• 제목/요약/키워드: scan pattern

검색결과 395건 처리시간 0.033초

Sclerosing Meningioma : Radiological and Clinical Characteristics of 21 Cases

  • Kang, Ho;Kim, Jin Wook;Se, Young-Bem;Dho, Yun-Sik;Choi, Seung Hong;Park, Sung-Hye
    • Journal of Korean Neurosurgical Society
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    • 제59권6호
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    • pp.584-589
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    • 2016
  • Objective : A rare subtype of meningioma, sclerosing meningioma is not included in the current World Health Organization classification of meningiomas and is classified into the category of other morphological variation subtypes. Sclerosing meningioma is often misdiagnosed to other non-benign meningioma or malignant neoplasm, so it is important to diagnose sclerosing type correctly. We analyzed the radiological and clinical characteristics of a series of sclerosing meningiomas. Methods : Twenty-one patients who underwent surgery in one institute with a histopathologically proven sclerosing meningioma were included from 2006 to 2014. Eighteen tumors were diagnosed as a pure sclerosing-type meningioma, and 3 as mixed type. Magnetic resonance image was taken for all patients including contrast enhancement image. Computed tomography (CT) scan was taken for 16 patients. One neuroradiologist and 1 neurosurgeon reviewed all images retrospectively. Results : In the all 16 patients with preoperative CT images, higher attenuation was observed in the meningioma than in the brain parenchyma, and calcification was observed in 11 (69%). In 15 of the 21 patients (71%), a distinctive very low signal intensity appeared as a dark color in T2-weighted images. Nine of these 15 tumors (60%) exhibited heterogeneous enhancement, and 6 (40%) exhibited homogeneous enhancement that was unlike the homogeneous enhancing pattern shown by conventional meningiomas. Ten patients had a clear tumor margin without peritumoral edema. Conclusion : Although these peculiar radiological characteristics are not unique to sclerosing meningioma, we believe that they are distinctive features that may be helpful for distinguishing sclerosing meningioma from other subtypes.

A Comparative Study of Methods of Measurement of Peripheral Pulse Waveform

  • Kang, Hee-Jung;Lee, Yong-Heum;Kim, Kyung-Chul;Han, Chang-Ho
    • 대한한의학회지
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    • 제30권3호
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    • pp.98-105
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    • 2009
  • Objective: Increased aortic and carotid arterial augmentation index (AI) is associated with the risk of cardiovascular disease. The most widely used approach for determining central arterial AI is by calculating the aortic pressure waveform from radial arterial waveforms using a transfer function. But how the change of waveform by applied pressure and the pattern of the change rely on subject's characteristics has not been recognized. In this study, we use a new method for measuring radial waveform and observe the change of waveform and the deviation of radial AI in the same position by applied pressure. Method: Forty-six non-patient volunteers (31 men and 15 women, age range 21-58 years) were enrolled for this study. Informed consent in a form approved by the institutional review board was obtained in all subjects. Blood pressure was measured on the left upper arm using an oscillometric method, radial pressure waves were recorded with the use of an improved automated tonometry device. DMP-3000(DAEYOMEDI Co., Ltd. Ansan, Korea) has robotics mechanism to scan and trace automatically. For each subject, we performed the procedure 5 times for each applied pressure level. We could thus obtain 5 different radial pulse waveforms for the same person's same position at different applied pressures. All these processes were repeated twice for test reproducibility. Result: Aortic AI, peripheral AI and radial AI were higher in women than in men (P<0.01), radial AI strongly correlated with aortic AI, and radial AI was consistently approximately 39% higher than aortic AI. Relationship between representative radial AI of DMP-3000 and peripheral AI of SphygmoCor had strongly correlation. And there were three patterns in change of pulse waveform. Conclusion: In this study, it is revealed the new device was sufficient to measure how radial AI and radial waveform from the same person at the same time change under applied pressure and it had inverse-proportion to applied pressure.

