Dynamic Usage Research Articles

Asymmetric effects of dynamic usage behavior on duration in subscription-based online service

In this article, we develop a model to predict the lifetime duration of customers for a subscription-based online content provider. In contrast to prior research, this article employs a dynamic measure of usage and compares alternate model specifications. A proportional hazard model is used with time-varying usage covariates obtained from Web logs while controlling for initial purchase characteristics such as purchase price and billing frequency. We test and find evidence for violation of the proportionality assumption in the hazard model and conclude that a stratified hazard model provides the best model fit. The results show that customers who are billed monthly for annual subscriptions maintain their subscriptions longer than do customers billed quarterly, when compared to annual subscriptions. Furthermore, dynamic changes in usage have an asymmetric effect on duration, with increases in usage having a stronger effect than do decreases in usage. Managers can use this model to identify the customers to be targeted for both retention and upgrade.

Policy Defined Spectrum sharing and medium Access for Cognitive Radios

Spectrum regulation will undergo elementary changes in the near future allowing a less restricted and more flexible access to radio spectrum. Intelligent radios, so- called cognitive radios, will realize the dynamic usage of frequency bands on an opportunistic basis, by identifying and using under-utilized spectrum. Such a flexible spectrum usage requires changes in regulation towards a more open spectrum. Policies which determine when spectrum is considered as opportunity and which define the possibilities of using these spectrum opportunities are needed. First, this article discusses an approach that intends to enable distributed QoS support in open spectrum. This algorithm is specified as policy in a machine-understandable policy description language, such that the cognitive radio is capable of reasoning about spectrum usage. Policies that enable a software defined medium access are the second focus of this article. We discuss a step towards the realization of such cognitive radios at the example of the well-known Enhanced Distributed Channel Access of IEEE 802.11e. This channel access protocol is here specified in a machine understandable policy language, instead of lengthy textual description. Such a machine-understandable description of the protocol enables cognitive radios to operate in distributed environments according to the 802.11(e) standard.

The Use of Dynamic Text in the Communication Process

Principles concerning appropriate sizes, line length and line spacing for reading matter are studied by several researchers (Black, 1990). In practice (White, 2003), the best text type is so comfortable that it is invisible (transparent), i.e. the reader is not aware of the act of reading. The way in which designer uses the space on the page greatly affects how easily the reader can understand and retrieve the information from it (Hartley, 1994). Digital possibilities of connecting spatial with textual data dynamically may guide reader's attention and increase reader's capability of understanding, memorizing and learning textually presented information. The effects of dynamic visuals on information acquisition have been investigated by several researchers (Angelin et al, 1996). Motion typography can convey ideas, aesthetics and evoke responses. The motion variables of dynamic text include alternations of font's proportions, changes over time and changes in motion directions. The research will examine and evaluate possible merits and dangers of dynamic text usage for transparent readability. The aims are to determine relationships between font (type, size), line (length, spacing) and motion (speed, direction) for better readability. Students from The Faculty of Graphic Arts, Graphic Design Department, are chosen as the observers for visual evaluation.

Dynamic usage of transcription start sites within core promoters

An exploration of the internal dynamics of mammalian promoters demonstrates that start site selection within mouse core promoters varies amongst tissues.

Transcription regulation: a genomic network

The transcriptional regulatory system plays a central role in directing gene expression changes in response to internal and external stimuli. In this talk, I will present our group's computational studies on transcription regulation in yeast, ranging from large-scale experimental studies to computational analyses of regulatory networks. In the first half I will introduce results from ChIp-chip experiments that identify genome-wide DNA-binding sites of transcription factors, particularly focusing on the cell cycle regulatory system. In the second half I will discuss how these observations fit in with the idea of a genomic regulatory network, and examine the effects of such networks on gene expression levels. Finally, I will introduce the concept of dynamic network usage in the context of transcription regulation, and how specific regulatory pathways are employed to bring about these transitions.

