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Communicate! is a serious game for practicing communication skills. It supports practicing interpersonal communication skills between a health care professional such as a doctor or a pharmacist, or a (business) psychologist, and a patient or client. A player selects a scenario, and holds a consultation with a virtual character. In the consultation, the player chooses between the various options offered in the scenario. The player scores on the learning goals addressed by the scenario, and gets immediate feedback through the effect of the choice between the answer options on the utterance and emotion of the virtual character. Communicate! also offers an editor for scenarios. A scenario is a graph-like structure, extended with several constructs to avoid the development of repetitive structures. We have performed several experiments with Communicate!, both with students to evaluate the use of Communicate! in various programs at Utrecht University, and with teachers to evaluate the development of scenarios for Communicate!

This paper presents a Learning Analytics approach for understanding the learning behavior of students while interacting with Technology Enhanced Learning tools. In this work we show that it is possible to gain insight into the learning processes of students from their interaction data. We base our study on data collected through six laboratory sessions where first-year students of Computer Engineering at the University of Genoa were using a digital electronics simulator. We exploit Process Mining methods to investigate and compare the learning processes of students. For this purpose, we measure the understandability of their process models through a complexity metric. Then we compare the various clusters of students based on their academic achievements. The results show that the measured complexity has positive correlation with the final grades of students and negative correlation with the difficulty of the laboratory sessions. Consequently, complexity of process models can be used as an indicator of variations of student learning paths.

The German mirror committee of ISO TC147 SC 5 WG 9 ‘Genotoxicity’ organised an international round robin study on the Ames fluctuation test (ISO DIS 11350). Nineteen laboratories from seven countries participated in the study. The laboratories had to test four coded water samples. Sample one, a river water sample, was used as a negative control water sample and for spiking with strain-specific mixtures of mutagens (samples two and three). Sample four was an effluent from an industrial waste water plant. Validity criteria were fulfilled in 86 to 100 % of all test conditions (bacterial strain / }; S9-mix). The overall test sensitivity was 100 %. The test specificity ranged from 80 to 100 % depending on the test condition. For statistical evaluation an arcsinsquare- root transformation was applied to generate a metric data set. An ANOVA was performed to identify samples with a significantly higher numbers of revertants. A threshold value derived from a large set of negative controls was used in a final step to exclude results of individual tests with unexpected low numbers of spontaneous revertants. The lowest ineffective dilution values (LIDs) were then determined by this new approach. The variability of the LID values among the laboratories amounted in most cases to no more than two dilution steps around the median. The data produced in this round robin study proved a sufficient reproducibility of the test procedure and provide validity data for the finalization of the ISO standardization process.

Learning Analytics (LA) dashboards help raise student and teacher awareness regarding learner activities. In blog-supported and inquiry-based learning courses, LA data is not limited to student activities, but also contains an abundance of digital learner artefacts, such as blog posts, hypotheses, and mind-maps. Exploring peer activities and artefacts can help students gain new insights and perspectives on learning efforts and outcomes, but requires effort. To help facilitate facilitate and promote this exploration, we present the lessons learnt during and guidelines derived from the design, deployment and evaluation of five dashboards. ispartof: pages:42-56 ispartof: Adaptive and Adaptable Learning vol:9891 pages:42-56 ispartof: European Conference on Technology Enhanced Learning location:Lyon, France date:13 Sep - 16 Sep 2016 status: published

This paper provides an overview of the Privilege Management Infrastructure (PMI) introduced in the 2000 edition of X.509. It describes the entities in the infrastructure: Sources of Authority, Attribute Authorities and Privilege Holders, as well as the basic data structure - the attribute certificate - that is used to hold privileges. The contents of attribute certificates are described in detail, including the various policy related extensions that may be added to them. The similarities between PMIs and PKIs are highlighted. The paper also describes how attribute certificates can be used to implement the three well known access control schemes: DAC, MAC and RBAC. Finally the paper gives an overview of how a privilege verifier might operate, and the various types of information that need to be provided to it.

This paper describes the PERMIS role based access control infrastructure that uses X.509 attribute certificates (ACs) to store the users roles. Users roles can be assigned by multiple widely distributed management authorities (called Attribute Authorities in X.509), thereby easing the burden of management. All the ACs can be stored in one or more LDAP directories, thus making them widely available. The PERMIS distribution includes a Privilege Allocator GUI tool, and a bulk loader tool, that allow administrators to construct and sign ACs and store them in an LDAP directory ready for use by the PERMIS decision engine. All access control decisions are driven by an authorization policy, which is itself stored in an X.509 AC, thus guaranteeing its integrity and trustworthiness. Authorization policies are written in XML according to a DTD that has been published at XML.org. A user friendly policy management tool is also being built that will allow non- technical managers to easily specify PERMIS authorisation policies. The access control decision engine is written in Java and has both a Java API and SAML-SOAP interface, allowing it to be called either locally or remotely. The Java API is simple to use, comprising of just 3 methods and a constructor. The SAML-SOAP interface conforms to the OASIS SAMLv1.1 specification, as profiled by a Global Grid Forum draft standard, thus making PERMIS suitable as an authorisation server for Grid applications.

This paper shows that the scheme described in Haber and Stornetta [Haber and Stornetta Jr., 1994] for extending the validity of a cryptographic timestamp for a Time Stamping Service contains security shortcomings. A modification is proposed to rectify the identified shortcomings.

Certain undesirable features are identified in the ‘Structural proven signer ordering’ multisignature scheme of Kotzanikolaou, Burmester and Chrissikopoulos. This scheme is a modification of a previous multisignature scheme due to Mitomi and Miyaji.

The Internet White Pages Service has been slow to materialise for many reasons. One of them is the security concerns that organisations have, over allowing the public to gain access to either their Intranet or their directory database. The Guardian DSA is a firewall application proxy for X.500 and LDAP protocols that is designed to alleviate these fears. Sitting in the firewall system, it filters directory protocol messages passing into and out of the Intranet, allowing security administrators to carefully control the amount of directory information that is released to the outside world. This paper describes the design of our Guardian system, and shows how relatively easy it is to configure its filtering capabilities. Finally the paper describes the working demonstration of the Guardian that was built for the 1997 World Electronic Messaging Association directory challenge. This linked the WEMA directory to the NameFLOW-Paradise Internet directory, and demonstrated some of the powerful filtering capabilities of the Guardian. This paper was originally presented at The Internet Society 1998 Symposium on Network and Distributed Systems Security (NDSS 98), March 10-12, San Diego, California

A project to enable health care professionals (GPs, practice nurses and diabetes nurse specialists) to access, via the Internet, confidential patient data held on a secondary care (hospital) diabetes information system, has been implemented. We describe the application that we chose to distribute (a diabetes register); the security mechanisms we used to protect the data (a public key infrastructure with strong encryption and digitally signed messages, plus a firewall); the reasons for the implementation decisions we made; the validation testing that we performed and the preliminary results of the pilot implementation.

This paper describes the mechanisms that are needed in order to provide a secure directory service based on the X.500 data model. A brief introduction to the X.500 data model is given followed by an overview of the Lightweight Directory Access Protocol. Security can be provided by three functions: an application level firewall, an authentication mechanism, and an access control scheme. A description of the X.500 and LDAP access control models is presented followed by the authentication methods that have been standardised for LDAPv3. A companion paper describes a directory application firewall.