• Journal of Chest Surgery
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• v.32 no.5
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• pp.442-447
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• 1999

Introduction: Understanding the normal distribution of the tracheal diameter and crross- sectional area is one of the key elements in the management of various tracheal pathologies or tracheal reconstruction for the patients in growing age. However, data for Korean standard has been lacking. This study was designed to analyze retrospectively the distribution of tracheal diameter and cross-sectional area in young Koreans, which can afford fundamental data for the management of tracheal diseases. Material and Method: Of the patients who underwent computerized tomogram of the chest between May 1996 and August 1998, one hundred six young patients(age range: 0-20 years) were included. Patients with any conditions which might affect the tracheal cross-sectional area or diameter, such as tracheal disease, previous operation, mediastinal tumor, or obstructive lung disease were excluded from the study. Gender distribution was 69 males and 37 females. Tracheal diameters, anterior-posterior and transverse, were measured at the level of the thoracic inlet(level I) and the aortic arch(level II). Types of the trachea were divided into round, oval, or horseshoe shaped on cross-sectional view, and the dimension was calculated by using the equation of A=1/4$\pi$ab(A; area, $\pi$; 3.14, a; anterior-posterior diameter, b; transverse diameter). We analyzed the distribution of the diameter at each level and compared the cross-sectional area with respect to age and gender. A p-value lower than 0.05 wa considered significant. Result: The trachea of patients less than 5 years old were round in shape at both of level I and II, and no differences in cross-sectional area was observed between the levels(p=NS). As the age increased, the trachea become oval in shape at level I while it remained round in shape at level II(p=0.020). The tracheal diameter and cross-sectional area increased as the age increased with a linear correlation(r>0.9). In patients less than 5 years of age, female patients showed larger cross-sectional area than male patients (p=0.020), and it was reversed in patients older than 15 years of age(p=0.002). Conclusion: From the above results, we suggest chest computerized tomogram as a safe and reliable tool in measuring the tracheal diameter and cross-sectional area. We also provide the data as a standard for distribution of the tracheal diameter and cross-sectional area in young Korean population.

• The Journal of the Petrological Society of Korea
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• v.25 no.3
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• pp.169-193
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• 2016

In order to characterize the Neotectonic crustal deformation and current stress field in and around the Korean Peninsula and to interpret their tectonic implications, this paper synthetically analyzes the previous Quaternary fault and focal mechanism solution data and recent geotechnical in-situ stress data and examines the characteristics of crustal deformations and tectonic settings in and around East Asia after the Miocene. Most of the Quaternary fault outcrops in SE Korea occur along major inherited fault zones and show a NS-striking top-to-the-west thrust geometry, indicating that the faults were produced by local reactivation of appropriately oriented preexisting weaknesses under EW-trending pure compressional stress field. The focal mechanism solutions in and around the Korean Peninsula disclose that strike-slip faulting containing some reverse-slip component and reverse-slip faulting are significantly dominant on land and in sea area, respectively. The P-axes are horizontally clustered in ENE-WSW direction, whereas the T-axes are girdle-distributed in NNW direction. The geotechnical in-situ stress data in South Korea also indicate the ENE-trending maximum horizontal stress. The current crustal deformation in the Korean Peninsula is thus characterized by crustal contraction under regional ENE-WSW or E-W compression stress field. Based on the regional stress trajectories in and around East Asia, the current stress regime is interpreted to have resulted from the cooperation of westward shallow subduction of the Pacific Plate and collision of Indian and Eurasian continents, whereas the Philippine Sea plate have not a decisive effect on the stress-regime in the Korean Peninsula due to its high-angle subduction that resulted in dominant crust extension of the back-arc region. It is also interpreted that the Neotectonic crustal deformation and present-day tectonic setting of East Asia commenced with the change of the Pacific Plate motion during 5~3.2 Ma.

