Adaptive cache aware multiprocessor scheduling framework

Computer resource allocation represents a significant challenge particularly for multiprocessor systems, which consist of shared computing resources to be allocated among co-runner processes and threads. While an efficient resource allocation would result in a highly efficient and stable overall multiprocessor system and individual thread performance, ineffective poor resource allocation causes significant performance bottlenecks even for the system with high computing resources. This thesis proposes a cache aware adaptive closed loop scheduling framework as an efficient resource allocation strategy for the highly dynamic resource management problem, which requires instant estimation of highly uncertain and unpredictable resource patterns. Many different approaches to this highly dynamic resource allocation problem have been developed but neither the dynamic nature nor the time-varying and uncertain characteristics of the resource allocation problem is well considered. These approaches facilitate either static and dynamic optimization methods or advanced scheduling algorithms such as the Proportional Fair (PFair) scheduling algorithm. Some of these approaches, which consider the dynamic nature of multiprocessor systems, apply only a basic closed loop system; hence, they fail to take the time-varying and uncertainty of the system into account. Therefore, further research into the multiprocessor resource allocation is required. Our closed loop cache aware adaptive scheduling framework takes the resource availability and the resource usage patterns into account by measuring time-varying factors such as cache miss counts, stalls and instruction counts. More specifically, the cache usage pattern of the thread is identified using QR recursive least square algorithm (RLS) and cache miss count time series statistics. For the identified cache resource dynamics, our closed loop cache aware adaptive scheduling framework enforces instruction fairness for the threads. Fairness in the context of our research project is defined as a resource allocation equity, which reduces corunner thread dependence in a shared resource environment. In this way, instruction count degradation due to shared cache resource conflicts is overcome. In this respect, our closed loop cache aware adaptive scheduling framework contributes to the research field in two major and three minor aspects. The two major contributions lead to the cache aware scheduling system. The first major contribution is the development of the execution fairness algorithm, which degrades the co-runner cache impact on the thread performance. The second contribution is the development of relevant mathematical models, such as thread execution pattern and cache access pattern models, which in fact formulate the execution fairness algorithm in terms of mathematical quantities. Following the development of the cache aware scheduling system, our adaptive self-tuning control framework is constructed to add an adaptive closed loop aspect to the cache aware scheduling system. This control framework in fact consists of two main components: the parameter estimator, and the controller design module. The first minor contribution is the development of the parameter estimators; the QR Recursive Least Square(RLS) algorithm is applied into our closed loop cache aware adaptive scheduling framework to estimate highly uncertain and time-varying cache resource patterns of threads. The second minor contribution is the designing of a controller design module; the algebraic controller design algorithm, Pole Placement, is utilized to design the relevant controller, which is able to provide desired timevarying control action. The adaptive self-tuning control framework and cache aware scheduling system in fact constitute our final framework, closed loop cache aware adaptive scheduling framework. The third minor contribution is to validate this cache aware adaptive closed loop scheduling framework efficiency in overwhelming the co-runner cache dependency. The timeseries statistical counters are developed for M-Sim Multi-Core Simulator; and the theoretical findings and mathematical formulations are applied as MATLAB m-file software codes. In this way, the overall framework is tested and experiment outcomes are analyzed. According to our experiment outcomes, it is concluded that our closed loop cache aware adaptive scheduling framework successfully drives co-runner cache dependent thread instruction count to co-runner independent instruction count with an error margin up to 25% in case cache is highly utilized. In addition, thread cache access pattern is also estimated with 75% accuracy.

Infrastructure transitions toward sustainability : a complex adaptive systems perspective

To ensure infrastructure assets are procured and maintained by government on behalf of citizens, appropriate policy and institutional architecture is needed, particularly if a fundamental shift to more sustainable infrastructure is the goal. The shift in recent years from competitive and resource-intensive procurement to more collaborative and sustainable approaches to infrastructure governance is considered a major transition in infrastructure procurement systems. In order to better understand this transition in infrastructure procurement arrangements, the concept of emergence from Complex Adaptive Systems (CAS) theory is offered as a key construct. Emergence holds that micro interactions can result in emergent macro order. Applying the concept of emergence to infrastructure procurement, this research examines how interaction of agents in individual projects can result in different industry structural characteristics. The paper concludes that CAS theory, and particularly the concept of ‘emergence’, provides a useful construct to understand infrastructure procurement dynamics and progress towards sustainability.

