• Title/Summary/Keyword: Delivery load

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Estimation of Delivery Ratio Based on BASINS/HSPF Model for Total Maximum Daily Load (BASINS/HSPF 모형을 이용한 수질오염총량관리 유달율 산정방법 연구)

  • Park, Ju-Hyun;Hwang, Hasun;Rhew, Doughee;Kwon, Oh-Sang
    • Journal of Korean Society on Water Environment
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    • v.28 no.6
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    • pp.833-842
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    • 2012
  • In this study Window interface to Hydrological Simulation Program-FORTRAN (HSPF) developed by the United States Environmental Protection Agency (EPA) was applied to the upstream of Namgang watershed to estimate its applicability for estimating Delivery Ratio (DR) of water pollutants for Total Maximum Daily Load (TMDL). BASINS/HSPF which is selected in this study, is found to be appropriate for simulation of daily flow and water quality in target basins. DR was estimated utilizing discharge loads of unobserved sub-basin and delivery load of unobserved locations obtained not by actual evaluation but by simulation through validation and verification. Annual average DR of BOD, TN and TP were 0.97 ~ 1.50, 2.23 ~ 3.21, and 0.81 ~ 1.09 respectively. Net DR of dependent basins excluding influence of upstream basin was 1.50 ~ 1.70, 0.55 ~ 0.69, and 0.24 ~ 0.31, all of which are lower than those of independent basins area. Utilizing the model selected by this research, DR and Net DR of unobserved basins will be estimated, which will help determine priorities in management of basin areas.

Short-Term Prediction Model of Postal Parcel Traffic based on Self-Similarity (자기 유사성 기반 소포우편 단기 물동량 예측모형 연구)

  • Kim, Eunhye;Jung, Hoon
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.43 no.4
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    • pp.76-83
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    • 2020
  • Postal logistics organizations are characterized as having high labor intensity and short response times. These characteristics, along with rapid change in mail volume, make load scheduling a fundamental concern. Load analysis of major postal infrastructures such as post offices, sorting centers, exchange centers, and delivery stations is required for optimal postal logistics operation. In particular, the performance of mail traffic forecasting is essential for optimizing the resource operation by accurate load analysis. This paper addresses a traffic forecast problem of postal parcel that arises at delivery stations of Korea Post. The main purpose of this paper is to describe a method for predicting short-term traffic of postal parcel based on self-similarity analysis and to introduce an application of the traffic prediction model to postal logistics system. The proposed scheme develops multiple regression models by the clusters resulted from feature engineering and individual models for delivery stations to reinforce prediction accuracy. The experiment with data supplied by main postal delivery stations shows the advantage in terms of prediction performance. Comparing with other technique, experimental results show that the proposed method improves the accuracy up to 45.8%.

Study on Representation of Pollutants Delivery Process using Watershed Model (수질오염총량관리를 위한 유역모형의 유달 과정 재현방안 연구)

  • Hwang, Ha Sun;Rhee, Han Pil;Lee, Sung Jun;Ahn, Ki Hong;Park, Ji Hyung;Kim, Yong Seok
    • Journal of Korean Society on Water Environment
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    • v.32 no.6
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    • pp.589-599
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    • 2016
  • Implemented since 2004, TPLC (Total Pollution Load Control) is the most powerful water-quality protection program. Recently, uncertainty of prediction using steady state model increased due to changing water environments, and necessity of a dynamic state model, especially the watershed model, gained importance. For application of watershed model on TPLC, it needs to be feasible to adjust the relationship (mass-balance) between discharged loads estimated by technical guidance, and arrived loads based on observed data at the watershed outlet. However, at HSPF, simulation is performed as a semi-distributed model (lumped model) in a sub-basin. Therefore, if the estimated discharged loads from individual pollution source is directly entered as the point source data into the RCHRES module (without delivery ratio), the pollutant load is not reduced properly until it reaches the outlet of the sub-basin. The hypothetic RCHRES generated using the HSPF BMP Reach Toolkit was applied to solve this problem (although this is not the original application of Reach Toolkit). It was observed that the impact of discharged load according to spatial distribution of pollution sources in a sub-basin, could be expressed by multi-segmentation of the hypothetical RCHRES. Thus, the discharged pollutant load could be adjusted easily by modification of the infiltration rate or characteristics of flow control devices.

