• Clinical and Experimental Pediatrics
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• v.46 no.6
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• pp.566-571
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• 2003

Purpose : Leukoencephalopathy(LE) is one of the most serious complications in children with hematologic malignancies during the course of treatment. Early recognition is important to reduce the impact and sequelae from LE. We therefore investigated the clinical features of LE following central nervous system(CNS) prophylaxis in children with hematologic malignancies and evaluated the significance of regular check-ups of brain MRI. Methods : We retrospectively reviewed children with hematologic malignancies who had CNS prophylaxis including intrathecal(IT) methotrexate(MTX) and/or cranial irradiation at the Department of Pediatrics, Kyungpook National University Hospital from Oct. 1995 to May 2002. Fifteen cases of acute leukemia and one case of lymphoma who experienced LE following CNS prophylaxis were included in the study. Clinical data were analyzed from the medical records and brain MRIs were reviewed by neuroradiologists. Results : The ages ranged from 1 to 13 years(median age=5.2 years), and the male to female ratio was 3 : 1. The time interval from the beginning of chemotherapy to the time of diagnosis of LE ranged from 2 to 17 months. They all had IT MTX two to 15 times and ten underwent cranial irradiation(1,800 rads). At the time of diagnosis, ten of them had neuropsychiatric symptoms including seizures, personality changes, headache, etc. After the change of treatment modality, four cases showed significant improvement on follow-up MRIs, six cases had no significant changes and two had worsening of LE. Four patients died of infection and bone marrow relapse. Conclusion : CNS prophylaxis with IT therapy and cranial irradiation may cause leukoencephalopathy during the course of treatment. As a result, regular brain MRI check-up is recommended for the early detection and reducing the incidence of LE, along with changes in the treatment modality.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.1
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• pp.1-11
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• 2015

Purpose : Evaluating absorbed dose related to 2D and 3D imaging confirmation devices Materials and Methods : According to the radiographic projection conditions, absorbed doses are measured that 3 glass dosimeters attached to the centers of 0', 90', 180' and 270' in the head, thorax and abdomen each with Rando phantom are used in field size $26.6{\times}20$, $15{\times}15$. In the same way, absorbed doses are measured for width 16cm and 10cm of CBCT each. OBI(version 1.5) system and calibrated glass dosimeters are used for the measurement. Results : AP projection for 2D imaging check, In $0^{\circ}$ degree absorbed doses measured in the head were $1.44{\pm}0.26mGy$ with the field size $26.6{\times}20$, $1.17{\pm}0.02mGy$ with the field size $15{\times}15$. With the same method, absorbed doses in the thorax were $3.08{\pm}0.86mGy$ to $0.57{\pm}0.02mGy$ by reducing field size. In the abdomen, absorbed dose were reduced $8.19{\pm}0.54mGy$ to $4.19{\pm}0.09mGy$. Finally according to the field size, absorbed doses has decreased by average 5~12%. With Lateral projection, absorbed doses showed average 5~8% decrease. CBCT for 3D imaging check, CBDI in the head were $4.39{\pm}0.11mGy$ to $3.99{\pm}0.13mGy$ by reducing the width 16cm to 10cm. In the same way in thorax the absorbed dose were reduced $34.88{\pm}0.93(10.48{\pm}0.09)mGy$ to $31.01{\pm}0.3(9.30{\pm}0.09)mGy$ and $35.99{\pm}1.86mGy$ to $32.27{\pm}1.35mGy$ in the abdomen. With variation of width 16cm and 10cm, they showed 8~11% decrease. Conclusion : By means of reducing 2D field size, absorbed dose were decreased average 5~12% in 3D width size 8~11%. So that it is necessary for radiation therapists to recognize systematical management for absorbed dose for Imaging confirmation. and also for frequent CBCT, it is considered whether or not prescribed dose for RT refer to imaging dose.

• Radiation Oncology Journal
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• v.13 no.4
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• pp.403-409
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• 1995

Purpose : Authors tried to enhance the safety and accuracy of radiosurgery by verifying stereotacitc target point in actual treatment position prior to irradiation. Materials and Methods : Before the actual treatment, several sections of anthropomorphic head phantom were used to create a condition of unknown coordinates of the target point. A film was sandwitched between the phantom sections and punctured by sharp needle tip. The tip of the needle represented the target point. The head phantom was fixed to the stereotactic ring and CT scan was done with CT localizer attached to the ring. After the CT scanning, the stereotactic coordinates of the target point were determined. The head phantom was secured to accelerator's treatment couch and the movement of laser isocenter to the stereotactic coordinates determined by CT scanning was performed using target positioner. Accelerator's anteroposterior and lateral portal films were taken using angiographic localizers. The stereotactic coordinates determined by analysis of portal films were compared with the stereotactic coordinates previously determined by CT scanning. Following the correction of discrepancy the head phantom was irradiated using a stereotactic technique of several arcs. After the irradiation, the film which was sandwitched between the phantom sections was developed and the degree of coincidence between the center of the radiation distribution with the target point represented by the hole in the film was measured. In the treatment of the actual patients, the way of determining the stereotactic coordinates with CT localizers and angiograuhic localizers was the same as the phantom study. After the correction of the discrepancy between two sets of coordinates, we proceeded to the irradiation of the actual patient. Results : In the phantom study, the agreement between the center of the radiation distribution and the localized target point was very good. By measuring optical density profiles of the sandwitched film along axes that intersected the target point, authors could confirm the discrepancy was 0.3 mm. In the treatment of an actual patient, the discrepancy between the stereotactic coordinates with CT localizers and angiographic localizers was 0.6 mm. Conclusion : By verifying stereotactic target point in actual treatment position prior to irradiation, the accuracy and safety of streotactic radiosurgery procedure were established.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.6
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• pp.483-488
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• 2007

The aerodynamic characteristics of FAST(Future Air Speed Transit) combined the body with tandem wing flying over nonplanar ground surface are investigated by using a boundary element method. To validate the present method, results of the present analysis are compared with the experiment and other numerical results. The arrangement of the tandem wing is determined to secure sufficient aero-levitation force and the stability through the analysis of the aerodynamic characteristics of the FAST. The FAST has the maximum lift characteristics when the tandem wing with lower endplate is located at the front side and the rear side of the body. The stability of the FAST can be secured by using the flaperon of the tandem wing.

