• Title/Summary/Keyword: Estimation Methodology

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Origin and destination matrix estimation using Toll Collecting System and AADT data (관측 TCS data 및 AADT 교통량을 이용한 기종점 교통량 보정에 관한 연구)

  • 이승재;장현호;김종형;변상철;이헌주;최도혁
    • Journal of Korean Society of Transportation
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    • v.19 no.5
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    • pp.49-59
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    • 2001
  • In the transportation planning process, origin and destination(O-D) trip matrix is one of the most important elements. There have been developments and applications of the methodology to adjust old matrices using link traffic counts. Commonly, the accuracy of an adjusted O-D matrix depends very much on the reliability of the input data such as the numbers and locations of traffic counting points in the road network. In the real application of the methodology, decisions on the numbers and locations of traffic counting points are one of the difficult problems, because usually as networks become bigger, the numbers of traffic counting points are required more. Therefore, this paper investigates these issues as an experiment using a nationwide network in Korea. We have compared and contrasted the set of link flows assigned by the old and the adjusted O-D matrices with the set of observed link flows. It has been analyzed by increasing the number of the traffic counting points on the experimental road network. As a result of these analyses, we can see an optimal set of the number of counting links through statistical analysis, which are approximately ten percentages of the total link numbers. In addition, the results show that the discrepancies between the old and the adjusted matrices in terms of the trip length frequency distributions and the assigned and the counted link flows are minimized using the optimal set of the counted links.

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The Estimation of Ecological Flow Recommendations for Fish Habitat (하천의 어류 서식환경을 고려한 생태학적 추천유량 산정)

  • Sung, Young-Du;Park, Bong-Jin;Joo, Gea-Jae;Jung, Kwan-Sue
    • Journal of Korea Water Resources Association
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    • v.38 no.7 s.156
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    • pp.545-554
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    • 2005
  • The detailed interdisciplinary surveys were conducted on the pattern of habitat use of dominant fishes during the spawning and adult stage. The hydraulic parameters of the depth and velocity, discharge, substrate cover streams, and distribution of fish in the Yeonggang, WiCheon, HoeCheon, GeochangwiCheon, CheongdoCheon, DanjangCheon (the Nakdong River Basin) were measured. The Habitat Suitability Criteria was developed for the two fish species (Zacco Platypus and Zacco Temmincki) and life stages(spawning and adult), habitat conditions (depth, velocity and covet). The Physical Habitat Simulation of the Instream Flow Incremental Methodology was applied to calculate for optimal flow and the ecological flow recommendation was proposed by choosing the largest one in the optimal flow. The ecological flow recommendation was $5.0\;m^3/s{\sim}10.0\;m^3/s$ (e.g., $6.5\;m^3/s$ in the NaeseongCheon). Also, the ecological flow recommendations were compared with the existing ecological flow and flow duration analysis.

A Study on the Estimation of Click Through Rates from Internet Search Results and their Value in the Evaluation of the Attractiveness of a Business Idea (사업 아이디어 매력도 평가를 위한 인터넷 검색엔진 광고 클릭률 추정에 관한 연구)

  • Shim, Jae-Hu;Choi, Myeong-Gil
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.4
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    • pp.1468-1474
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    • 2010
  • The establishment of a successful business must be preceded by comprehensive entrepreneurial preparation and research, as well as the development of a truly attractive business idea. Research to-date has tended to be based solely on factors relating to entrepreneurial activity or business performance. Research into the development and evaluation of a business idea has been insufficient. The purpose of this research is to propose a methodology for evaluating the attractiveness of a business idea objectively. This research measures the attractiveness of a business idea by the click through rate (CTR) to a website generated by specific keyword entry into internet search engines. The attractiveness of a business idea can be presented by the formula: number of relevant keyword searches x CTR on search results. As the number of searches for individual keywords is published by the search engines and it is possible to estimate CTRs for specific search results, we can objectively evaluate the attractiveness of a business idea. By analyzing keyword search data and CTRs obtained from search engines over a one month period, 1124 keywords that relate to foreign language education have been identified. A regression formula has also been derived, predicting the click through rate for search results. This research and its findings can be used to raise the success rates of new businesses; proposing objective guidelines for business idea development and evaluation. It is particularly meaningful because it introduces a new methodology to the arena.

