• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.10
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• pp.1427-1435
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• 2010

A mixed finite element model was developed using the classical plate theory to analyze the nonlinear bending of a plate. The appropriate weight functions for the constraints integrated over the domain were determined by the Lagrange multiplier method by using the principle of minimum virtual energy; which provides the constitutive relations between force-like variables and strains. All of detail terms of element wise coefficient matrices and associate tangent matrices to be used in the Newton iterative method are presented. Then, the linear solutions of the current model and those of the traditional displacement model under the SS (simple support) boundary conditions were compared with the existing analytical solution. The post-processed images of the nonlinear results of the force-like variables are presented to show the continuity of the solutions at the joint of the element boundaries. Finally, the converged nonlinear finite element solutions of the current model are compared with those of existing traditional displacement model.

• Journal of Nutrition and Health
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• v.49 no.2
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• pp.88-98
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• 2016

Purpose: We recruited 118 women in their early 20's to examine the relationship between sodium intake and salty taste thresholds and preference. We also examined the association of salty taste preference with sodium-related dietary behaviors and major dishes contributing to sodium intake. Methods: Daily sodium intake was estimated using a 127-item dish-frequency questionnaire. Salty taste thresholds and preference were measured using rating scales using water solution of NaCl and a self-administered questionnaire based on a Likert scale, respectively. Results: Salty taste preference showed positive correlation with daily sodium intake and sodium intake-increasing behaviors, and inverse association with sodium intake-decreasing behaviors, including salt and soy sauce use at the table, the frequency of eating out and home delivery of foods, broth consumption of soup, stew or noodle soup, the use of ready-to-serve or processed foods, fresh vegetable intake, and the accommodating attitude toward bland food. Intake of sodium-contributing dishes, including ramen, spicy soft-tofu stew, radish kimchi, and dishes containing kimchi, also showed positive association with salty taste preference. Unexpectedly, detection and recognition thresholds of salty taste showed no association with salty taste preference, sodium intake, and sodium-related dietary behaviors. Conclusion: These findings suggest that salty taste preference could reflect sodium intake of individuals rather than thresholds of saltiness, and may be used as a simple and effective proxy for usual sodium intake.

• Journal of the Korean Society for information Management
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• v.19 no.4
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• pp.96-111
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• 2002

A lot of accumulated data of many quantity exist within a institution or an organization, but most data is remained in form of standardization as each institution or organization. There are difficulty in exchange and share of information. New concept of knowledge information resource management to overcome this disadvantage was introduced, and the digitization of knowledge information resources to share and manage accumulated data is been doing. Specially, in science technic or education scholarship it, the tendency that importing XML to process necessary data to exchange and share of knowledge information resources structurally, and limitation of back for search and indexing or reusability is happened according as expression of great many mathematics used inside electron document of these sphere is processed to nonstructural data of image or text and so on. There is interest converged in processing of mathematics that use MathML to overcome this, and we require the solution to be able to process MathML easily and efficiently on structural document. In this paper, designed and implemented of XML document editing system which easy structural process of electronic document for knowledge information resources, and create and express MathML easily on structural document without expert knowledge about MathML.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.1
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• pp.7-15
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• 2004

The ferroelectric SBT thin films as a material of capacitors for non-volatile FRAMs have some problems that its remanent polarization value is relatively low and the crystallization temperature is quite high abovc 80$0^{\circ}C$. Therefore, in this paper, SBTN solution with S $r_{0.9}$B $i_{2.1}$T $a_{1.8}$N $b_{0.2}$$O_{9}$ composition was synthesized by sol-gel method. Sr(O $C_2$ $H_{5}$)$_2$, Bi(TMHD)$_3$, Ta(O $C_2$ $H_{5}$)$_{5}$and Nb(O $C_2$ $H_{5}$)$_{5}$ were used as precursors, which were dissolved in 2-methoxyethanol. SBTN thin films with 200 nm thickness were deposited on Pt/Ti $O_2$/ $SiO_2$/Si substrates by spin-coating. UV-irradiation in a power of 200 W for 10 min and rapid thermal annealing in a 5-Torr-oxygen ambient at 76$0^{\circ}C$ for 60 sec were used to promote crystallization. The films were well crystallized and fine-grained after annealing at $650^{\circ}C$ in oxygen ambient. The electrical characteristics of 2Pr=11.94 $\mu$C/$\textrm{cm}^2$, Ps＋/Pr＋=0.54 at the applied voltage of 5 V were obtained for a 200-nm-thick SBTN films. This results show that 2Pr values of the UV irradiated and rapid thermal annealed SBTN thin films at the applied voltage of 5 V were about 57% higher than those of no additional processed SBTN thin films. thin films.lms.s.s.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.1
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• pp.42-49
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• 1988

