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This review presents various control strategies for application systems utilizing smart magneto-rheological fluid (MRF) and magneto-rheological elastomers (MRE). It is well known that both MRF and MRE are actively studied and applied to many practical systems such as vehicle dampers. The mandatory requirements for successful applications of MRF and MRE include several factors: advanced material properties, optimal mechanisms, suitable modeling, and appropriate control schemes. Among these requirements, the use of an appropriate control scheme is a crucial factor since it is the final action stage of the application systems to achieve the desired output responses. There are numerous different control strategies which have been applied to many different application systems of MRF and MRE, summarized in this review. In the literature review, advantages and disadvantages of each control scheme are discussed so that potential researchers can develop more effective strategies to achieve higher control performance of many application systems utilizing magneto-rheological materials.

This review presents various control strategies for application systems utilizing smart magneto-rheological fluid (MRF) and magneto-rheological elastomers (MRE). It is well known that both MRF and MRE are actively studied and applied to many practical systems such as vehicle dampers. The mandatory requirements for successful applications of MRF and MRE include several factors: advanced material properties, optimal mechanisms, suitable modeling, and appropriate control schemes. Among these requirements, the use of an appropriate control scheme is a crucial factor since it is the final action stage of the application systems to achieve the desired output responses. There are numerous different control strategies which have been applied to many different application systems of MRF and MRE, summarized in this review. In the literature review, advantages and disadvantages of each control scheme are discussed so that potential researchers can develop more effective strategies to achieve higher control performance of many application systems utilizing magneto-rheological materials.

This review presents various control strategies for application systems utilizing smart magneto-rheological fluid (MRF) and magneto-rheological elastomers (MRE). It is well known that both MRF and MRE are actively studied and applied to many practical systems such as vehicle dampers. The mandatory requirements for successful applications of MRF and MRE include several factors: advanced material properties, optimal mechanisms, suitable modeling, and appropriate control schemes. Among these requirements, the use of an appropriate control scheme is a crucial factor since it is the final action stage of the application systems to achieve the desired output responses. There are numerous different control strategies which have been applied to many different application systems of MRF and MRE, summarized in this review. In the literature review, advantages and disadvantages of each control scheme are discussed so that potential researchers can develop more effective strategies to achieve higher control performance of many application systems utilizing magneto-rheological materials.

This review presents various control strategies for application systems utilizing smart magneto-rheological fluid (MRF) and magneto-rheological elastomers (MRE). It is well known that both MRF and MRE are actively studied and applied to many practical systems such as vehicle dampers. The mandatory requirements for successful applications of MRF and MRE include several factors: advanced material properties, optimal mechanisms, suitable modeling, and appropriate control schemes. Among these requirements, the use of an appropriate control scheme is a crucial factor since it is the final action stage of the application systems to achieve the desired output responses. There are numerous different control strategies which have been applied to many different application systems of MRF and MRE, summarized in this review. In the literature review, advantages and disadvantages of each control scheme are discussed so that potential researchers can develop more effective strategies to achieve higher control performance of many application systems utilizing magneto-rheological materials.

Purpose Employee suggestion scheme (ESS) have existed for many years and many articles have been published over the past decades. They have been studied from many perspectives to illustrate their objectives, nature, content, process, significance and the benefits. Arguments have also been made with respect to success and failures of the suggestion schemes. Although the corporations widely use the suggestion schemes to elicit the creative ideas of their employees, sustaining a suggestion scheme is still a challenge. The purpose of this paper is to extract the critical success factors and critical success criteria to the suggestion scheme and to discuss the importance of these factors on sustainability of suggestion system. This is a literature review paper. Design/methodology/approach This is a literature review paper. The research used the university library to search for the relevant material. The university has an access for 25,000 journals. As the university had the subscription to main databases such as EBASCO, SCIENCE DIRECT, EMERALD, Google Scholar and WILEY, a search was performed on these databases using the key terms. The keywords used in the searches included: Suggestion System, Suggestion Scheme, Employee Participation, Employee Involvement, Innovation, Employee Creativity and Ideas Management. The Google Scholar citation tab was also searched further to identify any related articles. The citations of resulting articles were scrutinized further for further clues. Findings This paper identifies 23 critical success factors and 9 critical success criteria for suggestion schemes. It also discusses the interconnection between the critical success factors and the critical success criteria. Further, the frequency of each of the factors is also presented. It recognizes the lack of work on the assessment framework for sustainability of a suggestion scheme. Practical implications This paper should be of value to practitioners of suggestion schemes and to academics

Purpose Employee suggestion scheme (ESS) have existed for many years and many articles have been published over the past decades. They have been studied from many perspectives to illustrate their objectives, nature, content, process, significance and the benefits. Arguments have also been made with respect to success and failures of the suggestion schemes. Although the corporations widely use the suggestion schemes to elicit the creative ideas of their employees, sustaining a suggestion scheme is still a challenge. The purpose of this paper is to extract the critical success factors and critical success criteria to the suggestion scheme and to discuss the importance of these factors on sustainability of suggestion system. This is a literature review paper. Design/methodology/approach This is a literature review paper. The research used the university library to search for the relevant material. The university has an access for 25,000 journals. As the university had the subscription to main databases such as EBASCO, SCIENCE DIRECT, EMERALD, Google Scholar and WILEY, a search was performed on these databases using the key terms. The keywords used in the searches included: Suggestion System, Suggestion Scheme, Employee Participation, Employee Involvement, Innovation, Employee Creativity and Ideas Management. The Google Scholar citation tab was also searched further to identify any related articles. The citations of resulting articles were scrutinized further for further clues. Findings This paper identifies 23 critical success factors and 9 critical success criteria for suggestion schemes. It also discusses the interconnection between the critical success factors and the critical success criteria. Further, the frequency of each of the factors is also presented. It recognizes the lack of work on the assessment framework for sustainability of a suggestion scheme. Practical implications This paper should be of value to practitioners of suggestion schemes and to academics

Purpose - The purpose of this paper is to propose a sustainability assessment model and to discuss the implications for organizational learning. Paper presents a sustainability excellence model comprising of three stages and discuss the good practices for sustaining the employee suggestion scheme. Design/methodology/approach - The assessment framework was developed drawing on a thorough review of the literature and data collected and analyzed using various statistical tools. The developed assessment framework was validated through a case of an organization based in the United Arab Emirates. Semi-structured interviews were used to elicit relevant information during the case study. Findings - An assessment framework comprising five major factors for sustainability of suggestion scheme of has been presented. The five factors include: leadership and work environment, system capability, system effectiveness, organizational encouragement and system barriers. Sustainability of a suggestion system can be understood as a three-stage model comprising the initial stage, the developmental stage and the advanced stage. The key practices associated for each of these stages are discussed in detail. Practical implications - The framework has taken into consideration the critical success factors and critical success factors emerged from the literature review conducted for this study. Therefore, the framework could be further refined by conducting more case studies and can propose maturity levels. Originality/value - The paper has developed a framework that can be used to assess the sustainability of the suggestion scheme in an organization. This model has been applied to assess the individual schemes and draw upon potential change strategies.

