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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
An M-BCJR algorithm is proposed and tested over an AWGN channel with moderate to very intense intersymbol interference (ISI). Two M-BCJR applications are evaluated, simple detection over the ISI channel and turbo equalization. The signaling is binary faster than Nyquist linear modulation. The ISI models tested correspond to transmission of increasingly many bits/Hz-s with a fixed signal spectra; t
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
The goal of the paper is to present a distributed scheme to resolving a single path routing problem in multidomain networks. The global problem is formulated as a mixed-integer program (MIP) and approached by means of branch-and-price (B&P). Problems associated with a B&P tree nodes are decomposed using the Dantzig-Wolfe method to a set of domain subproblems coordinated by a single master
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.
In large software organizations with a product line development approach, system test planning and scope selection is a complex tasks for which tool support is needed. Due to repeated testing: across different testing levels, over time (test for regression) as well as of different variants, the risk of double testing is large as well as the risk of overlooking important tests, hidden by the huge a
This paper presents a data-aided Carrier Frequency Offset (CFO) estimation algorithm targeting the Wideband OFDM systems. Utilizing 3 consecutive preambles and processing them at frequency domain, the algorithm is robust to both Frequency Independent (F-I) and Frequency Dependent (F-D) I/Q Mismatch (I/Q-M). To evaluate the effectiveness of the proposed CFO estimation technique, we conduct extensiv
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
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
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
