• Title/Summary/Keyword: CT complex

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AUTOMATIC ADJUSTMENT OF DISCREPANCIES BETWEEN LIDAR DATA STRIPS - USING THE CONTOUR TREE AND ITERATIVE CLOSEST POINT ALGORITHM

  • Lee, Jae-Bin;Han, Dong-Yeob;Yu, Ki-Yun;Kim, Yong-Il
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.500-503
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    • 2006
  • To adjust the discrepancy between Light Detection and Ranging (LIDAR) strips, previous researches generally have been conducted using conjugate features, which are called feature-based approaches. However, irrespective of the type of features used, the adjustment process relies upon the existence of suitable conjugate features within the overlapping area and the ability of employed methods to detect and extract the features. These limitations make the process complex and sometimes limit the applicability of developed methodologies because of a lack of suitable features in overlapping areas. To address these drawbacks, this paper presents a methodology using area-based algorithms. This approach is based on the scheme that discrepancies make complex the local height variations of LIDAR data whithin overlapping area. This scheme can be helpful to determine an appropriate transformation for adjustment in the way that minimizes the geographical complexity. During the process, the contour tree (CT) was used to represent the geological characteristics of LIDAR points in overlapping area and the Iterative Closest Points (ICP) algorithm was applied to automatically determine parameters of transformation. After transformation, discrepancies were measured again and the results were evaluated statistically. This research provides a robust methodology without restrictions involved in methods that employ conjugate features. Our method also makes the overall adjustment process generally applicable and automated.

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Genetic Algorithm based B-spline Fitting for Contour Extraction from a Sequence of Images (연속 영상에서의 경계추출을 위한 유전자 알고리즘 기반의 B-spline 적합)

  • Heo Hoon;Lee JeongHeon;Chae OkSam
    • Journal of KIISE:Software and Applications
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    • v.32 no.5
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    • pp.357-365
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    • 2005
  • We present a B-spline fitting method based on genetic algorithm for the extraction of object contours from the complex image sequence, where objects with similar shape and intensity are adjacent each other. The proposed algorithm solves common malfitting problem of the existing B-spline fitting methods including snakes. Classical snake algorithms have not been successful in such an image sequence due to the difficulty in initialization and existence of multiple extrema. We propose a B-spline fitting method using a genetic algorithm with a new initial population generation and fitting function, that are designed to take advantage of the contour of the previous slice. The test results show that the proposed method extracts contour of individual object successfully from the complex image sequence. We validate the algorithm by false-positive/negative errors and relative amounts of agreements.

Transient Hypoglossal Nerve Palsy after Open Reduction of Zygomatic Complex Fracture (관골복합골절 수술 후 발생한 일시적 설하신경 마비의 증례보고)

  • Kim, Jee Wook;Kim, Woo Seob;Kwon, Nam Ho;Kim, Han Koo;Bae, Tae Hui
    • Archives of Plastic Surgery
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    • v.36 no.1
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    • pp.80-83
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    • 2009
  • Purpose: Isolated hypoglossal nerve palsy is a rare manifestation of various underlying disease. This article presents a rare complication of general anesthesia associated with an surgical procedure on a case of zygomatic fracture. Methods: An 18-year-old female patient was referred to our department by painful swelling on her left zygomatic area after the traffic accident. Left zygomatic complex fracture was identified on the simple x-ray and facial bone CT scan, and the fracture was treated with open reduction and internal fixation under general anesthesia. On the first postoperative day, she complained of difficulty in swallowing solid food, dysarthria and deviated tongue to her right side. There was no abnormal findings on the neurological examination, brain MRI and routine chemistry. She was diagnosed with transient hypoglossal nerve palsy and dexamethasone with multi-vitamins was administrated intravenously for 5 days. Results: The symptoms were completely resolved by the ninth postoperative day and the patient was discharged without any other complications. Conclusion: The hypoglossal(cranial nerve XII)nerve supplies motor innervation to all of the ipsilateral extrinsic and intrinsic tongue muscles. The hypoglossal nerve damage may caused by the compression between the airway and the hyoid bone during the endotracheal intubation, and direct trauma due to excessive pressure or neck extension. We described a rare case of unintended injury to hypoglossal nerve and care must be taken not to cause the hypoglossal nerve damage especially in facial plastic surgery with excessive neck extension under general anesthesia.

