• Title/Summary/Keyword: flow information

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Distributed GIS-Based Watershed Rainfall-Runoff Model Development and Its Calibration using Weather Radar (기상레이더와 지형정보시스템을 이용한 분포형 강우-유출 유역모형의 개발과 검정)

  • Skahill, Brian E.;Choi, Woo-Hee;Kim, Min-Hwan;Kim, Sung-Kyun;Johnson, Lynn E.
    • Journal of Korea Water Resources Association
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    • v.36 no.2
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    • pp.285-300
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    • 2003
  • An event-based, kinematic, infiltration-excess, and distributed rainfall-runoff model using weather radar and Geographic Information System(GIS) was developed to acknowledge and account lot the spatial variability and uncertainty of several parameters relevant to storm surface runoff and surface flow The developed model is compatible with raster GIS and spatially and temporally varied rainfall data. To calibrate the model, Monte Carlo simulation and a likelihood measure are utilized; allowing for a range of possible system responses from the calibrated model. Using rain gauge adjusted radar-rainfall estimates, the developed model was applied and evaluated to a limited number of historical events for the Ralston Creek and Goldsmith Gulch basins within the Denver Urban Drainage and Flood Control District (UDFCD) that contain mixed land use classifications. While based on a limited number of Monte Carlo simulations and considered flood events, Nash and Sutcliffe efficiency score ranges of -0.19∼0.95 / -0.75∼0.81 were obtained from the calibrated models for the Ralston Creek and Goldsmith Gulch basins, based on a comparison of observed and simulated hydrographs. For the Ralston Creek and Goldsmith Gulch basins, Nash and Sutcliffe efficiency scores of 0.88/0.10, 0.14/0.71, and 0.99/0.95 for runoff volume, peak discharge, and time to peak, respectively, were obtained from the model.

Biogeochemical Reactions in Hyporheic Zone as an Ecological Hotspot in Natural Streams (자연 하천의 생태학적 중요 지점으로서 지표수-지하수 혼합대의 생지화학적 기작)

  • Kim, Young-Joo;Kang, Ho-Jeong
    • Journal of Wetlands Research
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    • v.11 no.1
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    • pp.123-130
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    • 2009
  • Hyporheic zone is an area where hydraulic exchanges occur between surface water and ground water. Such transient area is anticipated to facilitate diverse biogeochemical reactions by providing habitats for various microorganism. However, only a few data are available about microbial properties in hyporheic zone, which would be important in better understanding of biogeochemical reactions in whole streams. The study site is Naesung stream, located in the north Kyoung-Sang Province, of which sediment is sandy with little anthropogenic impacts. Soil samples were collected from a transect placed perpendicular to stream flow. The transect includes upland fringe area dominated by Phragmites japonica, bare soil, and soil adjacent to water. In addition, soil samples were also collected from downwelling and upwelling areas in hyporheic zone within the main channel. Soils were collected from 3 depth in each area, and water content, pH, and DOC were measured. Various microbial properties including extracellular enzyme activities ($\beta$-glucosidase, N-acetylglucosaminidase, phosphatase and arylsulfatase), and microbial community structure using T-RFLP were also determined. The results exhibited a positive correlation between water content and DOC, and between extracellular enzyme activities and DOC. Distinctive patterns were observed in soils adjacent to water and hyporheic zone compared with other soils. Overall results of study provided basic information about microbial properties of hyporheic zone, which appeared to be discernable from other locations in the stream corridor.

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The Characteristics of a Career Counseling Network on Gifted Students of Science and general students (과학 영재와 일반 학생의 진로 상담 네트워크 특성)

  • Chung, Duk-Ho;Park, Seon-Ok;Yoo, Hyo-Hyun
    • Journal of Gifted/Talented Education
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    • v.25 no.1
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    • pp.21-36
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    • 2015
  • The purpose of this study is to examine social influence of the counselors on the network for a career counseling on gifted students of science and general students. This study collected data from 151 gifted students of science and 212 general students. The collected data was analyzed by the social network analysis. The results are as follows: First, we found that mother had the highest centrality indicators and teacher had the lowest centrality indicators on the career counseling network in both groups. And the max-flow indicators from mothers to teachers were the lowest on the career counseling network, on other hand; general students had lower centrality indicators than gifted students of science. Second, father was the most obvious counselor to cover for mother, on the hand, teacher was the worst counselor to cover for mother on the career counseling network. The gifted students group of science had less difficulty to cover for mother than the general students group. While teacher had the highest limits to information exchange on the career counseling network in both groups, mother had the lowest limits. As the result, we can conclude that mother played a key role on the career counseling network in gifted students of science and general students, while teachers was excluded from the career counseling network of students. Therefore, it is necessary to connect systematically parents with teachers for leading effectively students to their career; also government needs to build a career counseling system for this.

