• Journal of Educational Research in Mathematics
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• v.14 no.4
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• pp.435-447
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• 2004

There are divergent opinions about condition of triangle-determining. The purpose of this study was to compare those opinions and to identify cause of this phenomena. As a result of our study, we got to find out significant characteristics of proposition related to condition of triangle-determining. These aspects shows what cause of that phenomena is. First, that proposition is used as a theortical tool, not as a practical one. Second, that proposition presupposes that a triangle exists. Third, that proposition is connected with minimality and generality. However, our analysis is for teacher, not for student. Thus, we suggest a guiding principle as well as a guiding method in relation to teaching of that proposition.

• Resources Recycling
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• v.9 no.4
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• pp.50-55
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• 2000

Recycling technology of aluminum foil scraps into aluminum flake powder by ball milling in dry or wet conditions was studied. Aluminum foil were laminated each other, elongated through microforging by the falling balls, fragmented into small foils and then changed into flake powder during ball milling. It is also possible to recycle foil scraps with thickness less than $60\mu\textrm{m}$ into aluminum paste by wet ball milling. As initial foil thickness decreases, foil is easily milled to flake powder by wet milling in mineral spirits. the appearance and the opaque character of glass painted with aluminum paste obtained by wet milling of foils are similar to those of aluminum paste made by ball milling of gas atomized powder.

• Analytical Science and Technology
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• v.21 no.4
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• pp.279-283
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• 2008

Blood soil and the mixture of blood soil, elvan soil and, silica soil materials were molded, then they were sintered in $1100^{\circ}C$ and were used for the emission of the far infrared ray boll. The emission from the manufactured bolls was relatively high in the range of $8{\sim}12{\mu}m$ wavelength each. The elution of minerals from mixture bolls was very low, but the elimination of heavy metal cadmium ion in activated water and energy water treated with mixture bolls was very high. Activated water and energy water had a high to the UV protected ability in comparison to drinking water.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.15-17
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• 2022

In order to minimize surplus parts in ball bearing selective assembly systems, it is necessary to optimize the selection probability by grasping the dimensional distribution of each part. But the use of a complex system causes delays in the production process. In this paper, we propose cluster priority selection algorithm that can quickly and simply determine the selection priority in ball bearing selective assembly system. In addition, we assume the simulated situation with the data collected in the actual ball bearing selective assembly process, and evaluate the incidence of surplus part and runtime by simulating the cluster priority selection algorithm and the exiting algorithm. As a result of the simulation, the cluster priority selection algorithm generated 83.8% less surplus parts, and 39.7% less runtime than the existing algorithm.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.10
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• pp.80-89
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• 2008

Patch antennas with an array of pins interconnecting the patch and the ground (Pin array patch antennas) are fabricated and their characteristics are measured. The radiation characteristics of pin array patch antennas are compared to those of conventional patch antennas. The suppressions of the radiation in horizontal directions in E-plane and H-plane are more than 10 dB and 4 dB, respectively. The forward radiation is increased, while the backward radiation is decreased. The directivity is improved because the half-power beamwidth of radiation patterns in both E-plane and H-plane is reduced. The resonance frequency of a pin array patch antenna increases as the pin radius of a pin amy patch antenna increases. An optimum pin radius of a pin array patch antenna exists for the maximum suppression of the radiation in horizontal directions.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.3
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• pp.463-467
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• 1998

The microstructure evolution during mechanical alloying (MA) of Nb and Sn powder; of average composition $Nb_3Sn$, has been investigated by X-ray diffraction (XRD). The structural development with milling time depends on the ball size for a given powder/ball ratio. Using a larger ball of 9.5 mm diameter, the elemental powders initially alloy mechanically to form an A15 structure phase, and then amorphized with continued milling. However, in case of milling with a smaller ball of 3.968 mm diameter, an amorphous phase is first formed. These results can be understood by considering the dependence of the milling energy on the ball size. The homogeneous stoichiometric $Nb_3Sn$ phase could be easily obtained by heat treatment of supersaturated solid solution produced by MA. Heat treatment of an amorphous formed by MA resulted in the mixture of the $Nb_3Sn$ and $Nb_6Sn_5$phases.

• KOMUNHWA
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• no.56
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• pp.29-58
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• 2000

A lot of dolmens without burial chamber have been brought to the light around Honam (southwestern provinces of Korea) area. Even though they are commonly classified as dolmens of surrounding stone type(圍石式), it seems necessary to put under the category of

• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.499-508
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• 2009

The purpose of this study was to compare and analyze flick shooting motion in penalty corner between high school players and national players in field hockey. Five high school players and six national players participated in this study. The 3D kinematic data were collected for each subject performing the penalty corner stroke. The results of the study were as follows: 1) The national players had higher stick head and ball velocity than the high school players. 2) The forward length between ball and support foot during ball catching with stick head was longer in the national players than the high school players. 3) At the Z axis of the E5 event, the center of gravity of the national players was lower than that of the high school players. 4) At the Z axis of the E5 event, left hip angle of the national players was lower than that of the high school players. 5) The national players had longer drag length of ball than the high school players. 6) The national players had higher hand and lower arm angular momentum than the high school players.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.1
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• pp.55-59
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• 1982

With naked barley varieties which are different in their spring habits, variations in seed proteins during ripening were checked by acrylamide gel electrophoresis. In case of 7% acrylamide gel among protein bands ⅰ-band was observed only in both Sedohadaka (intermediate type) and Wanju (spring type) throughout the ripening period, and j-band was detected in all the three varieties until 33 days after heading, but not in Nonsangwa (winter type) thereafter. In case of 6M urea-7% acrylamide gel z-band was traced only in Nonsangwa, contrary to i-band, throughout the ripening period. U-band was observed in all the three varieties until 23 days after heading, but not in Nonsangwa thereafter. X-band showed opposite from u-band. Throughout the ripening period Sedohadaka was significantly more similar in the electrophoretic patterns to Wanju than to Nonsangwa.

• Journal of Digital Convergence
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• v.15 no.1
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• pp.129-141
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• 2017

This study analyzed and compared the accounting earnings quality after the adoption of K-IFRS, targeting the stock exchange-listed firms (KOSPI, KOSDAQ). The analysis first revealed that KOSPI had higher quality accruals, and better persistence and predictability of the reported earnings and cash flows, compared to KOSDAQ. Second, in both KOSPI and KOSDAQ, the predictability of future cash flow showed that the accounting earnings was better than the cash flows. Third, for the persistence and predictability of earnings associated with the degree of accruals, in KOSPI and KOSDAQ both all, groups with better accruals quality had greater persistence and predictability of earnings, and a better future cash flow predictability of accounting earnings.