Methods and apparatuses for targeting the delivery of advertisements over a network such as the Internet are disclosed. Statistics are compiled on individual users and networks and the use of the advertisements is tracked to permit targeting of the advertisements of individual users. In response to requests from affiliated sites, an advertising server transmits to people accessing the page of a site an appropriate one of the advertisement based upon profiling of users and networks.

Method of delivery, targeting, and measuring advertising over networks

Web sites provide the key interface for consumer use of the Internet. This research reports on a series of three studies that developand validate Web site usability, design and performance metrics, including download delay, navigability, site content, interactivity, and responsiveness. The performance metric that was developed includes the subconstructs user satisfaction, the likelihood of return, and the frequency of use.Data was collected in 1997, 1999, and 2000 from corporate Web sites via three methods, namely, a jury, third-party ratings, and a software agent. Significant associations between Web site design elements and Web site performance indicate that the constructs demonstrate good nomological validity. Together, the three studies provide a set of measures with acceptable validity and reliability. The findings also suggest lack of significant common methods biases across the jury-collected data, third-party data, and agent-collected data.Results suggest that Web site success is a first-order construct. Moreover, Web site success is significantly associated with Web site download delay (speed of access and display rate within the Web site), navigation (organization, arrangement, layout, and sequencing), content (amount and variety of product information), interactivity (customization and interactivity), and responsiveness (feedback options and FAQs).

https://www.jstor.org/stable/pdfplus/23011053.pdf

Web Site Usability, Design, and Performance Metrics

Multithreaded programming is difficult and error prone. It is easy to make a mistake in synchronization that produces a data race, yet it can be extremely hard to locate this mistake during debugging. This article describes a new tool, called Eraser, for dynamically detecting data races in lock-based multithreaded programs. Eraser uses binary rewriting techniques to monitor every shared-monory reference and verify that consistent locking behavior is observed. We present several case studies, including undergraduate coursework and a multithreaded Web search engine, that demonstrate the effectiveness of this approach.

/pdf/eraser-a-dynamic-data-race-detector-for-multithreaded-1jusm8qlv8.pdf

Eraser: a dynamic data race detector for multithreaded programs

Multi-threaded programming is difficult and error prone. It is easy to make a mistake in synchronization that produces a data race, yet it can be extremely hard to locate this mistake during debugging. This paper describes a new tool, called Eraser, for dynamically detecting data races in lock-based multi-threaded programs. Eraser uses binary rewriting techniques to monitor every shared memory reference and verify that consistent locking behavior is observed. We present several case studies, including undergraduate coursework and a multi-threaded Web search engine, that demonstrate the effectiveness of this approach.

Eraser: a dynamic data race detector for multi-threaded programs

One approach to model checking software is based on the abstract-check-refine paradigm: build an abstract model, then check the desired property, and if the check fails, refine the model and start over. We introduce the concept of lazy abstraction to integrate and optimize the three phases of the abstract-check-refine loop. Lazy abstraction continuously builds and refines a single abstract model on demand, driven by the model checker, so that different parts of the model may exhibit different degrees of precision, namely just enough to verify the desired property. We present an algorithm for model checking safety properties using lazy abstraction and describe an implementation of the algorithm applied to C programs. We also provide sufficient conditions for the termination of the method.

Lazy abstraction

~lw advantage of , capability of rallel machines, application programs must contain sufficient parallelism, and this parallelism must be effectively scheduled on multiple processors. Loops without dependences among their iterations are a rich source of parallelism in scientific code. Restructuring compilers for sequential programs have been particularly successful in determining when loop iterations are independent and can be executed in parallel. Because of the prevalence of parallel loops, optimal parallel-loop scheduling has received considerable attention in both academic and industrial communities. The fundamental trade-off in scheduling parallel-loop iterations is that of maintaining balanced processor workloads vs. minimizing scheduling overhead. Consider, for example, a loop with N iterations that contain an IF statement. Depending on whether the body of the IF statement is executed, an iteration has LONG or SHORT execution time. If we naively schedule the iterations on P processors in chunks of N/P iterations, a strategy called static chunking (SC), a chunk of one processor may consist of iterations that are all LONG, while a chunk of another processor may consist of iterations that are all SHORT. Hence, different processors may finish at widely different times. Since the loop finishing time is equal to the latest finishing time of any of the processors executing the loop, the overall finishing time may be greater than optimal with SC. Alternatively, if we (also naively) schedule the iterations one at a time, a strategy called self-scheduling (SS), then there will be N scheduling operations. With SS, a processor obtains a new iteration whenever it becomes idle, so the processors finish at nearly the same time and the workload is balanced. Because of the scheduling overhead , however, the overall finishing time may be greater than optimal. The characteristics of the iterations determine which scheme performs better. For instance, variable-length, coarse-grained iterations favor SS, while constant-length, fine-grained iterations favor SC. Even when iterations do not contain conditional statements, their running times are likely to be variable because of interference from their environment (other iterations, the operating system, and other programs). The scheduling schemes just discussed are extremes; between the two lie schemes that attempt to minimize the cumulative contribution of uneven processor finishing times and of scheduling overhead. Such schemes schedule iterations in chunks of sizes greater than one but less than N/P, where size is the number of iterations in the chunk. Both fixed-size and variable-size chunk-ing schemes have been proposed. In …