In order to utilize sea mustard, Undaria pinnatifida, effectively. sea mustard jam was prepared by use of physical properties of polysaccharides, mainly alginic acid and then its chemical composition, nutritive qualifies and the stability of pigments were examined. Suitable processing condition for sea mustard jam was as fellows : as the first stage, fresh sea mustard was scalded for 20 sec at $85^{\circ}C$ and dried sea mustard was dipped for 20 min in cold water for rehydration, then both sea mustards were treated by draining and chopping. Next, after adding 4 fold of $0.5\%\;K_2HPO_4$ solution to weight of chopped sea mustards, the mixed solutions were agitated for 15 min at $95^{\circ}C$, and gelated sea mustards were filterated by pressing. Flow characteristics of those sea mustard jam were regarded mixed type having pseudoplastic type and yield stress. Judging from sensory evaluation, adding $0.375\%$ of saccharin, $2\%$ of sorbitol, $0.25\%$ of citric acid and $0.5\%$ of powder of roasted soybean to sea mustard jam were suitable for enhancing taste and flavor of product. Chemical composition of products were scarcely changed throughtout processing. Jam processed by fresh sea mustard was better than dried one in contents of chlorophyll and total carotenoid pigments. In fatty acid composition, polyenoic acids of $C_{18:3},\;C_{20:4},\;C_{20:5},\;C_{22:6}$ were held high contents as known to have lowering function of cholesterol contents. It was presumed that dominant contents in free amino acids such as lysine, alanine, glutamic acid and organic acids such as citric acid, oxalic acid, $\alpha-ketoglutaric$ acid, lactic acid and succinic acid held important role for the flavor of sea mustard jam.

• The korean journal of orthodontics
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• v.25 no.3 s.50
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• pp.341-353
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• 1995

Previous study had shown the diversities in the propriety for optimal bond strength on the concentration of the etchant. The aim of present study in vitro was to evaluate and compare the shear bond strength of orthodontic brackets to enamel and to measure the depth of etch on the phosphoric acid concentrations. A hundred and seventy six extracted bovine lower centrals were ground to yield flat surfaces and etched by the concentration $0%,\;5%,\;10%,\;20%,\;30%,\;40%,\;50%,\;60%,\;70%,\;80%\;and\;85\%$ of phosphoric acid respectively during 60 seconds. The shear bond strength of orthodontic brackets, the depth of etch and surface roughness of the enamel were measured, and scanning electron microscopic observations on the etched enamel surfaces were carried out. The data obtained from the very experiments were processed and statistically analyzed and evaluated. The gradual increase in the depth of etch to enamel as the accretion of the concentration of the phosphoric acid upto $40-50\%$ and decline henceforth were manifested. The surface roughness showed no correlation with the depth of etch, yet moderate correlation with the shear bond strength of brackets. Scanning electron microscopic investigation revealed that morphological patterns of the etched enamel surfaces for $5\%\;to\;40\%$ of concentrations were even and homogenous, and those for $50\%$ as well as $60\%$ exhibited the overetched and unhomogenous. The shear bond strengths kom $10\%\;to\;60\%$ of concentration showed no statistically significant differences. It was suggested that the shear bond strengths at $5\%\;and\;70\%$ were sufficient to tolerate the force levels of the ordinary orthodontic treatment notwithstanding to be significantly lower than those from $10\%\;to\;60\%$ phosphoric acid solution.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.4
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• pp.344-355
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• 2004

