Ramayya Krishnan
Carnegie Mellon University, Heinz School, Faculty Member
Abstract Revelation policies in an electronic marketplace differ in terms of the level of competitive information disseminated to participating sellers. Since sellers who repeatedly compete against one another learn based on the... more
Abstract Revelation policies in an electronic marketplace differ in terms of the level of competitive information disseminated to participating sellers. Since sellers who repeatedly compete against one another learn based on the information revealed and alter their future bidding behavior, revelation policies affect welfare parameters—consumer surplus, producer surplus, and social welfare—of the market.
Abstract: The rise of socially targeted marketing suggests that decisions made by consumers can be predicted not only from their personal tastes and characteristics, but also from the decisions of people who are close to them in their... more
Abstract: The rise of socially targeted marketing suggests that decisions made by consumers can be predicted not only from their personal tastes and characteristics, but also from the decisions of people who are close to them in their networks. One obstacle to consider is that there may be several different measures for" closeness" that are appropriate, either through different types of friendships, or different functions of distance on one kind of friendship, where only a subset of these networks may actually be relevant.
1. ABSTRACT Through our study we empirically test the role of peers on diffusion of niche music in an online social network. Over the last few years, online networks have been gaining popularity and allowing community members to share and... more
1. ABSTRACT Through our study we empirically test the role of peers on diffusion of niche music in an online social network. Over the last few years, online networks have been gaining popularity and allowing community members to share and exchange information. Traditionally this online diffusion of information was dependent on other mechanisms like viral marketing, recommender systems, and online word-ofmouth. But due to information overload the effectiveness of these mechanisms is reduced.
Abstract: Peer to peer networks will become an increasingly important distribution channel for consumer information goods and may play a role in the distribution of information within corporations. Our research analyzes optimal membership... more
Abstract: Peer to peer networks will become an increasingly important distribution channel for consumer information goods and may play a role in the distribution of information within corporations. Our research analyzes optimal membership rules for these networks in light of positive and negative externalities additional users impose on the network.
Abstract Person-to-Person lending (P2PL) is a new and exciting Internet application. Currently, there is limited understanding of the behavior of P2PL markets and their participants because of the uniqueness and youth of these markets. In... more
Abstract Person-to-Person lending (P2PL) is a new and exciting Internet application. Currently, there is limited understanding of the behavior of P2PL markets and their participants because of the uniqueness and youth of these markets. In this paper, we make the case that lenders' search for listings to bid on is an integral part of lender behavior, and analyses of P2PL that do not give explicit consideration to the nature of this search may very well draw inappropriate conclusions.
Abstract: Peer-to-Peer (P2P) networks have emerged as a significant social phenomenon for the distribution of information goods and may become an important alternative to traditional client-server network architectures for knowledge... more
Abstract: Peer-to-Peer (P2P) networks have emerged as a significant social phenomenon for the distribution of information goods and may become an important alternative to traditional client-server network architectures for knowledge sharing within enterprises.
Abstract One key aspect of better and more secure software is timely and reliable patching of vulnerabilities by software vendors. Recently, software vulnerability disclosure, which refers to the publication of vulnerability information... more
Abstract One key aspect of better and more secure software is timely and reliable patching of vulnerabilities by software vendors. Recently, software vulnerability disclosure, which refers to the publication of vulnerability information before a patch to fix the vulnerability has been issued by the software vendor, has generated intense interest and debate. In particular, there have been arguments made both in opposition to and in favor of alternatives such as full and instant disclosure and limited or no disclosure.
Abstract Geographically dispersed sellers in electronic reverse marketplaces such as those hosted by market-makers like Ariba are uncertain about the number of competitors they face in any given market session. We refer to this... more
Abstract Geographically dispersed sellers in electronic reverse marketplaces such as those hosted by market-makers like Ariba are uncertain about the number of competitors they face in any given market session. We refer to this uncertainty about the number of competitors as market-structure uncertainty. Over the course of several market sessions sellers learn about the competitive nature of the marketplace.