• Childhood Kidney Diseases
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• v.5 no.1
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• pp.36-42
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• 2001

Purpose : Vesicoureteral reflux is the most commonly inherited disease detected in children with urinary tract infection. The incidence of vesicoureteral reflux among siblings of children with known vesicoureteral reflux is 8$\%$ to 45$\%$ according to different authors. Family screening of a patient with vesicoureteral reflux is important in order to prevent reflux nephropathy. The purpose of this study is to determine the incidence of vesicoureteral reflux in asymptomatic family of children with vesicoureteral reflux and the factors which influence the family history. Methods : The study group consisted of 27 families of patients with vesicoureteral reflux. The total number in the group were 79 persons. BUN, Cr, urineanalysis, voidingcystourethrography(VCUG) and 99mTc -dimercaptosuccinic acid(DMSA) renal scan were performed oil tile siblings. As for tile parents the same tests were performed except the VCUG. Results : The abnormality was detected in 7 of 27 families(25.9$\%$). Vesicoureteral reflux was detected in 5 of 20 siblings and renal scar ns detected in 3 of 32 parents. In children with vesicoureteral reflux, renal scar was detected in 24 of 32 children. Between the group with the abnormality in its family(Group A) and the group without the abnormality in its family(Group B), There was no difference of creatinine clearance between two groups. More renal scars were detected in group A according to the DMSA(A:100$\%$, B:75$\%$. t-test P<0.05). There was no difference of grade of VCUG between two groups. There was no difference between one site and both sites in two groups. In tile case of tile siblings with vesicoureteral reflux, there was high incidence of renal scar in a patient with vesicoureteral reflux according to the DMSA. Conclusion : It is important to screen vesicoureteral reflux and renal scar in case of urinary tract infection to prevent reflux nephropathy. This study implies that it is necessary to screen the family of a patient with vesicoureteral reflux especially with renal scar. (J, Korean Soc Pediatr Nephrol 5 : 36- 42, 2001)

• The Korean Journal of Nuclear Medicine
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• v.38 no.3
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• pp.259-267
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• 2004

Purpose: NEMA NU2-2001 was proposed as a new standard for performance evaluation of whole body PET scanners. in this study, system performance of Siemens CTI ECAT EXACT 47 PET scanner including spatial resolution, sensitivity, scatter fraction, and count rate performance in 2D and 3D mode was evaluated using this new standard method. Methods: ECAT EXACT 47 is a BGO crystal based PET scanner and covers an axial field of view (FOV) of 16.2 cm. Retractable septa allow 2D and 3D data acquisition. All the PET data were acquired according to the NEMA NU2-2001 protocols (coincidence window: 12 ns, energy window: $250{\sim}650$ keV). For the spatial resolution measurement, F-18 point source was placed at the center of the axial FOV((a) x=0, and y=1, (b)x=0, and y=10, (c)x=70, and y=0cm) and a position one fourth of the axial FOV from the center ((a) x=0, and y=1, (b)x=0, and y=10, (c)x=10, and y=0cm). In this case, x and y are transaxial horizontal and vertical, and z is the scanner's axial direction. Images were reconstructed using FBP with ramp filter without any post processing. To measure the system sensitivity, NEMA sensitivity phantom filled with F-18 solution and surrounded by $1{\sim}5$ aluminum sleeves were scanned at the center of transaxial FOV and 10 cm offset from the center. Attenuation free values of sensitivity wire estimated by extrapolating data to the zero wall thickness. NEMA scatter phantom with length of 70 cm was filled with F-18 or C-11solution (2D: 2,900 MBq, 3D: 407 MBq), and coincidence count rates wire measured for 7 half-lives to obtain noise equivalent count rate (MECR) and scatter fraction. We confirmed that dead time loss of the last flame were below 1%. Scatter fraction was estimated by averaging the true to background (staffer+random) ratios of last 3 frames in which the fractions of random rate art negligibly small. Results: Axial and transverse resolutions at 1cm offset from the center were 0.62 and 0.66 cm (FBP in 2D and 3D), and 0.67 and 0.69 cm (FBP in 2D and 3D). Axial, transverse radial, and transverse tangential resolutions at 10cm offset from the center were 0.72 and 0.68 cm (FBP in 2D and 3D), 0.63 and 0.66 cm (FBP in 2D and 3D), and 0.72 and 0.66 cm (FBP in 2D and 3D). Sensitivity values were 708.6 (2D), 2931.3 (3D) counts/sec/MBq at the center and 728.7 (2D, 3398.2 (3D) counts/sec/MBq at 10 cm offset from the center. Scatter fractions were 0.19 (2D) and 0.49 (3D). Peak true count rate and NECR were 64.0 kcps at 40.1 kBq/mL and 49.6 kcps at 40.1 kBq/mL in 2D and 53.7 kcps at 4.76 kBq/mL and 26.4 kcps at 4.47 kBq/mL in 3D. Conclusion: Information about the performance of CTI ECAT EXACT 47 PET scanner reported in this study will be useful for the quantitative analysis of data and determination of optimal image acquisition protocols using this widely used scanner for clinical and research purposes.

