• Advanced Composite Materials
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• 제16권1호
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• pp.31-44
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• 2007

The purpose of this study is to improve the examining and understanding of the bonding behavior of Fiber Reinforced Polymer (FRP) sheets bonded to concrete blocks and steel plates under fatigue loading. First, a series of experimental investigations is summarized in the paper. The fatigue behavior of bonding surface between FRP sheets and concrete is finally characterized by the conducted P-S-N diagram representing the relationship among the probability of FRP debonding (P), the bond stress amplitudes (S), and the number of cycles (N) at debonding on a semi-logarithmic scale. The different debonding modes for various fracturing surface are also investigated and evaluated.

• Progress in Superconductivity
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• 제3권2호
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• pp.159-162
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• 2002

We have detected cracks inside multi-layer metal sheets with nondestructive evaluation system consisting of SQUID gradiometer. Double D-shape coil was carefully designed with computer simulation for spatial distribution of magnetic field. It was aligned and placed in between SQUID and metal sheets in order to reduce the field effect to SQUID and to maximize eddy current in the sheets. The metal plate in bottom of the metal stack contained artificial cracks which were scanned by an X-Y scanning system. The information of crack position and size could be estimated by analysis of SQUID signal. Details of the results will be discussed .

• Journal of information and communication convergence engineering
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• 제2권2호
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• pp.97-101
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• 2004

This paper is about the use of existing evaluation methods, which evaluate learning determined by the score of an exam, which is either a multiple-choice type or single choice type question. These scores don't show the objective evaluations that cause some negative opinions about the scores. In this paper, we propose that the evaluation of the methods of self-directed learning use the triangle-type function of the fuzzy theory so that the learner can objectively evaluate their own learning ability. The proposed method classifies the result of learning into three fuzzy grades to calculate membership, and evaluate the result of an exam according to the final fuzzy grade degree as applied to the fuzzy grade sheets.

• Journal of Periodontal and Implant Science
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• 제47권6호
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• pp.402-415
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• 2017

Purpose: The aim of this study was to determine the effects of patterned human periodontal ligament stem cell (hPDLSC) sheets fabricated using a thermoresponsive substratum. Methods: In this study, we fabricated patterned hPDLSC sheets using nanotopographical cues to modulate the alignment of the cell sheet. Results: The hPDLSCs showed rapid monolayer formation on various surface pattern widths. Compared to cell sheets grown on flat surfaces, there were no significant differences in cell attachment and growth on the nanopatterned substratum. However, the patterned hPDLSC sheets showed higher periodontal ligamentogenesis-related gene expression in early stages than the unpatterned cell sheets. Conclusions: This experiment confirmed that patterned cell sheets provide flexibility in designing hPDLSC sheets, and that these stem cell sheets may be candidates for application in periodontal regenerative therapy.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1994년도 박판성형기술의 진보
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• pp.99-118
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• 1994

In recent years reduction in noise and vibration in automobile has been strongly required not only from the standpoint of environmental regulations but also for raising the commercial value and ride comfort. Vibration damping steel sheets, which are composites made by sandwitching a visco-elastic resin layer between two steel sheets, have been developed as effective noise-abating materials and have found a growth of use in automobile industries. Vibration damping steel sheets for commercial use must be excellent in vibration damping property, press formability and spot weldability, but are inferior to ordinary steel sheets. In this study, the mechanical properties of vibration damping steel are evaluated, and press formability is analysed on the basis of those properties and shear bonding strength. The development of engine oil pan using damping steel sheets are also reported, focusing on serious problems in oil pan drawing.

• 한국표면공학회지
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• 제39권5호
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• pp.210-214
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• 2006

In order to enhance the electromagnetic shielding efficiency of commercialized cold-rolled steel sheets, we have prepared Ni deposited steel sheets by the electrodeposition method. Surface alloying with Ni and Fe was achieved on a steel sheet by diffusion annealing process. Shielding effectiveness measurement results showed that annealed Ni electrodeposited steel sheets enhanced the shielding efficiency up to about 3 dB in the frequency range of 20 to 200Hz, compared with that of non-deposited steel sheets.

• Journal of the Korean Wood Science and Technology
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• 제26권1호
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• pp.87-96
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• 1998

The bending performances were evaluated at the radiata pine plywood through veneer compositions encompassing veneer quality, ply-numbers and overlays of the high density- or medium density-phenol resin impregnated sheets (hereafter abbreviated as resin sheets) on the raw plywood. In addition, a prediction on the bending MOE of veneers and plywoods was carried out by the nondestructive testing with stresswave timer. The summarized results were as follows: I. Bending strength and bending MOE of resin sheets-overlaid plywoods in parallel surface grain direction through 5 and 7ply were increased by 13 to 45% and 17 to 34%, respectively. Resin sheets-overlay occurred an increasing effect of the strength efficiency i.e. strength perpendicular-to-grain direction versus that parallel-to-grain direction, showing the phenomenon that the plywood strength becomes greater at the perpendicular-to-grain direction of 7ply than at that of 5ply. Displacement at bending failure had a greater trend at 7ply than at 5ply, and was decreased by resin sheets-overlay. 2. After the nondestructive bending MOEs were measured for individual veneers, these veneers were rearranged in plywood-manufacture. In these plywoods, including resin sheets-overlay, the actual MOE was predictable with feasibility of $R^2$=0.53, and also the nondestructively-evaluated MOE was lower by 20% in raw plywood, and higher 20% in LVL than actual bending MOEs.

