• Title/Summary/Keyword: grouped data

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In-depth Understanding of STEM Information Needs using FGI

  • Park, Minsoo
    • International Journal of Advanced Culture Technology
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    • v.8 no.3
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    • pp.280-284
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    • 2020
  • In the rapidly changing science and technology environment, an in-depth understanding of users of STEM information is an essential factor in designing a user-centered information system. The purpose of this study is to investigate and analyze in-depth the behaviors and needs of users who use STEM information. In this study, the needs of users for STEM information and STEM information sites are dealt with in depth using the FGI qualitative method. In addition, it includes the analysis results of grouping of similar sites according to various aspects of use of STEM information sites. As a result of grouping similar sites based on awareness and level of use,, they were grouped by domestic-international, paid-free, integrated-specific fields. As a result of grouping similar sites according to the purpose of use, they were grouped by domestic and international papers, research reports, and patents. As a result of grouping similar sites according to usage attributes, they were grouped by diversity, reliability, and specialization. As for the positions of similar sites perceived by users, Science Direct and PubMed showed high specialization and high quality, Google Scholar showed integration and popularity, and RISS showed four attributes evenly. Suggestions for information system design are discussed.

Power Failure Sensitivity Analysis via Grouped L1/2 Sparsity Constrained Logistic Regression

  • Li, Baoshu;Zhou, Xin;Dong, Ping
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.8
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    • pp.3086-3101
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    • 2021
  • To supply precise marketing and differentiated service for the electric power service department, it is very important to predict the customers with high sensitivity of electric power failure. To solve this problem, we propose a novel grouped 𝑙1/2 sparsity constrained logistic regression method for sensitivity assessment of electric power failure. Different from the 𝑙1 norm and k-support norm, the proposed grouped 𝑙1/2 sparsity constrained logistic regression method simultaneously imposes the inter-class information and tighter approximation to the nonconvex 𝑙0 sparsity to exploit multiple correlated attributions for prediction. Firstly, the attributes or factors for predicting the customer sensitivity of power failure are selected from customer sheets, such as customer information, electric consuming information, electrical bill, 95598 work sheet, power failure events, etc. Secondly, all these samples with attributes are clustered into several categories, and samples in the same category are assumed to be sharing similar properties. Then, 𝑙1/2 norm constrained logistic regression model is built to predict the customer's sensitivity of power failure. Alternating direction of multipliers (ADMM) algorithm is finally employed to solve the problem by splitting it into several sub-problems effectively. Experimental results on power electrical dataset with about one million customer data from a province validate that the proposed method has a good prediction accuracy.

Time series regression model for forecasting the number of elementary school teachers (초등학교 교원 수 예측을 위한 시계열 회귀모형)

  • Ryu, Soo Rack;Kim, Jong Tae
    • Journal of the Korean Data and Information Science Society
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    • v.24 no.2
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    • pp.321-332
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    • 2013
  • Because of the continuous low birthrates, the number of the elementary students will decrease by 17% in 2020 compared to 2011. The purpose of this study is to forecast the number of elementary school teachers until 2020. We used the data in education statistical year books from 1970 to 2010. We used the time-series regression model, time series grouped regression model and exponential smoothing model to predict the number of teachers for the next ten years. Consequently time-series grouped regression model is a better model for forecasting the number of elementary school teachers than other models.

Parameters Estimators for the Generalized Exponential Distribution

  • Abuammoh, A.;Sarhan, A.M.
    • International Journal of Reliability and Applications
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    • v.8 no.1
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    • pp.17-25
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    • 2007
  • Maximum likelihood method is utilized to estimate the two parameters of generalized exponential distribution based on grouped and censored data. This method does not give closed form for the estimates, thus numerical procedure is used. Reliability measures for the generalized exponential distribution are calculated. Testing the goodness of fit for the exponential distribution against the generalized exponential distribution is discussed. Relevant reliability measures of the generalized exponential distributions are also evaluated. A set of real data is employed to illustrate the results given in this paper.

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Non-parametric approach for the grouped dissimilarities using the multidimensional scaling and analysis of distance (다차원척도법과 거리분석을 활용한 그룹화된 비유사성에 대한 비모수적 접근법)

  • Nam, Seungchan;Choi, Yong-Seok
    • The Korean Journal of Applied Statistics
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    • v.30 no.4
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    • pp.567-578
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    • 2017
  • Grouped multivariate data can be tested for differences between two or more groups using multivariate analysis of variance (MANOVA). However, this method cannot be used if several assumptions of MANOVA are violated. In this case, multidimensional scaling (MDS) and analysis of distance (AOD) can be applied to grouped dissimilarities based on the various distances. A permutation test is a non-parametric method that can also be used to test differences between groups. MDS is used to calculate the coordinates of observations from dissimilarities and AOD is useful for finding group structure using the coordinates. In particular, AOD is mathematically associated with MANOVA if using the Euclidean distance when computing dissimilarities. In this paper, we study the between and within group structure by applying MDS and AOD to the grouped dissimilarities. In addition, we propose a new test statistic using the group structure for the permutation test. Finally, we investigate the relationship between AOD and MANOVA from dissimilarities based on the Euclidean distance.

