• Title/Summary/Keyword: Load Management

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Development of a Groundwater Quality Sampling Method for Livestock Excreta Survey (가축분뇨실태조사를 위한 지하수 오염현황조사 지점 선정 방법 개발)

  • Kim, Deok-Woo;Ryu, Hong-Duck;Baek, Unil;Kim, Sunjung;Shin, Dong Seok;Lee, Jae Gwan;Chung, Eu Gene
    • Journal of Environmental Science International
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    • v.28 no.1
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    • pp.37-54
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    • 2019
  • The groundwater quality through livestock excreta survey based on "Act of the management and use of livestock excreta" was investigated by selecting sampling sites within 1 km of the farmland without considering hydrogeological units. However, these sites can be affected by various pollution sources such as chemical fertilizers and livestock excretions. Additionally, the effects of pollution sources on groundwater quality in the sites cannot be clearly distinguished from naturally occurring backgrounds. In this study, a method was developed to select the sampling sites for groundwater quality through livestock excreta survey in order to understand the effects of pollution sources especially livestock excreta. First, the concentrations of nitrate within the radius of 200 m, 300 m, 500 m and 750 m, respectively, from the farms regarded as pollution sources in hydrogeological units were compared in 2016-2017. All the nitrate concentrations at 200 - 500 m from the farms exceeded a background concentration, 13.3 mg/L. Those at 750 m and the background concentrations measured by the Ministry of Environment were comparable. Therefore, the appropriate radius was suggested as 500 m for livestock excretions survey. In this study, the areas within 500 m from the farms could be considered under the influence of livestock excretions, while those beyond 500 from the pollution sources as background in hydrogeological units. The developed method was validated by applying it to the sites selected based on both administrative divisions and watersheds for livestock excretion survey. The average densities for the developed method were 0.82 and 0.39 points/km2, respectively, which were considered as appropriate levels according to those of the European Environmental Agency.

Optimization Power Management System for electric propulsion system (전기추진시스템용 OPMS 기법 연구)

  • Lee, Jong-Hak;Oh, Jin-Seok
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.23 no.8
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    • pp.923-929
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    • 2019
  • The stability of the propulsion system is crucial for the autonomous vessel. Multiple power generation and propulsion systems should be provided for the stability of the propulsion system. High power generation capacity is calculated for stability, resulting in economical decline due to low load operation. To solve this problem, we need to optimize the power system. In this paper, an OPMS for electric propulsion ship is constructed. The OPMS consists of a hybrid power generation system, an energy storage system, and a control load system. The power generation system consists of a dual fuel engine, the energy storage system is a battery, and the control load system consists of the propulsion load, continuous load, intermittent load, cargo part load and deck machine load. The power system was constructed by modeling the characteristics of each system. For the experiment, a scenario based on ship operation was prepared and the stability and economical efficiency were compared with existing electric propulsion ships.

A Study on Design of a Tandem AGV System with Multi-load AGVs (Multi-load AGV를 사용하는 Tandem AGV시스템 설계에 관한 연구)

  • 정병도;김경섭
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2000.04a
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    • pp.509-512
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    • 2000
  • AGV 는 자동화된 생산 시스템에 없어서는 안 되는 중요한 요소로 자리잡았다. 하지만 생산 시스템의 규모가 커짐에 따라 설계와 운영에 있어 많은 어려움이 생겼고, 이를 극복하기 위해서 새로운 형태의 AGV시스템이 제시되고 있다. 이중 대표적인 것이 Tandem AGV 시스템이다. Tandem AGV 시스템은 전체 시스템을 몇 개의 지역으로 분할하고, 하나의 지역에 한대의 차량을 할당하는 방식으로 운영의 효율성을 꾀하고 있다. 본 연구에서는 Multi-load AGV 를 사용하는 Tandem AGV 시스템을 설계하기 위한 효율적인 방법론을 제시하고자 한다.

