• Title/Summary/Keyword: Flow-based

Search Result 11,888, Processing Time 0.042 seconds

A Study on Types and Characteristics of 'Cultural Landscapes' with Big Data Analysis: Focusing on the Case of Shinan-gun, Jeollanam-do (빅데이터 분석을 통한 '문화경관' 유형과 특성 연구: 전라남도 신안군 사례를 중심으로)

  • OH Jungshim
    • Korean Journal of Heritage: History & Science
    • /
    • v.56 no.1
    • /
    • pp.162-180
    • /
    • 2023
  • The World Heritage Committee decided to make "cultural landscapes" a world heritage category in the 16th Session of the UNESCO General Conference. The decision was made from a recognition of the importance of interactions between human beings and the natural environment or between cultural heritage and natural heritage. Many countries have created policies and institutions to protect their own cultural landscapes along with the changing times. Korea, however, has not obviously defined the concepts and categories of its cultural landscapes, but manages policies and institutions based on the concept of a scenic spot, which has some similar meanings. In addition, it even borrows the "list of landscape adjectives," one of the representative methods for managing landscapes, from foreign countries. With this background, this paper suggested how to define cultural landscapes according to the global development flow. It created a list of cultural landscape adjectives by gathering the adjectives that can properly express local cultural landscapes in Korea. In particular, it collected 4,556 articles from a local newspaper by focusing on the case of Shinan-gun, Jeollanam-do, and analyzed key words and adjectives included in them by using big data analysis. The results suggested by this paper, such as the "classification table of cultural landscape types," "list of cultural landscape adjectives" and "network map of nouns/adjectives" can be applied to research on other localities, and furthermore, used as basic data for finding and protecting the characteristics of local cultural landscapes in Korea.

Propagation Analysis of Dam Break Wave using Approximate Riemann solver (Riemann 해법을 이용한 댐 붕괴파의 전파 해석)

  • Kim, Byung Hyun;Han, Kun Yeon;Ahn, Ki Hong
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.29 no.5B
    • /
    • pp.429-439
    • /
    • 2009
  • When Catastrophic extreme flood occurs due to dam break, the response time for flood warning is much shorter than for natural floods. Numerical models can be powerful tools to predict behaviors in flood wave propagation and to provide the information about the flooded area, wave front arrival time and water depth and so on. But flood wave propagation due to dam break can be a process of difficult mathematical characterization since the flood wave includes discontinuous flow and dry bed propagation. Nevertheless, a lot of numerical models using finite volume method have been recently developed to simulate flood inundation due to dam break. As Finite volume methods are based on the integral form of the conservation equations, finite volume model can easily capture discontinuous flows and shock wave. In this study the numerical model using Riemann approximate solvers and finite volume method applied to the conservative form for two-dimensional shallow water equation was developed. The MUSCL scheme with surface gradient method for reconstruction of conservation variables in continuity and momentum equations is used in the predictor-corrector procedure and the scheme is second order accurate both in space and time. The developed finite volume model is applied to 2D partial dam break flows and dam break flows with triangular bump and validated by comparing numerical solution with laboratory measurements data and other researcher's data.

Efficient QoS Policy Implementation Using DSCP Redefinition: Towards Network Load Balancing (DSCP 재정의를 통한 효율적인 QoS 정책 구현: 네트워크 부하 분산을 위해)

  • Hanwoo Lee;Suhwan Kim;Gunwoo Park
    • The Journal of the Convergence on Culture Technology
    • /
    • v.9 no.3
    • /
    • pp.715-720
    • /
    • 2023
  • The military is driving innovative changes such as AI, cloud computing, and drone operation through the Fourth Industrial Revolution. It is expected that such changes will lead to a rapid increase in the demand for information exchange requirements, reaching all lower-ranking soldiers, as networking based on IoT occurs. The flow of such information must ensure efficient information distribution through various infrastructures such as ground networks, stationary satellites, and low-earth orbit small communication satellites, and the demand for information exchange that is distributed through them must be appropriately dispersed. In this study, we redefined the DSCP, which is closely related to QoS (Quality of Service) in information dissemination, into 11 categories and performed research to map each cluster group identified by cluster analysis to the defense "information exchange requirement list" on a one-to-one basis. The purpose of the research is to ensure efficient information dissemination within a multi-layer integrated network (ground network, stationary satellite network, low-earth orbit small communication satellite network) with limited bandwidth by re-establishing QoS policies that prioritize important information exchange requirements so that they are routed in priority. In this paper, we evaluated how well the information exchange requirement lists classified by cluster analysis were assigned to DSCP through M&S, and confirmed that reclassifying DSCP can lead to more efficient information distribution in a network environment with limited bandwidth.