A Load Based Weight Multicasting Technique Design for efficient Multimedia Contents Delivery (효율적인 멀티미디어 컨텐츠 전송을 위한 부하 가중치 멀티캐스팅 기법의 설계)

  • Lee, Seo-Jeong;Kim, Seon-Ho
    • The Journal of Society for e-Business Studies
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    • v.9 no.3
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    • pp.277-288
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    • 2004
  • The purpose of multimedia contents transmission is to resolve the large size and nonformal issues. Various multicasting technologies have been researched to support these issues. This paper suggests a technique to build multicast routing for safe and reliable transmission of multimedia contents. Network server nodes have their own weight with respect to communication loads. The weight is computed by a server's communication load with others. This suggests low delay routing with two or more edge server of content delivery network. We will show the weighted inter-server routing technique and analyze the network performance improvement caused by lower network traffic and delay.

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End-to-end Reliable Message Transmission Considering Load Balancing in Wireless Networks

  • Tran, Anh Tai;Kim, Myung Kyun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.9
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    • pp.3094-3109
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    • 2014
  • This paper proposes a load balanced reliable routing protocol called LBR (Load Balanced Reliable routing) in wireless networks. The LBR protocol transmits messages through a reliable path considering the balancing of the traffic load. Recently, the authors have proposed a multipath-based reliable routing protocol called MRFR, which is an appealing protocol for fault tolerant reliable data transmission. However, However, MRFR has no concern with the problem of load balancing, which results in increasing congestion and consuming high energy at some network nodes. As a result, the problem affects negatively the performance of the network. Taking account of load balancing as a route selection criteria can avoid routing through the congested nodes and allows to find better routes. In this paper, we extend MRFR by considering load balancing in the route discovery process of reliable communication. The simulation results showed that the proposed protocol outperforms AODV in terms of end-to-end delay, packet delivery radio, and average jitter. Compared to MRFR, the LBR protocol has the same packet delivery ratio, and obtains a better efficiency of load balancing.

Reliability Assessment Considering Load Characteristics in Distribution Systems (배전계통에서 부하특성을 고려한 신뢰도평가에 관한 연구)

  • Park, Hyeon-Seok;Rho, Dae-Seok
    • Proceedings of the KAIS Fall Conference
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    • 2008.05a
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    • pp.87-90
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    • 2008
  • This paper deals with the analytical approach for the reliability assessment in radially operated distribution systems. The approach can estimate the expected reliability performance of distribution systems by a direct assessment of the configuration of the systems using the reliability indexes such as NDP(Non-Delivery Power) and NDE(Non-Delivery Energy). The indexes can consider the number and configuration of the load, but can not consider the characteristics of the load which is the one of the most important factor in the investment cost for the distribution systems. Therefore, This paper presents the new indexes considering the expected interruption cost for the load section and shows the effectiveness by simulating at the model systems.

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Development of a Method for Estimating Non-Point Pollutant Delivery Load of Each Reference Flow with Combination of BASINS/HSPF (BASINS/HSPF와 연계한 유황별 비점유달부하량 산정방법 개발)

  • Lee, Yong-Woon;Song, Kwang-Duck;Lee, Jae-Choon;Yoon, Kwang-Sik;Rhew, Doug-Hee;Lee, Su-Woong;Lee, Shin-Hoo
    • Journal of Korean Society of Environmental Engineers
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    • v.32 no.2
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    • pp.175-184
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    • 2010
  • The purpose of this study is to develop a method for estimating the non-point pollutant delivery load of each reference flow(flows of dry, low, normal, abundant and flood seasons) with combination of BASINS/HSPF. The effectiveness of this method is evaluated by applying it to the watershed of Dongbok stream. The flow, BOD and T-P reliability indices(RI) of the BASINS/HSPF for the watershed of Dongbok stream are 1.59, 1.41, 1.28, respectively, and thus the similarity between measured and estimated values is high. The non-point pollutant load delivery ratios of BOD and T-P for the flows of dry, low and normal seasons, which are estimated by such constructed BASINS/HSPF, are 0.36 and 1.09, 0.82 and 2.19, 6.02 and 16.90, respectively, as compared with daily average of non-point loads for a year. These results show that the non-point pollutant delivery load should be estimated and applied for each reference flow, and in this case the method for estimating the non-point pollutant delivery load of each reference flow can be useful.

