• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.28 no.3
• /
• pp.186-194
• /
• 2017

In this paper, we analyze the main performance of satellite's Synthetic Aperture Radar system for high resolution and wide swath. We have used the radiation pattern of reflector antenna with array feed and comparison between the conventional ScanSAR mode and SweepSAR mode has been carried out. The SweepSAR mode is a high-resolution wide-swath mode that transmits beams over a wide range and receives echo signals through sequential beamforming based on SCORE(SCan On REceive). In this paper, we analyzed the operating principle and characteristics of satellite's SweepSAR mode and simulate system performances. In addition, in order to increase the utilization of image, performances analysis for multiple frequency bands(C-band, X-band) has been considered.

• Journal of the Korean Society of Safety
• /
• v.31 no.5
• /
• pp.187-194
• /
• 2016

A single fire event within a fire area can cause multiple initiating events considered in internal events probabilistic safety assessment (PSA). For an example, a fire event in turbine building fire area can cause a loss of the main feed-water and loss of off-site power initiating events. This fire initiating event could result in special plant responses beyond the scope of the internal events PSA model. One approach to address a fire initiating event is to develop a specific fire event tree. However, the development of a specific fire event tree is difficult since the number of fire event trees may be several hundreds or more. Thus, internal fire events PSA model has been generally constructed by modifications of the pre-developed internal events PSA model. New accident sequence logics not covered in the internal events PSA model are separately developed to incorporate them into the fire PSA model. Recently, many fire PSA models have fire induced initiating event fault trees not shown in an internal event PSA model. Up to now, there has been no analytical comparative study on the constructions of fire events PSA model using internal events PSA model with and without fault trees of initiating events. In this study, the changing process of internal events PSA model to fire events PSA model is analytically presented and discussed.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.5 no.4
• /
• pp.329-337
• /
• 1993

It has been acknowledged as an important problem to maintain identity or compatibility among experimental laboratory data obtained separately in different wave flumes. The data quality mainly depends on how long the target waves can be realized in a flume without distortions. In the present paper a control circuit is devised in the form of multiple feed-back operations to attain a complete equality of the intended waves and the realized waves. The analysis of the circuit gives an algorithm which can be easily adapted to a small computer controlling wave making hardwares. As a main feature of the algorithm, a numerical filter with wave absorbing capability is presented. The filter is discretely realized so that the discrete input matches to the output directly, hence applicable even to nondeterministic input Through several example analyses, the algorithm proved its accuracy, being effective to both regular and irregular reflected waves.

• Computers and Concrete
• /
• v.19 no.1
• /
• pp.59-68
• /
• 2017

This study focused on modeling the behavior of the compressive stress using the average strain and ultrasonic test results in concrete. Feed-forward backpropagation artificial neural network (ANN) models were used to compare four types of concrete mixtures with varying water cement ratio (WC), ordinary concrete (ORC) and concrete with short steel fiber-reinforcement (FRC). Sixteen (16) $150mm{\times}150mm{\times}150mm$ concrete cubes were used; each contained eighteen (18) data sets. Ultrasonic test with pitch-catch configuration was conducted at each loading state to record linear and nonlinear test response with multiple step loads. Statistical Spearman's rank correlation was used to reduce the input parameters. Different types of concrete produced similar top five input parameters that had high correlation to compressive stress: average strain (${\varepsilon}$), fundamental harmonic amplitude (A1), $2^{nd}$ harmonic amplitude (A2), $3^{rd}$ harmonic amplitude (A3), and peak to peak amplitude (PPA). Twenty-eight ANN models were trained, validated and tested. A model was chosen for each WC with the highest Pearson correlation coefficient (R) in testing, and the soundness of the behavior for the input parameters in relation to the compressive stress. The ANN model showed increasing WC produced delayed response to stress at initial stages, abruptly responding after 40%. This was due to the presence of more voids for high water cement ratio that activated Contact Acoustic Nonlinearity (CAN) at the latter stage of the loading path. FRC showed slow response to stress than ORC, indicating the resistance of short steel fiber that delayed stress increase against the loading path.

