• Title/Summary/Keyword: Local watershed

Search Result 148, Processing Time 0.024 seconds

Microcalcification Detection Based on Region Growing Method with Contrast and Edge Sharpness in Digital X-ray Mammographic Images (명암 대비와 에지 선예도를 이용하는 영역 성장법에 의한 디지털 X선 맘모그램 영상에서의 미세 석회화 검출)

  • Won, C.H.;Kang, S.W.;Cho, J.H.
    • Journal of Sensor Science and Technology
    • /
    • v.13 no.1
    • /
    • pp.56-65
    • /
    • 2004
  • In this paper, we proposed the detection algorithm of microcalcification based on region growing method with contrast and edge sharpness in digital X-ray mammographic images. We extracted the local maximum pixel and watershed regions by using watershed algorithm. Then, we used the mean slope between local maximum and neighborhood pixels to extract microcalcification candidate pixels among local maximum pixels. During increasing threshold value to grow microcalcification region, at the maximum threshold value of the contrast and edge sharpness, the microcalcification area is decided. The regions of which area of grown candidate microcalfication region is larger than that of watershed region are excluded from microcalcifications. We showed the diagnosis algorithm can be used to aid diagnostic-radiologist in the early detection breast cancer.

Color Image Enhancement Using Local Area Histogram Equalization On Segmented Regions Via Watershed Transform

  • Lertpokanont, B.;Chitwong, S.;Cheevasuvit, F.;Dejhan, K.
    • Proceedings of the KSRS Conference
    • /
    • 2003.11a
    • /
    • pp.192-194
    • /
    • 2003
  • Since the details in quasi-homogeneous region will be destroyed from the conventional global image enhancement method such as histogram equalization. This defect is caused by the saturation of gray level in equalization process. So the local histogram equalization for each quasi-homogeneous region will be used in order to improve the details in the region itself. To obtain the quasi- homogeneous regions, the original image must be segmented. Here we applied the watershed transform to the interesting image. Since the watershed transform is based on mathematical morphology, therefore, the regions touch can be effectively separated. Hence two adjacent regions which have the similar gray pixels will be split off. The process will be independently applied to three different spectral images. Then three different colors are assigned to each processed image in order to produce a color composite image. By the proposed algorithm, the result image shows the better perception on image details. Therefore, the high efficiency of image classification can be obtained by using this color image.

  • PDF

Using GIS Spatial Analysis to Protect Critical Habitats in the Big Cyprus Watershed, South Florida (GIS 공간분석을 통한 남부 플로리다 Big Cyprus 분수계 보존서식지 보호)

  • Kim, Jin-Ho;Kim, Chang-Ho;Kim, Hyun-Woo
    • Journal of KIBIM
    • /
    • v.7 no.4
    • /
    • pp.31-38
    • /
    • 2017
  • Big Cyprus watershed, which is located in the Southwestern Florida and covers Everglades National Park that has high proportions of endangered species' habitats, plays an important role for the entire Florida ecosystem. Due to the rapid urbanization and high population growth, however, the watershed has been continuously polluted and the current regional watershed plan is not created to accommodate the speed of growth. The purpose of this study is to suggest proper protection policies and strategies for the Big Cyprus watershed by employing the Inverse Distance Weighted interpolation tool in Geographic Information System. The findings show that conservation priorities should be given in the North and South portion of the watershed area, which are proven to be the most important aisle for the habitats in the Big Cyprus. The study concludes with policy suggestions that local environmental planners should concentrate for adopting their new watershed plan in the near future.

A Study on the Inquiry-Based Water Environmental Education Model with Watershed Concept: Focusing on the ENVISION Program (유역 개념을 중심으로 한 탐구 기반의 물 환경교육 모형에 관한 연구: ENVISION 프로그램을 중심으로)

  • Lee, Du-Gon
    • Hwankyungkyoyuk
    • /
    • v.19 no.3
    • /
    • pp.150-164
    • /
    • 2006
  • This study reviewed a recently developed environmental education model 'ENVISION' and analyzed the value of the ENVISION program with environmental education(EE) perspective. Also this study proposed a prototype model of a inquiry-based water environmental education model with watershed concepts as a result of discussion of tills research. In the review of ENVISION, this research followed the theoretical framework of 'Inquiry-Based EE' that was previously proposed by the author. The ENVISION was characterized in tills research as two directions: watershed and scientific inquiry. Tills research argued that the watershed concept has a potentially very good meaning in EE because watershed enables 'holistic' view in EE area, and that the scientific inquiry in ENVISION seeks evidence-based explanation about local watershed environmental problems. That belongs to the scientific inquiry, which is also 'Inquiry-Based EE' and has internal value under EE perspective. Finally, this research proposed a prototype EE model that is about watershed concept, and is based on inquiry as general sense (scientific and insightful inquiries) and 'Environmental Studies for EE, (ESEE)' as the inquiry directions. The proposed model can be said a combination of the watershed concept and inquiry-based EE, and it seems that the model materializes better the EE nature than the ENVISION model.

