• Title/Summary/Keyword: time-varying

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Chemical Oxidation Treatment of Hydrocarbon-Contaminated Eine Soil by ${H_2}{O_2}$/$Fe^0 System (${H_2}{O_2}$/$Fe^0시스템을 이용한 유류오염 미세토양의 화학적 산화처리)

  • 지원현;김지형;강정우;김성용;장윤영
    • Journal of Soil and Groundwater Environment
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    • v.6 no.3
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    • pp.13-20
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    • 2001
  • In this Study, application of ${H_2}{O_2}$/$Fe^0 oxidation System (Fenton-like oxidation) for the oxidative treatment of high-level soil contamination with hydrocarbon was suggested. The characteristics of Fenton-like oxidation of diesel-contaminated fine soil was experimentally probed in a batch system varying initial pH, zero valent iron and hydrogen peroxide levels, and initial diesel concentration. Contaminant degradation was identified by total petroleum hydrocarbon(TPH) concentration with gas chromatography. The batch experiments showed that the optimal ${H_2}{O_2}$and $Fe^0 dosage, 10% ${H_2}{O_2}$+ 20% $Fe^0 removed 65% of initial TPH concentration (10,000mg/kg) at a retention time of 24h. And the TPH removal in the ${H_2}{O_2}$/$Fe^0 system effectively proceeded only within a limited pH range of 3-4. The zero valent iron-catalyzed Fenton-like oxidation of diesel-contaminated soil was more competitive to the $FeSO_4-catalyzed system (Fenton oxidation) in removal efficiency and cost especially for the treatment of high level contamination.

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A Study on the Removal of Cu Impurity on Si Substrate and Mechanism Using Remote Hydrogen Plasma (리모트 수소 플라즈마를 이용한 Si 기판 위의 Cu 불순물 제거)

  • Lee, Jong-Mu;Jeon, Hyeong-Tak;Park, Myeong-Gu;An, Tae-Hang
    • Korean Journal of Materials Research
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    • v.6 no.8
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    • pp.817-824
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    • 1996
  • Removal of Cu impurities on Si substrates using remote H-plasma was investigated. Si substrates were intentionally contaminated by 1ppm ${CuCI}_{2}$, standard chemical solution. To determine the optimal process condition, remote H-plasma cleaning was conducted varying the parameters of rf power, cleaning time and remoteness(the distance between the center of plasma and the surface of Si substrate). After remote H-plasma cleaning was conducted, Si surfaces were analysed by TXRF(total x-ray reflection fluorescence) and AFM(atomic force microscope). The concentration of Cu impurity was reduced by more than a factor of 10 and its RMS roughness was improved by more than 30% after remote H-plasma cleaning. TXRF analysis results show that remote H-plasma cleaning is effective in eliminating Cu impurity on Si surface when it is performed under the optimal process condition. AFM analysis results also verifies that remote H-plasma cleaning makes no damage to the Si surface. The deposition mechanism of Cu impurity may be explained by the redox potential(oxidation-reduction reaction potential) theory. Based on the XPS analysis results we could draw a conclusion that Cu impurities on the Si substrate are removed together with the oxide by a "lift-off" mechanism when the chemical oxide( which forms when Cu ions are adsorbed on the Si surface) is etched off by reactive hydrogen atoms.gen atoms.

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A Study on Users' Perception towards the Utility of Publication Formats between Printed Books and Electronic Books of Korean Classics Collations and Translations (고전적(古典籍) 정리·번역서의 종이책과 전자책 이용에 대한 이용자 인식 연구)

  • Ko, Young Man;Shim, Wonsik;Song, Min-Sun;Yoon, Hyun Joung
    • Journal of the Korean Society for Library and Information Science
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    • v.52 no.1
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    • pp.259-283
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    • 2018
  • This research aims at understanding the differences between expert and general users' perceptions regarding publication preferences for Korean classics collations and translations in order to formulate future directions for these materials. For this purpose, an overview of changes in publishing in general as well as current status of collation/translation of Korean classics in particular are being identified. An online questionnaire was carried out in order to collect data regarding perceptions and preferences of expert users and general users of Korean classics. The results are based on the analyses of more than 1,000 responses. The analyses show that electronic books will not completely replace printed books and publishing both electronic and printed books in tandem for the time being is most preferable in order to satisfy varying user needs. Statistical analysis shows differences in terms of use value, value from possession, and readability of electronic and printed books in the two groups of users. However, as for the value of preservation by relevant institutions, there was a statistical difference between two groups towards printed books unlike their electronic equivalents. The research shows strong preference towards printed forms of classics collations and translations for the purpose of scholarly research and translation. Actual usage statistics reveal much heavy use of online database of classics translations compared to the use of available electronic books. For future publishing decisions for classics collations and translations will need to take into consideration of their special characteristics and symbolic nature. Proper representation of these materials into electronic format would require a standardized platform that enable various uses in different environments.

