• Title/Summary/Keyword: Monthly calculation method

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Stochastic Modelling of Monthly flows for Somjin river (섬진강 월유출량의 추계학적 모형)

  • 이종남;이홍근
    • Water for future
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    • v.17 no.4
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    • pp.281-291
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    • 1984
  • In our Koreans river basins there are many of monthly rainfall data, but unfortrnately streamflow data needed are rare. Analysing monthly rainfall data of Somjin river basin, the stochastic theory model for calculation of monthly streamflow series of that region is determined. The model is composed of Box & Jenkins stansfer function plus ARIMA residual models. This linear stochastic differenced time series equation models can adapt themselves to the structure and variety of rainfall, streamflow data on the assumption of the stationary covarience. The fiexibility of Box-Jenkins method consists mainly in the iterative technique of building an AIRMA model from observations and by the use of autocorrelation functions. The best models for Somjin river basin belong to the general calss: $Y_t=($\omega$o-$\omega$_1B) C_iX_t+$\varepsilon$t$ $Y_t$ monthly streamflow, $X_t$ : monthly rainfall, $C_i$ :monthly run-off, $$\omega$o-$\omega$_1$ : transfer parameter, $$\varepsilon$_t$ : residual The streamflow series resulted from the proposed model is satisfactory comparing with the exsting streamflow data of Somjin gauging station site.

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Volume Calculation for Filling Up of Rubbish Using Stereo Camera and Uniform Mesh (스테레오 카메라와 균일 매시를 이용한 매립지의 환경감시를 위한 체적 계산 알고리즘)

  • Lee, Young-Dae;Cho, Sung-Youn;Kim, Kyung;Lee, Dong-Gyu
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.3
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    • pp.15-22
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    • 2012
  • For the construction of safe and clear urban environment, it is necessary that we identify the rubbish waste volume and we know the accuracy volume. In this paper, we developed the algorithm which computes the waste volume using the stereo camera for enhancing the environment of waste repository. Using the stereo vision camera, we first computed the distortion parameters of stereo camera and then we obtained the points cloud of the object surface by measuring the target object. Regarding the points cloud as the input of the volume calculation algorithm, we obtained the waste volume of the target object. For this purpose, we suggested two volume calculation algorithm based on the uniform meshing method. The difference between the measured volume such as today's one and yesterday's one gives the reposit of waste volume. Using this approach, we can get the change of the waste volume repository by reading the volume reports weekly, monthly and yearly, so we can get quantitative statistics report of waste volume.

Monthly Heating Energy Needs Analysis According to ISO 13790 and ISO 52016 (ISO 13790과 ISO 52016에 의한 월별 난방에너지 소요량 분석)

  • Zo, Chung-Hoon;Yun, Geun-Young
    • Journal of the Korean Solar Energy Society
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    • v.39 no.5
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    • pp.11-28
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    • 2019
  • Governments are increasing energy efficiency in buildings through various policies to reduce building energy consumption. In 2002, the European Union adopted a building energy performance guideline to set minimum efficiency standards for residential and commercial buildings. Starting in 2020, all EU member states should ensure that all buildings are Near-Zero Energy Buildings (NZEB). In Korea, the government issued a zero-energy certification system. Since 2020, public buildings are required to cover energy consumption with the energy produced in buildings. As the demand for building energy simulation has increased to increase the energy efficiency of these buildings, the International Standard Organization (ISO) has created a standard for calculating building energy requirements called ISO 13790. This standard was revised to ISO 52016 in 2017. In this research, ISO 13790, which calculates the energy needs of existing buildings, and ISO 52016, which replaces them, are compared and analyzed, and applied to the calculation of heating energy needs of buildings. For models without thermal zoning(Case A), the difference in annual heating energy needs calculated from each criterion is $1.08kWh/m^2$, which is about 2% higher in ISO 52016. In the case of the thermal zoning model(Case B), the difference in annual heating energy needs calculated by each standard was $0.97kWh/m^2$, which was about 2% higher than ISO 52016. The heating energy needs model without thermal zoning has a higher energy needs than the heating energy needs model with thermal zoning. It is about 16% energy at $8.58kWh/m^2$ for ISO 13790 and $8.69kWh/m^2$ for ISO 52016.