Evaluation Methodology of Greenhouse Gas On-Line Monitoring on Freeway (고속도로 구간의 온실가스 On-Line 모니터링 산정방법)

  • Lee, Soong-bong;Chang, Hyun-ho
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.16 no.2
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    • pp.92-104
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    • 2017
  • Previous management for speed in road traffic system was aimed only to the improvement of mobility and safety. However, consideration for the aspect of environment and energy consumption efficiency was valued less than the former ones. Nevertheless, economical damage scope caused by climate change has been increasing and it is estimated that environmental value will be increased because of the change of external circumstances. In addition, policy for reducing carbon emission in transportation system was assessed as insufficient in improving the condition of traffic road since it only focused on the transition of private vehicle into public transportation and development of eco-friendly car. Now it is the time to prepare for the adaptation strategy and precaution for the increased number of private vehicle in Korea. For this, paradigm shift in traffic operation which includes the policy not only about the mobility but also about caring environment would be needed. It is needed to be able to monitor the actual amount of greenhouse gas in real time to reduce the amount of emitted greenhouse gas in the aspect of traffic management. In this research, a methodology which can build on-line greenhouse gas emission monitoring system by using real time traffic data and predicting the circumstance in next 5 minutes was suggested.

A Study on the Financial Service Negotiations in the Korean-Chinese Free-Trade Agreement (FTA) with Respect to RMB Internationalization (위안화 국제화를 고려한 한·중 FTA 금융서비스 협상 전략에 관한 연구)

  • Kim, Sang-Su;Son, Sam-Ho
    • Journal of Distribution Science
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    • v.11 no.4
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    • pp.81-88
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    • 2013
  • Purpose - This paper analyzes the influence of the RMB internationalization on the KRW/dollar exchange rate using an autoregressive distributed lag model. Comparing the parameter estimators from the sample period before and after the global financial crisis, we found that the RMB/dollar exchange rate has increasingly become more influential on the KRW/dollar exchange rate. Moreover, for the past several years, the Chinese government has actively utilized the financial service FTA negotiation as a measure for the RMB internationalization. This paper simultaneously considers RMB internationalization and financial service negotiations in the Korean-Chinese FTA. The purpose of this paper is to explicitly suggest a direction for the financial service negotiations in the Korean-Chinese FTA considering the effects of RMB internationalization. Research design, data, and methodology - The research plan of this paper has two parts. First, for an empirical study, this paper uses the daily exchange rate of the U.S. dollar against the currencies of the ASEAN5, Taiwan,and Korea. By using an autoregressive distributed lag model, this paper studies the influence of the change in the RMB/dollar exchange rate on changes in the local currency/dollar exchange rate in seven economies neighboring China. Our sample periods are 06/2005 - 07/2008 and 06/2010 -02/2013. During these periods, China was under the multi-currency basket system. We exempted the period of 08/2008 - 05/2010 from the analysis because there was nearly no RMB/dollar exchange rate fluctuation during those months. Second, after analyzing the recent financial service liberalizations and deregulations in China, we recommend a direction for the financial service negotiations in the Korean-Chinese FTA. In the past several years,the main Chinese financial policy agenda has surrounded the RMB internationalization. Therefore, it is crucial to understand this in the search for strategies for the financial service negotiations in the Korean-Chinese FTA. This paper employs an existing literature survey and examines the FTA protocols in its research methodology. Results and Conclusions - After the global financial crisis, the Chinese government wanted to break away from the dollar influence and pursued independent RMB internationalization in order to continue the growth and stability of its economy. Hence, every neighboring economy of China has been strategically impacted by RMB internationalization. Nevertheless, there is little empirical study on the influence of RMB internationalization on the KRW/dollar exchange rate. This paper is one of the few studies to analyze this problem comprehensively. By using a relatively simple estimation model, we can confirm that the coefficient of the RMB/dollar exchange rate has become more significant, except in the case of Indonesia. Although Korea is not under the multi-currency basket system but under the weakly controlled floating exchange rate system, its coefficient appears as large as that of the ASEAN5. This is the basis of the currency cooperation that has grown from the expansion of trade between the two countries. These empirical results suggest that the Korean government should specifically consider the RMB internationalization in the Korean-Chinese FTA negotiations.

