• The Korea Journal of Herbology
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• 제28권3호
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• pp.39-44
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• 2013

Objectives : The purpose of this study was to identify active fraction and components from antiplatelet Ulmi cortex extract. Methods : The 70% ethanol extract of Ulmi cortex was subjected to column chromatography over D101 resin and eluted with an 20% (W1), 30% (W2), 40% (W3), 50%(W4), 70% (W5), and 100% ethanol (W6) to yield 6 fractions. W6 was further fractioned and its active components were purified using semi-preparative HPLC. The isolated compounds were identified by MS and NMR, and their contents were simultaneously analyzed using HPLC/UV. Antiplatelet aggregation activities of the fractions and the compounds were evaluated using rat platelet-rich plasma in presence of collagen ($5{\mu}g/ml$), arachidonic acid (0.05 U/ml), or thrombin ($100{\mu}M$). Results : Among six fractions, W3 prominently inhibited platelet aggregation. At the concentration of $200{\mu}g/ml$, W3 strongly inhibited arachidonic acid- and collagen-induced platelet aggregations by 78.2% and 65.9%, respectivley, and weakly inhibited thrombin-inducded platelet aggregation by 32.6%. Catechin, epicatehin, and catechin-7-O-${\beta}$-D-glucopyranoside were isolated from W3 and their contents were revealed to be 15.1%, 0.87%, and 0.32%. Catechin and epicatechin at the concentrations of $100{\mu}M$ strongly inhibited collagen-induced platelet aggregation by 79.9% and 86.6%, respectively, but weakly inhibited arachidonic acid- and thrombin-induced platelet aggregations. Conclusions : A main active principle of anitplatelet Ulmi Cortex extract is W3 fraction, of which main active component is catechin considering its antiplatelet activity and content.

• Journal of the Korean Society of Industry Convergence
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• 제25권4_2호
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• pp.549-563
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• 2022

Continuous global warming is causing ecosystem destruction and direct damage to human life. The main cause of global warming is greenhouse gases, which account for more than 90 % of carbon dioxide. The leaders of each country signed the Paris Agreement at the United Nations Convention on Climate Change (UNFCCC) to reduce greenhouse gas emissions. Currently, the total amount of CO₂ emitted from South Korea is 664.7 million tons as of 2018, ranking eighth in the world. 37 % of South Korea's total CO₂ emissions come from the construction & building field, especially the cement production, which is a construction material. Carbon reduction technologies can be largely divided into four types: carbon reduction (CC), carbon reduction and storage technology (CCS), carbon reduction and utilization technology (CCU), and carbon reduction, storage and utilization technology (CCUS). Overseas, CCUS technology is mainly applied to reduce and store CO₂ emitted from construction and construction field. A technology for permanently storing CO₂ through mineralization by capturing CO₂ and utilizing CO₂ into a cement production process was developed, and this technology is applied to the entire cement industry. However, the development of CCUS technology applicable to the cement industry is still insignificant in South Korea. In this study, carbon dioxide reduction technology and methods for reducing carbon dioxide emitted during the cement manufacturing process, which is the main component of concrete mainly used in civil engineering construction, were investigated. Overseas, it has reached the commercialization stage beyond the demonstration stage as a way to reduce carbon dioxide by vomiting carbonation reactions. Accordingly, if carbon dioxide reduction plan technology generated during cement manufacturing is developed based on domestic technology differentiated from foreign technology, it is expected to contribute one more step to the carbon neutrality policy.

• International conference on construction engineering and project management
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.725-731
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• 2009

Construction documents are recognized as an essential component for making a decision and supporting on construction processes. In construction, the management of project document is a complex process due to different factors such as document types, stakeholder involvement, document flow, and document flow processes. Therefore, inappropriate management of project documents can cause several impacts on construction work processes such as delay or poor quality of work. Several information and communication technologies (ICT) were proposed to overcome problems concerning document management practice in construction projects. However, the adoption of ICT may have some limitation on the compatibility of specific document workflow. Lack of understanding on designing document system may cause many problems during the use and implementation phase. Thus, this paper proposes the framework that integrates Soft System Methodology (SSM) concept and Integrated Definition Modeling Technique (IDEF) for analyzing document management system in construction project. Research methodology is classified as the case study. Five main construction building projects are selected as case studies. The qualitative data related to problems and processes are collected by interviewing construction project participants such as main contractors, owners, consultants, and designers. The findings from case study show the benefits of using SSM and IDEF. The use of SSM can help identify the problems in managing construction document in rich picture view whereas IDEF can illustrate the document flow in construction project in details. In addition, the idea of integrating these two concepts can be used to identify the root causes of process problems at the information level. As the results, this idea can be applied to analyze and design web-based document management system in the future.

