• Title/Summary/Keyword: Region Growing Method

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A Novel Method for Automated Honeycomb Segmentation in HRCT Using Pathology-specific Morphological Analysis (병리특이적 형태분석 기법을 이용한 HRCT 영상에서의 새로운 봉와양폐 자동 분할 방법)

  • Kim, Young Jae;Kim, Tae Yun;Lee, Seung Hyun;Kim, Kwang Gi;Kim, Jong Hyo
    • KIPS Transactions on Software and Data Engineering
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    • v.1 no.2
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    • pp.109-114
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    • 2012
  • Honeycombs are dense structures that small cysts, which generally have about 2~10 mm in diameter, are surrounded by the wall of fibrosis. When honeycomb is found in the patients, the incidence of acute exacerbation is generally very high. Thus, the observation and quantitative measurement of honeycomb are considered as a significant marker for clinical diagnosis. In this point of view, we propose an automatic segmentation method using morphological image processing and assessment of the degree of clustering techniques. Firstly, image noises were removed by the Gaussian filtering and then a morphological dilation method was applied to segment lung regions. Secondly, honeycomb cyst candidates were detected through the 8-neighborhood pixel exploration, and then non-cyst regions were removed using the region growing method and wall pattern testing. Lastly, final honeycomb regions were segmented through the extraction of dense regions which are consisted of two or more cysts using cluster analysis. The proposed method applied to 80 High resolution computed tomography (HRCT) images and achieved a sensitivity of 89.4% and PPV (Positive Predictive Value) of 72.2%.

Study of CO2 Absorption in Forest by Airborn LiDAR Data (LiDAR 자료를 이용한 산림 CO2 흡수량 산출 연구)

  • Go, Sin Young;Park, Jung Gi;Cho, Gi Sung
    • Journal of Korean Society for Geospatial Information Science
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    • v.21 no.4
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    • pp.29-35
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    • 2013
  • Generally, Calculation of carbon dioxide absorption in the forest area is calculated using the information of the forest, such as tree height and DBH(Diameter of Breast Height). Tree height and DBH of these are obtained using the remote sensing data such as imagery and information of local forest survey. However, Mixed forest with a high proportion of field survey to lower the accuracy of forest information. In this study, vertical structure of the tree were identified by applying region growing method based on the slope using LiDAR data and height and number of the tree were identified by applying extracting top of the tree algorithm. Through the vertex tree extraction algorithm to identify height of tree and the number of individuals, substitute this for the DBH relation formula which is drawn from data through field surveys. In this, a quantitative calculation of carbon dioxide absorption were able to calculate the basic data. Also, carbon dioxide absorption of three type trees were calculated and average per unit area of carbon dioxide absorption were able to estimate.

Incidence of Cancers in Kuzestan Province of Iran: Trend from 2004 to 2008

  • Amoori, Neda;Mirzaei, Masoud;Cheraghi, Maria
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.19
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    • pp.8345-8349
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    • 2014
  • Background: Cancer is an increasing cause of mortality and morbidity worldwide. Incidences of common cancers has been growing in different provinces of Iran in recent years but trends in Khuzestan which shares a border with Iraq and is located in south west of Iran have not been investigated. This study aimed to assess secular changes in incidences of common cancers in Khuzestan province from 2004 to 2008. Materials and Methods: Data were collected from Khuzestan cancer registry which is a branch of Iranian Ministry of Health Cancer Registry (http://ircancer.ir) for the period 2004-2008. Data were presented as incidence rates by site, sex, age, using the crude rate and age-standardized rate (ASR) per $10^5$ persons. A direct method of standardization was applied according to the WHO guideline and data analysis was performed using the SPSS package. Results: During the 2004-2008 period, 14,893 new cases of cancer were registered in Khuzestan cancer registry. The age-standardized incidence rate of all cancers was 153.7 per $10^5$ in males and 156.4 per $10^5$ in females. The incidence was increased over the period of five years. The most incident cancers among males were skin cancer ($ASR=18.7/10^5$), stomach cancer ($ASR13.8/10^5$), lung cancer ($ASR12.9/10^5$), leukemia ($ASR=12.6/10^5$) and prostate cancer ($ASR=12.4/10^5$). In females, the most incident cancers were breast cancer ($ASR=41/10^5$), skin cancer ($ASR=16.4/10^5$), colorectal cancer ($ASR=10.0/10^5$), leukemia ($ASR=8.1/10^5$) and lung cancer ($ASR=6.9/10^5$). Conclusions: Incidences of various cancers are rising in Khuzestan. It is necessary to develop and implement comprehensive cancer control programs in this region which could be monitored and evaluated by the future trend data from Khuzestan cancer registry.

