• The Journal of Korean Society for Radiation Therapy
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• v.11 no.1
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• pp.6-10
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• 1999

The field size can be beam output, therefore MonitorUnit can be varied due to field size dependence The purpose of this study is to evaluate and compare the dose variation according to exchange of collimator The measurements were perfomed with Wellhofer dosimetry system(water phantom. ion chamber. electrometer. system controller. build up cap. etc)and two types of linear accerlerator (Mevatron KD, MevatronMX) Scatter can be affected to field size dependence and scatter correction is separated into collimator and phantom components, scatter components can affect by exchanging of collimator Measurements of collimator scatter factor(Sc) was done in air with build up cap. 1)Square field (5cm2 to 40cm2) was measured 2)and then keeping the upper jaw constant at loom and varing lower jaw from 5cm to 40cm, 3)keeping the lower jaw constant at 10cm and varing upper jaw from 5cm to 40cm Measurements of total scatter factor(Scp) was done in water at Dmax as the procedure of collimator scatter factor measurements in water Dmax The total scatter factors were obtained to the following equation(Sp=Scp/Sc) The measured data is normalized to the data of reference field size($10{\times}10$), rectangular field is inverted to equivalent field to compare three field size data As the collimator setting is varied, the output was changed In conclusion, the error was obtained small but it must be eliminated if we intend to reach the common stated goal of $5\%$ overall uncertainty in dose determination

• Journal of the Korean Physical Society
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• v.73 no.10
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• pp.1495-1501
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• 2018

We have developed an extended three-dimensional free-electron laser (3D FEL) code with source-dependent expansion to calculate the intensity of the radiation field and the spot size in a free-electron laser oscillator. The effect of the wiggler field errors was evaluated for the case of a planar wiggler generated by a magnet stack with parabolic shaped pole faces by using the extended three-dimensional equations in a free-electron laser oscillator based on the proposed FEL facility which is to be operated in the far-infrared and the infrared regions. The radiation spot size due to the wiggler field errors also have been analyzed for wiggler errors of ${\Delta}B/B=0.0$, 0.03, 0.06 and 0.09% at z = 1 m and z = 2 m. The effect of the diffraction of radiation field due to the wiggler field errors of ${\Delta}B/B=0.0$ and ${\Delta}B/B=0.09%$ at 200 passes was evaluated by using the extended 3D code that we developed. The variation of the curvature of the phase front and the effect of the radiation field intensity due to the wiggler field errors were also evaluated for B = 0.5 T and B = 0.7 T with the wiggler error of ${\Delta}B/B=0.09%$ at 200 passes and the results were compared to those of without errors. The intensity of the radiation, behavior of the radiation spot size and the variation of the curvature of the phase were highly sensitive to the wiggler error of ${\Delta}B/B$ > 0.09%, but were less sensitive to the wiggler errors for ${\Delta}B/B$ < 0.09% in a free-electron laser (FEL) oscillator based on the proposed FEL facility.

• Journal of Ecology and Environment
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• v.43 no.2
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• pp.263-270
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• 2019

Background: The gelada baboon, Theropithecus gelada Ruppell, 1835, is an endemic primate of the central and western highlands of Ethiopia occurring between altitudes of 1800-4400 m. Variability in activity time budget between the two gelada social units, i.e., one-male units (OMUs) and all-male units (AMUs), has not been studied previously. Thus, the present study was an effort to understand intra- and inter-variations in group size and daily activity time budget in gelada baboon OMUs and AMUs at Guassa Community Conservation Area, Central Ethiopia. The instantaneous sampling method was used in the data collection. Results: Both OMU and AMU groups allocated more time for feeding (OMUs = 36.96%; AMUs = 35%) followed by moving (OMU = 25.8%; AMUs = 27%). Grooming was the most frequent social activity in both family groups (OMUs = 8.56%; AMUs = 11.81%). OMUs and AMUs did not show significant variation between themselves in the time budget and temporal distribution of their daily activities. However, the overall variation in the time budget allocated for daily activities within OMUs and AMUs was statistically significant (p < 0.05%). The different age and sex groups in OMUs (i.e., immature, sub-adult females, subordinate males, adult females, and alpha males) showed statistically significant variation in their time budget allocation for the daily activities (p < 0.05) except for feeding and moving. Alpha males had the highest proportion of resting (32.14%) and aggression (31.92%). Immature individuals were responsible for > 90% of the time budget recorded for playing while adult females showed the highest frequency of grooming. Group size of OMUs ranged between 5 and 15 individuals (mean ± SD = 11.25 ± 1.95). Adult females comprised the highest number within OMUs (mean = 4.5) followed by immature individuals (mean = 3). The group size of AMUs ranged from 4 to 8 (mean ± SD = 6.6 ± 1.5). Conclusion: Our results showed that the gelada baboon spent less time on foraging compared to previous studies at the Simien Mountains and Debre-Libanos area. We suggested this variation could be explained based on higher forage quality at Guassa Community Conservation Area resulting from better conservation of the habitat.

