• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.704-705
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• 2006

Discrete element analysis is used to map various log-normal particle size distributions into measures of the in-sphere pore size distribution. Combinations evaluated range from monosized spheres to include bimodal mixtures and various log-normal distributions. The latter proves most useful in providing a mapping of one distribution into the other (knowing the particle size distribution we want to predict the pore size distribution). Such metrics show predictions where the presence of large pores is anticipated that need to be avoided to ensure high sintered properties.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.6
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• pp.447-453
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• 2009

Vegetation distribution and soil salinity were surveyed on the conservation plot in the Daeho reclaimed tidal land, in where the plants species distribution was more various than a periodically inundated tidal flat and the early stage of reclamation. According to the soil salinity where the vegetation patches were occurred, the mono patches of Salicornia europaea, Suaeda maritima, and Suaeda glauca were distributed in the average range of 31.05 dS/m in soil salinity, the mixed patches of them were distributed in the average range of 42.75 dS/m. Therefore, Salicornia europaea, Suaeda maritima, and Suaeda glauca showed strong salt tolerance. The mono patches of Aster tripolium, Sonchus brachyotus, and Scirpus planiculm were distributed in the range of 11.73 dS/m in soil salinity, and the mixed patches were distributed in the average range of 9.43 dS/m. Therefore Aster tripolium, Sonchus brachyotus, and Scirpus planiculmis showed moderate salt tolerance. The mono patches of Imperata cylindrica, Trifolium pratense, Miscanthus sinensis, Setaria viridis, and Trisetum bifidum were distributed in the range of 2.42 dS/m in soil salinity. These species showed characteristics of glycophytes with weak salt tolerance. The distribution of vegetation patches was influenced by the soil salinity as pioneer halophytes patches occurred at higher soil salinity zone than facultative halophytes patches, glycophytes patches occurred at lower soil salinity zone than facultative halophytes. These results suggested that occurrence of plant species and plant distribution type might be useful index to evaluate the soil salinity and desalinization in the reclaimed land of the midwest coastal area of Korea.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.E1
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• pp.1-7
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• 2001

The elemental characteristics of atmospheric aerosols were investigated as a function of particle size and water solubility. The aerosol particles were samples at 12 individual size ranges between 0.01 and 30㎛. Collected aerosol particles were separated into both soluble and insoluble components. The concentrations of 15 elements in both components were determined by a PIXE analysis using a 2.0 MeV-proton beam. In general, the mass size distribution of particulate matter was represented as a bimodal distribution. The maximum rations of S in July and December were 5.5 and 3.8 %, and they appeared in the size range of 0.47∼1.17㎛(stage No. 6 or 7) . The ratios of a S at non-separated size were 3.1 and 2.2 % in July and December, respectively, On the other hand, the maximum rations of Si in July and December were 7.0 and 5.4% and they appeared in the size range of 5.1∼30㎛(stage No. 0∼2). The ratios of Si at the non-separated size were 2.1 and 1.8% in July and December, respectively, The mass diameter of 12 elements ranged between 0.59㎛ of S and 3.20 of Fe. More than 90% of atmospheric aerosols consisted of the light elements such as C, N, O, H and Al. The soluble component was dominant in the smaller size range and the insoluble component in the larger size range. Large portions of Si. Ti and Fe existed in insoluble state. By contrast, S, Cl, Ca, Zn and Br were dissolved in water.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.260-262
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• 2002

An accurate measurement of dose distribution is indispensable to perform radiation therapy planning. A measurement technique using a radiographic film, which is called a film dosimetry, is widely used because it is easy to obtain a dose distribution with a good special resolution. In this study, we tried to develop an analyzing system for the film dosimetry using usual office automation equipments such as a personal computer and an image scanner. A film was sandwiched between two solid water phantom blocks (30 ${\times}$ 30 ${\times}$ 15cm). The film was exposed with Cobalt-60 ${\gamma}$-ray whose beam axis was parallel to the film surface. The density distribution on the exposed film was stored in a personal computer through an image scanner (8bits) and the film density was shown as the digital value with NIH-image software. Isodose curves were obtained from the relationship between the digital value and the absorbed dose calculated from percentage depth dose and absorbed dose at the reference point. The isodose curves were also obtained using an Isodose plotter, for reference. The measurements were carried out for 31cGy (exposure time: 120seconds) and 80cGy (exposure time: 300seconds) at the reference point. While the isodose curves obtained with our system were drawn up to 60% dose range for the case of 80cGy, the isodose curves could be drawn up to 80% dose range for the case of 31cGy. Furthermore, the isodose curves almost agreed with that obtained with the isodose plotter in low dose range. However, further improvement of our system is necessary in high dose range.

• The Korean Journal of Applied Statistics
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• v.26 no.6
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• pp.987-998
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• 2013

This paper considers the statistical characteristics on the air quality (PM10) of Korea collected hourly in 2011. PM10 in Korea exhibits very strong correlations even for higher lags, namely, long range dependence. It is power-law tailed in marginal distribution, and generalized Pareto distribution successfully captures the thicker tail than log-normal distribution. However, slowly decaying autocorrelations may confuse practitioners since a non-stationary model (such as changes in mean) can produce spurious long term correlations for finite samples. We conduct a statistical testing procedure to distinguish two models and argue that the high persistency can be explained by non-stationary changes in mean model rather than long range dependent time series models.