Abstract This study examines the learning curves of IS knowledge workers, using data from a computing call center. We find that (a) learning rate of the group in charge of requests associated with application-level knowledge is faster... more
Abstract This study examines the learning curves of IS knowledge workers, using data from a computing call center. We find that (a) learning rate of the group in charge of requests associated with application-level knowledge is faster than that of the group of technical level knowledge in terms of average resolution time,(b) variance of resolution times becomes smaller in only the generalist group and (c) knowledge transfers across IS problem types. Theoretical and practical implications are discussed.
• Implemented a collection of mathematical models and algorithms that can be used to help an assessor develop plans to evaluate the data quality of an existing AIS or to design the procedures required to ensure that an AIS meets specific... more
• Implemented a collection of mathematical models and algorithms that can be used to help an assessor develop plans to evaluate the data quality of an existing AIS or to design the procedures required to ensure that an AIS meets specific data quality goals. Our implementation is available on the World-Wide Web at http://www. heinz. cmu. edu/djk/ais. html
Abstract A primary tool that consumers have for comparative shopping is the shopbot, which is short for shopping robot. These shopbots automatically search a large number of vendors for price and availability. Typically a shopbot searches... more
Abstract A primary tool that consumers have for comparative shopping is the shopbot, which is short for shopping robot. These shopbots automatically search a large number of vendors for price and availability. Typically a shopbot searches a predefined set of vendors and reports all results, which can result in time-consuming searches that provide redundant or dominated alternatives. Our research demonstrates analytically how shopbot designs can be improved by developing a utility model of consumer purchasing behavior.
The increasing demand for information, coupled with the increasing capability of computer systems, has compelled information providers to reassess their procedures for preventing disclosure of con dential information. This paper considers... more
The increasing demand for information, coupled with the increasing capability of computer systems, has compelled information providers to reassess their procedures for preventing disclosure of con dential information. This paper considers the problem of protecting an unpublished, sensitive table by suppressing cells in related, published tables. A conventional integer programming technique for two-dimensional tables is extended to nd an optimal suppression set for the public tables.
Abstract The tomato-tomahto problem (known as the synonymy problem in the database literature) arises in the context of model management when different names are used in different models for what should be identical variables, and these... more
Abstract The tomato-tomahto problem (known as the synonymy problem in the database literature) arises in the context of model management when different names are used in different models for what should be identical variables, and these different models are to be integrated or combined into a larger model. When this problem occurs, it is said that the unique names assumption has been violated. We propose a method by which violations of the unique names assumption can be automatically detected.
Abstract The World Wide Web has been highly successful as a tool for the distributed publishing and sharing of online documents among large dispersed groups. This raises the question whether the distributed authoring and execution of... more
Abstract The World Wide Web has been highly successful as a tool for the distributed publishing and sharing of online documents among large dispersed groups. This raises the question whether the distributed authoring and execution of software modules can be supported in a similar manner. We study this problem by first developing the requirements of a group of developers and users of statistical software at a German national research laboratory.
The rise of business-to-consumer electronic commerce represents one of the greatest economic experiments in history. In its initial conception, anyone could start a business-to-consumer firm. By shipping goods directly from wholesalers,... more
The rise of business-to-consumer electronic commerce represents one of the greatest economic experiments in history. In its initial conception, anyone could start a business-to-consumer firm. By shipping goods directly from wholesalers, firms would run extremely efficient operations. They would spend only on the website and earn money from sales, possibly from advertising, and from interest earned because goods were sold before suppliers had to be paid.
Abstract: Improving the information retrieval (IR) performance of P2P networks is an important and challenging problem. Recently, the computer science literature has tried to address this problem by improving the efficiency of search... more
Abstract: Improving the information retrieval (IR) performance of P2P networks is an important and challenging problem. Recently, the computer science literature has tried to address this problem by improving the efficiency of search algorithms. However, little attention has been paid to improving performance through the design of incentives for encouraging users to share content and, mechanisms for enabling peers to form communities based on shared interests.
