1,349 research outputs found
Method For Detecting Shilling Attacks In E-commerce Systems Using Weighted Temporal Rules
The problem of shilling attacks detecting in e-commerce systems is considered. The purpose of such attacks is to artificially change the rating of individual goods or services by users in order to increase their sales. A method for detecting shilling attacks based on a comparison of weighted temporal rules for the processes of selecting objects with explicit and implicit feedback from users is proposed. Implicit dependencies are specified through the purchase of goods and services. Explicit feedback is formed through the ratings of these products. The temporal rules are used to describe hidden relationships between the choices of user groups at two consecutive time intervals. The method includes the construction of temporal rules for explicit and implicit feedback, their comparison, as well as the formation of an ordered subset of temporal rules that capture potential shilling attacks. The method imposes restrictions on the input data on sales and ratings, which must be ordered by time or have timestamps. This method can be used in combination with other approaches to detecting shilling attacks. Integration of approaches allows to refine and supplement the existing attack patterns, taking into account the latest changes in user priorities
Transportation Management in a Distributed Logistic Consumption System Under Uncertainty Conditions
The problem of supply management in the supplier-to-consumer logistics transport system has been formed and solved. The novelty of the formulation of the problem consists in the integrated accounting of costs in the logistic system, which takes into account at the same time the cost of transporting products from suppliers to consumers, as well as the costs for each of the consumers to store the unsold product and losses due to possible shortages. The resulting optimization problem is no longer a standard linear programming problem. In addition, the work assumes that the solution of the problem should be sought taking into account the fact that the initial data of the problem are not deterministic. The analysis of traditional methods of describing the uncertainty of the source data. It is concluded that, given the rapidly changing conditions for the implementation of the delivery process in a distributed supplier-to-consumer system, it is advisable to move from a theoretical probability representation of the source data to their description in terms of fuzzy mathematics. At the same time, in particular, the fuzzy values of the demand for the delivered product for each consumer are determined by their membership functions.Distribution of supplies in the system is described by solving a mathematical programming problem with a nonlinear objective function and a set of linear constraints of the transport type. In forming the criterion, a technology is used to transform the membership functions of fuzzy parameters of the problem to its theoretical probabilistic counterparts – density distribution of demand values. The task is reduced to finding for each consumer the value of the ordered product, minimizing the average total cost of storing the unrealized product and losses from the deficit. The initial problem is reduced to solving a set of integral equations solved, in general, numerically. It is shown that in particular, important for practice, particular cases, this solution is achieved analytically.The paper states the insufficient adequacy of the traditionally used mathematical models for describing fuzzy parameters of the problem, in particular, the demand. Statistical processing of real data on demand shows that the parameters of the membership functions of the corresponding fuzzy numbers are themselves fuzzy numbers. Acceptable mathematical models of the corresponding fuzzy numbers are formulated in terms of bifuzzy mathematics. The relations describing the membership functions of the bifuzzy numbers are given. A formula is obtained for calculating the total losses to storage and from the deficit, taking into account the bifuzzy of demand. In this case, the initial task is reduced to finding the distribution of supplies, at which the maximum value of the total losses does not exceed the permissible value
Assessing Descriptive Substance in Free-Text Collection-Level Metadata
Collection-level metadata has the potential to provide important information about the features and purpose of individual collections. This paper reports on a content analysis of collection records in an aggregation of cultural heritage collections. The findings show that the free-text Description field often provides more accurate and complete representation of subjects and object types than the specified fields. Properties such as importance, uniqueness, comprehensiveness, provenance, and creator are articulated, as well as other vital contextual information about the intentions of a collector and the value of a collection, as a whole, for scholarly users. The results demonstrate that the semantically rich free-text Description field is essential to understanding the context of collections in large aggregations and can serve as a source of data for enhancing and customizing controlled vocabulariesIMLS NLG Research and Demonstration grant LG-06-07-0020-07published or submitted for publicationis peer reviewe
Free-Text Collection-Level Subject Metadata in Large-Scale Digital Libraries: A Comparative Content Analysis
Metadata is central for information organization in digital libraries. A growing number of digital libraries worldwide are now generating metadata to describe not only individual objects but entire digital collections as integral wholes. However, collection-level metadata has not yet been empirically evaluated. This paper reports results of the study that used an in-depth comparative content analysis to assess free-text collection-level subject metadata in three large-scale digital cultural heritage aggregations in the United States and Europe. As observed by this study, the emerging best practices include encoding a variety of information about a digital collection in free-text collection-level Description metadata element. This includes both subject-specific (topical, geographic and temporal coverage, and types/genres of objects in a digital collection) and non-subject-specific information: title, size, provenance, collection development, copyright, audience, navigation and functionality, language of items in a digital collection, frequency of additions, institutions that host a digital collection or contribute to it, funding sources, item creators, importance, uniqueness, and comprehensiveness of a digital collection
