997 resultados para Linear Asset
Resumo:
Lifecycle funds offered by retirement plan providers allocate aggressively to risky asset classes when the employee participants are young, gradually switching to more conservative asset classes as they grow older and approach retirement. This approach focuses on maximizing growth of the accumulation fund in the initial years and preserving its value in the later years. The authors simulate terminal wealth outcomes based on conventional lifecycle asset allocation rules as well as on contrarian strategies that reverse the direction of asset switching. The evidence suggests that the growth in portfolio size over time significantly impacts the asset allocation decision. Due to the portfolio size effect that is observed by the authors, the terminal value of accumulation in retirement accounts is influenced more by the asset allocation strategy adopted in later years relative to that adopted in early years. By mechanistically switching to conservative assets in the later years of a plan, lifecycle strategies sacrifice significant growth opportunity and prove counterproductive to the participant's wealth accumulation objective. The authors' conclude that this sacrifice does not seem to be compensated adequately in terms of reducing the risk of potentially adverse outcomes.
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The aim of the study is to identify the opportunities and challenges a local government public asset manager is most likely to deal with when adopting the appropriate Public Asset Management Framework especially in developing countries. In order to achieve its aim, this study employs a Case Study in Indonesia for collecting all data i.e. interviews, document analysis and observations at South Sulawesi Province, Indonesia. The study concludes that there are significant opportunities and challenges that local governments in developing countries, especially Indonesia, might be required to manage if apply public asset management framework appropriately. The opportunities are more effective and efficient local government, accountable and auditable local government organization, increase local government portfolio, reflect up to date information for decision makers in local government, and improve the quality of public services. On the other hand, there are also challenges. Those challenges are local governments has no clear legal and institutional framework to support the asset management application, non-profit principle of public assets, cross jurisdictions and applications in public asset management, the complexity of public organization objectives, and data availability required for managing public property. The study only covers the condition of developing countries where Indonesia as an example, which could not represent exactly the whole local governments’ condition in the world. Further study to develop an asset management system applicable for all local governments in developing countries is urgently needed. Findings from this study will provide useful input for the policy maker, scholars and asset management practitioners to develop an asset management framework for more efficient and effective local governments.
Resumo:
The purpose of this paper is to emphasis the significance of public asset management in Indonesia that is by identifying opportunities and challenges of Indonesian local governments in adopting current practice of Public Asset Management System. A Case Study, in South Sulawesi Provincial government was used as the approach to achieve the research objective. The case study involved two data collection techniques i.e. interviews followed by study on documents. The result of the study indicates there are some significant opportunities and challenges that Indonesian local government might deal with in adopting current practice of public asset management. There are opportunities that can lead to more effective and efficient local government, accountable and auditable local government organization, increase local government portfolio, and improve the quality of public services. The challenges include no clear institutional and legal framework to support the asset management application, non-profit principle of public assets, cross jurisdictions in public asset management, complexity of local government objectives, and unavailability of data for managing public property. The study only covers condition of South Sulawesi Province, which could not represent exactly the whole local governments’ condition in Indonesia. Findings from this study provide useful input for the policy makers, scholars and asset management practitioners in Indonesia to establish a public asset management framework that suitable for Indonesia.
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We explore the empirical usefulness of conditional coskewness to explain the cross-section of equity returns. We find that coskewness is an important determinant of the returns to equity, and that the pricing relationship varies through time. In particular we find that when the conditional market skewness is positive investors are willing to sacrifice 7.87% annually per unit of gamma (a standardized measure of coskewness risk) while they only demand a premium of 1.80% when the market is negatively skewed. A similar picture emerges from the coskewness factor of Harvey and Siddique (Harvey, C., Siddique, A., 2000a. Conditional skewness in asset pricing models tests. Journal of Finance 65, 1263–1295.) (a portfolio that is long stocks with small coskewness with the market and short high coskewness stocks) which earns 5.00% annually when the market is positively skewed but only 2.81% when the market is negatively skewed. The conditional two-moment CAPM and a conditional Fama and French (Fama, E., French, K., 1992. The cross-section of expected returns. Journal of Finance 47,427465.) three-factor model are rejected, but a model which includes coskewness is not rejected by the data. The model also passes a structural break test which many existing asset pricing models fail.
Resumo:
Infrastructure organisations are operating in an increasingly challenging business environment as a result of globalisation, privatisation and deregulation. Under such circumstances, asset managers need to manage their infrastructure assets effectively in order to contribute to the overall performance of their organisation. In an external business environment that is constantly changing, extant literature on strategic management advocates a resourced--�]based view (RBV) approach that focuses on factors internal to the organisation such as resources and capabilities to sustain organisation performance. The aim of this study is to explore the core capabilities needed in the management of infrastructure assets. Using a multiple case study research strategy focusing on transport infrastructure, this research firstly examines the goals of infrastructure asset management and their alignment with broader corporate goals of an infrastructure organisation. It then examines the strategic infrastructure asset management processes that are needed to achieve these goals. The core capabilities that can support the strategic infrastructure asset management processes are then identified. This research produced a number of findings. First, it provided empirical evidence that asset management goals are being pursued with the aim of supporting the broader business goals of infrastructure organisations. Second, through synthesising the key asset management processes deemed necessary to achieve the asset management goals, a strategic infrastructure asset management model is proposed. Third, it identified five core capabilities namely stakeholder connectivity, cross-functional, relational, technology absorptive and integrated information management capability as central to executing the strategic infrastructure asset management processes well. These findings culminate in the development of a capability model to improve the performance of infrastructure assets.
