• Journal of Industrial Technology
• /
• v.20 no.B
• /
• pp.55-62
• /
• 2000

The purpose of this research is to find out how the inlet angle of secondary air affects the formation of recirculation zone inside a small incinerator. A commercial code, PHOENICS, is used to simulate the flow field of an incinerator. The computational grid system is constructed by Multi-Block technique. Numerical experiments are done with the five different angles of secondary air inlet. The formation of recirculation zone is evaluated by checking velocity fields. The computational results show that recirculation zone is clearly formed from 60 degree of inlet angle and the zone of recirculation is widen as angle of recirculation is increased to $75^{\circ}$.

• Journal of Korea Society of Industrial Information Systems
• /
• v.7 no.4
• /
• pp.22-28
• /
• 2002

It has been reported that neural network with cyclic connections generates limit cycles. The dynamics of discrete time network with cyclic connections has been analyzed. But the dynamics of cyclic network in continuous time has not been known well due to its huge calculation complexity. In this paper, we study the dynamics of the continuous time network with cyclic connections and the effect of chaotic signal in the network for transitions between limit cycles.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.19 no.39
• /
• pp.193-204
• /
• 1996

본 연구는 FMC(Flexible Manufacturing Cell)에 있어 상호 간섭이 없는 부품의 흐름을 제어하기 위한 교착제거방법(Deadlock Avoidance Method)에 대한 제안으로서, 이 방법이 주요한 장점은 첫째, FMC의 환경을 쉽게 적용시킬 수 있고 둘째, 공정상의 부품에 대한 dispatching 모듈이 협력하도록 설계되어 있다는 것이다. 교착제거방법은 두 개의 모듈로 구성되어 있는데 이는 순환발견알고리즘(A Cycle Detection Algorithm)과 원료주문 정책으로서, 특이할 만한 사항은 순환발견알고리즘을 채용하더라도 원료주문정책이 잘못될 수 있기 때문에 교착제거방법에 있어서 원료주문정책은 매우 중요하다는 것이다. 이를 위하여 교착전의 N-step 교착을 제거하고, 발견할 수 있는 교착제거방법과 N-step의 사전주무정책을 제시하였다.

• Korean Chemical Engineering Research
• /
• v.44 no.5
• /
• pp.489-497
• /
• 2006

The economical efficiency of conversion of the PC (pulverized coal) firing boiler to the CFB (circulating fluidized bed) boiler which used Koran anthracite as fuel was evaluated. The economic feasibility study was also carried out with regard to maintenance of the existing PC boiler. The sensitivity of economical efficiency with variation of the electric power and coal industry and the policy of government was analyzed and compared. As a results of the evaluation, the economical efficiency of maintenance of the existing PC boiler was higher than that of conversion to the CFB boiler because of the special policy of the government for Korean anthracite. However, the conversion to the CFB boiler was more economically attractive from a point of view of effective use of energy resources and future electric power industry. Additionally, the fund support for electric power industry using Korean anthracite would be effective as changing the policy of the government.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2009.05a
• /
• pp.403-404
• /
• 2009

This study has investigated application of the industrial by-product of reject ash and recycled fine aggregate to consider the economical issue to high flowing CLSM(controled low-strength material). But this high flowing CLSM is required more binder, so it has been estimated the influence of reject ash content, use of recycled fine aggregate and crushed sand, and air content about properties of CLSM.

• Magazine of RCR
• /
• v.18 no.1
• /
• pp.20-28
• /
• 2023

기업의 ESG 활동의 일환으로 탄소중립과 순환경제의 개념을 활용한 기업의 성과를 고객에게 알리기 위하여 고품질의 전과정평가 결과에 대한 요구가 커지고 있다. 이를 위해서 LCI 데이터베이스에 대한 글로벌 요건에 맞는 고품질의 LCI 데이터베이스를 구축하고 관리하는 것이 국가적으로 중요하게 인식되고 있다. 이를 위해 UNEP는 GLAD 플랫폼을 만들었고, EU는 LCDN 플랫폼을 만들어 국제통용성을 고려한 고품질의 LCI 데이터베이스를 관리하려는 노력을 하고 있다. 국내 LCI 데이터베이스는 정부주도로 1999년부터 지속적으로 개발되어 활용되고 있지만, 국제통용성의 측면에서 볼 때, 기업의 생산현황을 반영한 최신의 일차데이터가 부족하고, LCI 데이터베이스에 포함된 목록항목들이 모든 환경영향을 충분히 평가할 수도 없으며, 데이터 정보제공의 형식인 LCI 데이터베이스 포맷이 글로벌 동향을 충분히 반영하지 못하고 있다. 이에 국제통용성을 고려한 국내 LCI 데이터베이스의 개발을 위해 산업을 대표하는 협회 또는 단체를 통해 매년 최신의 일차데이터를 확보하고, 이를 토대로 모든 환경영향을 평가할 수 있는 수준의 목록항목을 포함한 국내 LCI 데이터베이스를 개발하고, 이를 Eco-SPOLD_02 또는 ILCD 등의 최신 LCI 데이터베이스 포맷으로 관리하여야 한다.

