• Journal of the Korean Wood Science and Technology
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• v.24 no.4
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• pp.1-6
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• 1996

Extracts from bark have been studied with a view to producing water-proof wood adhesives. Lately many softwoods, such as radiata pine from New Zealand and larch from Siberia, Russia, have been imported and utilized, and their residual barks would be expecting as potential raw materials for something useful chemicals. The great effort toward utilization of bark extractives as a chemical feedstock has been made on a worldwide level. However few report has been done for the utilization of tree bark extractives in Korea. Hot-water extracts were prepared from barks of Japanese larch(Larix leptolepis). Siberian larch(Larix gmelinii) and Radiata pine(Pinus radiata). The effect of various factors, such as particle size, liquor ratio, extraction temperature, and reaction time, on the extractive yields was discussed. Particle sizes affected the hot-water extractives: the finer the particle size, the higher extractives and extract efficiency. Higher temperature and higher liquor ratio were more effective. Extractives from Japanese larch were relatively less than those from Siberian larch and Radiata pine barks. Formaldehyde precipitates was the highest in extractives of Radiata pine barks. It could be concluded that Siberian larch bark was the best raw material for tannin adhesives, because its extractive yield was higher than those of the other barks.

• Journal of Korean Society of Water and Wastewater
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• v.10 no.4
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• pp.119-126
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• 1996

Influence factors and efficiency characteristics for treatment of wastewater containing phenol were studied with using Pseudomonas sp. B3. It took 130 hours to remove phenol, when only activated sludge of terminal disposal palnt of sewage was innoculated in batch culture, but it was required just 36 hours, when bacteria degrading phenol and activated sludge were simultaneously innoculated. If only phenol an carbon source was used, it necessary 36 hours for biodegradation of phenol, while glucose was added to medium, it took 73 hours. It was revealed as excellent effluent and SVI, when the F/M ratio, COD and phenol concentration were 53mg/l and 1.2mg/l, respectively, and optimum F/M ratio was revealed 0.31. The reactor were seriously shocked as reducing hydraulic retention time at constant phenol concentration more than increasing phenol concentration at constant hydraulic retention time, when volumetric loading rate was increased to $0.8kg\;phenol/m^3{\codt}d$ from $1.6kg\;phenol/m^3{\codt}d$. And also the effluent phenol concentration was 34mg/l after starting 12 hours of shocking and reactor was recovered as steady state after 65 hours of changing in the former test. Although the effluent phenol concentration was maximum value with 12mg/l after starting 20 hours of shocking and reactor was recovered as steady state after 54 hours of changing in the later test.

• Korean journal of food and cookery science
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• v.26 no.5
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• pp.545-551
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• 2010

In this study, Sulgidduk samples were prepared with 0%, 3%, 5% and 7% yacon powder. Sulgidduk samples were then examined for quality characteristics such as moisture content, general components, color, texture profile analysis, sensory qualities, and sugar content, in order to determine the optimal ratio of yacon powder in the formulation. Regarding the general components of yacon Sulgidduk, the contents of crude protein and lipid decreased as the ratio of yacon powder increased. The L-value for color decreased, whereas a- and b-values increased. In the texture profile analysis, 7%-added yacon showed significantly lower hardness, whereas 7% yacon powder showed the highest values for cohesiveness, springiness, and chewiness. The contents of sucrose, fructose, and glucose in yacon Sulgidduk were found to be 3%, 5%, and 7% by LC, respectively. Sucrose showed a decreasing trend with increased yacon powder content, but fructose and glucose increased with increased amount of yacon powder. For sensory qualities, taste/flavor, texture, hardness, and overall acceptability were not significantly different among the 0%, 3%, and 5% yacon powder samples.

• Proceedings of the KSR Conference
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• 2003.10b
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• pp.73-78
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• 2003

As a fundamental study to develop the retaining wall of new type, short-fibers are mixed with soils and a series of compaction tests and triaxial compression tests for short-fiber reinforced soils are performed. From the results of compaction tests, optimum moisture content is increased and maximum dry unit weight is decreased with fiber mixing ratio. When 60mm fibrillated fiber of 0.2$\%$ mixing ratio is added to SM soil, strength increment of short-fiber reinforced soil is above 1.2 times compared to soil only. Strength increment shows maximum value for composite reinforced soil, namely, soil+short-fiber+planar reinforcement. But in case of mixing with ML soil and short-fiber, the strength of short-fiber reinforced soil is nearly the same as soil only. Internal angle of short-fiber reinforced soil is increased about $2\~3$ degrees and cohesion is also increased above 10kPa compared to soil only. Therefore, it is judged that short-fiber is a good material to strengthen the soil.

• KIEE International Transactions on Electrophysics and Applications
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• v.3C no.4
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• pp.140-145
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• 2003

The influence of microstructure nonuniformity on the electrical characteristics of ZnO varistors was analyzed with the added amount of $Al_2$O$_3$ dopants. $Al_2$O$_3$ doping can effectively inhibit grain growth. When $Al_2$O$_3$ content is in the range between 0-0.1 %, the average grain size and the standard deviation decrease quickly and the grain growth is strongly inhibited. Therefore, it is possible to increase the microstructure uniformity by accurate addition of $Al_2$O$_3$ to the ZnO varistor. The breakdown voltage increases with the decrease of standard deviation. The greater the uniformity of the Zno varistor means the higher the global breakdown voltage. The $Al_2$O$_3$ dopants having about 0-0.023 wt% content can effectively improve the voltage ratio, and the voltage ratio reaches a minimum value of 2.32 at an $Al_2$O$_3$ content of 0.005 wt%.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.10
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• pp.1380-1385
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• 2010