• Economic and Environmental Geology
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• v.28 no.6
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• pp.579-585
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• 1995

The Samkwang mine is Cretaceous gold-silver-bearing deposits located in the western part of the Ogcheon belt The ore deposits have been emplaced within granite gneiss of the Precambrian age. The Au-Ag deposits are hydrothermal-vein type, characterized by arsenic-, gold- and silver-bearing sulphides, in addition to the principal ore-forming sulphides arsenopyrite, galena, sphalerite, chalcopyrite, pyrite and pyrrhotite. Their proven reserves are 355,000 MT, and grades are 8.4 g Au/t and 13.6 g Ag/t. On the basis of their structural characters, the Au-Ag-bearing quartz veins are classified into three types of ore veins; (1) The Main vein shows $N40^{\circ}-80^{\circ}E$ strike and $55^{\circ}-90^{\circ}SE$ dip, (2) the Sangban vein shows E-W strike and $30^{\circ}-40^{\circ}S$ dip, and (3) the Gukseong vein has $N25^{\circ}-40^{\circ}W$strike and $65^{\circ}-80^{\circ}SW$ dip. The emplacements of the ore veins are closely related to the minimum stress axis $({\sigma}_3)$ during the strike-slip movement of the study area. The ore-bearing veins filled with extension fractures during strike-slip movements were sequentially emplaced as follows: I) When ${\sigma}_1$ operates obliquely to NE-series discontinous surface, the Main fault zone $(F_1)$ developes. 2) During the same time, extension fractures ($T_1$ Gukseong veins) take place. 3) When the fault progress continuously, the existing $T_1$, may be high angle and $T_2$ (Daehung vein) developes continuously. 4) When ${\sigma}_1$ changes to sinistral sense, $T_3$ (basic dyke) occurs. 5) When a reverse fault becomes active, the Sangban vein is branched from the Guksabong vein.

• The Korean Journal of Nuclear Medicine
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• v.35 no.4
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• pp.241-250
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• 2001

Purpose: Vasospasm is a complication of aneurysmal subarachnoid hemorrhage (aSAH). We assessed the role of acetazolamide-enhanced brain perfusion SPECT (ACZ-SPECT) with Tc-99m ECD for predicting the prognosis of patients with aSAH. Materials and methods: Two SPECT studios (baseline with 740 MBq and ACZ-SPECT with 1480 MBq) with image subtraction were performed in 21 patients with aSAH. All patients had brain CT and angiogram. Vasoreactivity on ACZ-SPECT, perfusion defect on baseline SPECT, and vasospasm on angiogram were correlated with Hunt-Hess grading, extent of SAH (unilateral or bilateral) on CT, and clinical outcome. Vasoreactivity was considered decreased when cerebral/cerebellar uptake ratio difference from baseline SPECT to ACZ-SPECT was greater than 2SD of normal control values. Results: Decreased vasoreactivity was observed in 38% (8/21), perfusion defect in 81% (17/21), and vasospasm in 38% (8/21). The preserved vasoreactivity group showed better outcome scale (92%, 12/13) and the decreased vasoreactivity group showed poorer outcome scale (62.5%, 5/8) (p=0.014). Extensive SAH was more frequently seen in the decreased vasoreactlvlty group (87.5%, 7/8) than in the preserved vasoreactivity group (30.7%, 4/13)(p=0.017). The perfusion defect and vasospasm did not show good correlation with outcome scale, extent of SAH, and Hunt-Hess grading (p=ns). Vasoreactivity represented the patient's outcome better than the vasospasm in all of the vasoreactivity/vasospasm-mismatched cases (6 cases). Conclusions: Our data show that decreased vasoreactivity on ACZ-SPECT does not always represent vasospastic condition. But patients with decreased vasoreactivity reveal poorer outcome than patients with angiographic vasospasm do. Therefore ACZ-SPECT is a valuable, noninvasive test for predicting the prognosis of patients with aSAH.

