• Title/Summary/Keyword: Soft Target

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3D Non-Rigid Registration for Abdominal PET-CT and MR Images Using Mutual Information and Independent Component Analysis

  • Lee, Hakjae;Chun, Jaehee;Lee, Kisung;Kim, Kyeong Min
    • IEIE Transactions on Smart Processing and Computing
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    • v.4 no.5
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    • pp.311-317
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    • 2015
  • The aim of this study is to develop a 3D registration algorithm for positron emission tomography/computed tomography (PET/CT) and magnetic resonance (MR) images acquired from independent PET/CT and MR imaging systems. Combined PET/CT images provide anatomic and functional information, and MR images have high resolution for soft tissue. With the registration technique, the strengths of each modality image can be combined to achieve higher performance in diagnosis and radiotherapy planning. The proposed method consists of two stages: normalized mutual information (NMI)-based global matching and independent component analysis (ICA)-based refinement. In global matching, the field of view of the CT and MR images are adjusted to the same size in the preprocessing step. Then, the target image is geometrically transformed, and the similarities between the two images are measured with NMI. The optimization step updates the transformation parameters to efficiently find the best matched parameter set. In the refinement stage, ICA planes from the windowed image slices are extracted and the similarity between the images is measured to determine the transformation parameters of the control points. B-spline. based freeform deformation is performed for the geometric transformation. The results show good agreement between PET/CT and MR images.

Hybrid Elastic Model for Volumetric Deformation and Real-time Haptic Simulation (볼륨 변형과 실시간 햅틱 시뮬레이션을 위한 하이브리드 탄성체 모델)

  • Cho, Jae-Hwan;Kim, Seok;Park, Jin-Ah
    • 한국HCI학회:학술대회논문집
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    • 2009.02a
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    • pp.68-73
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    • 2009
  • As various haptic algorithms and haptic equipments have developed, the computer simulation includes the haptic simulation. Basically, the haptic simulation requires very fast refresh rate approximately 1000 Hz. The traditional haptic simulations have satisfied that requirement by simplifying the target model. In soft body simulation, simplifying the deformation is not good because the visual feedback is important. Separating haptic model from deformable model can be solution of that problem. However, the user may feel a subtle distiction because the relationship between two models are not clear. In this paper, we propose the hybrid model to manipulate haptic rendering and deformation and define the relationship between two models.

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The Role of AiiA, a Quorum-Quenching Enzyme from Bacillus thuringiensis, on the Rhizosphere Competence

  • Park, Su-Jin;Park, Sun-Yang;Ryu, Choong-Min;Park, Seung-Hwan;Lee, Jung-Kee
    • Journal of Microbiology and Biotechnology
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    • v.18 no.9
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    • pp.1518-1521
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    • 2008
  • Bacteria sense their population density and coordinate the expression of target genes, including virulence factors in Gram-negative bacteria, by the N-acylhomoserine lactones (AHLs)-dependent quorum sensing (QS) mechanism. In contrast, several soil bacteria are able to interfere with QS by enzymatic degradation of AHLs, referred to as quorum quenching. A potent AHL-degrading enzyme, AiiA, from Bacillus thuringiensis has been reported to effectively attenuate the virulence of bacteria by quorum quenching. However, little is known about the role of AiiA in B. thuringiensis itself. In the present study, an aiiA-defective mutant was generated to investigate the role of AHA in rhizosphere competence in the root system of pepper. The aiiA mutant showed no detectable AHL¬-egrading activity and was less effective for suppression of soft-rot symptom caused by Erwinia carotovora on the potato slice. On the pepper root, the survival rate of the aiiA mutant significantly decreased over time compared with that of wild type. Interestingly, viable cell count analysis revealed that the bacterial number and composition of E. carotovora were not different between treatments of wild type and the aiiA mutant. These results provide evidence that AHA can play an important role in rhizosphere competentce of B. thuringiensis and bacterial quorum quenching to Gram-negative bacteria without changing bacterial number or composition.

