• Proceedings of the Korean Institute of Building Construction Conference
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• v.y2004m10
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• pp.87-90
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• 2004

Serious problems of the environment protection and resource exhaustion are exhibited. due to the increase of the construction materials and activation of the remodeling, recently. Especially, most of the advanced countries. recycling plan for the waste concrete is vigorously progressing. The purpose of this study is making advances in the recycling of waste concrete material for use as recycled aggregate to make secondary concrete product. Using recycled aggregates form demolished concrete, we manufactured cement bricks to experiment overall performance in Korean Standard and feasible performances. On the recycled cement, in the case of cement : aggregate is 1 : 7 is satisfied with KS F 4004 : dimensions, water absorption, compressive strength of quality of a standard. So we concluded that it has great feasibility to apply these products to construction industry.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.253-259
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• 2005

Mine is quickly decline, Nowadays, many of abandoned and closed mines. AMD is abandoned surface water by accumulated yellowboy and caused environmental pollution by amount of heavy metals. The aim of this study waste lime was mixed with the sediment to produce an aggregate far the purpose of neutralizing the acidity and stabilization the heavy metal in the aggregate structure .to pozzolan effect. The result of Waste lime and sediment mixed(5%, 10%, 20%)ration by curing days(3, 7, 38days), After 28 curing days as 5% mixed waste lime leaching solution concentration of all heavy metals is satisfied with regulation limit. Also, the result of fractionate heavy metals to stabilization as 28 curing days very decrease exchangeable and reducible type, and then increase carbonate type. With the above results, waste lime the most effective for the sediment treatment and useful for the recycling waste resource.

• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.195-199
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• 2003

BEE 802.11 Wireless LAN protocol uses fixed transmission power. It does not consider a power control mechanism based on the distance between the transmitter and the receiver in order to improve overall channel utilization. In home environment, where stations generally lie around an AP, the AP is subject to use transmission power more than it needs. And wireless LAN stations may require different minimal desired received power. If there are many adjacent BSSs in densely populated WLAN area, they might cause RF interference to one another. In this paper we focus on the improvement of aggregate utilization by mitigating RF interference among BSSs. We show that RF interference by APs can be reduced by controlling transmission power using Link Margin information. The reduced interference will then lead to the increased aggregate throughput which is efficient resource utilization.

• Journal of the Korea Society of Computer and Information
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• v.8 no.3
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• pp.40-46
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• 2003

The high-performance processors have recently employed sophisticated techniques to overlap and simultaneously execute multiple computation and memory operations. For the query processing of database management systems, those hardware characteristics are the important research issue. The latest works show that the cache miss penalty between main memory and CPU becomes new bottlenecks and the branch misprediction causes serious resource-waste. An effcient algorithm for query processing of aggregate functions considering these hardware characteristics was proposed in this dissertation.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.04a
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• pp.538-543
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• 2000

DS(Differentiated Service)에서는 RSVP와 같이 개별 flow에 대한 QoS제공이 아닌 flow들의 집합(aggregate)으로 차등적인 서비스를 제공하는 방법이다. 확장성을 고려한 이러한 방안은 광역백본망 에서와 같이 수천, 수만의 flow들에 대해 서비스를 제공하고자 할때 flow들을 집합(aggregate)화 하여 차등적인 서비스를 제공하고자 하는 것은 매우 큰 의미가 있다고 할 수 있다. 하지만 DS에서는 Token Bucket 방법을 사용하여 트래픽 스트림을 측정하는 이유로 불특정 flow에 대해 심각한 QoS손실을 야기할 수 있다. 본 논문에서는 자원공유의 공정성을 기여하기 위해 Traffic Conditioner에서 사전 모니터링 방법을 사용하고 이 모니터링 결과를 Weighted Fair Queuing의 파라메터로 사용하여 잉여 자원을 효율적으로 사용하는 방안을 제시한다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.3
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• pp.133-142
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• 2014

Recently, more focus is shift to imbalances in aggregate market supply and demand and an exhaustion of natural resources. In this situation, Electric arc furnace oxidizing slag (EAF Slag) has high application possibility as aggregate for concrete due to similar property with general aggregate. In this study, We've got the plan to assure the chemical stability of EAF Slag, and then experimentally tested the mechanical performance and durability for the fine aggregate used EAF Slag. On this test result, we suggest the application plan. At the result of this study, it shows that EAF slag would reduce the surface defect such as pop-out due to natural aging for the fixed hour and adjustment the grain size of EAF Slag. And mechanical performance and durability according to the replacement rate of concrete service, were revealed more than equal or equal compare to general aggregate. Hereafter, quality control must precede not to impede the beauty of concrete surface as assure the safety for aging and processing. And, to establish the environmental resource recycling system for by-products of steel, it should be made development of various application and guideline of quality control for the EAF slag aggregate. Moreover, it must be constantly studied all kind of engineering performance and durability for related to this study.

