• 한국컴퓨터정보학회논문지
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• 제12권5호
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• pp.273-284
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• 2007

본 논문은 재구성가능생산시스템 환경에서 e-MarketPlace를 통한 거래상황을 도입한 주기적 검토 재고모형을 연구한다. 의사결정권자는 고객의 확률적 수요를 만족시키기 위해서 생산용량/생산량을 확장/축소하거나 e-Marketplace를 통해 긴급으로 재고를 보충/처리한다. e-MarketPlace로부터의 거래 시 재고의 보충/처리에 걸리는 리드타임은 시스템의 생산리드타임보다 짧지만, 단위거래비용(구매/판매비용)은 생산용량/생산량을 한 단위 확장/축소하는 비용보다 높기 때문에 각 대안들의 비용-리드타임간의 trade-off가 고려된다. 추가적으로 e-MarketPlace로부터 재고를 보충하거나 생산용량을 확장하는 경우 그 수량에 따른 규모의 경제를 고려하기 위해 고정 비용이 포함된다. 우리는 제안되는 모형의 최적 정책형태를 규정하기 위해 동적계획모형과 K-convexity 기법을 적용하고, base stock policy와 (s,S) type policy의 조합으로 구성된 최적 생산-재고관리 정책을 제시한다.

• 한국환경보건학회지
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• 제35권3호
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• pp.226-234
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• 2009

The main objective of this study was to evaluate the effects on shape and size, compressive strength, water absorption and heavy metals leaching with various weight mixing ratios in waste ash brick products using waste recycling MSWI(Municipal Solid Waste Incinerator) bottom ash, steel slag and waste building material. The manufacturing processes for the waste ash brick consist of screening, mixing, conveyor transmission, compaction.forming, and curing steps of raw materials. The weight mixing ratios of steel slag around bottom ash were adjusted within the ranges of 10% to 30%. The reported results show that the width and thickness of the manufactured waste ash brick could be satisfied with $90{\pm}2mm\;and\;57{\pm}2mm$, respectively which are K.S. standards of products qualities. And in case of length, only 20-Ba50Ss30, 20-Ba60Wb20 and 20-Ba50Wb30 for the mixing ratios could be satisfied with $190{\pm}2mm$ that is K.S. standards of products quality. The compressive strength and water absorption for 20-Ba50Ss30 and 20-Ba70Wb10 were over $8N/mm^2$ and below 15% respectively that are K.S. standards of manufactured waste ash brick. The results of tests for the heavy metals leaching in the all manufactured waste ash bricks are also passed to the wastes management regulations. The cost analysis of 20-Ba50Ss30 is evaluated. The manufacturing cost is evaluated 34.3 won/brick with 8 hours and 20tons of raw material per day. Incinerators with problems in bottom ash disposal can therefore derive significant benefits from the application of waste ash brick production.

• 자원리싸이클링
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• 제14권2호
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• pp.56-61
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• 2005

국내 기존의 석탄화력발전기에서 운영 중인 충수중력식 바닥재 처리시스템을 바닥재의 재활용이 가능한 건식처리시스템으로 교체하는 개선사업에 대하여 500MW${\times}$2기 발전설비를 대상으로 경제성을 분석하였다. 건식처리시스템으로의 개선 시 초기투자비는 13,415,127천원이 소요되며, 시설운영비는 연간 935,345천원이 절감될 것으로 예측되었다. 이를 기초로 경제성 평가를 수행한 결과, 개선사업 시 소요되는 초기투자비는 자본 이익률 10%에서 시설사용연한 내에 회수가 불가능하였으며, 투자이익률은 5.6%로 산정되어, 현재 국내 조건에서 개선사업은 경제성을 확보하지 못하는 것으로 평가되었다. 이는 신규발전설비에 건식처리시스템의 도입이 경제성을 확보하는 것과 유럽에서 개선사업이 경제성을 확보하는 것과 다른 결과를 보이고 있는데, 이는 회매립비 차이에 기인하는 것으로 검토되었다. 향후 국내 시장 여건의 변화에 따라 회매립비와 회판매가가 변동할 경우의 경제성 분석결과, 개선사업은 회판매가가 17,000원/톤 이상으로 상승하거나 회매립비가 15,000원/톤 이상으로 상승할 경우, 경제성을 확보할 수 있는 것으로 평가되었다.

