• Structural Engineering and Mechanics
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• v.53 no.1
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• pp.105-130
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• 2015

In this paper, the classical continuum mechanics is adopted and modified to be consistent with the unique behavior of micro/nano solids. At first, some kinematical principles are discussed to illustrate the effect of the discrete nature of the microstructure of micro/nano solids. The fundamental equations and relations of the modified couple stress theory are derived to illustrate the microstructural effects on nanostructures. Moreover, the effect of the material surface energy is incorporated into the modified continuum theory. Due to the reduced coordination of the surface atoms a residual stress field, namely surface pretension, is generated in the bulk structure of the continuum. The essential kinematical and kinetically relations of nano-continuums are derived and discussed. These essential relations are used to derive a size-dependent model for Mindlin functionally graded (FG) nano-plates. An analytical solution is derived to show the feasibility of the proposed size-dependent model. A parametric study is provided to express the effect of surface parameters and the effect of the microstructure couple stress on the bending behavior of a simply supported FG nano plate.

• The Korean Journal of Applied Statistics
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• v.32 no.4
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• pp.643-652
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• 2019

We propose a method for sample size determination using design effect formulas when a sample is resigned for a repeated survey. The proposed method enables the determination of the sample size by incorporating the impact of various design components to the sampling error through design effect formulas that are applicable under multistage sampling design and stratified multistage sampling designs.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.3
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• pp.341-350
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• 2021

This study tested the effect of the board of directors' (BOD) characteristics on the corporate performance of the Jordanian industrial and service companies listed on the Amman Stock Exchange (ASE) during the period 2015-2019. The characteristics of the BOD were measured through the following variables: MO = managerial ownership; CEODU = CEO duality; BI = board independence; GD = gender diversity; ND = nationality diversity; AE = advanced education; BM = board meetings; BSIZ = board size; CSIZ = corporate size; CA = corporate age. The corporate performance was measured by return on assets (ROA) and return on equity (ROE). The corporate size and corporate age were used as control variables. The study sample consisted of 85 industrial and service companies with 425 observations to identify the nature of the effect of the BOD characteristics on performance. This study applied time-series data (panel data), and the multiple linear regression method was used to achieve study objectives. Results showed a positive effect of the study variables on performance, while the corporate age and the education level (BOD members) have a negative effect on performance.

• Journal of the Korean Society of Clothing and Textiles
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• v.35 no.5
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• pp.575-586
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• 2011

This study first examines the effect of perceived body characteristics, satisfaction with body characteristics on perceived size related risk, and internet shopping clothing behaviors; in addition, it also examines the effect of the perceived size related risk on clothing behaviors. A questionnaire was conducted with responses from 219 female students, aged 19 to 25. Data was analyzed by frequency analysis, correlation analysis, ANOVA and Duncan test. The findings suggest that a consumer satisfied with body characteristics has active clothing behaviors to improve her appearance or body image. The effects of perceived body characteristics and satisfaction with body characteristics on perceived size related risk are also identified. The perceived size related risk increases when the size information of an internet shopping mall is insufficient compared to the situation when the consumer is not satisfied with her body characteristics. The meaningful differences of clothing behaviors according to extent of perceived size related risk are identified.

• Korean journal of food and cookery science
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• v.23 no.3 s.99
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• pp.314-320
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• 2007

The objective of this study was to investigate the effect of grain size on the physicochemical properties of rice porridge. Here, the grain size of the rice was classified as whole grain, half grain, and flour by traditional Korean cooking methods. The viscosity of the rice flour porridge was highest for the among the three different grain size porridges. In the amylographs, the increase in viscosity for the whole grain porridge was higher than that of the rice flour porridge during cooling. The soluble solid and reducing sugar contents of the rice porridges increased according to the rice grain size, while the blue value decreased. The SDI (starch digestion index) increased according to the rice grain size. The RDS (rapidly digestible starch) was highest while the SDS (slowly digestible starch) the lowest in the rice flour porridge. The morphologies of the rice porridges were examined by SEM and showed a smoother surface and more exudated gelatinized granules in the rice flour than in the whole grain rice porridge. In conclusion, rice porridges made from the smallest possible grain size such as flour may be helpful for people with weaker digestive systems such as infants, the elderly, and hospital patients.

• Polymer(Korea)
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• v.28 no.2
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• pp.170-176
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• 2004

The effect of reaction conditions on the size and size distribution of superparamagnetic iron oxide coated with siloxane was big investigated by using dynamic light scattering. The hydrogen bond between the hydroxyl groups on tile surface of the magnetite and silanol was confirmed by FT-IR. The size of nanoparticles increased with the reaction temperature, but decreased with monomer contents and agitation speeds. There was not a big difference in size of nanoparticles, prepared by different reaction conditions, but its distribution was in the range of 14∼41nm. All samples exhibited the superparamagnetic nature. The magnetic susceptibility of the nanoparticles increased with the reaction temperature while it decreased with the monomer content and agitation speed.