Morphometric Characteristics of Alluvial Fans in South Korea and Comparisons with those of Japan, Taiwan and the Philippines (한반도 남부 선상지의 계량적 지형 특성과 일본, 타이완, 필리핀 선상지와의 비교 연구)

  • Yoon, Soon-Ock;Saito, Kyoji;Hwang, Sang-Ill;Oguchi, Takashi;Tanaka, Yukiya
    • Journal of the Korean Geographical Society
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    • v.45 no.4
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    • pp.431-443
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    • 2010
  • The morphometric characteristics of 13 alluvial fans in the southern parts of the Korean Peninsula are studied and relationships between their distributions and causes are discussed by comparing them with 690 alluvial fans in Japan, Taiwan and the Philippines. The relationships between the surface gradient of alluvial fans and source basin area, the surface gradient and the relief ratio of the source basin, and the source basin area and the relief ratio were investigated. The alluvial fans in South Korea have typical characteristics of the Asian fans, although their frequency and density are relatively low, and the size and the relief ratio of their source basins are relatively small and steep, respectively. Moreover 36 major Korean river basins without alluvial fans tend to have lower altitude and relief ratios. Contrary to the argument by Blair and McPherson, the natural depositional gaps on the gradient of alluvial fans were not found. The Gyeongju alluvial fan is probably a fluvial fan with gentle gradient, whereas the other Korean fans seem to be debris-flow related on the base of their gradients.

Application of Lean Theory to BIM-Based Coordination - A Case Study on Process Re-Engineering of MEP Coordination - (린 기법의 BIM 기반 설계조율 프로세스 접목 - 설비전기 설계조율 프로세스 재설계 사례연구 -)

  • Jang, Se-Jun
    • Journal of the Korea Institute of Building Construction
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    • v.18 no.1
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    • pp.67-79
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    • 2018
  • This paper provides theoretical deformation of lean concept and its application for usage of building information modeling (BIM) process. Recently, much research is focused on application of lean concept for more efficient usage of BIM. The lean theory and its basic function and feature is based on manufacturing industry. The manufacturing process can be improved by process re-engineering steps of lean concept which consist of the steps of value, value stream, flow, pull, perfection. However manufacturing process and construction process has different characteristics. Due to the differences, five steps of the traditional lean's process re-engineering can't be directly applied to the BIM based engineering process. In order to solve this problem, we conduct analysis on the characteristics of the manufacturing process and BIM based engineering. We propose modified and expanded concept of lean for process re-engineering and the modified theory was applied to the mechanical, electrical and plumbing (MEP) coordination process. Through the proposed 8 steps of methodology, 2D based process was changed to integrated and using BIM based MEP coordination process. In addition, the results showed the potentiality of cost reduction and process improvement. The results of this study can be a foundation for the theoretical combination of lean and a variety part of construction engineering process.

A New Design of the Interrogating Waves for Medical Ultrasonic Imaging Based on Wavelets and Subband Filter Banks: A Simulation Study (의료용 초음파 영상시스템을 위한 Wavelet 과 Subband Filter Bank 에 기반한 새로운 탐침 파형의 설계: A Simulation Study)

  • Yang Yoon Seok
    • Journal of Biomedical Engineering Research
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    • v.25 no.6
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    • pp.431-438
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    • 2004
  • Medical ultrasonic imaging is a useful imaging facility known to be most safe and easy. It enables physicians to observe the inside structures of the bodies, blood flow, and motions of internal organs. Some physical properties of biologic tissues can also be estimated from backscattered sounds. However, the ultrasonic pulses interrogating the living organisms leave their footprints in the returning signals during imaging. Some significant details are buried in the footprints and their overlaps from adjacent particles. These distortions also decrease the quality of the images. Many research efforts have been made to enhance the image quality and to recover the acoustic information in various ways. In this study, a new interrogation method based on the wavelet and subband filter bank is proposed. It adopts the subband wavelet filters satisfying the perfect-reconstruction (PR) conditions as the interrogating pulses to restore the details useful in tissue characterization and to enhance the image quality. The proposed method was applied to two types of simulations of ultrasonic imaging. The results showed its ability to restore the detailsin the simulated interrogation of biologic tissues, and verified the improved image quality in the simulated imaging of general ultrasonic phantom compared with the conventional method.

A Study on Conservation and Management of the Joseon Royal Tomb's System - Focused on Joseon Royal Tombs Under the Eastern District Management Office - (조선왕릉의 능제보존관리에 관한 연구 - 동부지구관리소 산하 조선왕릉을 중심으로 -)

  • Choi, Jong-Hee;Lee, Chang-Hwan;Hwang, Kyu-Man;Kim, Kyu-Yeon
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.36 no.3
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    • pp.75-87
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    • 2018
  • The purpose of this study is to investigate conservation and management methods of the Joseon Royal Tombs under the Eastern District Management Office. Through the literature survey, we understood the process of change of Joseon royal tombs, and through field surveys and interviews, we understood the status of the interior and the surrounding area. In this process, topography, land use and flow of human traffic, architecture and stone objects, water system, historical forests, and facilities were set as the main evaluation indicators. Urbanization has damaged the original terrains of Royal Tombs as national roads, buildings and facilities have constructed in the inner and outer area of Joseon Royal Tombs. Construction of underground passage, land purchase, relocation and demolition of the buildings are required for the conservation of the Royal Tombs area, and then it is necessary to recover the original terrain. In the case of land use and pathways, there are many disconnection of the original ritual circulation, they should be maintained to remind the sacred atmosphere of the royal tomb. And It is necessary to collect accurate information on the lost buildings and stoneworks through literature survey and excavation investigation, and that investigations should be lead to the exposure or restoration of the ruins. Historical forests require periodic and ongoing monitoring and management, and it is necessary to establish new entrance area and appropriate facilities following the long-Term conservation and management plan. These plans should be classified into short, medium and long-Term projects according to urgency and securing financial resources with a long perspective to implement continuous and systematic projects.