Statement of problem: For a long time, many of denture base acrylic resins have been used for edentulous and partial edentulous patients because of easy manipulation and good mechanical properties, but its esthetic aspect has not been commented enough. Denture base acrylic resins also has caused esthetic problems due to discoloration or staining as in esthetic restoration. Many researches and reports have treated the problems and accomplished esthetic improvement. But these researches and reports dealt with general food colors or beverages, not with fermented foods. Purpose: This study is designed to assess what fermented foods, such as soy sauce, gochujang, and toenjang that many of Koreans have taken in, influence on the color and hardness variation of denture base acrylic resins. Materials and methods: For the procedure, twelve disks per 4 denture base acrylic resins were fabricated with a thickness of 2mm and 16mm in diameter. Each seven specimen were measured for discoloration with spectrophotometer, while the others, five specimen, for surface hardness change with Barcol hardness tester, over time. Each 12 specimen were immersed into the 4 beakers of fermented foods(soy sauces, gochujangs, toenjangs, deionized water), and $L^{*},a^{*}$, and $b^*$ values were measured for the color difference$({\Delta}E^*)$, on the 1st, 7th, and 28th day with spectrophotometer, with the measurement of surface hardness change. Each data observed was processed statistically. Results: The findings are as follows; Discoloration 1. All of denture base resins was not influenced by the kind of fermented foods, except for $QC20^{(R)}$ 2. Soy sauce and red pepper paste caused more change for denture base resins than deionized water and soy bean paste, except for Perform$^{(R)}$ 3. Most significant change was shown in Lucitone 199$^{(R)}$, whereas Perform$^{(R)}$ results in the least change for all immersed solution, with no statistical significance. Hardness change 1. Barcol hardness values in deposited specimens have been changed low degree, but with significant statistical change according to the kind of food and duration. 2. Lucitone$^{(R)}$ 199 as significantly lower Barcol hardness value than others do. Conclusion: Based on the above results, it suggests that the habitual intake of fermented foods is not helpful for the color stability of denture base acrylic resins because Soy sauce and red pepper paste mainly caused discoloration and surface hardness change. Particularly $Lucitone199^{(R)}$ shows specific discoloration and low surface hardness values. Therefore, it is recommended giving caution patients with denture of $Lucitone199^{(R)}$ especially against the habitual intake of fermented foods like soy sauce and red pepper paste.

• Journal of the Korean Electrochemical Society
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• v.10 no.3
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• pp.184-189
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• 2007

The importance of secondary battery industry is getting excited according to the development of battery industry as a high efficiency energy supplier of electronic machine of mobile information such as mobile phone, lap-top computer, PDA. It is rasing the interest about security of safety and high efficiency of cathode material for main part of secondary lithium battery. The cathode material which has been used like $LiCoO_2,\;LiMn_2O_4,\;LiNi_xCo_yMn_zO_2,\;LiNi_xCo_yM_zO_2$ (M=Al, Zr, Mg etc.,) the most typical material is $LiCoO_2$. But it is studying the development of substitute such as efficiency amelioration of $LiCoO_2$, thetiary element, olivine element because of the capacity of $LiCoO_2$, the matter of security; especially the betterment of efficiency, security research of safety has been actively processed in domestic and overseas about surface coating treatment of active cathode which is using oxide ($M_xO_3$). This study analyses side effect of battery according to increase of surface treatment, formation of precipitation for reagent condensation, non-reagent residue of oxide ($M_xO_3$) which is remains during the surface treatment of $LiCoO_2$; conducts study of new process, the consideration of the electrochemical property to improve oxide solution of mixing rate, mixture of surface treatment, dryness, calcinations conditionetc.