Purpose – The purpose of this paper is to assess the employee suggestion scheme of three organizations based in the United Arab Emirates. A framework that consists of five sustainability factors identified based on an empirical study has been applied. The sustainability factors identified through this study include leadership and organizational environment, system capability, system effectiveness, organizational encouragement and system barrier. The paper draws conclusions about the key practices necessary to foster sustainability of the employee suggestion system. The paper then presents a final framework that the organizations can apply to assess their suggestion schemes and to develop potential change strategies. The study findings reveal the importance of five factors, and with more cases, future research can be conducted to identify further practices relevant to specific industry. More levels of maturity for sustainability suggestion system could also be defined with future research. Design/methodology/approach – The assessment framework was developed drawing on a thorough review of the literature and data collected and analyzed using various statistical tools. The developed assessment framework was validated using case study method. Semi-structured interviews were used to elicit relevant information during the case study. Findings – An assessment framework comprising five major factors for sustainability of suggestion scheme of has been presented. The five factors include: leadership and work environment, system capability, system effectiveness, organizational encouragement and system barriers. Sustainability of a suggestion system can be understood as a three-stage model comprising three stages: the initial stage, the developmental stage and the advanced stage. The key practices associated for each of these stages are discussed in detail. Research limitations/implications – The framework has taken into consideration the critical success factors, and critical

Purpose – The purpose of this paper is to assess the employee suggestion scheme of three organizations based in the United Arab Emirates. A framework that consists of five sustainability factors identified based on an empirical study has been applied. The sustainability factors identified through this study include leadership and organizational environment, system capability, system effectiveness, organizational encouragement and system barrier. The paper draws conclusions about the key practices necessary to foster sustainability of the employee suggestion system. The paper then presents a final framework that the organizations can apply to assess their suggestion schemes and to develop potential change strategies. The study findings reveal the importance of five factors, and with more cases, future research can be conducted to identify further practices relevant to specific industry. More levels of maturity for sustainability suggestion system could also be defined with future research. Design/methodology/approach – The assessment framework was developed drawing on a thorough review of the literature and data collected and analyzed using various statistical tools. The developed assessment framework was validated using case study method. Semi-structured interviews were used to elicit relevant information during the case study. Findings – An assessment framework comprising five major factors for sustainability of suggestion scheme of has been presented. The five factors include: leadership and work environment, system capability, system effectiveness, organizational encouragement and system barriers. Sustainability of a suggestion system can be understood as a three-stage model comprising three stages: the initial stage, the developmental stage and the advanced stage. The key practices associated for each of these stages are discussed in detail. Research limitations/implications – The framework has taken into consideration the critical success factors, and critical

Purpose – The purpose of this paper is to assess the employee suggestion scheme of three organizations based in the United Arab Emirates. A framework that consists of five sustainability factors identified based on an empirical study has been applied. The sustainability factors identified through this study include leadership and organizational environment, system capability, system effectiveness, organizational encouragement and system barrier. The paper draws conclusions about the key practices necessary to foster sustainability of the employee suggestion system. The paper then presents a final framework that the organizations can apply to assess their suggestion schemes and to develop potential change strategies. The study findings reveal the importance of five factors, and with more cases, future research can be conducted to identify further practices relevant to specific industry. More levels of maturity for sustainability suggestion system could also be defined with future research. Design/methodology/approach – The assessment framework was developed drawing on a thorough review of the literature and data collected and analyzed using various statistical tools. The developed assessment framework was validated using case study method. Semi-structured interviews were used to elicit relevant information during the case study. Findings – An assessment framework comprising five major factors for sustainability of suggestion scheme of has been presented. The five factors include: leadership and work environment, system capability, system effectiveness, organizational encouragement and system barriers. Sustainability of a suggestion system can be understood as a three-stage model comprising three stages: the initial stage, the developmental stage and the advanced stage. The key practices associated for each of these stages are discussed in detail. Research limitations/implications – The framework has taken into consideration the critical success factors, and critical

Purpose – The purpose of this paper is to assess the employee suggestion scheme of three organizations based in the United Arab Emirates. A framework that consists of five sustainability factors identified based on an empirical study has been applied. The sustainability factors identified through this study include leadership and organizational environment, system capability, system effectiveness, organizational encouragement and system barrier. The paper draws conclusions about the key practices necessary to foster sustainability of the employee suggestion system. The paper then presents a final framework that the organizations can apply to assess their suggestion schemes and to develop potential change strategies. The study findings reveal the importance of five factors, and with more cases, future research can be conducted to identify further practices relevant to specific industry. More levels of maturity for sustainability suggestion system could also be defined with future research. Design/methodology/approach – The assessment framework was developed drawing on a thorough review of the literature and data collected and analyzed using various statistical tools. The developed assessment framework was validated using case study method. Semi-structured interviews were used to elicit relevant information during the case study. Findings – An assessment framework comprising five major factors for sustainability of suggestion scheme of has been presented. The five factors include: leadership and work environment, system capability, system effectiveness, organizational encouragement and system barriers. Sustainability of a suggestion system can be understood as a three-stage model comprising three stages: the initial stage, the developmental stage and the advanced stage. The key practices associated for each of these stages are discussed in detail. Research limitations/implications – The framework has taken into consideration the critical success factors, and critical

A ring signature scheme provides signer ambiguity by hiding a signer in a ring of arbitrary members appropriately. A convertible ring signature scheme is an extension of a ring signature scheme that authenticates a signer and proves that a real signer and no one else generated a ring signature. In this paper, we first show that the recent convertible ring signature scheme proposed by Jeong et al. [16] is vulnerable to collusion attacks. Second, we present a formal security model for a convertible ring signature with collusion resistance. The security notion of a convertible ring signature is intrinsically different from that of an ordinary ring signature due to the conversion property. For our collusion resistance, we consider full key exposure, that is, even an adversary who knows all secret keys will not be able to break the collusion resistance. Finally, we construct a novel convertible ring signature scheme with collusion resistance and prove the security of the scheme in the presented security model. We also compare our scheme with the existing ring signature schemes in the literature to show its advantages.