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Purpose - The paper examines the benefits of further diversifying a global portfolio of financial assets with New Zealand farm real estate (FRE). ---------- Design/methodology/approach - We compare efficient sets generated with and without farm real estate using portfolio theory. ---------- Findings - The results show that given the predominantly negative correlation between FRE and financial assets, the risk-return tradeoffs of portfolios of financial assets can be improved significantly. The diversification benefits measured in terms of risk reduction, return enhancement, and improvement in the Sharpe performance ratios are robust under a number of FRE risk-return scenarios as well as under high and low inflationary periods. Using 5- and 10-year rolling periods we also find that FRE is a consistent part of risk efficient portfolios. Consistent with the results reported in Lee and Stevenson (2006) for UK real estate the risk reduction benefits of diversifying with FRE are larger than the risk enhancement benefits. ---------- Practical implication - The results suggest that FRE takes on a consistent role of risk-reducer rather than a return-enhancer in a globally diversified portfolio. FRE appears to deserve more serious consideration by investment practitioners that it has been accorded in the past. Originality/value – The study examines the role of direct real estate in a globally diversified portfolio of financial assets.
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Recently, the numerical modelling and simulation for anomalous subdiffusion equation (ASDE), which is a type of fractional partial differential equation( FPDE) and has been found with widely applications in modern engineering and sciences, are attracting more and more attentions. The current dominant numerical method for modelling ASDE is Finite Difference Method (FDM), which is based on a pre-defined grid leading to inherited issues or shortcomings. This paper aims to develop an implicit meshless approach based on the radial basis functions (RBF) for numerical simulation of the non-linear ASDE. The discrete system of equations is obtained by using the meshless shape functions and the strong-forms. The stability and convergence of this meshless approach are then discussed and theoretically proven. Several numerical examples with different problem domains are used to validate and investigate accuracy and efficiency of the newly developed meshless formulation. The results obtained by the meshless formulations are also compared with those obtained by FDM in terms of their accuracy and efficiency. It is concluded that the present meshless formulation is very effective for the modeling and simulation of the ASDE. Therefore, the meshless technique should have good potential in development of a robust simulation tool for problems in engineering and science which are governed by the various types of fractional differential equations.
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Road agencies require comprehensive, relevan and quality data describing their road assets to support their investment decisions. An investment decision support system for raod maintenance and rehabilitation mainly comprise three important supporting elements namely: road asset data, decision support tools and criteria for decision-making. Probability-based methods have played a crucial role in helping decision makers understand the relationship among road related data, asset performance and uncertainties in estimating budgets/costs for road management investment. This paper presents applications of the probability-bsed method for road asset management.
Resumo:
Purpose – The purpose of this paper is to develop a conceptual framework that can be used to identify capabilities needed in the management of infrastructure assets. Design/methodology/approach – This paper utilises a qualitative approach to analyse secondary data in order to develop a conceptual framework that identifies capabilities for strategic infrastructure asset management. Findings – In an external business environment that is undergoing rapid change, it is more appropriate to focus on factors internal to the organisation such as resources and capabilities as a basis to develop competitive advantage. However, there is currently very little understanding of the internal capabilities that are appropriate for infrastructure asset management. Therefore, a conceptual framework is needful to guide infrastructure organisations in the identification of capabilities. Research limitations/implications – This is a conceptual paper and future empirical research should be conducted to validate the propositions made in the paper. Practical implications – The paper clearly argues the need for infrastructure organisations to adopt a systematic approach to identifying the capabilities needed in the management of strategic infrastructure assets. The discussion on the impact of essential capabilities is useful in providing the impetus for managers who operate in a deregulated infrastructure business landscape to review their existing strategies. Originality/value – The paper provides a new perspective on how asset managers can create value for their organisations by investing in the relevant capabilities.
