• Journal of Soil and Groundwater Environment
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• v.10 no.1
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• pp.26-34
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• 2005

The effects of soil-chemical contact time (aging) on sorption and desorption of atrazine were studied in soil slurries because aging is an important determinant affecting on the sorption and desorption characteristics of organic contaminants in the environment. Sorption isotherm and desorption kinetic experiments were performed, and soilwater distribution coefficients and desorption rate parameters were evaluated using linear and non-linear sorption equations and a three-site desorption model, respectively. Aging time for sorption of atrazine in sterilized soil slurries ranged from 2 days to 8 months. Atrazine sorption isotherms were nearly linear $(r^2\;>\;0.97)$ and sorption coefficients were strongly correlated to soil organic carbon content. Sorption distribution coefficients $(K_d)$ increased with increasing aging in all soils studied. Sorption non-linearity did not increase with increased aging except for the Houghton muck soil. Desorption profiles were well described by the three-site desorption model. The equilibrium site fraction $(f_{eq})$ decreased and the non-desorbable site fraction $(f_{nd})$ increased as a function of aging time in all soils. In all soils studied, it was found that when normalized to soil organic matter content the concentration of atrazine in desorbable sites was comparatively constant, whereas that in non-desorbable site increased as aging increased.

• Korean Journal of Microbiology
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• v.43 no.4
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• pp.250-255
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• 2007

The RecA protein of Deinococcus radiodurans is essential for the extreme radiation resistance of this organism. The central steps involved in recombinational DNA repair require DNA-dependent ATP hydrolysis by recA protein. Key feature of RecA protein-mediated activities is the interactions with ssDNA and dsDNA. The ssDNA is the site where RecA protein filament formation nucleates and where initiation of DNA strand exchange takes place. The effect of sequence heterogeneity of ssDNA was examined in this experiment. The rate of homopolymeric synthetic ssDNA-dependent ATP hydrolysis was constant or nearly so over a broader range of pHs. For poly(dT)-dependent ATP or dATP hydrolysis, rates were generally faster, with a broader optimum between pH 7.0 and 8.0. Activities of RecA protein were affected by the ionic environment. The ATPase activity was shown to have different sensitivity to anionic species. The presence of glutamate seemed to slimulate the hydrolytic activity. Dr RecA protein was shown to require $Mg^{2+}$ ion greater than 2 mM for binding to etheno ssDNA and the binding stoichiometry of 3 nucleotide for RecA protein monomer.

• Korean Chemical Engineering Research
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• v.54 no.6
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• pp.746-752
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• 2016

In this study, soft carbon was prepared by carbonization of carbon precursor (pitch) obtained from PFO (pyrolysis fuel oil) heat treatment. Three carbon precursors prepared by the thermal reaction were 3903 (at $390^{\circ}C$ for 3 h), 4001 (at $400^{\circ}C$ for 1 h) and 4002 (at $400^{\circ}C$ for 2 h). After the prepared soft carbon was ground to a particle size of $25{\sim}35^{\circ}C$, the soft carbon was synthesised by the chemical treatment with boric acid ($H_3BO_3$). The prepared soft carbon were analysed by XRD, FE-SEM and XPS. Also, the electrochemical performances of soft carbon were investigated by constant current charge/discharge test, cyclic voltammetry and impedance tests in the electrolyte of $LiPF_6$ dissolved inorganic solvents (EC:DMC=1:1 vol%+VC 3 wt%). The coin cell using soft carbon of $25{\sim}35^{\circ}C$ with 3903 soft carbon ($H_3BO_3$/Pitch=3:100 in weight) has better initial capacity and efficiency (330 mAh/g, 82%) than those of other coin cells. Also, it was found that the retention rate capability of 2C/0.1C was 90% after 30 cycles.