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Research on the Development Management Basin and Goal for 3th T.W.Q on the Boundary between Metropolitan Cities/Dos Specified in Nakdong River Basin (낙동강수계 3단계 광역시·도 경계지점 목표수질 설정을 위한 관리권역 및 관리목표 설정 방법 연구)

  • Hwang, Ha Sun;Park, Ji Hyung;Kim, Yong Seok;Rhew, Doug Hee;Choi, Yu Jin;Lee, Sung Jun
    • Journal of Korean Society on Water Environment
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    • v.31 no.5
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    • pp.569-575
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    • 2015
  • The current Total Pollution Load Control (TPLC) sets the Target Water Quality (TWQ) by utilizing the delivery ratio, unit loads, and water quality modeling, it also allocates the watershed's permitted discharge load. Currently, common target pollutants of every unit watershed in TPLC are BOD and T-P. This study has reviewed the 1th and 2th of TWQ setting process for the Nakdong River 3th TWQ setting in Total Pollution Load Control (TPLC). As a result of review, 1th and 2th were divided into one management basin (mulgeum) for setting management goals. However, 3th was divided into six management basins (mulgeum, gnagjeong, geumho river, nam river, miryang river, end of nakdong river). The principle of management goal setting were to achieve the objective criteria of Medium Areas for the linkage of the water environment management policy. And Anti-Degredation (principle of preventing deterioration) were applied to the 3th TWQ. Also, additional indicators were considered in accordance with the reduction scenarios for the final management goals.

Development of the Ubiquitous-based Intelligent Digital Switchgear Panel for Home Automation (유비쿼터스 기반의 주택 자동화용 디지털 분전반 개발)

  • Ko, Yun-Seok;Kim, Ho-Yong;Yun, Seok-Yeul
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.5
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    • pp.741-747
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    • 2008
  • This paper proposes a new concept of IDSP(Intelligent Digital Switchgear Panel) which can solve the problem of the safety, the reliability and the convenience to correspond to the requirement of the general electric customer or electric power company under the ubiquitous-based home automation environments. By analyzing their requirement functions, a 32-bit micro processor is adopted as main controller to support the designed functions efficiently. The DSP-based single phase power management device is utilized to collect the electric power information and the ethernet convertor to communicate through internet among the IDSPs and the remote computer system. In the proposed IDSP, the several functions are implemented such as the earth leakage level display and waveform transmission, the electric fee display, the voltage management, the load management and the load control function. Finally, the prototype of the IDSP is made experimently based on the designed results, and then the effectiveness is verified by testing its basic functions.

Adaptive Queue Management in TCP/IP Networks (TCP/IP 네트워크에서 적응적 큐 관리 알고리즘)

  • Kim, Chang Hee
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.6 no.2
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    • pp.153-167
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    • 2010
  • Traffic conditions, in particular number of active TCP flows, change dramatically over time. The main goal of this paper is an adaptive queue management algorithm that can maintain network state of high-throughput and low-delay under changing traffic conditions In this paper, we devise Probability Adaptive RED(PARED) that combines the more effective elements of recent algorithms with a RED core. It automatically adjusts its adaptive marking function to account for changes in traffic load and to keep queue length within the desired target queue length. We simulate that PARED algorithm results in under changes in traffic load and mixed traffic load. The simulation test confirm this stability, and indicate that overall performances of PARED are substantially better than the RED and ARED algorithms.

A Study on the IPv6 Multihoming Mechanism using Loadsharing Broker.

  • Kim, Dong-Kyun;Park, Hak-Soo;Kim, Seong-Hae;Whang, Il-Sun
    • Journal of Scientific & Technological Knowledge Infrastructure
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    • s.7
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    • pp.141-148
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    • 2001
  • This paper describes a mechanisms for IPv6 multihomming with loadsharing broker, focusing on the interdomain scalability and load sharing with redundancy on IPv6 networks. Unlike currently-practiced IPv4 multihoming, this model does not impact the worldwide routing table size, also it provides inbound load sharing at site level based on router renumbering, and multiple-prefix assigning techniques of IPv6. The proposed model has four modules such as building interfaces MIB module, priority list maintaining module, load detection module, and RRP configuration module.

