• Nuclear Engineering and Technology
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• 제43권1호
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• pp.7-12
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• 2011

In this paper we review the neutron scattering work performed on 3 different antiferromagnetic pyrochlores which reveal how the character of the magnetic interactions plays a major role on the eventual outcome of the magnetic ground state. $Tb_2Ti_2O_7$, $Er_2Ti_2O_7$ and $Y_2Mo_2O_7$ have all been extensively studied over the past 15 years and are known to display, respectively, spin liquid, long range ordered and glassy ground states. Although detailed experiments have been performed on these compounds, and much is known about their low temperature properties, a detailed theoretical understanding of their ground states remains elusive.

• 대한원격탐사학회지
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• 제23권3호
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• pp.189-198
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• 2007

Introduction of lidar technology have contributed to a wide range of applications in generating quality surface models. Accordingly, because of the importance of terrain surface models in mapping applications, rigorous studies have been performed to extract ground points from a lidar data point cloud. Although most filters have been shown abilities to extract ground points with their parameters tuned, however, most experiments revealed that there are certain limitations in optimizing filter parameters and the correction of remaining misclassified points is not straightforward. In this study, therefore, a method to improve the quality of filtered lidar data is proposed, which exploits neighboring surface properties arising between immediate neighbors. The method comprises a sequence of procedures which can reduce commission and omission errors. Commission errors occurring in low-rise objects are reduced by utilizing morphological operations. On the other hand, omission errors are reduced by adding missing ground points around step edges. Experimental results show that the qualities of filtered data can be improved considerably by the proposed method.

• Bulletin of the Korean Chemical Society
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• 제13권2호
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• pp.140-145
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• 1992

The excited state intramolecular proton transfer and physical properties of 7-hydroxyquinoline are studied in various solutions and heterogeneous systems by measuring steady state and time-resolved fluorescence, reflection and NMR spectra. Proton transfer is observed only in protic solvents owing to its requirement of hydrogen-bonded solvent bridge for proton relay transfer. The activation energies of the proton transfer are 2.3 and 5.4 kJ/mol in $CH_3OH$ and in $CH_3OD$, respectively. Dimers of normal molecules are stable in microcrystalline powder form and undergo an extremely fast concerted double proton transfer upon absorption of a photon, consequently forming dimers of tautomer molecules. In the supercage of zeolite NaY, its tautomeric form is stable in the ground state and does not show any proton transfer.

• Food Science and Biotechnology
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• 제14권6호
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• pp.758-765
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• 2005

Instant powders that only require mixing with water prior to consumption can be produced by extrusion for use in products such as instant beverages. Both extrusion processing conditions and particle size of powder are important to end-product characteristics. In this study, a twin-screw extruder was used under various processing conditions (feed moisture, barrel temperature, and screw speed) to produce extrudates from soft wheat flour, which were ground to powders with particle size ranges of less than 93, 93-145, and $145-249\;{\mu}m$. Effects of adding soy lecithin to wheat flour before extrusion were also investigated. Water absorption, solubility, suspension viscosity, and dispersibility of wheat powders were related to specific. mechanical energy measured during extrusion. Powder particle size was important to instant properties, especially ease of dispersal in water and stability to sedimentation. Addition of lecithin significantly improved dispersibility of powders.

• 한국언어정보학회지:언어와정보
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• 제1권
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• pp.227-276
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• 1997

There has been no nuanimous analysis of specific indefinites. It is still disputed even whether specificity is a matter of semantics of pragmatics. In this paper, I introduce some properties of specific indefinites, and explain them based on the meaning of specificity. Specificity intuitively means that the speaker or someone else in the context has some individual in mind, which is generally accepted among liguistics. The main issue is how to represent the meaning of 'have-in-mind'. I review some philosophical discusstions of cognitive contact and show that when the use of an expression involves 'have-in-mind', the expression is rigid designator in the belief of the agent who has an individual in mind. in the use of a specific indefinite, this applies only to the information state of the agent of 'have-in-mind'. To represent this asymmetry, I propose a new theory of dynamic semantics, in which a common ground consists of multiple information states, as many as the number of the participants in a conversation. Moreover, each information state is structured as a set of epistemic alternatives, which is a set of possible information states of a participant in the context. Based on this semantics, the properties of specific indefinites are explained.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.126-133
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• 2008

Geotechnical limit state design methods; LRFD of North America is an approach that estimates resistance using design model and then multiplies resistance factor by calculated resistance to reflect the uncertainty of geomaterials and design models; whereas, Eurocode of the Europe employs the partial resistance factor applied directly to each variable in the resistance equation that individual soil properties such as cohesion and angle of internal friction are applied. This discussion paper is a study on characteristic value which has globally been argued through processing of development of Eurocode 7 for geotechnical design even to the present. Estimating the characteristic value of soil properties affects not only determination of design value applied directly to design of geotechnical structures, but also economic feasibility and stability of the structures.

