• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1129-1129
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• 2001

Maize, in Hungary, is the fodder-plant grown in the biggest quantity. It is not only used as a fodder but other products such as iso-sugar are made from it, too. The quality of the fodder and the produce is largely dependent on the composition of the supplied maize to the processing site. The examination of quality parameters besides conventional methods are investigated and measured by NIR spectroscopy on a routine basis. The investigated parameters are the following: water, total protein, starch and oil content. The accuracy and precision of determining these parameters we, apart from the wet chemical methods, influenced by sample preparation to a great extent. One of the main features of this is the sample particle size and its distribution across the sample. The uneven distribution of particle size negatively influences the measurement accuracy, decreases model robustness and prediction ability. With these in mind the aim of our experiment was to investigate the effect of particle size on the accuracy of maize composition determination using reflection measurement setup. In addition, we tested different spectrum transformations, which are suitable for canceling this effect. In our experiment 47 samples were analyzed with three different mesh sizes (1.5mm, 1.8mm and 2mm). The results of our findings are presented here.

• Journal of Integrative Natural Science
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• v.14 no.3
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• pp.123-129
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• 2021

This research examines the effect of positively skewed population distribution on the two sample t-test through simulation. For simulation work, two independent samples were selected from the same chi-square distributions with 3, 5, 10, 15, 20, 30 degrees of freedom and sample sizes 3, 5, 10, 15, 20, 30, respectively. Chi-square distribution is largely skewed to the right at small degrees of freedom and getting symmetric as the degrees of freedom increase. Simulation results show that the sampled populations are distributed positively skewed like chi-square distribution with small degrees of freedom, the F-test for the equality of variances shows poor performances even at the relatively large degrees of freedom and sample sizes like 30 for both, and so it is recommended to avoid using F-test. When two population variances are equal, the skewness of population distribution does not affect on the t-test in terms of the confidence level. However even though for the highly positively skewed distribution and small sample sizes like three or five the t-test achieved the nominal confidence level, the error limits are very large at small sample size. Therefore, if the sampled population is expected to be highly skewed to the right, it will be recommended to use relatively large sample size, at least 20.

• Korean Journal of Veterinary Research
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• v.50 no.1
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• pp.43-48
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• 2010

Animal disease surveillance system, defined as the continuous investigation of a given population to detect the occurrence of disease or infection for control purposes, has been key roles to assess the health status of an animal population and, more recently, in international trade of animal and animal products with regard to risk assessment. Especially, for a system aiming to determine whether or not a disease is present in a population sensitivity of the system should be maintained high enough not to miss an infected animal. Therefore, when planning the implementation of surveillance system a number of factors that affecting surveillance sensitivity should be taken into account. Of these parameters sample size is of important, and different approaches are used to calculate sample size, usually depending on the objective of surveillance systems. The purpose of this study was to evaluate the sensitivity of the current national serological surveillance programs for four selected bovine diseases assuming a specified sampling plan, to examine factors affecting the probability of detection, and to provide sample sizes required for achieving surveillance goal of detecting at least an infection in a given population. Our results showed that, for example, detecting low level of prevalence (0.2% for bovine tuberculosis) requires selection of all animals per typical Korean cattle farm (n = 17), and thus risk-based target surveillance for high risk groups can be an alternative strategy to increase sensitivity while not increasing overall sampling efforts. The minimum sample size required for detecting at least one positive animal was sharply increased as the disease prevalence is low. More importantly, high reliability of prevalence estimation was expected with increased sampling fraction even when zero-infected animal was identified. The effect of sample size is also discussed in terms of the maximum prevalence when zero-infected animals were identified and on the probability of failure to detect an infection. We suggest that for many serological surveillance systems, diagnostic performance of the testing method, sample size, prevalence, population size, and statistical confidence need to be considered to correctly interpret results of the system.