Understanding IT value : a multilevel, complex, and adaptive system perspective

One remaining difficulty in the Information Technology (IT) business value evaluation domain is the direct linkage between IT value and the underlying determinants of IT value or surrogates of IT value. This paper proposes a research that examines the interacting effects of the determinants of IT value, and their influences on IT value. The overarching research question is how those determinants interact with each other and affect the IT value at organizational value. To achieve this, this research embraces a multilevel, complex, and adaptive system view, where the IT value emerges from the interacting of underlying determinants. This research is theoretically grounded on three organizational theories – multilevel theory, complex adaptive systems theory, and adaptive structuration theory. By integrating those theoretical paradigms, this research proposes a conceptual model that focuses on the process where IT value is created from interactions of those determinants. To answer the research question, agent-based modeling technique is used in this research to build a computational representation based on the conceptual model. Computational experimentation will be conducted based on the computational representation. Validation procedures will be applied to consolidate the validity of this model. In the end, hypotheses will be tested using computational experimentation data.

Adaptive compliance control of a multi‐legged stair‐climbing robot based on proprioceptive data

Purpose – The purpose of this paper is to describe an innovative compliance control architecture for hybrid multi‐legged robots. The approach was verified on the hybrid legged‐wheeled robot ASGUARD, which was inspired by quadruped animals. The adaptive compliance controller allows the system to cope with a variety of stairs, very rough terrain, and is also able to move with high velocity on flat ground without changing the control parameters. Design/methodology/approach – The paper shows how this adaptivity results in a versatile controller for hybrid legged‐wheeled robots. For the locomotion control we use an adaptive model of motion pattern generators. The control approach takes into account the proprioceptive information of the torques, which are applied on the legs. The controller itself is embedded on a FPGA‐based, custom designed motor control board. An additional proprioceptive inclination feedback is used to make the same controller more robust in terms of stair‐climbing capabilities. Findings – The robot is well suited for disaster mitigation as well as for urban search and rescue missions, where it is often necessary to place sensors or cameras into dangerous or inaccessible areas to get a better situation awareness for the rescue personnel, before they enter a possibly dangerous area. A rugged, waterproof and dust‐proof corpus and the ability to swim are additional features of the robot. Originality/value – Contrary to existing approaches, a pre‐defined walking pattern for stair‐climbing was not used, but an adaptive approach based only on internal sensor information. In contrast to many other walking pattern based robots, the direct proprioceptive feedback was used in order to modify the internal control loop, thus adapting the compliance of each leg on‐line.

Surface effects on spinwave resonance in thin magnetic films

Over the past few decades, ferromagnetic spinwave resonance in magnetic thin films has been used as a tool for studying the properties of magnetic materials. A full understanding of the boundary conditions at the surface of the magnetic material is extremely important. Such an understanding has been the general objective of this thesis. The approach has been to investigate various hypotheses of the surface condition and to compare the results of these models with experimental data. The conclusion is that the boundary conditions are largely due to thin surface regions with magnetic properties different from the bulk. In the calculations these regions were usually approximated by uniform surface layers; the spins were otherwise unconstrained except by the same mechanisms that exist in the bulk (i.e., no special "pinning" at the surface atomic layer is assumed). The variation of the ferromagnetic spinwave resonance spectra in YIG films with frequency, temperature, annealing, and orientation of applied field provided an excellent experimental basis for the study.

This thesis can be divided into two parts. The first part is ferromagnetic resonance theory; the second part is the comparison of calculated with experimental data in YIG films. Both are essential in understanding the conclusion that surface regions with properties different from the bulk are responsible for the resonance phenomena associated with boundary conditions.

The theoretical calculations have been made by finding the wave vectors characteristic of the magnetic fields inside the magnetic medium, and then combining the fields associated with these wave vectors in superposition to match the specified boundary conditions. In addition to magnetic boundary conditions required for the surface layer model, two phenomenological magnetic boundary conditions are discussed in detail. The wave vectors are easily found by combining the Landau-Lifshitz equations with Maxwell's equations. Mode positions are most easily predicted from the magnetic wave vectors obtained by neglecting damping, conductivity, and the displacement current. For an insulator where the driving field is nearly uniform throughout the sample, these approximations permit a simple yet accurate calculation of the mode intensities. For metal films this calculation may be inaccurate but the mode positions are still accurately described. The techniques necessary for calculating the power absorbed by the film under a specific excitation including the effects of conductivity, displacement current and damping are also presented.

