 유전자 발현을 확인하고 profile 변화를 monitor하는 것은 병리학적 변화의 원인뿐 아니라 질병탐지와 진료의 새로운 목표를 확인하기 위한 새로운 기회를 제공해준다. cDNA microarray는 수천개의 유전자 발현을 동시에 연구할 수 있는 최신의 방법으로 피부, 유방, 간을 비롯한 다른 인체장기에서는 일부 이루어졌으나 array를 이용해 타액선 종양 연구에서는 전혀 이루어지지 않았다. 인간의 타액선 세포의 악성형질전환을 조절하는 분자적 상태를 연구하기 위해 본 연구는 약 2,000개의 유전자가 print된 cDNA microarray를 이용하여 인간 타액선 도관상피세포주(HSG)와 악하선에서 기원한 미분화 선암종(SGT)간에 비교연구를 하였다. Cy3와 Cy5 dye로 각각의 세포주에서 얻은 RNA와 reciprocal hybridize시키고 GenePix 4000 scanner로 스캔하고 GenePix Pro로 분석한 후 log2로 평균발현비율을 전환시켜 최소 2배이상의 발현을 보이는 유전자를 분석대상으로 하였다. 90%이상의 유전자가 비슷한 발현을 보였으며 2배이상의 발현을 보이는 경우 HSG가 SGT에 비해 72개 유전자가, SGT가 HSG에 비해 111개의 유전자 발현이 up-regulation되어 총 10%미만의 발현차이를 보였고 반복된 hybridization 으로부터 얻은 선택된 spot의 Pearson 상관계수는 -0.85이였다. HSG에서는 6번 p 염색체에서 과발현되는 유전자가 가장 많았고, SGT에서는 11번 q 염색체에서 가장 많았는데 HSG에서는 SGT에 비해 9, 13, 17, 18, 20, 21, 22염색체에서 과발현 되는 유전자 수가 많았고, SGT에서는 HSG에 비해 2, 7, 10, 15 염색체에서 유전자 발현 증가가 관찰되었다. HSG와 SGT간의 유전 발현을 기능별로 분석한 결과 몇 가지 주요 경로가 세포악성에 관련됨을 발견하였고, 타액선 도관상피세포에서 선암종을 구별하는데 기여하는 관련된 몇종의 과다 발현된 유전자를 찾았는데 전사인자, 성장인자 및 수용기, 세포골격 및 세포외기질 단백, 세포내 신호전달조절자 및 인자, 세포표면 항원등의 그룹으로 분류할 수 있었다. 따라서 이러한 microarray를 이용한 분자학적 표지자 연구가 악성 타액선 종양 발생과정에서 큰 도움을 줄 수 있을 뿐 아니라 유전자 조절에 의한 진단, 예후, 치료에서의 정확성을 개선시킬 수 있으리라 여겨진다.

• Tuberculosis and Respiratory Diseases
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• v.54 no.1
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• pp.5-14
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• 2003

Background : According to the study in ICOPER (International Cooperative Pulmonary Embolism Registry), the overall mortality rate of acute pulmonary thromboembolism (APTE) at 3 months is 17.4%. According to the study for current status of APTE in Japan, the hospital mortality rate is 14%. Although the incidence and mortality rate of APTE has been increasing, patient characteristics, management strategies, and outcome of APTE in the Korean population have not yet been assessed in large series. We therefore performed the national survey for the current status of APTE in the Korean population. Methods : 808 registry patients with APTE were analyzed with respect to clinical characteristics, risk factors, diagnostic procedures, treatment, and clinical outcome. Results : Main risk factors were immobilization, recent major surgery, and cancer. Common symptoms were dyspnea and chest pain. Common signs were tachypnea and tachycardia. The majority of registry patients underwent lung perfusion scanning. Spiral CT was used in 309 patients(42.9%), and angiography in 48 patients(7.9%). Heparin was the most widely used treatment. On multivariate logistic regression analysis, onset in hospital (odds ratio 1.88, p=0.0385), lung cancer (odds ratio 9.20, p=0.0050), tachypnea (odds ratio 3.50, p=0.0001), shock (odds ratio 6.74, p=0.0001), and cyanosis (odds ratio 3.45, p=0.0153) were identified as significant prognostic factors. The overall mortality rate was 16.9% and mortality associated with APTE was 9.0%. Conclusions : The present registry demonstrated the clinical characteristics, diagnostic strategies, management and outcome of patient with APTE in Korea. The mortality rate was 9.0%, and the predictors of mortality were onset in hospital, lung cancer, tachypnea, shock, and cyanosis. These results may be important for risk stratification as well as for the identification of potential candidates for more aggressive treatment.

