• 제목/요약/키워드: 이월

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Environment R&D Incentives with Emission Banking and Borrowing in a Cournot Model (쿠르노 경쟁하의 배출권 이월 및 차입과 감축기술개발투자)

  • Jeong, Kyonghwa;Shim, Sunghee
    • Journal of Environmental Policy
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    • v.14 no.4
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    • pp.63-101
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    • 2015
  • Banking and borrowing under the ETS may affect the low carbon technology investment level. If the indirect implementation measures are allowed, firms can gradually adjust their carbon reduction costs between implementation periods based on their carbon reduction costs and emission price forecasts. This implies that banking and borrowing may reduce or increase the level of low carbon technology R&D investment. In an oligopoly market, the effects of the measures are quite different from the ones in a perfectly competitive market. This is because the indirect implementation measures can shift market competition in Cournot competition model. The effects of banking and borrowing on the carbon reduction R&D investments depend on emission reduction costs, marginal production costs, discount rate, initial free allocation, and the cost reduction effects of R&D investment.

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Evaluation of Carryover Contamination on Autopipetting System (자동분주기의 이월오염 평가)

  • Lee, Hyun-Ju;Min, Gyung-Sun;Shin, Sun-Young;Woo, Jae-Ryong;Lee, Ho-Young
    • The Korean Journal of Nuclear Medicine Technology
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    • v.13 no.3
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    • pp.189-192
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    • 2009
  • Purpose: Autopipetting system is an efficient automated equipment pipetting patient samples and reagents for rapid and accurate test. However, it can cause carryover between high concentration sample and low concentration sample. We evaluated carryover contamination of TECAN freedom Evo 100 autopipetting system. Materials and Method: We studied carryover contamination of $\alpha$-fetoprotein (AFP) and carcinoembryonic antigen (CEA) test on TECAN freedom Evo 100 autopipetting system. Very low concentration control samples were pipetted for comparison to the contaminated very low concentration samples. Then, The contaminated very low concentration samples were pipetted following the high concentration samples were pipetted alternately. The difference of low concentration samples represents carryover. The target value to decide carryover was 1ppm (parts per million). Results: For AFP, the mean values of the uncontaminated control samples and the contaminated samples were less than 0.6 IU/mL (the l imit of detection (LoD)). Carryover did not occur even though the high concentration sample which value was 650000 IU/mL. For CEA, the values of the low concentration control samples and the contaminated samples were less than 0.2 ng/mL (LoD). Carryover did not occur even though the high concentration sample which value was 65,000 ng/mL. Conclusions: Sample carryover was not found on TECAN freedom Evo 100 autopipetting system for AFP, CEA. However, carryover is a potential problem with automated instruments and robotic pipetting systems. Therefore, Clinical laboratories must periodically verify carryover contamination for the accurate and confidential test results.

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Nonlinear Optimization Analysis of the Carryover Policy in the 2nd Compliance Period of the Korean Emissions Trading Scheme (배출권거래제 2차 계획기간 중 이월한도 정책에 대한 비선형최적화 분석)

  • Jongmin Yu;Seojin Lee
    • Environmental and Resource Economics Review
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    • v.32 no.3
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    • pp.149-166
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    • 2023
  • The emissions trading system, introduced to reduce greenhouse gas emissions, experienced a sharp increase in emission allowance prices during the second plan period (2018-2020), which led to an increase in the demand for smooth supply and demand of emission allowances, while suppliers anticipating a shortage of emission allowances in the future did not participate in trading. Therefore, the authority temporarily revised the guidelines to ensure that the amount of allowances carried forward is proportional to the trading volume as a market stabilization measure. Through an optimization process using a dynamic nonlinear mathematical model, this paper analyzes the impact of the government's intervention on the carryover policy on GHG emission reductions and emission allowance market prices. According to the simulation analysis results, banking regulations could cause a decline in prices during the regulation period, even though the initial policy was predicted to be adopted.

Base-stock Policies for N-stage Serial Inventory Systems with a Normal Distribution (정규분포를 갖는 N차 시리얼 시스템에서의 기초 재고 정책)

  • 김준석;권익현;김성식
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2004.10a
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    • pp.578-581
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    • 2004
  • 본 연구에서는 수요가 정규분포의 형태를 따르는 N차 시리얼(serial) 시스템을 대상으로 한다. 최상위 노드는 상위의 공급자로부터 받고자 하는 물량을 제한 없이 받을 수 있으며 하위 노드로 이러한 물량을 공급하게 된다. 최하위 노드에서는 고객의 직접적인 수요가 발생하고 만족시키지 못한 수요는 다음 기간으로 이월된다. 이러한 환경 하에서 전체시스템에서 발생하는 재고유지 비용(holding cost)과 재고이월 비용(backorder cost)의 합을 최소화하는 각 노드별 최적의 기초 재고 수준(base stock level)을 결정하는 문제를 다룬다. 본 논문에서는 모의실험과 계층 재고(echelon stock)의 개념을 통해 수요 분포 내의 적절한 분위수(quantile)를 결정하는 접근방법으로 각 노드의 기초 재고 수준을 구하는 방안을 제시하고자 한다.

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A Comparison of BLS Non-Response Adjustment and Cross-Wave Regression Imputation Methods (BLS 무응답 보정법을 이용한 대체법과 이월대체법에 관한 연구)

  • Lee, Sang-Eun;Shin, Key-Il
    • The Korean Journal of Applied Statistics
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    • v.23 no.5
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    • pp.909-921
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    • 2010
  • Cross-wave regression imputation and carry-over imputation method are generally used in the analysis of panel data with missing values. Recently it is known that the BLS non-response adjust method has good statistical properties. In this paper we show that the BLS method can be considered as an imputation method with a similar formula of a ratio-estimator. In addition, we show that the carry-over imputation and BLS imputation are approximately the same under the assumption that data follow a non-stationary process with drift. Small simulation studies and real data analysis are performed. For the real data analysis, a monthly labor statistic (2007) is used.

Comparisons of Imputation Methods for Wave Nonresponse in Panel Surveys (패널조사 웨이브 무응답의 대체방법 비교)

  • Kim, Kyu-Seong;Park, In-Ho
    • Survey Research
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    • v.11 no.1
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    • pp.1-18
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    • 2010
  • We compare various imputation methods for compensating wave nonresponse that are commonly adopted in many panel surveys. Unlike the cross-sectional survey, the panel survey is involved a time-effect in nonresponse in a sense that nonresponse may happen for some but not all waves. Thus, responses in neighboring waves can be used as powerful predictors for imputing wave nonresponse such as in longitudinal regression imputation, carry-over imputation, nearest neighborhood regression imputation and row-column imputation method. For comparison, we carry out a simulation study on a few income data from the Korean Welfare Panel Study based on two performance criteria: predictive accuracy and estimation accuracy. Our simulation shows that the ratio and row-column imputation methods are much more effective in terms of both criteria. Regression, longitudinal regression and carry-over imputation methods performed better in predictive accuracy, but less in estimation accuracy. On the other hand, nearest neighborhood, nearest neighbor regression and hot-deck imputation show higher performance in estimation accuracy but lower predictive accuracy. Finally, the mean imputation shows much lower performance in both criteria.

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