• Journal of Korean Neurosurgical Society
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• v.45 no.2
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• pp.85-89
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• 2009

Objective : The International Study of Unruptured Intracranial Aneurysms (ISUIA) reported that the 5-year cumulative rupture rate of small unruptured aneurysms less than 7 mm in diameter is very low depending on the aneurysm's location. However, we have seen a large number of ruptured aneurysms less than 7 mm in clinical practice. The purpose of this study was to review our experience and to measure the size and location at which aneurysms ruptured in our patient population. Methods : We reviewed the characteristics of aneurysms, such as size and location, from the original angiograms of patients who were admitted to our hospital between January 2004 and December 2007. All aneurysms were treated surgically or through endovascular procedures. Results : Interventional or surgical treatment was given to a total of 889 patients, including 568 females and 321 males. At the time of our study, 627 cases were ruptured aneurysms and 262 cases were unruptured aneurysms. Of the ruptured cases, the mean diameter of the aneurysm was 6.28 mm. We found that 71.8% of ruptured aneurysms were smaller than 7 mm in diameter, and 87.9%, were smaller than 10 mm. Based on location, the data show that anterior communicating artery aneurysms most often presented with rupture sizes less than 7 mm (76.8%) and 10 mm (92.1%) in diameter. Most ruptured aneurysms were less than 7 mm in size, although recent studies have noted that small aneurysms are less likely to rupture. Conclusion : Although the natural history of unruptured intracranial aneurysms remains controversial, the aneurysm size and location play a signigicant role in determining the risk of rupture. Larger sample sizes and a long term study are needed to reveal the natural history and the rupture risk of unruptured intracranial aneurysms because the size of most ruptured aneurysms was less than 7 mm in diameter in our series.

• Journal of the Korean Society of Costume
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• v.49
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• pp.25-48
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• 1999

The purpose of this study is to offer fundamental data for classification of somatotype for boys of elementary school age. The subject were 458 elementary school boys aged from 7 to 12 living in Pusan, Data were collected by 57 anthropometric and 11 photographic measurements and analyzed by factor analysis according to SAS package 1. Through the factor analysis by each period of school ages 6-7 factor were obtained in upper half and they are as followings: 1) Factor 1 is horizontal size of upper half in every period 2) Factor 2 is vertical size of upper half in every period 3) Factor 3 is shoulder shape in the first period and length of upper half in the middle and latter period 4) Facto 4 sis length of upper half in the first period and shoulder shape in the middle and latter period 5) Factor 5 is angle shape of the breast and back in the first period angle shape of the lower breast and back in the middle of period and angle shape of the upper breast and back in the latter of period 6) Factor 6 is angle of shoulder in the first period angle shape of the upper breast and back in the middle of period and angle shape of the lower breast and back in the latter of period 7)Factor 7 is angle of shoulder in the latter of period 2. Through the factor analysis by each period of school ages 5-6 factor were obtained in lower half and they are as followings: 1) factor 1 is horizontal size of upper half in every period 2) Factor 2 is vertical size of upper half in every period 3) Pactor 3 is angle shape of the belly and upper buttock in the first period and length of lower half in the middle and latter period 5) Factor 5 is angle shape of the lower buttock in the first period angle shape of the upper belly and buttock in the middle of period and angle of the side posture in the latter of period 6) Factor 6 is angle shape of the lower buttock in the middle of period and angle shape of the lower belly and buttock

• Journal of the Korean School Mathematics Society
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• v.24 no.1
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• pp.39-57
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• 2021

In this study, mathematical analysis is conducted by focusing to the 'size' of the 'point' and the 'line'. The textbook descriptions of the 'point' and the 'line' in the geometry content area of middle school mathematics 1 by the 2015 revised Korean mathematics curriculum and US geometry textbooks were compared and analyzed between. First, as a result of mathematical analysis of' 'the size of a point and a segment', it was found that the mathematical perspectives could be different according to 1) the size of a point is based on the recognition and exclusion of 'infinitesimal', and 2) the size of the segment is based on the 'measure theory' and 'set theory'. Second, as a result of analyzing textbook descriptions of the 'point' and the 'line', 1) in the geometry content area of middle school mathematics 1 by the 2015 revised Korean mathematics curriculum, after presenting a learning activity that draws a point with 'physical size' or line, it was developed in a way that describes the 'relationship' between points and lines, but 2) most of the US geometry textbooks introduce points and lines as 'undefined terms' and explicitly states that 'points have no size' and 'lines have no thickness'. Since the description of points and lines in the geometry content area of middle school mathematics 1 by the 2015 revised Korean mathematics curriculum may potentially generate mathematical intuitions that do not correspond to the perspective of Euclid geometry, this study suggest that attention is needed in the learning process about points and lines.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.26 no.1
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• pp.34-42
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• 2023