• Applied Chemistry for Engineering
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• v.9 no.3
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• pp.430-434
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• 1998

Preparative HPLC (High-Performance Liquid Chromatography) is mainly used for separating useful component from biological samples. By reversed-phase HPLC packed with preparative packings ($15{\mu}m$), the adsorption characteristics with sample size were investigated. Sample was 5'-GMP, a flavor enhancer, and the composition of mobile phase was 20mM $KH_2PO_4$ solution:methanol (97:3 vol.%). From the experimental results, the effect of sample size on retention factor was negligible, but the peak was asymmetrical above $1{\mu}g$ of sample. In addition, the increase in sample size deteriorated the number of theoretical plates, and at small concentration, the number of theoretical plates was less because of large peak width. In the experimental condition, the adsorption isotherm of 5'-GMP was relatively well represented by Freundlich equation.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.9 no.1
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• pp.20-29
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• 2004

Macrobenthos species-area relationship was investigated and empirical models were estimated to enable comparisons among species numbers of different sample size. The study aims to choose a way to predict cumulative relative species number (CRSN) in a given sample size Saemangeum, located in the west coast of South Korea, were visited in Apr., May and Aug.,2002 and a total of 261 biological samples from 87 stations were obtained by employing a quantitative sediment sampler, Smith-McIntyre grab and design of 3 replicates at each station. Relative species numbers (%) were baselined at sample size of 1000 $\textrm{cm}^2$ and the patterns of CRSN along the axis of sample size were measured and observed. In correlation analysis performed on a set of abiotic and biotic variables, log-transformed CRSN showed the only significant relationship with log-transformed density. Based on the result, three models, Log CRSN 2000, Log CRSN 3000 and Log CRSN were produced. The former two were devised to predict CRSN at 2000 and 3000 $\textrm{cm}^2$ respectively, and the latter at various sample sizes and samplers (all p-values were <0.001). Database from other studies (intertidal or subtidal macrofaunal samples from Kyonggi Bay and Saemangeum) were used to evaluate validity of the models. Observed CRSN below sample size of 3000 $\textrm{cm}^2$ fell under the range of 95% prediction interval and this was appeared to provide reliability of the models below that sample size.

• Journal of Korean Academy of Nursing
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• v.27 no.4
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• pp.857-870
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• 1997

The purposes of this study were to describe 12 years of patient-related oncology nursing research in Korea, identifying various nursing interventions, and assesing the effectiveness of the interventions, through analysis and synthesis of the accumulated research papers. One hundred and seventy-nine studies were selected for this study and these were mostly descriptive in design (69.2%). Of the 179 studies, 25 met the criteria for meta-analytic treatment. Twenty-five experimental studies were found in theses and dissertations (68%), 92% used convenience sample, and the median sample size was 40. Subjects were predominantly in treatment and rehabilitation (76%). Most studies(68%) were not derived from a theory base, with only 8% reporting use of a nursing theory. Results of the meta-analysis are as follows. The effect size of the nursing intervention type was found to be significantly effective. The standardized mean difference ranged from a high positive of 2.55 to a low negative of -0.22. Direct personal nursing intervention method was more effective than indirect group method. Two nursing intervention methods were more effective than one. The greatest effect size was thyxical intervention. The greatest mean effect size was scalp hypothermia technique. Teaching was a frequent intervention after 1990, although a wide range of treatments were studied. Effect size of intervention for symptom management was largest in relieving pain. Effective intervention method for relieving anxiety was exercise.

