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Development of Photothermal Mirage Technique for Measuring Thermal Diffusivity (열확산도 측정을 위한 광열 신기루 기법 개발)

  • Choi, Sun-Rock;Lee, Joo-Chul;Kim, Dong-Sik
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.9
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    • pp.1220-1228
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    • 2003
  • The mirage technique is proved to be powerful in measuring the thermal diffusivity of materials. In particular, its contactless nature makes it suitable for delicate samples and microscale structures. In this study, thermal-wave-coupling method is developed in a general form for both thermally thin and thick samples. In the suggested measuring scheme, the probe beam can be positioned close to the pump beam and the absolute position need not be measured. Therefore the new scheme provides a relatively simple yet effective way to determine the thermal diffusivity of thermally thick samples. Thermal diffusivities of bulk samples like Ni and Al were measured and the characteristics of mirage signal for a thin film were observed by using the mirage experimental setup. The apparent thermal diffusivity was measured by varying such parameters as probe beam height, size of pump beam, power of pump beam, and surface condition of sample. From the practical standpoint, it is shown that the size of the pump beam is the most important factor for accurate thermaldiffusivity measurement. Experiments using thin-film samples show that the thermal diffusivity of a substrate covered with thin film can be measured by photothermal mirage signals.

Antiinflammatory and antioxidative effects of Agrimonia pilosa Ledeb

  • Sim, SY;Kim, GJ;Ko, SG
    • Advances in Traditional Medicine
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    • v.7 no.3
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    • pp.217-228
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    • 2007
  • Agrimonia pilosa Ledeb. has long been used for a useful natural agent ameliorating inflammation related symptoms in the folk medicine recipe. This study was performed to investigate effects of Agrimonia pilosa Ledeb.(AP) on the expression of inflammation related genes such as the inducible nitric oxide synthase (iNOS) in macrophage cell line, RAW 264.7 cells. The AP (whole plants) was extracted with 80% ethanol and sequentially partitioned with solvents in order to increase polarity. Among the various solvent extracts of AP, the n-butanol (BuOH) fraction showed the most powerful inhibitory ability against nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW 264.7 cells without affecting cell viability. Reverse transcriptase-polymerase chain reaction and Western blot analysis revealed that the BuOH fraction provided a primary inhibitor of the iNOS protein and mRNA expression in LPS-induced RAW 264.7 cells. The DPPH and OH radical scavenging activities of the several fractions of 80% ethanol extracts of AP significantly increased by EtOAC and BuOH fractions. Thus, the present study suggests that the response of a component of the BuOH fraction to NO generation via iNOS expression provide an important clue to elucidate anti-inflammatory mechanism of AP.

Time Series Forecasting Based on Modified Ensemble Algorithm (시계열 예측의 변형된 ENSEMBLE ALGORITHM)

  • Kim Yon Hyong;Kim Jae Hoon
    • The Korean Journal of Applied Statistics
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    • v.18 no.1
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    • pp.137-146
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    • 2005
  • Neural network is one of the most notable technique. It usually provides more powerful forecasting models than the traditional time series techniques. Employing the Ensemble technique in forecasting model, one should provide a initial distribution. Usually the uniform distribution is assumed so that the initialization is noninformative. However, it would be expected a sequential informative initialization based on data rather than the uniform initialization gives further reduction in forecasting error. In this note, a modified Ensemble algorithm using sequential initial probability is developed. The sequential distribution is designed to have much weight on the recent data.

FE MODEL UPDATING OF ROTOR SHAFT USING OPTIMIZATION TECHNIQUES (최적화 기법을 이용한 로터 축 유한요소모델 개선)

  • Kim, Yong-Han;Feng, Fu-Zhou;Yang, Bo-Suk
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.11a
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    • pp.104-108
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    • 2003
  • Finite element (FE) model updating is a procedure to minimize the differences between analytical and experimental results, which can be usually posed as an optimization problem. This paper aims to introduce a hybrid optimization algorithm (GA-SA), which consists of a Genetic algorithm (GA) stage and an Adaptive Simulated Annealing (ASA) stage, to FE model updating for a shrunk shaft. A good agreement of the first four natural frequencies has been achieved obtained from GASA based updated model (FEgasa) and experiment. In order to prove the validity of GA-SA, comparisons of natural frequencies obtained from the initial FE model (FEinit), GA based updated model (FEga) and ASA based updated model (FEasa) are carried out. Simultaneously, the FRF comparisons obtained from different FE models and experiment are also shown. It is concluded that the GA, ASA, GA-SA are powerful optimization techniques which can be successfully applied to FE model updating, the natural frequencies and FRF obtained from all the updated models show much better agreement with experiment than that obtained from FEinit model. However, FEgasa is proved to be the most reasonable FE model, and also FEasa model is better than FEga model.