Factor Analysis of the Seawater Quality of the Southern Coastal Waters of Korea

  • Lee Yong-Hwan;Jung Kyoo-Jin;Kim Hak-Kook
    • Fisheries and Aquatic Sciences
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    • v.6 no.3
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    • pp.140-148
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    • 2003
  • On the basis of factor analysis, stations were grouped according to their similar characteristics of seawater quality. The data for factor analysis were collected from the 15 stations from Dukryang Bay to Ulsan Bay on the southern cost of Korea. The study was based on the data from 1991 to 2000. The 8 water quality items analyzed were temperature, salinity, pH, DO, COD, DIN (dissolved inorganic nitrogen), DIP (dissolved inorganic phosphorus), and SS (suspended solid). Analysis of 6 water quality items including DO with the exception of temperature and salinity showed that 15 stations were grouped into two zones, i.e., the western and the eastern coast, by the axis of Samcheonpo-Jinju Bay-south of Geoje, 3 seawater zones in all. The adjacent stations to the southward or northward but not those to the eastward or westward were classified into the same group. On the analysis of all of the 8 water quality items, the stations of Dukryang Bay and Goheung; and those of Onsan and Ulsan Bay were classified into the same group. Yeosu and Namhae stations were sectioned into 1 group on the all seawater quality items but DIP, Samcheonpo and south of Geoje stations another group on all seawater quality items but water temperature, and Masan and Busan stations in the other group on all seawater quality items but DO. The stations from Dukryang Bay through Goheung to east of Geoje were grouped together on the COD item, and this showed somewhat different tendency in other seawater quality items.

Classification of the General Hospital Employees according to Information Requirements (정보 요구에 따른 종합 병원 종사자들의 분류)

  • 박찬석;고석하
    • Journal of Information Technology Applications and Management
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    • v.10 no.2
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    • pp.43-59
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    • 2003
  • In this study the information requirements of the personnel of Korean general hospitals are investigated. The results of the survey reveal that the information requirements of the general hospital personnel are quite different from each other according to their occupation type. The results show that the integrity of information about patients and the pervasiveness of information regarding to overall hospital operations are two major factors that differentiates the information requirements variation among occupation types of general hospital personnel. The results show that doctors, nurses, and medical technologists can be grouped into a occupation group, and that the admission department personnel and the patient affairs personnel can be grouped into another group. The results also show pharmacists and nutrition technicians constitute separate occupation groups of their own, respectively.

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Evaluation of Genetic Diversity among Korean Wild Codonopsis lanceolata by Using RAPD

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    • Korean Journal of Plant Resources
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    • v.10 no.3
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    • pp.258-264
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    • 1997
  • The introduction of molecular biology methodologies to plant improvement programs offers an invaluable opportunity for extensive germplasm characterization. We have applied the developed technique of random amplification of polymorphic DNA(RAPD)to the analysis of evaluating genetic diversity among Korean wild Codonopsis lanceolata. A total of 340 polymorpic hands were gernerated on agarose- and polyacrylamide-gel by 19 primers of abitrary sequence. grouped by cluster analysis using sample matching coefficients of similarity. Among of the samples. the minimum genetic distance value was obtained between sample no. 1(Girisan) and no. 2(Girisan), and the largest value between sample no. 11(Sulaksan) and no. 17(Sulaksan).In separate cluster dendrograms based on agareose - and polyacryamide-gel. some differences were observed; In the case of agarose gel,41 samples could be devided into 7 groups at below about 0.44 level of distance. However they were divided into 6 gourps at below about 0.40 level of distance in the case of polyacrylamide gel. These results showed that polymophic data in agrose were not grouped to wild plant selected from each mountainous district except for wild plants selected from Sulaksan and Chiaksan. We believe that polyacrylamide-RAPD is a superior method for detecting DNA polymorphism compared to agarose-RAPD method.

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Vegetative Compatibility Groups and Virulence Variation Among Isolates of Pyrenophora graminea

  • Arabi, Mohammad Imad Eddin;Jawhar, Mohammad
    • The Plant Pathology Journal
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    • v.27 no.2
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    • pp.116-119
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    • 2011
  • Pyrenophora graminea, the causal agent of leaf stripe disease, is an economically important pathogen of barley found worldwide. Forty-four isolates of diverse geographical origin within Syria were grouped into vegetative compatibility groups (VCGs) by demonstrating heterokaryosis by complementation tests using nitrate nonutilizing (nit) mutants. All isolates were grouped into three VCGs-1-A, 1-B and 1-C. No self-incompatibility was observed in any of the isolates tested. VCG 1-A was the most common group within growing regions in Syria and proved to be the most virulent of the VCGs identified. These data indicate that the level of virulence in P. graminea is related to VCG.

A Comparative Analysis on Page Caching Strategies Affecting Energy Consumption in the NAND Flash Translation Layer (NAND 플래시 변환 계층에서 전력 소모에 영향을 미치는 페이지 캐싱 전략의 비교·분석)

  • Lee, Hyung-Bong;Chung, Tae-Yun
    • IEMEK Journal of Embedded Systems and Applications
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    • v.13 no.3
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    • pp.109-116
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    • 2018
  • SSDs that are not allowed in-place update within the allocated page cause another allocation of a new page that will replace the previous page at the moment data modification occurs. This intrinsic characteristic of SSDs requires many changes to the existing HDD-based IO theory. In this paper, we conduct a performance comparison of FTL caching strategy in perspective of cache hashing (Global vs. grouped) and caching algorithm (LRU vs. NUR) through a simulation. Experimental results show that in terms of energy consumption for flash operation the grouped management of cache is not suitable and NUR algorithm is superior to LRU algorithm. In particular, we found that the cache hit ratio of LRU algorithm is about 10% point higher than that of NUR algorithm while the energy consumption of LRU algorithm is about 32% high.