• 천문학회보
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• 제46권2호
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• pp.59.2-59.2
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• 2021

On March 6 2021, Apophis made a close approach to the Earth with a minimum distance of 0.11 AU when the apparent magnitude reached up to V~16. This was the most favorable condition to observe this asteroid until its 2029 encounter. The observations during this apparition were extremely important to determine major physical properties, such as size, rotational state, 3D shape model, surface mineral properties. So, we organized the observation campaign during the 2021 apparition. The main goals of our campaign are to refine the spin state and 3D shape model and check the surface composition variations. The campaign involved dozens of countries and included ground-based photometry and spectroscopy, and spacecraft observations. Our timely observation campaign will provide essential data in planning the operation scenario for the space mission. In this presentation, we will report the preliminary result of the Apophis observation campaign during the 2021 apparition.

• 한국축산식품학회지
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• 제29권6호
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• pp.680-684
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• 2009

The effects of garlic and onion on the microbiological and physicochemical properties of irradiated ground beef patties were evaluated. Ground beef was mixed with 0.5%(w/w) minced garlic or 2.5%(w/w) minced onion, vacuum-packed in oxygen-impermeable nylon/PE bags and then electron beam-irradiated at 2.5 kGy. All samples were kept at $4^{\circ}C$ for 8 d. Irradiation resulted in a 2-log CFU/g reduction in both aerobic and coliform bacteria. The microbial counts gradually increased during storage, but those in beef that contained garlic or onion were 1-log CFU/g lower than those of the control samples after 8 d of storage. The pH value decreased during storage in all meat samples, but this decrease was greater in non-irradiated beef than in irradiated beef. The lipid oxidation, volatile basic nitrogen content and Hunter color values of raw patties were generally not affected by irradiation or the addition of garlic and onion. Sensory evaluation of cooked patties showed that the off-odor was less pronounced in samples that contained added garlic or onion than in control samples, and that the overall acceptability of beef formulated with garlic was the highest. Overall, the results of this study indicate that the addition of garlic or onion in combination with irradiation treatment enhanced the microbial quality and improved the sensory quality of irradiated ground beef.

• 한국재난정보학회 논문집
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• 제15권1호
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• pp.1-11
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• 2019

연구목적 : 본 연구는 경상남북도의 국가지정 중요목조문화재 주변 환경에 따라 방재특성이 어떻게 다른지를 파악하고 이를 바탕으로 문화재 주변 환경에 맞는 목조문화재 방재대책을 검토하고자 한다. 연구방법 : 연구를 위해 경상남도와 경상북도에 있는 문화재 지정 현황 및 특성을 파악하고 재난이력을 통하여 경상남도 및 경상북도에 있는 문화재의 피해 현황을 검토하였다. 또한 경상남도와 경상북도에 있는 국가지정 중요목조문화재 58개소를 대상으로 주변 환경에 따라 산악, 농촌, 도시지역으로 나누어 방재특성을 분석하였다. 연구결과 : 도시지역에 위치한 문화재는 안전경비인력의 배치가 적절했고 방재훈련이 잘 이루어지고 있었으며 진입여건은 신속하게 진입할 수 있었다. 농촌지역은 방염사업이 잘 실시되어 있었고 평탄한 곳에 위치한 문화재가 많았다. 산악지역은 진입여건이 타 지역에 좋지 않았으며 과거 재난 발생이력도 가장 많았다. 결론 :첫째, 도시지역의 목조문화재 경우 초기 대응을 위한 자위소방대 배치인력 확보 및 방재교육을 강화해야 한다. 둘째, 농촌지역의 목조문화재 경우 문화재 보호를 위한 방충사업, 방재보험 등의 예방사업을 실시해야 한다. 셋째, 산악지역의 목조문화재 경우 자체적인 대응역량을 강화하기 위한 방안을 마련해야 한다.

• Macromolecular Research
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• 제13권1호
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• pp.30-38
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• 2005

Sulfur-cured gum natural rubber vulcanizates were devulcanized using two different concentrations of diallyl disulfide. The devulcanization process was performed at $110^{\circ}C$ min in an open two-roll cracker-cum-mixing mill. Natural rubber vulcanizates having various sulfur/accelerator ratios were used to study the cleavage of monosulfide, disulfide, and polysulfide bonds. The properties of devulcanized natural rubber increased upon increasing the disulfide concentration and the mechanical properties of the revulcanized natural rubber increased upon decreasing the sulfur content in the original rubber vulcanizates. The scorch time and the maximum state of cure both increased when the ground vulcanizates were treated with higher amounts of disulfide. TGA and DMA were conducted to study the effects of the devulcanization on the thermal stability and the $T_g$ behavior of the vulcanizates. SEM analysis was conducted to study how the failure mechanism was affected by the devulcanization process. It was possible to recover $70-80\%$ of the original gum rubber properties by using this process. From IR spectroscopic analysis, we observed that the oxidation of the main chains did not occur during high-temperature milling.