• Analytical Science and Technology
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• v.18 no.3
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• pp.250-256
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• 2005

A selective method of high performance liquid chromatography with UV detector has been applied to determine 4 tetracycline antibiotics in the animal food, simultaneously. The targets were chlortetracycline (CTC), doxycycline (DC), oxytetracycline (OTC), and tetracycline (TC) that are used routinely in veterinary medicine for prevention and control of disease. Food samples were beef, pork, chicken, milk, whole egg, flatfish (Limanda yokohamae), jacopever (Sebastes hubbsi), seabream (Chrysophrys major), eel (Anguilla japonica) and lobster (Hommarus americanus). After extracting food samples with 20% trichloroacetic acid and McIlvaine buffer, they were purified by a $C_18$ SPE cartridge with 0.01M methanolic oxalic acid solution. The concentrated residue was re-dissolved in methanol, filtered, cleaned up and analyzed on a $C_18$ column. The mobile phase was a mixture of 0.01M oxalic acid and acetonitrile with a gradient ratio from 85:15 to 60:40. The UV wavelength was 365 nm. The overall recoveries were ranged from 71% to 98% and the limit of detections were 0.022 for CTC, 0.012 for DC and OTC and 0.009 mg/kg for TC at signal/noise > 3, respectively. As results, CTC, DC and TC were not detected in all selected food samples, however, OTC was detected in meat and fishes. The determined level of OTC was 0.04 ppm for pork, 0.17 ppm for flatfish and 0.05 and 0.08 ppm for jacopever, that were within the Maximum Residue Limits (MRLs) in the food.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.4
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• pp.938-958
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• 2024

Unsupervised Video Object Segmentation (UVOS) is a highly challenging problem in computer vision as the annotation of the target object in the testing video is unknown at all. The main difficulty is to effectively handle the complicated and changeable motion state of the target object and the confusion of similar background objects in video sequence. In this paper, we propose a novel deep Dual-stream Co-enhanced Network (DC-Net) for UVOS via bidirectional motion cues refinement and multi-level feature aggregation, which can fully take advantage of motion cues and effectively integrate different level features to produce high-quality segmentation mask. DC-Net is a dual-stream architecture where the two streams are co-enhanced by each other. One is a motion stream with a Motion-cues Refine Module (MRM), which learns from bidirectional optical flow images and produces fine-grained and complete distinctive motion saliency map, and the other is an appearance stream with a Multi-level Feature Aggregation Module (MFAM) and a Context Attention Module (CAM) which are designed to integrate the different level features effectively. Specifically, the motion saliency map obtained by the motion stream is fused with each stage of the decoder in the appearance stream to improve the segmentation, and in turn the segmentation loss in the appearance stream feeds back into the motion stream to enhance the motion refinement. Experimental results on three datasets (Davis2016, VideoSD, SegTrack-v2) demonstrate that DC-Net has achieved comparable results with some state-of-the-art methods.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.4
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• pp.1790-1806
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• 2016

Digital image encryption is widely used for image data security. JPEG standard compresses image with great performance on reducing file size. Thus, to encrypt an image in JPEG format we should keep the quality of original image and reduced size. This paper proposes a JPEG image encryption scheme based on quantized DC and non-zero AC coefficients inner category scrambling. Instead of coefficient value encryption, the address of coefficient is encrypted to get the address of cipher text. Then 8*8 blocks are shuffled. Chaotic iteration is employed to generate chaotic sequences for address scrambling and block shuffling. Analysis of simulation shows the proposed scheme is resistant to common attacks. Moreover, the proposed method keeps the file size of the encrypted image in an acceptable range compared with the plain text. To enlarge the cipher text possible space and improve the resistance to sophisticated attacks, several additional procedures are further developed. Contrast experiments verify these procedures can refine the proposed scheme and achieve significant improvements.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.196-196
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• 2013