• Asian-Australasian Journal of Animal Sciences
• /
• v.28 no.11
• /
• pp.1624-1628
• /
• 2015

Rigorously standardized laboratory protocols are essential for meaningful comparison of data from multiple sites. Considering that interactions of minerals with organic matrices may vary depending on the material nature, there could be peculiar demands for each material with respect to digestion procedure. Acid digestion procedures were evaluated using different nitric to perchloric acid ratios and one- or two-step digestion to estimate the concentration of calcium, phosphorus, magnesium, and zinc in samples of carcass, bone, excreta, concentrate, forage, and feces. Six procedures were evaluated: ratio of nitric to perchloric acid at 2:1, 3:1, and 4:1 v/v in a one- or two-step digestion. There were no direct or interaction effects (p>0.01) of nitric to perchloric acid ratio or number of digestion steps on magnesium and zinc contents. Calcium and phosphorus contents presented a significant (p<0.01) interaction between sample type and nitric to perchloric acid ratio. Digestion solution of 2:1 v/v provided greater (p<0.01) recovery of calcium and phosphorus from bone samples than 3:1 and 4:1 v/v ratio. Different acid ratios did not affect (p>0.01) calcium or phosphorus contents in carcass, excreta, concentrate, forage, and feces. Number of digestion steps did not affect mineral content (p>0.01). Estimated concentration of calcium, phosphorus, magnesium, and zinc in carcass, excreta, concentrated, forage, and feces samples can be performed using digestion solution of nitric to perchloric acid 4:1 v/v in a one-step digestion. However, samples of bones demand a stronger digestion solution to analyze the mineral contents, which is represented by an increased proportion of perchloric acid, being recommended a digestion solution of nitric to perchloric acid 2:1 v/v in a one-step digestion.

• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.11
• /
• pp.1555-1565
• /
• 2009

Anaerobic rumen fungi have been regarded as good genetic resources for enzyme production which might be useful for feed supplements, bio-energy production, bio-remediation and other industrial purposes. In this study, an expressed sequence tag (EST) library of the rumen anaerobic fungus Neocallimastix frontalis was constructed and functional genes from the EST library were analyzed to elucidate carbohydrate metabolism of anaerobic fungi. From 10,080 acquired clones, 9,569 clones with average size of 628 bp were selected for analysis. After the assembling process, 1,410 contigs were assembled and 1,369 sequences remained as singletons. 1,192 sequences were matched with proteins in the public data base with known function and 693 of them were matched with proteins isolated from fungi. One hundred and fifty four sequences were classified as genes related with biological process and 328 sequences were classified as genes related with cellular components. Most of the enzymes in the pathway of glucose metabolism were successfully isolated via construction of 10,080 ESTs. Four kinds of hemi-cellulase were isolated such as mannanase, xylose isomerase, xylan esterase, and xylanase. Five $\beta$-glucosidases with at least three different conserved domain structures were isolated. Ten cellulases with at least five different conserved domain structures were isolated. This is the first solid data supporting the expression of a multiple enzyme system in the fungus N. frontalis for polysaccharide hydrolysis.

• Journal of Microbiology and Biotechnology
• /
• v.23 no.8
• /
• pp.1176-1184
• /
• 2013

Anti-hepatocyte growth factor (anti-HGF) monoclonal antibodies (mAbs) are potential therapeutics against various cancers. Screening for high-producer clones is a time-consuming and complex process and is a major hurdle in the development of therapeutic mAbs. Here, we describe an efficient approach that allows the selection of high-producer Chinese hamster ovary (CHO) cell lines producing the novel anti-HGF mAb SFN68, which was generated previously by immunizing HGF bound to its receptor c-Met. We selected an SFN68-producing parental cell line via transfection of the dihydrofolate reductase-deficient CHO cell line DG44, which was preadapted to serum-free suspension culture, with an SFN68-expression vector. Subsequent gene amplification via multiple passages of the parental cell line in a methotrexate-containing medium over 4 weeks, followed by clonal isolation, enabled us to isolate two cell lines, 2F7 and 2H4, with 3-fold higher specific productivity. We also screened 72 different media formulated with diverse feed and basal media to develop a suboptimized medium. In the established suboptimized medium, the highest anti-HGF mAb yields of the 2F7 and 2H4 clones were 842 and 861 mg/l, respectively, which were about 10.5-fold higher than that of the parental cell line in a non-optimized basal medium. The selected CHO cell lines secreting high titers of SFN68 would be useful for the production of sufficient amounts of antibodies for efficacy evaluation in preclinical and early clinical studies.