In the second part of the thesis the properties of magnetic garnet materials are summarized and the properties believed associated with the two surface regions of a YIG film are presented. Finally, the experimental data and calculated data for the surface layer model and other proposed models are compared. The conclusion of this study is that the remarkable variety of spinwave spectra that arises from various preparation techniques and subsequent treatments can be explained by surface regions with magnetic properties different from the bulk.

Change escalation processes and complex adaptive systems: from incremental reconfigurations to discontinuous restructuring

This study examines when “incremental” change is likely to trigger “discontinuous” change, using the lens of complex adaptive systems theory. Going beyond the simulations and case studies through which complex adaptive systems have been approached so far, we study the relationship between incremental organizational reconfigurations and discontinuous organizational restructurings using a large-scale database of U.S. Fortune 50 industrial corporations. We develop two types of escalation process in organizations: accumulation and perturbation. Under ordinary conditions, it is perturbation rather than the accumulation that is more likely to trigger subsequent discontinuous change. Consistent with complex adaptive systems theory, organizations are more sensitive to both accumulation and perturbation in conditions of heightened disequilibrium. Contrary to expectations, highly interconnected organizations are not more liable to discontinuous change. We conclude with implications for further research, especially the need to attend to the potential role of managerial design and coping when transferring complex adaptive systems theory from natural systems to organizational systems.

Hydrogen bond and the resonance effect on the formamide-water complexes

The interaction of formamide and the two transition states of its amide group rotation with one, two, or three water molecules was studied in vacuum. Great differences between the electronic structure of formamide in its most stable form and the electronic structure of the transition states were noticed. Intermolecular interactions were intense, especially in the cases where the solvent interacted with the amide and the carbonyl groups simultaneously. In the transition states, the interaction between the lone pair of nitrogen and the water molecule becomes important. With the aid of the natural bond orbitals, natural resonance theory, and electron localization function (ELF) analyses an increase in the resonance of planar formamide with the addition of successive water molecules was observed. Such observation suggests that the hydrogen bonds in the formamidewater complexes may have some covalent character. These results are also supported by the quantitative ELF analyses. (C) 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012

Stochastic competitive learning in complex networks

Competitive learning is an important machine learning approach which is widely employed in artificial neural networks. In this paper, we present a rigorous definition of a new type of competitive learning scheme realized on large-scale networks. The model consists of several particles walking within the network and competing with each other to occupy as many nodes as possible, while attempting to reject intruder particles. The particle's walking rule is composed of a stochastic combination of random and preferential movements. The model has been applied to solve community detection and data clustering problems. Computer simulations reveal that the proposed technique presents high precision of community and cluster detections, as well as low computational complexity. Moreover, we have developed an efficient method for estimating the most likely number of clusters by using an evaluator index that monitors the information generated by the competition process itself. We hope this paper will provide an alternative way to the study of competitive learning.

Strategic development process and complex adaptive systems

The two areas of theory upon which this research was based were „strategy development process?(SDP) and „complex adaptive systems? (CAS), as part of complexity theory, focused on human social organisations. The literature reviewed showed that there is a paucity of empirical work and theory in the overlap of the two areas, providing an opportunity for contributions to knowledge in each area of theory, and for practitioners. An inductive approach was adopted for this research, in an effort to discover new insights to the focus area of study. It was undertaken from within an interpretivist paradigm, and based on a novel conceptual framework. The organisationally intimate nature of the research topic, and the researcher?s circumstances required a research design that was both in-depth and long term. The result was a single, exploratory, case study, which included use of data from 44 in-depth, semi-structured interviews, from 36 people, involving all the top management team members and significant other staff members; observations, rumour and grapevine (ORG) data; and archive data, over a 5½ year period (2005 – 2010). Findings confirm the validity of the conceptual framework, and that complex adaptive systems theory has potential to extend strategy development process theory. It has shown how and why the strategy process developed in the case study organisation by providing deeper insights to the behaviour of the people, their backgrounds, and interactions. Broad predictions of the „latent strategy development? process and some elements of the strategy content are also possible. Based on this research, it is possible to extend the utility of the SDP model by including peoples? behavioural characteristics within the organisation, via complex adaptive systems theory. Further research is recommended to test limits of the application of the conceptual framework and improve its efficacy with more organisations across a variety of sectors.

