• Asia pacific journal of information systems
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• v.16 no.3
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• pp.159-176
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• 2006

Collaborative filtering is one of the popular techniques for personalized recommendation in e-commerce. In collaborative filtering, user profiles are usually managed per product category in order to reduce data sparsity. Product diversification of Internet storefronts and multiple product category sales of e-commerce portals require cross-product category usage of user profiles in order to overcome the cold start problem of collaborative filtering. In this paper, we study the feasibility of cross-product category usage of user profiles, and suggest a method to improve recommendation performance of cross-product category user profiling. First, we investigate whether user profiles on a product category can be used to recommend products in other product categories. Furthermore, a way of utilizing user profiles selectively is suggested to increase recommendation performance of cross-product category user profiling. The feasibility of cross-product category user profiling and the usefulness of the proposed method are tested with real click stream data of an Internet storefront which sells multiple product categories including books, music CDs, and DVDs. The experiment results show that user profiles on a product category can be used to recommend products in other product categories. Also, the selective usage of user profiles based on correlations between subcategories of two product categories provides better performance than the whole usage of user profiles.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.4
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• pp.154-163
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• 2017

Collaborative filtering, one of the most widely used techniques to build recommender systems, is based on the idea that users with similar preferences can help one another find useful items. Credit card user behavior analytics show that most customers hold three or less credit cards without duplicates. This behavior is one of the most influential factors to data sparsity. The 'cold-start' problem caused by data sparsity prevents recommender system from providing recommendation properly in the personalized credit card recommendation scenario. We propose a personalized credit card recommender system to address the cold-start problem, using multiple user profiles. The proposed system consists of a training process and an application process using five user profiles. In the training process, the five user profiles are transformed to five user networks based on the cosine similarity, and an integrated user network is derived by weighted sum of each user network. The application process selects k-nearest neighbors (users) from the integrated user network derived in the training process, and recommends three of the most frequently used credit card by the k-nearest neighbors. In order to demonstrate the performance of the proposed system, we conducted experiments with real credit card user data and calculated the F1 Values. The F1 value of the proposed system was compared with that of the existing recommendation techniques. The results show that the proposed system provides better recommendation than the existing techniques. This paper not only contributes to solving the cold start problem that may occur in the personalized credit card recommendation scenario, but also is expected for financial companies to improve customer satisfactions and increase corporate profits by providing recommendation properly.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.746-749
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• 2003

Alignment of 2D-gel images of biological samples can visualize the difference of expression profiles and also inform us candidates of protein spots to be further analyzed. However, comparison of two proteome images between case and control does not always successfully identify differentially expressed proteins due to sample-to-sample variation. Because of poor reproducibility of 2D-gel electrophoresis, sample-by-sample variations and inconsistent electrophoresis conditions, multiple number of 2D-gel image must be processed to align each other to visualize the difference of expression profiles and to deduce the protein spots differentially expressed with reliability. Alignment of multiple 2D-Gel images and their clustering were carried out by applying various algorithms and statistical methods. In order to align multiple images, multiresolution-multilevel algorithm was found out to be suitable for fast alignment and for distorted images. Clustering of 12 different images implementing a k-means algorithm gives a phylogenetic tree of distance map of the proteomes. Microsoft Visual C++ was used to implement the algorithms in this work.

• BMB Reports
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• v.33 no.5
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• pp.412-416
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• 2000

The obligate aerobic Deinococcus are highly resistant against lethal effect of UV-and ionizing-radiation. Only five mesophilic Deinococcus species, i. e. D. radiodurans, D. radiophilus, D. proteolyticus, D. radiopugnans, and D. grandis are known. Since an indispensable role of catalase has been suggested in protecting cells against oxidative stress and UV radiation, Deinococcal catalase activity of each species and electrophoretic profiles of catalases were investigated on gel. Total catalase activity was varied among the species in the aerobically grown culture at stationary phase. The occurrence of multiple forms of catalases with different molecular weights in four species of Deinococcus and of a single catalase in D. radiopugnans suggests that each species shows the unique catalase profiles on gel. Some Deinococcal catalases also exhibit peroxidase activity. Since Deinococcus spp. are less-distinct to each other in their morphology, biochemical and physiological properties, the catalase profiles on PAGE would be useful in identifying the species of Deinococcus.

• Bulletin of the Korean Chemical Society
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• v.20 no.6
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• pp.705-711
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• 1999

The laser-induced transient grating method is applied to study the dynamics of the nematic MBBA film. The nanosecond laser pulses of 355 nm are used to make the transient grating and the cw He-Ne laser of 633 nm is used to probe the dynamics. Strong multiple order diffractions are observed at high nematic temperatures. The reordering process induced by the phototransformed state, which is the locally melted state from the nematic sample, is attributed to the main origin of the multiple order diffractions from the nematic MBBA. The characteristics of the multiple order gratings are discussed with the grating profiles simulated from the multiple diffraction signals.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.5
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• pp.47-56
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• 1999

Tensile energy absorption in paper has long been measured as the area under the load-elongation curve. Little effort has been made to define where and how that energy is used within the paper itself. Characterization of tensile energy absorption in paper is discussed. Multiple small elements within newsprint and kraft sack have been defined and the energy absorbed in those elements are discussed. The tensile profiles of the weak paper, newsprint, and the tough paper, kraft sack, are presented as separate strain profiles, stress profiles, and strain energy density profiles. This allows a complete analysis of the energy absorption of both papers for comparison or contrast.

• Journal of Microbiology
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• v.39 no.3
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• pp.232-235
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• 2001

Electrophoretic resolution of superoxide dismutase (SOD) from the highly UV-resistant bacteria, Deinococcus species revealed multiple forms of superoxide dismutases (SODs) in D. radiodurans, D. grandis, and D. proteolyticus, as judged from electrophoretic properties and metal cofactors. A single SOD occurred in both D. radiophilus and D. radiopugnans. Deinococcal SODs were either MnSOD, FeSOD or cambialistic Mn/FeSOD. The unique SOD profile of each mesophilic Deinococcus species, multiplicity and metal cofactors would be valuable in identifying Deinococcus species.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.3
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• pp.292-299
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• 2013

The measurement in the manufacturing process of curved ship hull plates still depends on wooden templates as a standard instrument. The metrology-enabled automation in the shipbuilding process has been challenged instead of line measurement with wooden templates. The developed measurement system consists of a CCD camera, multiple structured laser sources and 3-DOF motion device. The system carries out measurement of curved profiles for large scale plates by an optical triangulation method. The results of experiment conducted in a manufacturing shop demonstrate the accurate and robust performance.

• Communications for Statistical Applications and Methods
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• v.27 no.2
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• pp.241-254
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• 2020

This study proposes generalized models of joint latent class analysis (JLCA) for longitudinal data in two approaches, a JLCA with latent profile (JLCPA) and a JLCA with latent transition (JLTA). Our models reflect cross-sectional as well as longitudinal dependence among multiple latent classes and track multiple class-sequences over time. For the identifiability and meaningful inference, EM algorithm produces maximum-likelihood estimates under local independence assumptions. As an empirical analysis, we apply our models to track the joint patterns of adolescent depression and anxiety among US adolescents and show that both JLCPA and JLTA identify three adolescent emotional well-being subgroups. In addition, JLCPA classifies two representative profiles for these emotional well-being subgroups across time, and these profiles have different tendencies according to the parent-adolescent-relationship subgroups.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.51-54
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• 2008

Various types of beam distributions of high energy lasers are classified by the mode patterns. We study two dimensional laser initiation of confined energetic materials with multiple beam profiles.