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NAND 플래시 메모리 기반 파일 시스템을 위한 빠른 마운트 및 안정성 기법 (A Fast Mount and Stability Scheme for a NAND Flash Memory-based File System)

  • 박상오;김성조
    • 한국정보과학회논문지:시스템및이론
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    • 제34권12호
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    • pp.683-695
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    • 2007
  • 기존 NAND 플래시 메모리 기반 파일 시스템은 NAND 플래시 메모리 특성의 하나인 마모도로 인하여 삭제 횟수를 고려해야 하므로 특정 영역을 지속적으로 필요로 하는 정보는 파일 시스템에 저장될 수 없다. 이로 인하여 대부분의 NAND 플래시 메모리 파일 시스템은 마운트될 때 플래시 메모리 전체를 스캔하여 파일 시스템 구조를 파악한다. 따라서 마운트 시간은 NAND 플래시 메모리 크기에 따라 선형적으로 증가할 뿐만 아니라 NAND 플래시 메모리의 사용 형태에 따라 매우 달라 질 수 있다. 또한, NAND 플래시 메모리를 저장 장치로 많이 사용하는 모바일 기기는 특성상 안정적인 전원 공급을 보장받지 못하기 때문에 NAND 플래시 메모리 파일 시스템의 안정성 확보를 위한 대책이 요구 된다. 본 논문에서는 NAND 플래시 메모리 전용 파일 시스템의 마운트 시간을 향상시키고, 예기치 않은 정전과 같은 상황이 발생하여도 파일 시스템이 오동작하지 않고, 일관성 있게 복구가 가능하도록 설계하고 구현하였다. 구현된 파일 시스템은 기존의 NAND 플래시 메모리 기반 파일 시스템인 JFFS2에 비해 최대 19배, YAFFS와는 2배 정도 향상된 마운트 성능을 보였으며, 안정성 측면에서도 좋은 안정성을 가진 JFFS2와 같은 성능을 보였다.

골다공증성 척추 압박골절 환자의 경피적 척추성형술에서 Polymethylmethacrylate의 경막 외 유출 (Epidural Leakage of Polymethylmethacrylate Following Percutaneous Vertebroplasty in the Patients with Osteoporotic Vertebral Compression Fractures)

  • 오윤규;류경식;박춘근;강준기
    • Journal of Korean Neurosurgical Society
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    • 제30권3호
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    • pp.319-324
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    • 2001
  • Objectives : The percutaneous vertebroplasty provides a good result in the treatment of osteoporotic vertebral compression fractures. But, the epidural leakage of polymethylmetacrylate(PMMA) after vertebroplasty may decrease the therapeutic effects because of the compression of thecal sac and/or nerve roots. The authors carried out a prospective study to evaluate the causative factors of epidural leakage of PMMA and to assess the influence on the outcome. Methods : This study involved 347 vertebral levels of compression fractures in 159 patients. Among these, the epidural leakages were identified in 92 vertebral levels(26.5%) in 64 patients(40.3%) on post-operative CT scan. Results : The incidence of epidural leakage of PMMA was significantly higher in the level above T7(p=0.001). The large amount of the injected PMMA and the use of an injector also increased the incidence(p=0.03 and p=0.045, respectively). The position of the needle tip in the vertebral body and the pattern of venous drainage did not influence. The immediate post-operative visual analogue scale(VAS) scores and facial scales(FS) were higher in the patients with epidural leakage(p=0.009). But there were no significant differences between the two groups after three months of operation(p=0.541). Conclusions : The incidence of epidural leakage of PMMA after percutaneous vertebroplasty appears to have relationship with the amount of PMMA and the levels injected. The epidural leakage of PMMA reduced the immediate therapeutic effects of vertebroplasty, but did not influence the late outcome. However, the epidural leakage should be avoided because of its potential neurological complications.

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MRI 검사 시 코일내 최적의 신호강도를 유지할 수 있는 거리의 기준 분석 (Analysis of Distances for MRI Scan to Maintain Pptimal Signal Intensity in a Surface Coil)