가시광 영역에서의 높은 투과도와 낮은 전기 비저항을 갖는 ITO (Indium Tin Oxide) 박막은 현재 Display, Solar Cell, LED, Smart Phone 등 최첨단 IT산업에서 가장 많이 사용되고 있는 투명전극소재이다. IBD (Ion Beam Deposition)방법은 박막의 증착 방법 중 Plasma에서 독립적으로 이온만을 빔의 형태로 조사하여 박막을 증착하는 방법으로 기존 RF 또는 DC 스퍼터방법에 비해서 상대적으로 높은 진공도(low 10E-04 torr)와 비교적 높은 스퍼터 된 입자의 에너지를 가지는 등의 장점으로 증착 된 박막의 밀도, 거칠기가 향상되고 상대적으로 적은 결함을 가지는 박막의 제작에 사용되고 있는 기술이다. (주)인포비온에서는 IBD 기술과 더불어 표면만을 선택적으로 가열할 수 있는 EBA Technology를 사용하여 박막에 Energy를 전달하고, 이를 바탕으로 ITO 박막의 전기적, 광학적, 구조적인 특성의 변화를 관찰 연구했다 [1]. 본 연구에서는 기존의 Sputter 방법과 IBD 방법으로 증착 된 ITO 박막의 전기적, 광학적, 구조적인 특성 변화를 비교 관찰하였고, EBA 후처리로 ITO 박막을 상온에서 처리하여, 박막의 투과도, 면 저항, 미세구조의 변화를 관찰하였다. 각 특성의 변화는 UV-VIS, 4Point-Probe, TEM을 사용하여 분석하였고, 처리 전, 후의 박막의 결합에너지는 XPS로, 박막의 조성변화는 SIMS를 이용하여 각각 분석하였다.

• Restorative Dentistry and Endodontics
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• v.37 no.2
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• pp.96-103
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• 2012

Objectives: This study evaluated the effect of camphorquinone (CQ)-amine ratio on the C=C double bond conversion of resins with binary and ternary photoinitiation systems. Materials and Methods: Two monomer mixtures (37.5 Bis-GMA/37.5 Bis- EMA/25 TEGDMA) with binary systems (CQ/DMAEMA in weight ratio, group A [0.5/1.0] and B [1.0/0.5]) and four mixtures with ternary system (CQ/OPPI/DMAEMA, group C [0.1/1.0/0.1], D [0.1/1.0/ 0.2], E [0.2/1.0/0.1] and F [0.2/1.0/0.2]) were tested: 1 : 2 or 2 : 1 CQ-amine ratio in binary system, while 1 : 1 ratio was added in ternary system. The monomer mixture was cured for 5, 20, 40, and 300 sec with a Demetron 400 curing unit (Demetron). After each exposure time, degree of conversion (DC) was estimated using Fourier transform infrared (FTIR) spectrophotometer (Nicolet 520, Nicolet Instrument Corp.). The results were analyzed by ANOVA followed by Scheffe test, with p = 0.05 as the level of significance. Results: DC (%) was expressed in the order of curing time (5, 20, 40, and 300 sec). Group A ($14.63{\pm}10.42$, $25.23{\pm}6.32$, $51.62{\pm}2.69$, $68.52{\pm}2.77$); Group B ($4.04{\pm}6.23$, $16.56{\pm}3.38$, $37.95{\pm}2.79$, $64.48{\pm}1.21$); Group C ($16.87{\pm}5.72$, $55.47{\pm}2.75$, $60.83{\pm}2.07$, $68.32{\pm}3.31$); Group D ($23.77{\pm}1.64$, $61.05{\pm}1.82$, $65.13{\pm}2.09$, $71.87{\pm}1.17$); Group E ($28.66{\pm}2.92$, $56.68{\pm}1.33$, $60.66{\pm}1.17$, $68.78{\pm}1.30$); Group F ($39.74{\pm}6.31$, $61.07{\pm}2.58$, $64.22{\pm}2.29$, $69.94{\pm}2.15$). Conclusion: All the monomers with ternary photoinitiation system showed higher DC than the ones with binary system, until 40 sec. Concerning about the effect of CQ-amine ratio on the DC, group A converted into polymer more than group B in binary system. However, there was no significant difference among groups with ternary system, except group C when cured for 5 sec only.