  • PDF

Analysis of Impact of Climate Change on River Flows in an Agricultural Watershed Using a Semi-distributed Watershed Model STREAM (준분포형 유역모델 STREAM을 이용한 기후변화가 농업유역의 하천유량에 미치는 영향 분석)

  • Jeong, Euisang;Cho, Hong-Lae
    • Journal of Korean Society on Water Environment
    • /
    • v.35 no.2
    • /
    • pp.131-144
    • /
    • 2019
  • Climate Change affects the hydrological cycle in agricultural watersheds through rising air temperature and changing rainfall patterns. Agricultural watersheds in Korea are characterized by extensive paddy fields and intensive water use, a resource that is under stress from the changing climate. This study analyzed the effects of climate change on river flows for Geum Cheon and Eun-San Choen watershed using STREAM, a semi-distributed watershed model. In order to evaluate the performance and improve the reliability of the model, calibration and validation of the model was done for one flow observation point and three reservoir water storage ratio points. Climate change scenarios were based on RCP data provided by the Korea Meteorological Administration (KMA) and bias corrections were done using the Quantile Mapping method to minimize the uncertainties in the results produced by the climate model to the local scale. Because of water mass-balance, evapotranspiration tended to increase steadily with an increase in air temperature, while the increase in RCP 8.5 scenario resulted in higher RCP 4.5 scenario. The increase in evapotranspiration led to a decrease in the river flow, particularly the decrease in the surface runoff. In the paddy agricultural watershed, irrigation water demand is expected to increase despite an increase in rainfall owing to the high evapotranspiration rates occasioned by climate change.

Application of BASINS for the water quality prediction in rural watersheds - on HSPF model - (농촌유역의 수질예측을 위한 BASINS의 적용 - HSPF모형을 중심으로 -)

  • Ham, Jong-Hwa;Yoon, Chun-Gyeong
    • Proceedings of the Korean Society of Agricultural Engineers Conference
    • /
    • 2001.10a
    • /
    • pp.403-407
    • /
    • 2001
  • For the water quality management of stream and lake, it is important to estimate and control nonpoint source loading to meet the water quality standard. So, integrated watershed management is required. BASINS is a multipurpose environmental analysis system for use by regional, state, and local agencies in performing watershed and water quality based studies. BASINS was developed by the USEPA to facilitate examination of environmental information, to support analysis of environmental systems and to provide a framework for examining management alternatives. BASINS contains HSPF which is one of the watershed runoff model. By using HSPF, nonpoint source loading from upper stream watershed was estimated. As a result, the simulated runoff was in a good agreement with the observed data and indicated reasonable applicability for whole watershed.

  • PDF

Public Perceptions and Support of Environmental Management in the Source Area of Drinking Water for Beijing, China

  • Wang, Xiaoyan;Feng, Qing;Zhang, Yafan;Duan, Shuhuai;Novotny, Vladimir
    • Environmental Engineering Research
    • /
    • v.15 no.1
    • /
    • pp.49-56
    • /
    • 2010
  • Based on a survey of citizens and data analysis on the environmental status of the Miyun Reservoir watershed, China, the environmental awareness of citizens residing in the watershed and the impacting factors are discussed. The contingent valuation method was used to evaluate the willingness of villagers to pay (WTP) for abatement of the rural domestic pollution and to assess the intensity level of the villagers' desire for improving environmental conditions in the Miyun Reservoir watershed. It was found that rural watershed residents had a fundamental cognitive understanding of the pollution status and protection measures of the Miyun Reservoir. However, based on the survey, local residents had only a small interest in their participation to improve the environmental status of the reservoir, despite their general attitude to protect the reservoir being very positive. Gender and family income were closely associated with the overall attitudes of the population. Public media are the most preferable means for conveying knowledge of environmental protection to people living in the watershed. Increasing the educational level, along with income, are the best ways to enhance the desire of the villagers to improve the environmental quality and management.

