• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2007년도 춘계학술논문 발표대회
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• pp.63-66
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• 2007

This study investigates the fire resistance properties of high strength concrete, around 60MPa class, designed with various admixture types and fiber content. Test showed that the increase of fiber content decreased the fluidity and slightly inclined the air content of fresh concrete. However, the fiber content in concrete did not affect the compressive strength. For the addition of admixture, specimens adding the shrinkage-reducing-agent (SR) indicated the strength value at 70MPa, which is followed by incorporating silica fume (SF) at 66MPa, the combination of expansive admixture (EA) and SR at 63MPa, only EA at 59MPa, blast furnace slag (BS) at 58MPa and fly ash (FA) at 50MPa in an order. After completing the fire test, all specimens adding 0.05vol.% of polypropylene fiber exhibited protection of spatting, except for the specimens incorporating loft of SF and incorporating 20% of SF with only SR and the combination of EP and SRA, respectively. Therefore the most effective result of this study was shown in the specimens incorporating love of FA and 30% of BS and incorporating 20% of SF with 5 % of EA. It is expected that this test results will be crucial references in near future to develope the spatting resistance method of high strength concrete.

• 한국소음진동공학회논문집
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• 제15권6호
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• pp.706-711
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• 2005

Torsional oscillations of a system incorporating a Hooke's joint are investigated by studying a simple similar nonlinear 2-degree-of-freedom model, which has linear and quadratic nonlinear parametric excitations. The simple system is identified to have the possibilities of primary, sub harmonic and combination resonances. The case of simultaneous primary and combination resonances is selected for perturbation analysis to have the reduced amplitude-equations of motion. The same procedure is applied to the system incorporating a Hooke's joint.

• Computers and Concrete
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• 제17권2호
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• pp.255-269
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• 2016

The waste glass sludge is a waste produced in the glass industry. It is in a dust form and disposed with water. In the disposal process, various cohesive agents are incorporated in order to precipitate the glass particles efficiently. In this paper, we investigate the pozzolanic reaction of the waste glass sludge incorporating precipitation additives experimentally. The consumption of calcium hydroxide, the setting time and the compressive strength and the pore structure were tested for two different types of the waste glass sludge depending on whether precipitation additives were used. It was found that the waste glass sludge incorporating the precipitation additives had a higher pozzolanic potential than the reference waste glass sludge without precipitation additives.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2006년도 추계학술대회
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• pp.161-164
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• 2006

The sales of consumer durables are composed of first time purchases and replacement purchases. Since the sales for most mature durable products are dominated by replacement sales, it is necessary to develop a model incorporating replacement component of sales in order to forecast total sales accurately. Several single product diffusion models incorporating replacement demand have been developed, but research addressing the multi-product diffusion models has not considered replacement sales. In this paper, we propose a model based on consumer choice behavior that simultaneously captures the diffusion and the replacement process for multi-product relationships. The proposed model enables the division of replacement sales into repurchase by previous users and transition purchase by users of different products. As a result, the model allows the partitioning of the total sales according to the customer groups (first-time buyers, repurchase buyers, and transition buyers), which allows companies to develop their production and marketing plans based on their customer mix. We apply the proposed model to the Korean automobile market, and compare the fitting and forecasting performance with other Bass-type multi-product models.

• 한국농공학회지
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• 제40권5호
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• pp.59-67
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• 1998

The object of this study is to investigate the strength characteristics and the freeze-thaw resistance of high strength concrete incorporating fine blast furnace slag. Major experimental variables were the water/cement ratio, maximum size of coarse aggregate, and cement types such as ordinary portland and slag cement. The results were as follows ; The workability of fresh concrete incorporating fine blast furnace slag was better than that of OPC(ordinary Portland cement) in terms of slump. The freeze-thaw resistance showed better than that of OPC, keeping more than 90% of relative modules of elasticity after 506 cycles and showing only a hair crack at surface without serious damage. Thus, the fine blast furnace slag might be recycled at concrete to make high strength concrete at fields.

• East Asian mathematical journal
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• 제36권2호
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• pp.317-330
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• 2020

The purpose of this action research project was to study the effects of incorporating coding into the middle school math classroom affected student dispositions with math and their understanding of mathematical concepts. The project, involving a total of 107 US middle school students, used five data sources to examine these effects: a survey, a chart measuring student engagement, a pre- and post-assessment before and after the coding project, and teacher observation with reflection forms. After analyzing the data, it was found that incorporating coding into the middle school math classroom could have a positive impact on student math dispositions and their understanding of math concepts.

• Structural Engineering and Mechanics
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• 제69권1호
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• pp.77-93
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• 2019

Although much research has been carried out using recycled aggregates sourced from normal strength concrete, most of the buildings to be demolished are constructed with low strength concrete. Therefore, the properties of the concrete incorporating recycled aggregates, sourced from the waste of structural elements cast with low strength concrete, were investigated in this study. Four different concrete mixtures were designed incorporating natural and recycled aggregates with and without fly ash. The results of the mechanical and durability tests of the concrete mixtures are presented. Additionally, full-scale one-way reinforced concrete slabs were cast, using these concrete mixtures, and subjected to bending test. The feasibility of using conventional reinforced concrete theory for the slabs made with structural concrete incorporating recycled aggregates was investigated.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.285-288
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• 1997

In this paper, the dynamics of actuators for generating the input of plants is considered in a design of the variable structure systems. While the input for plants is usually implemented by means of a certain actuator, the actuator dynamics is not incorporated in most of the VSS researches until now. The control algorithm of a VSS incorporating actuator dynamics is presented, and the simulation is given to show the usefulness of the algorithms.

• Journal of electromagnetic engineering and science
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• 제5권2호
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• pp.92-96
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• 2005

This paper presents a novel microwave oscillator incorporating a simple microstrip ring type resonant cell as its terminating resonance component. Reduced chip size, higher dc-ac power efficiency, superior harmonic characteristics can be achieved from the introduction of a compact microstrip ring resonator cell. The oscillator provides a second harmonic suppression of 26.51 dB and the output power of 2.046 dBm at 2.11 GHz.

• 한국도서관정보학회지
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• 제21권
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• pp.57-86
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• 1994

The purpose of the study is to understand the research trends in the hypertext information retrieval. Around 30 related papers were investigated, from which three distinctive streams of research trends are grasped: 1) a trend of incorporating the traditional retrieval models, especially the query-based searching model into the hypermedia system. 2) a trend of a n.0, pplying the hypermedia system as an interface to the OPAC system, 3) a trend of incorporating the artificial intelligence techniques into the hypermedia techniques. The research on the hypermedia is going on, and the research directions will be increasingly intend to incorporate the traditional retrieval models and artificial intelligence techniques into the hypermedia system.