• Title/Summary/Keyword: Flow Reconstruction

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Motor Imagery based Brain-Computer Interface for Cerebellar Ataxia (소뇌 운동실조 이상 환자를 위한 운동상상 기반의 뇌-컴퓨터 인터페이스)

  • Choi, Young-Seok;Shin, Hyun-Chool;Ying, Sarah H.;Newman, Geoffrey I.;Thakor, Nitish
    • Journal of the Korean Institute of Intelligent Systems
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    • v.24 no.6
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    • pp.609-614
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    • 2014
  • Cerebellar ataxia is a steadily progressive neurodegenerative disease associated with loss of motor control, leaving patients unable to walk, talk, or perform activities of daily living. Direct motor instruction in cerebella ataxia patients has limited effectiveness, presumably because an inappropriate closed-loop cerebellar response to the inevitable observed error confounds motor learning mechanisms. Recent studies have validated the age-old technique of employing motor imagery training (mental rehearsal of a movement) to boost motor performance in athletes, much as a champion downhill skier visualizes the course prior to embarking on a run. Could the use of EEG based BCI provide advanced biofeedback to improve motor imagery and provide a "backdoor" to improving motor performance in ataxia patients? In order to determine the feasibility of using EEG-based BCI control in this population, we compare the ability to modulate mu-band power (8-12 Hz) by performing a cued motor imagery task in an ataxia patient and healthy control.

Methods for improving efficiency in Apartment Maintenance Management using on Analytic Hierarchy Process (AHP 기법을 이용한 공동주택 유지관리 효율성 제고 방안)

  • Lee, Jeong-Bok
    • Korean Journal of Construction Engineering and Management
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    • v.7 no.4 s.32
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    • pp.69-77
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    • 2006
  • In recent years, there has been more reconstruction and redevelopment of apartments rather than efforts to consider alternative to extend the life time of the apartments. It is essential to try to develop ways to adequately maintain and to use the apartment facilities efficiently in order to preserve earth environment and the limited resource. However, tacking research on the effects obtained through remodelling and maintenance have interfered with the vitalizing of the market. The objective of this study is to propose criterions and methods with which to evaluate adequacy of maintenance management. A survey was performed to investigate important maintenance methods in order to obtain advices that can smoothly progress improve apartment maintenance management. This study applied AHP(Analytical Hierarchy Process) methods for reasonable maintenance in apartment. Through this study, the flow of apartment maintenance market is elevated to reaching the level in advanced nation.

Effect of the Number of Detectors on Performance of Industrial SPECT (산업용 SPECT의 검출기 개수가 영상 해상도에 미치는 영향 평가)

  • Park, Jang Guen;Kim, Chan Hyeong;Kim, Jong Bum;Moon, Jinho;Jung, Sung-Hee
    • Journal of Radiation Industry
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    • v.5 no.4
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    • pp.325-330
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    • 2011
  • To predict the details of flow in industrial process unit, single photon emission computed tomography (SPECT) is a promising technique. Recently, industrial SPECT based on medical system has developed by researchers of the Korea Atomic Energy Research Institute (KAERI) and Hanyang University. In the present study, to confirm the effect of the number of detectors on image quality, and determine the optimal number of detectors in industrial SPECT, industrial SPECT system with various geometries were evaluated by the Monte Carlo simulation. CsI(Tl) detectors ($12mm{\times}12mm{\times}20mm$) with collimators (the geometric resolution of collimator $R_g$ was 4 cm at the center of the 30 cm diameter cylindrical vessel object) were modeled in a hexagonal array, and the point sources of $^{99m}Tc$, $^{68}Ga$, and $^{137}Cs$ were simulated at the center of the cylindrical vessel object using the MCNPX code. Then, the reconstruction images of each geometry were reconstructed using the expectation maximization (EM) algorithm. In this study, the reciprocity theorem was used to improve computation time required for system matrix of the EM algorithm. The result shows that the resolution of the reconstructed image was significantly improved by increasing the number of detectors in industrial SPECT system and more than 60 detectors will be required for the resolution of the reconstructed image.

A Study on the Holocene Environments of the Jemin Plain in Gongju, Chungnam Province (충남 공주 제민평야의 홀로세 환경연구)

  • PARK, Ji Hoon;LEE, Ae-Jin
    • Journal of The Geomorphological Association of Korea
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    • v.24 no.2
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    • pp.65-78
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    • 2017
  • In this study, stable carbon isotopic analysis (22 specimens) and magnetic susceptibility analysis (23 specimens) were conducted out on the specimens collected from two points (trench DT1, DT2) in the floodplain of Jemincheon(hereinafter the Jemin plain) to reconstruct the Holocene Environments (Period I, Period II, Period III) of the Jemin plain in Gongju, Chungnam. The results were as follows: In Period I (approximately 7,480~4,940 yrs B.P.) and especially around 7,480~7,320 yrs B.P., it was cool-dry and there were two minor climate fluctuations. This period received a continuous flow of sediments, rather than massive amounts of sediments due to abrupt flooding, and therefore, there was almost no soilization process. Period II(approximately 4,940~2,600 yrs B.P.) was also relatively cool-dry. However, in Period II b, unlike I, the minor climate fluctuations were less pronounced. In this period, flooding and desiccation repeated, inducing soilization processes especially around 3,160 yrs B.P. In Stage III (~360 yrs B.P.), it was warm and humid compared to II b. However, in III a, there was no inflow of sediments due to irregular flooding, and in fact, soilization process was more manifested than during II b due to the impact of the desiccation environment. However, there were some mass movements from Bonghwang Mt. (a.s.l. 147m) caused by heavy rains and typhoon during III b (approximately 360 yrs B.P.), thus moving a large amount of debris (i.e. gravel), which resulted in sedimentation.

