• 산업경영시스템학회지
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• 제38권3호
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• pp.159-168
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• 2015

Aggregate Production Planning determines levels of production, human resources, inventory to maximize company's profits and fulfill customer's demands based on demand forecasts. Since performance of aggregate production planning heavily depends on accuracy of given forecasting demands, choosing an accurate forecasting method should be antecedent for achieving a good aggregate production planning. Generally, typical forecasting error metrics such as MSE (Mean Squared Error), MAD (Mean Absolute Deviation), MAPE (Mean Absolute Percentage Error), and CFE (Cumulated Forecast Error) are utilized to choose a proper forecasting method for an aggregate production planning. However, these metrics are designed only to measure a difference between real and forecast demands and they are not able to consider any results such as increasing cost or decreasing profit caused by forecasting error. Consequently, the traditional metrics fail to give enough explanation to select a good forecasting method in aggregate production planning. To overcome this limitation of typical metrics for forecasting method this study suggests a new metric, WACFE (Weighted Absolute and Cumulative Forecast Error), to evaluate forecasting methods. Basically, the WACFE is designed to consider not only forecasting errors but also costs which the errors might cause in for Aggregate Production Planning. The WACFE is a product sum of cumulative forecasting error and weight factors for backorder and inventory costs. We demonstrate the effectiveness of the proposed metric by conducting intensive experiments with demand data sets from M3-competition. Finally, we showed that the WACFE provides a higher correlation with the total cost than other metrics and, consequently, is a better performance in selection of forecasting methods for aggregate production planning.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.368-371
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• 2004

It analyzes the quality of the fine aggregate which is reproduced through a dry production process with cyclone and a wet production process. The conclusions of the study are as follows. 1. The recycled fine aggregate through the dry production process with cyclone shows the low rate of absorption and impurity content after the cyclone process. It shows that its density is 2.37, absorption rate is 4.8 and stability is $5.1\%$ and less. Therefore, it satisfies the standards of KS F 2573(recycled aggregate for concrete) as the first grade. 2. The recycled fine aggregate through the wet production process shows the low rate of absorption and foreign substance content after the process of wash and dehydration. It shows that its density is 2.40, absorption rate is 3.12 and stability is $3.2\%$ and less. Therefore, it satisfies the standards of KS F 2573(recycled aggregate for concrete) as the first grade.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.271-272
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• 2018

As the supply and demand of natural aggregate becomes more difficult in the domestic construction site continuously, many studies related to the recycled aggregate produced in the construction waste are going on. However, because of the safety and performance of the recycled aggregate, it is not used as aggregate for the structure, and it is mainly used as a nonstructural material. In addition, as the "recycled aggregate quality standard" has been revised in 2017, quality standards for various properties of recycled aggregate have been adjusted, and production technology suitable for recycled aggregate quality standards for concrete is needed. In this study, to improve the quality of recycled aggregate, we applied multistage wind pressure treatment method to the existing recycled aggregate production facility and compared the density, absorption rate, particle size before and after recycled aggregate treatment. As a result, quality criteria in various properties were analyzed satisfactorily.

• 한국건설순환자원학회논문집
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• 제9권4호
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• pp.483-491
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• 2021

본 연구는 순환골재의 고품질 사용 활성화를 위해 품질확보 기술의 뒷받침을 전제로 하여 순환골재의 활용에 따른 건설산업의 경제적 효과 및 순환골재 생산 산업의 가치 증대 영향을 분석을 목적으로 한다. 이에 고품질 순환골재 활용을 통해 얻을 수 있는 레미콘 생산비용을 순환골재 품질기준에서 권고한 순환골재 적용 비율에 따라 분석하고, 국내 레미콘 산업규모와 순환골재 물량 충족률을 파악하여 일반레미콘과 순환골재 적용 레미콘 산업의 경제적 효과를 분석하였으며, 비용 편익 분석법을 활용하여 고품질의 순환골재 생산 및 판매에 따른 편익을 검토하였다. 그 결과 레미콘 생산비용은 적용 비율에 따라 2.3~16.2%의 절감효과를, 순환골재 활용에 따른 건설 산업의 경제적 효과는 약 1,068~1,426억 수준을, 순환골재 생산 산업의 가치 증대 영향은 약 1.22배 편익을 발생시켰다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.517-520
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• 2006

The production of recycling aggregate is used to process in the crushing that recycling aggregate isn't perfect the concrete aggregate in Korea. This study is examine to the properties of recycling aggregate used method of trituration. Test item is the fineness, density and percent of absorptance, solid volume percentage of aggregate. The result is that first, the method of trituration is excellent to increase the time of trituration and steel ball but decrease washing water. Second, method of trituration is improve to the properties of recycling aggregate but aggregate of production is irregularity. And method of trituration have to study of the many test items.