Presentation and simulation of computer architectures

Understanding modern computer architectures requires a good knowledge of the dynamic behavior of processors. A new alternative platform for creating and delivering presentations that successfully combines positive issues of both general and special-purpose presentation tools for computer architectures is proposed in this paper. Proposed platform introduces the concept of dynamic usage of data providers during the presentation and creating slide templates instead of slide creation. Originally developed presentation/simulation tool SimArch that implements almost all key features from the new platform is described. SimArch is designed for teaching/research purposes and devoted to description and visualization of computer architectures. Crucial novelties in SimArch related to involving of slide templates, behavior cases and selection of examples are demonstrated on examples based on MIPS architecture subsets.

Effects of Mug Book Size and Computerized Pruning on the Usefulness of Dynamic Mug Book Procedures

The usefulness of dynamic mug books with larger sets of mug shots was explored in experiment 1. Participants viewed a videotaped crime and attempted an identification from either a dynamic mug book (computerized video clips could be chosen) or a static mug book. The perpetrator appeared in one of three positions - 70, 140, or 210. When the perpetrator and the 69 preceding foils appeared in positions 1-70, correct identifications and false positives were higher than for later positions. Dynamic information usage decreased so dramatically for the later positions that it was argued that dynamic mug books should be used only when the number of pictures could be pruned. Experiment 2 explored the usefulness of pruning dynamic mug books. Identifications were attempted in mug books that contained either 69 pictures pruned by a computer facial-recognition algorithm for their similarity to the perpetrator, or a random selection of 69 pictures. As in past research, the dynamic mug book reduced false positives; however, in contrast to past research, similarity of mug book pictures as defined by the algorithm did not affect mug book performance. Experiment 3 tested the relationship between the computer facial-recognition algorithm similarity ratings used in experiment 2 with human similarity judgments. No relationship was found between human and computer ratings of similarity.

IMPROVING ENCARTA SEARCH ENGINE PERFORMANCE BY MINING USER LOGS

We propose a data-mining approach that produces generalized query patterns (with generalized keywords) from the raw user logs of the Microsoft Encarta search engine (). Those query patterns can act as cache of the search engine, improving its performance. The cache of the generalized query patterns is more advantageous than the cache of the most frequent user queries since our patterns are generalized, covering more queries and future queries — even those not previously asked. Our method is unique since query patterns discovered reflect the actual dynamic usage and user feedbacks of the search engine, rather than the syntactic linkage structure of web pages (as Google does). Simulation shows that such generalized query patterns improve search engine's overall speed considerably. The generalized query patterns, when viewed with a graphical user interface, are also helpful to web editors, who can easily discover topics in which users are mostly interested.

Distributed applications monitoring at system and network level

Most distributed applications are based on architectural models that do not involve real-time knowledge of network status and of their network usage. Moreover the new “network aware” architectures are still under development and their design is not yet complete. We considered, as a use case, an application using ODBMS (Objectivity/DB) for the distributed analysis of experimental data. The dynamic usage of system and network resources at host and application levels has been measured in different client/server configurations, and on several LAN and WAN layouts. The aim was to study the application efficiency and behavior versus the network characteristics and conditions. The most interesting results of the LAN and WAN tests are described. System bottlenecks and limitations have been identified, and efficient working conditions in the different scenarios have been defined. The behavior observed when moving away from the optimal working conditions is also described.

Performance evaluation of fair packet discarding in network with multiple bottlenecks

Fair packet discarding (FPD) is a mechanism which provides incentives to users for participation in congestion control, such that ATM networks can operate in a more efficient manner. The authors study the performance of FPD in a general network with multiple bottlenecks. By simulations. They show that the interaction between FPD and ATM Forum's explicit-rate flow control enables the packet-level throughput of each connection converging to the max-min fair apportionment in a distributed manner. With the built-in policing capability of FPD, the need of dynamic usage parameter control for ABR service is also eliminated.