Abstract: In this paper we analyze a software diversification-based strategy to achieve information security. The notion of using diversity to limit correlated risks is a widely accepted strategy in many fields. Various risk management... more
Abstract: In this paper we analyze a software diversification-based strategy to achieve information security. The notion of using diversity to limit correlated risks is a widely accepted strategy in many fields. Various risk management approaches strive to minimize the variance of losses faced by individuals by either risk pooling, as in insurance, or diversification, as in portfolio management. However, these approaches are advantageous only for risk-averse agents as the expected loss remains unchanged.
For the individual or organization wishing to employ a scientific approach in solving decision problems, there is a plethora of relevant concepts, methods, models, and software. Yet, relative to their potential or to peer software such as... more
For the individual or organization wishing to employ a scientific approach in solving decision problems, there is a plethora of relevant concepts, methods, models, and software. Yet, relative to their potential or to peer software such as database technologies, decision technologies are little used in real-world decision making. We argue that at least some of the problems that restrict the use of decision technologies are rooted in the use of conventional market mechanisms to distribute them.
Abstract DecisionNet is a distributed, Web-based electronic market for decision technologies such as data, models, solution algorithms, and modeling environments. Consumer-provider interactions are facilitated by model management software... more
Abstract DecisionNet is a distributed, Web-based electronic market for decision technologies such as data, models, solution algorithms, and modeling environments. Consumer-provider interactions are facilitated by model management software agents provided by DecisionNet. To illustrate different approaches for designing this agent functionality, we present two agents that embody different designs for mediating consumer and provider interaction with the AMPL and GAMS modeling environments.
Abstract Regional healthcare initiatives seek to improve the quality of healthcare by collecting, analyzing, and disseminating information about chronic diseases such as diabetes. The data required to support such initiatives comes from... more
Abstract Regional healthcare initiatives seek to improve the quality of healthcare by collecting, analyzing, and disseminating information about chronic diseases such as diabetes. The data required to support such initiatives comes from several organizations such as insurers, physicians, hospitals, pharmacies and labs each of which gather and maintain data for the purpose of healthcare delivery.
Abstract As databases grow more prevalent and comprehensive, database administrators seek to limit disclosure of confidential information while still providing access to data. Practical databases accommodate users with heterogeneous needs... more
Abstract As databases grow more prevalent and comprehensive, database administrators seek to limit disclosure of confidential information while still providing access to data. Practical databases accommodate users with heterogeneous needs for access. Each class of data user is accorded access to only certain views. Other views are considered confidential, and hence to be protected.
Abstract We give quasipolynomial-time approximation algorithms for designing networks with a minimum degree. Using our methods, one can design networks whose connectivity is specified by “proper” functions, a class of 0–1 functions... more
Abstract We give quasipolynomial-time approximation algorithms for designing networks with a minimum degree. Using our methods, one can design networks whose connectivity is specified by “proper” functions, a class of 0–1 functions indicating the number of edges crossing each cut.
Abstract The authors examine the relevance of reasoning with assumptions in two processes that are desired to be supported in model management systems, namely model formulation and model version management. They submit, and illustrate... more
Abstract The authors examine the relevance of reasoning with assumptions in two processes that are desired to be supported in model management systems, namely model formulation and model version management. They submit, and illustrate with an example, that the ability to represent and reason with assumptions in modeling languages could lead to significant improvement in the functionality of model management systems.
ABSTRACT Peer-to-peer networks have emerged as a popular alternative to traditional client-server architectures for the distribution of information goods. Recent academic studies have observed high levels of free-riding in various... more
ABSTRACT Peer-to-peer networks have emerged as a popular alternative to traditional client-server architectures for the distribution of information goods. Recent academic studies have observed high levels of free-riding in various peer-to-peer networks, leading some to predict the imminent collapse of communities hosted on these networks.