• Environmental and Resource Economics Review
• /
• v.12 no.2
• /
• pp.347-382
• /
• 2003

The paper presents available options that Korea can adopt in an effort to promote eco-industrial development in a near future. What is missing and the reasons why Korea is behind the other countries in the area are: 1) Lack of holistic view and the integrated approach toward economy and environment in policy implementation, 2) Lack of understanding, among entrepreneurs, of the concept of productivity per input resource, and the fact that not only labor and capital productivity but also the total productivity enhancement is vital for industry's competitive edge; There has been no driving force in the market to develop economies of system integration to turn industrial wastes to valuable input resources, 3) Unsupportive regulatory system regarding the trade of by products, and 4) Lack of financing and incentive mechanism. 5) Lack of information forum. Regulatory reform should be taken for the direction that in effect increase the price of disposal and motivate firms to seek symbiotic relationship with other firms, and facilitate trade by-product between firms. Financing and incentive mechanism should be introduced in order for the industry to find easy access to the opportunities for organizing the network to transform wastes in negative value to the value added resources. Also information network should be established to provide a market for by-product exchange and public education to improve industry's environmental performance.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.8 no.3
• /
• pp.310-316
• /
• 2020

In this study, the stability and EMP shielding performance of metal-based industrial by-products aggregates with excellent conductivity and easy procurement to be used as concrete aggregates for EMP shielding are evaluated. The industrial by-products are electronic-arc-furnace oxidizing slag, copper smelting slag, and ferro-moldibdenum. The composition analysis of aggregates and aggregate stability are evaluated. As a result of the experiment, ferro-moldibdenum is shown to have l ow stability as an aggregate due to its high Free-CaO. The remaining aggregates are evaluated to be safe to use as aggregates for concrete. In addition, industrial by-products aggreagate-specimens excluding ferro-moldibdenum are shown higher compressive strength than the plain specimen. The recycle aggregates, electronic-arc-furnace oxidizing slag and copper smelting slag, are shown excellent EMP shielding performance, the EMP shielding performance is expected to increase if the average particle diameter of the aggregate is small or evenly distributed.

• Applied Chemistry for Engineering
• /
• v.26 no.4
• /
• pp.477-482
• /
• 2015

This study examined the adsorption characteristics of heavy metal ions ($Cr^{6+}$, $As^{3+}$) in an aqueous solution using recycled aggregate (RA) and recycled aggregate (RA)/steel slag (SS) composites. The RA and SS are favorable for the absorbent because it contains about 91% and 86.9%, respectively, which are some of the major adsorbent ingredients (CaO, $SiO_2$, $Al_2O_3$ and $Fe_2O_3$) for heavy metal. Kinetic equilibrium of $Cr^{6+}$ and $As^{3+}$ in RA and RA/SS composites reached within 180 min and 360 min, respectively. The kinetic data presented that the slow course of adsorption follows the Pseudo first and second order models. The equilibrium data were well fitted by the Freundlich model and showed the affinity order of $As^{3+}$ > $Cr^{6+}$. The results of $As^{3+}$ also showed that the adsorption capacity slightly increased with increasing pH from 6 to 10. Meanwhile, the adsorption capacity of $Cr^{6+}$ was slightly decreased. From these results, it was concluded that the RA and RA/SS composites can be successfully used for removing the heavy metals ($Cr^{6+}$ and $As^{3+}$) from aqueous solutions.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2008.05a
• /
• pp.1570-1576
• /
• 2008

Construction of the water-friendly facilities in the apartment complex and industrial complex became popular these days. In planning water-friendly facilities, kinds, layouts, water sources, water quality and water circulation system should be studies. In this study, several alternatives for a regional industrial complex project were studies and a most reasonal alternative was selected. A main canal across the central part of the complex is the principle facility with ponds and parks. The water source alternatives were a river nearby, a reservoir, ground water and urban water supply system. For each system, water quantity and quality, circulation system, permit and maintenance were compared. The facilities should be constructed with natural material such as rock and gravel. Average depth and velocity in the canal should be 10 cm and 0.15 m/s, respectively in order to people can feel the water flow in the canal. Based on the comparison, it is found that using the ground water, and water circulation system with storage tanks at the upper and lower ends of the canal system is the best alternative.