• Title/Summary/Keyword: 수치적 접근

Search Result 636, Processing Time 0.027 seconds

A Study on the Land Suitability Analysis Based on Site Selection Variables using Macro Language (매크로 언어를 이용한 입지인자 변수조정에 따른 토지적합성 분석에 관한 연구)

  • Yi, Gi-Chul
    • Journal of the Korean Association of Geographic Information Studies
    • /
    • v.6 no.1
    • /
    • pp.59-77
    • /
    • 2003
  • This study is to validate the use of macro language for the land suitability analysis aiming to help to resolve land use conflicts. The silver-town suitability analysis is conducted on the Geejang Gun, Busan Metropolitan city. Such digital maps as terrain, road, facility, and water body were created for various cartographic models. A cartographic model identified the best suitable areas for silver-town development based on the such site selection variables as a distance to facility and road, slope and aspect of terrain, land use etc. Then, the other cartographic model identified the most favorable site among the candidate sites based on the comparison of the aspect of proximity, usage and environmental quality. Macro language was used for these modeling process and was used for the manipulation of all these spatial variables used in the models to resolve land use conflicts relating to the decision making process of the final site selection. This study will improve the effectiveness and rationality of the traditional site suitability analysis.

  • PDF

Track Stability Assessment for Deep Excavations in Adjacent to Urban Railways (도시철도 인접지반 깊은 굴착 시 궤도 안정성 평가)

  • Jeon, Sang-Soo;Lee, Sang-Seung
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.19 no.6
    • /
    • pp.614-627
    • /
    • 2018
  • Urban railway lines have been constructed adjacent to residential buildings and urban areas. The expansion of transportation networks and reconstruction of residential buildings in highly populated urban areas require deep excavations in areas adjacent to urban railways. Mobilized soil stresses and changes in the groundwater level induced by deep excavations results in track irregularities in urban railways. In this study, a three-dimensional finite difference model using the commercial program FLAC3D was adopted to estimate the horizontal displacements of earth retaining structures, settlements of backfill, the stability of track irregularity and underground box structure based on the criteria of each railway organization and its relationships. In deep excavations, a change in groundwater level induces relatively very small differences for track gauge irregularities, whereas relatively large differences for longitudinal irregularities of 72.5%, twist irregularities of 83.3%, cross level irregularities of 61.9%, and alignments of 43.3% were found to be the maximum differences when the horizontal displacement of earth retaining wall and settlement of backfill were 65.1% and 21.4%, respectively, because the groundwater level (GWL) on the ground surface-mobilized tensile strength of the underground box structure exceeds the allowable value. Therefore, three-dimensional numerical analysis was performed in this study. Overall, real-time monitoring should be carried out to prevent railway accidents in advance when a deep excavation adjacent to urban railway structures is constructed.

A Development of Remote Bird Observation System Using FMCW RADAR (FMCW 레이더를 이용한 원격 조류(鳥類) 관측 시스템 개발)

  • Lee, Hee-Yong;Hwang, Hun-Gyu;Choi, Myung-Gil
    • Journal of the Korean Society for Marine Environment & Energy
    • /
    • v.17 no.3
    • /
    • pp.247-256
    • /
    • 2014
  • Recently, camera and RADAR are used for more effective and accurate observation of the bird migration. In recent years, many researches on the bird migration using RADAR are undertaking and in active, thus causes the advent of "RADAR ornithology" as a new academic field. Due to the lack of accessibility, economic feasibility and mobility of weather RADAR, airport searching RADAR and tracking RADAR, Nowadays, a marine RADAR is widely used for a bird observation. In this paper, we deals with a study on development of a remote bird observation system using marine FMCW RADAR, which monitors, records and analyzes bird movement by RADAR image processing and target recognition technology. Also, we conduct first test and second test for availability of the developed system, and verify the system to apply in bird observation domain. Consequently, we figured problems out, and correct the problems to improve the system. The developed system can apply in other domains such as environment evaluation. In the future, the system needs to improve accuracy of statistics and to track migration route of bird.

Childhood Arsenic Exposure and Health Risk Assessment from Rice Cultivated Near the Mining Areas in Korea

  • Paik, Min-Kyoung;Kim, Won-Il;Im, Geon-Jae;Hong, Moo-Ki
    • Journal of Food Hygiene and Safety
    • /
    • v.25 no.2
    • /
    • pp.148-152
    • /
    • 2010
  • Domestic studies for identification of causality between children exposure to toxic chemicals, such as arsenic (As) and resulted hazardous effects were not implemented. This study was conducted to probabilistically estimate dietary As intake and health risk assessment for young children and all age-specific populations from the consumption of As-contaminated rice of Korea. Arsenic intakes for young children (1 to 6 years old) from As-contaminated rice were higher than other age-specific groups, based on a dose-per-body weight basis. Based on the current EPA cancer slope factor for As, estimated cancer risks (to the skin cancer) associated with dietary intake of As-contaminated rice for 1 to 2 years old group and 3 to years old group are 1.76 per 10,000 and 3.16 per 10,000, respectively, at the 50th percentile. Based on possible reference levels (0.005 mg/kg/day) for children, mean and $95^{th}$ percentile value of HQ from rice for young children are very below 1.0, which is a regulatory limit of non-carcinogenic risks for human.

