• Title/Summary/Keyword: separation and sorting

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Cryo-Ability of Boar Sperm sorted by Percoll Containing of Antioxidative Enzyme (항산화 효소가 첨가된 Percoll에 의해 분리한 돼지 정액의 동결-융해 능력)

  • Lee, Kyung-Jin;Lee, Sang-Hee;Joo, Seon-Ho;Kim, Yu-Jin;Yang, Jin-Woo;Lee, Yeon-Ju;Hwangbo, Yong;Lee, Seunghyung;Lee, Seung Tae;Lee, Eunsong;Park, Choon-Keun
    • Journal of Embryo Transfer
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    • v.30 no.3
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    • pp.121-128
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    • 2015
  • The objective of this study was to evaluate the efficiency of sperm cryosurvival in boar sperm separated by Percoll containing antioxidant enzymes. The boar semen was collected into a pre-warmed ($37^{\circ}C$) thermos bottle by gloved-hand method and was separated by 65% Percoll with superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) before freezing. The frozen sperm was thawed at $38.5^{\circ}C$ for 45 sec in water-bath for sperm characteristic analysis. The sperm were estimated with SYBR14/PI double staining for viability, FITC-PNA/PI double staining for acrosome reaction, Rhodamine123/PI double staining for mitochondrial integrity and were analyzed using flow cytometry. In results, sperm viability, acrosome reaction and mitochondrial integrity were improved in separated sperm groups compared with unseparated sperm by Percoll (UP) group. Especially, viability was significantly higher in sperm separated by Percoll containing 400 IU CAT group compared with other groups (P<0.05). And acrosome reaction was decreased in sperm separated by Percoll with 300 IU SOD, 400 IU CAT and 0.5 mM GSH groups compared with other groups, however, there were no significantly difference mitochondrial integrity among sperm separated by Percoll with antioxidant enzymes. In conclusion, we suggest that use of Percoll containing antioxidant enzymes for sperm separation will be beneficial for sperm cryopreservation in pigs.

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.