A ring signature scheme provides signer ambiguity by hiding a signer in a ring of arbitrary members appropriately. A convertible ring signature scheme is an extension of a ring signature scheme that authenticates a signer and proves that a real signer and no one else generated a ring signature. In this paper, we first show that the recent convertible ring signature scheme proposed by Jeong et al. [16] is vulnerable to collusion attacks. Second, we present a formal security model for a convertible ring signature with collusion resistance. The security notion of a convertible ring signature is intrinsically different from that of an ordinary ring signature due to the conversion property. For our collusion resistance, we consider full key exposure, that is, even an adversary who knows all secret keys will not be able to break the collusion resistance. Finally, we construct a novel convertible ring signature scheme with collusion resistance and prove the security of the scheme in the presented security model. We also compare our scheme with the existing ring signature schemes in the literature to show its advantages.

The purpose of this paper is to assess the sustainability of employee suggestion scheme of three organizations based in the United Arab Emirates. A framework has been used to assess the sustainability of the suggestion schemes. Based on the analysis of the three cases, five factors to assess the sustainability of employee suggestion scheme and the three stages of sustainability are discussed. The paper presents three cases and draws conclusions about the key practices necessary to foster sustainability of employee suggestion system. Through the case studies, several issues related to the sustainability of the suggestion scheme have been identified. The paper then presents a final framework that the organizations can apply to assess their suggestion schemes and to develop potential change strategies. The study findings reveal the importance of five factors and with more cases; future research can be reveal more practices. These could be further examined in relation to specific industry.

This paper presents an effective procedure for solving the job shop problem. Synergistically combining small and large neighborhood schemes, the procedure consists of four components, namely (i) a construction method for generating semi-active schedules by a forward-backward mechanism, (ii) a local search for manipulating a small neighborhood structure guided by a tabu list, (iii) a feedback-based mechanism for perturbing the solutions generated, and (iv) a very large-neighborhood local search guided by a forward-backward shifting bottleneck method. The combination of shifting bottleneck mechanism and tabu list is used as a means of the manipulation of neighborhood structures, and the perturbation mechanism employed diversifies the search. A feedback mechanism, called cycle-check, detects consequent repeats as cycles and ignites the perturbation when the total number of consecutive repeats for two identical makespan values reaches a given threshold. The results of extensive computational experiments on the benchmark instances indicate that the combination of these four components is synergetic, in the sense that they collectively make the procedure fast and robust.

This paper presents an effective procedure for solving the job shop problem. Synergistically combining small and large neighborhood schemes, the procedure consists of four components, namely (i) a construction method for generating semi-active schedules by a forward-backward mechanism, (ii) a local search for manipulating a small neighborhood structure guided by a tabu list, (iii) a feedback-based mechanism for perturbing the solutions generated, and (iv) a very large-neighborhood local search guided by a forward-backward shifting bottleneck method. The combination of shifting bottleneck mechanism and tabu list is used as a means of the manipulation of neighborhood structures, and the perturbation mechanism employed diversifies the search. A feedback mechanism, called cycle-check, detects consequent repeats as cycles and ignites the perturbation when the total number of consecutive repeats for two identical makespan values reaches a given threshold. The results of extensive computational experiments on the benchmark instances indicate that the combination of these four components is synergetic, in the sense that they collectively make the procedure fast and robust.

This paper presents an effective procedure for solving the job shop problem. Synergistically combining small and large neighborhood schemes, the procedure consists of four components, namely (i) a construction method for generating semi-active schedules by a forward-backward mechanism, (ii) a local search for manipulating a small neighborhood structure guided by a tabu list, (iii) a feedback-based mechanism for perturbing the solutions generated, and (iv) a very large-neighborhood local search guided by a forward-backward shifting bottleneck method. The combination of shifting bottleneck mechanism and tabu list is used as a means of the manipulation of neighborhood structures, and the perturbation mechanism employed diversifies the search. A feedback mechanism, called cycle-check, detects consequent repeats as cycles and ignites the perturbation when the total number of consecutive repeats for two identical makespan values reaches a given threshold. The results of extensive computational experiments on the benchmark instances indicate that the combination of these four components is synergetic, in the sense that they collectively make the procedure fast and robust.

This paper presents an effective procedure for solving the job shop problem. Synergistically combining small and large neighborhood schemes, the procedure consists of four components, namely (i) a construction method for generating semi-active schedules by a forward-backward mechanism, (ii) a local search for manipulating a small neighborhood structure guided by a tabu list, (iii) a feedback-based mechanism for perturbing the solutions generated, and (iv) a very large-neighborhood local search guided by a forward-backward shifting bottleneck method. The combination of shifting bottleneck mechanism and tabu list is used as a means of the manipulation of neighborhood structures, and the perturbation mechanism employed diversifies the search. A feedback mechanism, called cycle-check, detects consequent repeats as cycles and ignites the perturbation when the total number of consecutive repeats for two identical makespan values reaches a given threshold. The results of extensive computational experiments on the benchmark instances indicate that the combination of these four components is synergetic, in the sense that they collectively make the procedure fast and robust.

Secure distributed data storage can shift the burden of maintaining a large number of files from the owner to proxy servers. Proxy servers can convert encrypted files for the owner to encrypted files for the receiver without the necessity of knowing the content of the original files. In practice, the original files will be removed by the owner for the sake of space efficiency. Hence, the issues on confidentiality and integrity of the outsourced data must be addressed carefully. In this paper, we propose two identity-based secure distributed data storage (IBSDDS) schemes. Our schemes can capture the following properties: (1) The file owner can decide the access permission independently without the help of the private key generator (PKG); (2) For one query, a receiver can only access one file, instead of all files of the owner; (3) Our schemes are secure against the collusion attacks. Although the first scheme is only secure against the chosen plaintext attacks (CPA), the second scheme is secure against the chosen ciphertext attacks (CCA). To the best of our knowledge, it is the first IBSDDS schemes where an access permissions is made by the owner for an exact file and collusion attacks can be protected in the standard model.