Evaluation and improvement of forest watershed management projects in Korea

  • Rhee, Hakjun
    • Korean Journal of Agricultural Science
    • /
    • v.47 no.4
    • /
    • pp.885-901
    • /
    • 2020
  • A forest watershed management project was introduced in 2004 to develop ecologically sound forest watersheds. It includes landslide prevention and erosion control, water resource management, landscape development, and forest resource management. However, it has been managed fragmentarily and inefficiently, far from the original intents. This study investigated current status, problems, and improvement measures of the project. Literature reviews were conducted on forest watershed management in Korea and other countries, and surveys were conducted on 201 erosion control experts. When introduced, the forest watershed management project was well planned and implemented as intended. It later turned to focus only on disaster prevention such as erosion control dams and stream conservation measures. The survey results showed that a majority (89% and 86%) of surveyees wanted increases in the project period and budget. They also responded that conflicts with local residents (51%) and determining project locations (32%) were the most difficult tasks when implementing the projects, and only 36% kept project records. To plan and implement the projects as intended, the following suggestions should be considered: (1) establishment of a solid legal foundation and improvement of the erosion control practices law; (2) increase in the project period (from 1 to 2 - 3 years) and budget; (3) development of a manual for project site selection and guidelines; (4) monitoring and systematic information management; and (5) development of spatial analysis tools for watershed analysis and management.

COUNTING OF FLOWERS BASED ON K-MEANS CLUSTERING AND WATERSHED SEGMENTATION

  • PAN ZHAO;BYEONG-CHUN SHIN
    • Journal of the Korean Society for Industrial and Applied Mathematics
    • /
    • v.27 no.2
    • /
    • pp.146-159
    • /
    • 2023
  • This paper proposes a hybrid algorithm combining K-means clustering and watershed algorithms for flower segmentation and counting. We use the K-means clustering algorithm to obtain the main colors in a complex background according to the cluster centers and then take a color space transformation to extract pixel values for the hue, saturation, and value of flower color. Next, we apply the threshold segmentation technique to segment flowers precisely and obtain the binary image of flowers. Based on this, we take the Euclidean distance transformation to obtain the distance map and apply it to find the local maxima of the connected components. Afterward, the proposed algorithm adaptively determines a minimum distance between each peak and apply it to label connected components using the watershed segmentation with eight-connectivity. On a dataset of 30 images, the test results reveal that the proposed method is more efficient and precise for the counting of overlapped flowers ignoring the degree of overlap, number of overlap, and relatively irregular shape.

Development of Water Environmental Education Program Using Streams - Focused on ENVISION - (소하천 물 환경교육 프로그램 개발 - ENVISION을 중심으로 -)

  • Kim, Jeong-Hwa;Lee, Du-Gon
    • Hwankyungkyoyuk
    • /
    • v.20 no.4
    • /
    • pp.12-26
    • /
    • 2007
  • The purpose of this research is to develop a water environmental education (EE) program using streams, based on the core ideas of ENVISION and materializing elements that were extracted in this research. This research realized the elements and presented a model of the water EE program using a local stream. First, this research developed a basic model of a water EE program using streams by extracting 10 materializing elements and realizing the elements in 4 stage-procedural model. The 10 materializing elements were 1. experiencing the process of inquiry, 2. inquiring local environments, 3. self-directing learning and mutual interaction with colleagues, 4. collecting real data and interpreting, 5. utilizing the ICT(information and communication technology), 6. inquiring with the view point of the 'Environmental Studies for EE', 7. inquiring with the watershed concept, 8. inquiring with the integrating and the holistic view point, 9. pursuing the macroscopic understanding about environment, and 10. connecting the real world phenomena with the environmental concepts and theories. This research materialized these 10 elements in 4 stage model, following the previous ENVISION research, which are 1. preparing stage and visual assessment, 2. writing the report of the inquiry plan, 3. collecting the real data in the environment and performing the investigation, and 4. presenting the inquiry results. Second, with using this basic model, this research developed and presented a model of the specific water EE program using a case stream called 'Baig Cheon' stream, which is a local stream. This research is considered to have a considerable meaning in developing a EE program with ENVISION ideas for the watershed concept and inquiry with environmental science using local streams. The developed model can help the professional development of teachers and teacher education of water EE.

  • PDF