ABSTRACT The last few years have seen a tremendous growth in the number of applications being developed on the world wide web (WWW). Models for analyzing and designing these applications are only just beginning to emerge. In this work, we... more
ABSTRACT The last few years have seen a tremendous growth in the number of applications being developed on the world wide web (WWW). Models for analyzing and designing these applications are only just beginning to emerge. In this work, we propose a 3-dimensional classification space for WWW applications. Next, we propose metrics for WWW applications along one of the dimensions of this space.
Abstract Beginning with transparent and ubiquitous access to multimedia documents marked up in HTML, the Web has evolved (and continues to evolve) dramatically to incorporate a range of network computing technologies. These include... more
Abstract Beginning with transparent and ubiquitous access to multimedia documents marked up in HTML, the Web has evolved (and continues to evolve) dramatically to incorporate a range of network computing technologies. These include network-centric languages such as Java, software component architectures such as ActiveX, and distributed object technologies such as CORBA.
Abstract This paper describes IBIZA, a workbench for designing electronic markets for information products. IBIZA is a testbed for performing computational experiments about market-based approaches (eg, auctions) to support negotiations... more
Abstract This paper describes IBIZA, a workbench for designing electronic markets for information products. IBIZA is a testbed for performing computational experiments about market-based approaches (eg, auctions) to support negotiations between buyers and sellers. We outline the key technical and economic issues encountered in the design of IBIZA. We use examples from our work on designing a software agent-based electronic market for automated model development illustratively.
Abstract This article investigates the economic consequences of data errors in the information flows associated with business processes. We develop a process modeling-based methodology for managing the risks associated with such data... more
Abstract This article investigates the economic consequences of data errors in the information flows associated with business processes. We develop a process modeling-based methodology for managing the risks associated with such data errors. Our method focuses on the topological structure of a process and takes into account its effect on error propagation and risk mitigation using both expected loss and conditional value-at-risk risk measures.
Abstract Regional healthcare initiatives seek to improve the quality of healthcare by collecting, analyzing, and disseminating information about chronic diseases such as diabetes. The data required to support such initiatives comes from... more
Abstract Regional healthcare initiatives seek to improve the quality of healthcare by collecting, analyzing, and disseminating information about chronic diseases such as diabetes. The data required to support such initiatives comes from several organizations such as insurers, physicians, hospitals, pharmacies and labs each of which gather and maintain data for the purpose of healthcare delivery.
We are going to talk about parallel computing and high-end systems. Parallel processing does not need any introduction, nor definition. Despite this we offer one; to invoke concurrent computations for portions of a single application. Key... more
We are going to talk about parallel computing and high-end systems. Parallel processing does not need any introduction, nor definition. Despite this we offer one; to invoke concurrent computations for portions of a single application. Key are the words “concurrent” and “single application.” There are many important applications that are so blatantly parallel that they are not of concern or interest to us here. Also not of interest here is the notion of the concurrent throughput of many individual jobs.
Abstract The benefits of a security mechanism should be weighed against its cost to maximize system utility. However, traditional hard security techniques (cryptography) consider only the worst-case situation thus complicating security... more
Abstract The benefits of a security mechanism should be weighed against its cost to maximize system utility. However, traditional hard security techniques (cryptography) consider only the worst-case situation thus complicating security mechanism for electronic commercial transaction.
Blogs have been popular on the Internet for a number of years and are becoming increasingly popular within organizations as well. The analysis of blog posts is a useful way to understand the nature of expertise within a firm. In this... more
Blogs have been popular on the Internet for a number of years and are becoming increasingly popular within organizations as well. The analysis of blog posts is a useful way to understand the nature of expertise within a firm. In this paper we are interested in understanding the topics of conversations that evolve through blog posts and replies. While keywords within blog posts can be used to characterize the topic being discussed, their timestamps permit one to monitor how the intensity of the topic has changed over time.