Patient-specific surgical options for breast cancer-related lymphedema: technical tips

  • Kwon, Jin Geun;Hong, Dae Won;Suh, Hyunsuk Peter;Pak, Changsik John;Hong, Joon Pio
    • Archives of Plastic Surgery
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    • v.48 no.3
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    • pp.246-253
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    • 2021
  • In order to provide a physiological solution for patients with breast cancer-related lymphedema (BCRL), the surgeon must understand where and how the pathology of lymphedema occurred. Based on each patient's pathology, the treatment plan should be carefully decided and individualized. At the authors' institution, the treatment plan is made individually based on each patient's symptoms and relative factors. Most early-stage patients first undergo decongestive therapy and then, depending on the efficacy of the treatment, a surgical approach is suggested. If the patient is indicated for surgery, all the points of lymphatic flow obstruction are carefully examined. Thus a BCRL patient can be considered for lymphaticovenous anastomosis (LVA), a lymph node flap, scar resection, or a combination thereof. LVA targets ectatic superficial collecting lymphatics, which are located within the deep fat layer, and preoperative mapping using ultrasonography is critical. If there is contracture on the axilla, axillary scar removal is indicated to relieve the vein pressure and allow better drainage. Furthermore, removing the scars and reconstructing the fat layer will allow a better chance for the lymphatics to regenerate. After complete removal of scar tissue, a regional fat flap or a superficial circumflex iliac artery perforator flap with lymph node transfer is performed. By deciding the surgical planning for BCRL based on each patient's pathophysiology, optimal outcomes can be achieved. Depending on each patient's pathophysiology, LVA, scar removal, vascularized lymph node transfer with a sufficient adipocutaneous flap, and simultaneous breast reconstruction should be planned.

Satirical expression in Thom Browne's fashion design (톰 브라운 패션디자인에 나타난 풍자적 표현)

  • Kim, Yeonjoo;Lee, Younhee
    • The Research Journal of the Costume Culture
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    • v.29 no.2
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    • pp.252-271
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    • 2021
  • The purpose of this study is to expand satirical expressions that appear in a wide range of arts into fashion and to analyse and present satirical expressions that appear in contemporary fashion through the collections of Thom Browne. Theoretical examination of satirical concepts were made of domestic and foreign academic theses, dissertations, precious studies, and publications related to satire. Analysis was conducted on cases in which satirical expressions were applied in literature, painting, sculpture, and fashion. Based on these studies, analysis was conducted on satirical expressions appearing in Thom Browne's work. Material was gathered from collection reviews, interview articles, professional books, and internet photo material from professional fashion magazines encompassing 16 years of Thom Browne's collections officially recorded in the international fashion magazine 'Vogue', ranging from the 2006 S/S collection to the 2021 S/S collection. From this, a total of 1,753 photos were collected as data. Characteristics of satirical expression were analyzed and the results were as follows. A fluid reconstruction of 'gender fluid', dual meanings of metaphorical allegories, playful expressions of visual wit, constructions made of overlapped disassembled material, and borrowing of morphological distortion were all identified. Accordingly, satirical approaches as social aspects and objects in the flow of modern thought appear as positive forms based in humor that hope to be improved. This study anticipate the concept of satire will expand into a positive form as a new direction of fashion.

3D Ultrasound Panoramic Image Reconstruction using Deep Learning (딥러닝을 활용한 3차원 초음파 파노라마 영상 복원)

  • SiYeoul Lee;Seonho Kim;Dongeon Lee;ChunSu Park;MinWoo Kim
    • Journal of Biomedical Engineering Research
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    • v.44 no.4
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    • pp.255-263
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    • 2023
  • Clinical ultrasound (US) is a widely used imaging modality with various clinical applications. However, capturing a large field of view often requires specialized transducers which have limitations for specific clinical scenarios. Panoramic imaging offers an alternative approach by sequentially aligning image sections acquired from freehand sweeps using a standard transducer. To reconstruct a 3D volume from these 2D sections, an external device can be employed to track the transducer's motion accurately. However, the presence of optical or electrical interferences in a clinical setting often leads to incorrect measurements from such sensors. In this paper, we propose a deep learning (DL) framework that enables the prediction of scan trajectories using only US data, eliminating the need for an external tracking device. Our approach incorporates diverse data types, including correlation volume, optical flow, B-mode images, and rawer data (IQ data). We develop a DL network capable of effectively handling these data types and introduce an attention technique to emphasize crucial local areas for precise trajectory prediction. Through extensive experimentation, we demonstrate the superiority of our proposed method over other DL-based approaches in terms of long trajectory prediction performance. Our findings highlight the potential of employing DL techniques for trajectory estimation in clinical ultrasound, offering a promising alternative for panoramic imaging.