Video transport in ATM networks: a systems view

This paper presents a systems view of video transport issues in asynchronous transfer mode (ATM) networks. Since video is a critical component of future distributed multimedia applications, we consider technical approaches necessary to realize a flexible, robust, and efficient ATM framework for video delivery. The overall system-design problem is discussed for a general distributed multimedia computing scenario, and key video-related design issues are identified. This is followed by a more detailed discussion of selected ATM video topics, including: (1) variable bit-rate (VBR) statistical multiplexing and dynamic usage parameter control (VBR+), (2) ATM cell-loss concealment in MPEG decoders, and (3) new transport protocols (“MTP”) for video and multimedia. Supporting simulation or experimental results from ongoing research are given where available.

HYSIM: Hybrid Fault Simulation for Synchronous Sequential Circuits

The paper identifies the inefficiencies of the critical processes in concurrent fault simulation and proposes methods to remove such inefficiencies in a systematic manner. Also, proposed are dynamic memory usage reduction strategies for concurrent fault simulators. Through extensive step-by-step experimentation, we verified the effectiveness of the proposed methods for performance improvement and identified best memory management strategy for dynamic memory usage reduction. A simulator, HySim, based on the proposed methods is implemented and shown to outperform the existing fault simulators and achieve dramatic memory usage reduction. The HySim maintains fault lists which are subsets of that of a conventional concurrent fault simulator, which yields shorter fault list processing time and reduced dynamic memory usage. It also employs Release-and-Reconstruct method for fault list construction, where any fault list identified to be useless is released immediately. The experimental results show that Release-and-Reconstruct method is very effective in dynamic memory usage reduction.

Dotplot patterns: A literal look at pattern languages

This article describes the dotplot data visualization technique and its potential for contributing to the identification of design patterns. Pattern languages have been used in architectural design and urban planning to codify related rules-of-thumb for constructing vernacular buildings and towns. When applied to software design, pattern languages promote reuse while allowing novice designers to learn from the insights of experts. Dotplots have been used in biology to study similarity in genetic sequences. When applied to software, dotplots identify patterns that range in abstraction from the syntax of programming languages to the organizational uniformity of large, multicomponent systems. Dotplots are useful for design by successive abstraction—replacing duplicated code with macros, subroutines, or classes. Dotplots reveal a pervasive design pattern for simplifying algorithms by increasing the complexity of initialization. Dotplots also reveal patterns of wordiness in languages—one example Inspired a design pattern for a new programming language. In addition, dotplots of data associated with programs Identify dynamic usage patterns—one example identifies a design pattern used in the construction of a UNIX(tm) file system. © 1996 John Wiley & Sons, Inc.

Dotplot patterns: A literal look at pattern languages

This article describes the dotplot data visualization technique and its potential for contributing to the identification of design patterns. Pattern languages have been used in architectural design and urban planning to codify related rules-of-thumb for constructing vernacular buildings and towns. When applied to software design, pattern languages promote reuse while allowing novice designers to learn from the insights of experts. Dotplots have been used in biology to study similarity in genetic sequences. When applied to software, dotplots identify patterns that range in abstraction from the syntax of programming languages to the organizational uniformity of large, multicomponent systems. Dotplots are useful for design by successive abstraction—replacing duplicated code with macros, subroutines, or classes. Dotplots reveal a pervasive design pattern for simplifying algorithms by increasing the complexity of initialization. Dotplots also reveal patterns of wordiness in languages—one example Inspired a design pattern for a new programming language. In addition, dotplots of data associated with programs Identify dynamic usage patterns—one example identifies a design pattern used in the construction of a UNIX(tm) file system. © 1996 John Wiley & Sons, Inc.

Effective potentials and chaos in quantum systems.

The dynamic usage of the technique of effective potentials is motivated and established. The one-loop effective potential and the Gaussian effective potential are derived from Ehrenfrest's theorem by using adiabatic elimination. An application is made to the H\'enon-Heiles problem, and comparison is made with previous results; it is shown that quantum effects destroy chaos in two ways: (a) quantum fluctuations make the curvature more positive and (b) tunneling dominates the dynamics.

