• 융합신호처리학회논문지
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• 제11권2호
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• pp.97-103
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• 2010

본 논문에서는 새로운 디지털 워터마킹 기법을 제안하였다. 제안한 알고리즘은 임의의 실수가 2의 지수형식의 합으로 될 수 있고, 몇 개의 수로써 표현될 수 있음을 이용하였다. 여기서, 임의의 실수가 일부분 변하더라도 2의 지수형식으로 표현하였을 경우에 큰 자리 수는 변하지 않음을 알 수 있다. 제안한 알고리즘은 입력 영상을 웨이블렛 변환하였고, 2의 지수형식으로 표현된 웨이블렛의 중요계수에 다중 바코드 워터마크를 삽입하였다. 제안한 알고리즘은 세미 블라인드이고, 객관적이면서 주관적인 워터마크 검출을 할 수 있다. 또한 병함기법을 이용함으로써 좀 더 정확한 워터마크를 추출할 수 있었다. 실험결과에서 제안한 알고리즘은 잡음 및 영상압축 공격에 대하여 향상된 결과를 보였다.

• Nuclear Engineering and Technology
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• 제54권4호
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• pp.1206-1212
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• 2022

Cold-crucible induction melting (CCIM) technology has been intensively studied as an advanced vitrification process for the immobilization of highly radioactive waste. This technology uses high-frequency induction to melt a glass matrix and waste, while the outer surface of the crucible is water-cooled, resulting in the formation of a frozen glass layer (skull). In this study, for the fabrication of borosilicate glass waste form, CCIM operation test with 60 kg of glass per batch was conducted using surrogate wastes composed of Cs, Sr, and Nd as a representative of highly radioactive nuclides generated during spent nuclear fuel management. A 60 kg-scale glass waste form was successfully fabricated through melting and draining processes using a CCIM system, and its physicochemical properties were analyzed. In particular, to enhance the controllability and reliability of the draining process, an air-cooling drain control method that can control draining through air-cooling near drain holes was developed, and its validity for draining control was verified. The method can offer controllability on various draining processes, such as molten salt or molten metal draining processes, and can be applied to a process requiring high throughput draining.

• 수산해양교육연구
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• 제27권5호
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• pp.1457-1469
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• 2015

원료멸치에 식염첨가량을 달리하여 $15^{\circ}C$로 설정된 incubator에서 110일간 숙성 중 멸치육젓의 이화학적 및 관능적 특성에 대하여 조사한 결과를 요약하면 다음과 같다. $15^{\circ}C$에서 식염 15, 20 및 25%를 각각 첨가하여 숙성 시킨 멸치육젓의 경우 숙성기간이 길어짐에 따라 수분 함량이 점점 감소하였으며, 조회분 함량은 증가하였고, 조단백질 및 조지방 함량은 거의 변화가 없었다. 그리고 식염첨가량이 많은 시료일수록 수분함량은 감소하였고, 조지방 및 조회분은 증가하였으며, 조단백질 및 pH는 식염첨가량에 따른 차이가 거의 없었다. 숙성기간이 길어질수록 TBA값, 아미노질소 함량, 염도 및 조직감은 그 값이 증가하였으며, 색도는 L값 및 b값은 감소하였으나 a값 및 ${\Delta}E$값은 증가하였다. 식염첨가량이 증가할수록 염도 및 조직감은 증가하였으나 TBA값 및 아미노질소 함량은 감소하였으며, 색도의 경우 적색도(a값)와 황색도(b값)는 증가하였으며, 명도(L값) 및 색차(${\Delta}E$값)는 큰 차이가 없었다. 총유리아미노산 함량은 110일 숙성 시킨 시료의 경우 식염 15%를 첨가한 시료가 가장 많은 함량이었으며, 그 다음으로 식염 20%를 첨가한 시료, 식염 25%를 첨가한 시료의 순이었다. 식염 15-25%를 첨가한 시료 모두 lysine, leucine 및 histidine이 주요아미노산이었다. 관능검사 결과 15, 20 및 25%를 첨가한 시료 모두 숙성 80일 이후 관능적 기호도가 3.0이상으로 좋아짐을 알 수 있었다. 색의 경우 15, 20 및 25%를 첨가한 시료는 차이가 거의 없었으며, 조직감의 경우 식염 25%를 첨가한 시료가 가장 선호도가 좋았고, 그 다음이 20%를 첨가한 시료, 15%를 첨가한 시료의 순이었다. 반면 냄새, 맛 및 종합평가의 경우 식염 15%를 첨가한 시료가 가장 선호도가 좋았고, 그 다음이 20%를 첨가한 시료, 25%를 첨가한 시료의 순으로 나타나 염도가 낮은 시료일수록 관능적 기호도가 좋은 것으로 판단되었다.

