• Archives of Pharmacal Research
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• v.3 no.2
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• pp.65-74
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• 1980

Analysis of particle size distribution of a sample of fine aluminum hydroxide powder was carried out by four different methods, i. e., conductivity, air permeability, gas-adsorption and sedimentation. Each method was reproducible. The results obtained by Coulter counter and sedimentation balance were similar, and the data obtained by Lea and Nurse permeameter and Stroehlein areameter were also similar. But the results differ considerabley between the former and the latter. The advantages and disavantages of each method were discussed briefly and a means of comparing the results with those obtianed by surface area measurements was shown.

• Journal of Korea Water Resources Association
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• v.53 no.10
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• pp.917-928
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• 2020

The purpose of this study is to find the appropriate probability distribution representing the size distribution of suspended cohesive sediment. Based on goodness-of-fit test for a significance level of 5% using the Kolmogorov-Smirnov test, it is found that the floc size distributions measured in laboratory experiment and field study show different results. In the case of sample data collected from field experiments, the Gamma distribution is the best fitting form. In the case of laboratory experiment results, the sample data shows the positively-skewed distribution and the GEV distribution is the best fitted. The lognormal distribution, which is generally assumed to be a floc size distribution, is not suitable for both field and laboratory results. By using 3-parameter lognormal distribution, it is shown that similar size distribution with floc size distribution can be simulated.

• Geomechanics and Engineering
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• v.14 no.2
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• pp.151-159
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• 2018

Annually, the global production of construction aggregates reaches over 40 billion tons, making aggregates the largest mining sector by volume and value. Currently, the aggregate industry is shifting from sand to hard rock as a result of legislation limiting the extraction of natural sands and gravels. A major implication of this change in the aggregate industry is the need for understanding rock fragmentation and energy absorption to produce more cost-effective aggregates. In this paper, we focused on incorporating dynamic rock and soil mechanics to understand the effects of loading rate and water saturation on the rock fragmentation and energy absorption of three different sandstones (Red, Berea and Buff) with different pore sizes. Rock core samples were prepared in accordance to the ASTM standards for compressive strength testing. Saturated and dry samples were subsequently prepared and fragmented via fast and dynamic compressive strength tests. The particle size distributions of the resulting fragments were subsequently analyzed using mechanical gradation tests. Our results indicate that the rock fragment size generally decreased with increasing loading rate and water content. In addition, the fragment sizes in the larger pore size sample (Buff sandstone) were relatively smaller those in the smaller pore size sample (Red sandstone). Notably, energy absorption decreased with increased loading rate, water content and rock pore size. These results support the conclusion that rock fragment size is positively correlated with the energy absorption of rocks. In addition, the rock fragment size increases as the energy absorption increases. Thus, our data provide insightful information for improving cost-effective aggregate production methods.

• Journal of Nutrition and Health
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• v.17 no.3
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• pp.236-241
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• 1984

In order to make clear the relationship between sample design and sample survey in community, it was conducted research on sample design for National Nutrition Survey in 1983. In this paper it was tried to analize the data based on The Report of a Settled Population, 1981 conducted by National Bureau of Statistics Economic Planning Board. The sample was basically using stratified two-stage sampling with systematic sampling of Ban or Li as administrative unit. The population represents the whole nation excluding Jeju-do because of budget. The selection of sampling unit and sampling procedure was as follows. 1) Stratify the nation-wide area in 20 sections according to administrative districts. 2) Determine the sample size in each section according to equal proportional rate (1 / 8040) and to about 1,000 households in the sample. 3) Select the 25 sampling units by section according to households proportion. 4) Select the 10 households at random from each Ban or Li according to equal probability proportion as the final sampling unit. Using the procedure, it was sampled 1,000 households for National Nutrition Survey in 1983.

• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.541-545
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• 1993

Two different methods (Sieve shaker, Elzone particle size analyzer) were used to investigate rice flour particle size obtained by various milling method. Results of Elzone particle size analyzer were more effective than Sieve shaker in determining particle size, and the distribution of particle size of rice flours was affected by the type of the milling methods used. A rice flour, prepared in a Pin mill had a particle size range of $60{\sim}500$ mesh, and 30.38% of the sample was in the particle size range $200{\sim}270$ mesh. A rice flour, prepared in a Colloid mill had a particle size range of $40{\sim}500$ mesh and more of flour particles appeared in the range $140{\sim}200$ mesh than any other particle size. A rice flour, prepared in a Micro mill had a particle size range of $140{\sim}500$ mesh, and 41.62% of the sample was in the particle size range over 500 mesh. A rife flour, prepared in a Jet mill had a finer flour particle size was over the particle size range 500 mesh. The finer rice flour gave the highest L value and the lowest a value. The wet-milled flour particles were observed as a cluster of starch granules and the particles of rice flour (dry-milling) were observed as fragment of rice grains. Scanning Electron Photomicrographs revealed that visual differences in structure between milling methods, and similar results with Elzone particle size analyzer method in particle size.