Factoring: a method for scheduling parallel loops

A server system on a network such as the World Wide Web aggregates and stores information about the content of Web pages served by a server on a network. A server process receives one or more requests for Web pages from requesters connected to the network. Upon receiving the request, the server produces a requested Web page and serves the Web page to the requester. The Web pages have with one or more content elements in addition to one or more metadata entries. The metadata entries are associated with the content elements of the respective Web page produced. The system also creates and maintains a log having a plurality of records. Each record has requester fields and metadata fields. A logger process stores the metadata entries contained in each of the Web pages in one or more of the metadata fields, and stores a requester identification, associated with the requester, in the requester field of the record associated with the respective Web page.

System and method for collecting and analyzing information about content requested in a network (World Wide Web) environment

ThE paper presents an efficient on-the-fly method for detecting access anomalies in programs that contain critical section coordinw tion. For a large class of programs, a single execution instance is sufficient to determine theexistence of an acceeaanomaly for a given input when the proposed method is used. In contrast, for the same class of programs, previous on-the-fly methods for handling critical sections can fail to detect anomalies for a given input, and can require N! execution instances to find an anomaly, where N is the degree of parallelism. An algorithm for statically determining which programs are in this class is described.

Detecting access anomalies in programs with critical sections

One of the major disadvantages of parallel programming with shared memory is the nondeterministic behavior caused by uncoordinated access to shared variables, known as access anomalies. Monitoring program execution to detect access anomalies is a promising and relatively unexplored approach to this problem. We present a new algorithm, referred to as task recycling, for detecting anomalies, and compare it to an existing algorithm. Empirical results indicate several significant conclusions: (i) While space requirements are bounded by O(T × V), where T is the maximum number of threads that may potentially execute in parallel and V is the number of variable monitored, for typical programs space requirements are on average O(V). (ii) Task recycling is more efficient in terms of space requirements and often in performance. (iii) The general approach of monitoring to detect access anomalies is practical.

An empirical comparison of monitoring algorithms for access anomaly detection

Clickstreams are visitors' paths through a Web site. Analysis of clickstreams shows how a Web site is navigated and used by its visitors. Clickstream data of online stores contains information useful for understanding the effectiveness of marketing and merchandising efforts, such as how customers find the store, what products they see, and what products they purchase. In this paper, we present an interactive visualization system that provides users with greater abilities to interpret and explore clickstream data of online stores. This system visualizes the effectiveness of Web merchandising from two different points of view by using two different visualization techniques: visualization of sessions by using parallel coordinates and visualization of product performance by using starfield graphs. Furthermore, this system provides facilities for zooming, filtering, color-coding, dynamic querying and data sampling. It also provides summary information along with visualizations, and by maintaining a connection between visualizations and the source database, it dynamically updates the summary information. To demonstrate how the presented visualization system provides capabilities for examining online store clickstreams, we present a series of parallel coordinates and starfield visualizations that display clickstream data from an operating online retail store. A framework for understanding Web merchandising is briefly explained. A set of metrics referred to as i>micro-conversion rates, which are defined for Web merchandising analysis in our previous work (Lee et al., Electronic Markets, 2000), is also explained and used for the visualizations of online store effectiveness.

Edith Schonberg

Papers

Factoring: a method for scheduling parallel loops

System and method for collecting and analyzing information about content requested in a network (World Wide Web) environment

Detecting access anomalies in programs with critical sections

An empirical comparison of monitoring algorithms for access anomaly detection

Visualization and Analysis of Clickstream Data of Online Stores for Understanding Web Merchandising