• Environmental Engineering Research
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• 제21권3호
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• pp.241-246
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• 2016

This paper discusses the influence of organic matter contained in aggregate on the emission characteristic of ammonia ($NH_3$) from cement mortar. $NH_3$ can be released to indoor-outdoor environment through diffusion in mortar (or concrete) and have resulted in the increasing air pollution, and especially well known as a harmful gas for the human body. The concentration of $NH_3$ released from cement concrete was then compared to the contents of organic matter contained in the aggregate. The result indicates that the contents of organic matter in the aggregate significantly differ with types of aggregate from different areas of production. The organic matter becomes organic nitrogen through the process of microbial breakdown for a certain period and pure ammonium ion ($NH_4{^+}$) is produced from the organic nitrogen. The $NH_4{^+}$ was reacted with alkaline elements in the cement and released as $NH_3$ from cement concrete through a volatile process. The released $NH_3$ was proportional to the contents of $NH_4{^+}$ adsorbed in the aggregate from different areas of production and the concentrations of $NH_3$ emission from cement mortar according to the aggregate differ by more than 4 times.

• 대한산업공학회지
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• 제2권1호
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• pp.93-100
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• 1976

Given a fixed production process and facility capacity, the ability to respond to market fluctuations in terms of changes in production, work force, and inventory is the major task of production management. The costs involved are primarily payroll (regular and overtime), inventory carrying, and hiring and firing. The magnitude of these costs is usually a significant portion of the operating costs of the firm and consequently a small percentage saving due to astute aggregate scheduling can mean substantial absolute saving. At least three demonstrably optimal techniques have been developed for solving this aggregate scheduling problem. These three optimal are apparently LDR, PPP, and SDR. By combining these three different approaches, another optimal solution was obtained by me. I call this CDR (Combined Decision Rule). This approach appears to be useful. This approach may be generalizable to aggregate scheduling involving a short term resources.

• 자원환경지질
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• 제57권2호
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• pp.129-141
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• 2024

본 연구는 지역산업연관표를 이용하여 생산-생산 승수를 도출하고 비금속광물 부문과 콘크리트 제품 부문을 통해 골재의 유발효과를 추정하였다. 유발효과를 파악할 수 있도록 지역산업연관표를 활용하여 분석을 진행하였다. 골재의 유발효과를 도출함에 있어 지역산업연관표를 이용하는 것은 부문분류 문제로 인해 어려움이 있는데, 본 연구는 골재를 포함한 비금속광물 부문을 골재로 간주한 분석과 골재생산의 대부분을 수요하는 콘크리트 제품 부문을 분석함으로써 부문분류 제약으로 인한 난점을 완화하고자 하였다. 산업연관효과를 추정하는 과정에서 골재의 생산감소 상황을 전제해 진행하였으며, 콘크리트 제품 부문을 분석하는 과정에서는 골재 생산감소로 인한 콘크리트 제품 생산감소의 효과, 즉 골재 1단위 생산감소는 콘크리트 제품 부문 0.8511단위의 생산감소를 전제로 분석하였다. 지역산업연관표가 구분하고 있는 17개 광역시도에 대해 자기지역 내 및 지역간 유발효과를 산출하였다. 골재 생산감소로 인해 자기지역에서 발생하는 생산감소 효과는 지역별 평균 1.28의 유발효과를 보였으며, 타지역의 골재 생산감소로 인한 생산감소 효과는 지역별 평균 0.10의 유발효과를 보였다. 취업효과도 산출하였는데, 지역별 골재 및 콘크리트 제품 부문의 규모에 따른 차이를 나타낼 수 있도록 10% 생산감소 상황을 전제하여 취업효과를 산출하였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 춘계 학술논문 발표대회
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• pp.46-47
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• 2013

This study investigates the effect of a grading of aggregate on the properties of concrete. It is a common sense in Korea that the production of coarse aggregate in ready mixed concrete industry excludes particular aggregate size ranged from 5 mm to 13 mm for saving the production cost. This causes a gap grading of the aggregate for concrete, which can lead to the increase of unit water, the development of drying shrinkage-induced crack and the reduction of compressive strength. In this study, conventional aggregate obtained from a ready mixed concrete factory and the aggregate with a modified grading produced in lab. condition were prepared. Results showed that a good grading of aggregate (i.e., the ratio of 5~13 mm and 13~25 mm is 6 to 4) produced in the lab. condition significantly improved the slump and the compressive strength of the concrete.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 추계 학술논문 발표대회
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• pp.41-42
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• 2015

The concrete aggregate generates carbon dioxide in production but its demanding is gradually increased in accordance with the depletion of natural resources. Therefore we evaluated compatibility and basic physical properties of Silicon manganese slag generated in iron production as an applicable concrete aggregate. In our test, the silicon maganese slag shows 2.8g/㎥ of density in 10mm of maximum particle size similar to a natural aggregate, and its absorption rate was 0.3% similar to the electric furnace slag. Unit volume weight and ratio of absolute volume was respectively 2,001㎏/㎥ and 51%. Strength properties of Silicon manganese slag will be evaluated with further studies and experiments.