A Study on Earned Value Management System (EVMS) For Project Using ERP System (ERP 시스템을 이용한 프로젝트 EVMS에 관한 연구)

  • Park, Je-Won;Lee, Chang-Ho
    • Journal of the Korea Safety Management & Science
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    • v.12 no.4
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    • pp.145-151
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    • 2010
  • It seems that a primary concern of the project-based company, which provides a large scale product or service over long term period, is to run a successful project through systematic project process control and control costs. One of the typical project control methods is Earned Value Management System(EVMS) which analyses the precess through performance measurement. Even though the EVMS is a highly efficient tool in the managerial aspect, it cannot easily determine the Planned Value(PV), Actual Cost(AC), or Earned Value(EV) due to the indistinct criteria and extensive data. The accurate calculation of AC in particular, is the basic of project management, but most companies record direct personnel expenses or direct expenses only. Since they calculate indirect expenses based on the estimated ratio, it limits the systematic project management that reflects changes in profit and loss of a company. This study introduces a EVMS for project management and its actual case based on EVMS and ERP system which some additional modules are installed for performance measurement. It is expected that this new method enables a company to save time and effort, and also to improve transparency by specifying expense items in detail and to switch quarterly settlement to monthly by reducing the time of calculation.

A Study on ERP System for EVMS in Project-based Industry (프로젝트형 산업의 EVMS을 위한 ERP 시스템에 관한 연구)

  • Park, Je-Won;Lee, Chang-Ho
    • Proceedings of the Safety Management and Science Conference
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    • 2010.11a
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    • pp.343-348
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    • 2010
  • Earned Value Management System(EVMS) is a highly efficient tool in the project management, but it cannot easily determine the Actual Cost due to the indistinct criteria and extensive data. This study introduces a EVMS for project management and its actual case based on EVMS and ERP system which some additional modules are installed for performance measurement. It is expected that this new method enables a company to improve transparency by specifying expense items in detail and to switch quarterly settlement to monthly by reducing the time of calculation.

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Calculation of Total Maximum Daily Load using Instreamflow Requirement (하천유지유량을 이용한 일최대 오염허용부하량 산정 방안)

  • Chung, Eun-Sung;Kim, Kyung-Tae;Kim, Sang-Ug;Lee, Kil Seong
    • Journal of Korean Society on Water Environment
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    • v.24 no.3
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    • pp.317-327
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    • 2008
  • This study developed the methodology to calculate the total daily maximum load (TMDL) using the instreamflow requirement because the previous TMDLs were too simple to easily achieve. Instreamflow requirement which was the average low flow ($Q_{275}$) in the previous planning cannot consider the seasonal variation of streamflow. Therefore, this study used the instreamflow requirement which is a maximum value among hydrologic drought flow ($Q_{355}$), and environmental flows for ecology and scenery. The environmental flows for ecology were calculated using Physical HABitat SIMulation system (PHABSIM) which can estimate the necessary flow for fish survival by life cycle. Using the proposed method, all monthly TMDLs of streams in the Anyangcheon were calculated for the application.

Analysis of Energy Performance and PMV Improvement by Application of Passive Factor for Office Building Renewal (오피스건물 리뉴얼시 패시브 요소적용에 따른 에너지성능 및 PMV 개선에 관한 연구)

  • Hong, Won-Pyo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.28 no.12
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    • pp.55-64
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    • 2014
  • This paper presents a case study to investigate the monthly calculation method of ISO 13790 applied for a office building. The energy performance analysis according to improvement of insulation and air permeability of windows in K office buildings is investigated by means of building energy efficiency rating tool ($ECO_2-OD$). The K building energy system is tested experimently by the measurement of PMV(predicted mean vote) for the control of indoor thermal environment and heat transmission coefficient of windows and interior walls respectively, before and after the example K office building is remodeled passively. Therefore, Internet based energy assessment program of energy efficiency rating of office building can be applied as a program for the annual energy requirement and for evaluation of energy savings from the experimental and simulation results.

