• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.4
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• pp.302-307
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• 2001

The underwater background noise measured in Geoje and Tongyoung diving fishing ground from May to December, 2000 and analyzed to get optimum carrier frequency and transmitter power level for underwater wireless telephone design. The results obtained are summarized as follows: 1. At the Geoje and Tongyoung diving fishing ground, the lowest ambient noise band was 25~30kHz with 57dB and 52dB re 1$\mu$Pa, respectively. 2. At the Geoje and Tongyoung diving fishing ground, the lowest noise band during fishing activity was 67dB and 62dB re 1$\mu$Pa, respectively. 3. At the Geoje diving fishing ground, the noise of water jetter which is a digging machine for subbottom shells was 102dB re 1$\mu$Pa. 4. Considering the design parameters of underwater wireless telephone, it is found that the optimum carrier frequency band is around 30kHz and the transmitter source level should be at least 131dB re 1$\mu$Pa for 500m range telephone.

• The Journal of the Convergence on Culture Technology
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• v.8 no.3
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• pp.581-587
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• 2022

The water god, Venerable Bhadra, Indian Tammola (Tamla as the 'mol' and 'ju' characters were eliminated) came to Tamla with 900 Arahants(The highest Buddhist monks) around 563-483 BC. It is the propagation of Buddhism through the world's most sacred water (Heiligkeit). The traces of the three surnames of Goyangbu are the first samsunghyeol and the dwelling of the den of Jonjaam(cave of venerable Bhadra) in Yeongsil, giving a glimpse into the era of living in caves. The second is a link that is in line with 3, the basic number in the decomposition of 900 (=3^*3^*100) disciples of Bhadra, considering that 3 and 3 of the three surnames in Goyangbu are three times 9. At this time, 3 is the person of heaven and earth, religiously, marriage, hope, or complete number, and Jeju culture is resting everywhere. For example, 3 of the samsunghyeol, 3 of the 1, 2, 3 Dodong, 3 of the 3 Dado, 3 of the 3 Mudo, 3 of the 3 disasters, 3 of the Goyangbu 3-surnames, 3 of the house Olle Jeongnang and, among 900 (=3^*3^*100) disciples of Venerable Bhadra, the common factor is 3. It is the 'island of 3'. These papers consist of 1 and 2 parts. In Part 1, the name of Tamla came from Tammola, India, and 900 Indian Buddhist Arahants estimated that the three surnames in Goyangbu were the ancestors. Part 2 highlights how the basic principle of jeonganag derived from Indian customs has evolved and is being used in modern mobile communication and DNA gene life science.

• Korean Journal of Agricultural Science
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• v.7 no.2
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• pp.145-155
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• 1980

An engineering design of the machines and equipment for processing grain as well as an understanding of processing itself need the knowledge of thermal properties of grain. Thermal properties of grain are thermal conductivity, thermal diffusivity and specific heat. Knowledge of any two and the bulk density of grain enables the third to be calculated. Several workers have investigated these properties, with special emphasis on thermal conductivity and diffusivity. However, some information is available on the specific heat of rough rice and barley but it is available only for a foreign variety of grain and for as a function of moisture content only. The objectives of this study were to develop a model for the specific heat of rough rice and barley which were a staple products in Korea as a function of initial temperature, moisture content and porosity of grain with cooling curve method, and to analyze the effect of these factors on the specific heat of rough rice and barley. The results of this study are summarized as follows; 1. The specific heat was $1.8209-2.7041kJ/kg\;^{\circ}K$ for Naked barley, 1.8862-2.5625 k.l/kg K for Covered barley, $1.5167-2.3779kJ/kg\;^{\circ}K$ for Japonica rice and $1.5260-2.3981kJ/kg\;^{\circ}K$ for Indica rice. 2. The model for the specific heat of rough rice and barley as a function of initial temperature, moisture content and porosity of grain was developed. 3. Specific heat of rough rice was decreased with initial temperature, but specific heat of barley was increased with initial temperature. 4. On the whole specific heat of sample grain was increased with moisture content of grain. 5. Specific heat of the grain was found to decrease with porosity except Indica rice.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.1
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• pp.33-46
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• 2010

We investigated and estimated at the characteristics of decomposition and by-products of N-Nitrosodimethylamine (NDMA) using a design of experiment (DOE) based on the Box-Behken design in an UV process, and also the main factors (variables) with UV intensity($X_2$) (range: $1.5{\sim}4.5\;mW/cm^2$), NDMA concentration ($X_2$) (range: 100~300 uM) and pH ($X_2$) (rang: 3~9) which consisted of 3 levels in each factor and 4 responses ($Y_1$ (% of NDMA removal), $Y_2$ (dimethylamine (DMA) reformation (uM)), $Y_3$ (dimethylformamide (DMF) reformation (uM), $Y_4$ ($NO_2$-N reformation (uM)) were set up to estimate the prediction model and the optimization conditions. The results of prediction model and optimization point using the canonical analysis in order to obtain the optimal operation conditions were $Y_1$ [% of NDMA removal] = $117+21X_1-0.3X_2-17.2X_3+{2.43X_1}^2+{0.001X_2}^2+{3.2X_3}^2-0.08X_1X_2-1.6X_1X_3-0.05X_2X_3$ ($R^2$= 96%, Adjusted $R^2$ = 88%) and 99.3% ($X_1:\;4.5\;mW/cm^2$, $X_2:\;190\;uM$, $X_3:\;3.2$), $Y_2$ [DMA conc] = $-101+18.5X_1+0.4X_2+21X_3-{3.3X_1}^2-{0.01X_2}^2-{1.5X_3}^2-0.01X_1X_2+0.07X_1X_3-0.01X_2X_3$ ($R^2$= 99.4%, 수정 $R^2$ = 95.7%) and 35.2 uM ($X_1$: 3 $mW/cm^2$, $X_2$: 220 uM, $X_3$: 6.3), $Y_3$ [DMF conc] = $-6.2+0.2X_1+0.02X_2+2X_3-0.26X_1^2-0.01X_2^2-0.2X_3^2-0.004X_1X_2+0.1X_1X_3-0.02X_2X_3$ ($R^2$= 98%, Adjusted $R^2$ = 94.4%) and 3.7 uM ($X_1:\;4.5\;$mW/cm^2$, $X_2:\;290\;uM$, $X_3:\;6.2$) and $Y_4$ [$NO_2$-N conc] = $-25+12.2X_1+0.15X_2+7.8X_3+{1.1X_1}^2+{0.001X_2}^2-{0.34X_3}^2+0.01X_1X_2+0.08X_1X_3-3.4X_2X_3$ ($R^2$= 98.5%, Adjusted $R^2$ = 95.7%) and 74.5 uM ($X_1:\;4.5\;mW/cm^2$, $X_2:\;220\;uM$, $X_3:\;3.1$). This study has demonstrated that the response surface methodology and the Box-Behnken statistical experiment design can provide statistically reliable results for decomposition and by-products of NDMA by the UV photolysis and also for determination of optimum conditions. Predictions obtained from the response functions were in good agreement with the experimental results indicating the reliability of the methodology used.