• Journal of Marine Life Science
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• v.4 no.2
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• pp.53-62
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• 2019

Heterotrophic bacteria are a major member of the microbial loop in the marine ecosystem and play an important role in the biogeochemical cycle decomposing organic matter. Therefore study of bacterial variation is important to understand the material cycle and energy flow of marine ecosystems. We investigated the monthly variations of bacteria and environmental factors in the Youngsan River estuary, and the correlation between bacteria and phytoplankton biomass (chlorophyll-a) including size-structure. As a result, bacteria of the Youngsan River estuary were higher in the surface than in the bottom layer, and higher in the summer than in winter. And the closer to the dike, the abundance increased, and it increased to the peaks in August, September, and June 2019 at the station closest to the dike. The chlorophyll-a also increases at the stations and time when the bacterial abundance was high and they correlates positively displaying no difference between size fractions. The results indicate that organic matter derived from phytoplankton has an effect on bacterial variation but no size-dependent effects. In addition, the seasonal pattern of bacteria increasing in proportion to the water temperature suggests the effect of water temperature on the growth of bacteria. No association of bacterial abundance variation with nutrient supply due to freshwater input was observed. In this study, dissolved oxygen was depleted and hypoxia was observed for a short time when a strong stratification was not developed. This may be resulted from the supply of organic matter from phytoplankton and the consumption of oxygen due to bacterial decomposition.

• Korean journal of applied entomology
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• v.37 no.1
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• pp.23-30
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• 1998

Restriction fragment length polymorphism (RFLP) of a DNA has been a useful tool for analyzing genetic variation. This research was performed to establish an RFLP analytic method on the mitochondrial DNA (mtDNA) of the beet armyworm, Spodoptera exigua (Hiibner). To do this, total size of the mtDNA was measured and polymerase chain reaction (PCR) primers were selected. Its mitochondrial genome size was ca. 16kb. From a serial PCR test of 29 primers refered to the compilation of Simon et al. (1994), 22 primers were selected to amplify its mtDNA fragments. These primers resulted in short (300-700 bp) or long (1000-2000 bp) DNA products which represented a total or partial sequence of each of CO-I, CO-11, Cyt-B, ND-1, 12s rRNA, 16s rRNA, and some tRNAs. PCR-RFLP was performed in some variable mtDNA regions with 8 kinds of 4bp recognizing restriction enzymes. Different populations from Andong, Kyungsan, and Sunchun did not show any restriction site polymorphisms but had some length variation in certain regions of mtDNA.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.11 no.1
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• pp.21-31
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• 1985

The effect of dispersed phase on the stability of emulsion system with polyoxyethylene dodecyl ethers and their variation of ethylene oxide moles was studied by such methods as interfacial tension measurement, centrifugation and droplet size variation with time. The experiments showed that, in interfacial tension measurement, long chain alkanols into dispersed phaes are more effectively adsorbed onto interface, while long chain alkanes nearly not, and in centrifugation, dispersed phase with alkanols is less separated than that with alkanes. On the other hand, alkanes help more stabilyzing emulsion than alkanols in droplet size variation. And the addition of NaCl or Urea, and variation of E.O. moles have very slight effects on the stability with alkanes than with alkanols. Moreover, the longer carbon chain length is, dispersed phase is more effective on emulsion stability. Supposed from these facts is that more stable emulsion can be made with alkanes which retard molecular diffusion by water solubility decrease rather than alkanols which raise resistance to coalescence by rigid interfacial mixed monolayers formation. In conclusion, the stabilities of these emulsions are proved to be more influenced by molecular diffusion than coalescence.