Characterization of Infiltration Analyses Using Long-Term Monitoring Flow Data (장기 모니터링 자료를 활용한 침입수 산정 방법론별 특성 분석)

  • Lee, Jaehyun;Kim, Insop;Oh, Jeill;Park, Chulhwi
    • Journal of Korean Society on Water Environment
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    • v.25 no.3
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    • pp.411-418
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    • 2009
  • The analysis of characteristics of water use evaluation and nighttime domestic flow evaluation was performed by using result from flow monitoring and surveying water supply records and nighttime domestic flow for a year. The analysis of correlations showed that, for both sites, the infiltration ratio and wastewater flow have shown a good relationship with high correlation factor and that the calculation of wastewater flow was highly affected by monthly rainfall depth as well as number of rain days. From this result, it was concluded that the measurement of infiltration should be performed when the rainfall does not significantly affect the sewer flow. Also, it is notable that each value of calculated using method for infiltration evaluation are not comparable to each other, but independent methods. In selecting of evaluation method for infiltration, therefore, a great emphasis should be imposed to the character of area and the seasonal factor in order to select optimal one. It is desirable way for evaluating infiltration and reduction ratio using result from an optimal method.

An Analysis of Economic Value of the Old-age Preparation Service (노후준비서비스의 경제적 가치 분석)

  • Ahn, Kyung Ae;Rhee, Hae Chun
    • Health Policy and Management
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    • v.28 no.1
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    • pp.77-86
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    • 2018
  • Background: The purpose of this study is to emphasize the importance and necessity of the government's old-age preparation service by measuring the economic value of the old-age service and the policy direction and policy implications of the government's old-age preparation service project. Methods: Contingent Valuation Method (CVM) was used as an analytical method. CV methodology was used to calculate the Willingness to pay (WTP) for old-age preparation service and its value was estimated and the economic benefit of the project was estimated. Results: As a result of the analysis, the average monthly payment amount for the old service was calculated as 5,100 won, and the annual average payment amount was estimated to be 61,197.1 won. Conclusion: The present value of the benefit for 10 years with the discount rate of 5.5% is 484,651 won. Based on the value of peruser benefit, the total benefit value calculation result of the old-age preparation service considering the Willingness to pay for the next 10 years shows that the total benefit value of the old service, which occurs during the period from 2016 to 2025(10 years) was estimated at 415.1 billion won. As a result of calculating the benefit for each scenario, the present value of basic service is higher in all scenarios than the linked service.

Comparative analysis of the global solar horizontal irradiation in typical meteorological data (표준기상데이터의 일사량 데이터 비교 분석)

  • Yoo, Ho-Chun;Lee, Kwan-Ho;Kang, Hyun-Gu
    • Journal of the Korean Solar Energy Society
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    • v.29 no.6
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    • pp.102-109
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    • 2009
  • The research on meteorological data in Korea has been carried out but without much consistency and has been limited to some areas only. Of relatively more importance has been the area in the utilization of the solar energy, however, the measurement of the global solar horizontal irradiation has been quite limited. In the current study, the actually measured value of the global solar horizontal irradiation from the meteorological data and the theoretically calculated value of the global solar horizontal irradiation from the cloud amount will be analyzed comparatively. The method of analysis will employ the standard meteorological data drafted by the Korean Solar Energy Society, the standard meteorological data from the presently used simulation program and the corresponding results have been compared with the calculated value of the global solar horizontal irradiation from the cloud amount. The results of comparing the values obtained from MBE(Mean Bias Error), RMSE(Root Mean Squares for Error), t-Statistic methods and those from each of the standard meteorological data show that the actually measured value of the meteorological data which have been converted into standard meteorological data with the help of the ISO TRY method give the monthly average value of the global solar horizontal irradiation. These values compared with the monthly average value from the IWEC from the Department of Energy of the USA show that the value of the global solar horizontal irradiation in the USA is quite similar. In the case of the values obtained from calculation from the cloud amount, the weather data provided by TRNSYS, except only slight difference, which means that the actually measured values of the global solar horizontal irradiation are significant. This goes to show that in the case of Korea, the value of the global solar horizontal irradiation provided by the Korea Meteorological Administration is will be deemed correct.