There is evidence that easily accessible, comprehensible and consistent nutrient information on the front of packaged foods could assist shoppers to make healthier food choices. This study used an online questionnaire of 4357 grocery shoppers to examine Australian shoppers' ability to use a range of front-of-pack labels to identify healthier food products. Seven different front-of-pack labelling schemes comprising variants of the Traffic Light labelling scheme and the Percentage Daily Intake scheme, and a star rating scheme, were applied to nine pairs of commonly purchased food products. Participants could also access a nutrition information panel for each product. Participants were able to identify the healthier product in each comparison over 80% of the time using any of the five schemes that provided information on multiple nutrients. No individual scheme performed significantly better in terms of shoppers' ability to determine the healthier product, shopper reliance on the 'back-of-pack' nutrition information panel, and speed of use. The scheme that provided information about energy only and a scheme with limited numerical information of nutrient type or content performed poorly, as did the nutrition information panel alone (control). Further consumer testing is necessary to determine the optimal format and content of an interpretive front-of-pack nutrition labelling scheme.

There is evidence that easily accessible, comprehensible and consistent nutrient information on the front of packaged foods could assist shoppers to make healthier food choices. This study used an online questionnaire of 4357 grocery shoppers to examine Australian shoppers' ability to use a range of front-of-pack labels to identify healthier food products. Seven different front-of-pack labelling schemes comprising variants of the Traffic Light labelling scheme and the Percentage Daily Intake scheme, and a star rating scheme, were applied to nine pairs of commonly purchased food products. Participants could also access a nutrition information panel for each product. Participants were able to identify the healthier product in each comparison over 80% of the time using any of the five schemes that provided information on multiple nutrients. No individual scheme performed significantly better in terms of shoppers' ability to determine the healthier product, shopper reliance on the 'back-of-pack' nutrition information panel, and speed of use. The scheme that provided information about energy only and a scheme with limited numerical information of nutrient type or content performed poorly, as did the nutrition information panel alone (control). Further consumer testing is necessary to determine the optimal format and content of an interpretive front-of-pack nutrition labelling scheme.

Developments in fisheries governance in recent decades—notably the1982 United Nations Convention on the Law of the Sea and its implementing agreements—have established a framework o fprinciples, standards, institutions and regulations that is broade rand more complex than traditional fisheries management, which has generally focused o nindividual target species. As this framework has evolved, a number of seafood eco-labelling schemes have also developed. These schemes aim to identify well- managed fisheries and give competitive advantage to their products, thus translating the environmental awareness of consumers into direct support for sustainable fishing practices.This paper evaluates a number of these schemes in the context of international fisheries governance principles and considers the conservation benefits that may result from sustainability certification of Pacific tuna fisheries. The paper briefly summarises developments in eco-labeling of Pacific tuna fisheries in relation to the evolution of fisheries management, where focus has shifted from the maximum sustainable yield of individual tuna species to ecosystem-based approaches that directly consider the broader environmental impacts of fishing. The paper discusses two different ‘Dolphin Safe’ eco-labels, the third-party scheme of the Earth Island Institute and the intergovernmental scheme of the Agreement on the International Dolphin Conservation Program, and two broader eco-labels offering sustainability certification of fisheries, ‘Friend of the Sea’ and the ‘Marine Stewardship Council’. The role played by seafood-industry associations with sustainability claims, such as the International Seafood Sustainability Foundation, is also considered.

Purpose: Governmental agencies are interested in improving the quality of their service delivery. One tool that has been used to manage their performance is performance based reward schemes (PBRS). The aim of this paper is to examine the degree to which a sample of these plans, used within the Botswana public sector, is customer-focused. Being more customer-focused should deliver improved public sector service quality. Design/methodology/approach: This study carried out an evaluation of a sample of Botswana PBRS plans, using multidimensional content analysis undertaken by four expert "evaluators", to identify the degree to which the PBRS were customer-focused. Findings: Classifying PBRS plans as being customer-focused was difficult, as the plans had few objectives related to customer experiences or outcomes. Those that did had poorly defined performance objectives, their targets were not specific, or there was limited explicit role responsibility. Thus, PBRS plans seemed not to focus on improving customer outcomes. Research limitations/implications: The PBRS evaluated do not appear to be customer-focused and, thus, would have limited ability to improve customer experiences (i.e. public sector quality). Further research is needed in other countries to see whether these results are generalisable, and whether service levels vary with more customer-focused PBRS plans. Practical implications: The results suggest improvements that could be adopted by organisations seeking to make their PBRS schemes customer-focused. Originality/value: Extensive research suggests that PBRS plans can be used to improve service quality. Most of the studies have focused on the employees' perspectives and have not looked at the degree of customer orientation within the plans. Emerald Group Publishing Limited.

Four novel nanographene/porphyrin hybrids were prepared, characterized, and probed in solar energy conversion schemes. Exfoliation of graphite by means of immobilizing four different porphyrins onto the basal plane of graphene is accompanied by distinct electronic interactions in both the ground and the excited states. In the ground state, a strong loss in oscillator strength goes hand-in-hand with a notable broadening of the porphyrin transitions and, as such, attests to the shift of electron density from the electron donating porphyrins to nanographene. In the excited state, a nearly quantitative quenching of the porphyrin fluorescence is indicative of full charge transfer. The latter is corroborated by femtosecond transient absorption measurements, which reveal the generation of the one-electron oxidized radical cation of the porphyrins with absorption maxima at 490 and 625 nm in the visible region and conduction band electrons in nanographene with features at 890 and 1025 nm in the near infrared region. We have demonstrated the applicability of the new nanographene/porphyrin hybrids in, for example, solar cells. In this regard, the presence of flakes is crucial in terms of influencing the injection processes, preventing aggregation, and reducing recombination losses, which are commonly encountered in porphyrin-based DSSCs. 2013 The Royal Society of Chemistry.

Across various jurisdictions, crime statistics indicate the rate of youth offending, particularly violent offending, has increased over the last decade. Anecdotal evidence further suggests the nature of youth offending has changed over this time-frame; including an increase in more serious criminal behaviour as well as changes in both the demographic and psychological profiles of youth offenders. This is particularly evident in accounts depicting an increasing tendency amongst some young people to engage in acts of 'appetitive' violence. This is a form of violence purportedly perpetrated by youth in an excitable and predatory state, which differs from the more common forms of reactive and instrumental violence. Although newsprint media reports suggest that appetitive violence is alarmingly common, there is currently no corroborating empirical evidence. This paper explores the classification of violence by youth utilising three contemporary classification systems. One hundred and forty-three case files from the Children's Court Clinic in Victoria, Australia, were examined, comparing all youth (aged 10-19) convicted of a violent offence referred to the Clinic for psychological assessment in the years 2000 and 2010. Results indicated a similarly low prevalence of appetitive violence (2000-15.8%; 2010-8.6%). Further, they indicated the quadripartite and tripartite classification systems increased the discrimination of aggressive behaviours beyond that provided by the traditional reactive/instrumental dichotomy.