• 한국의료질향상학회지
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• 제9권2호
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• pp.176-197
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• 2002

Backgound : This study is to suggest the standardized format of the clinical sheets and the standardized items of every clinical sheet. The standardization of the medical records will increase the faithfullnes of the contents in them and it will contribute to construct the good health information system. Method : From Jan. 1st. 2001 to March 31st 2001, we gathered as many paper clinical sheets as possible by every class of institutions to review the faithfulness of the clinical contents in them. Clinical sheets of 9 tertiary care hospitals, 6 general hospitals and 56 clinics were gathered. Two experienced medical record administrators reviewed them. The review focus was to check whether the items recommend by the hospital standardization review criteria and hospital service evaluation organization were appeared in the clinical sheets and whether the contents of every item were written. Results : Tertiary care hospitals; In case of administrative data, the contents were filled well if the items were fixed. The clinical data like C.C, history,physical examiniation were filled well, but if the items were not fixed, some items were omitted. The result is that more items are to be filled if they are fixed. General hospitals Administrative data were filled more than 50%. Final diagnosis was filled about 66.7%.But other clinical data were not filled well and not many clinical related items were appeared in the sheets.In the legal point of view, the reason for visiting hosptals or the right diagnosis, patient condition at discharge could not be confirmed well.In surgery cases, surgical procedures could not be confirmed well as many surgical related information(surgery time, fluids and blood, number of sponges, biopsy, etc) were omitted. Clinics More than 70% administrative data were filled and fixed as items. Among the clinical related data, laboratory result was the most credible data. But without the right diagnosis, drug orders were given and doctors' written signatures were not appeared over 96.4%. So the clinical sheets cannot be used as a legal document. Conculusion : There was a tendency that the contents were filled well if the items were fixed in the documents, We also suggest a clinical check list to review the completeness and faithfulness of the clinical sheets. If many hospitals use the suggested clincal check list and if they make the necessary items fixed in the clinical sheets, the quality of the medical record will increase dramatically.

• 한국초등과학교육학회지:초등과학교육
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• 제21권1호
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• pp.111-125
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• 2002

The aim of this study is to make it sure how pupils' science inquiry skills and attitude are influenced when they are taught by using the work-sheets for the differentiated learning according to their ability. In order to accomplish this aim, two classes of the fourth grade in the elementary school were distinguished into two groups: one was the experimental class and the other, the comparative class. The experimental class was given 52 hours of science lessons using the above sheets, and the comparative class, the general method of teaching. In order to compare their scientific interest and learning ability of the two groups each other, pupils were tested the standardized achievement in advance. The two groups were also given "ex post facto test" to measure the variation of their inquiry skills and attitude after the lessons. In addition, the experimental class was tested to measure their learning attitude after they are teamed the science with the sheets. The results of this study are as follows: 1. According to the percentile statistics of the science inquiry skills test between the two groups, the work-sheets for the differentiated teaming helped pupils develope their inquiry skills remarkably. 2. The work-sheets did not lead to significant difference between the learning ability of boys and girls. 3. The science lesson using the work-sheets showed positive influences in increasing pupils' scientific attitude. 4. About 77.2 percent of pupils accepted the excellent records of the evaluation in the science lesson using the sheets. It can be, therefore, concluded that the science lesson using the work-sheets for differentiated teaming is one of effective science lessons to increasing pupils' science inquiry skills, compared with the general teaching method.

• 소성∙가공
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• 제16권8호
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• pp.603-613
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• 2007

This paper is concerned with joining of thin metal sheets by single stroke clinching process. This method has been used in sheet metal work as it is a simple process and offers the possibility of joining similar-dissimilar thin sheet metals. Clinching generates a joint by overlapping metal sheets deforming plastically by punching and squeezing sequence. AA 5754 aluminum alloy of 0.5 mm thick sheets have been selected as a modal material and the process has been simulated under different process conditions and the results have been analyzed in terms of the quality of clinch joints which are influenced mainly by tool geometries. The rigid-plastic finite element method is applied to analyses in this paper. Analysis is focused mainly on investigation of deformation and material flow patterns influenced by major geometrical parameters such as die diameter, die depth, groove width, and groove corner radius, respectively. To evaluate the quality of clinch joints, four controlling or evaluation parameters have been chosen and they are bottom, neck thickness of bottom and top sheets, and undercut thickness, respectively. It has been concluded from the simulation results that the die geometries such as die depth and diameters are the most decisive process parameters influencing on the quality of clinch joints, and the bottom thickness is the most important evaluation parameter to determine if the quality of clinch joints satisfies the demand for industrial application.