A Study on the Effects of Teacher Librarians' Media and Information Literacy Classes: Focused on the High School Credit System (사서교사의 미디어 정보 리터러시 수업 효과에 관한 연구 - 고교학점제를 중심으로 -)

  • Bong-Suk Kang;Juhyeon Park
    • Journal of the Korean Society for Library and Information Science
    • /
    • v.57 no.2
    • /
    • pp.179-198
    • /
    • 2023
  • The purpose of this study is to verify the role of teacher librarians by examining the cases of media and information literacy(MIL) classes in the joint curriculum of high school credit system research school. The classes were two 34th classes joint curriculum established by two teacher librarians at the high school credit system research school. Individual students set their own inquiry problems integrated with their careers or subjects, and teacher librarians guide the process of solving them based on the process of using MIL. The participants were 22 high school students in Daegu who filled out the questionnaire before and after completing the course. The effect of the classes was analyzed through a questionnaire consisting of 42 questions for the 3 factors of access, evaluation, and creation, which are the components of MIL announced by UNESCO. As a result, all 3 factors and 25 of the sub-42 survey items showed a statistically significant difference before and after class, It was investigated that literacy of students improved through MIL education of teacher librarians. Through this study, it will be possible to expand the awareness of the effect of the educational role of teacher librarians in the flow of future curriculum.

A Study on Application Standard of At-grade Intersection Considering Both Delay and Accident (지체와 사고를 고려한 평면교차로 적용기준에 관한 연구)

  • Park, Je Jin;Jung, Hyung Mo;Ha, Tae Jun
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.28 no.3D
    • /
    • pp.295-306
    • /
    • 2008
  • The Intersection is inner traffic facilities and the space where the roads are intersected and connected. And also, the Intersection is the decision-making section for drivers to select the route according to the geometric structure and operation method. However decision-making section cause to raise car accidents rate because it imposes a heavy burden on drivers. In that reason, many countries such as Europe use the Roundabouts to reduce the numbers of decision making and collision. In Korea, the kinds of method are just introduced and it is using now but there are no exact standards. Hence, this study suggests the process to evaluate and determine the types of Intersection which are based on the traffic flow (congestion) and traffic safety (accidents). Firstly, this study presents the number of accident at each Intersection which is depended on the traffic volume. Secondly, this study calculates and analysis the accident at signalized Intersection, non-signalized Intersection and Roundabout by TSIS-NETSIM program. Thirdly, this study concludes the best suitable Intersection type through the materials which are mentioned before.

A Constitutive Model for Rotation of Principal Stress Axes during Direct Simple Shear Deformation (직접단순전단변형에 따른 주응력 방향의 회전을 고려한 구성모델)

  • Park, Sung-Sik;Lee, Jong-Cheon
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.28 no.1C
    • /
    • pp.53-62
    • /
    • 2008
  • A constitutive model, which can simulate the effect of principal stress rotation associated with direct simple shear test, is proposed in this study. The model is based on two mobilized planes. The plastic strains occur from the two mobilized planes, and depend on stress state, and they are added. The first plane is a plane of maximum shear stress, which rotates about the horizontal axis, and the second plane is a horizontal plane which is spatially fixed. The second plane is used to consider the effect of principal stress rotation on simple shear tests under different stress states. The soil skeleton behavior observed in drained simple shear tests is captured in the model. This constitutive model is incorporated into the dynamic coupled stress-flow finite difference program FLAC. The model is first calibrated with drained simple shear tests on loose Fraser River sand. The measured shear stress and volume change are partially induced by principal stress rotation and compared with model calculations. The model is verified by comparing predicted and measured settlements due to rigid footing resting on loose sands. Settlements predicted by the proposed model were very similar to measured settlements. Mohr-Coulomb model can not consider the effect of principal stress rotation and its prediction was only 20% of measured settlements.

Evaluation of Levee Reliability by Applying Monte Carlo Simulation (Monte Carlo 기법에 의한 하천제방의 안정성 평가)

  • Jeon, Min Woo;Kim, Ji Sung;Han, Kun Yeun
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.26 no.5B
    • /
    • pp.501-509
    • /
    • 2006
  • The safety of levee that depends on the river flood elevation has been regarded as very important keys to build up various flood prevention systems. However, deterministic methods for computation of water surface profile cannot reflect the effect of possible inaccuracies in the input parameters. The purpose of this study is to develop a methodology of uncertainty computation of design flood level based on steady flow analysis and Monte Carlo simulation. This study addresses the uncertainty of water surface elevation by Manning's coefficients, design discharges, river cross sections and boundary condition. Monte Carlo simulation with the variations of these parameters is performed to quantify the variations of water surface elevations in a river. The proposed model has been applied to the Kumho-river. The reliability analysis was performed within 38.5 km (95 sections) reach considered the variations of the above-mentioned parameters. Overtopping risks were evaluated by comparing the elevations of the flood condition with the those of the levees. The results show that there is a necessity which will raise the levee elevation between 1 cm and 56 cm at 7 sections. The model can be used for preparing flood risk maps, flood forecasting systems and establishing flood disaster mitigation plans as well as complement of conventional levee design.