A Realtime Expression Control for Realistic 3D Facial Animation (현실감 있는 3차원 얼굴 애니메이션을 위한 실시간 표정 제어)

  • Kim Jung-Gi;Min Kyong-Pil;Chun Jun-Chul;Choi Yong-Gil
    • Journal of Internet Computing and Services
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    • v.7 no.2
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    • pp.23-35
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    • 2006
  • This work presents o novel method which extract facial region und features from motion picture automatically and controls the 3D facial expression in real time. To txtract facial region and facial feature points from each color frame of motion pictures a new nonparametric skin color model is proposed rather than using parametric skin color model. Conventionally used parametric skin color models, which presents facial distribution as gaussian-type, have lack of robustness for varying lighting conditions. Thus it needs additional work to extract exact facial region from face images. To resolve the limitation of current skin color model, we exploit the Hue-Tint chrominance components and represent the skin chrominance distribution as a linear function, which can reduce error for detecting facial region. Moreover, the minimal facial feature positions detected by the proposed skin model are adjusted by using edge information of the detected facial region along with the proportions of the face. To produce the realistic facial expression, we adopt Water's linear muscle model and apply the extended version of Water's muscles to variation of the facial features of the 3D face. The experiments show that the proposed approach efficiently detects facial feature points and naturally controls the facial expression of the 3D face model.

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Investigation on Beef Quality Indicator of Off-Flavor Development during Storage (쇠고기 저장 중 이취발생에 대한 Indicator 탐색)

  • Byeon, Ko-Eun;An, Soo-Rim;Shim, Soo-Dong;Lee, Jung-Young;Hong, Kwang-Won;Min, Sang-Gi;Lee, Seung-Ju
    • Food Science of Animal Resources
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    • v.29 no.3
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    • pp.325-333
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    • 2009
  • Beef quality indicators of off-flavor development during storage were investigated in terms of temperature dependence. The off-flavor development time (ODT) was detected using the R-index sensory test. During varying storage conditions at $25^{\circ}C$, $15^{\circ}C$, and $5^{\circ}C$, elements of beef quality were measured, such as volatile basic nitrogen (VBN), pH, color (CIE $L^*$, $a^*$, $b^*$), Warner-Bratzler shear force (WBSF), Pseudomonas spp. CFU, and lactic acid bacteria (LAB) CFU. A model with temperature dependence of ODT during storage was developed using Arrhenius-like equation, and a requirement with quality indicators was mathematically derived, resulting in similar temperature dependence. The temperature dependence of beef quality indicators was represented by the Arrhenius activation energy (Ea). Upon comparing the Ea of beef quality indicators and ODT, the temperature dependence similarity was found to be higher in the order of three groups: VBN, pH, $a^*$ value; LAB, Pseudomonas spp.; and WBSF, $L^*$ value, $b^*$ value. Therefore, VBN were determined as the most effective indicator of beef quality during off-flavor development.

Improvement of Grouting by Short-period Vibration Energy (단주기 진동에너지에 의한 그라우팅 보강효과)

  • Seo, Moonbok;Kwon, Sanghoon;Lee, Bongjik
    • Journal of the Korean GEO-environmental Society
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    • v.16 no.7
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    • pp.35-42
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    • 2015
  • Grouting method has been widely used for the ground improvement and stabilization: mostly to block or control the ground water in the early years and to improve the ground, repair the structure in recent years, ever increasing its use. Despite many advantages so far, the existing grouting method also has some shortcomings including uncertain permeation of grouting with gravity type if the voids between the soil particles are narrow, and problems due to the relaxation of the neighboring ground when injected using injection pressure. As an alternative, a vibration injection method with constant amplitude and frequency has been developed in recent years, with the vibration grouting being reported to have a permeability increasing effect of grout material compared with the positive pressure injection type. Accordingly, the purpose of this study is to investigate the improvement effect of the vibration grouting that applies short-period vibration energy by varying vibration cycle, vibration time and ground conditions to evaluate the strength enhancing effect of grouting materials, expansion effect of grouting body, ground improvement effect of the grouting and the penetration characteristics of the rock joint. The findings of this study show the improved compressive strength of grout, expansion of grouting body and increased penetration rate, according to the vibration compared with non-vibration under the loose soil condition.

