• Anatomy and Cell Biology
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• v.56 no.4
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• pp.456-462
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• 2023

Plate fixation has become the preferred approach for treating displaced midshaft clavicle fractures. However, plate fixation of the clavicle presents several unique challenges, including its complex bony architecture and its immediate subcutaneous location. In many cases, we have observed that precontoured implants do not conform to the clavicular anatomy, and many patients complain of postoperative implant-related discomfort. A total of 111 clavicles, both left and right sides, were examined to match two commonly used designs of anatomical pre-contoured superior anterior clavicle plates, with and without lateral extension. The anteroposterior (AP) plane congruence of the plate to the underlying bone, the vertical gap between the bone and plate, and the length of the plate that was off the bone either anteriorly and/or posteriorly at both ends of the clavicle were measured. The scoring system was used to determine the fit of the implant on the clavicle as anatomic, good, or poor. We found that the maximum superior bow of the clavicle was lateral to the midline by 30.75 mm and 30.5 mm on the right and left sides, respectively. The magnitude of the bow was 4.28 mm and 4.46 mm on the right and left sides, respectively. We also found that the plate was a poor fit in 75.86% of cases on the left side and 73.5% of cases on the right side. Manipulating the plates during surgery was very difficult in the AP plane.

• Journal of the Korean Mathematical Society
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• v.36 no.4
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• pp.747-756
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• 1999

In ring theory it is well-known that a ring R is (von Neumann) regular if and only if all right R-modules are flat. But the analogous statement for this result does not hold for a monoid S. Hence, in sense of S-acts, Liu (]10]) showed that, as a weak analogue of this result, a monoid S is regular if and only if all left S-acts satisfying condition (E) ([6]) are flat. Moreover, Bulmann-Fleming ([6]) showed that x is a regular element of a monoid S iff the cyclic right S-act S/p(x, x2) is flat. In this paper, we show that the analogue of this result can be held for automata and them characterize regular semigroups by flat automata.

• Progress in Medical Physics
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• v.9 no.3
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• pp.127-136
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• 1998

On-line geometrical quality assurance system has been developed using electronic portal imaging system(OQuE). EPID system is networked into Pentium PC in order to transmit the acquisited images to analysis PC. Geometrical QA parameters, including light-radiation field congruence, collimator rotation axis, and gantry rotation axis can be easily analyzed with the help of graphic user interface(GUI) software. Equipped with the EPID (Portal Vision, Varian, USA), geometrical quality assurance of a linear accelerator (CL/2100/CD, Varian, USA), which is networked into OQuE, was performed to evaluate this system. Light-radiation field congruence tests by center of gravity analysis shows 0.2～0.3mm differences for various field sizes. Collimator (or Gantry) rotation axis for various angles could be obtained by superposing 4 shots of angles. The radius of collimator rotation axis is measured to 0.2mm for upper jaw collimator, and 0.1mm for lower jaw. Acquisited images for various gantry angles were rotated according to the gantry angle and actual center of image point obtained from collimator axis test. The rotated images are superpositioned and analyzed as the same method as collimator rotation axis. The radius of gantry rotation axis is calculated 0.3mm for anterior/posterior direction (gantry 0$^{\circ}$ and 170$^{\circ}$) and 0.7mm for right/left direction(gantry 90$^{\circ}$ and 260$^{\circ}$). Image acquisition for data analysis is faster than conventional method and the results turn out to be excellent for the development goal and accurate within a milimeter range. The OQuE system is proven to be a good tool for the geometrical quality assurance of linear accelerator using EPID.