Papers by Shenoda Guirguis
… , 2009. ICDE'09. …, Jan 1, 2009
In highly interactive dynamic web database systems, user satisfaction determines their success. I... more In highly interactive dynamic web database systems, user satisfaction determines their success. In such systems, userrequested web pages are dynamically created by executing a number of database queries or web transactions. In this paper, we model the interrelated transactions generating a web page as workflows and quantify the user satisfaction by associating dynamic web pages with soft-deadlines. Further, we model the importance of transactions in generating a page by associating different weights to transactions. Using this framework, system success is measured in terms of minimizing the deviation from the deadline (i.e., tardiness) and also minimizing the weighted such deviation (i.e., weighted tardiness).
…, Jan 1, 2008
User satisfaction determines the success of webdatabase applications. User satisfaction can be ex... more User satisfaction determines the success of webdatabase applications. User satisfaction can be expressed in terms of expected response time or expected delay. Given the bursty and unpredictable behavior of web user populations, we model user requests as transactions with softdeadlines. For such a model of user requests with softdeadlines, the hit ratio is not the most expressive metric. Instead, the average tardiness is a better measure in such cases. In this paper; we propose and evaluate an adaptive self-managing algorithm called ASETS, which optimizes for the average tardiness. ASETS prioritize resources as needed in order to keep users satisfied under varying workloads. Our performance evaluation shows ASETS to outperform both EDF and SRPT which are known to be optimal for the under and over utilization system conditions respectively.
Multimedia Tools and …, Jan 1, 2010
Multimedia applications nowadays are becoming prevalent. In the past the relational database mode... more Multimedia applications nowadays are becoming prevalent. In the past the relational database model was generalized to the multimedia database model. More recently the relational database model was generalized to the data streams model, as the technology advanced and data became bulky and unbounded in size due to the utilization of sensor networks. In this paper we take one more step of generalization by providing a multimedia data streams model. The objective is to furnish a formal framework to design multimedia data streams (MMDS) schema for efficient content based information retrieval. We also extend the functional dependency theory and the normalization framework to handle multimedia data streams. Finally we present algorithmic methods of generating continuous multimedia queries along with examples for illustration. 2. Motivating Examples As motivating examples we present the following three applications-a security system, a health application, and an aircraft database system. Motivating example 1-Security System: A security system usually has video cameras installed in hidden places in some secured building or store. Typically a guard or two keep rotating between the captured videos and they interfere when something suspicious or a threat occurs. However, this security system has two major problems: first, inevitable human error, and second, if a WANTED person shows up, it is less likely that the security guard can pay attention, and hence interfere before the crises (as opposed to after the crises). However, if we have a multimedia data stream management system that receives the stream of videos (or stream of frames) and has a relation (i.e. a table) with images of all WANTED criminals, and another relation with images of all weapons. Then one can preregister couple of useful continuous queries to automate the task of the guards, and help them do their job and avoid human errors. Such CQs may include: 1) Tell me whenever you see an object similar to any weapon. 2) Tell me whenever you see a WANTED person. 3) Tell me whenever an object (or more) in several frames within the last 30 seconds moves in a very "violent" manner. 4) If any of the above, start recording the video on a "Threat" clip for future reference. Thus, if the guard missed anything, or had to leave his place for whatever reason, the system can help him. Moreover, new things that he was not able to do, such as identifying WANTED criminals, is now achievable. Motivating example 2-Health-care System: One of the major data streams applications is the health monitoring systems, where the patient"s heart rate, body temperature, etc. are continuously monitored, and a CQ to report when these values go beyond the normal values. Imagine the case for some diseases when an X-Ray photo needs to be inspected to show progress or to identify anomalies. This is a multimedia data stream that can be fed to a multimedia data stream management system with the appropriate continuous queries. Motivating example 3-Airport Security: Assume we have a multimedia database with multimedia objects being still images of object types. And then we have a multimedia stream of video frames taken by some airport"s security
… Workshops 2006. Sixth …, Jan 1, 2006
This paper proposes a novel research dimension in the field of data mining, which is mining the f... more This paper proposes a novel research dimension in the field of data mining, which is mining the future data before its arrival, or in other words: predicting association rules ahead before the arrival of the data. To achieve that, we need only predict the itemsets' support, upon which association rules could be easily produced. A time series analysis approach (MFTP) is proposed to perform itemsets' support prediction task. The proposed technique outperforms other prediction techniques for short history. The conducted performance study showed good prediction accuracy and response time. This, we provide a new tool to provide more information in the decision support field.
Amazon, Google, and IBM now sell cloud computing services. We consider the setting of a for-profi... more Amazon, Google, and IBM now sell cloud computing services. We consider the setting of a for-profit business selling data stream monitoring/management services and we investigate auction-based mechanisms for admission control of continuous queries. When submitting a query, each user also submits a bid of how much she is willing to pay for that query to run. The admission control auction mechanism then determines which queries to admit, and how much to charge each user in a way that maximizes system revenue while being strategyproof and sybil immune, incentivizing users to use the system honestly. Specifically, we require that each user maximizes her payoff by bidding her true value of having her query run. We design several payment mechanisms and experimentally evaluate them. We describe the provable game theoretic characteristics of each mechanism alongside its performance with respect to maximizing profit and total user payoff.
… of the 13th International Conference on …, Jan 1, 2010
Data privacy laws have appeared recently, such as the HIPAA laws for protecting medical records, ... more Data privacy laws have appeared recently, such as the HIPAA laws for protecting medical records, and the PCI guidelines for protecting Credit Card information. Data privacy can be defined as maintaining the privacy of Personal Identifiable Information (PII) from unauthorized accessing. . PII includes any piece of data that can be used alone, or in conjunction with additional information, to uniquely identify an individual. Examples of such information include national identification numbers, credit card numbers, as well as financial and medical records. Access control methods and data encryption provide a level of data protection from unauthorized access, however, it is not enough; it does not prohibit identity thefts. It was reported that 70% of the data privacy breaches are internal breaches that involve an employee from the enterprise who has access to some training or testing database replica, which contains all the PII. In addition to access control, we need techniques to obfuscate (i.e., mask or dim) the datasets used for training, testing and analysis purposes. A good data obfuscation technique would, among other features, preserve the data usability while protecting its privacy. This challenge is further complicated when real time requirements are added. In this paper we present BronzeGate: Obfuscated GoldenGate, the GoldenGate's real-time solution for transactional data privacy while maintaining data usability. BronzeGate utilizes different obfuscation functions for different data types to securely obfuscate the data, on real-time, while maintaining its statistical characteristics.
Abstract: Multimedia applications nowadays are becoming the standard, for they utilize the enormo... more Abstract: Multimedia applications nowadays are becoming the standard, for they utilize the enormous human brain computational power. In the past, the Relational Database Model was generalized to the Multimedia Databases Model. Orthogonally, the Relational ...
Uploads
Papers by Shenoda Guirguis