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Effects of prenatal cocaine exposure on the developing rat :Pharmacological and neurobehavioral studies

  • Park, Sun-Ju
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1996.11a
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    • pp.171-172
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    • 1996
  • Cocaine is a powerful reinforcer that has become a popular drug of abuse in man. CNS effects that are related to the abuse of cocaine include feeling of well-being and euphoria. Brain dopamine systems are thought to mediate reinforcement and it is often assumed that cocaine's inhibition of dopamine uptake is the mechanism underlying its reinforcing effects. With increase in cocaine use among general population in recent years, adverse effects of the drug have occurred in all social strata and age groups. Therefore, it has been recognized that the epidemic of cocaine abuse is a growing major concerning public health. One of the most troubling aspects of cocaine abuse is its use by pregnant women. Drug abuse during pregnancy puts two lives at risk. Cocaine produces toxic effects on the fetus at concerntrations that are apparently nontoxic to the mother. Not only does cocaine cross the placenta via diffusion and via rapid penetration to mucous membranes, due to its high lipid solubility, but cocaine can also be found in breast milk, the effects of the cocaine can persist long after the child is born. Although it is known that prenatal cocaine exposure is associated with developmental risk to the fetus ana newborn, few studies have been conducted to assess the mechanisms whereby either short-term or long-term administration of cocaine can exert its harmful effects on the mother or the child. Therefore, it was our great interest to investigate the pharmacological and neurobehavioral changes in offspring that are prenatally exposed to cocaine.

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Application of Metabolomics to Quality Control of Natural Product Derived Medicines

  • Lee, Kyung-Min;Jeon, Jun-Yeong;Lee, Byeong-Ju;Lee, Hwanhui;Choi, Hyung-Kyoon
    • Biomolecules & Therapeutics
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    • v.25 no.6
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    • pp.559-568
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    • 2017
  • Metabolomics has been used as a powerful tool for the analysis and quality assessment of the natural product (NP)-derived medicines. It is increasingly being used in the quality control and standardization of NP-derived medicines because they are composed of hundreds of natural compounds. The most common techniques that are used in metabolomics consist of NMR, GC-MS, and LC-MS in combination with multivariate statistical analyses including principal components analysis (PCA) and partial least squares-discriminant analysis (PLS-DA). Currently, the quality control of the NP-derived medicines is usually conducted using HPLC and is specified by one or two indicators. To create a superior quality control framework and avoid adulterated drugs, it is necessary to be able to determine and establish standards based on multiple ingredients using metabolic profiling and fingerprinting. Therefore, the application of various analytical tools in the quality control of NP-derived medicines forms the major part of this review. $Veregen^{(R)}$ (Medigene AG, Planegg/Martinsried, Germany), which is the first botanical prescription drug approved by US Food and Drug Administration, is reviewed as an example that will hopefully provide future directions and perspectives on metabolomics technologies available for the quality control of NP-derived medicines.

Open mathematics education and Modelling (열린수학과 모델링)

  • 조완영;권성룡
    • Journal of Educational Research in Mathematics
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    • v.8 no.2
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    • pp.663-677
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    • 1998
  • The development of Science and Technology and the social change require new paradigm in Education. In a traditional paradigm, learners have been regarded as a passive being and knowledge could be transmitted to learner. But within this paradigm, it is difficult to confront the social change and to develop problem solving skills in various context. This results in a new, alternative perspective, Constructive paradigm. As an alternative to the traditional settings, Constructive paradigm emphasizes the learner centered instruction. The reform movement in mathematics education including NCTM's standards revolves around this paradigm and the open education movement in our educational system is based on it. Open education values learner's interest, autonomy and internal motivation in learning. However, open education has been misunderstood by most of the teachers. It should be understood as the change of paradigm. In this study, as a way of helping students connect mathematics to their everyday lives and construct meaningful mathematical knowledge and concept, mathematical modelling is suggested. It consists of posing and specifying the real problem, formulation and constructing a mathematical model, analyzing and solving a mathematical problem. interpreting the solution and comparing with reality and communicating results. In this process, technology like computer can be a powerful tool. It can help students explore various problems more easily and concretely.

