• Title/Summary/Keyword: supply control

Search Result 3,599, Processing Time 0.032 seconds

Supply models for stability of supply-demand in the Korean pork market

  • Chunghyeon, Kim;Hyungwoo, Lee ;Tongjoo, Suh
    • Korean Journal of Agricultural Science
    • /
    • v.49 no.3
    • /
    • pp.679-690
    • /
    • 2022
  • As the supply and demand of pork has become a significant concern in Korea, controlling it has become a critical challenge for the industry. However, compared to the demand for pork, which has relatively stable consumption, it is not easy to maintain a stable supply. As the preparation of measures for a supply-demand crisis response and supply control in the pig industry has emerged as an important task, it has become necessary to establish a stable supply model and create an appropriate manual. In this study, a pork supply prediction model is constructed using reported data from the pig traceability system. Based on the derived results, a method for determining the supply-demand crisis stage using a statistical approach was proposed. From the results of the analysis, working days, African swine fever, heat wave, and Covid-19 were shown to affect the number of pigs graded in the market. A test of the performance of the model showed that both in-sample error rate and out-sample error rate were between 0.3 - 7.6%, indicating a high level of predictive power. Applying the forecast, the distribution of the confidence interval of the predicted value was established, and the supply crisis stage was identified, evaluating supply-demand conditions.

An Analysis of Production and Marketing Control Effect of Aqua-cultured Flounder Using Supply and Demand Models (수급모형을 이용한 양식넙치의 생산 및 출하조절 효과분석)

  • Ko, Bong-Hyun
    • The Journal of Fisheries Business Administration
    • /
    • v.47 no.4
    • /
    • pp.65-75
    • /
    • 2016
  • The purpose of this study was to analyze the production and marketing control effects of aqua-cultured flounder required for stable income growth of aqua-cultured household. We analyzed the supply and demand structure of cultured flounder using the partial equilibrium model approach. And we estimated the optimal yield of cultured flounder and analyzed the effect of marketing control through constructed model. The main results of this study are summarized as follows. First, the fitness and predictive power of the estimated model showed that the RMSPE and MAPE values were less than 5% and Theil's inequality coefficient was very close to 0 rather than 1. It was evaluated that the prediction ability of the aqua-cultured flounder supply and demand model by dynamic simulation was excellent. Second, dynamic simulation based on policy simulation was conducted to analyze the price increase effect of production and shipment control of cultured flounder. As a result, if the annual production volume is reduced by 1%, 5%, and 10% among 32,852~37,520 tons, it is analyzed that the price increase effect is from 1.2% to 12.5%. Finally, this study suggests that the production and marketing control can increase the price of aqua-cultured flounder in the market. In this paper, we propose a policy implementation of the total supply system instead of conclusions.

Design of Magneto-rheological Fluid Based Device (자기유변유체를 이용한 공학 장치의 설계)

  • Kim, Jeong-Hoon;Lee, Chong-Won;Jung, Byung-Bo;Park, Young-Jin;Cao, Guangzhong
    • Proceedings of the KSME Conference
    • /
    • 2001.11a
    • /
    • pp.544-549
    • /
    • 2001
  • The effect of power supply voltage on the performance limits in a laboratory Magneto-rheological fluid based device was identified by experiments. It suggests that the frequency range of motion for control be limited by the voltage attenuation due to the coil inductance and the maximum power supply voltage set for practical use of MRF devices. In this work, the magnetic and electrical characteristics of MRF device are investigated and a design procedure is formulated to achieve the desired performance for a given power supply.

  • PDF

A FUZZY PID Control of Supply Duct Outlet Air Temperature for PEM (FUZZY PID 방법을 이용한 개별 공조시스템의 급기온도 제어)

  • 장영준;박영철;정광섭;한화택;이정재
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.14 no.4
    • /
    • pp.278-284
    • /
    • 2002
  • The work presented here provides a control of the supply duct outlet air temperature in PEM (personal environment module) using fuzzy PID controller. In previous work, PID control systems were used, but the result shows that the outlet air temperature and electric heater regulating voltage were oscillated. Fuzzy PID control systems are designed to improve the system response obtained using PID control and implemented experimentally Also, PID controller and fuzzy controller without PID logic are provided to compare the result with that of the fuzzy PID controller. Data obtained shows that the fuzzy PID control system satisfies the design criteria and works proper1y in controlling the supply air temperature. Also it has bettor performance than the previous result obtained using PID control.

