• Korean Journal of Cognitive Science
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• v.2 no.1
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• pp.51-72
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• 1990

This study investigated the effects of macrostructure on discourse processing. In this study, three different story were employed to form macrostructures on different times, and reading time, sentence verification time and free recall rate were measured as dependent vari- ables. The results showed that forming the macrostructure influenced the reading and verification times and the recall rate. The results were interpreted to indicate that the macrostructure is important to comprehend and recall the stories, and that the story grammars, hierarchies of story schema and causal relation of sentences affect the comprehension and recall through their interaction in macrostructure.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.608-609
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• 2006

The deformation behavior under three-point bend test was found to depend on the loading uniformity and the macrostructure for SiC reticulated porous ceramics (RPCs). However, this dependence of loading uniformity is alleviated by improved macrostructure with fewer flaws and clogged pores. Even, this dependence becomes less important as the struts become thicker and stronger. The bend result of RPCs with highly uniform macrostructure is in excellent agreement with the GA (Gibson and Ashby) model, but the one with un-uniform macrostructure deviates from the GA model, suggesting that the macrostructure plays an important role in deformation behavior of RPCs under bend.

• Economic and Environmental Geology
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• v.19 no.spc
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• pp.97-102
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• 1986

Concepts on mineral association, mineral paragenesis, and mineralization stage relating to macrostructures of vein filling in ore veins are briefly discussed. As an example of plutonic ore vein, macrostructures of vein filling of plutonic tungsten-tin-copper vein at the Ohtani mine, Kyoto Prefecture, Japan, one of representatives of plutonic tungsten-tin vein related genetically to acidic magmatism of late Cretaceous in the Inner zone of Southwest Japan, are examined. Based on macrostructures of vein filling, three major mineralization stages, are distinguished by major tectonic breaks. Sequence of mineralization, characteristic features of each mineralization stage, and variations of filling temperature and salinity ranges of fluid inclusions in minerals from stage I to stage III are summarized.

• Journal of Welding and Joining
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• v.32 no.1
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• pp.34-39
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• 2014

There are so many difficulties of melt bonding mainly applied for hull construction of a aluminum alloy small boat. For resolving this problem, Friction stir welding(FSW) in non-melting solid state welding Process generally is applied in the transport industry. This paper is studied the joining strength characteristics and macrostructure according to dissimilar aluminium 5000/6000 alloy joining for a small boat applied for this FSW technology. It is reported that difference of joining strength in accordance with the direction of rotation in case of friction stir welding between dissimilar metals(Al/Cu, Al/Fe) is also highly large. In this study, Test is carried out by making the specimen according to the direction of rotation of dissimilar aluminium alloy joining.

• Journal of Welding and Joining
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• v.29 no.6
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• pp.56-64
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• 2011

Friction stir spot welding between 5454 aluminum alloy sheets with the different thicknesses of 1.4 and 1.0 mm was performed. In the welding process, the tool for welding was rotated ranging from 500 to 2500, and plunged to the depth of 1.8 mm under a constant tool plunge speed of 100 mm/min. And then, the rotating tool was maintained at the plunge depth during the dwell time ranging from 0 to 7 sec. The pull-out speed of the rotating tool was 100 mm/min. The increase of tool rotation speed resulted in the change of the macrostructure of friction-stir-spot-welded zone, especially the geometry of welding interface. The results of the tensile shear test showed that the total displacement and toughness of the welds were increased with the increase of the tool rotation speed, although the maximum tensile shear load was decreased. However, the change in the dwell time at the plunge depth of the tool did not produce the remarkable variation in the macrostructure and mechanical properties of the welds. In all cases, the average hardness in friction-stir-spot-welded zone was higher than that of the base metal zone. By the friction stir spot welding technique, the welds with the excellent mechanical properties than the mechanically-clinched joints could be obtained.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1990.11a
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• pp.63-68
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• 1990

Friction and wear behavior of a unidirectional high modulus carbon fiber reinforced epoxy composite exposed to high and low humidity was experimentally examined with various sliding speeds. The results show that the moisture at the sliding surface greatly influences friction and wear properties of the composite. It is also discoverd that the difference in friction and wear behavior between samples with different fiber orientations is mainly due to the anisotropic properties caused by the microstructure of oriented graphite crystals in the carbon fibers and the macrostructure of fiber orientation in the matrix.

