Integrating socio-economic and biophysical data to support water allocations within river basins: An example from the Inkomati Water Management Area in South Africa

Sustainable natural resource management requires inputs from both the natural and the social sciences. Since natural and social systems are inter-related and inter-dependent, it is essential that these data can be integrated within a given analysis, which requires that they are spatially compatible. However, existing environmental and socio-economic monitoring networks tend to observe, collect and report socio-economic and biophysical data separately; with the result that much of these data are spatially incompatible, adding to the complexity of objective and consistent resource management. We present an approach for overcoming spatial incompatibilities between socio-economic and biophysical data; based on a meta-modelling approach using Geographical Information Systems and an application of a water-use simulation model. The method is developed and applied to the irrigation agriculture sector in the Inkomati Water Management Area in South Africa. Agricultural census data, which are measured on a magisterial district scale, are integrated with geo-referenced land-cover data, which are independent of political boundaries. This allows us to increase the resolution at which data on the economic value derived from irrigation water are presented, from coarse magisterial district scale to a finer ‘meso-zone’ scale, enabling more efficient allocations of irrigation water within magisterial districts.     

Operations Research and public policy for Africa: harnessing the revolution in management science instruction

Operations Research (OR) has made major contributions in the developed world to public policy domains that are of great relevance to Africa. Inasmuch as OR has failed to live up to its potential for addressing such issues in Africa, a principal barrier may have been distance between OR analysts and decision makers. However, the revolution in management science instruction and potential to train end‐user modelers has democratized OR. This makes training for policy makers and managers in the public and non‐profit sectors in Africa both feasible and highly beneficial. Existing management science courses for public and non‐profit leaders, such as those taught at Carnegie Mellon's Heinz School, could be adapted to fit the needs of educators and policy makers in Africa and disseminated via a “train the trainers” approach. A plan is sketched whereby 800,000 end‐user modelers might be trained in Africa (one for every 1000 people) at an annual cost of about $5 million/year. Such budgets are well within the range of investments in human capital formation currently being made in Africa.     

Information technology investments and firm value

Our objective in this paper is to develop a firm value model to assist IT managers and researchers in understanding the multiple effects that IT investments have on firm value. This firm value approach adds to the process-oriented approach through simultaneous evaluation of all of the factors that affect firm value. It is crucial for IT professionals to recognize the complex and diverse implications of IT investments on firm value. The implications of the firm value approach include forcing IT managers to think in terms of both industry and company-specific effects of IT investments, to consider both the magnitude and duration of competitive advantage due to IT investments, and the implications of the effect that IT investments have on risk and its relation to firm value. We demonstrate an application of the firm value framework by evaluating a major stream of research in MIS—event studies of IT investment announcements. Appendices to this paper can be found at http://www.itandfirmvalue.com.     

基于RTP报文修改的单一流映像机制研究与实现

随着因特网流媒体应用的日益普及和流行，流媒体缓存代理技术逐渐成为近年来研究的热点。本文对实现流媒体缓存代理服务器的核心技术--单一流映像机制进行了理论上的分析和探讨；并结合实际项目研究，提出了RTP协议报文修改算法，通过在流媒体缓存代理服务器端采用该算法，成功实现了单一流映像机制。实际测试结果表明，这种基
于报文修改算法的单一流映像机制十分有效。     

Estimating and quantifying the impact of using models for integration and testing

Industrial trends show that the lead time and costs of integrating and testing high-tech multi-disciplinary systems are becoming critical factors for commercial success. In our research, we developed a method for early, model-based integration and testing to reduce this criticality.Although its benefits have been demonstrated in industrial practice, the method requires certain investments to achieve these benefits, e.g. time needed for creating models. Making the necessary trade-off between investments and potential benefits to decide when modeling is profitable is a difficult task that is often based on personal intuition and experience. In this paper, we describe a method based on integration and test sequencing techniques that can be used to make quantitative impact estimations of using models for integration and testing.An industrial case study application of this method shows that it is feasible to quantify the costs and benefits of using models in terms of risk, time, and costs, such that the profitability can be determined.     

