Key predistribution scheme using finite fields and reed muller codes

Resource constraint sensors of a Wireless Sensor Network (WSN) cannot afford the use of costly encryption techniques like public key while dealing with sensitive data. So symmetric key encryption techniques are preferred where it is essential to have the same cryptographic key between communicating parties. To this end, keys are preloaded into the nodes before deployment and are to be established once they get deployed in the target area. This entire process is called key predistribution. In this paper we propose one such scheme using unique factorization of polynomials over Finite Fields. To the best of our knowledge such an elegant use of Algebra is being done for the first time in WSN literature. The best part of the scheme is large number of node support with very small and uniform key ring per node. However the resiliency is not good. For this reason we use a special technique based on Reed Muller codes proposed recently by Sarkar, Saha and Chowdhury in 2010. The combined scheme has good resiliency with huge node support using very less keys per node.

Achieving simple, secure and efficient hierarchical access control in cloud computing

Access control is an indispensable security component of cloud computing, and hierarchical access control is of particular interest since in practice one is entitled to different access privileges. This paper presents a hierarchical key assignment scheme based on linear-geometry as the solution of flexible and fine-grained hierarchical access control in cloud computing. In our scheme, the encryption key of each class in the hierarchy is associated with a private vector and a public vector, and the inner product of the private vector of an ancestor class and the public vector of its descendant class can be used to derive the encryption key of that descendant class. The proposed scheme belongs to direct access schemes on hierarchical access control, namely each class at a higher level in the hierarchy can directly derive the encryption key of its descendant class without the need of iterative computation. In addition to this basic hierarchical key derivation, we also give a dynamic key management mechanism to efficiently address potential changes in the hierarchy. Our scheme only needs light computations over finite field and provides strong key indistinguishability under the assumption of pseudorandom functions. Furthermore, the simulation shows that our scheme has an optimized trade-off between computation consumption and storage space.

A finite element simulation of micro-mechanical frictional behaviour in metal forming

Friction is a critical factor for sheet metal forming (SMF). The Coulomb friction model is usually used in most finite element (FE) simulation for SMF. However, friction is a function of the local contact deformation conditions, such as local pressure, roughness and relative velocity. Frictional behaviour between contact surfaces can be based on three cases: boundary, hydrodynamic and mixed lubrication. In our microscopic friction model based on the finite element method (FEM), the case of dry contact between sheet and tool has been considered. In the view of microscopic geometry, roughness depends upon amplitude and wavelength of surface asperities of sheet and tool. The mean pressure applied on the surface differs from the pressure over the actual contact area. The effect of roughness (microscopic geometric condition) and relative speed of contact surfaces on friction coefficient was examined in the FE model for the microscopic friction behaviour. The analysis was performed using an explicit FE formulation. In this study, it was found that the roughness of deformable sheet decreases during sliding and the coefficient of friction increases with increasing roughness of contact surfaces. Also, the coefficient of friction increases with the increase of relative velocity and adhesive friction coefficient between contact surfaces.

Algebraic attacks over GF(q)

Recent algebraic attacks on LFSR-based stream ciphers and S-boxes have generated much interest as they appear to be extremely powerful. Theoretical work has been developed focusing around the Boo- lean function case. In this paper, we generalize this theory to arbitrary finite fields and extend the theory of annihilators and ideals introduced at Eurocrypt 2004 by Meier, Pasalic and Carlet. In particular, we prove that for any function f in the multivariate polynomial ring over GF(q), f has a low degree multiple precisely when two low degree functions appear in the same coset of the annihilator of f ^{q – 1} – 1. In this case, many such low degree multiples exist.

Codes of ethics in corporate Sweden

Purpose – The purpose of the study is to examine and describe the use of codes of ethics in the top 100 companies operating in the Swedish corporate sector. This paper reports on the responses of those companies that possessed a code of ethics.

Design/methodology/approach – A three-stage research procedure was used. First, a questionnaire was sent to the public relations managers of the top 100 companies operating in the Swedish corporate sector (based on revenue). Companies were asked to answer up to 29 questions and to supply a copy of their code of ethics. The second stage involved content analysis of the codes of ethics supplied by survey respondents. The third stage involved a more detailed follow-up of a smaller group of firms that appeared to be close to best practice. Findings for Stage 1 of the research are reported in this paper. The areas of questioning were: how common are codes of ethics? Who was involved in the development of these codes? What are the reasons for the codes? How are they implemented? Do companies inform internal and external publics of the codes? What are the prescribed benefits of the codes?

