Processing count queries over event streams at multiple time granularities

Cataloged from PDF version of article.Management and analysis of streaming data has become crucial with its applications to web, sensor data, network traffic data, and stock market. Data streams consist of mostly numeric data but what is more interesting are the events derived from the numerical data that need to be monitored. The events obtained from streaming data form event streams. Event streams have similar properties to data streams, i.e., they are seen only once in a fixed order as a continuous stream. Events appearing in the event stream have time stamps associated with them at a certain time granularity, such as second, minute, or hour. One type of frequently asked queries over event streams are count queries, i.e., the frequency of an event occurrence over time. Count queries can be answered over event streams easily, however, users may ask queries over different time granularities as well. For example, a broker may ask how many times a stock increased in the same time frame, where the time frames specified could be an hour, day, or both. Such types of queries are challenging especially in the case of event streams where only a window of an event stream is available at a certain time instead of the whole stream. In this paper, we propose a technique for predicting the frequencies of event occurrences in event streams at multiple time granularities. The proposed approximation method efficiently estimates the count of events with a high accuracy in an event stream at any time granularity by examining the distance distributions of event occurrences. The proposed method has been implemented and tested on different real data sets including daily price changes in two different stock exchange markets. The obtained results show its effectiveness. (C) 2005 Elsevier Inc. All rights reserved

Research on the efficiency and performance of camera traps and dome system for wild goat inventory

This study, carried out in 2009-2010, aims to use imaging technology for wild goat inventory in the study area, because direct counts done by means of labor intensive techniques give high error rates. Camera traps and dome systems are used to investigate the replacement of direct counts done by authorized institutions, using manpower in vast and rough terrains for Capra aegagrus. In a total area of 555 hectares, of which 50 were for establishing dome and camera traps, the monitoring system recorded images in predefined hours (07.00 to 09.00; 17.00 to 19.00). These periods also coincide with the selected hours for point counts during periodical inventories for wild goat by the relevant official department. The group size of wild goat was determined as 18. 1, which was captured by the dome camera or camera traps. While dome camera system was not able to monitor the entire group, significant information on the number of the wild goats was via camera system. As a result, if used together, camera traps and dome camera system could contribute effectively to wildlife inventory work, providing 70% of the need for the inventory. The study has shown that it is possible to transfer load of manmade inventory to technology and to achieve much more economical inventories by eliminating the risks and disadvantages caused by human factorKey words: Wild goat (Capra aegagrus), inventory, direct counts, camera traps, dome system

QR-RLS algorithm for error diffusion of color images

Printing color images on color printers and displaying them on computer monitors requires a significant reduction of physically distinct colors, which causes degradation in image quality. An efficient method to improve the display quality of a quantized image is error diffusion, which works by distributing the previous quantization errors to neighboring pixels, exploiting the eye's averaging of colors in the neighborhood of the point of interest. This creates the illusion of more colors. A new error diffusion method is presented in which the adaptive recursive least-squares (RLS) algorithm is used. This algorithm provides local optimization of the error diffusion filter along with smoothing of the filter coefficients in a neighborhood. To improve the performance, a diagonal scan is used in processing the image, (C) 2000 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(00)00611-5]

