Research directions in session-based and sequential recommendation

User Modeling and User-Adapted Interaction -     

Reusing software: issues and research directions

Software productivity has been steadily increasing over the past 30 years, but not enough to close the gap between the demands placed on the software industry and what the state of the practice can deliver; nothing short of an order of magnitude increase in productivity will extricate the software industry from its perennial crisis. Several decades of intensive research in software engineering and artificial intelligence left few alternatives but software reuse as the (only) realistic approach to bring about the gains of productivity and quality that the software industry needs. In this paper, we discuss the implications of reuse on the production, with an emphasis on the technical challenges. Software reuse involves building software that is reusable by design and building with reusable software. Software reuse includes reusing both the products of previous software projects and the processes deployed to produce them, leading to a wide spectrum of reuse approaches, from the building blocks (reusing products) approach, on one hand, to the generative or reusable processor (reusing processes), on the other. We discuss the implication of such approaches on the organization, control, and method of software development and discuss proposed models for their economic analysis. Software reuse benefits from methodologies and tools to: (1) build more readily reusable software and (2) locate, evaluate, and tailor reusable software, the last being critical for the building blocks approach. Both sets of issues are discussed in this paper, with a focus on application generators and OO development for the first and a thorough discussion of retrieval techniques for software components, component composition (or bottom-up design), and transformational systems for the second. We conclude by highlighting areas that, in our opinion, are worthy of further investigation     

Object-oriented databases: definition and research directions

An object-oriented database is defined and justified on the basis of a small set of central object-oriented concepts. A number of common misconceptions about object-oriented databases are discussed. The results of relevant recent research in object-oriented databases are outlined. Directions for future research in object-oriented databases are provided     

协同过滤推荐研究综述

推荐技术是目前在很多领域中广泛使用的技术之一.而协同过滤推荐算法是应用在推荐技术中很成功的算法.主要介绍了协同过滤推荐技术,总结了当前推荐算法的传统方法、改进算法以及性能评测方法.同时,分析了协同过滤推荐算法中的问题以及相应的解决办法.最后阐述了协同过滤推荐系统中仍需解决的问题和未来可能的发展方向.     

3D geo-database research: Retrospective and future directions

3D geo-database research is a promising field to support challenging applications such as 3D urban planning, environmental monitoring, infrastructure management, and early warning or disaster management and response. In these fields, interdisciplinary research in GIScience and related fields is needed to support the modelling, analysis, management, and integration of large geo-referenced data sets, which describe human activities and geophysical phenomena. Geo-databases may serve as platforms to integrate 2D maps, 3D geo-scientific models, and other geo-referenced data. However, current geo-databases do not provide sufficient 3D data modelling and data handling techniques. New 3D geo-databases are needed to handle surface and volume models. This article first presents a 25-year retrospective of geo-database research. Data modelling, standards, and indexing of geo-data are discussed in detail. New directions for the development of 3D geo-databases to open new fields for interdisciplinary research are addressed. Two scenarios in the fields of early warning and emergency response demonstrate the combined management of human and geophysical phenomena. The article concludes with a critical outlook on open research problems.     

The cyber threat landscape: Challenges and future research directions

Cyber threats are becoming more sophisticated with the blending of once distinct types of attack into more damaging forms. Increased variety and volume of attacks is inevitable given the desire of financially and criminally-motivated actors to obtain personal and confidential information, as highlighted in this paper. We describe how the Routine Activity Theory can be applied to mitigate these risks by reducing the opportunities for cyber crime to occur, making cyber crime more difficult to commit and by increasing the risks of detection and punishment associated with committing cyber crime. Potential research questions are also identified.     

Learning curve models and applications: Literature review and research directions

Learning curves (LCs) are deemed effective tools for monitoring the performance of workers exposed to a new task. LCs provide a mathematical representation of the learning process that takes place as task repetition occurs. These curves were originally proposed by Wright in 1936 upon observing cost reduction due to repetitive procedures in production plants. Since then, LCs have been used to estimate the time required to complete production runs and the reduction in production costs as learning takes place, as well as to assign workers to tasks based on their performance profile. Further, effects of task interruption on workers’ performance have also being modeled by modifications on the LCs. This wide variety of applications justifies the relevance of LCs in industrial applications. This paper presents the state of the art in the literature on learning and forgetting curves, describing the existing models, their limitations, and reported applications. Directions for future research on the subject are eventually proposed.

Relevance to industry

The Learning Curve (LC) models described here can be used in a wide variety of industrial applications where workers endeavor new tasks. LC modeling enables better assignment of tasks to workers and more efficient production planning, and reduces production costs.     

Some interesting research directions in satisfiability

The satisfiability problem and algorithms for solving it have received greatly increased attention in the last few years. This interest comes from a variety of disciplines such as Computer Science, Operations Research, Graph Theory, and Physics, among others. This paper shows some of the current interesting directions in satisfiability research from these disciplines and presents some possible future directions. This revised version was published online in June 2006 with corrections to the Cover Date.     