Synthesis and radiolabeling of PEGylated dendrimer-G2-Gemifloxacin with 99mTc to Biodistribution study in rabbit

  • Mohtavinejad, Naser;Dolatshahi, Shaya;Amanlou, Massoud;Ardestani, Mehdi Shafiee;Asadi, Mehdi;Pormohammad, Ali
    • Advances in nano research
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    • v.10 no.5
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    • pp.461-470
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    • 2021
  • Infection is one of the major mortality causes throughout the globe. Nuclear medicine plays an important role in diagnosis of deep infections such as osteomyelitis, arthritis infection, heart valve and heart prosthesis infections. Techniques such as labeled leukocytes are sensitive and selective for tracking the inflammations but they are not suitable for differentiating infection from inflammation. Anionic linear-globular dendrimer-G2 was synthesized then conjugation to gemifloxacin antibiotic. The structures were identified by FT-IR, 1H-NMR, C-NMR, LC-MS and DLS. The toxicity of gemifloxacin and dendrimer-gemifloxacin complex was compared by MTT test. Dendrimer-G2-gemifloxacin was labeled by Technetium-99m and its in-vitro stability and radiochemical purity were investigated. In-vivo biodistribution and SPECT imaging were studied in a rabbit model. Identify and verify the structure of the each object was confirmed by FT-IR, 1H-NMR, C-NMR and LC-MS, also, the size and charge of this compound were 128 nm and -3/68 mv respectively. MTT test showed less toxicity of the dendrimer-G2-gemifloxacin than free gemifluxacin (P < 0.001). Radiochemical yield was > %98. Human serum stability was 84% up to 24 h. Biodistribution study at 50 min, 24 and 48 h showed that the complex is significantly absorbed by the intestine and accumulation in the lungs and affects them, finally excreted through the kidneys, biodistribution results are consistent with results from full image means of SPECT/CT technique.

Human G-Protein ${\beta}3$ Subunit C825T Polymorphism is Associated with Serum Total Cholesterol and LDL-Cholesterol Levels in Koreans

  • Kang, Byung-Yong;Kang, Chin-Yang;Lee, Kang-Oh
    • Animal cells and systems
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    • v.9 no.2
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    • pp.95-100
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    • 2005
  • Essential hypertension results from the complex interaction between genetic and environmental factors. A C825T polymorphism of the gene encoding G-protein ${\beta}3$ subunit (GNB3), associated with enhanced G-protein coupled signaling and increased $Na^+-H^+$ exchanger, has been implicated in the development of essential hypertension in several human populations, especially in Caucasian population. We examined the disease relevance of this candidate gene by performing an association study in a study group of Korean heritage. Participants comprised 109 essential hypertensives and 109 normotensives, respectively. Genotyping was performed with PCR-BsaJI restriction digestion method. Observed genotype frequencies were in Hardy-Weinberg equilibrium in all groups. Genotype and allele frequencies did not differ significantly between normotensives and essential hypertensives (P>0.05). However, the serum total cholesterol (TC) and LDL-cholesterol levels were significantly higher in subjects with the TT genotype compared to those with the CC or CT genotypes in normotensives of our study subjects (P<0.05). Thus, these results suggest that GNB3/C825T polymorphism might be significantly associated with abnormality in serum lipid metabolism.

THE MANAGEMENT OF A COMPLEX IMPLANT CASE USING CAD-CAM TECHNOLOGY: A CLINICAL REPORT

  • Park, Eun-Jin
    • The Journal of Korean Academy of Prosthodontics
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    • v.46 no.6
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    • pp.634-638
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    • 2008
  • PURPOSE: The application of computer-aided technology to implant dentistry has created new opportunities for treatment planning, surgery and prosthodontic treatment, but the correct selection and combination of available methods may be challenging in times. Hence, the purpose of this case report is to present a combination of several computer-aided tools as approaches to manage complicated implant case. MATERIAL AND METHODS: A 47 year-old female patient with severe dental anxiety, high expectations, financial restrictions and poor compliance presented for a fixed rehabilitation. A CT scan with a radiographic template obtained with software (SimPlant, Materialize, Leuven, Belgium) was used for treatment planning. The surgical plan was created and converted into a stereolithographic model of the maxilla with bone-supported surgical templates (SurgiGuide, Materialise, Leuven, Belgium), that allowed for the precise placement of 7 implants in a severely resorbed edentulous maxilla. After successful osseointegration, an accurate scan model served as the basis for the fabrication of a one-piece milled titanium framework using the Procera (Nobel Biocare, Gothenburg, Sweden) technology. The final rehabilitation of the edentulous maxilla was rendered in the form of a screw-retained maxillary metal-reinforced resin-based complete prosthesis. RESULTS: Despite challenging circumstances, 7 implants could be placed without bone augmentation in a severely resorbed maxilla using the SimPlant software for pre-implant analysis and the SurgiGuide-system as the surgical template. The patient was successfully restored with a fixed full arch restoration, utilizing the Procera system for the fabrication of a milled titanium framework.