Implementation of a Static Analyzer for Detecting the PHP File Inclusion Vulnerabilities (PHP 파일 삽입 취약성 검사를 위한 정적 분석기의 구현)

  • Ahn, Joon-Seon;Lim, Seong-Chae
    • The KIPS Transactions:PartA
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    • v.18A no.5
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    • pp.193-204
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    • 2011
  • Since web applications are accessed by anonymous users via web, more security risks are imposed on those applications. In particular, because security vulnerabilities caused by insecure source codes cannot be properly handled by the system-level security system such as the intrusion detection system, it is necessary to eliminate such problems in advance. In this paper, to enhance the security of web applications, we develop a static analyzer for detecting the well-known security vulnerability of PHP file inclusion vulnerability. Using a semantic based static analysis, our vulnerability analyzer guarantees the soundness of the vulnerability detection and imposes no runtime overhead, differently from the other approaches such as the penetration test method and the application firewall method. For this end, our analyzer adopts abstract interpretation framework and uses an abstract analysis domain designed for the detection of the target vulnerability in PHP programs. Thus, our analyzer can efficiently analyze complicated data-flow relations in PHP programs caused by extensive usage of string data. The analysis results can be browsed using a JAVA GUI tool and the memory states and variable values at vulnerable program points can also be checked. To show the correctness and practicability of our analyzer, we analyzed the source codes of open PHP applications using the analyzer. Our experimental results show that our analyzer has practical performance in analysis capability and execution time.

Holocene Climate Optimum and environmental changes in the Paju and the Cheollipo areas of Korea (한반도 홀로세 온난기후 최적기 (Holocene Climate Optimum)와 지표환경 변화)

  • Nahm, Wook-Hyun;Lim, Jae-Soo
    • The Korean Journal of Quaternary Research
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    • v.25 no.1
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    • pp.15-30
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    • 2011
  • Three sediment cores from two different locations (UJ-03 and UJ-12 cores of valley sediment in Paju area, and CL-4 core of wetland sediment in Cheollipo area) along the western Korean Peninsula yield crucial information on the timing and spatial pattern of century-scale climate changes and subsequent surficial responses during the Holocene. In Paju area, the sediments included abundant coarse-grained sediment (coarse sands and pebbles) from 7100 to 5000 cal. yrBP, total organic carbon (TOC) values showed a marked increase from 5000 to 2200 cal. yrBP, several intermittent depositional layers were observed from 2200 cal. yrBP. In Cheollipo area, lake environment developed from 7360 to 5000 cal. yrBP, the deposition of organic materials increased from 5000 to 2600 cal. yrBP, peatland formed from 2600 cal. yrBP. The two patterns of surficial responses to the climate changes through the Holocene are different to each other. This might be due to the dissimilarity in geomorphic conditions. However, the approximate simultaneity of environmental changes in two areas shows that they both can be correlated to the major climate changes. Two areas which have undergone significant changes indicated that the hydrological factors including precipitation and strength of water flow were most responsible for the landscape and geomorphic evolutions. Although the upwards trend in relative sea-level also played a primary role for environmental changes in coastal area (Cheollipo area), detailed studies have still to be undertaken.

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Urbanization in Pusan City, Korea: Changes of Traffic Volume (교통량 변화로 본 부산의 도시화)

  • Kim, Won-Kyung;Beun, Jeong-Hee
    • Journal of the Korean association of regional geographers
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    • v.4 no.2
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    • pp.1-14
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    • 1998
  • This research concerns with the urbanization in Pusan City, the largest port city of Korea focus on the changes of traffic volume from 1970 to 1994. These results are as follow: (1) Urbanization of Pusan City has progressed with increasing the efficiencies of streets. At the first, it's ribbon developed along the main artery toward inland. Urbanization is the process of bear a resemblance to characteristics of CBD. It has both expansion and diffusion processed, simultaneously. Urbanization has progressed centered certain nuclei and developed with more varieties are ally and temporally. (2) Traffic volumes according to times which go and return to piers affected to the traffic pattern of the some parts within the city, it is one of characteristics in port city. Variation of traffic volumes according to times much greater at the nearer streets the piers and connected street with it than the rest of the areas within the city. Rivers and mountains affecting to the traffic pattern and play roles of diffusion barriers for urbanization. (3) In the mid-1980, regions which locate along the main arteries had reached to as same level of urbanization as central part of the city. And higher ranked central places within Pusan City developed toward pattern of CBD in the past. It suggests that these central places revoluted to the recreation of CBD function in the past. (4) Urbanization has developed as same as cell differentiation in process, and it encouraged the more greater variation among the regions and become clear the hierarchy of central places within the city.

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