The widespread growth in the organizational use of information systems underscores the practical importance of assessing their reliability. This has become more important as information systems are networked and become increasingly... more
The widespread growth in the organizational use of information systems underscores the practical importance of assessing their reliability. This has become more important as information systems are networked and become increasingly interdependent on one another, raising the possibility that errors introduced in any one system can propagate to others [6].
Abstract Peer-to-peer (P2P) file sharing networks are an important medium for the distribution of information goods. However, there is little empirical research into the optimal design of these networks under real-world conditions. Early... more
Abstract Peer-to-peer (P2P) file sharing networks are an important medium for the distribution of information goods. However, there is little empirical research into the optimal design of these networks under real-world conditions. Early speculation about the behavior of P2P networks has focused on the role that positive network externalities play in improving performance as the network grows.
Abstract The rise of socially targeted marketing suggests that decisions made by consumers can be predicted not only from their personal tastes and characteristics, but also from the decisions of people who are close to them in their... more
Abstract The rise of socially targeted marketing suggests that decisions made by consumers can be predicted not only from their personal tastes and characteristics, but also from the decisions of people who are close to them in their networks. One obstacle to consider is that there may be several different measures for “closeness” that are appropriate, either through different types of friendships or different functions of distance on one kind of friendship.
Abstract The digital economy is creating abundant opportunities for operations research (OR) applications. Several factions of the profession are beginning to respond aggressively, leading to notable successes in such areas as financial... more
Abstract The digital economy is creating abundant opportunities for operations research (OR) applications. Several factions of the profession are beginning to respond aggressively, leading to notable successes in such areas as financial services, electronic markets, network infrastructure, packaged OR-software tools, supply-chain management, and travel-related services.
Negotiation has traditionally been an important element in all types of commerce. As electronic commerce systems become generally available on the Internet, there is a need to support negotiation in the context of deal making. However, as... more
Negotiation has traditionally been an important element in all types of commerce. As electronic commerce systems become generally available on the Internet, there is a need to support negotiation in the context of deal making. However, as in the physical world, the type of negotiation mechanism required is context dependent. In particular, we distinguish between the support required in the context of single deal and support required in coordinating negotiations across multiple deals.
Abstract Competitive information revealed in a marketplace will have significant impact on the learning ability of the participating sellers across market sessions and therefore, on performance of the marketplace.
Abstract Peer-to-peer networking is gaining popularity as a architecture for sharing information goods and other computing resources. However, these networks suffer from a high level of free-riding, whereby some users consume network... more
Abstract Peer-to-peer networking is gaining popularity as a architecture for sharing information goods and other computing resources. However, these networks suffer from a high level of free-riding, whereby some users consume network resources without providing any network resources. The high levels of free-riding observed by several recent studies have led some to suggest the imminent collapse of these communities as a viable information sharing mechanism.
Abstract: Shopbots are software agents that automatically query a large number of vendors for price and availability of products. They are the primary tools for comparison-shopping on the Internet. Despite their apparent usefulness,... more
Abstract: Shopbots are software agents that automatically query a large number of vendors for price and availability of products. They are the primary tools for comparison-shopping on the Internet. Despite their apparent usefulness, shopbots impose considerable costs on their users because of the manner in which they make their operational decisions. Specifically, search tends to be slow resulting in high wait times for users.
ABSTRACT Using data collected between August 1999 and January 2000 covering 399 books, including New York Times bestsellers, computer bestsellers, and random books, we examine pricing by thirtytwo online bookstores. One common prediction... more
ABSTRACT Using data collected between August 1999 and January 2000 covering 399 books, including New York Times bestsellers, computer bestsellers, and random books, we examine pricing by thirtytwo online bookstores. One common prediction is that the reduction in search costs on the Internet relative to the physical channel would cause both price and price dispersion to fall. Over the sample period, we find no change in either price or price dispersion.
ABSTRACT Peer-to-peer networks have emerged as a popular alternative to traditional client-server architectures for the distribution of information goods. Recent academic studies have observed high levels of free-riding in various... more
ABSTRACT Peer-to-peer networks have emerged as a popular alternative to traditional client-server architectures for the distribution of information goods. Recent academic studies have observed high levels of free-riding in various peer-to-peer networks, leading some to predict the imminent collapse of communities hosted on these networks.