• Nuclear Engineering and Technology
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• 제37권1호
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• pp.91-100
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• 2005

Kyung-hee Thorium Fuel (KTF), a heterogeneous thorium-based seed and blanket design concept for pressurized light water reactors, is being studied as an alternative to enhance proliferation resistance and fuel cycle economics of PWRs. The proliferation resistance characteristics of the KTF assembly design were evaluated through parametric studies using neutronic performance indices such as Bare Critical Mass (BCM), Spontaneous Neutron Source rate (SNS), Thermal Generation rate (TG), and Radio-Toxicity. Also, Fissile Economic Index (FEI), a new index for gauging fuel cycle economy, was suggested and applied to optimize the KTF design. A core loaded with optimized KTF assemblies with a seed-to-blanket ratio of 1: 1 was tested at the Korea Next Generation Reactor (KNGR), ARP-1400. Core design characteristics for cycle length, power distribution, and power peaking were evaluated by HELIOS and MASTER code systems for nine reload cycles. The core calculation results show that the KTF assembly design has nearly the same neutronic performance as those of a conventional $UO_2$ fuel assembly. However, the power peaking factor is relatively higher than that of conventional PWRs as the maximum Fq is 2.69 at the M$9^{th}$ equilibrium cycle while the design limit is 2.58. In order to assess the economic potential of a heterogeneous thorium fuel core, the front-end fuel cycle costs as well as the spent fuel disposal costs were compared with those of a reference PWR fueled with $UO_2$. In the case of comprising back-end fuel cycle cost, the fuel cycle cost of APR-1400 with a KTF assembly is 4.99 mills/KWe-yr, which is lower than that (5.23 mills/KWe-yr) of a conventional PWR. Proliferation resistance potential, BCM, SNS, and TG of a heterogeneous thorium-fueled core are much higher than those of the $UO_2$ core. The once-through fuel cycle application of heterogeneous thorium fuel assemblies demonstrated good competitiveness relative to $UO_2$ in terms of economics.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.91-92
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• 2023

With the development of technology, interest in the implementation of free-form buildings is increasing, and research on producing free-form panels is being conducted accordingly. Since free-form buildings are curved and consist of geometric shapes, there are many problems with the production technology of free-form panels that implement them. Due to the inability to reuse molds, the cost of disposal of construction waste and waste of manpower for assembly increase the construction period and construction cost. To improve these limitations, a 3D printed concrete nozzle for FCP production was developed. However, this technology is not quantitatively extruded according to the shape of the panel, and there is a problem that residues are generated. Therefore, an free-form panel extrusion experiment was conducted to analyze the limitations of existing nozzles and to analyze the requirements for the development of new concrete extrusion nozzles. Existing nozzles were unable to be quantitatively extruded, resulting in errors. Due to the weak pressure of the screw and the inability to adjust the internal pressure, detailed extrusion speed control was impossible, and residue generation in the opening and closing device seemed to be the cause. Therefore, a pump capable of quantitative concrete pressure transfer and a pressure control device for easy extrusion of concrete are required. In addition, it is judged that it is necessary to develop an opening and closing device and an extrusion device that do not generate residues. The results of this study are expected to provide information for FCP production and production and to be a basic study of technologies necessary for the production of free-form building panels.

• 한국건설순환자원학회논문집
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• 제12권2호
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• pp.222-228
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• 2024

이 연구에서는 건축물 분별해체 제도 도입에 따른 사회적 편익을 분석하고자 하였다. 이를 위하여 연면적 2,400 m²의 공동주택을 대상으로 산출된 분별해체 수익 및 비용을 토대로 국가전체의 증분수익, 증분비용, 증분이익을 도출하였다. 2,400 m²를 대상으로 분별해체 공사를 실시할 경우, 해체공사 시공비용의 증가액, 혼합폐기물의 감소로 인한 발생 폐기물 처리 비용 저감액, 분리·선별한 폐기물을 활용한 재활용으로부터 얻을 수 있는 수익을 종합적으로 검토하였을 때, 일반 해체공사와 비교하여 총 34,727천원의 비용 절감 효과가 예상됨을 확인할 수 있었다. 이를 건설폐기물 발생량이 가장 많았던 2020년을 기준으로 국가 전체적으로 환산한다면 746,782,886천원의 사회적 편익이 발생함을 추정할 수 있었다.