Osteoselection supported by phase separeted polymer blend films

Cataloged from PDF version of article.The instability of implants after placement inside the body is one of the main obstacles to clinically succeed in periodontal and orthopedic applications. Adherence of fibroblasts instead of osteoblasts to implant surfaces usually results in formation of scar tissue and loss of the implant. Thus, selective bioadhesivity of osteoblasts is a desired characteristic for implant materials. In this study, we developed osteoselective and biofriendly polymeric thin films fabricated with a simple phase separation method using either homopolymers or various blends of homopolymers and copolymers. As adhesive and proliferative features of cells are highly dependent on the physicochemical properties of the surfaces, substrates with distinct chemical heterogeneity, wettability, and surface topography were developed and assessed for their osteoselective characteristics. Surface characterizations of the fabricated polymer thin films were performed with optical microscopy and SEM, their wettabilities were determined by contact angle measurements, and their surface roughness was measured by profilometry. Long-term adhesion behaviors of cells to polymer thin films were determined by F-actin staining of Saos-2 osteoblasts, and human gingival fibroblasts, HGFs, and their morphologies were observed by SEM imaging. The biocompatibility of the surfaces was also examined through cell viability assay. Our results showed that heterogeneous polypropylene polyethylene/polystyrene surfaces can govern Saos-2 and HGF attachment and organization. Selective adhesion of Saos-2 osteoblasts and inhibited adhesion of HGF cells were achieved on micro-structured and hydrophobic surfaces. This work paves the way for better control of cellular behaviors for adjustment of cell material interactions. © 2014 Wiley Periodicals, Inc

QR-RLS algorithm for error diffusion of color images

Printing color images on color printers and displaying them on computer monitors requires a significant reduction of physically distinct colors, which causes degradation in image quality. An efficient method to improve the display quality of a quantized image is error diffusion, which works by distributing the previous quantization errors to neighboring pixels, exploiting the eye's averaging of colors in the neighborhood of the point of interest. This creates the illusion of more colors. A new error diffusion method is presented in which the adaptive recursive least-squares (RLS) algorithm is used. This algorithm provides local optimization of the error diffusion filter along with smoothing of the filter coefficients in a neighborhood. To improve the performance, a diagonal scan is used in processing the image

Análisis Político (no. 23 sep-dic 1994)

ESTUDIOS Modernidad, Modernizaciones y Ciencias Sociales MARCO PALACIOS Educación Superior: una condición para la transformación productiva con equidad VÍCTOR MANUEL GÓMEZ CAMPO DEMOCRACIA Movimientos sociales: organización y estructura de oportunidad política MARGARITA BONAMUSA MIRALLES COYUNTURA Los derechos humanos del nuevo gobierno: entre la imagen y la realidad JUAN GABRIEL GÓMEZ ALBARELLO DEBATE ¡A humanizar! GUSTAVO GALLÓN TESTIMONIOS Entrevista a Jean François Lyotard Traducción VÍCTOR FLORIÁN RESEÑAS La muerte anunciada: poder, secreto y violencia en una muerte anunciada de Gabriel García Márquez, DE DANIEL RAMOS por MARÍA EMMA WILLS OBREGÓN Mujeres y participación política. Avances y desafíos en América Latina, DE MAGDALENA LEÓN (Compiladora) SOCORRO RAMÍREZ VARGAS Después del comunismo. La difícil transición en Europa Central y Oriental, DE HUGO FAZIO VENGOA por FRANCISCO GUTIÉRREZ SANÍN BIBLIOGRAFÍA TEMÁTICA Abstención y participación electoral en Colombia y América Latina LINDA HELFRICH AL MARGEN Los escolios de la inteligencia ALEJANDRO REYES POSAD

Análisis Político (no. 21 ene-abr 1994)

ESTUDIOS La hora de la sociedad civil CARLOS M. VILAS El cambio de modelo de desarrollo de la economía colombiana ANDRÉS LÓPEZ RESTREPO DEMOCRACIA Anfibios culturales y divorcio entre ley, moral y cultura ANTANAS MOCKUS SIVICKAS El intervencionismo en la posguerra fría SOCORRO RAMÍREZ VARGAS COYUNTURA Seguridad: ¿para la gente o para el estado? ÁLVARO CAMACHO GUIZADO DEBATE Proceso de paz: ¿se ha nadado contra la corriente? JACINTO RUIZ RESEÑAS La utopía Desarmada, DE JORGE G. CASTAÑEDA JAIME ZULUAGA NIETO La estrategia del Caracol, DE SERGIO CABRERA, WILLIAM RAMÍREZ TOBÓN BIBLIOGRAFÍA TEMÁTICA Género, poder y desarrollo DONNY MEERTEN