• Journal of the military operations research society of Korea
• /
• v.4 no.1
• /
• pp.57-68
• /
• 1978

In forecasting the demand rate of repair parts for old tank types under the limited historical data, this reportan alyzes which techniques give the smallest forecasting error, also economic repair limits and the return for additional repair costs are formulated as a mathematical model

• Bulletin of the Korean Mathematical Society
• /
• v.48 no.3
• /
• pp.611-616
• /
• 2011

The reflexiveness and reversibility were introduced by Mason and Cohn respectively. The structures of minimal reversible rings and minimal reflexive rings are completely determined. The term minimal means having smallest cardinality.

• Journal of applied mathematics & informatics
• /
• v.4 no.1
• /
• pp.31-38
• /
• 1997

We figure out geometric properties of the Julia set $J_{\alpha}$ of cubic complex polynomial $C_{\alpha}(z)=z^3 + {\alpha}z(\alpha \epsilon \mathbb{C})$ and the smallest ellipse which surrounds $J_{\alpha}$.

• Communications for Statistical Applications and Methods
• /
• v.16 no.1
• /
• pp.137-141
• /
• 2009

We study on selecting the kernel weighting function in smoothing moment conditions for dependent processes. For hypothesis testing in Generalized Method of Moments or Generalized Empirical Likelihood context, we find that smoothing moment conditions by Bartlett kernel delivers smallest size distortions based on empirical Edgeworth expansions of the long-run variance estimator.

• Archives of Pharmacal Research
• /
• v.29 no.7
• /
• pp.556-562
• /
• 2006

Ten semi-synthetic derivatives of asiatic acid were prepared and their wound healing effects were evaluated by employing a tensile strength assay and a wound area assay. Among them, ethoxymethyl 2-oxo-3,23-isopropylidene-asiatate (12) showed the strongest and the fastest wound healing activity. Furthermore, it left the smallest scar after healing.

• Journal of Microbiology
• /
• v.44 no.5
• /
• pp.530-536
• /
• 2006

Bacteriophage P4, a satellite phage of coliphage P2, is a very useful experimental tool for the study of viral capsid assembly and cos-cleavage. For an in vitro cos-cleavage reaction study of the P2-P4 system, new shortened and selectable markers containing P4 derivative plasm ids were designed as a substrate molecules. They were constructed by swapping the non-essential segment of P4 DNA for either the kanamycin resistance (kmr) gene or the ampicillin resistance (apr) gene. The size of the genomes of the resulting markers were 82% (P4 ash8 delRI:: kmr) and 79% (P4 ash8 delRI:: apr) of the wild type P4 genome. To determine the lower limit of genome size that could be packaged into the small P4-size bead, these shortened P4 plasmids were converted to phage particles with infection of the helper phage P2. The conversion of plasmid P4 derivatives to bacteriophage particles was verified by the heat stability test and the burst size determination experiment. CsCl buoyant equilibrium density gradient experiments confirmed not only the genome size of the viable phage form of shortened P4 derivatives, but also their packaging into the small P4-size head. P4 ash8 delRI:: apr turned out to be the smallest P4 genome that can be packaged into P4-sized head.

• International Journal of Korean Welding Society
• /
• v.4 no.1
• /
• pp.15-22
• /
• 2004

Metal transfer behavior of three shielded metal arc welding electrodes, AWS El1018, E6013 and E6010, were investigated through the characterization of size distribution of droplets and measurement of arc voltage signals. Of the three electrodes, Ell018 electrode showed the largest droplet size with the smallest amount of spatter, while E6010 electrode showed the smallest droplet size with the largest amount of spatter. Even though Ell0l8 electrode showed a good agreement between the frequencies of voltage drop in FFT processed voltage signals and the transfer rate of droplets, E6013 and E6010 electrodes showed weaker correlation because of their dominant explosive transfer behavior. The type of cathode used and electrode baking time also influenced the metal transfer behavior. Compared to bead-on-plate welding using steel plate as a cathode, welding on a water-cooled copper pipe showed less short-circuiting and higher melting rate in all electrodes because of higher arc potential and/or anode drop. When baked for a long time, E6010 electrode showed much more stable arc with less short-circuiting and explosion due to the loss of gas formation ingredients.

• KSBB Journal
• /
• v.29 no.5
• /
• pp.385-391
• /
• 2014

In this study, the emulsion dispersion stability of optimizing storage temperature was investigated. The system was based on oil/water (O/W) emulsions. In order to evaluate the stability, mean diameter of droplet was measured as a function of temperature with various mixed hydrophilic lipophilic balance (HLB). In addition, the correlations between phase inversion temperature (PIT) and the optimum storage temperature were probed. In this system, majority of the smallest droplet was shown at temperature of $20^{\circ}C$ below PIT. Whether the temperature was increased or decreased from the optimum, size of the droplet increased. According to the mixed HLB, the particle size and optimum storage temperature were also affected. As the concentrations of surfactant were increased, the size of particle decreased with lower optimum temperature for storage. If the surfactant (4 wt%) were mixed with HLB, the optimum storage temperature was $21^{\circ}C$ for maintaining the size of smallest droplet at 108.3 nm in diameter. At above optimum condition, increased size of particle was observed approximately 4 % increases from 108.2 nm to 112.3 nm after 600 hours. The size of particle in emulsion was maintained stably without any considerable effect of Ostwald ripening phenomena at the optimum storage temperature with low polydispersity index.

• Journal of the Korean Society of Costume
• /
• v.40
• /
• pp.81-93
• /
• 1998

It is necessary to research shape of the breast of girls at adolescence for developing well-fit brassiers. 313 participants reside in Chonju and Kunsan were gathered for body measurement. The conclusion of this study can be summarized as follows. 1) The Analysis of Body Shape by Measurement. Comparing Age GroupⅠ(aged 10 to 12)' measurement with Age GroupⅡ(aged 13 to 15)', Each items has statistical significance. Two groups differed in the length, girth, depth, width items. 2) Factor Analysis of Body Measurement (1) Age GroupⅠ'characteristics were categorized Three Factor : Breast size and breast apex length. Breast volume, Length of the Breast part. (2) Age GroupⅡ' characteristics consist of four factors, which are named as breast size and its jut (first factor), breast volume (second factor), contour of breast profile & its jut (third factor), shoulder length (fourth factor). 3) Characteristics of Breast Shape. (1) Breast shapes of Age GroupⅠ are classified into three types. Types 1 is a protruded and more voluminous shape. Type 2 is the most voluminous and breast fatness is highest. Type 3 is the smallest and flat shape growing now. (2) Breast shapes of Age GroupⅡ are also classified into three types. Type 1 is the longest in length and middle in fatness, voluminous in size. Type 2 is the smallest in stature and the slimmest in fatness in breast shape. Type 3 is middle in length, the fattest and the most voluminous in breast.

• Journal of Sensor Science and Technology
• /
• v.27 no.3
• /
• pp.199-203
• /
• 2018

In this study, we develop a methane sensor module that can detect low concentrations below 5,000 ppm and measure up to the detection limit of 50 ppm with the NDIR method, with a long lifetime and high accuracy. Methane ($CH_4$) is one of a representative greenhouse gas, which is very explosive. Thus, it is important to quickly and accurately measure methane concentration in the air. To adjust the methane sensor for industrial field applications, a NDIR-based small sensor was implemented and characterized, where its volume was $4cm{\times}4cm{\times}2cm$ and its response time ($T_{90}$) was less than 30 sec. These results demonstrate that the proposed sensor is commercially available for low-concentration measurement, low volume, and fast response application, such as IoT sensor nodes and portable devices.