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Development of the Process of Coordinate Transformation of Local Datum Cadastral Map to the World Geodetic System - Using Adjusted Coordinate - (지적도면의 세계측지계 좌표변환 프로세스에 대한 연구 - 조정좌표의 활용을 통해서 -)

  • Yang, Chul Soo
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.32 no.spc4_2
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    • pp.401-412
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    • 2014
  • This study is purposed on showing an effective process for coordinate transformation of cadastral maps, based on the local datum, in the World Geodetic System (WGS) for Cadastral Reform Project (CRP). The process follows three steps: coordinate adjustment, datum transformation and distortion modeling. The first procedure is that point coordinates on local datum has to be adjusted by those GPS observed point-to-point distances, using trilateration. Secondly, the adjusted coordinates need to be transformed to WGS by applying the Affine model, while the verification of the methodology is implemented under numerical experiments. To conduct this procedure, 195 points in the same coordinate origins in Seoul and 61 points in several different origins in Incheon are used in the estimation. As a result, there are less than 2cm coordinate differences between transformed coordinates and measured ones at everywhere. Also, it is remarkable that the transformation does not depend on either of the particular common points or the sizes of computed region. Therefore, this suggested methodology is expected to easily provide identifications and corrections for points-deviations for improved quality of the cadastral map by distortion modeling through CRP.

A Study on Verification of Delivery Ratio Methodology for Basic Plan at TPLMs(Total Pollutant Load Management System) (수질오염총량관리계획 수립을 위한 유달율 적용방안 검증 연구)

  • Lee, Sung Jun;Rhee, Han Pil;Park, Ji Hyung;Kim, Yong Seok;Hwang, Ha Sun
    • Journal of Korean Society of Environmental Engineers
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    • v.39 no.12
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    • pp.714-722
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    • 2017
  • The TPLMs is a system to manage the total amount of pollutants discharged from the watershed in order to achieve the target water quality of the river. In this process, the pollutant load can be classified into generation, discharge and delivery load. When using equation 2, the discharge coefficient should be 1. In case of using equation 3, it is considered that the discharge coefficient defined in the Technical Guideline should be applied. The delivery load is calculated as the product of the discharge load and the delivery ratio, and the delivery ratio is defined as the rate at which the pollutant discharged from the watershed reaches a specific point in the stream. In this study, the delivery ratio estimation method proposed by Hwang (2016) was applied to the Yonggang watershed in the Nakdong river. And the input data of QUALKO2 model was generated by using the estimated delivery ratio (equation 3) and the validation study was conducted by comparing with DRave (equation 2). As a result of the study, it is possible to use both the equation 2 and the equation 3, but it is necessary to change the methodology according to the application of the discharge coefficient.

