A cross-layer key establishment scheme in wireless mesh networks

Cryptographic keys are necessary to secure communications among mesh clients in wireless mesh networks. Traditional key establishment schemes are implemented at higher layers, and the security of most such designs relies on the complexity of computational problems. Extracting cryptographic keys at the physical layer is a promising approach with information-theoretical security. But due to the nature of communications at the physical layer, none of the existing designs supports key establishment if communicating parties are out of each other's radio range, and all schemes are insecure against man-in-the-middle attacks. This paper presents a cross-layer key establishment scheme where the established key is determined by two partial keys: one extracted at the physical layer and the other generated at higher layers. The analysis shows that the proposed cross-layer key establishment scheme not only eliminates the aforementioned shortcomings of key establishment at each layer but also provides a flexible solution to the key generation rate problem. © 2014 Springer International Publishing Switzerland.

Agency theory, national culture and management Control Systems

Management control system of an organization is the structured facet of management, the formal vehicle by which the management process is executed. In most organizations, systems exist for planning, organizing, directing, controlling and motivating. Depending on the level of appropriateness and quality of the management control systems, the task of management is either facilitated or hindered. The end goal of a management control system is achieving organizational objectives. Because employees (agents) do not always give their best efforts for achieving organizational objectives, management control systems need to strive for aligning goals of agents (e.g., employees, subordinates) with that of principals (e.g., senior management, owners). Agency theory and its extension, principal agent model, provide insights to the problem of goal congruence and suggest remedies, at least in the Western cultural context. Whether the agency theory presumptions, predictions and prescriptions are universally applicable is an important issue in management. Their validity in different cultural contexts is largely unknown. The available literature to date indicates the possibility that agency theory may not be valid in non-western cultures. However, further empirical research is needed in non-western cultures to shed more light to this issue.

Agency theory and culture : implications for research in management control systems

The objective of this paper is to encourage further research into the applicability of agency theory for the study of management control issues of organisations in Asian societies.

A case for cross layer design: the impact of physical layer properties on routing protocol performance in MANETs

In this work we evaluate the performance of routing protocols for mobile ad hoc networks using different physical layer models. The results obtained show that the performance results obtained using idealized models such as the free space propagation model vary significantly when propagation effects such as path loss and shadowing are considered. This difference in performance indicates that optimization is required in the protocol development space that takes into account channel state information (CSI). Such an optimization requires a cross layer approach to be adopted and a framework for protocol performance evaluation to be established. We believe that this work would serve as a first step in this direction. We provide comparative performance results through network simulations.

Management control systems and effectiveness of knowledge sharing

Numerous empirical studies on knowledge management have examined the relative effectiveness of various enablers, such as organizational structure (Bennett and Gabriel, 1999; Gold et aI., 2001), technology (Gold et aI., 2001; O'Dell and Grayson, 1998), culture (DeLong and Fahey, 2000; Gupta and Govindarajan, 2000), managerial system (Nonaka, 1994; Sveiby, 1997) and strategy (Bierly and Chakrabarti, 1996; Holsapple and Joshi, 2001) on knowledge creation and sharing in organizations. Little research has focused on the role of management control systems (MCS) in facilitating knowledge sharing in knowledge-intensive firms (Ditillo, 2004). This study examines how the interactive use of management control systems (MCS) could facilitate the different modes of knowledge sharing among accounting professionals in Malaysia. Based on Nonaka's (1994) knowledge sharing mode, this study found a highly significant relationship between an interactive use of MCS and knowledge sharing to suggest that a more open, less fmancial-oriented and more interactive type of MCS tends to interlink and underpin organizational social process which is the central part of the knowledge sharing process. While professional accountants are generally keen to gain access to knowledge databases to source for possible task solutions, they are generally hesitant to share their tacit knowledge by transforming that knowledge into explicit form. The fmding suggests that there may be cultural-related factors that inhibit sharing of one's tacit knowledge totally and completely.

Improvement on delay dependent absolute stability of Lurie control systems with multiple time delays

Absolute stability of Lurie control systems with multiple time-delays is studied in this paper. By using extended Lyapunov functionals, we avoid the use of the stability assumption on the main operator and derive improved stability criteria, which are strictly less conservative than the criteria in [2,3].