Identifying the knowledge management structures in enterprise systems projects

Enterprise System (ES) implementation and management are knowledge intensive tasks that inevitably draw upon the experience of a wide range of people with diverse knowledge capabilities. Knowledge Management (KM) has been identified as a critical success factor in ES projects. Despite the recognized importance of managing knowledge for ES benefits realization, systematic attempts to conceptualize KM-structures have been few. Where the adequacy of KM-structures is assessed, the process and measures are typically idiosyncratic and lack credibility. Using the ‘KM-process’, itself based in sociology of knowledge, this paper conceptualizes four main constructs to measure the adequacy of KM-structures. The SEM model is tested using 310 responses gathered from 27 ES installations that had implemented SAP R/3. The findings reveal six constructs for KM-structure. Furthermore, the paper demonstrates the application of KM-structures in the context of ES using the Adaptive Structuration Theory. The results demonstrate that having adequate KM-structures in place, while necessary, is not sufficient. These rules and resources must be appropriated to have greater positive influence on the Enterprise System. Furthermore, the study provides empirical support for knowledge-based theory by illustrating the importance of knowledge use/re-use (vs. knowledge creation) as the most important driver in the process of KM.

A Marxian model of technology appropriation

This paper explores the philosophical roots of appropriation within Marx's theories and socio-cultural studies in an attempt to seek common ground among existing theories of technology appropriation in IS research. Drawing on appropriation perspectives from Adaptive Structuration Theory, the Model of Technology Appropriation and the Structurational Model of Technology for comparison, we aim to generate a Marxian model that provides a starting point toward a general causal model of technology appropriation. This paper opens a philosophical discussion on the phenomenon of appropriation in the IS community, directing attention to foundational concepts in the human-technology nexus using ideas conceived by Marx.

Integrating organisational design with IT design : the Queensland Health payroll case

Most existing requirements engineering approaches focus on the modelling and specification of the IT artefacts ignoring the environment where the application is deployed. Although some requirements engineering approaches consider the stakeholder’s goals, they still focus on the IT artefacts’ specification. However, IT artefacts are embedded in a dynamic organisational environment and their design and specification cannot be separated from the environment’s constant evolution. Therefore, during the initial stages of a requirements engineering process it is advantageous to consider the integration of IT design with organisational design. We proposed the ADMITO (Analysis, Design and Management of IT and Organisations) approach to represent the dynamic relations between social and material entities, where the latter are divided into technological and organisational entities. In this paper we show how by using ADMITO in a concrete case, the Queensland Health Payroll (QHP) case, it is possible to have an integrated representation of IT and organisational design supporting organisational change and IT requirements specification.

Alfven resonances and forced reconnection

The correspondence between the forced magnetic reconnection induced by perturbing the boundary of the simple Taylor model and the surface-wave-induced magnetic reconnection given by Alfven resonance theory is pointed out explicitly by showing that the theory of forced magnetic reconnection is actually embedded in the Alfven resonance theory. The advantages of viewing the forced reconnection as surface-wave-induced reconnection are briefly discussed in the context of the formation of small-scale structures at the magnetospheric boundary and solar coronal heating.

Some observational evidence of Alfven surface waves induced magnetic reconnection

The surface wave induced magnetic reconnection (SWIMR) model based on Alfven Resonance theory will be discussed briefly both for collisional and collisionless plasmas. It is shown that the spatial scales and time delays associated with Flux Transfer Events and Pulsed Ionospheric Flows, as observed by satellites and SuperDARN radars and the magnetic bubbles, observed at the high latitude boundary of the magnetopause, can be explained by the SWIMR model.

Synthetic scope and DFT analysis of the chiral binap-gold(I) complex-catalyzed 1,3-dipolar cycloaddition of azlactones with alkenes

he 1,3-dipolar cycloaddition between glycine-derived azlactones with maleimides is efficiently catalyzed by the dimeric chiral complex [(S-a)-Binap.AuTFA](2). The alanine-derived oxazolone only reacts with tert-butyl acrylate giving anomalous regiochemistry, which is explained and supported by Natural Resonance Theory and Nucleus Independent Chemical Shifts calculations. The origin of the high enantiodiscrimination observed with maleimides and tert-butyl acrylate is analyzed using DFT computed at M06/Lanl2dz//ONIOM(b3lyp/Lanl2dz:UFF) level. Several applications of these cycloadducts in the synthesis of new proline derivatives with a 2,5-trans-arrangement and in the preparation of complex fused polycyclic molecules are described.