• Food Science and Preservation
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• v.21 no.2
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• pp.193-198
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• 2014

The quality and antioxidative characteristics of drinks prepared with different mixing ratios of black garlic and Oenanthe javanica DC., BD-1 (black garlic only), BD-2 (black garlic:Oenanthe javanica DC.=2:1), BD-3 (black garlic:Oenanthe javanica DC.=1:1), and BD-4 (black garlic:Oenanthe javanica DC.=1:2), were studied. The pH increased with the increasing concentration of Oenanthe javanica DC. extract in all the tested drinks, but the sugar contents decreased. The total polyphenol contents of the drinks were 28.48 ${\mu}g/mL$ (BD-1), 41.91 ${\mu}g/mL$ (BD-2), 42.36 ${\mu}g/mL$ (BD-3), and 46.96 ${\mu}g/mL$ (BD-4). The SOD-like activity was highest for BD-4 (18.60%), followed by BD-3 (15.53%), BD-2 (12.53%), and BD-1 (10.27%). The thiobarbituric acid reactive substances (TBARS) was highest for BD-4 (52.51%), followed by BD-3 (45.70%), BD-2 (39.44%), and BD-1 (28.72%). The ferrous ion chelating activity increased with the increasing concentration of Oenanthe javanica DC extract, and BD-4 showed the best activities among all the tested drinks. The water-soluble vitamin content (vitamins B1, B2, B6, and C) of BD-4 (1197.77 ${\mu}g/mL$) was higher than those of the other drinks (BD-1, 213.02 ${\mu}g/mL$; BD-2, 477.87 ${\mu}g/mL$; BD-3, 914.72 ${\mu}g/mL$), and the vitamin C (806.21 ${\mu}g/mL$) content of the water-soluble vitamins at BD-4 was higher than those of vitamins B1 (68.04 ${\mu}g/mL$), B2 (312.51 ${\mu}g/mL$), and B6 (11.01 ${\mu}g/mL$). BD-4 showed the best score in the sensory evaluations, such as in the evaluation of the color, flavor, taste, and overall acceptability.

• Korean Journal of Materials Research
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• v.22 no.2
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• pp.61-65
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• 2012

A $Li_2O-2SiO_2$ ($LS_2$) glass was investigated as a lithium-ion conducting oxide glass, which is applicable to a fast ionic conductor even at low temperature due to its high mechanical strength and chemical stability. The $Li_2O-2SiO_2$ glass is likely to be broken into small pieces when quenched; thus, it is difficult to fabricate a specifically sized sample. The production of properly sized glass samples is necessary for device applications. In this study, we applied spark plasma sintering (SPS) to fabricate $LS_2$ glass samples which have a particular size as well as high transparency. The sintered samples, $15mm\phi{\times}2mmT$ in size, ($LS_2$-s) were produced by SPS between $480^{\circ}C$ and $500^{\circ}C$ at 45MPa for 3~5mim, after which the thermal and dielectric properties of the $LS_2$-s samples were compared with those of quenched glass ($LS_2$-q) samples. Thermal behavior, crystalline structure, and electrical conductivity of both samples were analyzed by differential scanning calorimetry (DSC), X-ray diffraction (XRD) and an impedance/gain-phase analyzer, respectively. The results showed that the $LS_2$-s had an amorphous structure, like the $LS_2$-q sample, and that both samples took on the lithium disilicate structure after the heat treatment at $800^{\circ}C$. We observed similar dielectric peaks in both of the samples between room temperature and $700^{\circ}C$. The DC activation energies of the $LS_2$-q and $LS_2$-s samples were $0.48{\pm}0.05eV$ and $0.66{\pm}0.04eV$, while the AC activation energies were $0.48{\pm}0.05eV$ and $0.68{\pm}0.04eV$, respectively.