• 디지털융복합연구
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• 제12권9호
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• pp.255-263
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• 2014

선진국과 달리 한국에서는 낮은 처리비용 등을 이유로 원거리에 있는 폐기물 처리시설에 의료폐기물 처리를 위탁하는 것이 가능하다. 이 과정에서 위험성 때문에 의원입법으로 개정법률안이 국회에 제출되어 있다. 본 연구는 선진국과의 비교연구를 통하여 의료폐기물 관련 문제해결을 위한 효과적인 방안을 모색하는데 그 목적이 있다. 연구방법은 문헌고찰 및 법률의 비교연구를 통한 서술식 방법을 채택하였다. 외국에서는 감염성 폐기물에 대하여 발생지 인근에서 신속한 처리를 원칙으로 하면서 장거리 이동 가능성을 제한하고 다양한 기술사용을 권장하고 있는 것에서 한국과 차이를 보인다. 따라서 외국 사례와 비교하여 의료폐기물 최적의 처리방안으로 권역화 방안을 제시했다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1319-1322
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• 2003

KAERI is developing the Advanced Spent Fuel Conditioning Process (ACP) as a pre-disposal treatment process for spent fuel. Equipment used for such a spent fuel recycling and management process must operate in intense radiation fields as well as in a high temperature. Therefore, remote maintenance has a played a significant role in this process because of combined chemical and radiological contamination. Hence suitable remote handling and maintenance technology needs to be developed along with the design of the process concepts. To do this, we developed the graphic simulator for the ACP. The graphic simulator provides the capability of verifying the remote operability of the process without fabrication of the process equipment. In other words, by applying virtual reality to the remote maintenance operation, a remote operation task can be simulated in the graphic simulator, not in a real environment. The graphic simulator will substantially reduce the cost of the development of the remote handling and maintenance procedure as well as the process equipment, while at the same time producing a process and a remote maintenance concept that is more reliable, easier to implement, and easier to understand.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.363-366
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• 2004

KAERI is developing the Advanced Spent Fuel Conditioning Process (ACP) as a pre-disposal treatment process for spent fuel. In this process, the management process must operate in intense radiation fields as well as in a high temperature. Therefore, remote maintenance has played a significant role in this process. Hence suitable remote handling and maintenance technology needs to be developed along with the design of the process concepts. To do this, we developed the digital mockup for the ACP. The digital mockup provides the capability of verifying the remote operability of the process without fabrication of the process equipment. In other words, by applying virtual reality to the remote maintenance operation, a remote operation task can be simulated in the digital mockup. Through utilizing this graphic simulation in this digital mockup, general guidelines can be established for designing equipment intended for remote handling and maintenance. Also, the designer of the equipment that must be remotely maintained should ensure that there is adequate access to the process equipment. The graphic simulator will substantially reduce the cost of the develo363pment of the remote handling and maintenance procedure as well as the process equipment.

• Environmental Engineering Research
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• 제23권1호
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• pp.114-119
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• 2018

Yarn dyed wastewater has to be treated prior to disposal into the water bodies due to its high content of harmful organic compounds. In this study, the performance of Chemical Oxygen Demand (COD) removal and kinetic rate constant are investigated via hybrid electrocoagulation-Fenton in a continuous system using wastewater discharged from a yarn dyed industry in Surabaya city. The wastewater was treated in a batch mode using electrocoagulation to reduce Total Suspended Solid, followed by Fenton method in a continuous system to reduce COD level. Various Fe(II) feeding modes, molar ratio of $Fe(II)/H_2O_2$, initial pH of wastewater, and flow rate are used in this study. The results show that COD removal process obeys a pseudo-first order kinetics. At $Fe(II)/H_2O_2$ ratio of 1:10, initial wastewater pH of 3.0, and feed flow rate of 30 mL/min, the COD removal efficiency was observed to be 80%, and the kinetic rate constant is $0.07046min^{-1}$. The chemical cost for the treatment estimated to be IDR 160 per L wastewater, which is cheaper than the previously reported batch system of IDR 256/L.