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Characteristics of Biochemical Oxygen Demand Export from Paddy Fields during Storm and Non-storm Period and Evaluation of Unit Load (강우시와 비강우시 BOD 유출 특성 조사 및 원단위 평가)

  • Choi, Dongho;Cho, Sohyun;Hwang, Taehee;Kim, Youngsuk;Jung, Jaewoon;Choi, Woojung;Park, Hyunkyu;Yoon, Kwangsik
    • Journal of Korean Society on Water Environment
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    • v.33 no.5
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    • pp.531-537
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    • 2017
  • The biologic Oxygen Demand (BOD) is a reliable and generally accepted indicator of water pollution by organic pollutants. Accordingly, estimation of BOD export from paddies carries important implications fwith regard to water management in rural areas. In this study, hydrology and BOD concentration were monitored during the period 2008 through 2012, in an effort to understand the characteristics of BOD export from paddy fields. The findings demonstrated that BOD load by rainfall above 50 mm. occupied about 50 % of total load, whereas the load by less than ten mm. rainfall occupied about 29 % of the total load during periods of stormy activity. It therefore seems that it could be possible to reduce the BOD load up to 29 % during storm periods, when drainage control conducted for rainfall less than ten mm.(an amount which is relatively easy to manage). The documented mean loads of storm and non-storm were $17.1kg\;ha^{-1}\;yr^{-1}$ and $11.2kg\;ha^{-1}\;yr^{-1}$, respectively. The BOD load during the significant rainfall period was similar to the renewed unit load by NIER (2014). However, there were substantial differences between unit load and actual load when the non-storm load was incorporated into the BOD load estimation from paddy fields. In view of the foregoing, it is felt that, the non-storm load needs to be further considered and managed for the successful implementation of Total Maximum Daily Load (TMDL) program.

Effects of Motion Repetition and External Load Depending on Joint Motions (관절 동작에 따른 동작 반복 및 외부 부하 영향에 관한 연구)

  • Dohyung Kee
    • Journal of the Korea Safety Management & Science
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    • v.25 no.2
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    • pp.107-111
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    • 2023
  • This study aims to empirically investigate effects of motion repetition and external load according to joint motion on discomfort through an experiment. Eighteen college students (female: 9; male: 9) participated in an experiment measuring perceived discomfort using the Borg CR10. Joint(wrist, elbow, shoulder and trunk) motion, its repetition and external load were adopted as independent variables. The results showed that all three independent variables were statistically significant on discomfort. Participants' sex also significantly affected discomfort obtained in the experiment. While the interactions of joint motion and repetition, and joint motion and external load were not significant at α = 0.05, that of motion repetition and external load was significant. Based on the experimental results, four regression equations by the joints involved were presented, which could be used as a tool for evaluating postural loads by the joints. It may be postulated that based on the results of this study, scoring systems of RULA and REBA, and those of OWAS and REBA underestimates effects of motion repetition and external load, respectively. It is expected that the results of this study will be used as a basic data for developing an observational method properly reflecting the effects of motion repetition and external load.

A Scheme of Effective Water Quality Management on Lake Okjeoung (옥정호의 효율적인 수질관리방안)

  • Lee, Yo-Sang;Kim, U-Gu
    • Journal of Korea Water Resources Association
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    • v.34 no.5
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    • pp.487-497
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    • 2001
  • Investigated data on Lake Okjeong were used for the simulation of water quality. According to the simulation results, the effective scheme of water quality management on reservoir has been proposed. It has been recognized that the water quality of Lake Okjeong is under eutrophic and mesotrophic condition even though there are seasonal variation. The water quality of lake is mainly affected by the inflow of pollutant load from watershed. Therefore, to estimate and quantify the accurate amounts of pollutants flowing into reservoir is absolutely necessary for the effective management of water quality on Lake Okjeong. When the pollutant load measured during 7 different rainy periods in 1999 was compared with total pollutant load in 1999. TN and TP measured during 7 different rainy periods showed almost 50% of total pollutant load. In case of SS, it was 72.8%. On the other hand, the rainfall amount measured during the 7 different rainy periods was about 17.5% of total rainfall amount in 1999. Release rate of TP shows 11.92 mg/L at fish farm site and 0.2∼1.9 mg/L at monitoring station of water quality on Lake Okjeong, and which is considered to be less than that of other foreign reservoirs under the circumstances of anoxic condition. For the effective management of water quality on Lake Okjeong. WASP5 water quality simulation model has been applied and verified, and the verified model was used to propose the effective scheme of water quality management. In this case, 6 different scenarios were applied, by changing the amount of inflow of pollutant load in each subbasin. The most effective scheme has turned out that pollutant load generated from Imsil and Gwanchon subbasin should be reduced, and the best way to improve the water a quality is to reduce the pollutant load at every subbasin. According to the simulation result, wastewater treatment facility should be located at every subbasin.

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