• Title/Summary/Keyword: non-standard growth sources

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BLOWUP PROPERTIES FOR PARABOLIC EQUATIONS COUPLED VIA NON-STANDARD GROWTH SOURCES

  • Liu, Bingchen;Hong, Zhenzhen
    • Journal of applied mathematics & informatics
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    • v.31 no.1_2
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    • pp.285-297
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    • 2013
  • This paper deals with parabolic equations coupled via nonstandard growth sources, subject to homogeneous Dirichlet boundary conditions. Three kinds of necessary and sufficient conditions are obtained, which determine the complete classifications for non-simultaneous and simultaneous blowup phenomena. Moreover, blowup rates are given.

Isolation of Environmental Mycobacteria from Diverse Water Samples Using Cetylpyridinium Chloride

  • Choi, Yeon-Im;Jin, Hyun-Woo;Lee, Gyu-Sang;Kim, Jong-Bae;Song, In-Kenn;Kim, Young-Joon;Lee, Hye-Young
    • Biomedical Science Letters
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    • v.16 no.3
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    • pp.133-138
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    • 2010
  • Despite of the increasing importance of environmental mycobacteria, detection and identification of mycobacteria from environmental sources including water have been fraught with technical difficulties. Although, several protocols to optiruize isolation of mycobacteria from water sources have been reported, standard method has not yet been established. In this study, usefulness of cetylpyridinium chloride (CPC), a cationic quaternary ammonium compound, for the isolation of environmental mycobacteria from diverse water samples was evaluated. For this, water samples from diverse water sources such as effluent water, lake water, and underground water were collected, treated with diverse concentrations of CPC, and plated on the solid agar plates. Subsequently individual colonies grown on the plates were sequence analyzed for identification of each colony. In brief, the results from this study showed that the growth of mycobacteria was enhanced by use of CPC as a pre-treatment reagent to water samples by inhibiting growth of other non-mycobacteria in water. In fact, the effect of CPC to decontaminate non-mycobacteria for isolation of mycobacteria was better than 1~4% of NaOH, which is a routinely used decontaminating reagent widely employed for culturing mycobactera from sputum specimens. Therefore, the results from this study seems to support that the CPC pre-treatment may be useful for isolation of mycobacteria from diverse sources including clinical specimens which are often contaminated with other bacteria.

Qualitative Case Study on Life of non-disabled Adolescent of Parents with Intellectual Disability (지적장애 부모를 둔 비장애 청소년의 삶에 관한 질적 사례연구)

  • Kang, Seung Won
    • Korean Journal of Social Welfare
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    • v.68 no.3
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    • pp.73-103
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    • 2016
  • In this study, it investigates the life of normal adolescents who have parents with intellectual disability and their difficulties which suggested social welfare meanings of this study. In order to conduct wide and in-depth analysis on cases by utilizing the characteristics of qualitative case studies, it describes and analyzes the intellectual disability parents' normal children in detail from the viewpoint of an insider through in-depth interviews, various sources and diverse data collecting methods. As for the subject of this study, both parents should be persons with intellectual disability and their child shall be non-disabled and at least a high school student or older. Through the intentional sampling, five late adolescents who were in high school, all males participated in the study. The data collection process had been conducted from January 2014 to May, which is commonly utilized for qualitative case studies, and comparative analysis between cases were practiced for analysis. For credibility of the research results, it obtained severity at each stage by meeting the standard. The analysis results were largely divided into "growth story of non-disabled adolescents" and "life of non-disabled adolescents". Nine upper categories analyzed the common features in each case. The nine categories were "no one tells me to study", "advance while learning the sense of academic achievement", "hide into my own space", "having to grown up early", "different parents but same love", "relatives raised me", "have a friend who accepts me as I am", "being pressed by poverty", and "standing on a knife edge of being hurt and taking heart". Based on the in-depth research on normal teens that have intellectually disabled parents, theoretically speaking, this study expanded the prospect of study on intellectually disabled to their normal, intellectual teenage children. As for practical significance, understanding their parents' intellectual disability, parenting technique training, case management from the community level is suggested. Rregular real condition research of the families, allowance system for economic support et al. is suggested in policy aspect.