• Environmental Engineering Research
• /
• v.13 no.1
• /
• pp.19-27
• /
• 2008

Simultaneous removal of ternary gases of $NH_3$, $H_2S$ and toluene in a contaminated air stream was investigated over 180 days in a biofilter. A commercially available inorganic/polymeric composite chip with a large void volume (bed porosity > 0.80) was used as a microbial support. Multiple microorganisms including Nitrosomonas and Nitrobactor for nitrogen removal, Thiobacillus thioparus (ATCC 23645) for $H_2S$ removal and Pseudomonas aeruginosa (ATCC 15692), Pseudomonas putida (ATCC 17484) and Pseudomonas putida (ATCC 23973) for toluene removal were used simultaneously. The empty bed residence time (EBRT) ranged from 60 - 120 seconds and the inlet feed concentration was $0.0325\;g/m^3-0.0651\;g/m^3$ for $NH_3$, $0.0636\;g/m^3-0.141\;g/m^3$ for $H_2S$, and $0.0918\;g/m^3-0.383\;g/m^3$ for toluene, respectively. The observed removal efficiency was 2% - 98% for $NH_3$, 2% - 100% for $H^2S$, and 2% - 80% for toluene, respectively. Maximum elimination capacity was about $2.7\;g/m^3$/hr for $NH_3$, > $6.4\;g/m^3$/hr for $H_2S$ and $4.0\;g/m^3$/hr for toluene, respectively. The inorganic/polymeric composite carrier required 40 - 80 days of wetting time for biofilm formation due to the hydrophobic nature of the carrier. Once the surface of the carrier was completely wetted, the microbial activity became stable. During the long-term operation, pressure drop was negligible because the void volume of the carrier was two times higher than the conventional packing materials.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.51 no.4
• /
• pp.49-58
• /
• 2014

A low-swing differential near-ground signaling (NGS) transceiver for low-power high-speed mobile I/O interface is presented. The proposed transmitter adopts an on-chip regulated programmable-swing voltage-mode driver and a pre-driver with asymmetric rising/falling time. The proposed receiver utilizes a new multiple gain-path differential amplifier with feed-forward capacitors that boost high-frequency gain. Also, the receiver incorporates a new adaptive bias generator to compensate the input common-mode variation due to the variable output swing of the transmitter and to minimize the current mismatch of the receiver's input stage amplifier. The use of the new simple and effective impedance matching techniques applied in the transmitter and receiver results in good signal integrity and high power efficiency. The proposed transceiver designed in a 65-nm CMOS technology achieves a data rate of 13 Gbps/channel and 0.3 pJ/bit (= 0.3 mW/Gbps) high power efficiency over a 10 cm FR4 printed circuit board.

• Asian-Australasian Journal of Animal Sciences
• /
• v.12 no.7
• /
• pp.1085-1089
• /
• 1999

Energy requirement of Rhode Island Red (RIR) hens was studied by comparative slaughter technique. Seventeen hens above 72 weeks of age were slaughtered in batches. Batch I consisted of 5 hens which were slaughtered initially. Batch II comprised of six hens, which were fed ad libitum broken rice (BR)-based diet for 18 days. Record of feed intake, number of eggs laid and egg weight during the period was kept. These hens were slaughtered and body energy content was determined. Egg energy was consisted as energy deposited. Batch III consisting of six hens which were fed varying quantity of diet for 15 days, were slaughtered similarly as hens of batch II. Regression equation (body weight to body energy) developed on batch I was applied to batch II and developed on batch II was applied to batch III hens, to find out initial body energy content of hens. Egg energy (EE) was calculated according to formula: EE (kcal) = -19.7 + 1.81 egg weight (g). Regressing metabolisable energy (ME) intake on energy balance (body energy change + egg energy), maintenance ME requirement of hens was found to be $119.8kcal/kg\;W^{0.75}/d$. Multiple regression of ME required for production on energy retained as protein and fat (body plus egg energy) indicated that RIR hens synthesize proteins with an efficiency of 85.5 and fat with an efficiency exceeding 100 percent on BR based diet.