• The Bulletin of The Korean Astronomical Society
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• 제46권2호
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• pp.40.2-40.2
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• 2021

The impact of AGN on star formation is one of the main questions in AGN-galaxy coevolution studies. However, direct evidence of AGN feedback is still rare. One of the main obstacles is that various star formation rate (SFR) indicators are contaminated by AGN contribution. We present IR-based SFR measurements of a sample of 52 local (z<0.3) AGNs, which were selected based on kinematical properties of ionized gas outflows, using SED analysis with JCMT/SCUBA-2 data. First, we will compare IR-based SFR with other SFR indicators to check the reliability of the SFR indicators. Second, we will discuss the contribution of Mid-IR emission from hot dust of AGN torus by comparing SED fitting results with and without including AGN dust component. Finally, we will report the correlation between specific SFR (sSFR) and AGN activity (e.g., outflow strength or Eddington ratio) as evidence of no instantaneous feedback and discuss the implications of these results

• Journal of English Language & Literature
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• 제56권6호
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• pp.1047-1065
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• 2010

English inversion constructions are not only hard for non-native speakers to learn but also difficult to teach mainly because of their intriguing grammatical and discourse properties. This paper addresses grammatical issues in learning or teaching the so-called 'predicate inversion (PI)' construction (e.g., Equally important in terms of forest depletion is the continuous logging of the forests). In particular, we chart the grammatical (distributional, syntactic, semantic, pragmatic) properties of the PI construction, and argue for adata-driven teaching for English grammar. To depart from the arm-chaired style of grammar teaching (relying on author-made simple sentences), our teaching method introduces a datadriven teaching. With total 25 university students in a grammar-related class, students together have analyzed the British Component of the International Corpus of English (ICE-GB), containing about one million words distributed across a variety of textual categories. We have identified total 290 PI sentences (206 from spoken and 87 from written texts). The preposed syntactic categories of the PI involve five main types: AdvP, PP, VP(ed/ing), NP, AP, and so, all of which function as the complement of the copula. In terms of discourse, we have observed, supporting Birner and Ward's (1998) observation that these preposed phrases represent more familiar information than the postposed subject. The corpus examples gave us the three possible types: The preposed element is discourse-old whereas the postposed one is discourse-new as in Putting wire mesh over a few bricks is a good idea. Both preposed and postposed elements can also be discourse new as in But a fly in the ointment is inflation. These two elements can also be discourse old as in Racing with him on the near-side is Rinus. The dominant occurrence of the PI in the spoken texts also supports the view that the balance (or scene-setting) in information structure is the main trigger for the use of the PI construction. After being exposed to the real data and in-depth syntactic as well as informationstructure analysis of the PI construction, it is proved that the class students have had a farmore clear understanding of the construction in question and have realized that grammar does not mean to live on by itself but tightly interacts with other important grammatical components such as information structure. The study directs us toward both a datadriven and interactive grammar teaching.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제5B권3호
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• pp.289-295
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• 2005

Instrumentation and Control (I&C) of the Neutral Beam Test Stand (NB- TS) Facility at the Korea Atomic Energy Research Institute (KAERI) for the Korea Superconducting Tokamak Advanced Research (KSTAR) project has been underway since the start of the project to answer the diverse requests arising from the various facets of the development and construction phases of the project. Optical signal transmission constitutes a significant portion of I&C works and has been performed for the entirety of the project. During the NB- TS construction and related experiments, significant achievements to a more accurate as well as more refined optical signal transmissions have been made. Examples of those I&C works that utilized the optical signal transmission are the Langmuir probe signal transmission, gradient grid current signal transmission, gas flow control and signal transmission, ion source temperature measurement, beam line component temperature monitoring, and coolant flow signal transmission, etc. These optical signal transition provisions are now performing part of the indispensable functions for the proper operation of the NB- TS facility. Attained experience and expertise are expected to be well applied to the upcoming main neutral beam injection (NBI) system construction for the KSTAR project.

