A survey of opponent modeling techniques in automated negotiation

A negotiation between agents is typically an incomplete information game, where the agents initially do not know their opponent’s preferences or strategy. This poses a challenge, as efficient and effective negotiation requires the bidding agent to take the other’s wishes and future behavior into account when deciding on a proposal. Therefore, in order to reach better and earlier agreements, an agent can apply learning techniques to construct a model of the opponent. There is a mature body of research in negotiation that focuses on modeling the opponent, but there exists no recent survey of commonly used opponent modeling techniques. This work aims to advance and integrate knowledge of the field by providing a comprehensive survey of currently existing opponent models in a bilateral negotiation setting. We discuss all possible ways opponent modeling has been used to benefit agents so far, and we introduce a taxonomy of currently existing opponent models based on their underlying learning techniques. We also present techniques to measure the success of opponent models and provide guidelines for deciding on the appropriate performance measures for every opponent model type in our taxonomy

Consensus guidelines for the use and interpretation of angiogenesis assays

The formation of new blood vessels, or angiogenesis, is a complex process that plays important roles in growth and development, tissue and organ regeneration, as well as numerous pathological conditions. Angiogenesis undergoes multiple discrete steps that can be individually evaluated and quantified by a large number of bioassays. These independent assessments hold advantages but also have limitations. This article describes in vivo, ex vivo, and in vitro bioassays that are available for the evaluation of angiogenesis and highlights critical aspects that are relevant for their execution and proper interpretation. As such, this collaborative work is the first edition of consensus guidelines on angiogenesis bioassays to serve for current and future reference

Predicting the performance of opponent models in automated negotiation

When two agents settle a mutual concern by negotiating with each other, they usually do not share their preferences so as to avoid exploitation. In such a setting, the agents may need to analyze each other's behavior to make an estimation of the opponent's preferences. This process of opponent modeling makes it possible to find a satisfying negotiation outcome for both parties. A large number of such opponent modeling techniques have already been introduced, together with different measures to assess their quality. The quality of an opponent model can be measured in two different ways: one is to use the agent's performance as a benchmark for the model's quality, the other is to directly evaluate its accuracy by using similarity measures. Both methods have been used extensively, and both have their distinct advantages and drawbacks. In this work we investigate the exact relation between the two, and we pinpoint the measures for accuracy that best predict performance gain. This leads us to new insights in how to construct an opponent model, and what we need to measure when optimizing performanc

Decoupling negotiating agents to explore the space of negotiation strategies

Every year, automated negotiation agents are improving on various domains. However, given a set of automated negotiation agents, current methods allow to determine which strategy is best in terms of utility, but not so much the reason of success. In order to study the performance of the individual components of a negotiation strategy, we introduce an architecture that distinguishes three components which together constitute a negotiation strategy: the bidding strategy, the opponent model, and the acceptance strategy. Our contribution to the field of bilateral negotiation is twofold: first, we show that existing state-of-the-art agents are compatible with this architecture by re-implementing them in the new framework; secondly, as an application of our architecture, we systematically explore the space of possible strategies by recombining different strategy components, resulting in negotiation strategies that improve upon the current state-of-the-art in automated negotiation

Decoupling negotiating agents to explore the space of negotiation strategies

Every year, automated negotiation agents are improving on various domains. However, given a set of automated negotiation agents, current methods allow to determine which strategy is best in terms of utility, but not so much the reason of success. In order to study the performance of the individual components of a negotiation strategy, we introduce an architecture that distinguishes three components which together constitute a negotiation strategy: the bidding strategy, the opponent model, and the acceptance strategy. Our contribution to the field of bilateral negotiation is twofold: first, we show that existing state-of-the-art agents are compatible with this architecture by re-implementing them in the new framework; secondly, as an application of our architecture, we systematically explore the space of possible strategies by recombining different strategy components, resulting in negotiation strategies that improve upon the current state-of-the-art in automated negotiation

Structured hypermedia authoring: a simple tool for the design and implementation of structured hypermedia databases

© Springer-Verlag Berlin Heidelberg 1996. In this paper a new hypermedia model is presented that avoids a number of traditional problems of hypermedia authoring, and facilitates the maintenance of links and the re-use of information resources. The model was inspired by problems we experienced while implementing a hypermedia self study course on computer science [Olivié 1993]. It allows pre-structuring of hypertext, which is especially important for educational hypertext, and it allows the inclusion of semantic information which makes querying possible. We also describe a hypermedia authoring system that was developed with this model in mind. It can manage and export hypertext information webs for the World-Wide Web or other hypermedia systems. Examples are given of how we have used the model and the authoring system to implement a hypermedia course.status: publishe

Building Hypermedia with Objects and Sets

In this paper, we present a data model for hypermedia structuring and navigation. The three fundamental building blocks are values, objects and sets, for modeling atomic and aggregate content, as well as navigational structure. In order to formally define operators that enable an end user to access elements of a set, zoom in on or out of a set, we introduce the concepts of user state, topology of a set and anchors

Towards en electronic performance support system for university teachers: DigIT

status: publishe

Object-oriented hypertext design: authoring for reuse

In this paper we present a new approach for the development of hypertext information systems that avoids a number of traditional hypermedia authoring problems, and facilitates the maintenance of links and the reuse of information resources. The model is set-based, and integrates features from object-oriented software design models. This helps authors to make a comprehensive (and comprehensible) design before starting an implementation. We also briefly describe an authoring system that implements this model, and which uses an existing relational database system to store documents, links and meta-information.Book subtitle: INFORMATION SYSTEMS TRACK - ORGANIZATIONAL SYSTEMS AND TECHNOLOGYstatus: publishe

Structure and processes of emergency observation units with a geriatric focus: a scoping review

Combining observation principles and geriatric care concepts is considered a promising strategy for risk-stratification of older patients with emergency care needs. We aimed to map the structure and processes of emergency observation units (EOUs) with a geriatric focus and explore to what extent the comprehensive geriatric assessment (CGA) approach was implemented in EOUs.; The revised scoping methodology framework of Arksey and O'Malley was applied. Manuscripts reporting on dedicated areas within hospitals for observation of older patients with emergency care needs were eligible for inclusion. Electronic database searches were performed in MEDLINE, EMBASE and CINAHL in combination with backward snowballing. Two researchers conducted data charting independently. Data-charting forms were developed and iteratively refined. Data inconsistencies were judged by a third researcher or discussed in the research team. Quality assessment was conducted with the Methodological Index for Non-Randomized Studies.; Sixteen quantitative studies were included reporting on fifteen EOUs in seven countries across three continents. These units were located in the ED, immediately next to the ED or remote from the ED (i.e. hospital-based). All studies reported that staffing consisted of at least three healthcare professions. Observation duration varied between 4 and 72 h. Most studies focused on medical and functional assessment. Four studies reported to assess a patients' medical, functional, cognitive and social capabilities. If deemed necessary, post-discharge follow-up (e.g. community/primary care services and/or outpatient clinics) was provided in eleven studies.; This scoping review documented that the structure and processes of EOUs with a geriatric focus are very heterogeneous and rarely cover all elements of CGA. Further research is necessary to determine how complex care principles of 'observation medicine' and 'CGA' can ideally be merged and successfully implemented in clinical care