AI-based Automatic Spine CT Image Segmentation and Haptic Rendering for Spinal Needle Insertion Simulator (척추 바늘 삽입술 시뮬레이터 개발을 위한 인공지능 기반 척추 CT 이미지 자동분할 및 햅틱 렌더링)

  • Park, Ikjong;Kim, Keehoon;Choi, Gun;Chung, Wan Kyun
    • The Journal of Korea Robotics Society
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    • v.15 no.4
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    • pp.316-322
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    • 2020
  • Endoscopic spine surgery is an advanced surgical technique for spinal surgery since it minimizes skin incision, muscle damage, and blood loss compared to open surgery. It requires, however, accurate positioning of an endoscope to avoid spinal nerves and to locate the endoscope near the target disk. Before the insertion of the endoscope, a guide needle is inserted to guide it. Also, the result of the surgery highly depends on the surgeons' experience and the patients' CT or MRI images. Thus, for the training, a number of haptic simulators for spinal needle insertion have been developed. But, still, it is difficult to be used in the medical field practically because previous studies require manual segmentation of vertebrae from CT images, and interaction force between the needle and soft tissue has not been considered carefully. This paper proposes AI-based automatic vertebrae CT-image segmentation and haptic rendering method using the proposed need-tissue interaction model. For the segmentation, U-net structure was implemented and the accuracy was 93% in pixel and 88% in IoU. The needle-tissue interaction model including puncture force and friction force was implemented for haptic rendering in the proposed spinal needle insertion simulator.

Ultrasonography of the Elbow Joint (주관절의 초음파 검사)

  • Kim, Chul Hong;Lee, Myung Jin;Kang, Min Soo
    • The Journal of Korean Orthopaedic Ultrasound Society
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    • v.5 no.2
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    • pp.123-129
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    • 2012
  • The purpose of this article is review about the use of ultrasonography in the evaluation of the elbow joint. Ultrasonography has several key advantages in elbow joint, including easy assessment of target structure in elbow joint and ability to perform real time dynamic examination and to compare with opposite site. Ultrasonography is easy available to visualize abnormalities affecting tendons, muscles, ligaments, bursae, and occult fractures around the elbow joint and also allows accurate assessment of ulnar nerve in cubital tunnel. The role of ultrasonography will increase further with regards to evaluation of soft-tissue abnormalities of the elbow joint.

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Construction of Korea Space Weather Prediction Center: VHF Coherent Scatter Radar

  • Hwang, Jung-A;Kwak, Young-Sil;Cho, Kyung-Suk;Kim, Khan-Hyuk;Park, Young-Deuk
    • Bulletin of the Korean Space Science Society
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    • 2008.10a
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    • pp.32.4-33
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    • 2008
  • Korea space weather prediction center (KSWPC) in Korea Astronomy and Space Science Institute (KASI) has been constructing several facilities to observe mid- to low-latitude upper atmospheric/ionospheric phenomena; VHF coherent scattering radar, All-sky Imager, and Scintmon. Those new ionospheric facilities can be integrated to produce more reliable space weather forecast and nowcast with the existing facilities; Solar Flare Telescope (SOFT), Solar Optical Observatory's sunspot telescope and solar imaging spectrograph, and Magnetometer. The specification of KASI VHF coherent scattering radar is 40.8 MHz of target frequency, 200 kHz of bandwidth, 24 kW of peak power. The science goal of this radar is to measure the irregularities in E- and F-layers over Korea, especially sporadic-E, spread-F, and traveling ionospheric disturbance (TID). The radar will be installed at Gyerong in a territory of Korean Air force by early 2009.

