• Journal of the Korean Society for Nondestructive Testing
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• v.17 no.3
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• pp.156-161
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• 1997

The eddy current probe was designed for the test of fin tubes that have uneven outer and inner surfaces to enhance the efficiency of heat emission. Because of the surface roughness of the fin tube, it needs much care to detect flaws in the tube employing eddy current test(ECT). We made ECT probes with different coil lengths and performed eddy current test using these probes for artificially flawed specimens. By the fast Fourier transform and digital filtering, signals from these probes were processed to characterize frequency spectra. From the analysis of eddy current signals and their frequency spectra, we concluded that, for the effective testing of the tubes with the fins of 1mm pitch, 4mm coil length gave the highest S/N ratio.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.4
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• pp.436-444
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• 2016

Clamshells, which comprise more than 50% of a clam’s weight, are a major byproduct of the clam industry and are mainly composed of insoluble calcium carbonate. This study investigates the use of clamshells as a natural calcium resource. Highly soluble powdered calcium lactate (LCCL) was prepared from the calcined powdered shells of littleneck clams (LCCP) using response surface methodology (RSM) to predict optimum conditions. These conditions, as derived from pH, solubility, and yield of 11 LCCLs manufactured according to the RSM model, were 1.80 M lactic acid and 1.13 M LCCP. The actual values of pH (6.98), solubility (93.99%), and yield (351.23%) under the optimized conditions were as predicted. The derived LCCL exhibited a strong buffering capacity in the range of pH 2.78-3.90 when combined with less than 2 mL of 1 N HCl. The ranges of calcium content and solubility of LCCL were 7.7-17.5 g/100 g and 96.6-98.9%, respectively. Fourier transform infrared spectroscopy (FT-IR) of the LCCL identified it as calcium lactate pentahydrate, and field emission scanning electron microscopy (FESEM) revealed an irregular and rod-like microstructure. These results confirm the potential use of clamshells, converted to highly soluble organic acid calcium, as an additive to enhance calcium content in food ingredients.

• Korean Journal of Cognitive Science
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• v.4 no.1
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• pp.243-260
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• 1993

This paper presents an efficient method for estimationg and correcting the slant of off-line handwritten Hangul strings.In the proposed method,after extracting contours from input image.Hough tranform is applied to the contours to detect lines and estimate slants of the lines.When Hough trans form is applied to the contours,pixels which are not parts of the same stroke could be detected as a line.In order to exclude these lines from slant estimation process,detected lines which have the length less than threshold are eliminated.Experiments have been performed with address images which were extracted from live envelopes provided by Seoul Mail Center.Experimental results show that the proposed method is superior to the previous methods,which had been done with handwritten English strings.in estimation the slant of off-line handwritten Hangul strings.

• Journal of KIISE
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• v.42 no.11
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• pp.1410-1422
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• 2015

In order to design a system, software developers use an object model such as the UML class diagram. Object-Relational Transformation Methodology (ORTM) is a methodology to transform the relationships that are expressed in the object model into relational database tables, and it is applied for the implementation of the designed system. Previous ORTM studies have suggested a number of transformation methods to represent one relationship. However, there is an implementation problem that is difficult to apply because the usage criteria for each transformation method do not exist. Therefore, this paper proposes a binary decision diagram-based modeling rule for each relationship. Hence, we define the conditions for distinguishing the transformation methods. By measuring the query execution time, we also evaluate the modeling rules that are required for the verification. After evaluation, we re-define the final modeling rules which are represented by propositional logic, and show that our proposed modeling rules are useful for the implementation of the designed system through a case study.