Buffalo meat patties with two fat levels, F1 (15% added fat) and F2 (5% added fat and 3% tapioca starch), were cooked in a pre-heated hot air oven (HO) at $175{\pm}2^{\circ}C$ for 15 min, in a microwave oven (MO) for 70 sec and by pressure cooking (PC) at 15 psi pressure for 10 min. and compared for physico-chemical, processing, sensory and microbiological quality attributes. F2 had significantly (p<0.05) higher value for the moisture and moisture protein ratio than F1. However, MO and PC patties had significantly (p<0.05) higher moisture content than HO-cooked buffalo meat patties irrespective of fat content. Highest fat percentage was in MO patties while the minimum was in PC patties. Moisture and fat retention and cooking yield were highest in MO patties irrespective of added fat content in the formulation. Cooking yield and dimensional parameters were better maintained in F2 than F1. Sensory scores viz. appearance and color, flavour, juiciness and texture for HO patties were better than other cooking methods. Sensory panelists rated overall acceptability of HO patties very good to excellent, whereas PC and MO patties were rated as good to very good irrespective of fat content. Microbiological quality was comparable in both groups irrespective of cooking methods used.

• Korean Management Science Review
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• v.34 no.1
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• pp.15-25
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• 2017

We evaluated industry growth and employment effects of every possible pairs of 22 manufacturing sectors and 16 regions (i.e, 352 region-sectors). We used annual data of manufacturing sectors from 2008 to 2014 for the evaluation. The evaluation comprises of two steps; We first find several region-sectors that outperform others with respect to the effects of industry growth and employment, which are measured by location quotient analysis, shift share method, employment to GDP ratio and employment elasticity. In addition, cross-efficiency analysis follows to classify region-sector pairs into two sub-categories : efficient region-sectors that deserve to hold the current level of investments and inefficient region-sectors where we should consider efficiency improvements. To examine the efficiency, R&D investment, employment size, and capital investment were used as input factors and production volume, added value, changes in employment size, changes in annual salary per capita were used as output factors. For region-sector pairs that have outstanding growth and employment effects but are inefficient, we employed a CCR DEA model and analyzed how much to adjust the values of input and output factors to improve the efficiency scores. The analysis results showed that inefficiency is mainly due to several factors such as R&D investment, changes in employment size and changes in annual salary per capita.

• Resources Recycling
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• v.13 no.6
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• pp.26-30
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• 2004

Input impedance of the inverted L antenna which is modified from a monopole antenna varies to very high input impedance value when the ratio of vertical height to horizontal length is reduced. So its impedance matching becomes very difficult. In this paper, we analyzed the input impedance variation range depending on the ratio of vertical height to horizontal length in the normal and ferrite thin film added configuration for the input impedance control. For the exact analysis involving the permittivity, permeability and conductivity of ferrite material, FDTD numerical method is used.

• Korean journal of food and cookery science
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• v.13 no.4
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• pp.427-433
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• 1997

Various Bam-dduk were prepared by using two kinds of chestnut flour (dried chestnut, boiled chestnut), 2 types of sugar (sugar and honey), and 3 levels of sugar (10, 20, 30 g), and they were evaluated for sensory quality, texture, moisture, and color. The addition of 10∼15% of dried chestnut flour to glutinous rice flour increased the graininess, moistness, chewiness, and sweetness of Bam-dduk, and the addition of 30∼40% boiled chestnut flour increased the graininess, moistness, and sweetness, depending up on the types and levels of sugar. The use of 10% dried chestnut flour and 30 $m\ell$ of honey gave the highest value of springiness in Bam-dduk. Gumminess, hardness and chewiness were the highest with 15％ dried chestnut flour and 20 g sugar. Cohesiveness was the strongest at 30% boiled chestnut flour and 10 $m\ell$ honey. Adhesiveness was most proper when 30 g sugar was added to 10％ dried chestnut flour. The use of boiled chestnut flour gave higher moisture content in Bam-dduk (32.2∼41.3%) than the use of dried chestnut flour (29.6∼34.2%). The values of 'L' (67.43) and 'b' (18.07) were most intensive in Bam-ddfik prepared with 15% dried chestnut and 20 g sugar, and the replacement of 20 g sugar with 30 $m\ell$ of honey gave the highest 'a' value, 2.33.

• ETRI Journal
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• v.33 no.4
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• pp.528-536
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• 2011

In this paper, we analyze the location accuracy of real-time locating systems (RTLSs) in multipath environments in which the RTLSs comply with the ISO/IEC 24730-2 international standard. To analyze the location error of RTLS in multipath environments, we consider a direct path and indirect path, in which time and phase are delayed, and also white Gaussian noise is added. The location error depends strongly on both the noise level and phase difference under a low signal-to-noise ratio (SNR) regime, but only on the noise level under a high SNR regime. The phase difference effect can be minimized by matching it to the time delay difference at a ratio of 180 degrees per 1 chip time delay (Tc). At a relatively high SNR of 10 dB, a location error of less than 3 m is expected at any phase and time delay value of an indirect signal. At a low SNR regime, the location error range increases to 8.1 m at a 0.5 Tc, and to 7.3 m at a 1.5 Tc. However, if the correlation energy is accumulated for an 8-bit period, the location error can be reduced to 3.9 m and 2.5 m, respectively.