• Journal of Korean Society of Water and Wastewater
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• 제23권6호
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• pp.855-864
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• 2009

The main object of this work was to determine the influence of periodic chemical backwash on filtration resistance in membrane filtration system. In this work Hermia's models were used to investigate the fouling mechanisms involved in the microfiltration of $0.45{\mu}m$ filtered sewage feed. Batch microfiltration experiments were performed at transmembrane pressure 0.4 bar and different feed SCOD concentration (9~67 mgSCOD/L). The results showed that the best fit to experimental data corresponded to the intermediate blocking model followed by the standard and complete blocking model for all the experimental conditions tested. From the simulation results of filtration performance, it was found that in order to maintain sustainable operation of membrane filtration system, irreversible foulant component accumulated continuously on membrane surface and/or pore must be effectively removed. In addition, it was verified that periodic chemical backwash using NaOCl or NaOH effectively improved filtration performance of membrane.

• Journal of Welding and Joining
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• 제26권1호
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• pp.69-75
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• 2008

Spot welding which use the main process for side block production of stainless steel railway vehicle is legged behind in laser welding about a quality and productivity. Although the laser welding has many potential advantages such as low heat input and aspect ratio of weld bead, its application to a new structural component still is required many engineering data including mechanical properties such as tensile, fatigue strength, etc on. Therefore, experimental analysis was carried out to understand the fatigue phenomena of different thickness stainless steel overlap joining panels by Nd:YAG laser welding. The fatigue life curves were obtained through fatigue tests with the various levels of applied load. The fatigue life is related with the parameters such as gap size and penetration depth through experiment. As the results, tensile strength and fatigue life were proportional in heat input level and gap was identified the major factor for fatigue life. Also we could know that deferent a-ferrite content at HAZ depend on welding heat input was important factor to determine a formation of initial crack and total fatigue life cycle.

• Journal of the Korean Ceramic Society
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• 제46권3호
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• pp.253-262
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• 2009

The purpose of this study is to find out optimum conditions for zinc crystalline glaze under variables of firing: maximum firing temperature, crystal growth temperature, temperature increasing speed, annealing speed, holding time at maximum temperature and holding time at crystal growth temperature. Ferro Frit3110, ZnO and Quartz were used as starting materials and tested by three component system. The best result of test was selected and extended to its vicinity as five glaze formulas. And then the specimens were experimented by variable firing conditions and analyzed by crystal appearance observation, XRD, FT-IR and Raman spectroscopy. In result, main crystal was willemite in the zinc glazes. Some gahnite was detected in specimens which were fired at $1230^{\circ}C$, $1250^{\circ}C$ and $1270^{\circ}C$, however gahnite was not identified at $1300^{\circ}C$. Optimum zinc crystalline glaze was gained by following firing condition: temperature increasing speed $5^{\circ}C$/min, holding 1 h at $1270^{\circ}C$, annealing speed $3^{\circ}C$/min till $1170^{\circ}C$, holding 2 h at $1170^{\circ}C$ then naturally annealed.

• International Journal of Contents
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• 제6권2호
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• pp.1-5
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• 2010

The rapid growth in communication technology has led to the development of effective ways of sharing ideas and information in the form of speech and images. Understanding this information has become an important research issue and drawn the attention of many researchers. Text in a digital image contains much important information regarding the scene. Detecting and extracting this text is a difficult task and has many challenging issues. The main challenges in extracting text from natural scene images are the variation in the font size, alignment of text, font colors, illumination changes, and reflections in the images. In this paper, we propose a connected component based method to automatically detect the text region in natural images. Since text regions in mages contain mostly repetitions of vertical strokes, we try to find a pattern of closely packed vertical edges. Once the group of edges is found, the neighboring vertical edges are connected to each other. Connected regions whose geometric features lie outside of the valid specifications are considered as outliers and eliminated. The proposed method is more effective than the existing methods for slanted or curved characters. The experimental results are given for the validation of our approach.