Current Strategy in Endovascular Management for Below-the-Knee Arterial Lesions (무릎 밑 동맥의 혈관 내 치료의 최신 지견)

  • Kyosoo Hwang;Sang Woo Park
    • Journal of the Korean Society of Radiology
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    • v.82 no.3
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    • pp.541-550
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    • 2021
  • The below-the-knee arterial tree is the thinnest of all the leg vessels and is an important path for blood flow to the foot. Hence, lesions including stenosis, especially obstruction, may lead to critical limb ischemia which represents the most severe clinical manifestation of peripheral arterial disease. It is characterized by the presence of ischemic rest pain, ischemic lesions, or gangrene attributable to the objectively proven arterial occlusive disease. Typically, the atherosclerotic disease process involving the below-the-knee arterial tree is diffuse in the majority of patients. The cornerstone of therapy is vascular reconstruction and limb salvage. Revascularization should be attempted whenever technically possible, without delay, in patients presenting critical limb ischemia and when the clinical status is not hopelessly non-ambulatory. Therefore, endovascular treatment can become the gold standard for the full range of patients including below-the-knee, limiting the clinical role of the classically trained surgeons.

Clinical Analysis of Palliative Treatments in Occlusive Vascular Disease (폐쇄성 혈관 질환을 가진 환자의 고식적 치료에 관한 임상적 고찰)

  • 김학제;조원민;류세민;황재준;송영상;최영호
    • Journal of Chest Surgery
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    • v.35 no.4
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    • pp.283-289
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    • 2002
  • Backgrouds: It is almost universally accepted that occlusive vascular diseases are best managed by anatomical reconstruction. However, the mortality and the morbidity have limited this operation for patients with high operation risks. In these patients, palliative operations such as extra-anatomic bypass and lumbar sympathectomy, are accepted as useful treatment. Material and Method: A retrospective study was conducted in 38 patients who underwent palliative operations for occlusive vascular disease at Korea University Guro Hospital between 1996 and 2000. Mean age of the patients was 60.37 $\pm$ 17.65 years, and preoperative diagnoses were atherosclerosis in 32 patients, Buerger's disease in 4 patients, Raynaud's syndrome in 1 patient and SVC syndrome in 1 patient. Result: Extra-anatomic bypass(40procedures), lumbar sympathectomy(17), thromboembolectomy(7) and femoral artery graft interposition(1) were performed. Six patients were required reoperation due to graft flow failure or fistula. Three year primary patency rate of entire operations was 78.29 $\pm$ 8.81%, and the correlation between type of operation and patency rate was not statistically significant. Conclusion: Palliative operations for occlusive vascular disease are useful treatment in limited patients with high operation risks or limited life expectancy.

Evaluation of Cardiac Function Analysis System Using Magnetic Resonance Images

  • Tae, Ki-Sik;Suh, Tae-Suk;Choe, Bo-Young;Lee, Hyoung-Koo;Shinn, Kyung-Sub;Jung, Seung-Eun;Lee, Jae-Moon
    • Progress in Medical Physics
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    • v.10 no.3
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    • pp.159-168
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    • 1999
  • Cardiac disease is one of the leading causes of death in Korea. In quantitative analysis of cardiac function and morphological information by three-dimensional reconstruction of magnetic resonance images, left ventricle provides an important role functionally and physiologically. However, existing procedures mostly rely on the extensive human interaction and are seldom evaluated on clinical applications. In this study, we developed a system which could perform automatic extraction of enpicardial and endocardial contour and analysis of cardiac function to evaluate reliability and stability of each system comparing with the result of ARGUS system offered 1.5T Siemens MRI system and manual method performed by clinicians. For various aspects, we investigated reliability of each system by compared with left ventricular contour, end-diastolic volume (EDV), end-systolic volume (ESV), stock volume (SV), ejection fraction (EF), cardiac output (CO) and wall thickness (WT). When comparing with manual method, extracted results of developed process using minimum error threshold (MET) method that automatically extracts contour from cardiac MR images and ARGUS system were demonstrated as successful rate 90% of the contour extraction. When calculating cardiac function parameters using MET and comparing with using correlation coefficients analysis method, the process extracts endocardial and epicardial contour using MET, values from automatic and ARGUS method agreed with manual values within :t 3% average error. It was successfully demonstrated that automatic method using threshold technique could provide high potential for assessing of each parameters with relatively high reliability compared with manual method. In this study, the method developed in this study could reduce processing time compared with ARGUS and manual method due to a simple threshold technique. This method is useful for diagnosis of cardiac disease, simulating physiological function and amount of blood flow of left ventricle. In addition, this method could be valuable in developing automatic systems in order to apply to other deformable image models.

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