Residual Pesticide Analysis Method of Edible Oil via Heat Distillation Methods (가열증류법에 의한 식용유지의 잔류농약 분석법 개발)

  • Mi-Hui Son;Jae-Kwan Kim;Young-Seon Cho;Na-Eun Han;Byeong-Tae Kim;Myoung-Ki Park;Yong-Bae Park
    • Journal of Food Hygiene and Safety
    • /
    • v.38 no.3
    • /
    • pp.89-98
    • /
    • 2023
  • Currently, no guidelines exist regarding the maximum residues of pesticides in edible oil which is a processed food commonly consumed in Korea. This lack of guidelines hinders the evaluation of the safety of edible oil in terms of pesticide contamination. In this study, an analysis method based on heat distillation and GC-MS/MS was established by optimizing the extraction and purification procedure for 68 pesticides. Important variables in the thermal distillation procedure included heating temperature and time, and we found the nitrogen flow rate as a mobile phase and the type of dissolving solvent were not considerably affected. The determination coefficient (R2) of the residual pesticide was 0.99 or higher, and the quantitative limit (LOQ) was 0.01-0.02 mg/L. The average recovery rate (n=5) was 66.1-120.0% and the relative standard deviation was lower than ±10% when 68 pesticides were spiked at concentrations of 0.01-0.02, 0.1, and 0.5 mg/L. In addition, the within-laboratory precision was less than ±11%, meeting the Korea Food and Drug Safety Evaluation Institute's Guidelines on Standard Procedures for Preparing Food Testing Methods (2016). Therefore, the test method developed in this study can be used as a test method for managing the safety of the residual pesticide concentration in edible oil.

Estimation of Pollutant EMCs and Loadings in Highway Runoff (국내 고속도로 강우 유출수의 EMCs 및 유출 부하량 산정)

  • Kim, Lee-Hyung;Ko, Seok-Oh;Lee, Byung-Sik;Kim, Sunggil
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.26 no.2B
    • /
    • pp.225-231
    • /
    • 2006
  • The nonpoint source control is based on TPLMS (Total Pollution Load Management System) program. Recently, the Ministry of Environment in Korea has programed TPLMS for 4 major large rivers to improve the water quality in rivers by controling the total pollutant loadings from the watershed area. Usually the urbanization is the main pollutant sources, particularly for nonpoint pollutants, because of high imperviousness and high pollutant mass emissions. The stormwater runoff from urban areas is containing various pollutants such as sediments, metals and toxic chemicals due to human and vehicle activities. Of the various landuses, the highways are highly polluted landuses because of high pollutant accumulation rate by vehicle activities during dry periods. Therefore, this research is achieved to provide pollutant EMCs (Event Mean Concentrations) and mass loadings washed-off from highways during rainfall periods. Five monitoring locations were equipped with an automatic rainfall gage and an flow meter. The results show that the EMC ranges for 95% confidence intervals in highway land use are 45.52-125.76 mg/L for TSS, 52.04-95.48 mg/L for COD, 1.77-4.48 mg/L for TN, 0.29-0.54 mg/L for TP. The ranges of washed- off mass loading are $712.7-2,418.4mg/m^2$ for TSS and $684.1-1,779.6mg/m^2$ for COD.

The Impact of US Monetary Policy upon Korea's Financial Markets and Capital Flows: Based on TVP-VAR Analysis (미국 통화정책이 국내 금융시장 및 자금유출입에 미치는 영향: TVP-VAR 모형 분석)

  • Suh, Hyunduk;Kang, Tae Soo
    • Economic Analysis
    • /
    • v.25 no.2
    • /
    • pp.132-176
    • /
    • 2019
  • We use a time-varying parameter vector auto regression (TVP-VAR) model to understand the impact of U.S. monetary policy normalization on Korean financial markets and capital accounts. The U.S. monetary policy is represented by the federal funds rate, term premium and credit spread. During the U.S. monetary contraction period of 2004 to 2006, changes in the federal funds rate presented negative pressure on Korean financial markets. The changes in federal funds rate also led to a simultaneous contraction in inward and outward capital flows. However, the effects of a federal funds rate shock has been reduced since 2015. On the other hand, the effects of U.S. term premiums is getting stronger after the period of quantitative easing (QE). The influence of the U.S. credit spread also significantly increased after the global financial crisis. Simulation results show that a rise in the U.S. credit spread, which can be triggered by a contractionary monetary policy, can pose a larger adverse impact on the Korean economy than a rise in the federal funds rate itself. As for capital flows, a U.S. monetary policy contraction causes an outflow of foreign investment, but the repatriation of overseas investment by Korean residents can offset this outflow.