Purpose: We aimed to investigate factors that correlate with fecal calprotectin (FC) levels in children and adolescents with colorectal polyps. Methods: Pediatric patients aged <19 years who underwent colonoscopic polypectomy for a juvenile polyps (JPs) and FC tests were simultaneously conducted in a multicenter, retrospective study. Baseline demographics, colonoscopic and histological findings, and laboratory tests, including FC levels, were investigated. Correlations between the factors were investigated, and linear regression analysis revealed factors that correlated with FC levels. FC levels measured after polypectomies were investigated and the FC levels pre- and post-polypectomies were compared. Results: A total of 33 patients were included in the study. According to Pearson correlation analysis, the polyp size was the only factor that showed a statistically significant correlation with FC levels (r=0.75, p<0.001). Furthermore, according to the multivariate linear regression analysis, polyp size was the only factor that showed a statistically significant correlation with FC levels (adjusted R2=0.5718, β=73.62, p<0.001). The median FC level was 400 mg/kg (interquartile range [IQR], 141.6-1,000 mg/kg), and the median polyp size was 14 mm (IQR, 9-20 mm). Nineteen patients underwent post-polypectomy FC tests. FC levels showed a significant decrease after polypectomy from a median of 445.2 mg/kg (IQR, 225-1,000) to 26.5 mg/kg (11.5-51) (p<0.001). Conclusion: FC levels significantly correlated with polyp size in children and adolescents with JPs.

• Clinical and Experimental Pediatrics
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• v.63 no.5
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• pp.189-194
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• 2020

Background: The decision to use transannular patching (TAP) during tetralogy of Fallot (TOF) repair depends on the pulmonary valve annulus size; the z score of the pulmonary annulus is the most commonly used predictor. However, definitive results are not obtained with z scores as different z score data sets are used for different parameters. Purpose: This study aimed to identify the echocardiographic and other key factors that warranted a change in the surgical method during TOF surgery. Methods: Sixty-two patients were enrolled and divided into a pulmonary valve (PV) preservation group and a TAP group. Their medical records were reviewed. Results: The z score for PV annulus (PVA), ratio of the PVA to aortic annulus size, and ratio of PVA to descending aorta (DAO) size were significantly different between the PV preservation and TAP groups (-1.72±1.52 vs. -3.07±1.94, P=0.004; 0.62±0.12 vs. 0.50±0.14, P=0.002; and 1.32±0.32 vs. 1.07±0.36, P=0.008, respectively). For TAP repair, the PVA z score had a sensitivity of 65.4% and specificity of 73.1%, ratio of PVA to aortic annulus size had a sensitivity of 73.1% and specificity of 65.4%, and ratio of PVA to DAO size had a sensitivity of 69.2% and specificity of 57.7%. The TAP group showed more monocuspid PVs (P=0.011), while the PV preservation group showed more tricuspid PVs (P=0.027). Commissurotomy was more frequently performed in the PV preservation group than in the TAP group (P=0.001). Of patients with commissurotomy, 58% showed a PV z score<-2. Conclusion: Although various echocardiographic parameters may serve as predictors for determining surgical methods for TOF patients, the PV morphology and tissue characteristics should also be considered.

• Korean Institute of Interior Design Journal
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• v.14 no.4 s.51
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• pp.79-86
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• 2005

According to the new multi-media appeared as a result of rapid growth of the information and science technique, the school library must be changed to the integration of the teach-study media resource from the existing print media. It means that the school library has to play a role of the study center with a different media from the existing teaching material, teaching instrument, facility and opportunity. The Information education must be conducted in the way of an integrated education course and able to do both information transaction and problem settlement. The education facility to solve this problem is the school library. Therefore, the school library becomes important more and more. It means that the school library is the center of entire study and education material for the teacher and student is focused on it. It is urgent to make the standard of the school library In order to cope with the new education and information environments. And especially it is very important to make a plan about the location and scale of the school library to improve the quality of the children's studying activity. The location of the school library is decided under consideration of the relationship with other room of school house and the proper scale of it is between 2.5units and 7.0units of classroom based on the number of class.

