Vision 2023: Turkey’s National Technology Foresight Program – a contextualist description and analysis

This paper describes and analyses Vision 2023 Turkish National Technology Foresight Program. The paper is not about a mere description of the activities undertaken. It analyses the Program from a contextualist perspective, where the Program is considered in its own national and organizational contexts by discussing how the factors in these contexts led to the particular decisions taken and approaches adopted when the exercise was organized, designed and practiced. With the description and analysis of the Vision 2023 Technology Foresight Program, the paper suggests that each Foresight exercise should be considered in its own context. The exercise should be organized, designed and practiced by considering the effects of the external contexts (national, regional and/or corporate) and organizational factors stemming from these different context levels along with the nature of the issue being worked on, which constitute the content of the exercise.Foresight, contextualism, Vision 2023, Turkey, Science and Technology Policy

Experimental Techniques for Static and Dynamic Analysis of Thick Bonding Wires

Thick bonding wires are used in modern power modules as connectors between integrated circuits, carrying current from one circuit to another. They experience high values of current, which generates heat through Joule heating and can lead to various failure mechanisms. Typically used wire materials in industry are aluminum (Al), copper (Cu), and intermetallic compounds of Cu-Al. They are broadly used because of their strength, high thermal conductivity, and low resistivity. This study reports on the influence of thermal loading on the mechanical behaviour of bonding wires. Experimental techniques are developed and introduced in this thesis to analyze quasi-static and dynamic response of bonding wires 300 µm in diameter. First, an experimental technique is developed to measure the quasi-static displacement of bonding wires carrying DC currents. It is then deployed to measure the displacement, as well as peak temperature, of three types of bonding wires, Al, Cu and Aluminum coated Copper (CuCorAl) to study the response under DC current. Secondly, an experimental technique is established and deployed for modal analysis of bonding wires under thermal loading. Experimental results demonstrate a drop in the natural frequency of bonding wires with increased thermal loads. Moreover, a harmonic analysis technique using thermal excitation is developed and applied to analyze the mode shapes and frequency response of bonding wires. Furthermore, an analytical model and a finite element model are used to analyze static and dynamic responses of bonding wires. Numerical and experimental results are compared in this thesis

Asymptotic Security of Control Systems by Covert Reaction: Repeated Signaling Game with Undisclosed Belief

This study investigates the relationship between resilience of control systems to attacks and the information available to malicious attackers. Specifically, it is shown that control systems are guaranteed to be secure in an asymptotic manner by rendering reactions against potentially harmful actions covert. The behaviors of the attacker and the defender are analyzed through a repeated signaling game with an undisclosed belief under covert reactions. In the typical setting of signaling games, reactions conducted by the defender are supposed to be public information and the measurability enables the attacker to accurately trace transitions of the defender's belief on existence of a malicious attacker. In contrast, the belief in the game considered in this paper is undisclosed and hence common equilibrium concepts can no longer be employed for the analysis. To surmount this difficulty, a novel framework for decision of reasonable strategies of the players in the game is introduced. Based on the presented framework, it is revealed that any reasonable strategy chosen by a rational malicious attacker converges to the benign behavior as long as the reactions performed by the defender are unobservable to the attacker. The result provides an explicit relationship between resilience and information, which indicates the importance of covertness of reactions for designing secure control systems.Comment: 8 page

Magnetic Particle Imaging tracks the long-term fate of in vivo neural cell implants with high image contrast.

We demonstrate that Magnetic Particle Imaging (MPI) enables monitoring of cellular grafts with high contrast, sensitivity, and quantitativeness. MPI directly detects the intense magnetization of iron-oxide tracers using low-frequency magnetic fields. MPI is safe, noninvasive and offers superb sensitivity, with great promise for clinical translation and quantitative single-cell tracking. Here we report the first MPI cell tracking study, showing 200-cell detection in vitro and in vivo monitoring of human neural graft clearance over 87 days in rat brain

Simultaneous use of Individual and Joint Regularization Terms in Compressive Sensing: Joint Reconstruction of Multi-Channel Multi-Contrast MRI Acquisitions

Purpose: A time-efficient strategy to acquire high-quality multi-contrast images is to reconstruct undersampled data with joint regularization terms that leverage common information across contrasts. However, these terms can cause leakage of uncommon features among contrasts, compromising diagnostic utility. The goal of this study is to develop a compressive sensing method for multi-channel multi-contrast magnetic resonance imaging (MRI) that optimally utilizes shared information while preventing feature leakage. Theory: Joint regularization terms group sparsity and colour total variation are used to exploit common features across images while individual sparsity and total variation are also used to prevent leakage of distinct features across contrasts. The multi-channel multi-contrast reconstruction problem is solved via a fast algorithm based on Alternating Direction Method of Multipliers. Methods: The proposed method is compared against using only individual and only joint regularization terms in reconstruction. Comparisons were performed on single-channel simulated and multi-channel in-vivo datasets in terms of reconstruction quality and neuroradiologist reader scores. Results: The proposed method demonstrates rapid convergence and improved image quality for both simulated and in-vivo datasets. Furthermore, while reconstructions that solely use joint regularization terms are prone to leakage-of-features, the proposed method reliably avoids leakage via simultaneous use of joint and individual terms. Conclusion: The proposed compressive sensing method performs fast reconstruction of multi-channel multi-contrast MRI data with improved image quality. It offers reliability against feature leakage in joint reconstructions, thereby holding great promise for clinical use.Comment: 13 pages, 13 figures. Submitted for possible publicatio

Probabilistic Modeling of Structural Forces

Since forces acting on structures fluctuate widely with time and space during the lifetime of a structure, variations of the forces should be considered by probability distributions. Probabilistic definition of forces is expressed by random field variables including stochastic parameters. Structural forces are simulated by adopting Normal and Gamma probability distribution functions. The basic model given by JCSS (Joint Committee on Structural Safety) code principles is used as model to take into account the variations. In the simulation of the live loads comprised of sustained and intermittent loads, time intervals are assumed to follow a Poisson process and their distributions are defined by exponential distributions. The simulated loads are evaluated in terms of percentiles, correlation effects, reduction factors and extreme values. Results are compared with those of deterministic model as well. It has been observed that probabilistic model is more realistic and the results can be used in the calculation of specific fractiles like load and resistance factor design