• Textile Coloration and Finishing
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• v.27 no.4
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• pp.245-260
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• 2015

The effect of salt milling process on the crystal size, morphology, and color characteristics of C.I. Pigment Red 57:1 was studied. The primitive morphology and color properties of the pigment after synthesis were studied in the former series work. The size and morphology of primary particles and the second aggregation features should be considered because they are very important to determine pigment quality. We compared the primary morphology of pigment particles before drying with the secondary aggregated morphology of pigment particles after drying and salt milling process. Morphological properties were investigated by particle size analysis, X-ray diffraction, and scanning electron microscopy and color measurement was carried out. Significant reduction in particle size as well as enhanced crystallite size after salt milling process was observed. This result might give a difference in color of the pigment, turning into brighter and more blue-toned red color. It was revealed that synthesis condition affect the morphology and color of the pigment even after milling. Increase in HCl concentration in the synthesis process enhanced crystal size and quality forming bluer-red pigments but an increase in $CaCl_2$ concentration resulted in more amorphous crystals forming darker-red pigments after salt milling.

• Journal of the Korean Operations Research and Management Science Society
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• v.31 no.1
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• pp.15-24
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• 2006

In simulation input modeling, it is important to identify a probability distribution to represent the input process of interest. In this paper, an appropriate sample size is determined for parameter estimation associated with some typical probability distributions frequently encountered in simulation input modeling. For this purpose, a statistical measure is proposed to evaluate the effect of sample size on the precision as well as the accuracy related to the parameter estimation, square rooted mean square error to parameter ratio. Based on this evaluation measure, this sample size effect can be not only analyzed dimensionlessly against parameter's unit but also scaled regardless of parameter's magnitude. In the Monte Carlo simulation experiments, three continuous and one discrete probability distributions are investigated such as ; 1) exponential ; 2) gamma ; 3) normal ; and 4) poisson. The parameter's magnitudes tested are designed in order to represent distinct skewness respectively. Results show that ; 1) the evaluation measure drastically improves until the sample size approaches around 200 ; 2) up to the sample size about 400, the improvement continues but becomes ineffective ; and 3) plots of the evaluation measure have a similar plateau pattern beyond the sample size of 400. A case study with real datasets presents for verifying the experimental results.

• Journal of Korean Dental Science
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• v.12 no.1
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• pp.20-28
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• 2019

Purpose: This study was performed to evaluate the effect of voxel size on the accuracy of landmark identification in cone-beam computed tomography (CBCT) images. Materials and Methods: CBCT images were obtained from 15 dry human skulls with two different voxel sizes; 0.39 mm and 0.10 mm. Three midline landmarks and eight bilateral landmarks were identified by 5 examiners and were recorded as three-dimensional coordinates. In order to compare the accuracy of landmark identification between large and small voxel size images, the difference between best estimate (average value of 5 examiners' measurements) and each examiner's value were calculated and compared between the two images. Result: Landmark identification errors showed a high variability according to the landmarks in case of large voxel size images. The small voxel size images showed small errors in all landmarks. The landmark identification errors were smaller for all landmarks in the small voxel size images than in the large voxel size images. Conclusion: The results of the present study indicate that landmark identification errors could be reduced by using smaller voxel size scan in CBCT images.

• Journal of Forest and Environmental Science
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• v.37 no.2
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• pp.141-147
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• 2021

An experiment was conducted to observe the effect of polybag size on the growth and quality of Khaya anthotheca seedlings during September 2016 to June 2017 at the nursery of Silvicultural Research Division of Bangladesh Forest Research Institute. Three different polybag size such as T₁ (15 cm×23 cm), T₂ (13 cm×18 cm) and T₃ (11 cm×15 cm) with four replications were used for the experiment. The experiment was designed in Completely Randomized Design (CRD) with four replications. Different sized polybags showed significant influence on survival percentage (T₁-100%, T₂-93.5%, T₃-88%) and growth parameters (height, root collar diameter, leave number and root length) of the seedlings. The species grown in T₁ size polybag was observed to be superior to other bag size. Dickson's Quality index of seedlings raised in T₁ size polybag was observed highest value which is the indicator of best quality seedlings. Therefore, the use of T₁ poly bag size can be suggested for seedling production of K. anthotheca in the nursery.