• Journal of the Korean Society of Radiology
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• v.17 no.1
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• pp.167-173
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• 2023

X-ray general radiography is the simplest and most important one to get a lot of information. Nevertheless, current x-ray general radiography does not observation in-depth observation. Information about the anatomy of the human body and changes in disease in x-ray general radiography can be obtained but it is difficult to determine the size and shape of the actual lesion due to the disadvantage of expanding the image. In this study, PA and LAT images were acquired and cancer magnification was calculated in the images by measuring the distance of cancer samples. By adjusting the magnification the actual cancer length and thickness were measured and compared with the CT image and the actual cancer sample size. After the PA and LAT images of the inserted 6.0 mm cancer sample were obtained and the magnification was corrected, the length was 5.9 mm and the thickness was 6.1 mm. This value was measured similarly to the actual. The problem of obtaining the magnification that needs to know the actual length from the detector to the cancer sample was secured by obtaining the magnification through PA and LAT images and it is possible to accurately measure the cancer sample size. X-ray general radiography may provide useful information in situations where CT imaging is difficult.

• The Journal of Internal Korean Medicine
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• v.21 no.2
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• pp.319-327
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• 2000

To evaluate the effect of Bangpungdangkwi-eum extracts on reperfusion following the middle cerebral artery occulsion in Sprague Dawley rats, the neuron protection effect were investigated through examining the size of cerebral infarction, cerebral edema, and the morphologic change of neuron. The results were obtained as follows; 1. The size of cerabral infarction in sample group is significantly decreased compared with that in control group. Sample group has approximately 17% cerebral infarction parts induced by ischemia in cerebrum while control group has approximately 22%. 2. The volume of cerebral edema in sample group is significantly decreased compared with that in control group. The volumn in sample group is increased by approximately 4.4% compared with that in normal group while that in control group is increased by approximately 7.7%. 3. The optical microscopic examination reveals that the damage of neurons in the ischemic parts and CA1 and CA3 region of hippocampus in the same side of the ischemic parts was the most high and the damage in sample group is decreased compared with that in control group.

• Human Ecology Research
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• v.55 no.5
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• pp.555-566
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• 2017

This study analyzes the practical tasks and required competency for technical designers to provide basic data on the training of domestic technical designers. The survey was applied to 21 technical designers of big vendors as well as investigated tasks, task flow, important tasks, time-consuming tasks, and required competencies. The results of the study are as follows. First, the technical designers were in charge of several brands of buyers and distributors of fashion companies, or several lines of the same brand. The main production items were cut and sewn knits. Second, the flow of task and tasks were in the order of buyer comments analysis, sloper decision to matching style, sewing specification, productive sewing method research, size specification suggestion, pattern correction comments, construction decision to matching style & fabric, sample evaluations, fit approval, business e-mail writing, specification & grading confirmation, and communication with buyer. Third, five tasks (analysis of buyer comments analysis, communication with buyer, pattern correction comments, productive sewing methods research, sample evaluation) were important and time-consuming tasks. Fourth, reeducation was required in order of sewing, pattern, English, fabric, and fitting. Fifth, competencies to be a technical designers were fitting, pattern correction, size specification & grading, construction & sewing specification, sewing terms & techniques, and communication skills. In conclusion, technical designer training should focus on technology-based instruction, such as sample evaluation, fitting, pattern correction, and productive sewing methods research of cut and sewn knits.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.85.2-85.2
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• 2016

With the advent of ultra-short high-intense XFEL (X-ray Free Electron Laser), time-resolved dynamics has become of great importance in exploring femtosecond real-world phenomena of nanoscience and biology. These include studying the response of materials to femtosecond laser excitation and investigating the interaction of XFEL itself with condensed matter. A variety of dynamic phenomena have been investigated such as radiation damage, ultrafast melting process, non-equilibrium phase transitions caused by orbital-lattice-spin couplings. As far as bulk materials are concerned, the sample size has no effect on the following dynamic process. As a result, imaging information is not required by and large. If the sample size is of tens of nanometers, however, sample starts to experience quantum confinement effect which, in turn, affects the following dynamic process. Therefore, to understand the fundamental dynamic phenomena in nano-science, time-resolved imaging information is essential. In this talk, we will briefly introduce scientific highlights achieved in XFEL-based dynamics. In case of bio-imaging, recent scientific topics will be mentioned as well. Finally, we will aim to present feasible topics in ultrafast time-resolved imaging and to discuss the future plan of CXI beamline at PAL-XFEL.

• The Korean Journal of Applied Statistics
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• v.10 no.2
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• pp.215-226
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• 1997

The purpose of the labor statistics survey is to collect materials on employment, wages and the working time and to analyze the trend of the labor situation. in this research, the stratification variables are industry and the size of establishment. The sample are selected by stratified one stage sampling method in order to produce the reliable estimates of labor statistics. For local labor statistics, we design the sample survey using the city and province as sub-population. So we are able to produce the local area estimates of labor statistics with respect to industry and the size of establishment.