Single Sign-on (SSO) allows a user to obtain a single credential from a Trusted Third Party (TTP) once and then authenticates himself/herself to different service providers by using the same credential. Though different SSO schemes have been obtained from various primitives, user anonymity has not yet been studied formally. Motivated by the fact that anonymity is a very essential security requirement in certain scenarios, in this paper we first formalize a security model of anonymous single-sign on (ASSO). Subsequently, we present a generic ASSO scheme which is transformed from group signatures. Formal proofs are provided to show that the proposed ASSO is secure under the assumption that the underlying group signature is secure according to Bell are et al.'s model introduced at CT-RSA 2005. Compared to existing SSO schemes, our transformation not only implements the user's anonymity, but also reduces the trust level in TTP.

Single Sign-on (SSO) allows users to only log on once and then access different services via automatic authentication by using the same credential. However, most existing SSO schemes do not satisfy security notions or require a high trust level on a trusted third party (TTP), even though SSO has become popular in new distributed systems and computer networks. Motivated by this fact, we formalise a new security model of single sign-on, which not only satisfies strong security notions but also has a low trust level on TTP. We then propose a generic construction of SSO from nominative signatures, and present concrete initialisation. We also provide formal proofs to show that the proposed SSO scheme is secure according to our new formal model, if the underlying nominative signature is secure. We note that this is the first study that investigates the link between SSO and nominative signatures, which also be of an independent interest.

Four novel nanographene/porphyrin hybrids were prepared, characterized, and probed in solar energy conversion schemes. Exfoliation of graphite by means of immobilizing four different porphyrins onto the basal plane of graphene is accompanied by distinct electronic interactions in both the ground and the excited states. In the ground state, a strong loss in oscillator strength goes hand-in-hand with a notable broadening of the porphyrin transitions and, as such, attests to the shift of electron density from the electron donating porphyrins to nanographene. In the excited state, a nearly quantitative quenching of the porphyrin fluorescence is indicative of full charge transfer. The latter is corroborated by femtosecond transient absorption measurements, which reveal the generation of the one-electron oxidized radical cation of the porphyrins with absorption maxima at 490 and 625 nm in the visible region and conduction band electrons in nanographene with features at 890 and 1025 nm in the near infrared region. We have demonstrated the applicability of the new nanographene/porphyrin hybrids in, for example, solar cells. In this regard, the presence of flakes is crucial in terms of influencing the injection processes, preventing aggregation, and reducing recombination losses, which are commonly encountered in porphyrin-based DSSCs. 2013 The Royal Society of Chemistry.

Innovations are becoming increasingly important for organizations to remain competitive in the dynamic business environment. Employee Suggestions Systems (ESS) is a useful tool used in the organization to elicit employees' creative ideas. Over the past decades, suggestion schemes have been studied from many perspectives. The objective of this paper is to present the history and evolution of suggestion schemes, from their early beginnings to sophisticated computer based systems that are widely popular in many countries. It begins with the discussion of origins of suggestion systems, followed by discussing how they have evolved over the years, and understands a typical process involved in suggestion system. The future model is discussed that can sustain and contribute significantly towards the success of the organizations. Through a literature review, it's described the existing research on suggestion schemes to understand the critical drivers and barriers for the success of the suggestion schemes. This paper also cites and illustrates the well-known suggestion systems used by UAE organizations and their benefits. This paper should be of value to practitioners of suggestion schemes and to academicians who are interested in knowing how this program has evolved, and where it is today and what future it holds. This paper has assimilated the existing knowledge on suggestion systems to provide a quick run through to the field and has extended the search for drivers and barriers to suggestion scheme from creativity and innovation literature.

This paper presents two Identity-Based Blind Signature (IBBS) schemes based on bilinear pairings. Both of them enjoy the following features. First, they achieve the optimal bound of round complexity for blind signatures, i.e., each signature can be blindly generated with one round (or two moves) of message exchanges between the signature requesting user and signer. Second, their security is proved without the ROS assumption, which assumes that it is infeasible to find an overdetermined, solvable system of linear equations modulo q with random inhomogenities. Due to this reason, the order of underlying group does not need to be very large any more, as compared to the previous work. Third, the key extraction algorithm used is the most popular one in ID-based cryptography. In fact, the proposed two constructions are first IBBS schemes enjoying all the above advantages. Different from other IBBS schemes, these two IBBS schemes are constructed from scratch in the sense that new ID-based signature schemes are customized and new assumptions (e.g., two versions of one-more bilinear Diffie- Hellman inversion assumption) are formalized.We also show that the new ID-based schemes and new assumptions may have other interesting applications.

This paper presents two Identity-Based Blind Signature (IBBS) schemes based on bilinear pairings. Both of them enjoy the following features. First, they achieve the optimal bound of round complexity for blind signatures, i.e., each signature can be blindly generated with one round (or two moves) of message exchanges between the signature requesting user and signer. Second, their security is proved without the ROS assumption, which assumes that it is infeasible to find an overdetermined, solvable system of linear equations modulo q with random inhomogenities. Due to this reason, the order of underlying group does not need to be very large any more, as compared to the previous work. Third, the key extraction algorithm used is the most popular one in ID-based cryptography. In fact, the proposed two constructions are first IBBS schemes enjoying all the above advantages. Different from other IBBS schemes, these two IBBS schemes are constructed from scratch in the sense that new ID-based signature schemes are customized and new assumptions (e.g., two versions of one-more bilinear Diffie- Hellman inversion assumption) are formalized.We also show that the new ID-based schemes and new assumptions may have other interesting applications.

This paper presents two Identity-Based Blind Signature (IBBS) schemes based on bilinear pairings. Both of them enjoy the following features. First, they achieve the optimal bound of round complexity for blind signatures, i.e., each signature can be blindly generated with one round (or two moves) of message exchanges between the signature requesting user and signer. Second, their security is proved without the ROS assumption, which assumes that it is infeasible to find an overdetermined, solvable system of linear equations modulo q with random inhomogenities. Due to this reason, the order of underlying group does not need to be very large any more, as compared to the previous work. Third, the key extraction algorithm used is the most popular one in ID-based cryptography. In fact, the proposed two constructions are first IBBS schemes enjoying all the above advantages. Different from other IBBS schemes, these two IBBS schemes are constructed from scratch in the sense that new ID-based signature schemes are customized and new assumptions (e.g., two versions of one-more bilinear Diffie- Hellman inversion assumption) are formalized.We also show that the new ID-based schemes and new assumptions may have other interesting applications.