Findings – It would appear that business ethics has only recently become a topic of interest in corporate Sweden and that many companies are in the early stages of code development and assimilation into company policies. The incidence of codes in the population (of 100) suggested by this survey (56 per cent) is lower than a US study finding (in 1995) that over 84 per cent of comparable US companies had codes of ethics. It would appear that Sweden today lags behind the US situation of 1995. When one investigates the special measures to support the inculcation of ethical values at the organizational level, there appears to be some shortfall. The supporting measures of ethics committees, ethics training committees, ethics training, ombudsman, an ethical audit and procedures to protect whistleblowers appear to be under-utilized in companies that possess codes. This lack of utilization tends to suggest that companies in Sweden, as yet, either have not developed a high commitment to supporting business ethics in their corporations, or they may have developed other methods to support their codes in their organizations that they view are as beneficial as the traditional methods practised in other western industrial democracies.

Research limitations/implications – This research was limited to internal ethical expectations. The commitment to business ethics is usually explored in terms of internal ethical expectations, but the simultaneous consideration of the external ethical expectations in the marketplace (e.g. among suppliers and customers or other publics) is desirable. A dyadic approach considering a company's internal ethical expectations and the external ethical expectations of a company's business activities may give a more balanced and in-depth approach.

Practical implications – Evidence is now available to show that codes of ethics are well developed in many of Sweden's largest corporations: organizations that, from their responses, appear to see a diverse range of benefits in developing the area of business ethics. Companies are beginning to implement not only a code of ethics, but other complementary initiatives that reinforce the need for the culture of the organization to be ethical. Codes of ethics are perceived by organizations to have assisted them in their dealings in the marketplace and many companies use their ethical values to underpin their strategic planning process. It appears that many companies now see the formalisation of business ethics as an integral part of their commercial practices.

Originality/value – This study is the first one of its kind on codes of ethics in corporate Sweden. It will enable all sectors of Swedish business to benchmark their efforts against the major companies in the Swedish corporate sector.

Statistical analysis of finite element modeling in sheet metal forming and springback analysis

This work focuses on development of a method to statistically study forming and springback problems of TRansformation Induced Plasticity (TRIP) through an industrial case study. A Design of Experiments (DOE) approach was used to study the sensitivity of predictions to four user input parameters in implicit and explicit sheet metal forming codes. Numerical results were compared to experimental measurements of parts stamped in an industrial production line. The accuracy of forming strain predictions for TRIP steel were comparable with conventional steel, but the springback predictions of TRIP steel were far less accurate. The statistical importance of selected parameters for forming and springback prediction is also discussed. Changes of up to ±10% in Young's modulus and coefficient of friction were found to be insignificant in improving or deteriorating the statistical correlation of springback accuracies.

A question of continuing control -balancing building quality of housing and building codes

The Building Code of Australia seeks to establish “nationally consistent, minimum necessary standards of relevant, health, safety (including structural safety and safety from fire), amenity and sustainability objectives efficiently”. These goals are laudable – but where are the goals of quality and maintenance, which are also an essential part of achieving adequate and continuing health and safety for the built environment?

Defects such as dampness, settlement and cracking, staining, wood rot, termite damage, rusting, and roof leakage are common enough to suggest that there are still issues with building quality in housing. They are caused by a combination of initial poor workmanship and poor quality materials and latterly by poorly executed or inadequate maintenance.

Local architecture, developed over many years of trial and error, produce buildings linked to their climate and local materials (think of the typical “Queenslander” house). Today’s architecture imports technologies and materials from many differing countries and climates – that are not necessarily suitable for the location, nor is there necessarily the same quality control over the material quality and production. Inappropriate use and inadequate understanding of new materials and techniques can lead to the generation of further defects.

Whilst the building code contains provisions for initial-build material quality and workmanship, there is no continuing control over a house over its life span. Reliance is placed on advertising the need, for example, to employ qualified tradespeople; replace batteries in smoke detectors; and other good advice to help maintain housing to a minimum standard. Is this sufficient?

Mechanisms to make the transfer of knowledge to those who need to use it – be it the workforce or the houseowner – need to be improved. Should the building code be more visual and accessible in it’s content? Should the building code include provisions for maintenance? Should the building code require every house to have a “users manual” – much like a car? An extensive review of literature identifies the scale of the problem of poor quality housing and highlights some suggested causes – inadequate knowledge of the BCA by general housebuilders being one. However little work has been done to investigate what could be done to improve the situation. This work suggests that improvements to knowledge transfer would improve the quality of housing and a model of the knowledge transfer process is proposed, identifying those areas where the knowledge flows need to occur that would impact both the builders and users of housing.