• Journal of the Korean Geotechnical Society
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• v.27 no.9
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• pp.67-76
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• 2011

Bearing capacity of pile foundations in cold region is dominated by adfreeze bond strength between surrounding soil and pile perimeter. Adfreeze bond strength is considered to be the most important design parameter for foundations in cold region. Many studies in last 50 years have been conducted to analyze characteristics of adfreeze bond strength. However, most studies have been performed under constant temperature and normal stress conditions in order to analyze affecting factors like soil type, pile material, loading speed, etc. In this study, both freezing temperature and normal stress acting on pile surface were considered to be primary factors affecting adfreeze bond strength, while other factors such as soil type, pile material and loading speed were predefined. Direct shear box was used to measure adfreeze bond strength between Joomoonjin sand and aluminium because it is easy to work for various roughness. Test was performed with temperatures of > $0^{\circ}C$, $-1^{\circ}C$, $-2^{\circ}C$, $-5^{\circ}C$, and $-10^{\circ}C$ and vertical confining pressures of 1atm, 2atm, and 3atm. Based on the test results, the effects of temperature and vertical stress on adfreeze bond strength were analyzed. The test results showed that adfreeze bond strength increases with decreased temperature and increased vertical stress. It was also noted that two types of distinct sections exist, owing to the rate of increase of adfreeze bond strength along the change of freezing temperature: 1)rapidly increasing section and 2)gradually decreasing section. In addition, the results showed that a main factor affecting adfreeze bond strength switches from friction angle to adhesion as freezing temperature decreases.

• Korean Journal of Food Science and Technology
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• v.34 no.1
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• pp.24-29
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• 2002

The study was performed to investigate the degrees of gelatinization at various processing steps during the preparation of Dangmyuns using sweet potato, potato, corn and tapioca starches, and also determined the rehydration of the freeze dried sweet potato Dangmyun. The degrees of gelatinization after extrusion cooking showed higher value than other processing steps. The degrees of gelatinization after extrusion cooking were 63.5% in sweet potato, 80.0% in potato, 82.3% in corn, and 86.5% in tapioca Dangmyuns. The degree of gelatinization in Dangmyuns after extrusion cooking step decreased as the processing steps, such as cold storage, freezing, thawing, and sun drying, progressed. L values of color in Dangmyuns decreased in the order of corn>tapioca>potato>sweet potato Dangmyuns. The cooking loss decreased in the order of tapioca>corn>potato>sweet potato Dangmyuns. The percentage of weight gain was the highest in sweet potato Dangmyun followed by corn, potato, and tapioca Dangmyuns. The water absorption rate constant was the highest in sweet potato Dangmyun followed by corn, potato, and tapioca Dangmyuns. In the rehydration of freeze dried Dangmyuns, freeze dried sweet potato Dangmyun showed better than the others. An increase from 60% to 70% of the added amount of water in the mixing step resulted in an increase of the degrees of gelatinization after extrusion cooking from $63.4{\sim}70.7%$ to $73.8{\sim}75.0%$. An increase of the added water in the mixing step and a decrease of diameter in the extrusion cooking step slightly improved the rehydration in the boiled water of freeze dried sweet potato Dangmyun.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.8
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• pp.88-100
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• 1999

Detecting human face and facial landmarks automatically in an image is as essential step to a fully automatic face recognition system. In this paper, we present a new approach to detect automatically face and its eyes of input image with scale and rotation variations of faces by using an intensity based template matching with a single log-polar face template. In a template-based matching it is necessary to normalize the scale changes and rotations of an input image to a template ones. The log-polar mapping which simulates space-variant human visual system converts scale changes and rotations of input image into constant horizontal and cyclic vertical shifts in the output plane. Intelligent use of this property allows us to shift of the candidate log-polar faces mapped at various fixation points of an input image to be matched to a template over the log-polar plane. Thus, the proposed method eliminates the need of adapting multitemplate and multiresolution schemes, which inevitably give rise to intensive computation involved to cope with scale and rotation variations of faces. Through this scale and rotation involved to cope with scale and method can lead to detecting face and its eyes simultaneously. Experimental results on a database of 795 images show over 98% detection rate.