The use of control systems in new product development innovation : advancing the 'help or hinder' debate

New Product Development (NPD) innovation is a critical activity in the current economic environment. In order to manage their NPD innovation projects, firms use Management Controls Systems (MCS). However, the effect that these systems have on NPD innovation is not clear. One stream of research suggests that MCS help NPD innovation while another stream suggests MCS hinder NPD innovation. Past research has shown that the role and style of MCS used may offer explanations on why MCS can both help and hinder NPD innovation. This paper adds another explanation by examining the relationship between three models (divisional, activity/decision and conversion/response) of a commonly used MCS, known as the Stage-Gate Process1 in the NPD innovation literature, and three types of NPD innovation projects (incremental, semi-radical and radical). The insights from an ethnomethodology informed field study are used to understand how and why the firms may use a different MCS (Stage-Gate Process models) for different NPD innovation project types.

Management control systems use, organisational capabilities and performance in universities: application of the resource-based view

Invoking the resource-based view (RBV), this study investigates relationships between management control systems (MCSs) use, including information use from performance measurement systems (PMSs), and organisational capabilities in the context of academic units of Australian universities. Increased competition and attention to distinctive capabilities amongst universities, particularly at their strategic operating unit level of Schools 1, provides the setting for application of this theoretic perspective. The objective of this study is to model various relationships between diagnostic and interactive use of MCSs, attention given to centrally-imposed and discretionary types of PMS information, the strength of capabilities of the academic unit and, in turn, performance of the academic units. This objective is investigated using a field survey in which a mail survey instrument is administered to a census of all Heads of Schools in all 39 universities in Australia. Valid responses were received from 166 Heads. Principal components factor analysis finds that Heads conceived capabilities of their unit in functional dimensions, not in generic dimensions as found in prior literature; Heads also considered performance measures in terms of their importance (critical or discretionary) rather than type (financial versus non-financial). Partial least-squares analysis is then used for path modelling, and several significant results are obtained. Highlights are that diagnostic MCS use and centrally-imposed performance measures, i.e., key performance indicators, but not interactive MCS use or discretionary performance measures, significantly relate to some or all of the strength of capabilities in the fields of teaching, research and networking, and in turn indirectly relate to performance of the academic units. The findings have practical implications for styles of control systems use; focus on selected key performance measures; and development of organisational capabilities for achievement of superior performance by academic schools in universities.

Use of management control systems in university faculties : evidence of diagnostic versus interactive approaches by the upper echelons

Drawing on upper echelon theory and focusing on the context of higher education reforms in Australia within new public management in university faculties/colleges, this study investigates the diagnostic versus interactive uses of management control systems by Deans/Pro-Vice Chancellors of Faculties/Colleges (hereafter called Faculty PVCs). It seeks to identify how the professional and experiential characteristics of these senior academic executives and the structure of their Faculty, impact on their managerial and collegial orientation as reflected in their approach to using management controls. A mail survey of Faculty PVCs is conducted amongst a census of all Faculties/Colleges of all universities in Australia. Supplementing this survey are semi-structured interviews with the PVC of the business and science Faculty at a large Australian university. Results reveal that PVCs who have had a longer career in higher education tend to use MCSs more interactively (or collegially). There is also evidence that as PVCs hold their current position for longer periods, they tend to move from an early diagnostic use of MCSs to a subsequent interactive use. Further, the higher the complexity of a Faculty the more a PVC will adopt an interactive approach to MCS use. Other PVC and Faculty characteristics did not reveal patterns of significant influence on the interactive or diagnostic use of MCSs. A key revelation from interviews is that PVCs will give over-riding importance to meeting centrally-set diagnostically-focused KPI, but still take a collegial approach within their Faculty to the broader use of MCSs. The findings lend limited support to upper echelons theory, but provide a grounding for further research into the impact that a managerial versus a collegial approach by PVCs/Deans may have on their Faculty’s growth in innovative capacities, teaching qualities or financial strength.