Communicating the ethos of corporate codes of ethics in the UK and the USA

Business ethics has been a consideration for corporations in the USA since at least the early 1960s, whilst in the UK this interest in business ethics appears to be just over 20 years old. In a survey of the top 500 companies operating in the private sector in the UK and the USA, it would appear that corporations operating in the UK have embraced the ethos of codes of ethics differently to their USA counterparts and that this difference may well be in line with their different adoption rates over the last 50 years of the need for business ethics in organizations. The USA seems to lead the UK in most areas, except when it comes to ethical audits and incorporating the ethics code into the strategic planning process. Could this omission in respect to strategic planning be the Achilles Heel of US business?

Multilabel classification using error correction codes

This paper presents a multilabel classification method that employs an error correction code together with a base ensemble learner to deal with multilabel data. It explores two different error correction codes: convolutional code and BCH code. A random forest learner is used as its based learner. The performance of the proposed method is evaluated experimentally. The popular multilabel yeast dataset is used for benchmarking. The results are compared against those of several exiting approaches. The proposed method performs well against its counterparts.

Finite element analysis of plastic deformation in variable lead axisymmetric forward spiral extrusion

A modified axisymmetric forward spiral extrusion (AFSE) has been proposed recently to enhance the strain accumulation during the process. The new technique is called variable lead axisymmetric forward spiral extrusion (VLAFSE) that features a variable lead along the extrusion direction. To assess the effect of design modification on plastic deformation, a comprehensive study has been performed here using a 3D transient finite element (FE) model. The FE results established the shear deformation as the dominant mode of deformation which has been confirmed experimentally. The variable lead die extends strain accumulation in the radial and longitudinal directions over the entire grooved section of the die and eliminates the rigid body rotation which occurs in the case of a constant lead die, AFSE. A comparison of forming loads for VLAFSE and AFSE proved the advantages of the former design in the reduction of the forming load which is more pronounced under higher frictional coefficients. This finding proves that the efficiency of VLAFSE is higher than that of AFSE. Besides, the significant amount of accumulated shear strain in VLAFSE along with non-axisymmetric distribution of friction creates a surface feature in the processed sample called zipper effect that has been investigated. © 2012 Springer Science+Business Media New York.

Exploring in-hospital adverse drug events using ICD-10 codes

 Abstract
Objective Adverse drug events (ADEs) during hospital admissions are a widespread problem associated with adverse patient outcomes. The ‘external cause’ codes in the International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10) provide opportunities for identifying the incidence of ADEs acquired during hospital stays that may assist in targeting interventions to decrease their occurrence. The aim of the present study was to use routine administrative data to identify ADEs acquired during hospital admissions in a suburban healthcare network in Melbourne, Australia.

Methods Thirty-nine secondary diagnosis fields of hospital discharge data for a 1-year period were reviewed for ‘diagnoses not present on admission’ and assigned to the Classification of Hospital Acquired Diagnoses (CHADx) subclasses. Discharges with one or more ADE subclass were extracted for retrospective analysis.

Results From 57 205 hospital discharges, 7891 discharges (13.8%) had at least one CHADx, and 402 discharges (0.7%) had an ADE recorded. The highest proportion of ADEs was due to administration of analgesics (27%) and systemic antibiotics (23%). Other major contributors were anticoagulation (13%), anaesthesia (9%) and medications with cardiovascular side-effects (9%).

Conclusion Hospital data coded in ICD-10 can be used to identify ADEs that occur during hospital stays and also clinical conditions, therapeutic drug classes and treating units where these occur. Using the CHADx algorithm on administrative datasets provides a consistent and economical method for such ADE monitoring.

What is known about the topic? Adverse drug events (ADEs) can result in several different physical consequences, ranging from allergic reactions to death, thereby posing a significant burden on patients and the health system. Numerous studies have compared manual, written incident reporting systems used by hospital staff with computerised automated systems to identify ADEs acquired during hospital admissions. Despite various approaches aimed at improving the detection of ADEs, they remain under-reported, as a result of which interventions to mitigate the effect of ADEs cannot be initiated effectively.