• Journal of Energy Engineering
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• v.23 no.4
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• pp.9-18
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• 2014

These test methods, the current domestic vehicles fuel economy calculation method is tested on a dynamometer for vehicles after you have installed the vehicle, given the test mode(FTP-75 & HWFET mode, etc.) are measured by vehicle emissions and fuel economy by seeking to have the results approach, the carbon balance method. At this point, using the carbon balance method is a test method was developed seeking fuel for a standard fuel properties, where the value of the constant and saved test was measured in THC, CO, $CO_2$ has a value calculation. Therefore, use fuel which is changed every time you test the fuel properties characteristics are not considered exactly. In this study, using the carbon balance method and fluid flow rate of the fuel used in the actual test is measured by comparing the results with the flow measurement methods, properties of the fuel used for the test attribute to study ways that can be considered, taking into account the physical attributes of a more diverse fuel line and fuel economy improved measurement methods that can be reviewed.

• Journal of the Korean Data and Information Science Society
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• v.24 no.6
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• pp.1385-1400
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• 2013

This paper discusses income replacement ratios of national pension, retirement pension and individual annuities in Korea. These ratios are useful indicators for the assessment of retirement income security of workers. This paper projects income replacement ratios, using the pension entry rate, decrement rates, and life tables of the National Statistical Office. The result of the actuarial projection is that the income replacement ratio of national pension is approximately 21.0 to 22.7%, that the income replacement ratio of retirement pension is about 5.8 to 9.7%, and that the income replacement ratio of an individual annuity is about 13.5 to 21.0%, respectively. The income replacement ratio by income varies due to the effects of income redistribution in national pension and retirement pension, but the income replacement ratio of an individual annuity is constant, regardless of income.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.3
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• pp.231-241
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• 2004

This paper drives the exact expression of bit error rate(BER) performance for groupwise iterative-multipath interference cancellation(GWI-MPIC) algorithm for cancelling multipath interference components in a coherent high-speed downlink packet access(HSDPA) system of W-CDMA downlink and the BER performance is evaluated by numerical analysis. The performance of GWI-MPIC is compared to the successive interference cancellation(SIC) algorithm for multipath components. From numerical results, the optimal average BER performance of weighting factor ${\beta}$$\_$h/ for interference cancellation is obtained at ‘${\beta}$$\_$h/=0.8’ and then this weighting factor is hereafter applied to other performance analysis. Numerical results showed that the average BER performance of GWI-MPIC algorithm is rapidly degraded at multipath L=6, but is revealed the good performance than that of SIC algorithm in terms of increasing the number of multipath. This results also indicated that the average BER performance is greatly degraded due to increasing interference power more than multicode K=8. The average BER performance of the proposed algorithm is superior to the performance of SIC algorithm about 3 ㏈ for processing gain PG=128 at multipath L=2 and Average BER=1.0${\times}$10$\^$-5/. And also, the results produced good performance in case of linear monotonic reduction of multipath fading channel gain than that of constant channel gain variation, because multipath fading channel gain which is arrived later is small.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.675-680
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• 2017

Considering that most sewage treatment facilities have a water head of less than 2.0 m and a constant flow rate, the development of a small hydro power generation device capable of maintaining stable power generation and efficiency is urgently needed. In this study, a numerical analysis using the CFD code was carried out to develop a drag force type vertical axis hydro turbine for the improvement of the production efficiency of small-scale hydro energy underlow flow velocity conditions. The blade pressure changes and internal flows were analyzed in the presence or absence of hydro turbine blade holes at a flow velocity of less than 2.0 m/s. The pressure distribution of the hydro turbine blades with holes was found to be about 5.1 % lower than that of the hydro turbine blades without holes. The analysis of the internal flow around the water tank and hydro turbine blade revealed that the flow velocity varied with the vector distribution and that the flow velocity of the hydro turbine blades with holes was 5.6 % less than that of the hydro turbine blades without holes. It is believed that forming a hole in the blade may be helpful for its structural safety.