This report explores the experiences and aspirations of youth in Wadeye, a remote Aboriginal community in the Northern Territory which has become synonymous with the deviant behaviours of its young people. The research was undertaken over a three year period, and builds upon a previous ten year period of community based research. As such it forms a unique longitudinal study of young people during a period of extreme change in their lives. The research applied a mixed methods approach, utilising ethnography, interviews and the application of a community wide survey. Although young community based people were the primary focus of the study, the research also included the wider community perspectives, service provide rs and a sample of imprisoned community members. The proliferation of gangs in the Wadeye community has become a primary focus for outsiders' interpretation of social issues in the community. These gangs have been defined by their violent and oppositional cultures. This period of research and the research which preceded it, emphasise the complexity of gang cultures and gang dynamics in this community. The report also emphasises that a primary focus on gangs serves to obscure other factors influencing young people's lives and behaviours. This includes those youth who do not engage in deviant behaviour, who attend school and progress to employment. It also includes youth who engage in non-gang related violent and anti-social behaviour. The report argues that effective service delivery and the development of appropriate diversion activities for young people must recognise the diversity and complexity of the youth experience in the community and recognise and develop their current strengths. Feedback from elders, young people and long-term community workers, advocates that more partnership approaches to further research and program evaluation must become an integral part of the process. Involving young people themselves as part of this research process will pr

Oblivious signature-based envelope (OSBE) schemes have demonstrated their potential applications in the protection of users privacy and rights. In an OSBE protocol, an encrypted message can only be decrypted by the receiver who holds a valid signature on a public message, while the sender (encrypter) does not know whether the receiver has the signature or not. Our major contributions in this work lie in the following aspects. We improve the notion of OSBE so that a valid credential holder cannot share his/her credential with other users (i. e., all-or-nothing non-transferability). We clarify the relationship between one-round OSBE and identity-based encryption (IBE) and show that one-round OSBE and semantically secure IBE against the adaptively chosen identity attack (IND-ID-CPA) are equivalent, if the signature in the OSBE scheme is existentially unforgeable against adaptively chosen message attacks. We propose an oblivious access control scheme to protect user privacy without the aid of any zero-knowledge proof. Finally, we also highlight some other novel applications of OSBE, such as attributed-based encryption. 2012 Springer-Verlag.

This report explores the experiences and aspirations of youth in Wadeye, a remote Aboriginal community in the Northern Territory which has become synonymous with the deviant behaviours of its young people. The research was undertaken over a three year period, and builds upon a previous ten year period of community based research. As such it forms a unique longitudinal study of young people during a period of extreme change in their lives. The research applied a mixed methods approach, utilising ethnography, interviews and the application of a community wide survey. Although young community based people were the primary focus of the study, the research also included the wider community perspectives, service provide rs and a sample of imprisoned community members. The proliferation of gangs in the Wadeye community has become a primary focus for outsiders' interpretation of social issues in the community. These gangs have been defined by their violent and oppositional cultures. This period of research and the research which preceded it, emphasise the complexity of gang cultures and gang dynamics in this community. The report also emphasises that a primary focus on gangs serves to obscure other factors influencing young people's lives and behaviours. This includes those youth who do not engage in deviant behaviour, who attend school and progress to employment. It also includes youth who engage in non-gang related violent and anti-social behaviour. The report argues that effective service delivery and the development of appropriate diversion activities for young people must recognise the diversity and complexity of the youth experience in the community and recognise and develop their current strengths. Feedback from elders, young people and long-term community workers, advocates that more partnership approaches to further research and program evaluation must become an integral part of the process. Involving young people themselves as part of this research process will pr

This paper presents two Identity-Based Blind Signature (IBBS) schemes based on bilinear pairings. Both of them enjoy the following features. First, they achieve the optimal bound of round complexity for blind signatures, i.e., each signature can be blindly generated with one round (or two moves) of message exchanges between the signature requesting user and signer. Second, their security is proved without the ROS assumption, which assumes that it is infeasible to find an overdetermined, solvable system of linear equations modulo q with random inhomogenities. Due to this reason, the order of underlying group does not need to be very large any more, as compared to the previous work. Third, the key extraction algorithm used is the most popular one in ID-based cryptography. In fact, the proposed two constructions are first IBBS schemes enjoying all the above advantages. Different from other IBBS schemes, these two IBBS schemes are constructed from scratch in the sense that new ID-based signature schemes are customized and new assumptions (e.g., two versions of one-more bilinear Diffie- Hellman inversion assumption) are formalized.We also show that the new ID-based schemes and new assumptions may have other interesting applications.

Carbon dioxide emission inequalities between and within five income groups of countries are computed. The revealed dominant inequality between the high income groups and the low and middle income groups and its likely intensification by an internationally uniform abatement rate constitute a case for using per capita figures in assessing countries' unilateral and internationally cooperative abatements. Our analysis suggests that the cooperative expected net benefit maximizing abatement can be smaller than the unilateral abatement for weak countries and for countries with high ability and inclination to politically and economically reward other countries.

The certificateless encryption (CLE) scheme proposed by Baek, Safavi-Naini and Susilo is computation-friendly since it does not require any pairing operation. Unfortunately, an error was later discovered in their security proof and so far the provable security of the scheme remains unknown. Recently, Fiore, Gennaro and Smart showed a generic way (referred to as the FGS transformation) to transform identity-based key agreement protocols to certificateless key encapsulation mechanisms (CL-KEMs). As a typical example, they showed that the pairing-free CL-KEM underlying Baek et al.'s CLE can be ''generated'' by applying their transformation to the Fiore-Gennaro (FG) identity-based key agreement (IB-KA) protocol. In this paper, we show that directly applying the Fiore-Gennaro-Smart (FGS) transformation to the original FG IB-KA protocol in fact results in an insecure CL-KEM scheme against strong adversaries, we also give a way to fix the problem without adding any computational cost. The reason behind our attack is that the FGS transformation requires the underlying IB-KA protocol to be secure in a model that is stronger than the conventional security models where existing IB-KA protocols are proved secure, and the FG IB-KA protocol is in fact insecure in the new model. This motivates us to construct a new generic transformation from IB-KA protocols to CLE schemes. In the paperwepresent such a transformation which only requires the underlying IB-KA protocol to be secure in a security model that is weaker than the existing security models for IB-KA protocols. We illustrate our transformation by generating a new pairing-free CLE scheme that is obtained by directly applying our transformation to the original FG IB-KA protocol. 2010

Carbon dioxide emission inequalities between and within five income groups of countries are computed. The revealed dominant inequality between the high income groups and the low and middle income groups and its likely intensification by an internationally uniform abatement rate constitute a case for using per capita figures in assessing countries' unilateral and internationally cooperative abatements. Our analysis suggests that the cooperative expected net benefit maximizing abatement can be smaller than the unilateral abatement for weak countries and for countries with high ability and inclination to politically and economically reward other countries.