A survey on essential components of a self-sovereign identity

This paper provides an overview of the Self-Sovereign Identity (SSI) concept, focusing on four different components that we identified as essential to the architecture. Self-Sovereign Identity is enabled by the new development of blockchain technology. Through the trustless, decentralised database that is provided by a blockchain, classic Identity Management registration processes can be replaced.We start off by giving a simple overview of blockchain based SSI, introducing an architecture overview as well as relevant actors in such a system. We further distinguish two major approaches, namely the Identifier Registry Model and its extension the Claim Registry Model.Subsequently we discuss identifiers in such a system, presenting past research in the area and current approaches in SSI in the context of Zooko’s Triangle. As the user of an SSI has to be linked with his digital identifier we also discuss authentication solutions.Most central to the concept of an SSI are the verifiable claims that are presented to relying parties. Resources in the field are only loosely connected. We will provide a more coherent view of verifiable claims in regards to blockchain based SSI and clarify differences in the used terminology.Storage solutions for the verifiable claims, both on- and off-chain, are presented with their advantages and disadvantages.     

Designing a Framework for Digital KYC Processes Built on Blockchain-Based Self-Sovereign Identity

Know your customer (KYC) processes place a great burden on banks, because they are costly, inefficient, and inconvenient for customers. While blockchain technology is often mentioned as a potential solution, it is not clear how to use the technology’s advantages without violating data protection regulations and customer privacy. We demonstrate how blockchain-based self-sovereign identity (SSI) can solve the challenges of KYC. We follow a rigorous design science research approach to create a framework that utilizes SSI in the KYC process, deriving nascent design principles that theorize on blockchain’s role for SSI.     

Interactive selection of Web services under multiple objectives

The manual composition of efficient combinations of Web services becomes almost impossible as the number of services increases dramatically. When determining an appropriate set of services, managers must take into consideration given business processes, business strategy and multiple Quality of Service (QoS) objectives while ensuring the cost-efficient usage of limited resources. Because the agility with which new business requirements are adapted has a major influence on business success and poor investment decisions may thus entail corporate failure, decision makers are experiencing growing pressure to prove the value of IT investments—but they often lack appropriate multicriteria decision support tools. This paper introduces a new decision support approach that more properly addresses these challenges. We implemented this approach into a tool and evaluated the performance of two popular methods (i.e., the Analytic Hierarchy Process and the Weighted Scoring Method) by means of a real-life case study in the social security sector. It turns out that the decision support system assists decision makers in identifying investments that more precisely target their company’s business needs by allowing them to interactively determine and continually optimize service allocation according to the corporate business processes and multiple (strategic) objectives.     

A fuzzy-decision-tree approach for manufacturing technology selection exploiting experience-based information

Manufacturing technology selection is traditionally a human-driven approach where the trade-off of alternative manufacturing investments is steered by a group of experts. The problem is a semi-structured and subjective-based decision practice influenced by the experience and intuitive feeling of the decision-makers involved. This paper presents a distinct experience-based decision support system that uses factual information of historical decisions to calculate confidence factors for the successful adoption of potential technologies for a given set of requirements. A fuzzy-decision-tree algorithm is applied to provide a more objective approach given the evidence of previous manufacturing technology implementation cases. The model uses the information relationship of key technology decision variables, project requirements of an implemented technology case and the success outcome of a project to support decision problems. An empirical study was conducted at an aircraft manufacturer to support their technology decision for a typical medium complexity assembly investment project. The experimental analysis demonstrated encouraging results and practical viability of the approach.     