Development and Usability Testing of a User-Centered 3D Virtual Liver Surgery Planning System

  • Yang, Xiaopeng;Yu, Hee Chul;Choi, Younggeun;Yang, Jae Do;Cho, Baik Hwan;You, Heecheon
    • Journal of the Ergonomics Society of Korea
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    • v.36 no.1
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    • pp.37-52
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    • 2017
  • Objective: The present study developed a user-centered 3D virtual liver surgery planning (VLSP) system called Dr. Liver to provide preoperative information for safe and rational surgery. Background: Preoperative 3D VLSP is needed for patients' safety in liver surgery. Existing systems either do not provide functions specialized for liver surgery planning or do not provide functions for cross-check of the accuracy of analysis results. Method: Use scenarios of Dr. Liver were developed through literature review, benchmarking, and interviews with surgeons. User interfaces of Dr. Liver with various user-friendly features (e.g., context-sensitive hotkey menu and 3D view navigation box) was designed. Novel image processing algorithms (e.g., hybrid semi-automatic algorithm for liver extraction and customized region growing algorithm for vessel extraction) were developed for accurate and efficient liver surgery planning. Usability problems of a preliminary version of Dr. Liver were identified by surgeons and system developers and then design changes were made to resolve the identified usability problems. Results: A usability testing showed that the revised version of Dr. Liver achieved a high level of satisfaction ($6.1{\pm}0.8$ out of 7) and an acceptable time efficiency ($26.7{\pm}0.9 min$) in liver surgery planning. Conclusion: Involvement of usability testing in system development process from the beginning is useful to identify potential usability problems to improve for shortening system development period and cost. Application: The development and evaluation process of Dr. Liver in this study can be referred in designing a user-centered system.

Computational Analysis of Tumor Angiogenesis Patterns Using a Growing Brain Tumor Model

  • Shim, Eun-Bo;Kwon, Young-Keun;Ko, Hyung-Jong
    • International Journal of Vascular Biomedical Engineering
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    • v.2 no.1
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    • pp.17-24
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    • 2004
  • Tumor angiogenesis was simulated using a two-dimensional computational model. The equation that governed angiogenesis comprised a tumor angiogenesis factor (TAF) conservation equation in time and space, which was solved numerically using the Galerkin finite element method. The time derivative in the equation was approximated by a forward Euler scheme. A stochastic process model was used to simulate vessel formation and vessel elongation towards a paracrine site, i.e., tumor-secreted basic fibroblast growth factor (bFGF). In this study, we assumed a two-dimensional model that represented a thin (1.0 mm) slice of the tumor. The growth of the tumor over time was modeled according to the dynamic value of bFGF secreted within the tumor. The data used for the model were based on a previously reported model of a brain tumor in which four distinct stages (namely multicellular spherical, first detectable lesion, diagnosis, and death of the virtual patient) were modeled. In our study, computation was not continued beyond the 'diagnosis' time point to avoid the computational complexity of analyzing numerous vascular branches. The numerical solutions revealed that no bFGF remained within the region in which vessels developed, owing to the uptake of bFGF by endothelial cells. Consequently, a sharp, declining gradient of bFGF existed near the surface of the tumor. The vascular architecture developed numerous branches close to the tumor surface (the brush-border effect). Asymmetrical tumor growth was associated with a greater degree of branching at the tumor surface.

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Isocenter Verification Using Linac-Gram Films Taken with Angiolocalizer : Improved Quality Assurance of Fractionated Stereotactic Radiation Therapy(FSRT) (Angiolocalizer를 사용하여 얻어진 Linac-Gram을 이용한 조사야 중심의 정확도 평가 (FSRT의 진보된 Quality Assurance))

  • Cho, Jung-Keun;Park, Young-Hwan;Ju, Sang-Kyu;Kim, Young-Gon;Cho, Hyun-Sang
    • The Journal of Korean Society for Radiation Therapy
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    • v.9 no.1
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    • pp.25-28
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    • 1997
  • With the advances in radiation therapy technology and equipment, the need for more accurate and safer radiation delivery to the target region has been continuously growing. Stereotactic Radiosurgery(SRS) is a good example of $^{\ast}Accuracy^{\ast}$ but has a substantial risk of causing severe late neurological damages. Fractionated Stereotactic Radiation Therapy(FSRT) is a modification of SRS enabling conventional fractionation with maintaining accuracy using noninvasive and relocatable frame. Verification of mechanical accuracy in FSRT has been done according to the manufacture's recommendations using RLPP, LTLF, and Depth-helmet. In order to reinforce this, we have developed additional novel verification procedure using Linac-grams with the Angiolocalizer attached on the GTC frame, which are then digitized into the planning software(X-Knife) to generate the three dimensional coordinates for cmoparison. This method has been successful in such ways that the anatomical landmarks are identifiable on the Linac-gram films and that the serial comparisons of the stereotactic coordinates of the isocenter are possible with more certainty a along the FSRT course than before.