Relating static and dynamic machine code measurements

In an effort to relate static measurements of machine code instructions and addressing modes to their dynamic counterparts, both types of measurements were made on nine different machines using a large and varied suite of programs. Using classical regression analysis techniques, the relationship between static architecture measurements and dynamic architecture measurements was explored. The statistical analysis showed that many static and dynamic measurements are strongly correlated and that it is possible to use the more easily obtained static measurements to predict dynamic usage of instructions and addressing modes. With few exceptions, the predictions are accurate for most architectural features.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The file allocation problem under dynamic usage

The file allocation problem considers a file and a fully connected network having n nodes. The problem assumes that the overall file usage over a unit time period is known and it asks for the optimal set of network sites at which to locate copies of the file. This paper considers the same problem but it assumes that the behavior of the user access patterns changes over v planning periods in a manner, known in advance. A model is presented which shows that there are (2 n − 1) v possible file allocations. To assist the searching of this large solution space four theorems are presented which are subsequently utilized to analyze the problem and to solve an example case.

Effect of Milling on Properties of Hevea and Buna Rubbers

Abstract 1. The superior cut-growth resistance of Hevea tread stock is partly ascribed to its pronounced relaxation or lengthening when subjected to repeated severe cyclic extensions. Under such conditions the breaking elongation increases from 700 to 900%. GR-S under similar treatment fails to develop any lengthening. 2. As a consequence of this failure to lengthen under repeated severe strains, such as those antecedent to cut-growth failure, GR-S exhibits higher modulus, i.e., at 500 or 600 per cent elongation, or higher retractive forces than does Hevea. This also promotes cut growth. 3. In Hevea, progressive milling (at normal temperature) of tread stocks tends to develop a tensile maximum. At this point of optimum milling, d.c. resistivity reaches a minimum. Overmilling, characterized by a decrease in tensile, shows a sharp rise in log R. 4. With Perbunan, highest tensiles and elongations are realized only after several remillings, at which point modulus and Shore hardness have already shown marked decline. 5. With Buna-S (GR-S), tensile and elongation reach their maxima at about one remilling (at normal temperatures). Milling beyond this point is reflected in sharp degradation of elongation. Log R provides no indication of optimum conditions, since it is rising at this point. 6. In Butyl B, tensile and modulus reach a simultaneous maximum between two and three remillings. Log R in this region is declining and reflects retardation due to the softness of Butyl stocks. 7. Hot milling of GR-S shortens and reduces heat and flex properties. Cold refining lengthens GR-S and improves these properties, but does not protect against subsequent damage from heat. GR-S shortened by heat cannot be restored by subsequent cold refining. The benefits of cold refining apply also to the completely formulated tread. 8. Extreme development of the cold-refining technique produces the following results (based on treatment of complete tread mixing) : Modulus declines continuously to less than 50 per cent of control. Elongation increases continuously to 125 per cent of control. Tensile strength increases to 110 per cent at 20 passes and then remains steady. Hot-iron life (thermal shortening) improves continuously to 310 per cent at 80 passes. Cut-growth resistance improves progressively to 370 per cent of control at 160 passes, and is still rising. 9. The fact that such striking all-round quality takes place at about fifty cold refinings with rolls at 80° F (stock at about 120° F) suggests the importance, in the fabrication of GR-S tires and other products subject to dynamic usage, of (a) avoidance of elevated temperatures at all stages, and (b) further study of the remedial effects of strenuous mastication of refining of GR-S tread type, carbon-reinforced stocks under low-temperature conditions. 10. Attempts to improve GR-S should be oriented in two opposite senses: to decrease its hysteresis at low extensions (under 100 per cent) but to increase its hysteresis, or capacity to relax, at the higher extensions antecedent to cut growth.