A Numerical Model for Predicting the Radial Power Profile in CANDU-PHWR Fuel Pellet (CANDU-PHWR 핵연료 소결체의 반경방향 출력분포 수치모형)

  • Woan Hwang;Suk, Ho-Chun;Jae, Won-Mok
    • Nuclear Engineering and Technology
    • /
    • v.23 no.4
    • /
    • pp.444-455
    • /
    • 1991
  • An accurate and fast running NEDAR model for calculating radial power profile throughout fuel life in both solid and annular pellets for existing and advanced CANDU-PHWR-fuel was developed in this work. This model contains resultant flux depression equations and neutron depression data tables which have been developed for CANDU-PHWR fuel of pellet with the diameter 8.0 to 19.5 mm and enrichment 0.71-6.0 wt % U-235, over a bumup range of 0 to 840 MWh /kgU (35000 MWD/T). In order to obtain the neutron flux distribution in the fuel pellet, the CE-HAMMER physics code was run for a neutron flux spectrum appropriate to a CANDU-PHWR to give predictions of radial power profile for several ranges of fuel design parameters. The results, which were calculated by the CE-HAMMER physics code, were fitted to an equation which is solved in terms of Bessel and exponential functions in order to obtain the parameters, $textsc{k}$, $\beta$ and λ in the resultant equation. The present NEDAR model produce a radial profile which, when normalized to unity at the pellet surface, is slightly higher than the profile of the original ELESIM data table. The predictions of the fission gas release by KAFEPA-NEDAR are in slightly better agreement with the experiments than those of ELESIM. The NEDAR model described in this study has been shown to provide an effective, reliable, and accurate method for determining radial power profiles in CANDU-PHWR fuel rods without incurring a significant increase in computing time.

  • PDF

Seepage Characteristics of Embedded Rock Layer Under the Earth Fill (성토제 하부에 매설된 사석층의 침투특성)

  • Lee Haeng-Woo;Chang Pyoung-Wuck
    • Journal of the Korean Geotechnical Society
    • /
    • v.21 no.8
    • /
    • pp.63-72
    • /
    • 2005
  • Rocks are dumped to soft marine ground in order to improve trafficability and construction conditions in the tideland reclamation construction sites. Though this rock layer under earth fill has caused in a serious seepage problems after construction, seepage behaviors of this embankment structure is not correctly investigated. Water flow through rock layers is, in general, known as Non-Darcy's flow. However, the embedded rock layer under earth fill is not known whether its flow is governed by Darcy's or Non-Darcy's law. Therefore, a numerical analysis, laboratory model test and filed investigations were performed for analyzing the those seepage characteristics in this research. Results show that there is significance of $95\%$ of confidence between observed heads and seepage rates, and the calculated ones by SAMTLE which is developed under the assumption that the water flows through the two-layer system obey the Darcy's flow. And after operating the hydraulic gradient(i) of $0.10\~0.55$ upon laboratory model, these seepage characteristics of the embedded rock layer show that Reynolds Numbers are less than 10 and the relationship between these velocities of rock layer(v) and hydraulic gradients(i) is linearly proportional with more than 0.79 of the coefficient of correlation $(R^2)$. And the Reynolds Number of the velocity calculated by the relation of v=ki in the embedded rock layer of OO sea dike is $1\~6$. It shows also laminar flow. Based on these results, it is concluded that the seepage characteristics of embedded rock layer under earth fill can be laminar and Darcy's flow.

Reference Station of Aerial Photogrammetry with GPS/INS by VRS (GPS/INS 항공사진측량의 지상기준국 측량의 VRS(가상기준점)적용에 관한 연구)

  • Song, Tae-Min;Kwon, Jay-Hyoun
    • Korean Journal of Remote Sensing
    • /
    • v.24 no.4
    • /
    • pp.381-388
    • /
    • 2008
  • In the common practice of air-photographing measurement aerial-photogrammetric, the location of camera at the time of photographing is identified by performing aerotriangulation. However, installing ground-base station to enable aerotriangulation takes majority portion of a map making cost. Aerial-photogrammetric has shown a great improvement helped by steady upgrading in equipment and development in quantitative study. Aerotriangulation can be replaced by Direct Georeferencing, which uses GPS/INS to identify a camera location and to produce detailed information. An innovative technique replacing aerotriangulation, it has a disadvantage that base station has to be available in the area of photographing. The study intends to suggest a method applying VRS in GPS/INS aerotriangulation. Despite the fact that Direct Georeferencing is the innovated technique which substitutes existing aerotriangulation, it still need to install the ground-base station in GPS/INS aerotriangulation. GPS/INS data was analyzed with 4 different cases in order to accomplish the purpose of this study. In addition, in the thesis, it was approved that VRS can be utilized to make small-scale map as accurate as base station. This study is expected to improve the efficiency of work by showing that VRS can be used not only in base station but also enabling base station in the ground-access challenging area.