• 한국축산식품학회지
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• 제29권5호
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• pp.590-598
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• 2009

The aim of this study was to model and optimize the calcium alginate (CA) and microbial transglutaminase (TG) systems to form a cold-set myofibrillar protein (MP) gel containing 0.1 M or 0.3 M NaCl using a response surface methodology. The gel strengths of cold-set and heat-induced MP gels, and cooking yields were measured. All measured parameters showed determination coefficients ($R^2$) above 0.7 without a lack-of-fit. The CA system had the best results with component ratios of 1.0:0.3:1.0 corresponding to sodium alginate, calcium carbonate and glucono-$\delta$-lactone, respectively, and was favourable at 0.1 M NaCl. In contrast, the TG system only had an effect on cold-set MP gelation at 0.3 M salt, and the optimal ratio of TG to sodium caseinate was 0.6:0.5. By combining the two systems at 0.3 M NaCl, an acceptable cold-set MP gel with an improved texture and high cooking yield could be formed. Therefore, these results indicated that the functionality of the cold-set MP gel could be enhanced by combining these two optimized gelling system.

• 한국해양공학회지
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• 제15권4호
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• pp.28-37
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• 2001

The water quality in Yongil Bay is getting worse due to the sewage and the waste water from the surrounding industrial complex. The study aims to simulate the current system that is necessary to build ecosystem model for the optium water quality control and clarify the correlation of current system characteristics with water quality in Yongil Bay. To clarify the characteristics of coastal water movement system and verify the applicability of the 3-D model, the current system was simulated using 3-D model baroclinic model which considers tidal current and density effects. As the results of numerical experiments, it is proved the 3-D model is the most applicable on appearing the current system of the stratificated Yongil Bay difference of density. Form the results of simulation considered tidal current only, it can be clarified that the water body flows in the inner bay through the bottom layer and flows out the outer bay through the surface layer in Yongil Bay. And the fresh water from the Hyongsan river and the thermal discharge form POSCO have a little effect on the current system in Yongil Bay, but the diffusion of heat and salt has an important effect upon the formation of the density stratification of the water quality distribution is closely related with the current structure characteristics as well as the tidal residual current system in Yongil Bay.

• 복식문화연구
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• 제12권6호
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• pp.999-1009
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• 2004

Chitin is a derived product from the shell of shrimp or crab. Chitosan, a deacetylated product of chitin, has widely been used in the biomedical sector, food industry, and textile industry. Chitosan exhibits fiber-forming property under certain conditions. Nonwoven fabrics made of chitosan fibers may have diverse applications in the industry. Previous studies have revealed that the dye uptake properties of natural dyestuffs improved by the chitosan pretreatment on the fabric specimens. In this case, fabric specimen is coated with acidic salt form of chitosan, which is different from the pure chitosan, since the coating process employes coating with the acidic solution of the chitosan and subesquent drying. In this study, chitosan nonwoven fabric samples were prepared from chitosan sample having deacetylation degree of $100\%$ and molecular weight of 650,000. Chitosan nonwoven fabrics maintain the form of $-NH_2$ end-group. These in turn exhibit higher dye uptake ability than the fabrics coated with chitosan acidic solutions do.

• 방사성폐기물학회지
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• 제19권2호
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• pp.233-241
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• 2021

A series of three bench-scale experiments was performed to investigate the conversion of sodium metal to sodium chloride via reactions with non-metal and metal chlorides. Specifically, batches of molten sodium metal were separately contacted with ammonium chloride and ferrous chloride to form sodium chloride in both cases along with iron in the latter case. Additional ferrous chloride was added to two of the three batches to form low melting point consolidated mixtures of sodium chloride and ferrous chloride, whereas consolidation of a sodium-chloride product was performed in a separate batch. Samples of the products were characterized via X-ray diffraction to identify attendant compounds. The reaction of sodium metal with metered ammonium chloride particulate feeds proceeded without reaction excursions and produced pure colorless sodium chloride. The reaction of sodium metal with ferrous chloride yielded occasional reaction excursions as evidenced by temperature spikes and fuming ferrous chloride, producing a dark salt-metal mixture. This investigation into a method for controlled conversion of sodium metal to sodium chloride is particularly applicable to sodium containing elevated levels of radioactivity-including bond sodium from nuclear fuels-in remote-handled inert-atmosphere environments.