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This thesis is devoted to the study of linear relationships in symmetric block ciphers. A block cipher is designed so that the ciphertext is produced as a nonlinear function of the plaintext and secret master key. However, linear relationships within the cipher can still exist if the texts and components of the cipher are manipulated in a number of ways, as shown in this thesis. There are four main contributions of this thesis. The first contribution is the extension of the applicability of integral attacks from word-based to bitbased block ciphers. Integral attacks exploit the linear relationship between texts at intermediate stages of encryption. This relationship can be used to recover subkey bits in a key recovery attack. In principle, integral attacks can be applied to bit-based block ciphers. However, specific tools to define the attack on these ciphers are not available. This problem is addressed in this thesis by introducing a refined set of notations to describe the attack. The bit patternbased integral attack is successfully demonstrated on reduced-round variants of the block ciphers Noekeon, Present and Serpent. The second contribution is the discovery of a very small system of equations that describe the LEX-AES stream cipher. LEX-AES is based heavily on the 128-bit-key (16-byte) Advanced Encryption Standard (AES) block cipher. In one instance, the system contains 21 equations and 17 unknown bytes. This is very close to the upper limit for an exhaustive key search, which is 16 bytes. One only needs to acquire 36 bytes of keystream to generate the equations. Therefore, the security of this cipher depends on the difficulty of solving this small system of equations. The third contribution is the proposal of an alternative method to measure diffusion in the linear transformation of Substitution-Permutation-Network (SPN) block ciphers. Currently, the branch number is widely used for this purpose. It is useful for estimating the possible success of differential and linear attacks on a particular SPN cipher. However, the measure does not give information on the number of input bits that are left unchanged by the transformation when producing the output bits. The new measure introduced in this thesis is intended to complement the current branch number technique. The measure is based on fixed points and simple linear relationships between the input and output words of the linear transformation. The measure represents the average fraction of input words to a linear diffusion transformation that are not effectively changed by the transformation. This measure is applied to the block ciphers AES, ARIA, Serpent and Present. It is shown that except for Serpent, the linear transformations used in the block ciphers examined do not behave as expected for a random linear transformation. The fourth contribution is the identification of linear paths in the nonlinear round function of the SMS4 block cipher. The SMS4 block cipher is used as a standard in the Chinese Wireless LAN Wired Authentication and Privacy Infrastructure (WAPI) and hence, the round function should exhibit a high level of nonlinearity. However, the findings in this thesis on the existence of linear relationships show that this is not the case. It is shown that in some exceptional cases, the first four rounds of SMS4 are effectively linear. In these cases, the effective number of rounds for SMS4 is reduced by four, from 32 to 28. The findings raise questions about the security provided by SMS4, and might provide clues on the existence of a flaw in the design of the cipher.
Resumo:
An Asset Management (AM) life-cycle constitutes a set of processes that align with the development, operation and maintenance of assets, in order to meet the desired requirements and objectives of the stake holders of the business. The scope of AM is often broad within an organization due to the interactions between its internal elements such as human resources, finance, technology, engineering operation, information technology and management, as well as external elements such as governance and environment. Due to the complexity of the AM processes, it has been proposed that in order to optimize asset management activities, process modelling initiatives should be adopted. Although organisations adopt AM principles and carry out AM initiatives, most do not document or model their AM processes, let alone enacting their processes (semi-) automatically using a computer-supported system. There is currently a lack of knowledge describing how to model AM processes through a methodical and suitable manner so that the processes are streamlines and optimized and are ready for deployment in a computerised way. This research aims to overcome this deficiency by developing an approach that will aid organisations in constructing AM process models quickly and systematically whilst using the most appropriate techniques, such as workflow technology. Currently, there is a wealth of information within the individual domains of AM and workflow. Both fields are gaining significant popularity in many industries thus fuelling the need for research in exploring the possible benefits of their cross-disciplinary applications. This research is thus inspired to investigate these two domains to exploit the application of workflow to modelling and execution of AM processes. Specifically, it will investigate appropriate methodologies in applying workflow techniques to AM frameworks. One of the benefits of applying workflow models to AM processes is to adapt and enable both ad-hoc and evolutionary changes over time. In addition, this can automate an AM process as well as to support the coordination and collaboration of people that are involved in carrying out the process. A workflow management system (WFMS) can be used to support the design and enactment (i.e. execution) of processes and cope with changes that occur to the process during the enactment. So far few literatures can be found in documenting a systematic approach to modelling the characteristics of AM processes. In order to obtain a workflow model for AM processes commonalities and differences between different AM processes need to be identified. This is the fundamental step in developing a conscientious workflow model for AM processes. Therefore, the first stage of this research focuses on identifying the characteristics of AM processes, especially AM decision making processes. The second stage is to review a number of contemporary workflow techniques and choose a suitable technique for application to AM decision making processes. The third stage is to develop an intermediate ameliorated AM decision process definition that improves the current process description and is ready for modelling using the workflow language selected in the previous stage. All these lead to the fourth stage where a workflow model for an AM decision making process is developed. The process model is then deployed (semi-) automatically in a state-of-the-art WFMS demonstrating the benefits of applying workflow technology to the domain of AM. Given that the information in the AM decision making process is captured at an abstract level within the scope of this work, the deployed process model can be used as an executable guideline for carrying out an AM decision process in practice. Moreover, it can be used as a vanilla system that, once being incorporated with rich information from a specific AM decision making process (e.g. in the case of a building construction or a power plant maintenance), is able to support the automation of such a process in a more elaborated way.