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Minimum Expected Cost based Design of Vertical Drain Systems (최소기대비용에 의한 연직배수시설의 설계)

  • Kim, Seong-Pil;Son, Young-Hwan;Chang, Pyung-Wook
    • Journal of The Korean Society of Agricultural Engineers
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    • v.49 no.6
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    • pp.93-101
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    • 2007
  • In general, geotechnical properties have many uncertain aspects, thus probabilistic analysis have been used to consider these aspects. It is, however, quite difficult to select an appropriate target probability for a certain structure or construction process. In this study, minimum expected cost design method based on probabilistic analysis is suggested for design of vertical drains generally used to accelerate consolidation in soft clayey soils. A sensitivity analysis is performed to select the most important uncertain parameters for the design of vertical drains. Monte Carlo simulation is used in sensitivity analysis and probabilistic analysis. Total expected cost, defined as the sum of initial cost and expected additive cost, varies widely with variation of input parameters used in design of vertical drain systems. And probability of failure to get the minimum total expected cost varies under the different design conditions. A minimum value of total expected cost is suggested as a design value in this study. The proposed design concept is applicable to unit construction process because this approach is to consider the uncertainties using probabilistic analysis and uncertainties of geotechnical properties.

Pulse-to-Pulse Coding for Channel Interference Suppression of Short Range Radar for GVES (지상 기동 장비용 근거리 레이더의 채널 간섭 억제를 위한 펄스간 코딩 연구)

  • Park, Gyu-Churl;Ha, Jong-Soo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.9
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    • pp.883-889
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    • 2009
  • Since the SRRs(Short Range Radar) load on the GVESs(Ground Vehicle Equipment System) are operated within several hundred meters, it is important to suppress the interferences between the SRRs. These interference are reduced using the frequency separation between channels, however this method isn't a perfect solution owing to a difficulty of a realization for the interference suppression. Thus, a pulse-to-pulse coding used to suppress the interference fundamentally is proposed in this paper. The concept, the application method and the test results of the proposed method have been described in this paper.

A Survey of Actual Guides for Children to Take the Oriental Medicine in the Oriental Clinics & the Oriental Hospitals (한의원과 한방병원에서 행해지고 있는 소아에 대한 한약복약지도 현황 조사 연구)

  • Lee, Su Jeong;Lee, Seung Yeon;Yu, Sun Ae
    • The Journal of Pediatrics of Korean Medicine
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    • v.27 no.3
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    • pp.12-19
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    • 2013
  • Objectives Children's unique taste bud often gives them difficult time to take oriental medicines. To overcome, survey was conducted focusing on useful and practical tips on how to take them. Methods The survey was carried out by posting mail questionnaire. Target clinics for the survey were selected by the internet search engine, Google, Daum, and Naver, and typing in "oriental treatment + pediatrics", "pediatrics + oriental medicine", "pediatric oriental clinic". 24 clinics were searched, but they were further narrowed down to the specialized pediatric oriental clinics. Also, total of 38 inquiry leaflets were distributed to 14 University Oriental Hospitals. Results If children refuse to take the medicine, mixture with sweeteners can be prescribed for them. Among them, oligosaccharide is the most recommended followed by sugar and honey. To avoid rejection to medication, use of different formulation, such as distillation medicine, soft X-Section, granulated medicine, and character printing can be used. Conclusions The most effective method is to investigate the mixture first, and then the alternative formulations.

Advanced Imaging Applications for Locally Advanced Cervical Cancer

  • Petsuksiri, Janjira;Jaishuen, Atthapon;Pattaranutaporn, Pittayapoom;Chansilpa, Yaowalak
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.5
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    • pp.1713-1718
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    • 2012
  • Advanced imaging approaches (computed tomography, CT; magnetic resonance imaging, MRI; $^{18}F$-fluorodeoxyglucose positron emission tomography, FDG PET) have increased roles in cervical cancer staging and management. The recent FIGO (International Federation of Gynecology and Obstetrics) recommendations encouraged applications to assess the clinical extension of tumors rather than relying on clinical examinations and traditional non-cross sectional investigations. MRI appears to be better than CT for primary tumors and adjacent soft tissue involvement in the pelvis. FDG-PET/CT has increased in usage with a particular benefit for whole body evaluation of tumor metabolic activity. The potential benefits of advanced imaging are assisting selection of treatment based upon actual disease extent, to adequately treat a tumor with minimal normal tissue complications, and to predict the treatment outcomes. Furthermore, sophisticated external radiation treatment and brachytherapy absolutely require advanced imaging for target localization and radiation dose calculation.