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Context: Systems of systems (SoS) are highly complex and are integrated on multiple levels (unit, component, system, system of systems). Many of the characteristics of SoS (such as operational and managerial independence, integration of system into system of systems, SoS comprised of complex systems) make their development and testing challenging. Contribution: This paper provides an understanding

We consider the problem of detecting exploits based on return-oriented programming. In contrast to previous works we investigate to which extent we can detect ROP payloads by only analysing streaming data, i.e., we do not assume any modifications to the target machine, its kernel or its libraries. Neither do we attempt to execute any potentially malicious code in order to determine if it is an att

We present a model for supporting scoping decisions that is based on an analysis of the ROI for a given feature. Employing a ROI threshold value for making scoping decisions, the utility of the model was investigated using data from a single large project and identified a group of outlying features responsible for a disproportionate wasted investment. These initial results are promising and indica

A differential LNA using capacitive shunt feedback is demonstrated in 65nm CMOS. The capacitive shunt feedback structure gives a wideband input matching, S11 <;-17 dB from 500MHz - 1 GHz for low band and S11 <;-20 dB from 1.1 GHz - 2.3GHz for high band. The NF for the complete receiver chain in low band and high band was measured to 3.3 dB and 3.9 dB, respectively. The 1-dB compression point with

We consider the problem of providing trusted computing functionality in high availability systems. We consider the case where data is required to be encrypted with a TPM protected key. For redundancy, and to facilitate high availability, the same TPM key is stored in multiple computational units, each one ready to take over if the main unit breaks down. This requires the TPM key to be migratable.

This paper deals with optimal load balancing in telecommunication networks. For a capacitated telecommunications network with single path routing and an estimated traffic demand matrix, we wish to determine the routing paths aiming at min-max optimization of link loads. To solve this problem, we propose a column (path) generation based heuristic. In the first step, we use column generation to solv

Background: Development of complex, software intensive systems generates large amounts of information. Several researchers have developed tools implementing information retrieval (IR) approaches to suggest traceability links among artifacts. Aim: We explore the consequences of the fact that a majority of the evaluations of such tools have been focused on benchmarking of mere tool output. Method: T

Large-scale software development generates an ever-growing amount of information. Multiple research groups have proposed using approaches from the domain of information retrieval (IR) to recover traceability. Several enhancement strategies have been initially explored using the laboratory model of IR evaluation for performance assessment. We conducted a pilot experiment using printed candidate lis

This paper deals with the joint estimation of spatial mode shapes and temporal frequencies from transient vibrations measured by a uniform circular array of sensors encircling a cross-section of a cylinder. The geometry allows each 2D mode to be interpreted as two real planar waves impinging from mirrored directions with respect to the broadside of a uniform linear array. Algorithms for joint esti

Recent developments in characteristic mode (CM) analysis enable a more systematic approach to designing multi-antennas for mobile terminals. However, some of the advantages of developing antennas through CMs are based on accurate mode tracking over frequency. Existing tracking methods are primarily based on the tracking of eigencurrents over frequency, by which mode swapping and degenerate modes c

The paper is devoted to modeling and optimization of reliable wireless mesh networks that employ directional antennas. We introduce two mixed-integer programming formulations that allow to simultaneously characterize routing patterns and transmission schedules. The first model allows for maximizing the minimal flow in a network. The second model involves reliability constraints and aims at minimiz

Engineers working on safety critical software development must explicitly specify trace links as part of Impact Analyses (IA), both to code and non-code development artifacts. In large-scale projects, constituting information spaces of thousands of artifacts, conducting IA is tedious work relying on extensive system understanding. We propose to support this activity by enabling engineers to reuse

An LTE-enabled smartphone is a software-defined radio system that must cover a large number of frequency bands with different duplex differences. A proposed adaptive wideband duplexer needs a circulator to create the required initial isolation. To replace this an LC-based tunable low-isolation device is presented in this paper, providing the required tuning range for LTE Band I, II, III and VII. T

This study describes a high throughput constant envelope (CE) pre-coder for Massive MIMO systems. A large number of antennas (M), in the order of 100s, serve a relatively small number of users (K) simultaneously. The stringent amplitude constraint (only phase changes) in the CE scheme is motivated by the use of highly power-efficient non-linear RF power amplifiers. We propose a scheme that compute

Test managers have to repeatedly select test cases for test activities during evolution of large software systems. Researchers have widely studied automated test scoping, but have not fully investigated decision support with human interaction. We previously proposed the introduction of visual analytics for this purpose. Aim: In this empirical study we investigate how to design such decision suppor

A Multi-band CMOS front-end was designed and fabricated in a 0.13μm CMOS process. The front-end employs a common-gate low noise amplifier (LNA) with capacitive cross coupling (CCC) technique and a double balanced mixer. The band selection is performed by switching capacitors in and out of the LNA load, changing the resonance frequencies ranging from 2.5GHz to 4.5GHz in 16 different frequency bands