• Plant Resources
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• v.3 no.3
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• pp.184-193
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• 2000

Soybean [Glycine max (L.) Merr.] seed weight is a important trait in cultivar development. Objective of this study was to identify and confirm quantitative trait loci (QTLs) for seed weight variation in the F2 and F2:3 generations. QTLs for seed weight were identified in F2 and F2:3 generations using interval mapping (MapMaker/QTL) and single-factor analysis of variance (ANOVA). In the F2 plant generation (i.e., F3 seed), three markers, OPL9a, OPM7a, and OPAC12 were significantly (P<0.01) associated with seed weight QTLs. In the F2:3 plant row generation (i.e., F4 seed), five markers, OPA9a, OPG19, OPL9b, OPP11, and Sat_085 were significantly (P<0.01) associated with seed weight QTLs. Two markers, OPL9a and OPL9b were significantly (P<0.05) associated with seed weight QTLs in both generations. Two QTLs on USDA soybean linkage group C1 and R were identified in both F2 and F2:3 generations using interval mapping. The linkage group C1 QTL explained 16% of the variation in seed weight in both generations, and the linkage group R QTL explained 39% and 41% of the variation for F2 and F2:3 generation, respectively. The linkage group C2 QTL identified in F2:3 generation explained 14.9% of variation. Linkage groups C1, C2 and R had previously been identified as harbouring seed size QTLs. The consistency of QTLs across generations and populations indicates that marker-assisted selection is possible in a soybean breeding program.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.12
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• pp.2963-2971
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• 2000

In order to obtain more realistic fracture resistance curve, research is currently underway to introduce new parameter and to quantify the constraint effect. The objective of this study is to investigate the relationship between the constraint effect of a size(plane size and thickness) and the fracture resistance curve. In this paper fracture toughness tests were performed with various plane size and various thickness of specimens in two materials. The test results showed that the effects of plane size in th4 J-R curve were significant and the curve was risen with an increase in plane size. However, relatively weak influence was observed form the change of the specimen thickness and size. The stress fields near the crack tip of th specimen is close to the HRR field according to increasing the plane size and Q stress appears different value according to material properties and the plane size.

• Journal of Welding and Joining
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• v.24 no.1
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• pp.77-87
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• 2006

Considering ferrite grain size in the base metal, the prediction model for $A_{c3}$ temperature and prior austenite grain size at just above $A_{c3}$ temperature was proposed. In order to predict $A_{c3}$ temperature, the Avrami equation was modified with the variation of ferrite grain size, and its kinetic parameters were measured from non-isothermal data during continuous heating. From calculation using a proposed model, $A_{c3}$ temperatures increased with increasing ferrite grain size and heating rate. Meanwhile, by converting the phase transformation kinetic model that predicts the ferrite grain size from austenite grain size during cooling, a prediction model for prior austenite grain size at just above the $A_{c3}$ temperature during heating was developed.

• Wind and Structures
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• v.36 no.1
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• pp.41-60
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• 2023

The effect of cladding panel size on the size reduction factor (SRF) of extreme area-averaging wind pressure (EAWP) on the facades of a high-rise building is often ignored in previous studies. Based on wind tunnel tests, this study investigated the horizontal and vertical correlations of wind pressure on the facade claddings of square-section high-rise buildings. Then, the influencing parameters on the SRF of the EAWP on the cladding panels were analyzed, which were the panel area, panel width, panel length and building width. The results show clear regional distinctions in the correlation of wind pressures on the building facades and the rules of the horizontal and vertical correlations are remarkably different, which causes the cladding size ratio to impact the SRF significantly. Therefore, this study suggests the use of the non-dimensional comprehensive size parameter b^𝜶h^1-𝜶/B (𝜶 is the fitting parameter) determined by the cladding panel horizontal size b, cladding panel vertical size h and the building width B rather than the cladding panel area to describe the variation of the EAWP. Finally, some empirical formula for the SRF of the EAWP on the cladding of a high-rise building is proposed with the nondimensional comprehensive size parameter.