  • 손순룡
    • 한국콘텐츠학회논문지
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    • 제18권10호
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    • pp.158-164
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    • 2018
  • 본 연구는 다양한 원인에 의해 코일 중심에 목적 부위를 위치시킬 수 없을 경우 통계적으로 코일 중심과 신호강도가 동일한 기준 거리를 제시하여 최적의 신호강도를 유지할 수 있는 방안을 마련하고자 하였다. 연구방법은 원통형 fluid 팬텀을 코일 중심에서 상 하 방향으로 1 cm 씩 이동시켜 가면서 10 cm 까지 영상을 획득한 후, 신호강도를 측정하여 비교 평가하였다. 연구결과, T1 강조영상은 코일 중심에서 상방향 4 cm와 하방향 1 cm, T2 강조영상은 상방향 5 cm와 하방향 3 cm 이내일 경우 기준인 코일 중심의 신호강도와 유의한 차이가 없음을 알 수 있었다. 결론적으로 본 연구에서 제시한 기준 거리 이내로 영상화하려는 목적 부위를 위치시킨다면 최적의 신호강도를 유지할 수 있으리라 판단된다.

저에너지 집속이온빔리소그라피(FIBL)에 의한 미세패턴 형성 (Micropatterning by Low-Energy Focused ton Beam Lithography(FIBL))

  • 이현용;김민수;정홍배
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1995년도 추계학술대회 논문집
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    • pp.224-227
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    • 1995
  • The micro-patterning by a Bow energy FIB whish has been conventionally utilized far mask-repairing was investigated. Amorphous Se$\_$75/Gee$\_$25/ resist irradiated by 9[keV]-defocused Ga$\^$+/ ion beam(∼10$\^$15/[ions/$\textrm{cm}^2$]) resulted in increasing the optical absorption, which was also observed also in the film exposed by an optical dose of 4.5${\times}$10$\^$20/[photons/$\textrm{cm}^2$]. The ∼0.3[eV] edge shift for ion-irradiated film was about twice to that obtained for photo-exposed. These large shift could be estimated as due to an increase in disorder from the decrease in the sloop of the Urbach tail. For Ga$\^$+/ FIB irradiation with a relatively low energy, 30[keV] and above the amount of dose of 1.4${\times}$10$\^$16/[ions/$\textrm{cm}^2$], the irradiated region in a-Se$\_$75/Ge$\_$25/ resist was perfectly etched in acid solution for 10[sec], which is relatively a short development time. A contrast was about 2.5. In spite of the relatively low incident energy,∼0.225[$\mu\textrm{m}$] pattern was clearly obtained by the irradiation of a dose 6.5${\times}$10$\^$16/[ions/$\textrm{cm}^2$] and a scan diameter 0.2[$\mu\textrm{m}$], from which excellent results were expected fur incident energies above 50[keV] which was conventionally used in FIBL.

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Normal Human Pleural Surface Area Calculated by Computed Tomography Image Data

  • Kim, Doo-Sang;Roh, Hyung-Woon
    • International Journal of Vascular Biomedical Engineering
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    • 제4권1호
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    • pp.27-30
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    • 2006
  • Background; Pleural micro-metastasis of lung cancer is detected by touch print cytology or pleural lavage cytology, but its prognostic impact has not elucidated yet. We hypothesize that recurrence may depend on the amount of tumor cells disseminated in pleural cavity, if the invasiveness of all cancer is the same. To predict the amount of tumor cells disseminated in pleural cavity, we need pleural surface area, distributed pattern of cells and concentration of cells per unit area. Human pleural surface area has not reported yet. In this report, we calculate the normal human pleural surface area using CT image data processing. Methods; Twenty persons were checked CT scan, and we obtained the data from each image. In order to calculate the pleural surface, the outline of lung was firstly extruded from CT image data using home-made Digitizer program. And the distance between CT images was calculated from the extruded outline. Finally a normal human pleural surface was calculated from function between the distance of consecutive CT images and the calculated length. Results; Their mean age is $65{\pm}12$ years old (range $26{\sim}77$), body weight is $62{\pm}9\;kg\;(48{\sim}80)$, and height is $167{\pm}6\;cm\;(156{\sim}176)$. The number of images used is $36{\pm}7\;(24{\sim}51)$. Pleural surface area is $211,888{\pm}35,756\;mm^2\;(143,880{\sim}279,576)$. Right-side pleural surface area is $107,932\;mm^2$ and Lt is $103,955\;mm^2$. Costal, mediastinal and diaphragmatic surfaces of right-side pleura are $77,483\;mm^2,\;39,057\;mm^2,\;and\;8,608\;mm^2$ respectively, and left-side are $72,497\;mm^2,\;35,578\;mm^2,\;and\;4,120\;mm^2$ respectively. Conclusion; Normal human pleural surface area is calculated using CT image data at first and the result is about $0.212\;m^2$.