Numerical Analysis and Exploring of Ground Condition during Groundwater Drawdown Environment in Open-cut Type Excavation (개착식 굴착공사시 지하수위 저하로 인한 지반상태 탐사 및 해석기법 연구)

  • Han, Yushik
    • Journal of the Korean Geotechnical Society
    • /
    • v.34 no.11
    • /
    • pp.93-105
    • /
    • 2018
  • Precise investigation and interpretation of the ground subsidence risk factors needed to predict and evaluate the settlement problems of the surrounding ground due to the ground excavation. There are various geophysical exploration methods to investigate the ground subsidence risk factors. However, there are factors that influence the characteristics of the underground medium in these geophysical methods, and the actual soil contains complex factors affecting geophysical exploration. Therefore, it is necessary to analyze the effects on the geophysical methods based on the understanding of the geotechnical properties of soil. In this study, a test bed was constructed to consider various complicated factors in the complex ground and the ground behavior was analyzed by numerical analysis. In addition, we analyzed the limitations on investigating the ground subsidence risk factors through ground penetration radar (GPR) survey. As a result, ground subsidence of Open-cut Type Excavation is caused by various factors. Especially, in the case of soft ground condition, it was found that it was greatly influenced by the flow change of groundwater level. At the center frequency of GPR of 250 MHz, the attenuation of the electromagnetic wave is severely attenuated in the clay with high electrical conductivity, making it difficult to penetrate deeply into the ground (4 m below the surface). As the electromagnetic waves pass through the groundwater level below the groundwater, the attenuation of the electromagnetic waves becomes severe.

Stability Analysis of Unsaturated Weathered Soil Slopes Considering Rainfall Duration (지속강우특성에 따른 불포화 풍화토사면의 안정성분석)

  • Jeong, Sang-Seom;Choi, Jae-Young;Lee, Jae-Hwan
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.29 no.1C
    • /
    • pp.1-9
    • /
    • 2009
  • In this study, the influence of wetting band depth by continuous rainfall and the magnitude of wetting front suction on the stability of slopes in weathered soils were investigated by using finite element programs SEEP/W and SLOPE/W. Three different intensities of rainfall (10mm/hr, 30mm/hr, 50mm/hr) were chosen, and the total duration of rainfall was 96 hours. Three infinite slopes with the inclination of 1:1.5 and 1:1.8, 1:2.0 were considered and the typical properties and the shear strength parameters of the weathered soil were applied. It is shown that rainfall duration plays an important role in slope stability. Based on the analytical results, it is found that as the rainfall duration increases, the wetting band depth also increases. Also, the increasing rate of the wetting band depth was decreased as the soil density was increased. These results come from the decrease of the coefficient of permeability and the increase of the soil suction. Finally, it is also shown that the safety factors of slopes by unsaturated analysis are mostly larger than those by saturated analysis. Therefore, commonly used saturated analysis may substantially underestimate the degree of safety factor in realistic situations.

Complementary and Alternative Medical Therapies in Children and Adolescent with Chronic Disease : Utilizations and Patterns (만성 질환을 가진 소아, 청소년에게 시행되는 보완대체요법의 실태 연구)

  • Kim, Young Bin;Song, Jun Ho;Jang, Myoung Wan;Yoo, Hwang Jae;Kim, Cheol Hong;Lee, Hyun Hee
    • Clinical and Experimental Pediatrics
    • /
    • v.48 no.9
    • /
    • pp.929-934
    • /
    • 2005
  • Purpose : This study describes how often complementary and alternative medical(CAM) therapies, what patterns of CAM therapies utilization, what types of CAM therapies and why CAM therapies are used in children and adolescent with chronic disease. Methods : We interviewed and filled out questionnaires with parents of patients suffering from asthma, atopic dermatitis, congenital myopathy, epilepsy and so on from Mar 2004 to Aug 2004. Results : Two hundred fifty two parents answered questionnaires; 160 cases(63.5 percent) had used CAM therapies. Utilization of CAM therapies according to each chronic disease was as follows : congenital myopathy(100 percent), atopic dermatitis(91.1 percent), asthma(72.5 percent), chronic diarrhea (50.0 percent), epilepsy(17.1 percent) etc. Types of CAM therapy were as follows : dietary supplement (31.1 percent), herb medicine(23.4 percent), massage(14.2 percent), acupuncture(4.6 percent) etc. Sixty four(40.0 percent) case underwent more than two types of CAM therapies simultaneously. One hundred thirty three(83.1 percent) case were asked through non-medical prescription. Ninety nine(61.9 percent) case were recognized positive effect of CAM therapies. Parents' and childrens' ages were influential factors in CAM therapies utilization : the older the parents and the younger the children, the higher the utilization. Conclusion : Although patients receive treatment with western medicine, many of them not only undergo CAM therapies, especially more than two types, but also recognize the positive effects of CAM therapies. As a result, we suggest that it is easy to use of CAM therapies, and the positive effects of CAM therapies are prominent, domestically. Therefore, medical approach and study about the effectiveness and side effects of CAM therapies is necessary to avoid the imprudent use of such therapies.