Toward Anonymity in Delay Tolerant Networks: Threshold Pivot Scheme

Proceedings of the Military Communications Conference (MILCOM 2010), San Jose, CA, October 2010.Delay Tolerant Networks (DTNs) remove traditional assumptions of end-to-end connectivity, extending network communication to intermittently connected mobile, ad-hoc, and vehicular environments. This work considers anonymity as a vital security primitive for viable military and civilian DTNs. DTNs present new and unique anonymity challenges since we must protect physical location information as mobile nodes with limited topology knowledge naturally mix. We develop a novel Threshold Pivot Scheme (TPS) for DTNs to address these challenges and provide resistance to traffic analysis, source anonymity, and sender-receiver unlinkability. Reply techniques adapted from mix-nets allow for anonymous DTN communication, while secret sharing provides a configurable level of anonymity that enables a balance between security and efficiency. We evaluate TPS via simulation on real-world DTN scenarios to understand its feasibility, performance, and overhead while comparing the provided anonymity against an analytically optimal model

The black silicon method II: the effect of mask material and loading on the reactive ion etching of deep silicon trenches

Very deep trenches in Si with smooth controllable profiles are etched using a fluorine-based Reactive Ion Etcher(RIE). The effect of various mask materials and loading on the profile is examined using the Black Silicon Method. It is found that most metal layers have an almost infinite selectivity. When the aspect ratio of the trenches is beyond five, RIE lag is found to be an important effect. Evidence is found that this effect is caused by the bowing of incoming ions by the electrical field

Transforming Evolutionary Search into Higher-Level Evolutionary Search by Capturing Problem Structure

The intuitive idea that good solutions to small problems can be reassembled into good solutions to larger problems is widely familiar in many fields including evolutionary computation. This idea has motivated the building-block hypothesis and model-building optimization methods that aim to identify and exploit problem structure automatically. Recently, a small number of works make use of such ideas by learning problem structure and using this information in a particular manner: these works use the results of a simple search process in primitive units to identify structural correlations (such as modularity) in the problem that are then used to redefine the variational operators of the search process. This process is applied recursively such that search operates at successively higher scales of organization, hence multi-scale search. Here, we show for the first time that there is a simple class of (modular) problems that a multi-scale search algorithm can solve in polynomial time that requires super-polynomial time for other methods. We discuss strengths and limitations of the multi-scale search approach and note how it can be developed further

The black silicon method: a universal method for determining the parameter setting of a fluorine-based reactive ion etcher in deep silicon trench etching with profile control

Very deep trenches (up to 200 µm) with high aspect ratios (up to 10) in silicon and polymers are etched using a fluorine-based plasma (SF6/O2/CHF3). Isotropic, positively and negatively (i.e. reverse) tapered as well as fully vertical walls with smooth surfaces are achieved by controlling the plasma chemistry. A convenient way to find the processing conditions needed for a vertical wall is described: the black silicon method. This new procedure is checked for three different reactive ion etchers (RIE), two parallel-plate reactors and a hexode. The influence of the RF power, pressure and gas mixture on the profile will be shown. Scanning electron microscope (SEM) photos are included to demonstrate the black silicon method, the influence of the gases on the profile, and the use of this method in fabricating microelectromechanical systems (MEMS)

Exploring the conditions for inclusive port development: the case of Indonesia

Governments around the world are adopting inclusive growth agendas. The ambition to align economic growth ambitions with broader-based social benefits is increasingly embraced by corporations to limit the ‘negative externalities’ and enhance the ‘positive externalities’ of their operations. Therefore, micro-level corporate strategies and macro-level national ambitions meet at the meso-level of networks and clusters. This requires societal spheres to collaborate and search for alternative governance constellations. In this discourse, port development is only recently receiving attention. In March 2018, ports around the world signed the World Ports Sustainability Program declaration, which aims to contribute to the sustainable development goals (SDGs), whilst a number of national port (master) plans have started to include social along with environmental standards. Extant studies on partnering and stakeholder inclusion in port development are proliferating but are primarily aimed at environmental rather than social (inclusion) issues. This paper adopts an exploratory research design to consider conditions for inclusive port development. A novel taxonomy considers port development as a driver for inclusive growth, where partnerships are the missing link between micro-level business strategies and macro-level effects in the port region and economy at large. This paper shows the first findings and delineates areas for further research

The multiple facilitator:Scientists, sages and rascals

Background. Games are designed to help participants think about, understand, sharpen their problem statement as well as the specific objectives to be achieved to escape the problem situation. When participants prepare for the game (briefing), interact in the simulated environment (gameplay), and self- or jointly reflect about the gameplay they faced in terms of intended and unintended learning experiences (debrief), they benefit or suffer from facilitating that can or cannot fully cater to their needs. To support the participants to explore and resolve the problem situation in order to achieve learning goals, we propose that facilitators can make use of role shifts during gameplay. Method. To capture the role shifts in the gameplay phase we studied game runs of the MicroTech game. The MicroTech game is a free-form game in which participants play the role of top management team or division managers in a multiunit organization. Results. We analyzed the role shifts we experienced as facilitators by elaborating on game events and how we could manage those events differently in future game runs if necessary. We show a need for facilitators to be able to embody multiple roles in the case of policy gaming that are in fit with the different phases, while there is a simultaneous need to shift within phases in order to keep participants moving and stimulating them to work towards the learning goals. Conclusion. Gaming/simulation facilitators should explore what multiplicity is required of them to make the game a success. Although this may seem normal practice to well-prepared and professionally trained facilitators, this may be particularly important for novice facilitators

Use of Evidence-informed Deliberative Processes by Health Technology Assessment Agencies Around The Globe

Background: Evidence-informed deliberative processes (EDPs) were recently introduced to guide health technology assessment (HTA) agencies to improve their processes towards more legitimate decision-making. The EDP framework provides guidance that covers the HTA process, ie, contextual factors, installation of an appraisal committee, selecting health technologies and criteria, assessment, appraisal, and communication and appeal. The aims of this study were to identify the level of use of EDPs by HTA agencies, identify their needs for guidance, and to learn about best practices.Methods: A questionnaire for an online survey was developed based on the EDP framework, consisting of elements that reflect each part of the framework. The survey was sent to members of the International Network of Agencies for Health Technology Assessment (INAHTA). Two weeks following the invitation, a reminder was sent. The data collection took place between September-December 2018. Results: Contact persons from 27 member agencies filled out the survey (response rate: 54%), of which 25 completed all questions. We found that contextual factors to support HTA development and the critical elements regarding conducting and reporting on HTA are overall in place. Respondents indicated that guidance was needed for specific elements related to selecting technologies and criteria, appraisal, and communication and appeal. With regard to best practices, the Canadian Agency for Drugs and Technologies and the National Institute for Health and Care Excellence (NICE, UK) were most often mentioned. Conclusion: This is the first survey among HTA agencies regarding the use of EDPs and provides useful information for further developing a practical guide for HTA agencies around the globe. The results could support HTA agencies in improving their processes towards more legitimate decision-making, as they could serve as a baseline measurement for future monitoring and evaluation