• Journal of the Institute of Convergence Signal Processing
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• v.10 no.1
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• pp.32-39
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• 2009

In this paper, the method of region segmentation using genetic algorithm is proposed for an improvement of efficiency in moving picture coding. A genetic algorithm is the method that searches a large probing space using only a function value for a optimal combination consecutively. By progressing both motion presumption and region segmentation at once, we can assign the motion vector in a image to a small block or a pixel respectively, and transform the capacity of coding and a signal to noise rate into a problem of optimization. That is to say, there is close correlation between region segmentation and motion presumption in motion-compensated prediction coding. This is to optimize the capacity of coding and a S/N ratio. This is to arrange the motion vector in each block of picture according to the state of optimization. Therefore, we examined both the data type of genetic algorithm and the method of data processing to obtain the results of optimal region segmentation in this paper. And we confirmed the validity of a proposed method using the test pictures by means of computer simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.1C
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• pp.24-31
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• 2003

In this paper, a new opto-digital multiple information hiding and real-time extracting system is implemented. That is, multiple information is hidden in a cover image by using the stego keys which are generated by combined use of random sequence(RS) and Hadamard matrix(HM) and these hidden information is extracted in real-time by using a new optical correlator-based extraction system. In the experiment, 3 kinds of information, English alphabet of "N", "R", "L" having 512$\times$512 pixels, are formulated 8$\times$8 blocks and each of these information is multiplied with the corresponding stego keys having 64$\times$64 pixels one by one. And then, by adding these modulated data to a cover image of "Lena"having 512$\times$512 pixels, a stego image is finally generated. In this paper, as an extraction system, a new optical nonlinear joint transform correlator(NJTC) is introduced to extract the hidden data from a stego image in real-time, in which optical correlation between the stego image and each of the stego keys is performed and from these correlation outputs the hidden data can be asily exacted in real-time. Especially, it is found that the SNRs of the correlation outputs in the proposed optical NJTC-based extraction system has been improved to 7㏈ on average by comparison with those of the conventional JTC system under the condition of having a nonlinear parameter less than k=0.4. This good experimental results might suggest a possibility of implementation of an opto-digital multiple information hiding and real-time extracting system.

• Journal of the Korean Society of Tobacco Science
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• v.23 no.2
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• pp.123-132
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• 2001

In order to transform pokeweed antiviral protein cDNA to tobacco plant, total RNA was extracted from Phytolacca americana. PAP-II cDNA was synthesized from purified total RNA via RT-PCR and subcloned to recombinant vector pBluescript II SK-. 10 deletion mutant PAP-II cDNA fragments which were sequentially deleted from N-terminal by 90bp were synthesized from PAP-II cDNA except leading frame by PCR with primers designed in our laboratory. To select non-cytotoxic clone, pAc55M was constructed with yeast expression vector pAc55 and multicloning site(MCS). Sequentially deleted mutant PAP-II cDNAs were cloned on downstream of gall promoter of pAc55M. 6 non-cytotoxic deletion mutant PAP-II cDNA were selected. Selected cDNAs were cloned into plant expression vector pKGT101BH for transformation of these clones to plant through Agrobacterium tumefacience. After cloning, recombinant pKGT101BH carrying deleted mutant PAP-IIcDNA were transformed to Nicotiana tabacum cv. NC567. Transformed tobacco plants cultured on shooting and rooting media were transfered to green-house. About four weeks later, these plants were infected with physically infection using carborandum with PVY-VN strain. After 4 weeks, plants resistant to virus were selected , and seeds of these plants were gathered. Southern blot hybridization showed deleted fragments by 220bp and 420bp, so resistant ability of these plants is due to mutant PAP-II cDNA.

• Restorative Dentistry and Endodontics
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• v.39 no.3
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• pp.155-163
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• 2014