• Journal of the Korean Society of Clothing and Textiles
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• v.28 no.11
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• pp.1361-1371
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• 2004

This was a follow-up study to the 'Study on the Body Types of Chinese Adult Women I,' which looked into the body types and classified them into representative body type groups, with the subjects of the women residing in Beijing and Shanghai, and it intends to compare the features of the body types by the residential area of each age range. The results were as follows: 1. The measurements physical items of the women residing in Beijing and Shanghai were compared by the age range, and differences were found in all age ranges. In particular, as the age ranges got higher, the differences in the physical measurements were significant. 2. The comparison of the factor score for the women residing in Beijing and Shanghai by the age range indicated the differences in all the age ranges, and the differences were larger as the age got higher. 3. The comparison of the type distribution for the women residing in Beijing and Shanghai by the age range indicated the differences in their 30's and 40's, while any differences in the type distribution were not found in their 20's.

• Journal of Distribution Science
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• v.14 no.12
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• pp.5-21
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• 2016

Purpose - This study aims to clarify the meanings of small enterprise and modify criteria for explaining its range. Prioritizing the number of full time workers first and the sales next are proper as a new concept and range. Research design, data, and methodology - In research, 'small company' is a basic concept because the range of its standard is categorized as a 'small company' in the policy system of small & medium business. This study focuses on the solutions with ① evaluation on sales, ② standard for excluded ones ③ regulation for excluded business types in 'Act on Protection and Support for Small Enterprise'. Results - Clarifying the range of standard with maintaining the title is advisable. The scope should resist the current criteria or adopt a new standard which contains not only full time workers but also the sales. The new one may raise the policies' effectiveness because it can sort the 1% people of small enterprises. Conclusions - However, there should be a preventive system for sorting out the non-eligible ones not conformed to the CAP for small company. Therefore, it is desirable to prepare the system with 'unsuitable ones list' or regulate large income·inappropriate business types in 'Act on protection and support for small enterprise'.

• The Journal of the Korean life insurance medical association
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• v.3 no.1
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• pp.219-232
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• 1986

A study on establishment of normal range of cardiothoracic ratio calculated from photofluorography film of chest by age and sex in a total of the 6,598 insureds was undertaken. The results were as follows: 1. In male group, the frequency distribution of cardiothoracic ratio was skewed weakly to the right in second decade, symmetrical in third and fourth decade, and was skewed weakly to the left in fifth and sixth decade; in female group, it was skewed weakly to the left in second, third and fourth decade, and was skewed weakly to the right in fifth and sixth decade. 2. On assumption that normal range of cardiothoracic ratio should comprise about 85% of all cardiothoracic ratios in each age group of both sexes, the sites of deviation from mean value of cardiothoracic ratio corresponding to maximum and minimum cardiothoracic ratio in the range of about 85% above mentioned were detected by statistical method on the frequency distribution of log tranformed cardiothoracic ratio, and $M{\pm}1.3$ sindicating normal range of cardiothoracic ratio was determined. In male group, normal range of cardiothoracic ratio determined by statistical method is 35-45%, 40-50%, 40-50%, 40-50% and 40-50% succesively in order from second to sixth decade; in female group, 40-50%, 40-50%, 40-50%, 45-55% and 45-55%.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.1
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• pp.159-168
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• 2008

A special field experiment has been carried out from March 2001 to June 2001 at the Changhowon in Kyunggi to investigate a better methodology for the estimation of dry deposition of pollutions applicable in Korea. In this study, dry deposition plate was used to measure of total and water soluble acidic mass fluxes, and CPRI(Coarse Particle Rotary Impactor), CI(Cascade Impactor) were also used to measure ambient concentrations in various particle size ranges. Sehmel-Hodgson model was used to estimate dry depostion velocity and Weibull probability distribution function was applied to get generalized particle size distribution for the size fractioned concentration data sampled by CPRI and CI. Atmospheric dry deposition fluxes of mass and ionic matters estimated by the various techniques(one-step, multi-step, equi-concentration, subdivision for only the coarse particle range, applying Weibull distribution function, etc.) were compared to flux data sampled by DDP. It was found out that the deposition fluxes estimation methodology calculated by the each particle size range devided by particle size distribution characteristics and the rapidly changed points of deposition velocity using Weibull probability distribution function was the most applicable.

• Journal of Advanced Marine Engineering and Technology
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• v.26 no.3
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• pp.313-319
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• 2002

Since the oil crisis in 1970, a great deal of effort has been made to develop automatic electric load sharing systems as a part of the efforts to save energy. A large scale electric generating system composes more than two generators whose characteristics may be different. When such a system is operated individually or in parallel, the lagrange multiplier's method has difficulty in achieving optimal load distribution because generators usually have the limitations of the operating range with inequality constraints. Therefore, a suitable operating mode of generators has to be decided according to the selection of the generators to meet electric power requirements at the minimum cost. In this study, a method which solves the optimal electric load distribution problem using the dynamic programming technique is proposed. This study also shows that the dynamic programming method has an advantage in dealing with the optimal load distribution problem under the limitations of the operating range with inequality constraints including generator operation mode. In this study, generator operating cost curve of second order equation by shop trial test results of diesel generators are used. The results indicate that the proposed method can be applied to the ship's electric generating system.