A Study on Estimation of the Delivery Ratio by Flow Duration in a Small-Scale Test Bed for Managing TMDL in Nakdong River (낙동강수계 수질오염총량관리를 위한 시범소유역 유황별 유달율 산정방법 연구)

  • Shon, Tae-Seok;Park, Jae-Bum;Shin, Hyun-Suk
    • Journal of Korean Society on Water Environment
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    • v.25 no.5
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    • pp.792-802
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    • 2009
  • The objective of this study is to construct the watershed management system with link of the non-point sources model and to estimate delivery ratio duration curves for various pollutants. For the total water pollution load management system, non-point source model should be performed with the study of the characteristic about non-point sources and loadings of non-point source and the allotment of pollutant in each area. In this study, daily flow rates and delivered pollutant loads of Nakdong river basin are simulated with modified TANK model and minimum variance unbiased estimator and SWAT model. Based on the simulation results, flow duration curves, load duration curves, and delivery ratio duration curves have been established. Then GIS analysis is performed to obtain several hydrological geomorphic characteristics such as watershed area, stream length, watershed slope and runoff curve number. As a result, the SWAT simulation results show good agreements in terms of discharge, BOD, TN, TP but for more exact simulation should be kept studying about variables and parameters which are needed for simulation. And as a result of the characteristic discharges, pollutants loading with the runoff and delivery ratios, non-point sources effects were higher than point sources effects in the small-scale test bed of Nakdong river basin.

A study on the distribution system using Flexible Reliable Intelligent Electrical eNergy Delivery System (FRIENDS(Flexible Reliable Intelligent Electrical eNergy Delivery System)를 이용한 배전계통의 효율적인 운용방안 개발)

  • Kim, Yong-Ha;Lee, Hyeong-No;Jo, Jae-Han;No, Dae-Seok;Lee, Beom;Choi, Sang-Gyu
    • Proceedings of the KIEE Conference
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    • 1998.07c
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    • pp.1059-1062
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    • 1998
  • This paper which can simulate FRIENDS(Flexible Reliable Intelligent Electrical eNergy Delivery System) model of distribution electrical system presents a new algorithm. In the operation of FRIENDS model, dispersed energy storage(DES) systems have an important role. We can use the active and reactive power of DES to control customer's voltage. In this, the former means load levelling operation and the later means voltage control operation of DES. We focus our research on load levelling operation of DES. We develope an algorithm to get an optimal capacity and operation schedule of DES and then apply it to the FRIENDS model. The results show the effectiveness of the proposed method.

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Receiver-driven Cooperation-based Concurrent Multipath Transfer over Heterogeneous Wireless Networks

  • Cao, Yuanlong;Liu, Qinghua;Zuo, Yi;Huang, Minghe
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.7
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    • pp.2354-2370
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    • 2015
  • The advantages of employing SCTP-based Concurrent Multipath Transfer (CMT) have been demonstrated to be very useful for data delivery over multi-homed wireless networks. However, there is still significant ongoing work addressing some remaining limitations and challenges. The most important concern when applying CMT to data delivery is related to handling packet reordering and buffer blocking. Another concern on this topic is that current sender-based CMT solutions seldom consider balancing the overhead and sharing the load between the sender and receiver. This paper proposes a novel Receiver-driven Cooperation-based Concurrent Multipath Transfer solution (CMT-Rev) with the following aims: (i) to balance overhead and share load between the sender and receiver, by moving some functions including congestion and flow control from the sender onto receiver; (ii) to mitigate the data reordering and buffer blocking problems, by using an adaptive receiver-cooperative path aggregation model, (iii) to adaptively transmit packets over multiple paths according to their receiver-inspired sending rate values, by employing a new receiver-aware data distribution scheduler. Simulation results show that CMT-Rev outperforms the existing CMT solutions in terms of data delivery performance.