• Journal of Periodontal and Implant Science
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• v.39 no.sup2
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• pp.253-259
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• 2009

Purpose: This study was aimed to evaluate the effect of implant drilling speed on the composition of particle size of collected bone debris. Methods: $Br{\aa}nemark$ $System^{(R)}$ drills were used to collect bone debris from 10 drilling holes (1 unit) at 1,500 rpm (Group A) and 800 rpm (Group B) in bovine mandible. After separating particles by size into > 500 ${\mu}m$, between 250 ${\mu}m$ and 500 ${\mu}m$, and < 250 ${\mu}m$ fractions, particle wet volume, dry volume, and weight were measured and the proportion of 3 fractions of bone debris to total wet volume, dry volume and weight was calculated as wet volume % , dry volume % and weight %. Results: No significant differences were found between Group A and B in wet volume, dry volume, and weight. However, of >500 ${\mu}m$ fractions, Group B had significantly higher wet volume %(P = 0.0059) and dry volume %(P = 0.0272) than in Group A. Conclusions: The drilling speed influenced the composition of particle size in collected drilling bone debris. The drilling in 800 rpm produced the more percentage of large particles than in 1,500 rpm. However, the drilling speed didn't effect on total volume of and weight of bone debris.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.3
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• pp.73-82
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• 2011

Most of countries start to restrict the emission gases of vehicles especially CO2 because of the global warming. Many vehicle companies including Toyota have launched various HEVs to satisfy the restriction laws and to improve the vehicle's efficiency. However, development for heavy-duty hybrid system is not plentiful rather than the passenger car. In this study, we choose the optimal size of engine, motor and battery for heavy-duty hybrid systems using dynamic programming. Also we analyze the correlation of the system's cost and efficiency because the added cost of vehicle to make the hybrid system is very important factor for the manufacturing companies. Finally, this study suggests a method to choose the appropriate system components size considering its performance and the cost. With this method, it is possible to select the component size for various systems.

• Nuclear Engineering and Technology
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• v.50 no.1
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• pp.132-139
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• 2018

Nanocrystalline reduced activation ferritic/martensitic (RAFM) steel samples were prepared using surface mechanical attrition treatment (SMAT). Un-SMATed and SMATed reduced activation ferritic/martensitic samples were irradiated by helium ions at $200^{\circ}C$ and $350^{\circ}C$ with 2 dpa and 8 dpa, respectively, to investigate the effects of grain boundaries (GBs) and temperature on the formation of He bubbles during irradiation. Experimental results show that He bubbles are preferentially trapped at GBs in all the irradiated samples. Bubble denuded zones are clearly observed near the GBs at $350^{\circ}C$, whereas the bubble denuded zones are not obvious in the samples irradiated at $200^{\circ}C$. The average bubble size increases and the bubble density decreases with an increasing irradiation temperature from $200^{\circ}C$ to $350^{\circ}C$. Both the average size and density of the bubbles increase with an increasing irradiation dose from 2 dpa to 8 dpa. Bubbles with smaller size and lower density were observed in the SMATed samples but not in the un-SMATed samples irradiated in the same conditions, which indicate that GBs play an important role during irradiation, and sink strength increases as grain size decreases.

• Nuclear Engineering and Technology
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• v.47 no.6
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• pp.738-745
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• 2015

The catalytic exchange of hydrogen isotopes between hydrogen and water has been known to be a very useful process for the separation of tritium from tritiated water. For the process, a highly active hydrophobic catalyst is needed. This study provides an effective fabrication method of size-controlled platinum/poly[styrene-divinylbenzene-tri(propylene glycol) diacrylate] [Pt/poly(SDB-TPGDA)] hydrophobic catalyst beads with a narrow size distribution. Platinum nanoparticles were prepared by ${\gamma}$-ray-induced reduction in the aqueous phase first, and then uniformly dispersed in SDB-TPGDA comonomer after the hydrophobization of platinum nanoparticles with alkylamine stabilizers. The porous Pt/poly(SDB-TPGDA) hydrophobic catalyst beads were synthesized by the UV-initiated polymerization of the mixture droplets prepared in a capillary-based microfluidic system. The size of as-prepared catalyst beads can be controlled in the range of $200-1,000{\mu}m$ by adjusting the flow rate of dispersed and continuous phases, as well as the viscosity of the continuous phase. Sorbitan monooleate and cyclohexanol were used as coporogens to control the porosities of the catalyst beads.