The certificateless encryption (CLE) scheme proposed by Baek, Safavi-Naini and Susilo is computation-friendly since it does not require any pairing operation. Unfortunately, an error was later discovered in their security proof and so far the provable security of the scheme remains unknown. Recently, Fiore, Gennaro and Smart showed a generic way (referred to as the FGS transformation) to transform identity-based key agreement protocols to certificateless key encapsulation mechanisms (CL-KEMs). As a typical example, they showed that the pairing-free CL-KEM underlying Baek et al.'s CLE can be ''generated'' by applying their transformation to the Fiore-Gennaro (FG) identity-based key agreement (IB-KA) protocol. In this paper, we show that directly applying the Fiore-Gennaro-Smart (FGS) transformation to the original FG IB-KA protocol in fact results in an insecure CL-KEM scheme against strong adversaries, we also give a way to fix the problem without adding any computational cost. The reason behind our attack is that the FGS transformation requires the underlying IB-KA protocol to be secure in a model that is stronger than the conventional security models where existing IB-KA protocols are proved secure, and the FG IB-KA protocol is in fact insecure in the new model. This motivates us to construct a new generic transformation from IB-KA protocols to CLE schemes. In the paperwepresent such a transformation which only requires the underlying IB-KA protocol to be secure in a security model that is weaker than the existing security models for IB-KA protocols. We illustrate our transformation by generating a new pairing-free CLE scheme that is obtained by directly applying our transformation to the original FG IB-KA protocol. 2010

The certificateless encryption (CLE) scheme proposed by Baek, Safavi-Naini and Susilo is computation-friendly since it does not require any pairing operation. Unfortunately, an error was later discovered in their security proof and so far the provable security of the scheme remains unknown. Recently, Fiore, Gennaro and Smart showed a generic way (referred to as the FGS transformation) to transform identity-based key agreement protocols to certificateless key encapsulation mechanisms (CL-KEMs). As a typical example, they showed that the pairing-free CL-KEM underlying Baek et al.'s CLE can be ''generated'' by applying their transformation to the Fiore-Gennaro (FG) identity-based key agreement (IB-KA) protocol. In this paper, we show that directly applying the Fiore-Gennaro-Smart (FGS) transformation to the original FG IB-KA protocol in fact results in an insecure CL-KEM scheme against strong adversaries, we also give a way to fix the problem without adding any computational cost. The reason behind our attack is that the FGS transformation requires the underlying IB-KA protocol to be secure in a model that is stronger than the conventional security models where existing IB-KA protocols are proved secure, and the FG IB-KA protocol is in fact insecure in the new model. This motivates us to construct a new generic transformation from IB-KA protocols to CLE schemes. In the paperwepresent such a transformation which only requires the underlying IB-KA protocol to be secure in a security model that is weaker than the existing security models for IB-KA protocols. We illustrate our transformation by generating a new pairing-free CLE scheme that is obtained by directly applying our transformation to the original FG IB-KA protocol. 2010

The certificateless encryption (CLE) scheme proposed by Baek, Safavi-Naini and Susilo is computation-friendly since it does not require any pairing operation. Unfortunately, an error was later discovered in their security proof and so far the provable security of the scheme remains unknown. Recently, Fiore, Gennaro and Smart showed a generic way (referred to as the FGS transformation) to transform identity-based key agreement protocols to certificateless key encapsulation mechanisms (CL-KEMs). As a typical example, they showed that the pairing-free CL-KEM underlying Baek et al.'s CLE can be ''generated'' by applying their transformation to the Fiore-Gennaro (FG) identity-based key agreement (IB-KA) protocol. In this paper, we show that directly applying the Fiore-Gennaro-Smart (FGS) transformation to the original FG IB-KA protocol in fact results in an insecure CL-KEM scheme against strong adversaries, we also give a way to fix the problem without adding any computational cost. The reason behind our attack is that the FGS transformation requires the underlying IB-KA protocol to be secure in a model that is stronger than the conventional security models where existing IB-KA protocols are proved secure, and the FG IB-KA protocol is in fact insecure in the new model. This motivates us to construct a new generic transformation from IB-KA protocols to CLE schemes. In the paperwepresent such a transformation which only requires the underlying IB-KA protocol to be secure in a security model that is weaker than the existing security models for IB-KA protocols. We illustrate our transformation by generating a new pairing-free CLE scheme that is obtained by directly applying our transformation to the original FG IB-KA protocol. 2010

Carbon dioxide emission inequalities between and within five income groups of countries are computed. The revealed dominant inequality between the high income groups and the low and middle income groups and its likely intensification by an internationally uniform abatement rate constitute a case for using per capita figures in assessing countries' unilateral and internationally cooperative abatements. Our analysis suggests that the cooperative expected net benefit maximizing abatement can be smaller than the unilateral abatement for weak countries and for countries with high ability and inclination to politically and economically reward other countries.

Purpose: Iterative projection reconstruction algorithms are currently the preferred reconstruction method in proton computed tomography (pCT). However, due to inconsistencies in the measured data arising from proton energy straggling and multiple Coulomb scattering, the noise in the reconstructed image increases with successive iterations. In the current work, the authors investigated the use of total variation superiorization (TVS) schemes that can be applied as an algorithmic add-on to perturbation-resilient iterative projection algorithms for pCT image reconstruction. Methods: The block-iterative diagonally relaxed orthogonal projections (DROP) algorithm was used for reconstructing GEANT4 Monte Carlo simulated pCT data sets. Two TVS schemes added on to DROP were investigated; the first carried out the superiorization steps once per cycle and the second once per block. Simplifications of these schemes, involving the elimination of the computationally expensive feasibility proximity checking step of the TVS framework, were also investigated. The modulation transfer function and contrast discrimination function were used to quantify spatial and density resolution, respectively. Results: With both TVS schemes, superior spatial and density resolution was achieved compared to the standard DROP algorithm. Eliminating the feasibility proximity check improved the image quality, in particular image noise, in the once-per-block superiorization, while also halving image reconstruction time. Overall, the greatest image quality was observed when carrying out the superiorization once per block and eliminating the feasibility proximity check. Conclusions: The low-contrast imaging made possible with TVS holds a promise for its incorporation into future pCT studies.