Abstract This begins a two-part commentary on management science and e-business, the theme of this two-part special issue. After explaining the topical clusters that give organization to both parts, we pose two key questions concerning... more
Abstract This begins a two-part commentary on management science and e-business, the theme of this two-part special issue. After explaining the topical clusters that give organization to both parts, we pose two key questions concerning the impact of the emerging digital economy on management science research: What fundamentally new research questions arise, and what kind of research enables progress on them.
We present a model to investigate the competitive implications of electronic secondary markets that promote concurrent selling of new and used goods on a supply chain. In secondary markets where suppliers cannot directly utilize used... more
We present a model to investigate the competitive implications of electronic secondary markets that promote concurrent selling of new and used goods on a supply chain. In secondary markets where suppliers cannot directly utilize used goods for practicing intertemporal price discrimination and where transaction costs of resales are negligible, the threat of cannibalization of new goods by used goods becomes significant.
Abstract Vulnerability disclosure is an area of public policy that has been subject to considerable debate, particularly between proponents of full and instant disclosure, and those of limited or no disclosure. This paper is an attempt to... more
Abstract Vulnerability disclosure is an area of public policy that has been subject to considerable debate, particularly between proponents of full and instant disclosure, and those of limited or no disclosure. This paper is an attempt to empirically test the impact of vulnerability information disclosure and availability of patches on attackers' tendency to exploit vulnerabilities on one hand and on the vendors' tendency to release patches on the other.
ABSTRACT Using data collected between August 1999 and January 2000, we examine firm-level pricing strategies for 32 online bookstores. The data cover more than 300 books, including New York Times bestsellers, computer bestsellers, and... more
ABSTRACT Using data collected between August 1999 and January 2000, we examine firm-level pricing strategies for 32 online bookstores. The data cover more than 300 books, including New York Times bestsellers, computer bestsellers, and random books. Over the period, standard deviation of price fell slightly, and prices for the different types of books were substantially above cost and flat or increasing. Thus predicted price convergence has not yet occurred.
Two con£ icting predictions have emerged regarding the e¡ ect of lowcost information on price. The¢ rst states that all Internet retailers will charge the same low price for mass produced goods. The second states that Internet retailers... more
Two con£ icting predictions have emerged regarding the e¡ ect of lowcost information on price. The¢ rst states that all Internet retailers will charge the same low price for mass produced goods. The second states that Internet retailers will di¡ erentiate to avoid intense price competition. Using data collected in April 1999 on the prices of 107 books in thirteen online and two physical bookstores, we¢ nd similar average prices online and in physical stores and substantial price dispersion online.
Even in the age of electronic dissemination of statistical data, tables are central data products of statistical agencies. For prominent examples, see the American FactFinder (http://factfinder. census. gov/servlet/BasicFactsServlet) from... more
Even in the age of electronic dissemination of statistical data, tables are central data products of statistical agencies. For prominent examples, see the American FactFinder (http://factfinder. census. gov/servlet/BasicFactsServlet) from the US Bureau of Census, the Office of National Statistics (http://www. statistics. gov. uk/) in the UK, and Statistics Netherlands (http://www. cbs. nl/en/figures/keyfigures/index. htm).
Abstract This paper reports the results of a study of Web usage of 139 users over a 8 month period of time. It uses a longitudinal Web log analysis of the URLs accessed during 33916 user-days of Web usage. It aims to detect changes in Web... more
Abstract This paper reports the results of a study of Web usage of 139 users over a 8 month period of time. It uses a longitudinal Web log analysis of the URLs accessed during 33916 user-days of Web usage. It aims to detect changes in Web usage associated with increased experience of using the Web. Specifically, it answers the question whether or not users shift from undirected browsing in the Web to directed access of Web sites as they gain expertise in using the Web.