Fractal Image Coding by Linear Transformation of Computed Tomography (전산화단층촬영의 선형변환에 의한 프랙탈 영상 부호화)

  • Park, Jae-Hong;Park, Cheol-Woo
    • Journal of the Korean Society of Radiology
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    • v.11 no.4
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    • pp.241-246
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    • 2017
  • The existing fractal compression method is effective in generating an artificial shape by approximating its partial regions to a domain block by re-dividing the whole image into a domain region and dividing it into several domain blocks, but it is difficult to implement a computer. In this study, it is difficult to approximate a complex block such as a large-sized block and an affine transformation because a large amount of calculation is required in searching for a combination of similar blocks through a transformation, so a large amount of coding time is required.

SECONDARY REPAIR OF LATE ENOPHTHALMOS WITH CALVARIAL BONE GRAFTS AROUND INTRAORBITAL CONTENT -REPORT OF 2 CASES- (안와주위에 두개골이식을 통한 안구함몰의 이차적 성형재건 치험례)

  • Kim, Sung-Gil
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.20 no.4
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    • pp.373-378
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    • 1998
  • In the midfacial fracture, the orbital region presents many additional complication unique to the orbit. Among them are ectropion, entropion, lid ptosis, injury to the lacrimal apparatus, diplopia or the late development of enophthalmos. The residual problem confronting the surgen is usually enophthalmos or diplopia. Enophthalmos becomes cosmetically obvious at 3mm and if more severe it can interfere with vision from obstruction by the orbital rim. In this clinical situation, many patients prefer the simpler intraorbital volume expansion to the more complex orbital osteotomy. In general, except in mild cases of enophthalmos, the procedure of choice is osteotomy and repositioning for zygoma fracture and volume augmentation for blow-out fracture. Late treatment is performed by volume augmentation based on the CT findings behind the axis of the globe. Inferiorly placed grafts elevate the globe, posterior superior grafts move the globe anterior and medially positioned grafts push the globe laterally. In this two cases, the patients who has stable orbitozygomatic rim, the use of calvarial bone grafts more than 3 areas around intraorbital content, we corrected late enophthalmos combined with diplopia. As result, the first patient had 2mm advance in exophthalmometric check with improvement of the diplopia gradually. The second patient had 1.5mm advance with correction of vertical ocular dystopia and cosmetically good results respectively.

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Speech Interactive Agent on Car Navigation System Using Embedded ASR/DSR/TTS

  • Lee, Heung-Kyu;Kwon, Oh-Il;Ko, Han-Seok
    • Speech Sciences
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    • v.11 no.2
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    • pp.181-192
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    • 2004
  • This paper presents an efficient speech interactive agent rendering smooth car navigation and Telematics services, by employing embedded automatic speech recognition (ASR), distributed speech recognition (DSR) and text-to-speech (ITS) modules, all while enabling safe driving. A speech interactive agent is essentially a conversational tool providing command and control functions to drivers such' as enabling navigation task, audio/video manipulation, and E-commerce services through natural voice/response interactions between user and interface. While the benefits of automatic speech recognition and speech synthesizer have become well known, involved hardware resources are often limited and internal communication protocols are complex to achieve real time responses. As a result, performance degradation always exists in the embedded H/W system. To implement the speech interactive agent to accommodate the demands of user commands in real time, we propose to optimize the hardware dependent architectural codes for speed-up. In particular, we propose to provide a composite solution through memory reconfiguration and efficient arithmetic operation conversion, as well as invoking an effective out-of-vocabulary rejection algorithm, all made suitable for system operation under limited resources.

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3-Dimensional Model Simulation Craniomaxillofacial Surgery using Rapid Prototyping Technique (신속 조형 기술로 제작된 인체모형을 이용한 술전 모의 두개악안면성형수술)

  • Jung, Kyung In;Baek, Rong-Min;Lim, Joo Hwan;Park, Sung Gyu;Heo, Chan Yeong;Kim, Myung Good;Kwon, Soon Sung
    • Archives of Plastic Surgery
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    • v.32 no.6
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    • pp.796-797
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    • 2005
  • In plastic and reconstructive craniomaxillofacial surgery, careful preoperative planning is essential to get a successful outcome. Many craniomaxillofacial surgeons have used imaging modalities like conventional radiographs, computed tomography(CT) and magnetic resonance imaging(MRI) for supporting the planning process. But, there are a lot of limitations in the comprehension of the surgical anatomy with these modalities. Medical models made with rapid prototyping (RP) technique represent a new approach for preoperative planning and simulation surgery. With rapid prototyping models, surgical procedures can be simulated and performed interactively so that surgeon can get a realistic impression of complex structures before surgical intervention. The great advantage of rapid prototyping technique is the precise reproduction of objects from a 3-dimensional reconstruction image as a physical model. Craniomaxillofacial surgeon can establish treatment strategy through preoperative simulation surgery and predict the postoperative result.