Towards 3D Modeling of Buildings using Mobile Augmented Reality and Aerial Photographs (모바일 증강 현실 및 항공사진을 이용한 건물의 3차원 모델링)

  • Kim, Se-Hwan;Ventura, Jonathan;Chang, Jae-Sik;Lee, Tae-Hee;Hollerer, Tobias
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.46 no.2
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    • pp.84-91
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    • 2009
  • This paper presents an online partial 3D modeling methodology that uses a mobile augmented reality system and aerial photographs, and a tracking methodology that compares the 3D model with a video image. Instead of relying on models which are created in advance, the system generates a 3D model for a real building on the fly by combining frontal and aerial views. A user's initial pose is estimated using an aerial photograph, which is retrieved from a database according to the user's GPS coordinates, and an inertial sensor which measures pitch. We detect edges of the rooftop based on Graph cut, and find edges and a corner of the bottom by minimizing the proposed cost function. To track the user's position and orientation in real-time, feature-based tracking is carried out based on salient points on the edges and the sides of a building the user is keeping in view. We implemented camera pose estimators using both a least squares estimator and an unscented Kalman filter (UKF). We evaluated the speed and accuracy of both approaches, and we demonstrated the usefulness of our computations as important building blocks for an Anywhere Augmentation scenario.

A Methodology for 3-D Optimally-Interpolated Satellite Sea Surface Temperature Field and Limitation (인공위성 해수면온도 3-D 최적 내삽 합성장 생산 방법과 한계점)

  • Park, Kyung-Ae;Kim, Young-Ho
    • Journal of the Korean earth science society
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    • v.30 no.2
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    • pp.223-233
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    • 2009
  • Three-dimensional (3-D) optimally-interpolated sea surface temperature (SST) field was produced by using AQUA/AMSR-E satellite data, and its limitations were described by comparing the temporal average of sea surface temperatures. The 3-D OI (Optimum Interpolation) SST showed a small error of less than $0.05^{\circ}C$ in the central North Pacific, but yielded large errors of greater than $0.4^{\circ}C$ at the coastal area where the satellite microwave data were not available. OI SST composite around pixels with no observation due to heavy rainfall or cloudy pixels had estimation errors of $0.1-0.15^{\circ}C$. Comparison with temporal means showed a tendency that overall OI SSTs were underestimated around heavy cloudy pixels and smoothed out by reducing the magnitude of SST fronts. In the low-latitude areas near the equator, OI SST field produced discontinuity, originated from the window size for the OI procedure. This was mainly caused by differences in the spatial scale of oceanic features. Infernal Rossby deformation radius, as a measure of spatial stale, showed dominant latitudinal variations with O(1) difference in the North Pacific. This study suggests that OI SST methodology should consider latitudinally-varying size of window and the characteristics of spatial scales of oceanic phenomena with substantial dependency on latitude and vertical structure of density.

Application of an Automated Time Domain Reflectometry to Solute Transport Study at Field Scale: Experimental Methodology and Calibration of TDR (시간영역 광전자파 분석기(Automatic TDR System)를 이용한 오염물질의 거동에 관한 연구: 실험방법 및 검정)

  • Kim, Dong-Ju
    • Economic and Environmental Geology
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    • v.29 no.6
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    • pp.699-712
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    • 1996
  • Field scale experiments using an automated 144-channel TDR system were conducted which monitored the movement of solute through unsaturated loamy soils. The experiments were carried out on two different field plots of 0.54 ha to study the vertical movement of solute plume created by applying a square pulse of $CaCl_2$ as a tracer. The residence concentration was monitored at 24 locations on a transect and 5 depths per location by horizontally-positioning 50 cm long triple wire TDR probes to study the heterogeneity of solute travel times and the governing transport concept at field scale. This paper describes details of experimental methodology and calibration aspects of the TDR system. Three different calibration methods for estimation of solute concentration from TDR-measured bulk soil electrical conductivity were used for each field site. Data analysis of mean breakthrough curves (BTCs) and parameters estimated using the convection-dispersion model (CDE) and the convective-lognormal transfer function model (CLT) reveals that the automated TDR system is a viable technique to study the field scale solute transport providing a normal distribution of resident concentration in a high resolution of time series, and that calibration method does not significantly affect both the shape of BTC and the parameters related to the peak travel time. Among the calibration methods, the simple linear model (SLM), a modified version of Rhoades' model, appears to be promising in the calibration of horizontally-positioned TDR probes at field condition.

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