• Journal of Gastric Cancer
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• v.6 no.4
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• pp.263-269
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• 2006

Purpose: The aim of this study was to investigate the causes of under-staging in patients with advanced gastric cancer that was proven to be unresectable after a laparotomy. Materials and Methods: We retrospectively analyzed 25 gastric cancer patients who had undergone a diagnostic laparotomy between 2001 and 2005. For the preoperative evaluation, spiral CT and multidetector-row CT were performed. We analyzed the clinicopathologic features of patients and compared the image findings and the results of surgery. The causes of under-staging were divided into 3 groups; patient factor, CT factor, and interpretation factor. Results: Grossly, there were 12 cases of Borrmann type-III tumors and 13 cases of Borrmann type-IV tumors. The most frequent histologic type was poorly differentiated adenocarcinomas (8 cases) and signet ring cell carcinomas (7 cases). There were 13 cases of adjacent organ invasion, and the pancreas was the most frequently invaded organ (9 cases). There were 17 cases of peritoneal metastasis, and 3 cases of distant lymph node metastasis. For the cause of under-staging, there were four cases of patient factor, 19 cases of interpretation factor, and 9 cases of CT factor. In three cases, the cause of under-staging could not be identified. Conclusion: CT interpretation factor was the most frequent cause of under-staging in the preoperative diagnosis with gastric cancer patients. Therefore, more cautious CT interpretation is necessary to avoid unnecessary laparotomies in gastric cancer patients.

• Journal of the Korea Computer Graphics Society
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• v.17 no.1
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• pp.9-16
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• 2011

In this paper, we describe the development of a system for generating a 3-dimensional human face and predicting it's appearance as it ages over subsequent years using 3D scanned facial data and photo images. It is composed of 3-dimensional texture mapping functions, a facial definition parameter input tool, and 3-dimensional facial prediction algorithms. With the texture mapping functions, we can generate a new model of a given face at a specified age using a scanned facial model and photo images. The texture mapping is done using three photo images - a front and two side images of a face. The facial definition parameter input tool is a user interface necessary for texture mapping and used for matching facial feature points between photo images and a 3D scanned facial model in order to obtain material values in high resolution. We have calculated material values for future facial models and predicted future facial models in high resolution with a statistical analysis using 100 scanned facial models.

• Clinical and Experimental Pediatrics
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• v.45 no.12
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• pp.1540-1545
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• 2002

Purpose : Vesicoureteral reflux(VUR) is defined as a retrograde flow of urine from the bladder into the upper urinary tract. It has been shown to predispose patients to hypertension, renal scarring, and end-stage renal failure if not recognized and treated. The observation that VUR occurs in siblings of children with reflux at a significantly higher rate than the general pediatric population has been recognized for many years and VUR was detected in 26% to 51% of siblings of patients with VUR. The purpose of this study is to determine the incidence of VUR in asymptomatic siblings of children with VUR and to see if this form of screening would be practical. Methods : We retrospectively reviewed the records of 28 patients with VUR and their siblings. The total number of asymptomatic siblings investigating VUR were 28 persons. All patients and siblings were evaluated for VUR by a voiding cystourethrography and all patients and siblings with VUR were performed $^{99m}Tc$ 2,3-dimercaptosuccinic acid renal scan. Results : A total of 28 patients(14 boys, 14 girls) with VUR were studied; the mean patient age was 2.7 years(range 1 month to 8.4 years). The total number of asymptomatic siblings investigating VUR were 28 persons(17 boys, 11 girls) and the mean age was 3.3 years(range 2 months to 7.4 years). Renal scar was detected in 20 of 28(71.4%) patients with VUR. VUR was noted in three of 28(10.7%) siblings and renal scar was detected in one of three siblings with VUR. Conclusion : In this study, the predictive value of a positive family history alone in identifying VUR was 10.7%. This incidence suggests more investigation of asymptomatic siblings and continued study of this group of patients at risk is needed for clarifying the family screening of patients with VUR.