• Childhood Kidney Diseases
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• v.3 no.1
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• pp.64-71
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• 1999

Purpose : The protective effects of dietary protein on the progression of renal failure were studied in subtotally nephrectomized rats. Methods : Treatment groups were as follows; 5/6 nephrectomy and a normal protein ($18.5\%$) diet (NP); 5/6 nephrectomy and a low protein ($6\%$) diet (LP): 5/6 nephrectomy, a normal protein diet and converting enzyme inhibitor, enalapril (NPE): 5/6 nephrectomy, a low protein diet and enalapril (LPE). Both diets were isocaloric and had the same phosphorus content. Proteinuria, remnant kidney weight, mesangial matrix expansion score and glomerular volume were assessed at 4, 12 and 16 weeks after renal ablation. Results : LP and NP developed progressive hypertension. Eight weeks after surgery, LPE and NPE controlled hypertension. LP, LPE, and NPE had significantly less proteinuria than NP at 16 weeks (P<0.05). Kidney weight in LP were markedly less enlarged than NP (P<0.05). There was no difference in kidney weight between LPE and NPE. At 12 and 16 weeks the mesangial matrix expansion score was significantly less in LP, LPE, and NPE compared to NP (P<0.05). At 12 and 16 weeks mean glomerular volume was significantly less in LP compared to NP (P<0.05). At 12 and 16 weeks mean glomerular volume in LPE was significantly less compared to NPE. Conclusion : Dietary protein restriction afforded considerable protection from renal injury in the rat remnant kidney model. During the enalapril treatment, there was no additional protective effect of dietary protein restriction against the development of renal lesions.

• Archives of design research
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• no.16
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• pp.41-51
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• 1996

A matter of primary concern about all design is concentrated on how to create more valuable things to allow people to live an affluent life. However, it is very difficult to achieve the goal because every design work is changed in accordance with given situatio ns. In this sense, it is significant to study on biodesign because it can be both a basic principle and a fudamantal index to show the way of new design direction. Accordingly, the main purpose of the thesis is to catch every meaning of bio-design and to close analyze its factors in order to generate more fresh ideas and put them into practice. The thesis is composed of five Chapters: Introduction, Background of bio-design, Principle of bio-design, Practice of bio-design, and Conclusion. In Introduction, the purpose and background of the study are presented. I n Chapter 2, source of design orgin, vernacular design, and design for life are researched. In Chapter 3, organic order. the survial of the fittest, and subjective & objective are considered. In Chapter 4, hi-tech & hi-touch, criteria of problem -solving, and harmony with nature are searched. In Conclusion, some suggestive words on the study are mentioned.

• The Journal of the Acoustical Society of Korea
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• v.26 no.7
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• pp.343-352
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• 2007

The present study aims to investigate the design standard for acoustic criteria of Korean traditional music which could be used for the design of Korean traditional music halls. In order to do this, subjective listening tests were undertaken to musicians using auralized sounds which were convolved with the impulse response of traditional instruments recorded in an anechoic chamber. 94 pairs of sound were made which have different value of acoustic parameters including RT, BR, Brilliance, G, C80, ITDG, IACC. A paired comparison method(PCM) was used to analyze the results from the subjective listening tests. The results show that the preference of acoustic criteria for the Korean traditional music is far different from those of western music. As a result, specific range of acoustic criteria were suggested for the appropriate acoustic conditions of Korean traditional music. Also, a guideline of the acoustic design of halls for performing the Korean traditional music was suggested which could be used as a basic reference in the future works.

• Journal of Chest Surgery
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• v.30 no.3
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• pp.308-314
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• 1997

A retrospective review of the histopathology and clinical information of primary lung cancer was performed to investigate the trends in the histologic type related to sex, age, and smoking history. During January 1988 and July 1995, 541 pateints were diagnosed as primary lung cancer at the Korea Univeristy Anam Hospital. Male (423) to female(118) ratio was 3. 6:1. The most frequent histologic type of lung cancer in male patients was squamous cell carcinoma (223 patients, 52.7%) followed by adenocarcinoma (86, 20.3%) and small cell carcinoma (85, 20.1 %). In female patients, adenocarcinoma (64, 54.2%) wa most common, which was followed by squamous cell carcinoma (22, 18.6%) and small cell carcinoma (22, 18. 6%). The incidence of adenocarnimoma had an increased tendency recently (14.3% in 1988, 33.3% in 1995)(P=0.019). The predominant type in smokers was squamous cell carcinoma; whereas adenocarcinoma was the most frequent type in non-smokers. The proportion of patients aged less than 40 years (younger group) was 4. 0% (n=22). Of them, adenocarcinoma (7) and small cell carcinoma (7) were most common. In patients older than 40 years (older group, n=519), 243 (46.8%) patients had squamous cell carcinoma, and 143 (27.6%) adenocarcinoma. As age increased, the prevalence of squamous cell carcinoma was increased (P=0.0005), adenocarcinoma decreased (P=NS), and small cell carcinoma remained unchanged. We suggest above data as a clinical guidance for management of primary lung cancer.