• Applied Chemistry for Engineering
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• v.26 no.6
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• pp.640-647
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• 2015

As the need for next-generation flexible electronics grows, novel materials and technologies that can replace conventional indium tin oxide (ITO) for transparent electrodes have been of great interest. Among them, a conducting polymer, especially poly(3,4-ethylenedioxythiophene) : poly(styrene sulfonate) (PEDOT : PSS) is one of the most promising candidates because it is mechanically flexible, inexpensive, and capable of being processed in solution. Currently, there are a lot of research efforts on enhancing its electrical conductivity to the level of ITO or metal electrodes through chemical and/or physical processing. In this review article, we present various additives and pre-/post-deposition processing methods for improving the electrical conductivity of PEDOT : PSS. Some of representative reports are also introduced, which demonstrated the use of conductivity-enhanced PEDOT : PSS as transparent electrodes in electronics and energy conversion.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.348-348
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• 2014

차세대 디스플레이 구동 회로 소자를 위한 재료로서, Amorphous Oxide Semiconductor (AOS)가 주목받고 있다. AOS는 기존의 Amorphous Silicon과 비교하여 뛰어난 이동도를 가지고 있으며, 넓은 밴드 갭에 의한 투명한 광학적 특성을 가지고 있다. 이러한 장점을 이용하여, AOS 박막은 thin film transistor (TFT)의 active channel로 이용 되고 있다. 하지만, AOS를 이용한 TFT의 경우, 시간이 경과함에 따라 $O_2$ 및 $H_2O$ 흡착에 의해 전기적 특성이 변하는 현상이 있다. 이러한 현상은 소자의 신뢰성에 있어 중요한 문제가 된다. 이러한 문제를 연구하기 위해 본 논문에서는, AOS 박막을 이용하여 bottom 게이트형 TFT를 제작하였다. 이를 위해 먼저, p-type Si 위에 건식산화방식으로 $SiO_2$(100 nm)를 성장시켜 게이트 산화막으로 이용하였다. 그리고 Zn과 Sn이 1: 2의 조성비를 가진 ZnSnO (ZTO) 용액을 제조한 후, 게이트 산화막 위에 spin coating 하였다. Splin coating된 용액에 남아 있는 솔벤트를 제거하기 위해 10분 동안 $230^{\circ}C$로 열처리를 한 후, 포토리소그래피와 에칭 공정을 이용하여 ZTO active channel을 형성하였다. 그 후, 박막 내에 남아 있는 불순물을 제거하고 ZTO TFT의 전기적인 특성을 향상시키기 위하여, $600^{\circ}C$의 열처리를 30분 동안 진행 하여 junctionless형 TFT 제작을 완료 하였다. 제작된 소자의 시간 경과에 따른 열화를 확인하기 위하여, 대기 중에서 2시간마다 HP-4156B 장비를 이용하여 전기적인 특성을 확인 하였으며, 이러한 열화는 후처리 공정을 통하여 회복시킬 수 있었다. 열화의 회복을 위한 후처리 공정으로, 퍼니스를 이용한 고온에서의 열처리와 microwave를 이용하여 저온 처리를 이용하였다. 결과적으로, TFT는 소자가 제작된 이후, 시간에 경과함에 따라서 on/off ratio가 감소하여 열화되는 경향을 보여 주었다. 이러한 현상은, TFT 소자의 ZTO back-channel에 대기 중에 있는 $O_2$ 및 $H_2O$의 분자의 물리적인 흡착으로 인한 것으로 보인다. 그리고 추가적인 후처리 공정들에 통해서, 다시 on/off ratio가 회복 되는 현상을 확인 하였다. 이러한 추가적인 후처리 공정은, 열화된 소자에 퍼니스에 의한 고온에서의 장시간 열처리, microwave를 이용한 저온에서 장시간 열처리, 그리고 microwave를 이용한 저온에서의 단 시간 처리를 수행 하였으며, 모든 소자에서 성공적으로 열화 되었던 전기적 특성이 회복됨을 확인 할 수 있었다. 이러한 결과는, 저온임에도 불구하고, microwave를 이용함으로 인하여, 물리적으로 흡착된 $O_2$ 및 $H_2O$가 짧은 시간 안에 ZTO TFT의 back-channel로부터 탈착이 가능함과 동시에 소자의 특성을 회복 가능 함 의미한다.