• 한국표면공학회지
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• 제51권6호
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• pp.354-359
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• 2018

NaCl-induced hot corrosion behavior of ASTM T22 (Fe-2.25Cr-1Mo), T91 (Fe-9Cr-1Mo), T92 (Fe-9Cr-1.8W-0.5Mo), 347HFG (Fe-18-Cr-11Ni), and 310H (Fe-25Cr-19Ni) steels was studied after spraying NaCl on the surface. During corrosion at $600-800^{\circ}C$ for 50-100 h, thick, non-adherent, fragile, somewhat porous oxide scales formed. All the alloys corroded fast with large weight gains owing to fast scaling and destruction of protective oxide scales. Corrosion rates increased progressively as the corrosion temperature and time increased. Corrosion resistance increased in the order of T22, T91, T92, 347HFG, and 310H, suggesting that the alloying elements of Cr, Ni, and W beneficially improved the corrosion resistance of steels. Basically, Fe oxidized to $Fe_2O_3$, and Cr oxidized to $Cr_2O_3$, some of which further reacted with FeO to form $FeCr_2O_4$ or with NiO to form $NiCr_2O_4$.

• 생명과학회지
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• 제18권8호
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• pp.1164-1168
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• 2008

염분 스트레스에 노출된 옥수수(Zea mays) 유식물의 원뿌리는 길이생장이 억제되는데, 본 연구에서는 위와 같은 조건에서 뿌리의 굴중성 반응을 조사하였다. 고농도의 NaCl과 KCl에 의해 스트레스를 받은 옥수수 원뿌리는 수평 상태에서 중력 자극을 받기 시작한 지 2시간 이후부터 대조구에 비하여 현저한 굴중성 반응을 나타내었다. 이러한 굴중성 촉진 현상은 $Na^{+}$가 아니라 $K^{+}$에 의한 것이었으며, Cl-도 굴중성 반응 촉진에 기여하였다. 이로부터 이들 $K^{+}$와 $Cl^{-}$이온들이 세포 팽창에 필요한 삼투 조절자로 기능한다는 결론을 얻었다. 또한 염분 스트레스에 의하여 뿌리의 길이 생장이 억제되더라도 중력장 내에서의 위치 결정은 억제되지 않고 오히려 촉진된다는 점도 확인하였다.

• 대한화학회지
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• 제4권1호
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• pp.15-17
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• 1957

1. Preparation of Titanium tetrachloride; The following precesses were strictly followed as the preliminary step to obtain pure $TiOCl_2$, titanyl chloride; First, pure Titanium Oxide mixed with carbon is rolled into pills. After drying up perfectly, these pills are heated at 900∼1000${\circ}C$. And then the pills are subjected to the flow of $Cl_2$ gas in a quartz tube heated to 900-1000${\circ}C$. Thus Titanium tetrachloride is obtained. 2. Preparation of $TiOCl_2$ ; Yellowish trobrown solution is made by pouring 80 g of conc. HCl (sp.gr. 1.19) to 45 gr of Titanium tetrachloride (approx. 2 times of theoretical amount). Then this solution is kept settled for 5-days in a desiccator filled with phosphorous pentoxide at room temperature. As the colorless amorphous solid thus obtained is washed with aceton, 36.5 g of the pure salt are obtained. 3. Determination of composition. The analysis of the sample taken from the deposit desiccated gives the following data; (A) Qualitative analysis; a) $Ti(OH)_4$ is precipitated by adding NaOH in water solution of the salt. b) Adding $AgNO_3$ solution, the water solution of the salt gives white precipitate of AgCl. c) When acid and $H_2O_2$ are added, the solution turns its color to redish brown (This proves that $TiO^{++}$ was converted into $TiO^{++}$ by oxidation of $H_2O_2$. (B) Quantitative analysis; a) $Ti(OH)_4$ precipitated by $10{\%}$ NaOH isalitatsubjected consecutively to the filtration and ignition in porcelain crucible at approx. 1000${\circ}C$. , then $TiO_2$ thus formed is weighed and calculated into Ti content. b) Chlorine involved in water solution of the salt is determined by Vorhardt method. Result: The values obtained from previous analysis, devied by their atomic weight gives the following composition: Ti : Cl = 1 : 2 Therefore $TiOCl_2$ should be given as its molecular formula. 4. Summary. When $TiCl_4$ is additated into conc. HCl, $TiO^{++}$ formed exists as a stable form, and forms $TiOCl_2$. However $TiOCl_2$ is unstable to heating. When the temperature is raised to $65{\circ}C$the decomposition of the solution is accelerated, and gives $TiO_2$ aq. $TiOCl_2$ in addition is highly hygroscopic.