The interaction of polymer dispersed liquid crystal sensors with ultrasound
Polymer dispersed liquid crystals (PDLCs) have been shown to be sensitive to ultrasound through the acousto-optic effect. The acousto-optic response of PDLCs was studied over a broad frequency range (0.3–10 MHz). We demonstrate that the displacements required to produce acousto-optic clearing of PDLC films can be as low as a few nanometers, which is at least 103 times smaller than the PDLC droplet size, is 105 times smaller than the PDLC layer thickness, and of the order of the molecular size of the liquid crystal constituents. This suggests that the acousto-optic effect in PDLCs is due to the microscopic effects of the LC reorientation under torques or flows rather than the LC reorientation through macroscopic droplet deformation. The displacement required for clearing is related to the frequency of operation via an exponential decay. We attribute the observed frequency response to a freezing out of the rotational motion around the short axis of the liquid crystal. The reported frequency dependence and displacements required indicate that the effects and materials described here could be used for ultrasound visualization in a non-destructive testing context
The Early Spring Synusias in the Forests of Fageto-carpineto-querceta Roboris Subformation on the Territory of Precarpathian Region (Ukraine)
. In the article were presented the results of studying the early spring synusias in the forests of Fageto-Carpineto-Querceta roboris subformation on the Pricarpathian territory. In the studied subformation were separated five associations: Fageto-Carpineto-Quercetum roboris galiosum odorati, Fageto-Carpineto-Quercetum roboris caricetum pilosae, Fageto-Carpineto-Quercetum roboris vincosum, Fageto-Carpineto-Quercetum roboris galeobdolosum, Fageto-Carpineto-Quercetum roboris hederosum. The revealed early spring synusias are formed by the following herbal species: Leucojum vernum L. (Amaryllidacea), Galanthus nivalis L. (Amaryllidacea), Dentaria glandulosa Waldst. et Kit. (Brassicaceae), Anemone nemorosa L.(Ranunculaceae), Scilla bifolia L. (Liliaceae), Isopyrum thalictroides L. (Ranunculaceae), Corydalis cava (L.) Schweigg. Koerte (Papaveraceae) та Gagea lutea (L.) Ker.-Gawl. (Liliaceae). It appears before the leaves blooming and forms the specific white-lilac-blue aspect. Galanthus nivalis L. synusias develops the first and then in the third decade of March develops the group with Anemone nemorosa L. domination. Last years as the result of the negative anthropogenic influence the number of Leucojum vernum L. and Galanthus nivalis L. groups – the rare ephemeroids put to the Ukrainian Red book was abruptly shortened
The teoretical aspects of integration of students with dissabilities of higher education institution educational environment.
У статті подається теоретичний аналіз підходів учених до проблеми інтеграції студентів з обмеженими можливостями у навчально-виховне середовище вищого навчального закладу. The article presents a theoretical analysis of approaches to the problem of integrating of students with disabilities into the educational environment of higher
education institution.Роботу виконано на кафедрі соціальної педагогіки
ВНУ ім. Лесі УкраїнкиБартків Оксана Степанівна - кандидат педагогічних наук, доцент кафедри соціальної педагогіки інституту педагогіки Східноєвропейського національного університету імені Лесі Українки
Дурманенко О. Л. - аспірантка Східноєвропейського національного університету імені Лесі Українк
Skill-Building in Online Metadata Instruction: Quality Evaluation of Student-Created Metadata Records
As metadata quality directly affects access to information, training LIS students to create
high-quality metadata is an important task. To provide an effective training, a vision is needed
for where best to focus the efforts. That vision should be informed by empirical data on the
common quality problems in student-created metadata records in relation to the content and
methods of instruction. We attempt to address this need through an overview of the metadata
creation skill-building content of the online introductory graduate metadata course, results of the
analysis of quality in student-created metadata records, and discussion of how the observed
common metadata quality issues might inform curriculum development
Complex of Chemical-technological and Sanitary-hygienic Quality Indicators of the New Pastry Products of Special Nutrition
The complex of chemical-technological and sanitary-hygienic quality indicators of new pastry products of special nutrition was studied. The original recipes of meat pastries for special nutrition, enriched with biologically active components at the expanse of vitaminized blended vegetable oils (VBVO) and protein-fatty emulsions (PFE) on their base, were elaborated. There were elaborated four recipes of pastries of chicken and Turkey with PFE, included in recipes in the amount 15…20 % and with vitaminized blended vegetable oils of two-component and three-component composition in the amount 10 %. Pastry samples, prepared according to SSTC 4432:2005 were used as a control.VBVO composition and fat-soluble vitamins content in them was determined by the gasochromatographic method.Molecular-genetic methods were used for the accelerated diagnostics of pastries safety by agents of food intoxications– Clostridium perfringens and Bacillus cereus, number of mesophyl aerobic and facultative-anaerobic microorganisms (NMAFAnM), classic ones – colon bacillus group bacteria (CBGB), sulphite reductive clostridia, Staphylococcus aureus, L.monocytogenes, Salmonella. The storage term of products was prolonged in 2 times (48 against 24 hours) according to SSTC). The expedience of their introduction in production was proved
Питання української культурної спадщини в публіцистиці Дмитра Павличка
У статті йдеться про питання, які піднімає у своїх публіцистичний статтях
Д. Павличко, а саме проблему художньої майстерності, ролі й місця митця в суспільстві, відчуття літературного процесу, впливу творчості однієї людини на творчу долю іншої, проблему молодих письменників.
The article is about the guestions, which D.Pavlychko get up’s in his publicistic articles. Namely, the problem of artistic mastery, the role and place of writer in society, the feeling of literary process, the influence of one person on creative fate of another and the problem of young writers
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