• Journal of the Korean Society of Radiology
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• v.15 no.5
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• pp.637-642
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• 2021

Kidney stones are largely classified into kidney stones, ureter stones, and urolithiasis depending on the location of their occurrence. Therefore, in this study, from January 2019 to June 2021, kidney stones found in 112 patients with flank pain or who visited for abdominal ultrasonography at a general hospital located in Daegu were diagnosed with urolithiasis. We wanted to investigate the effect on twinkling artifacts. As a result of the study, the incidence of twinkling artifacts due to kidney stones was relatively high in the longitudinal scan among the scan methods. As the number of kidney stones increased, the incidence of twinkling artifacts increased by 1.296 times (p<0.05). As the kidney stone size increased, the incidence of twinkling artifacts increased by 0.086-fold (p<0.05). It was found that the number and size of kidney stones are factors affecting twinkling artifacts. Since the effect of kidney stones on twinkling artifacts is related to the number and size of kidney stones, continuous attention should be paid to helping the detection of kidney stones by using variables affecting twinkling artifacts.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.1
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• pp.81-90
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• 2004

The state assignment for a finite state machine greatly affects the delay, area, power dissipation, and testabilities of the sequential circuits. In order to improve the testabilities and power consumption, a new state assignment technique . based on m-block partition is introduced in this paper. By the m-block partition algorithm, the dependencies among groups of state variables are minimized and switching activity is further reduced by assigning the codes of the states in the same group considering the state transition probability among the states. In the sequel the length and number of feedback cycles are reduced with minimal switching activity on state variables. It is inherently contradictory problem to optimize the testability and power consumption simultaneously, however our new state assignment technique is able to achieve high fault coverage with less number of scan nfp flops by reducing the number of feedback cycles while the power consumption is kept low upon the low switching activities among state variables. Experiment shows drastic improvement in testabilities and power dissipation for benchmark circuits.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.8
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• pp.1277-1286
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• 2001

Aluminum 5052/Aramid Fiber Reinforced Plastic(Al5052/AFRP) laminates are applied to the fuselage-wing intersection. The Al5052/AFRP laminates suffer from the cyclic bending moment of variable amplitude during the service. Therefore, the influence of cyclic bending moment on the delamination and the fatigue crack propagation behavior in Al5052/AFRP laminate was investigated in this study. Al5052/AFRP laminate composite consists of three thin sheets of Al5052 and two layers of unidirectional aramid fibers. The cyclic bending moment fatigue tests were performed with five different levels of bending moment. The shape and size of the delamination zone formed along the fatigue crack between Al5052 sheet and aramid fiber-adhesive layer were measured by an ultrasonic C-scan. The relationships between da/dN and ΔK, between the cyclic bending moment and the delamination zone size, and between the fiber bridging mechanism and the delamination zone were studied. Fiber failures were not observed in the delamination zone in this study. It represents that the fiber bridging modification factor should turn out to increase and that the fatigue crack growth rate should decrease. The shape of delamination zone turns out to be semi-elliptic with the contour decreased non-linearly toward the crack tip.

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.3
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• pp.261-268
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• 2001

An investigation on nondestructive evaluation of thermal stress-nduced damage in the composite laminates (3mm in thickness and $[+45_6/-45_6]_s$ lay-up angles) has been performed using the thermo-acoustic emission technique. Reduction of thermo-AE events due to repetitive thermal load cycles showed a Kaiser effect. An analysis of the thermo-AE behavior determined the stress free temperature of composite laminates. Fiber fracture and matrix cracks were observed using the optical microscopy, scanning electron microscopy and ultrasonic C-sean. Short-Time Fourier Transform of thermo-AE signals offered the time-frequency characteristics which might classily the thermo-AE as three different types to estimate the damage processes of the composites.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.4
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• pp.45-52
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• 2000

We present a novel method for simple and efficient analysis of the rectangular MQW waveguide. Preferentially two-dimensional structure is transformed into one-dimensional structure by using the effective index method. Then, the characteristic matrix of the resultant planar MQW waveguide is analyzed by scanning angle method. The effective index, modal intensity, and optical confinement factor of rectangular MQW waveguide can be effectively obtained by this method. Our simulation results show excellent agreement with the accurate solutions based on the finite element method. We also introduce the approximation methods for the analysis of rectangular MQW waveguide and investigate their validity. By using perturbation approach, modal power loss of guided wave in rectangular MQW waveguide is newly investigated and compared with the conventional method using the approximation of planar MQW waveguide.