What does this paper add? This research article demonstrates major methodological advances over comparable published studies looking at the effectiveness of using routine administrative data to monitor rates of ADEs that occur during a hospital stay and reviews the type of ADEs and their frequency patterns during patient admission. It also provides an insight into the effect of ADEs that occur within different hospital treating units. The method implemented in this study is unique because it uses a grouping algorithm developed for the Australian Commission on Safety and Quality in Health Care (ACSQHC) to identify ADEs not present on admission from patient data coded in ICD-10. This algorithm links the coded external causes of ADEs with their consequences or manifestations. ADEs identified through the use of programmed code based on this algorithm have not been studied in the past and therefore this paper adds to previous knowledge in this subject area.

What are the implications for health professionals? Although not all ADEs can be prevented with current medical knowledge, this study can assist health professionals in targeting interventions that can efficiently reduce the rate of ADEs that occur during a hospital stay, and improve information available for future medication management decisions.

Finite element model updating using estimation of distribution algorithm

Finite Element (FE) model updating has been attracting research attentions in structural engineering fields for over 20 years. Its immense importance to the design, construction and maintenance of civil and mechanical structures has been highly recognised. However, many sources of uncertainties may affect the updating results. These uncertainties may be caused by FE modelling errors, measurement noises, signal processing techniques, and so on. Therefore, research efforts on model updating have been focusing on tackling with uncertainties for a long time. Recently, a new type of evolutionary algorithms has been developed to address uncertainty problems, known as Estimation of Distribution Algorithms (EDAs). EDAs are evolutionary algorithms based on estimation and sampling from probabilistic models and able to overcome some of the drawbacks exhibited by traditional genetic algorithms (GAs). In this paper, a numerical steel simple beam is constructed in commercial software ANSYS. The various damage scenarios are simulated and EDAs are employed to identify damages via FE model updating process. The results show that the performances of EDAs for model updating are efficient and reliable.

A study of guided wave propagation in timber pole using spectral finite element method

Timber is one of the most widely used structural material all over the world. Round timbers can be seen as a structural component in historical buildings, jetties, short span bridges and also as piles for foundation and poles for electrical and power distribution. To evaluate the current condition of these cylindrical type timber structures, guided wave has a great potential. However, the difficulties associated with the guided wave propagation in timber materials includes orthotropic behaviour of wood, moisture contents, temperature, grain direction, etc. In addition, the effect of fully or partially filled surrounding media, such as soil, water, etc. causes attenuation on the generated stress wave. In order to investigate the effects of these parameters on guided wave propagation, extensive numerical simulation is required to conduct parametric studies. Moreover, due to the presence of multi modes in guided wave propagation, dispersion curves are of great importance. Even though conventional finite element method (FEM) can determine dispersion curves along with wave propagation in time domain, it is highly computationally expensive. Furthermore, incorporating orthotropic behaviour and surrounding media to model a thick cylindrical wave (large diameter cylindrical structures) make conventional FEM inefficient for this purpose. In contrast, spectral finite element method (SFEM) is a semi analytical method to model the guided wave propagation which does not need fine meshes compared to the other methods, such as FEM or finite difference method (FDM). Also, even distribution of mass and stiffness of structures can be obtained with very few elements using SFEM. In this paper, the suitability of SFEM is investigated to model guided wave propagation through an orthotropic cylindrical waveguide with the presence of surrounding soil. Both the frequency domain analysis (dispersion curves) and time domain reconstruction for a multi-mode generated input signal are presented under different loading location. The dispersion curves obtained from SFEM are compared against analytical solution to verify its accuracy. Lastly, different numerical issues to solve for the dispersion curves and time domain results using SFEM are also discussed.

Migration intermediaries and codes of conduct: temporary migrant workers in Australian horticulture

Over recent decades, developments in network governance have seen governments around the world cede considerable authority and responsibility to commercial migration intermediaries for recruiting and managing temporary migrant labour. Correspondingly, a by-product of network governance has been the emergence of soft employment regulation in which voluntary codes of conduct supplement hard (enforceable) legal employment standards. This paper explores these developments in the context of temporary migrant workers employed in Australian horticulture. First the paper analyses the growing use of temporary migrant labour in this industry. It then describes how different types of intermediaries interact with this workforce. The paper then outlines both hard and soft employment regulations, and contrasts them with actual employment conditions, questioning how a network governance approach has affected this vulnerable workforce. The paper concludes that changes in network governance of migration and employment relations have emasculated formal legal regulation, leaving market forces to operate without effective or ethical constraints at the expense of the public good.