• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.2 s.233
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• pp.169-179
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• 2005

Nucleate boiling experiments on heating surface of constant wall temperature were performed using R113 for almost saturated pool boiling conditions. A microscale heater array and Wheatstone bridge circuits were used to maintain a constant wall temperature condition of heating surface and to measure the heat flow rate with high temporal and spatial resolutions. Bubble images during the bubble growth were taken as 5000 frames per second using a high-speed CCD camera synchronized with the heat flow rate measurements. The bubble growth behavior was analyzed using the new dimensionless parameters for each growth regions to permit comparisons with previous experimental results at the same scale. We found that the new dimensionless parameters can describe the whole growth region as initial and later (thermal) respectively. The comparisons showed good agreement in the initial and thermal growth regions. In the initial growth region including surface tension controlled, transition and inertia controlled regions as divided by Robinson and Judd, the bubble growth rate showed that the bubble radius was proportional to $t^{2/3}$ regardless of working fluids and heating conditions. And in the thermal growth region as also called asymptotic region, the bubble showed a growth rate that was proportional to $t^{1/5}$, also. Those growth rates were slower than the growth rates proposed in previous analytical analyses. The required heat flow rate for the volume change of the observed bubble was estimated to be larger than the heat flow rate measured at the wall. Heat, which is different from the instantaneous heat supplied through the heating wall, can be estimated as being transferred through the interface between bubble and liquid even with saturated pool condition. This phenomenon under a saturated pool condition needs to be analyzed and the data from this study can supply the good experimental data with the precise boundary condition (constant wall temperature).

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.7
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• pp.3-12
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• 2004

The need to predict the rate of soil erosion, both under existing conditions and those expected to occur following soil conservation practice, has been led to the development of various models. In this study Morgan model especially developed for field-sized areas on hill slopes was applied to assess the rate of soil erosion using RS/GIS environment in the Dukchun river basin, one of two tributaries flowing into Jinyang lake. In order to run the model, land cover mapping was made by the supervised classification method with Landsat TM satellite image data, the digital soil map was generated from scanning and screen digitizing from the hard copy of soil maps, digital elevation map (DEM) in order to generate the slope map was made by the digital map (DM) produced by National Geographic Information Institute (NGII). Almost all model parameters were generated to the multiple raster data layers, and the map calculation was made by the raster based GIS software, IL WIS which was developed by ITC, the Netherlands. Model results show that the annual soil loss rates are 5.2, 18.4, 30.3, 58.2 and 60.2 ton/ha/year in forest, paddy fields, built-up area, bare soil, and upland fields respectively. The estimated rates seemed to be high under the normal climatic conditions because of exaggerated land slopes due to DEM generation using 100 m contour interval. However, the results were worthwhile to estimate soil loss in hilly areas and the more precise result could be expected when the more accurate slope data is available.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.120.1-120.1
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• 2012

The Lunar Reconnaissance Orbiter (LRO) launched on June 16, 2009 has six experiments including of the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) onboard. The CRaTER instrument characterizes the radiation environment to be experienced by humans during future lunar missions. The CRaTER instrument measures the effects of ionizing energy loss in matter specifically in silicon solid-state detectors due to penetrating solar energetic protons (SEP) and galactic cosmic rays (GCRs) after interactions with tissue-equivalent plastic (TEP), a synthetic analog of human tissue. The CRaTER instrument houses a compact and highly precise microdosimeter. It measures dose rates below one micro-Rad/sec in silicon in lunar radiation environment. Forbush decrease (FD) event is the sudden decrease of GCR flux. We use the data of cosmic ray and dose rates observed by the CRaTER instrument. We also use the CME list of STEREO SECCHI inner, outer coronagraph and the interplanetary CME data of the ACE/MAG instrument.We examine the origins and the characteristics of the FD-like events in lunar radiation environment. We also compare these events with the FD events on the Earth. We find that whenever the FD events are recorded at ground Neutron Monitor stations, the FD-like events also occur on the lunar environments. The flux variation amplitude of FD-like events on the Moon is approximately two times larger than that of FD events on the Earth. We compare time profiles of GCR flux with of the dose rate of FD-like events in the lunar environment. We figure out that the distinct FD-like events correspond to dose rate events in the CRaTER on lunar environment during the event period.