• Archives of Craniofacial Surgery
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• v.10 no.1
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• pp.37-39
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• 2009

Purpose: Langerhans cell histiocytosis is a heterogenous group of Langerhans cell proliferative disorders and includes eosinophilic granuloma, Letterer-Siwe diseases, and Hand-Schuller Christian disease. We report a case of eosinophilic granuloma on frontal area. Methods: A 17-year-old male presented with swelling and tenderness on Lt. frontal and periorbital area. CT and MRI showed a $33{\times}25mm$ sized mass that involved Lt. frontal calvarium, frontotemporal meninges, and orbital roof. Results: Total excision of the mass and adjacent soft tissue, calvarium, and orbital roof was performed. Orbital roof defect was reconstructed with absorbable plate and calvarial defect was done with outer cortex of temporal bone flap. The histology revealed proliferation of histiocytes and eosinophils. Immunologically, these histiocytic cells expressed S-100 protein and CD1a. The patient is currently taking conservative treatment. Conclusion: The severity of these disease and their prognosis and treatments are various. For unifocal cranial Langerhans cell histiocytosis, complete excision is the treatment of choice. We report this case with review of literature.

• Journal of Yeungnam Medical Science
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• v.16 no.2
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• pp.364-368
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• 1999

A rare case of telangiectatic osteosarcoma of the sphenoid bone was reported. The patient was a 27-year-old male and had suffered from left eye protrusion and diplopia for three months. Radiologically, a lobulated osteolytic lesion was located between sphenoid and left temporal bone. Pathologically, the tumor had multiloculated blood filled cystic vascular spaces and osteoid formation by malignant spindle osteoblast cells. The differential diagnosis of this rare entity from aneurysmal bone cyst was important radiologically and pathologically. This case is the second case of telangiectatic osteosarcoma of the sphenoid bone followed by a case of Whitehead RE and Melhem ER in 1998.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1827-1834
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• 2007

The purpose of research will establish the foundation to enhance the skills of Railway Color Design in the future by accurately analysing the Railway Color characteristics. The emotion and demnds of times influences trend of Railway Color Design, the contents of this research also reflects trend in society and culture. The research contains the history of Railway Design and advance research of Railway Color trend especially influenced by society and culture in the from the 1960's to the year 2005. The study is based on the concept of Railway Color Design. it analyzed the related current of society, culture and Railway Color. Collected Railway Color samples(Railway 46 images) were studied by using visual sensation. The Munsell Color System was used as references. This research analyzed railway introduced as railway models by top 4 nation (United Kingdom, Germany, France, Japan) and Korea in the past years(1960-2005) for their Railway Color Design trend by Munsell Color System. Although the Railway industry has rapidly risen according to life style in society and culture, there has been a lack of organized data for Railway Color Planing. this research on the basis will offer the significant information for Railway Color Design.

• Korean Journal of Ichthyology
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• v.28 no.2
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• pp.121-124
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• 2016

A single specimen of Ariosoma meeki, belonging to the family Congridae, was collected for the first time from Jinhae-gu, Changwon-si, Gyeongsangnam-do, Korea, on June 10, 2015. Ariosoma meeki is characterized by an absence of scales on its whole body, dorsal and anal fin connected to the caudal fin, blackish margins of the dorsal and anal fin, posterior nostrils not covered with a dermal flap, 60 preanal lateral-line pores, 15 pectoral fin rays, no cephalic sensory pore between the interorbital region and dorsal fin origin, and two dark brown dots behind the eyes. We described it as the new Korean record, and proposed the Korean name "nun-te-bung-jang-eo" for this species A. meeki.

• Applied Microscopy
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• v.31 no.2
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• pp.143-156
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• 2001

The aim of this study was to clarify the differentiation of seminiferous epithelial cells and spermiogenesis in the testis of Rana catesbeiana. Spermatogenesis of R. catesbeiana consists of primary spermatogonia, secondary spermatogonia, primary spermatocytes, secondary spermatocytes and spermatids. They were subdivided into eight stages on the basis of the morphological features of the germ cell differentiation. From the spermatocytes except primary spermatogonia to before the spermiation of spermatids were surrounded by spermatocyst. Spermiogenesis of R. catesbeiana can also be divided into three stages on the basis of morphological features of the nucleus and the cytoplasm organelles. Spermatozoon contained a saccular acrosome, a cylindrical and tapered slighty at both ends head, and a tail with only the axoneme.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.351-357
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• 2003

The optimal design for a leading car considering the aerodynamic resistance is required on the high-speed train due to increasing of ratio of drag force with proportion for the square of velocity. The aerodynamic analysis using CFD in the stage of concept design offers more economical analysis method which is used to estimate the influence of flow and pressure around the leading car than the experimental method using the Mock-up. In this study, we want to assist the artistic design with aerodynamics analysis in order to get the optimal design for leading car with the operation speed at 180km/h. The results of aerodynamic analysis for two leading car models which one is expressed with lineal beauty and the other is with curvaceous beauty are compared with each other and they offer the proposal of modification for two models in order to decrease the drag force. The shape of curvaceous model is better for the pressure force but slightly worse for the viscous force than the other. The Fluent software is used for the calculation of flow profile in this study.