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A study on the plasticity of Gaya relice for the development of local cultural goods (지역문화상품 개발을 위한 가야유물의 조형성 연구)

  • Song, Mi-Jung;Park, Hye-Won
    • Journal of Fashion Business
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    • v.14 no.5
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    • pp.158-175
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    • 2010
  • Culture means a lifestyle realizing a definite object or ideal. Each local special culture is enormous in value as a local culture inheritance. If it is developed a local culture products representing local culture, it can perform an important role on one of the strategies for revitalizing local economy. One of the typical cultures in Kyung-Nam is the Gaya culture. The most characteristic of the Gaya culture is powerful iron culture and lots of cultural properties have been founding as relics. Judging from a lot of iron relics, we can figure out a high level of iron manufacturing technology. I studied focussing on the plasticity of Gaya relics and collected base materials for developing local cultural goods, using the motif of Gaya culture with excellent aesthetic consciousness. I classfied Gaya relics into a crown style, jewelry, harnessry, weapons, armor, earthenware, and considered its characteristic of the plastic arts, based on the preceding studies and document data. There exists natural, moderate, polished, indigenous, simple, rhythmical, delicate, florid, technical, symbolical, strong, diverse, naive beauty in the plastic characteristic of Gaya relics. Gaya culture with the special excellence of aesthetic resources, is worthy enough to be recreated as local cultural goods. Variable and special cultural fashion-products with the distinctive feature of Gaya culture need to be developed without delay.

Study of the FireFighting publicity Satisfaction and an Estimate of the Effects (소방홍보 만족도와 효과측정에 대한 연구)

  • Jeong, Mu Heon;Park, In-seon
    • Fire Science and Engineering
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    • v.31 no.2
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    • pp.101-105
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    • 2017
  • This study examined the firefighting publicity satisfaction (FFPS) and the effects of firefighting publicity (EOFFP) on efficient firefighting publicity (FFP). In addition, the relationship between FFPS and EOFFP was analyzed. The result of the investigation of the FFPS was 58.5 points, which was slightly higher than the medium. The result of EOFFP revealed an increase in fire safety consciousness. In particular, the fire extinguishing ability was higher than the other item. The most powerful FFP method in raising fire safety consciousness was the Internet/Smart phone. Another effective and favorite method of FFP was the media. Fire safety consciousness did not influence the FFPS but the FFPS had an impact on the EOFFP.

Antimicrobial Cyclic Peptides for Plant Disease Control

  • Lee, Dong Wan;Kim, Beom Seok
    • The Plant Pathology Journal
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    • v.31 no.1
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    • pp.1-11
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    • 2015
  • Antimicrobial cyclic peptides derived from microbes bind stably with target sites, have a tolerance to hydrolysis by proteases, and a favorable degradability under field conditions, which make them an attractive proposition for use as agricultural fungicides. Antimicrobial cyclic peptides are classified according to the types of bonds within the ring structure; homodetic, heterodetic, and complex cyclic peptides, which in turn reflect diverse physicochemical features. Most antimicrobial cyclic peptides affect the integrity of the cell envelope. This is achieved through direct interaction with the cell membrane or disturbance of the cell wall and membrane component biosynthesis such as chitin, glucan, and sphingolipid. These are specific and selective targets providing reliable activity and safety for non-target organisms. Synthetic cyclic peptides produced through combinatorial chemistry offer an alternative approach to develop antimicrobials for agricultural uses. Those synthesized so far have been studied for antibacterial activity, however, the recent advancements in powerful technologies now promise to provide novel antimicrobial cyclic peptides that are yet to be discovered from natural resources.