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Contaminant transport through porous media: An overview of experimental and numerical studies

  • Patil, S.B.;Chore, H.S.
    • Advances in environmental research
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    • v.3 no.1
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    • pp.45-69
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    • 2014
  • The groundwater has been a major source of water supply throughout the ages. Around 50% of the rural as well as urban population in the developing countries like India depends on groundwater for drinking. The groundwater is also an important source in the agriculture and industrial sector. In many parts of the world, groundwater resources are under increasing threat from growing demands, wasteful use and contamination. A good planning and management practices are needed to face this challenge. A key to the management of groundwater is the ability to model the movement of fluids and contaminants in the subsurface environment. It is obvious that the contaminant source activities cannot be completely eliminated and perhaps our water bodies will continue to serve as receptors of vast quantities of waste. In such a scenario, the goal of water quality protection efforts must necessarily be the control and management of these sources to ensure that released pollutants will be sufficiently attenuated within the region of interest and the quality of water at points of withdrawal is not impaired. In order to understand the behaviour of contaminant transport through different types of media, several researchers are carrying out experimental investigations through laboratory and field studies. Many of them are working on the analytical and numerical studies to simulate the movement of contaminants in soil and groundwater of the contaminant transport. With the advent of high power computers especially, a numerical modelling has gained popularity and is indeed of particular relevance in this regard. This paper provides the state of the art of contaminant transport and reviews the allied research works carried out through experimental investigation or using the analytical solution and numerical method. The review involves the investigation in respect of both, saturated and unsaturated, porous media.

Preliminary Leak-before Break Assessment of Intermediate Heat Transport System Hot-Leg of a Prototype Generation IV Sodium-cooled Fast Reactor (소듐냉각고속로 원형로 중간열전달계통 고온배관의 파단전누설 예비평가)

  • Lee, Sa Yong;Kim, Nak Hyun;Koo, Gyeong Hoi;Kim, Sung Kyun;Kim, Yoon Jea
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.12 no.1
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    • pp.126-133
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    • 2016
  • Recently, the research and development of Sodium-cooled Fast Reactors (SFRs) have made progresses. However, liquid sodium, the coolant of an SFR, is chemically unstable and sodium fire can be occurred when liquid sodium leaks from sodium pipe. To reduce the damage by the sodium fire, many fire walls and fire extinguishers are needed for SFRs. LBB concept in SFR might reduce the scale of sodium fire and decrease or eliminate fire walls and fire extinguishers. Therefore, LBB concept can contribute to improve economic efficiency and to strengthen defense-in depth safety. The LBB assessment procedure has been well established, and has been used significantly in light water reactors (LWRs). However, an LBB assessment of an SFR is more complicated because SFRs are operated in elevated temperature regions. In such a region, because creep damage may occur in a material, thereby growing defects, an LBB assessment of an SFR should consider elevated temperature effects. The procedure and method for this purpose are provided in RCC-MRx A16, which is a French code. In this study, LBB assessment was performed for PGSFR IHTS hot-leg pipe according to RCC-MRx A16 and the applicability of the code was discussed.

Factors That Affect Family Planning of Fertile Women in Volta Region in Ghana (가나 볼타지역 가임여성의 가족계획 실천에 영향을 미치는 요인)

  • Kim, Jae Woo;Nam, Eun Woo
    • Health Policy and Management
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    • v.24 no.4
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    • pp.389-395
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    • 2014
  • Background: Family planning is widely practiced today to resolve the over-growing population and overcome obstacles that thwart socio-economic growth. While Ghana was the first country in Africa to implement family planning program, its birthrate is still twice as much as world average due to weak infrastructure and strategic plans to enforce the policy. Thus, there is a need to objectively verify the factors that affect family planning of fertile women of Ghana. Methods: Total of 630 self-administered questionnaires were distributed from April 8 to 17 of 2013 to collect data. Six-hundred eighteen questionnaires were analyzed, excluding the 12 incomplete questionnaires. Collected data were analyzed using PASW SPSS ver. 18, and logistic regression analysis was performed to verify the factors that affect practice of family planning. Results: Satisfaction with health and medical facilities, experience with family planning education and awareness of birth control methods significantly affected practice of family planning. Based on analysis using odds ratio, enforcement rate of family planning increased by 4.574 times when the subjects were satisfied with health and medical facilities, by 3.920 times when received family planning education, and by 3.284 times when they were aware of birth control methods. Conclusion: By adopting family planning education program, government should be able to change fertile women's perception of family planning. A strategic plan is necessary in order to increase access to medical facilities, improve service satisfaction, and induce women to enforce family planning voluntarily.

Automatic Detection of Initial Positions for Mass Segmentation in Digital Mammograms (디지털 마모그램에서 Mass형 유방암 분할을 위한 초기 위치 자동 검출)

  • Lee, Bong-Ryul;Lee, Myeong-Jin
    • Journal of Korea Multimedia Society
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    • v.13 no.5
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    • pp.702-709
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    • 2010
  • The performance of mass segmentation is greatly influenced by an initial position of a mass. Some researchers performed mass segmentation with the initial position of a mass given by radiologists. The purpose of our research is to find the initial position for mass segmentation and to notify the segmented mass to radiologists without any additional information on mammograms. The proposed system consists of breast segmentation by region growing and opening operations, decision of an initial seed with characteristics of masses, and mass segmentation by a level set segmentation. A seed for mass segmentation is set based on mass scoring measure calculated by block-based variances and masked information in a sub-sampled mammogram. We used a DDSM database to evaluate the system. The accuracy of mass detection is 78% sensitivity at 4 FP/image, and it reached 92% if multiple views for masses were considered.