• Clinical and Experimental Reproductive Medicine
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• v.38 no.1
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• pp.10-17
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• 2011

Objective: To explore potential relationships between sperm DNA integrity and both semen parameters and clinical outcomes. Methods: Semen analysis of 498 samples was performed according to the 2010 criteria of the World Health Organization. The sperm DNA fragmentation Index (DFI) of the semen samples was assessed using a neutral comet assay. Results: Sperm DFI showed a significant correlation with semen parameters, including the patient's age, sperm viability, motility, morphology, and number of leukocytes (p<0.05). The sperm DFI values for asthenozoospermic (15.2%), oligoteratozoospermic (18.3%), asthenoteratozoospermic (17.5%), and oligoasthenoteratozoospermic semen samples (21.3%) were significantly higher than that observed in normozoospermic semen samples (10.5%, p<0.05). A sperm DFI value of 14% was used as a threshold of sperm DFI in assessing whether DNA was highly damaged. In 114 IVF-ET cycles, the fertilization rate of the sperm DFI <14% group (70 cycles, 61.7%) was significantly higher than that observed for the ${\geq}14%$ group (44 cycles, 55.3%), but there was no difference in the other clinical outcomes between the two groups. In the ${\geq}14%$ group, the pregnancy rates of the ICSI cycles (40.0%) and half-ICSI (44.0%) were higher than conventional IVF cycles (30.7%), but the difference was not statistically significant. Conclusion: Along with the conventional semen analysis, the sperm DFI assessed using the comet assay was shown to improve the quality of the semen evaluation. To evaluate the precise effect of ICSI on pregnancy rates in the patients who demonstrate high sperm DFI values, further study is necessary.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.12
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• pp.2719-2730
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• 2009

In this paper, we implement the measurement functionality for performance measurements of EDGE (Enhanced Data Rates for GSM Evolution) terminal by using software. Generally speaking, the receiving algorithms in normal MODEM cannot be used directly to a measurement system due to the lack of accuracy. Therefore, we propose a new receiver algorithm for precise EDGE signal measurements. In the proposed algorithm, 2-stage (coarse stage, fine stage) parameters estimation (symbol-timing, frequency offset, carrier phase) scheme is used. To improve the estimation accuracy, we increase the number of the received signal samples by interpolation. The proposed EDGE signal measurement algorithm can be used for verifying the hardware measurement system, and also can be used for the commercial systems through software optimization.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.284-289
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• 2016

In recent years, the earthquake sequence in Christchurch, New Zealand (NZ) was unprecedented in terms of repeated earthquake shocks with substantial levels of ground motion affecting modern infrastructure, and in particular, broad and precise reports for liquefaction-induced permanent ground deformation (PGD) and repairs of wastewater (WW) pipelines were collected. In this study, a geographical information system (GIS) and linear regression analysis were performed using data for the length and repair points of earthenware (EW) and concrete (CONC) wastewater pipelines acquired after the MW 6.2 February 22, 2011 earthquake. The repair rates (repairs/km) for the EW and CONC wastewater pipelines were evaluated inside the areas of PGD, and both angular distortion of ground and lateral ground strain were calculated from the high resolution LiDAR data acquired before and after the seismic event. The research results showed that both pipelines have similar trends of damage but the CONC wastewater pipeline with higher stiffness showed less damage. The results of linear regression analyses can be used to predict the repair rates for EW and CONC wastewater pipelines inside the areas of PGD induced by future earthquakes.

• Natural Product Sciences
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• v.25 no.1
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• pp.49-58
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• 2019