• Tribology and Lubricants
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• v.6 no.2
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• pp.88-93
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• 1990

Friction and wear behavior of a unidirectional high modulus carbon fiber reinforced epoxy composite exposed to high and low humidity was experimentally examined with various sliding speeds. The results show that the moisture at the sliding surface greatly influences friction and wear properties of the composite. It is also discoverd that the difference in friction and wear behavior between samples with different fiber orientations is mainly due to the anisotropic properties caused by the microstructure of oriented graphite crystals in the carbon fibers and the macrostructure of fiber orientation in the matrix.

• Korean Journal of Materials Research
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• v.22 no.6
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• pp.309-315
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• 2012

Metal foam has many excellent properties, such as light weight, incombustibility, good thermal insulation, sound absorption, energy absorption, and environmental friendliness. It has two types of macrostructure, a closed-cell foam with sealed pores and an open-cell foam with open pores. The open-cell foam has a complex macrostructure consisting of an interconnected network. It can be exploited as a degradable biomaterial and a heat exchanger material. In this paper, open cell Mg alloy foams have been produced by infiltrating molten Mg alloy into porous pre-forms, where granules facilitate porous material. The granules have suitable strength and excellent thermal stability. They are also inexpensive and easily move out from open-cell foamed Mg-Al alloy materials. When the melt casting process used an inert gas, the molten magnesium igniting is resolved easily. The effects of the preheating temperature of the filler particle mould, negative pressure, and granule size on the fluidity of the open cell Mg alloy foam were investigated. With the increased infiltration pressure, preheat temperature and granule sizes during casting process, the molten AZ31 alloy was high fluidity. The optimum casting temperature, preheating temperature of the filler particle mould, and negative pressure were $750^{\circ}C$, $400-500^{\circ}C$, and 5000-6000 Pa, respectively, At these conditions the AZ31 alloy had good fluidity and castability with the longest infiltration length, fewer defects, and a uniform pore structure.

• Journal of Korea Foundry Society
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• v.12 no.3
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• pp.220-229
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• 1992

The degree of purification and the macrostructure of high purity aluminium were studied through the alternate stirring method in order to improve the nonuniformity of solute concentration in the unidirectional stirring method. The $2^3$ factorial design was done to examine the effects of experimental factors more qualitatively. In the relatively low stirring speed of 1500 rpm with alternate stirring mode, the uniform solute profile and refined grain structure were obtained due to strong washing effect and turbulent fluid flow. It was induced by the transition of the momentum boundary layer by alternation of the stirrer. It was concluded from this study that the alternate stirring mode was more effective to obtain the uniformity of solute even in the stirring speed of 1500 rpm. But the degree of purification decreased below the critical alternating period. When 2N(99.8wt.%) aluminium was used as the starting material the morphology of solid-liquid showed the cellular shape and the columnar grains were inclined to the direction of rotation. This inclined grain growth resulted from the difference of relative velocities of solid and liquid. The inclined angle was increased as the stirring speed increased and solidification proceeded. In the case of 4N aluminium, there was no inclined grain growth and it was confirmed from the macrostructure and SEM work that the morphology of solid-liquid interface was planar. From the factorial design, it was found that the alternate stirring mode showed poorer purification effect than that of unidirectional stirring mode at low speed(500 rpm). In addition, the factor that had the most significant effect on the degree of purification was the stirring speed.

• Clinical and Experimental Otorhinolaryngology
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• v.11 no.4
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• pp.250-258
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• 2018

Objectives. To compare narrative skills between fourth and fifth grades of Persian-speaking students with hearing impairments and typical hearing students of the same grade and also to evaluate the effects of group, sex, hearing age, and educational grade of the students on their spoken/written narrative performance. Methods. The subjects were 174 students aged 10-13 years, 54 of whom wore cochlear implants, 60 suffered from moderate to severe hearing losses and wore hearing aids, with the remaining 60 students being typical hearing in terms of the sense of hearing. The micro- and macrostructure components of spoken and written narrative were elicited from a pictorial story (The Playful Little Elephant) and then scored by raters. Results. Compared to the typical hearing, the students with hearing impairments had significantly lower scores in all of the microstructure components of narratives. However, the findings showed no significant difference among different groups in macrostructure components of narratives. It was also revealed that the students had equal performance in spoken and written narrative. Finally, factor analysis manifested that group, sex, hearing age, and educational level of children might alter the outcome measures in various interactions. Conclusion. Although cochlear implantation was more effective than hearing aid on spoken and written narrative skills, the Persian-speaking students with hearing impairments were seen to need additional trainings on microstructure components of spoken/written narrative.