Feasibility of Using Norad Orbital Elements for Pass Programming and Catalog Generation for High Resolution Satellite Images (고해상도 위성영상 촬영계획 수립 및 카탈로그 생성을 위한 NORAD 궤도 데이터의 이용 가능성 연구)

  • 신동석;김탁곤;곽성희;이영란
    • Korean Journal of Remote Sensing
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    • v.15 no.2
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    • pp.119-130
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    • 1999
  • At present, many ground stations all over the world are using NORAD orbit element data in order to track and communicate with Earth orbiting satellites. The North American Aerospace Defense Command (NORAD) observes thousands of Earth orbiting objects on daily basis and provides their orbital information via internet. The orbital data provided by NORAD, which is also called two line element (TLE) sets, allows ground stations to predict the time-varying positions of satellites accurately enough to communicate with the satellites. In order to complete the mission of a high resolution remote sensing satellite which requires very high positional determination and control accuracy, however, a mission control and tracking ground station is dedicated for the observation and positional determination of the satellite rather than using NORAD orbital sets. In the case of KITSAT-3, NORAD orbital elements are currently used for image acquisition planning and for the processing of acquired images due to the absence of a dedicated KITSAT-3 tracking ground system. In this paper, we tested and analyzed the accuracy of NORAD orbital elements and the appropriate prediction model to determine how accurately a satellite acquisites an image of the location of interest and how accurately a ground processing system can generate the catalog of the images.

Polymerization Behavior of Self-healing Agents for Damage Repair in Composite Materials (복합재 손상보수용 자가치료제의 중합 거동)

  • Oh, Jinoh;Yoon, Sungho;Jang, Seyong
    • Journal of the Korean Society of Propulsion Engineers
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    • v.18 no.5
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    • pp.35-42
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    • 2014
  • Thermal analysis properties and adhesive properties of self-healing agents were evaluated through differential scanning calorimetry, reaction heat measurement, and adhesive shear test. D1E0, D3E1, D1E1, D1E3, and D0E1, depending on the mixing ratio of DCPD and ENB, were considered as self-healing agents. The amount of Grubbs' catalyst, depending on the type of self-healing agents, was varied from 0.1 wt% to 1.5 wt%. In the case of DCPD, the polymerization reaction occurred faster and the stabilized adhesive strength increased as the amount of catalyst increased; however, a large amount of catalyst was required. ENB had excellent reactivity with a small amount of the catalyst; however, high reaction heat was observed at the early stage of polymerization. Thermal analysis properties and adhesive properties of self-healing agents can be controlled by varying a mixing ratio of DCPD and ENB. Among the self-healing agents used for this study, the D3E1 would be one of the most preferable candidates with regard to maximum adhesive strength, reaching time to maximum adhesive strength, stabilized adhesive strength, and reaction heat.

A Study of Heat Transfer during Freezing Process of Water in a Vertical Cylinder - Comparison of thermal storage performance on the working fluid direction - (수직원통형 축열조내 물의 응고과정시 열전달에 관한 실험적연구 - 작동유체의 유동방향에 따른 열저장성능 비교 -)

  • Heo, K.;Kim, Y.K.;Kim, Y.J.;Kim, J.K.;Yim, C.S.
    • Solar Energy
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    • v.15 no.2
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    • pp.77-90
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    • 1995
  • An effective heat transfer during freezing process was proposed in the vertical cylinder to improve the effectiveness of the heat storage. Vertical cylinder was filled with pure water in order to investigate ice-shape, temperature distribution of the liquid, temperature distribution of the cylinder tube wall, total heat storage per unit mass in the test section under the two experimental conditions; inlet temperature of working fluid is constant($-10^{\circ}C$) and inlet direction of working fluid is either upward flow or downward. Both the mean temperature of the liquid and temperature difference of cylinder tube wall in the upward were lower than those in the downward. In case that the initial temperature of water was $7^{\circ}C$ and $4^{\circ}C$, the shape of ice layer in the upward was more uniform than that in the downward. In case of $1^{\circ}C$, the shape of ice layer is formed by inlet direction of working fluid. Finally, time-varying total heat energy stored in the water in the upward was higher than that in the downward.

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Adhesion Properties of UV-curable Acrylic PSA Tape for Automotive Sidemolding and Emblem (자동차용 사이드 몰딩과 엠블럼 적용을 위한 UV 경화형 아크릴 점착 테이프의 점착물성)

  • Park, Ji-Won;Lee, Seung-Woo;Kim, Hyun-Joong;Won, Dong-Bok;Kim, Dong-Bok;Lee, Kang-Shin;Woo, Hang-Soo;Kim, Eun-Ah
    • Journal of Adhesion and Interface
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    • v.12 no.3
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    • pp.81-87
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    • 2011
  • In this study, UV curing and crosslinking process was introduced for synthesis of acrylic foam tape that can be applied to the the automotive assembly process. Polymerized adhesive are laminated to baseform and varying the thickness of specimens were prepared. To measure basic mechanical properties, stainless steel was used. And in the test peel, dynamic shear and t-block were used. The acrylform adhesive show better results compare with typical adhesive and the properties depand on external factors - thick, wetting time -. To analysis functions of acrylic foam adhesive used to automobile production, evaluate the adhesive properties on the various plastic substrate. In PP and PE are categorized low surface energy materials, their properties have not been expressed. But dynamic shear tests show that some properties could be expressed by the difference break mechanism.