• Korean Management Science Review
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• v.10 no.1
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• pp.81-105
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• 1993

The objective of the paper is to develop models for determining the aggregate budget size in long-range R&D planning of KT(Korea Telecom.) and for allocating it by strategically adopted technologies for KT's TOP(Telecommunication-Oriented Paradise) Strategy. In the model of R&D budget size determination, the linear regression analysis is applied. In allocating the R&D expenditure, criteria weighting and technological importance ranking are determined by means of the Analytic Hierarchy Process(AHP) as a decision aid, along with hierarchical representation and pairwse comparisons. R&D budget analysis provides to basic data for the mid-and long-range R&D planning. The model then needs to be adjusted as the TOP project plan becomes specific. Resource allocation model for R&D based on AHP can be used to identify the importance of the technologies for TOP according to short-, mid-, and long-term perspectives without further modification. It is expected that the R&D budget analysis model works as the basis for planning R&D investment strategies and that the resource allocation model for R&D contributes to the effective use of the limited resource.

• Environmental and Resource Economics Review
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• v.20 no.2
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• pp.255-289
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• 2011

This study made linked Energy IO Table 00-05-08 of 76 sectors in intermediate sectors and analyzed structural decomposition analysis in energy consumption change in industrial sector with both by aggregate data and micro data. Structural decomposition analysis focused value added level change, value added share change of each industry, output structural change of each industry and energy intensity change of each industry as factors. Supply side model based on Ghosh inverse matrix was applied as empirical model because Korea has export driven industrial structure. Empirical results with aggregate data showed that value added change increased energy consumption and output structural change of each industry decreased energy consumption in both 2000~2005 and 2005~2008. However value added share change and energy intensity change caused opposite direction in energy consumption change with time. Policy based on aggregate data can not evaluate effort of each industry in energy efficiency and make effective results because aggregate data delete character of each industry.

• Resources Recycling
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• v.12 no.2
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• pp.11-20
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• 2003

Limestone mine waste was used as a aggregate far permeable concrete. Void ratio, continuous void ratio, coefficient of permeability, compressive strength and flexural strength of concrete were measured and then the relationship between porosity and strength properties was investigated. Void ratio, continuous void ratio and strength properties of permeable concrete were greatly influenced by the grain size of aggregate and void filling ratio in comparison with the containing ratio of limestone mine waste. Furthermore, void ratio showed a good relation with continuous void ratio, and porosity of permeable concrete indicated a good relation with strength properties also. The coefficient of permeability of permeable concrete using limestone waste was over 0.2 cm/sec and was excellent result in comparison with normal concrete. Therefore, it could be expected that the limestone mine waste would be utilized as aggregate for pavement concrete, green concrete and water resource specie concrete in the results of this study.

• Journal of the Korea Concrete Institute
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• v.21 no.3
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• pp.367-375
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• 2009

Recently, more focus is shift to imbalances in aggregate market supply and demand and an exhaustion of natural resources. In this situation, Electric arc furnace oxidizing slag (EAF slag) has high application possibility as aggregate for concrete due to similar property with general aggregate. However, it is inherent the problem which causes pop-out by free-CaO contained in slag In this study, we've got the plan to assure the chemical stability of EAF slag, and then experimentally tested the mechanical performance and durability for the fine aggregate used EAF slag. On this test result, we suggest the application plan. At the result of this study, it shows that EAF slag would reduce the surface defect such as pop-out due to natural aging for the fixed hour and adjustment the grain size of EAF slag. And mechanical performance and durability according to the replacement rate of concrete service, were revealed more than equal or equal compare to general aggregate. Hereafter, quality control must precede not to impede the beauty of concrete surface as assure the safety for aging and processing. And, to establish the environmental resource recycling system for by-products of steel, it should be made development of various application and guideline of quality control for the EAF slag aggregate. Moreover, it must be constantly studied all kind of engineering performance and durability for related to this study.