• Korean Journal of Exercise Nutrition
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• v.23 no.1
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• pp.36-47
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• 2019

[Purpose] We conducted a meta-analysis to evaluate the effects of Taekwondo training on the physical fitness factors in Korean elementary students comprehensively and quantitatively. [Methods] We classified research studies published until November 2018 according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and selected a total of 17 research items; a meta-analysis of these items was then conducted. We used the Comprehensive Meta-Analysis 3.0 and Review Manager 5.3 to analyze the mean effect size, study quality, and publication bias. [Results] Taekwondo training improved the cardiopulmonary endurance, muscle endurance, and power of the elementary students, but was not practical or less useful on other physical fitness factors. The meta-regression analysis of the cardiopulmonary endurance and power items showed that the effect size was large when the sample size was small. Therefore, it is necessary to consider the sample size in interpreting the effect size for these two items. Further, during correction of the publication bias for the power items, the improvement effect by Taekwondo training was eliminated. [Conclusion] Taekwondo training is helpful for improving the cardiopulmonary endurance and muscle endurance of Korean elementary students but is not useful for other physical fitness factors.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.1
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• pp.95-104
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• 2017

This paper deals with solution methods for discrete and multi-valued optimization problems. The objective function of the problem incorporates noise effects generated in case that fitness evaluation is accomplished by computer based experiments such as Monte Carlo simulation or discrete event simulation. Meta heuristics including Genetic Algorithm (GA) and Discrete Particle Swarm Optimization (DPSO) can be used to solve these simulation based multi-valued optimization problems. In applying these population based meta heuristics to simulation based optimization problem, samples size to estimate the expected fitness value of a solution and population (particle) size in a generation (step) should be carefully determined to obtain reliable solutions. Under realistic environment with restriction on available computation time, there exists trade-off between these values. In this paper, the effects of sample and population sizes are analyzed under well-known multi-modal and multi-dimensional test functions with randomly generated noise effects. From the experimental results, it is shown that the performance of DPSO is superior to that of GA. While appropriate determination of population sizes is more important than sample size in GA, appropriate determination of sample size is more important than particle size in DPSO. Especially in DPSO, the solution quality under increasing sample sizes with steps is inferior to constant or decreasing sample sizes with steps. Furthermore, the performance of DPSO is improved when OCBA (Optimal Computing Budget Allocation) is incorporated in selecting the best particle in each step. In applying OCBA in DPSO, smaller value of incremental sample size is preferred to obtain better solutions.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.65-67
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• 2015

The surfaces of most atmosphereless solar system objects are referred to as regolith, layers of loosely connected fragmentary debris, produced by meteorite impacts. Measurements of light scattered from such surfaces provides information about the composition and structure of the surface. A suitable way to characterize the scattering properties is to consider how the intensity and polarization of scattered light depends on the particle size, composition, porosity, roughness, wavelength of incident light and the geometry of observation. In the present work, the effect of porosity on bidirectional reflectance as a function of phase angle is studied for alumina powder with grain size of $0.3{\mu}m$ and olivine powder with grain size of $49{\mu}m$ at 543.5 nm. The optical constants of the alumina sample for each porosity were calculated with Maxwell Garnett effective medium theory. On using each of the optical constants of alumina sample in Mie theory with the Hapke model the variation of bidirectional reflectance is obtained as a function of phase angle with porosity as a parameter. Experimental reflectance data are in good agreement the model. For the olivine sample the effect of porosity is studied using Hapke (2008).

• Korean Journal of Metals and Materials
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• v.49 no.7
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• pp.530-534
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• 2011

To analyze the effect of the pore size of graphite in a pore-forming agent, graphite was added to porous ceramics of $Al_2O_3-SiO_2-ZrO_2$ systems. The graphite had 45~75, 100~125, 150~180, and 75~180${\mu}m$ dimensions. The properties of the ceramics, such as apparent porosity, density, dynamic elastic modulus, mechanical strength, and permeability, were investigated. The average pore size increased from 15.35${\mu}m$ to 22.32${\mu}m$ with the increase of the graphite size. The sample with the largest average pore size showed the highest mechanical strength and gas permeability. This was due to the sample with the largest pore size at the same porosity having fewer pores and larger distance between the pores than the sample with the smallest pore size, making cracks less likely to propagate. In addition, the large pore size reduced the repulsive power originating from the drag force between the gas and internal pore walls.