Objectives: Light-curing of resin-based materials (RBMs) increases the pulp chamber temperature, with detrimental effects on the vital pulp. This in vitro study compared the temperature rise under demineralized human tooth dentin during light-curing and the degrees of conversion (DCs) of three different RBMs using quartz tungsten halogen (QTH) and light-emitting diode (LED) units (LCUs). Materials and Methods: Demineralized and non-demineralized dentin disks were prepared from 120 extracted human mandibular molars. The temperature rise under the dentin disks (n = 12) during the light-curing of three RBMs, i.e. an Ormocer-based composite resin (Ceram. X, Dentsply DeTrey), a low-shrinkage silorane-based composite (Filtek P90, 3M ESPE), and a giomer (Beautifil II, Shofu GmbH), was measured with a K-type thermocouple wire. The DCs of the materials were investigated using Fourier transform infrared spectroscopy. Results: The temperature rise under the demineralized dentin disks was higher than that under the non-demineralized dentin disks during the polymerization of all restorative materials (p < 0.05). Filtek P90 induced higher temperature rise during polymerization than Ceram.X and Beautifil II under demineralized dentin (p < 0.05). The temperature rise under demineralized dentin during Filtek P90 polymerization exceeded the threshold value ($5.5^{\circ}C$), with no significant differences between the DCs of the test materials (p > 0.05). Conclusions: Although there were no significant differences in the DCs, the temperature rise under demineralized dentin disks for the silorane-based composite was higher than that for dimethacrylate-based restorative materials, particularly with QTH LCU.

• Electrical & Electronic Materials
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• v.10 no.8
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• pp.830-835
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• 1997

In this study an experimental investigation has been conducted to remove NOx and SO$_2$simultaneously from a combustion flue gases were consisted of NO-SO$_2$-$CO_2$-$N_2$-O$_2$([NO]o:200ppm and [SO$_2$]o:800ppm) and the injection gases used as radical source gases were NH$_3$-Ar-air and CH$_4$-Ar-air. NOx and SO$_2$removal efficiency and the other by-products were measured by Fourier Transform Infrared(FTIR) as well as SO$_2$, NOx and NO$_2$gas detectors. and SEM images after sampling. The results showed that a significant Nucleating Particle Counter(CNPC) and SEM images after sampling. The results showed that a significant aerosol particle formation was observed during a simultaneous NOx and SO$_2$removal operation in corona radical shower systems. The diameter of aerosol particles was in the range of 0.18 to 3.6${\mu}{\textrm}{m}$ with a maximum fraction of particles at particles diameter of 1${\mu}{\textrm}{m}$. The NOx removal efficiency significantly increased with increasing applied voltage and NH$_3$molecule ratio. The SO$_2$removal efficiency was not significantly effected by applied voltage and slightly increased with increasing NH$_3$molecule ratio. It could be found that it is possible to use CH$_4$for NOx and SO$_2$removal by corona radical shower systems.

• Macromolecular Research
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• v.12 no.4
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• pp.367-373
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• 2004

We have developed a rigorous heat treatment method to improve the biocompatibility of chitosan as a tissue-engineered scaffold. The chitosan scaffold was prepared by the controlled freezing and lyophilizing method using dilute acetic acid and then it was heat-treated at 110$^{\circ}C$ in vacuo for 1-3 days. To explore changes in the physicochemical properties of the heat-treated scaffold, we analyzed the degree of deacetylation by colloid titration with poly(vinyl potassium sulfate) and the structural changes were analyzed by scanning electron microscopy, Fourier transform infrared (FT-IR) spectroscopy, wide-angle X-ray diffractometry (WAXD), and lysozyme susceptibility. The degree of deacetylation of chitosan scaffolds decreased significantly from 85 to 30% as the heat treatment time increased. FT-IR spectroscopic and WAXD data indicated the formation of amide bonds between the amino groups of chitosan and acetic acids carbonyl group, and of interchain hydrogen bonding between the carbonyl groups in the C-6 residues of chitosan and the N-acetyl groups. Our rigorous heat treatment method causes the scaffold to become more susceptible to lysozyme treatment. We performed further examinations of the changes in the biocompatibility of the chitosan scaffold after rigorous heat treatment by measuring the initial cell binding capacity and cell growth rate. Human dermal fibroblasts (HDFs) adhere and spread more effectively to the heat-treated chitosan than to the untreated sample. When the cell growth of the HDFs on the film or the scaffold was analyzed by an MTT assay, we found that rigorous heat treatment stimulated cell growth by 1.5∼1.95-fold relative to that of the untreated chitosan. We conclude that the rigorous dry heat treatment process increases the biocompatibility of the chitosan scaffold by decreasing the degree of deacetylation and by increasing cell attachment and growth.