• Analytical Science and Technology
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• v.7 no.3
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• pp.339-347
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• 1994

A multicolumn system consisted of two valve(10-port and 6-port valve)-three column (28% DC 200, SP 1700 and Chromosorb 102 column) was developed. Nine natural gas components composed of $N_2$, $CH_4$, $CO_2$, $C_2H_6$, $C_3H_8$, $i-C_4H_{10}$, $n-C_4H_{10}$, $i-C_5H_{12}$ 및 $n-C_5H_{12}$ completed all the baseline separation within 18 minutes. The accuracy and the precision of this system was tested. The retention times and the peak areas were determined with a repeatability between 0.02 and 0.16%, and less than 1%, respectively. Calibration curves for natural-gas components were plotted by the partial pressure injection method of pure gases, and good linear relationships for each component were presented. By using these calibration curves the accuracy of the multicolumn system compaired with that of the single column system for a certified standard gas of natural gas. As a result, relative error in the single and the multicolumn system was less than 0.5% and 0.04%, respectively. The result of application of this system in the analysis of importing LNG composition showed that the heating values calculated by the multicolum system were estimated lower compared with those calculated by the single column system and consequently, the importing price of LNG was able to be cut down.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.60.2-60.2
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• 2011

본 연구에서는 Indium-free 및 gallium-free 기반의 산화물 TFT를 제작하기 위해 n-type $TiO_2$ 반도체 기반의 thin film transistor ($Mo/TiO_{2-x}/SiO_2/p+\;+Si$)를 oxygen deficient black $TiO_{2-x}$ 타겟을 이용하여 DC magnetron sputtering 공법으로 제작하고 그 특성을 분석하였다. DC magnetron sputtering 공법으로 성막된 $TiO_{2-x}$ semiconductor의 전기적, 광학적, 화학적 결합 에너지 및 구조적 특성 분석을 위해 semiconductor parameter analyzer (Aglient 4156-C), UV/Vis spectrometer, X-ray Photoelectron Spectroscopy, Transmission Electron Microscopy를 각각 이용하여 분석하였으며 이를 RTA 전/후 특성 비교를 통하여 관찰하였다. $TiO_{2-x}$ TFT의 소자 특성은 RTA 열처리 전/후 전형적인 insulator 특성에서 semiconductor 특성으로 변화되는 것을 관찰할 수 있었으며, 최적화된 열처리 공정에서 filed effect mobility 0.69 $cm^2$/Vs, on to off current ratio $2.04{\times}10^7$, sub-threshold swing 2.45 V/decade와 Vth 10.45 V를 확보할 수 있었다. 또한 RTA 열처리 후 밴드갭이 3.25에서 3.41로 확장되는 특성을 나타내었다. 특히 RTA 열처리 후 stoichiometric $TiO_2$ 상태와는 다른 $Ti^{2+}$, $Ti^{3+}$, $Ti^{4+}$ 등의 다양한 oxidation states가 관찰되었으며 이러한 oxidation states를 $TiO_{2-x}$ 박막에서의 oxygen deficient 상태와 연관시킴으로써 oxygen vacancy의 n-type dopant로의 거동을 확인하였다. $TiO_2$ 채널 기반의 TFT 특성을 통하여서 indium free 또는 gallium free 산화물 채널로써의 가능성을 확인하였다.

• Korean journal of applied entomology
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• v.14 no.1 s.22
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• pp.29-33
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• 1975

The experiment It·as conducted to find out the distribution of fenitrothion in rice plants at the preheading stage and its residue in harvested grains. The results obtained were as follows; 1. Distribution of fenitrothion in rice plants were measured 15.32 ppm attached to the leaf surface immediately after spray and 6.73 ppm was penetrated into tissues after 24 hours. 2. Residual amounts of fenitrothion in rice grains was 0.04 ppm at chaff and 0.01 ppm at unpolished rice, respectively.