Purpose: Iterative projection reconstruction algorithms are currently the preferred reconstruction method in proton computed tomography (pCT). However, due to inconsistencies in the measured data arising from proton energy straggling and multiple Coulomb scattering, the noise in the reconstructed image increases with successive iterations. In the current work, the authors investigated the use of total variation superiorization (TVS) schemes that can be applied as an algorithmic add-on to perturbation-resilient iterative projection algorithms for pCT image reconstruction. Methods: The block-iterative diagonally relaxed orthogonal projections (DROP) algorithm was used for reconstructing GEANT4 Monte Carlo simulated pCT data sets. Two TVS schemes added on to DROP were investigated; the first carried out the superiorization steps once per cycle and the second once per block. Simplifications of these schemes, involving the elimination of the computationally expensive feasibility proximity checking step of the TVS framework, were also investigated. The modulation transfer function and contrast discrimination function were used to quantify spatial and density resolution, respectively. Results: With both TVS schemes, superior spatial and density resolution was achieved compared to the standard DROP algorithm. Eliminating the feasibility proximity check improved the image quality, in particular image noise, in the once-per-block superiorization, while also halving image reconstruction time. Overall, the greatest image quality was observed when carrying out the superiorization once per block and eliminating the feasibility proximity check. Conclusions: The low-contrast imaging made possible with TVS holds a promise for its incorporation into future pCT studies.

Purpose: Iterative projection reconstruction algorithms are currently the preferred reconstruction method in proton computed tomography (pCT). However, due to inconsistencies in the measured data arising from proton energy straggling and multiple Coulomb scattering, the noise in the reconstructed image increases with successive iterations. In the current work, the authors investigated the use of total variation superiorization (TVS) schemes that can be applied as an algorithmic add-on to perturbation-resilient iterative projection algorithms for pCT image reconstruction. Methods: The block-iterative diagonally relaxed orthogonal projections (DROP) algorithm was used for reconstructing GEANT4 Monte Carlo simulated pCT data sets. Two TVS schemes added on to DROP were investigated; the first carried out the superiorization steps once per cycle and the second once per block. Simplifications of these schemes, involving the elimination of the computationally expensive feasibility proximity checking step of the TVS framework, were also investigated. The modulation transfer function and contrast discrimination function were used to quantify spatial and density resolution, respectively. Results: With both TVS schemes, superior spatial and density resolution was achieved compared to the standard DROP algorithm. Eliminating the feasibility proximity check improved the image quality, in particular image noise, in the once-per-block superiorization, while also halving image reconstruction time. Overall, the greatest image quality was observed when carrying out the superiorization once per block and eliminating the feasibility proximity check. Conclusions: The low-contrast imaging made possible with TVS holds a promise for its incorporation into future pCT studies.

Purpose: Iterative projection reconstruction algorithms are currently the preferred reconstruction method in proton computed tomography (pCT). However, due to inconsistencies in the measured data arising from proton energy straggling and multiple Coulomb scattering, the noise in the reconstructed image increases with successive iterations. In the current work, the authors investigated the use of total variation superiorization (TVS) schemes that can be applied as an algorithmic add-on to perturbation-resilient iterative projection algorithms for pCT image reconstruction. Methods: The block-iterative diagonally relaxed orthogonal projections (DROP) algorithm was used for reconstructing GEANT4 Monte Carlo simulated pCT data sets. Two TVS schemes added on to DROP were investigated; the first carried out the superiorization steps once per cycle and the second once per block. Simplifications of these schemes, involving the elimination of the computationally expensive feasibility proximity checking step of the TVS framework, were also investigated. The modulation transfer function and contrast discrimination function were used to quantify spatial and density resolution, respectively. Results: With both TVS schemes, superior spatial and density resolution was achieved compared to the standard DROP algorithm. Eliminating the feasibility proximity check improved the image quality, in particular image noise, in the once-per-block superiorization, while also halving image reconstruction time. Overall, the greatest image quality was observed when carrying out the superiorization once per block and eliminating the feasibility proximity check. Conclusions: The low-contrast imaging made possible with TVS holds a promise for its incorporation into future pCT studies.

Recently, several ID-based key sharing schemes have been proposed, where an initiation phase generates users' secret key associated with identities under the hardness of integer factorization. In this letter, we show that, unfortunately any key sharing scheme with this initiation phase is intrinsically insecure in the sense that the collusion of some users enables them to derive master private keys and hence, generating any user's secret key.

Cooperative communication has been intensively considered for general wireless and sensor networks. However, it has been almost untouched in Space-Time-Frequency Coded Multi-band OFDM Ultra-Wideband (STFC MB-OFDM UWB) systems. This paper thus proposes two cross-layer designs for cooperative communication, namely Simple Cooperative Communication Scheme (SCCS) and Advanced Cooperative Communication Scheme (ACCS), in slow fading scenarios. In the former, nodes always cooperate with one another despite the possibly erroneous reception at the partner nodes, while in the latter, nodes cooperate only in the case of successful reception. Simulations show that these schemes may considerably improve the performance of STFC MB-OFDM UWB without any increase of transmission power.

In this paper, we investigate single-carrier (SC) and multi-carrier IDMA schemes with cyclic prefixing (CP) and zero padding (ZP) techniques. These schemes are called SC-IDMA-CP, SC-IDMA-ZP, orthogonal frequency-division multiplexing (OFDM)-IDMA-CP and OFDM-IDMA-ZP, respectively. By exploiting the circulant property of channel matrices, the multi-user detection of these schemes can be efficiently realised with per-user complexity independent of the number of users and the length of inter-symbol interference (ISI) channels. We show the potential advantages of ZP-based schemes in power efficiency and convergence speed. Simulation results are provided to compare the four schemes. Copyright © 2008 John Wiley & Sons, Ltd.