• Journal of the Korean Crystal Growth and Crystal Technology
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• v.16 no.1
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• pp.8-11
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• 2006

The magnetic properties and crystal structures of $Sm_yGd_{2-y}Fe_{17-x}Si_x$ alloys ($0\leq\;x\leq2\;and\;y=0\~1.67$) have been investigated using x-ray diffraction and magnetic measurements. The $Sm_yGd_{2-y}Fe_{17-x}Si_x$ specimens were crystallized to the rhombohedral $Th_2Zn_{17}-structure$ with less than $5mol\%$ of impurities. The unit cells of the mixed rare-earth samples are smaller than those of $Sm_2Fe_{17}\;and\;Gd_2Fe_{17}.$ For example, the $T_c\;of\;SmGdFe_{17}\;(255^{\circ}C)$ is approximately 160 and $800^{\circ}C)$ higher than that of $Sm_2Fe_{17}\;and\;Gd_2Fe_{17},$ respectively. The $T_cs$ measured for $Sm_yGd_{2-y}Fe_{17-x}Si_x$ samples, 280 to $290^{\circ}C)$, are among the highest values observed for a $R_2Fe_{17-x}M_x$ intermetallic where M is a substituent other than cobalt.

• Bulletin of the Korean Mathematical Society
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• v.57 no.3
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• pp.691-707
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• 2020

In this paper, we introduce and study the notions of weakly ⊕-supplemented modules, weakly D2 modules and weakly D2-covers. A right R-module M is called weakly ⊕-supplemented if every non-small submodule of M has a supplement that is not essential in M, and module M_R is called weakly D2 if it satisfies the condition: for every s ∈ S and s ≠ 0, if there exists n ∈ ℕ such that sⁿ ≠ 0 and Im(sⁿ) is a direct summand of M, then Ker(sⁿ) is a direct summand of M. The class of weakly ⊕-supplemented-modules and weakly D2 modules contains ⊕-supplemented modules and D2 modules, respectively, and they are equivalent in case M is uniform, and projective, respectively.

• Journal of the Korean Data and Information Science Society
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• v.10 no.2
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• pp.501-510
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• 1999

We have seen a rapid development of multimedia intustry as computer evolves and the internet has changed our way of life dramatically in these days. There we several attempts to teach elementary statistics on the web but most of them are based on commercial products. The need for statistical data analysis and decision making based on those analysis is growing. In this article we try to show one way of reaching that goal by using a server side scripting language PHP3 toghether with extra graphical module and statistical distribution module on the web. We showed some elementary exploratory graphical data analysis and statistical inferences. There are plenty of room of improvements to make it a full blown statistical analysis tool on the web in the new future. All the programs and databases used in our article we public programs. The main engine PHP3 is included as an apache web server module so it is very light and fast. It will be much better when the PHP4(ZEND) will be officially out in terms of processing speed.

• Convergence Security Journal
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• v.6 no.3
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• pp.79-86
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• 2006

This paper studies the sensitivity analysis of an infrared rays (IR) sensor (SHARP-GD2D12) with bluetooth communication. To evaluate the performance of the IR sensor-bluetooth module, the distance and angle data between the sensor and the fixed object are measured with an IR sensor and the measured data are transferred to PC via bluetooth within 100 meters. This experiment shows that the IR sensor-bluetooth system can be used to measure the distance and angle for a fixed object within 100 meters.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.6
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• pp.469-477
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• 2008

Purpose: The goal of this paper is to present the design and performance of a position encoding circuit for $16{\times}16$ array of position sensitive multi-anode photomultiplier tube for small animal PET scanners. This circuit which reduces the number of readout channels from 256 to 4 channels is based on a charge division method utilizing a resistor array. Materials and Methods: The position encoding circuit was simulated with PSpice before fabrication. The position encoding circuit reads out the signals from H9500 flat panel PMTs (Hamamatsu Photonics K.K., Japan) on which $1.5{\times}1.5{\times}7.0\;mm^3$ $L_{0.9}GSO$ ($Lu_{1.8}Gd_{0.2}SiO_{5}:Ce$) crystals were mounted. For coincidence detection, two different PET modules were used. One PET module consisted of a $29{\times}29\;L_{0.9}GSO$ crystal layer, and the other PET module two $28{\times}28$ and $29{\times}29\;L_{0.9}GSO$ crystal layers which have relative offsets by half a crystal pitch in x- and y-directions. The crystal mapping algorithm was also developed to identify crystals. Results: Each crystal was clearly visible in flood images. The crystal identification capability was enhanced further by changing the values of resistors near the edge of the resistor array. Energy resolutions of individual crystal were about 11.6%(SD 1.6). The flood images were segmented well with the proposed crystal mapping algorithm. Conclusion: The position encoding circuit resulted in a clear separation of crystals and sufficient energy resolutions with H9500 flat-panel PMT and $L_{0.9}GSO$ crystals. This circuit is good enough for use in small animal PET scanners.