A Study on the Required Supply Water Temperature Calculating Method for the Control of Multizone Radiant Floor Heating System (멀티존 온돌난방제어를 위한 필요공급온수온도 산출법에 관한 연구)

  • Choi, Jeong-Min;Lee, Kyu-Nam;Ryu, Seong-Ryong;Kim, Yong-Yee;Yeo, Myoung-Souk;Kim, Kwang-Woo
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.19 no.1
    • /
    • pp.77-85
    • /
    • 2007
  • One of the most common approaches to achieve better thermal comfort with the radiant floor heating system is supply water temperature control, which is that supply water temperature is varied with outdoor air temperature. But the application of this control method was not easy, because there has been no way to determine the supply water temperature. So in this study, a comprehensive, yet simple calculation method to find out the required supply water temperature is suggested by combining the building heat loss equation and the heat emission model of hydronic radiant floor heating system for single zone. And then using this calculation method, the multizone control method is suggested and confirmed through the thermal simulation. It is shown that indoor air temperature is stably maintained around the set point.

Characteristics and control of intermittent flow in water distribution systems due to restricted supply (상수도관망에서 제한급수에 따른 간헐적 흐름의 특성 및 제어)

  • Yang, Kangseung;Kim, Donghong;Jung, Kwansoo;Kim, Juhwan
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.28 no.1
    • /
    • pp.1-11
    • /
    • 2014
  • The water distribution system should be invariably operated on continuous pattern for 24 hours a day. Occasionally, it is not practically possible to operate for 24 hours due to water shortage or financial constraints. Therefore an intermittent water supply is unavoidable in water shortage area and developing countries. But the intermittent water supply can introduce large pressure forces and rapid fluid accelerations into a water supply network. These disturbances may result in new pipe failure, leakage and secondary contamination. This paper proposed an improvement methodology to prevent the disturbances by intermittent water supply. For the study, the hydraulic variation of intermittent flow in water distribution system was measured and analyzed in the field by comparing with simulation of hydraulic model. Installations of control valves such as, pressure reducing and sustaining and air valves were employed for pressure and flow control. The effectiveness of the methods are presented by comparing hydraulic conditions before and after introducing the proposed solutions.

A Study on the Method of Estimating Optimum Supply Water Temperature Considering the Heating Load and the Heat Emission Performance of Radiant Floor Heating Panel (난방부하와 온수온돌의 방열성능을 고려한 적정 공급온수온도 산출방법에 관한 연구)

  • Choi, Jeong-Min;Lee, Kyu-Nam;Ryu, Seong-Ryong;Kim, Yong-Yee;Yeo, Myoung-Souk;Kim, Kwang-Woo
    • Proceedings of the SAREK Conference
    • /
    • 2006.06a
    • /
    • pp.795-800
    • /
    • 2006
  • A common approach to achieve better thermal comfort with hydronic radiant floor heating system is supply water temperature control. This is the control method through which supply water temperature is varied with outdoor temperature. In this study, a comprehensive, yet simple calculation method to find optimum supply water temperature is evaluated by combining heat loss from the building and heat emission from the hydronic radiant floor heating system. And then the control performance of suggested calculation method is confirmed through experiment. It is shown that indoor air temperature is stably maintained around the set point.

  • PDF

Mini PC control system for BYG type water supply units (BYG형 급수기의 MINI PC 제어 시스템)

  • 박용규;강영모
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1993.10a
    • /
    • pp.1167-1171
    • /
    • 1993
  • A highly efficient hydropneumatic water supply system type BGY is designed and built in accordance with ISO standard. The technical features of BYG type pump unit can be summarized as follows: - reduce hydropneumatic tank capacity at the ratio of 1/10 - 1/30 compared with conventional method. - ISO standard pumps can be used. - the development of highly efficient water supply system type BYG is based on long-term experiences with the proven constant pressure water supply technique which minimize pressure fluctuation, rapid pilsation, etc. The text contains the operation principle of BYG type water supply system, introduction of closed cycle control process focused on Mini PC and experimental results of type BYG-IVS-90x45.

  • PDF

Coordination of Component Production and Inventory Rationing for a Two-Stage Supply Chain with a VMI Type of Supply Contract (적시 부품 공급 계약을 갖는 두 단계 공급망에서 부품 생산과 재고 분배의 통합적 구현)

  • Kim, Eun-Gab
    • Journal of the Korean Operations Research and Management Science Society
    • /
    • v.37 no.2
    • /
    • pp.45-56
    • /
    • 2012
  • This paper considers a supply chain consisting of a component manufacturer and a product manufacturer. The component manufacturer provides components for the product manufacturer based on a vendor-managed inventory type of supply contract, and also faces demands from the market with the option of to accept or reject each incoming demand. Using the Markov decision process model, we examine the structure of the optimal production control and inventory rationing policy. Two types of heuristics are presented. One is the fixed-buffer policy and the other uses two linear functions. We implement a computational study and present managerial insights based on the observations.