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A Comparative Study on Virtual Try-on Systems using Body Measurement Input

  • Lim, Ho-Sun;Istook, Cynthia
    • The International Journal of Costume Culture
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    • 제13권2호
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    • pp.118-129
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    • 2010
  • Digital technology introduced into the clothing and fashion industry is evolving to digital virtual fashions and consumer-centered mass-customized production systems. Today the application of such 3D virtual try-on systems is being expanded gradually in the clothing industry. This study purposed to make virtual avatars and virtual garments using OptiTex and V-stitcher virtual software and compared the appearance of the virtual garments put on the virtual avatars. For this, we created virtual avatars and virtual garments using body measurements obtained from jive subjects of top jive body shapes, respectively, using $[TC]^2$ body scanner. According to the results of comparing the outcomes of the two different virtual software systems, virtual avatar II of V-Stitcher tended to have a more round and lifted hip and the waist line at a higher position. In addition, the body curves and shapes of a virtual avatar affect the appearance of virtual garments. This study applied the same body measurements to virtual avatars and the same pattern to virtual garments, but when different kinds of virtual software were used, the virtual avatars and virtual garments showed different appearance and fit. This result may mean that when customers buy apparel products using different kinds of virtual try-on systems, their evaluation of appearance can vary depending on the virtual try-on system. Therefore, research needs to be made actively for the development and use of linkage programs that can reflect actual body measurements between virtual software systems and 3D body scanning systems.

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Three-dimensional finite element analysis of the stress distribution and displacement in different fixation methods of bilateral sagittal split ramus osteotomy

  • Yun, Kyoung In;Cho, Young-Gyu;Lee, Jong-Min;Park, Yoon-Hee;Park, Myung-Kyun;Park, Je Uk
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제38권5호
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    • pp.271-275
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    • 2012
  • Objectives: This study evaluated a range of fixation methods to determine which is best for the postoperative stabilization of a mandibular osteotomy using three-dimensional finite element analysis of the stress distribution on the plate, screw and surrounding bone and displacement of the lower incisors. Materials and Methods: The model was generated using the synthetic skull scan data, and the surface model was changed to a solid model using software. Bilateral sagittal split ramus osteotomy was performed using the program, and 8 different types of fixation methods were evaluated. A vertical load of 10 N was applied to the occlusal surface of the first molar. Results: In the case of bicortical screws, von-Mises stress on the screws and screw hole and deflection of the lower central incisor were minimal in type 2 (inverted L pattern with 3 bicortical repositioning screws). In the case of plates, von-Mises stress was minimal in type 8 (fixation 5 mm above the inferior border of the mandible with 1 metal plate and 4 monocortical screws), and deflection of the lower central incisor was minimal in types 6 (fixation 5 mm below the superior border of the mandible with 1 metal plate and 4 monocortical screws) and 7 (fixation 12 mm below the superior border of the mandible with 1 metal plate and 4 monocortical screws). Conclusion: Types 2 and 6 fixation methods provide better stability than the others.

갑상선 기능 저하증에 의한 수면 무호흡 증후군 1예 (A Case of Sleep Apnea Syndrome due to Primary Hypothyroidism)

  • 위성헌;김상우;최영미;이숙영;문화식;송정섭
    • Tuberculosis and Respiratory Diseases
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    • 제42권2호
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    • pp.238-243
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    • 1995
  • 갑상선 기능저하증은 수면 무호흡 증후군의 한 원인이 될 수 있다. 수면 무호흡 증후군 환자에서 병력과 이학적 검사상 갑상선 기능저하의 가능성에 대한 충분한 평가가 필요하며 갑상선 기능저하증 환자에서도 수면 무호흡 증후군의 증상 및 가능성에 대한 고려가 필요하다. 저자들은 갑상성 기능저하증이 동반된 수면 무호흡 증후군 1예를 경험하였기에 문헌 고찰과 함께 보고하는 바이다.

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