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A Study of ePub-based Standard Framework Supporting Mutual Comparability of eBook DRM (전자책 DRM의 상호호환성을 지원하는 ePub 기반 표준 프레임워크에 관한 연구)

  • Kang, Ho-Gap;Kim, Tae-Hyun;Yoon, Hee-Don;Cho, Seong-Hwan
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.11 no.6
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    • pp.235-245
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    • 2011
  • EBooks refer to electronic versions of books which are accessible via internet with forms of digital texts. In recent years, Amazon's Kindle digital eBooks has revealed the possibilities of success of the e-book market, which leads other companies to launch eBook service such as Google's eBook stores and Apple's iPad and eBook service. These reveal that the eBook market is finally showing a substantial amount of growth. Although the issue of technical support of eBook copyright protection emerges from the fast growing eBook marketplace, current technic of commercial DRM for protecting eBook copyright protection still has problems of non-comparability. Therefore, with the current technical status, DRM comparability problems, which have already occurred in music DRM environment, would also happen in eBook environment. This study suggests a standard framework to support eBook DRM comparability. When development of the standard reference software for eBook DRM comparability is completed, the sources will be registered as shareware to be open to public.

Economic Impact Analysis of Hydrogen Energy Deployment Applying Dynamic CGE Model (동태 CGE 모형을 활용한 수소에너지 보급의 경제적 영향 추정)

  • Bae, Jeong-Hwan;Cho, Gyeong-Lyeob
    • Environmental and Resource Economics Review
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    • v.16 no.2
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    • pp.275-311
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    • 2007
  • Hydrogen energy is emphasized as a substitutable energy of carbon-based energy system in the future, since it is non-depletable and clean energy. Long term vision of Korean government on the national energy system is to promote hydrogen energy by 15% of final energy demand until 2040. This study analyzes economic impacts of hydrogen energy development employing a dynamic CGE model for Korea. Frontier technology such as hydrogen energy is featured as slow diffusion at the initial stage due to the learning effect and energy complementarity. Without government intervention, hydrogen energy would be produced upto 6.5% of final energy demand until 2040. However, if government subsidizes sales price of hydrogen energy by 10%, 20%, and 30%, share of hydrogen energy would increase 9.2%, 15.2%, and 37.7% of final energy demand. This result shows that the slow diffusion problem of hydrogen energy as frontier technology could be figured out by market incentive policy. On the other hand, production levels of transportation sector would increase while growth rate of oil and electricity sectors would decline. Household consumption would be affected negatively since increase of consumption due to the price decrease would be overwhelmed by income reduction owing to the increase of tax. Overall, GDP would not decrease or increase significantly since total production, investment, and export would increase even if household consumption declines.

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Potential Contamination Sources on Fresh Produce Associated with Food Safety

  • Choi, Jungmin;Lee, Sang In;Rackerby, Bryna;Moppert, Ian;McGorrin, Robert;Ha, Sang-Do;Park, Si Hong
    • Journal of Food Hygiene and Safety
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    • v.34 no.1
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    • pp.1-12
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    • 2019
  • The health benefits associated with consumption of fresh produce have been clearly demonstrated and encouraged by international nutrition and health authorities. However, since fresh produce is usually minimally processed, increased consumption of fresh fruits and vegetables has also led to a simultaneous escalation of foodborne illness cases. According to the report by the World Health Organization (WHO), 1 in 10 people suffer from foodborne diseases and 420,000 die every year globally. In comparison to other processed foods, fresh produce can be easily contaminated by various routes at different points in the supply chain from farm to fork. This review is focused on the identification and characterization of possible sources of foodborne illnesses from chemical, biological, and physical hazards and the applicable methodologies to detect potential contaminants. Agro-chemicals (pesticides, fungicides and herbicides), natural toxins (mycotoxins and plant toxins), and heavy metals (mercury and cadmium) are the main sources of chemical hazards, which can be detected by several methods including chromatography and nano-techniques based on nanostructured materials such as noble metal nanoparticles (NMPs), quantum dots (QDs) and magnetic nanoparticles or nanotube. However, the diversity of chemical structures complicates the establishment of one standard method to differentiate the variety of chemical compounds. In addition, fresh fruits and vegetables contain high nutrient contents and moisture, which promote the growth of unwanted microorganisms including bacterial pathogens (Salmonella, E. coli O157: H7, Shigella, Listeria monocytogenes, and Bacillus cereus) and non-bacterial pathogens (norovirus and parasites). In order to detect specific pathogens in fresh produce, methods based on molecular biology such as PCR and immunology are commonly used. Finally, physical hazards including contamination by glass, metal, and gravel in food can cause serious injuries to customers. In order to decrease physical hazards, vision systems such as X-ray inspection have been adopted to detect physical contaminants in food, while exceptional handling skills by food production employees are required to prevent additional contamination.