Eleven steroid hormones (SHs: androstene-3,17-dione, estrone, ${\beta}$-estradiol, ${\alpha}$-estradiol, testosterone, dehydroepiandrosterone, $17{\acute{a}}$-hydroxyprogesterone, medroxyprogesterone, megestrol acetate, progesterone, and androsterone) were detected from New Zealand deer (Cervus elaphus var. scoticus) velvet antler (NZA, 鹿茸 ). A method for the quantification of eleven SHs was established by using ultraperformance liquid chromatography (UPLC)-MS/MS. The linearities ($R^2$ > 0.991), limits of quantification (LOQ values, 0.3 ng/mL to 23.1 ng/mL), intraday and interday precisions (relative standard deviation: RSD < 2.43%), and recovery rates (97.3% to 104.6%) for all eleven SHs were determined. In addition, a method for the quantification of three 7-oxycholesterols (7-O-CSs: 7-ketocholesterol, $7{\alpha}$-hydroxycholesterol, and $7{\beta}$-hydroxycholesterol) in the NZA was established by using an HPLC-photodiode array (PDA) method. The linearities ($R^2$ > 0.999), LOQ values (30 ng/mL to 350 ng/mL), intraday and interday precisions (RSD < 1.93%), and recovery rates (97.2% to 103.5%) for the three 7-O-CSs were determined. These quantitative methods are accurate, precise, and reproducible. As a result, it is suggested that the five steroid compounds of androstene-3,17-dione, androsterone, 7-ketocholesterol, $7{\alpha}$-hydroxycholesterol, and $7{\beta}$-hydroxycholesterol could be marker steroids of NZA. These methods can be applied to quantify or standardize the marker steroids present in NZA.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.6
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• pp.460-464
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• 2000

Extracellular polymeric substances (EPS) are believed to play a role in the binding and formation of microbial flocs. However, the precise role is not well known. Sludge settling characteristics and the carbohydrate to protein ratio in EPS were tested with various airflow rates in this study. Sludge was collected from three modified sequencing batch reactors (SBRs), which were operated at 16$\^{C}$ with an airflow rate of 0.8L/min, 3L/min and 6L/min, respectively. During the operation, the reactor operated at an airflow rate of 0.8L/min showed sludge volume index (SVI) of 80 to 90ml/g and a constant ratio of carbohydrate to protein in the EPS, while a significant increase in the SVI was seen in the other reactors. Sludge bulking increased the amount of carbohydrate in the EPS, while kept protein almost constant in the airflow rate of 3L/min ad 6L/min. Surface charge also increased with increases in the carbohydrate to protein ratio in the EPS, which weakens the attraction between the EPS and multivalent cations. The ratio of carbohydrate to protein in the EPS was tween the EPS and multivalent cations. The ratio of carbohydrate to protein in the EPS was inferred to be essential for bioflocculation.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.16 no.4
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• pp.225-237
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• 2016

In conventional transportation problem (TP), all the parameters are always certain. But, many of the real life situations in industry or organization, the parameters (supply, demand and cost) of the TP are not precise which are imprecise in nature in different factors like the market condition, variations in rates of diesel, traffic jams, weather in hilly areas, capacity of men and machine, long power cut, labourer's over time work, unexpected failures in machine, seasonal changes and many more. To counter these problems, depending on the nature of the parameters, the TP is classified into two categories namely type-2 and type-4 fuzzy transportation problems (FTPs) under uncertain environment and formulates the problem and utilizes the trapezoidal fuzzy number (TrFN) to solve the TP. The existing ranking procedure of Liou and Wang (1992) is used to transform the type-2 and type-4 FTPs into a crisp one so that the conventional method may be applied to solve the TP. Moreover, the solution procedure differs from TP to type-2 and type-4 FTPs in allocation step only. Therefore a simple and efficient method denoted by PSK (P. Senthil Kumar) method is proposed to obtain an optimal solution in terms of TrFNs. From this fuzzy solution, the decision maker (DM) can decide the level of acceptance for the transportation cost or profit. Thus, the major applications of fuzzy set theory are widely used in areas such as inventory control, communication network, aggregate planning, employment scheduling, and personnel assignment and so on.

• Journal of Soil and Groundwater Environment
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• v.18 no.3
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• pp.65-72
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• 2013

Adsorption of melamine was examined using columns packed with granular activated carbon (GAC). Raw GAC was sieved with 20, 40, 60 and 80 mesh to determine the influence of adsorbent particle size on reaction and diffusion. The mass ratio of the adsorption capacity of GAC for melamine ranged from 9.19 to 11.06%, and adsorption rates increased with decreasing particle size within this range. Rate constants between 3.295 ~ 4.799 $min^{-1}$ were obtained using a pseudofirst-order equation that was used to determine adsorption kinetics. A surface diffusion model was adapted to take into account the unsteady-state equation of a spherical adsorbent by converting the surface concentration from a constant to a variable governed by a dispersion equation. The calculated values were fit with the experimental results by using the diffusion coefficients as regression parameters. The modified equation exhibited a more precise agreement with respect to the sum of the absolute error (SAE).