Time and information technology in teams: a review of empirical research and future research directions

Information technology (IT) is intricately bound up with time in teams. Yet a comprehensive review of what is known about time in IT-mediated teams is lacking. This paper addresses this gap. We classify time into three categories: conceptions of time, mapping activities to time, and actors relating to time. Drawing upon this framework, we review empirical information systems (IS) research on IT-mediated teams over the past three decades. Our review reveals that the research has approached time predominantly using the clock view and has examined exclusively how to map a single activity to the continuum of time. As a result, most studies operate within a simplified temporal context by conceiving time as an objective attribute that ticks away. Meanwhile, a void exists in research that recognizes time as interpretive and experienced. Our analyses also indicate that past research has been primarily interested in the differences between face-to-face and IT-mediated teams and the communication function of IT. Overall, IT remains roughly conceptualized, and research has produced fragmented insights that have small cumulative effects. To advance more substantive theory building, we propose several research directions that invite richer theorizing about how IT is related to time in teams.     

Current and future research directions in network optimization

In this paper, we discuss a number of current and future research directions in network optimization. First, we categorize current research efforts as primarily methodological or primarily applied and we carefully define the boundaries of each class. In addition, we survey the present capabilities of network algorithms. Next, we delineate objectives in each class. Finally, we list several network problems for each class that should, in our opinion, be investigated and we give pertinent background information.     

Cross-layer routing metrics for mesh networks: Current status and research directions

Despite efforts to improve the current IEEE 802.11 standard to fully optimize the physical layer, the performance of wireless mesh networks still depends on the routing process for a correct selection of routes. With regard to this question, several cross-layer routing metrics have been developed to improve wireless multi-hop mesh routing. This paper sets out a new taxonomy that can be used to help understand, classify and compare the state-of-the-art situation with regard to cross-layer routing metrics for wireless mesh networks. A simulation study has been carried out to evaluate the capability of the most recent and promising cross-layer routing metrics to support multimedia applications, such as Voice over IP. The evaluation of the routing metrics has been undertaken from three main perspectives: user perception, network performance, and routing stability. The simulation results show that the impact of routing metrics is more noticeable on the network and routing stability evaluation parameters than on the user-perception parameters. Furthermore, the results show that the routing metrics, the level of stability attained, and the application performance are interdependent. Finally, there is a discussion of the direction that future research might take with regard to some open issues in the design of routing metrics for wireless mesh networks.     

Mediated social touch: a review of current research and future directions

In this paper, we review research and applications in the area of mediated or remote social touch. Whereas current communication media rely predominately on vision and hearing, mediated social touch allows people to touch each other over a distance by means of haptic feedback technology. Overall, the reviewed applications have interesting potential, such as the communication of simple ideas (e.g., through Hapticons), establishing a feeling of connectedness between distant lovers, or the recovery from stress. However, the beneficial effects of mediated social touch are usually only assumed and have not yet been submitted to empirical scrutiny. Based on social psychological literature on touch, communication, and the effects of media, we assess the current research and design efforts and propose future directions for the field of mediated social touch.     

Location privacy models in mobile applications: conceptual view and research directions

Location privacy in mobile, location-aware applications is a prominent research topic spanning across different disciplines and with strong societal implications and expectations. The tumultuous growth of the mobile applications market over the past few years has however hindered the development of a systematic organization and classification of location privacy concepts. In this paper we focus on one of the key concepts, i.e. location privacy metric. We survey existing approaches to the measurement of location privacy and propose a classification framework. The notion of location privacy metric, however, cannot be fully understood without describing the context in which these metrics are used. To that extent we elaborate on the notions of application model and privacy model. The ultimate goal is to contribute to the specification of a conceptual framework for location privacy.     

Swarm intelligence based routing protocol for wireless sensor networks: Survey and future directions

Swarm intelligence is a relatively novel field. It addresses the study of the collective behaviors of systems made by many components that coordinate using decentralized controls and self-organization. A large part of the research in swarm intelligence has focused on the reverse engineering and the adaptation of collective behaviors observed in natural systems with the aim of designing effective algorithms for distributed optimization. These algorithms, like their natural systems of inspiration, show the desirable properties of being adaptive, scalable, and robust. These are key properties in the context of network routing, and in particular of routing in wireless sensor networks. Therefore, in the last decade, a number of routing protocols for wireless sensor networks have been developed according to the principles of swarm intelligence, and, in particular, taking inspiration from the foraging behaviors of ant and bee colonies. In this paper, we provide an extensive survey of these protocols. We discuss the general principles of swarm intelligence and of its application to routing. We also introduce a novel taxonomy for routing protocols in wireless sensor networks and use it to classify the surveyed protocols. We conclude the paper with a critical analysis of the status of the field, pointing out a number of fundamental issues related to the (mis) use of scientific methodology and evaluation procedures, and we identify some future research directions.     

Cyberbullying on social networking sites: A literature review and future research directions

Cyberbullying on social networking sites is an emerging societal issue that has drawn significant scholarly attention. The purpose of this study is to consolidate the existing knowledge through a literature review and analysis. We first discuss the nature, research patterns, and theoretical foundations. We then develop an integrative framework based on social cognitive theory to synthesize what is known and identify what remains to be learned, with a focus on the triadic reciprocal relationships between perpetrators, victims, and bystanders. We discuss the key findings and highlight opportunities for future research. We conclude this paper by noting research contributions and limitations.