The Prediction of DEA based Efficiency Rating for Venture Business Using Multi-class SVM (다분류 SVM을 이용한 DEA기반 벤처기업 효율성등급 예측모형)

  • Park, Ji-Young;Hong, Tae-Ho
    • Asia pacific journal of information systems
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    • v.19 no.2
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    • pp.139-155
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    • 2009
  • For the last few decades, many studies have tried to explore and unveil venture companies' success factors and unique features in order to identify the sources of such companies' competitive advantages over their rivals. Such venture companies have shown tendency to give high returns for investors generally making the best use of information technology. For this reason, many venture companies are keen on attracting avid investors' attention. Investors generally make their investment decisions by carefully examining the evaluation criteria of the alternatives. To them, credit rating information provided by international rating agencies, such as Standard and Poor's, Moody's and Fitch is crucial source as to such pivotal concerns as companies stability, growth, and risk status. But these types of information are generated only for the companies issuing corporate bonds, not venture companies. Therefore, this study proposes a method for evaluating venture businesses by presenting our recent empirical results using financial data of Korean venture companies listed on KOSDAQ in Korea exchange. In addition, this paper used multi-class SVM for the prediction of DEA-based efficiency rating for venture businesses, which was derived from our proposed method. Our approach sheds light on ways to locate efficient companies generating high level of profits. Above all, in determining effective ways to evaluate a venture firm's efficiency, it is important to understand the major contributing factors of such efficiency. Therefore, this paper is constructed on the basis of following two ideas to classify which companies are more efficient venture companies: i) making DEA based multi-class rating for sample companies and ii) developing multi-class SVM-based efficiency prediction model for classifying all companies. First, the Data Envelopment Analysis(DEA) is a non-parametric multiple input-output efficiency technique that measures the relative efficiency of decision making units(DMUs) using a linear programming based model. It is non-parametric because it requires no assumption on the shape or parameters of the underlying production function. DEA has been already widely applied for evaluating the relative efficiency of DMUs. Recently, a number of DEA based studies have evaluated the efficiency of various types of companies, such as internet companies and venture companies. It has been also applied to corporate credit ratings. In this study we utilized DEA for sorting venture companies by efficiency based ratings. The Support Vector Machine(SVM), on the other hand, is a popular technique for solving data classification problems. In this paper, we employed SVM to classify the efficiency ratings in IT venture companies according to the results of DEA. The SVM method was first developed by Vapnik (1995). As one of many machine learning techniques, SVM is based on a statistical theory. Thus far, the method has shown good performances especially in generalizing capacity in classification tasks, resulting in numerous applications in many areas of business, SVM is basically the algorithm that finds the maximum margin hyperplane, which is the maximum separation between classes. According to this method, support vectors are the closest to the maximum margin hyperplane. If it is impossible to classify, we can use the kernel function. In the case of nonlinear class boundaries, we can transform the inputs into a high-dimensional feature space, This is the original input space and is mapped into a high-dimensional dot-product space. Many studies applied SVM to the prediction of bankruptcy, the forecast a financial time series, and the problem of estimating credit rating, In this study we employed SVM for developing data mining-based efficiency prediction model. We used the Gaussian radial function as a kernel function of SVM. In multi-class SVM, we adopted one-against-one approach between binary classification method and two all-together methods, proposed by Weston and Watkins(1999) and Crammer and Singer(2000), respectively. In this research, we used corporate information of 154 companies listed on KOSDAQ market in Korea exchange. We obtained companies' financial information of 2005 from the KIS(Korea Information Service, Inc.). Using this data, we made multi-class rating with DEA efficiency and built multi-class prediction model based data mining. Among three manners of multi-classification, the hit ratio of the Weston and Watkins method is the best in the test data set. In multi classification problems as efficiency ratings of venture business, it is very useful for investors to know the class with errors, one class difference, when it is difficult to find out the accurate class in the actual market. So we presented accuracy results within 1-class errors, and the Weston and Watkins method showed 85.7% accuracy in our test samples. We conclude that the DEA based multi-class approach in venture business generates more information than the binary classification problem, notwithstanding its efficiency level. We believe this model can help investors in decision making as it provides a reliably tool to evaluate venture companies in the financial domain. For the future research, we perceive the need to enhance such areas as the variable selection process, the parameter selection of kernel function, the generalization, and the sample size of multi-class.