Activity-based justification of IT investments

Ever since investments in IT moved from operational to decision support, academics and practitioners have been looking for ways to justify the costs. Traditional approaches, such as NPV, have been shown inadequate in capturing qualitative and quantitative benefits, and techniques developed to address the issue have proved limited in their ability to link investment justification with impact assessment. Recent literature has called for the use of business processes to assess the impact of IT and the same processes can be used to justify investments in IT. The activity-based costing (ABC) approaches in the field of accounting were developed to relate investments to product profitability by allocating the burden to those that receive the most benefit. Thus, this paper uses the ABC approach to relate investments to activities, so that it can be used to justify IT investment. The paper provides a model to determine when the approach, referred to as activity-based justification, is most appropriate and its value is illustrated using a case study.     

A Borda count for collective sentiment analysis

A method for detecting potential violations of integrity constraints of concurrent transactions running under snapshot isolation (SI) is presented. Although SI provides a high level of isolation, it does not, by itself, ensure that all integrity constraints are satisfied. In particular, while current implementations of SI enforce all internal integrity constraints, in particular key constraints, they fail to enforce constraints implemented via triggers. One remedy is to turn to serializable SI (SSI), in which full serializability is guaranteed. However, SSI comes at the price of either a substantial number of false positives, or else a high cost of constructing the full direct serialization graph. In this work, a compromise approach, called constraint-preserving snapshot isolation (CPSI), is developed, which while not guaranteeing full serializability, does guarantee that all constraints, including those enforced via triggers, are satisfied. In contrast to full SSI, CPSI requires testing concurrent transactions for conflict only pairwise, and thus involves substantially less overhead while providing a foundation for resolving conflicts via negotiation rather than via abort and restart. As is the case with SSI, CPSI can result in false positives. To address this, a hybrid approach is also developed which combines CPSI with a special version of SSI called CSSI, resulting in substantially fewer false positives than would occur using either approach alone.     

Relative importance,specific investment and ownership in interorganizational systems

Implementation and maintenance of interorganizational systems (IOS) require investments by all the participating firms. Compared with intraorganizational systems, however, there are additional uncertainties and risks. This is because the benefits of IOS investment depend not only on a firm’s own decisions, but also on those of its business partners. Without appropriate levels of investment by all the firms participating in an IOS, they cannot reap the full benefits. Drawing upon the literature in institutional economics, we examine IOS ownership as a means to induce value-maximizing noncontractible investments. We model the impact of two factors derived from the theory of incomplete contracts and transaction cost economics: relative importance of investments and specificity of investments. We apply the model to a vendor-managed inventory system (VMI) in a supply chain setting. We show that when the specificity of investments is high, this is a more critical determinant of optimal ownership structure than the relative importance of investments. As technologies used in IOS become increasingly redeployable and reusable, and less specific, the relative importance of investments becomes a dominant factor. We also show that the bargaining mechanism—or the agreed upon approach to splitting the incremental payoffs—that is used affects the relationship between these factors in determining the optimal ownership structure of an IOS.

Analyzing and comparing the security of self-sovereign identity management systems through threat modeling

The concept of Self-Sovereign Identity (SSI) promises to strengthen the security and user-centricity of identity management. Since any secure online service relies on secure identity management, we comparatively analyze the intrinsic security of SSI. Thus, we adopt a hybrid threat modeling approach comprising STRIDE, attack trees, and ratings towards this unique context. Data flow diagrams of the isolated, centralized and the SSI model serve as the foundation for the assessment. The evolution of the paradigms shows an increasing complexity in security zones and communication paths between the components. We identified 35 threats to all SSI components and 15 protection measures that reduce the threats’ criticality. As a result, our research shows that the SSI paradigm’s threat surface is significantly higher compared to the traditional models. Besides the threat assessment on model level, the adapted methodology can evaluate a specific implementation. We analyzed uPort with a restricted scope to its user agent. Thus, 2 out of 10 threats were not properly addressed, leading to potential spoofing, denial, or repudiation of identity actions.

     

Profit-maximizing firm investments in customer information security

When a customer interacts with a firm, extensive personal information often is gathered without the individual's knowledge. Significant risks are associated with handling this kind of information. Providing protection may reduce the risk of the loss and misuse of private information, but it imposes some costs on both the firm and its customers. Nevertheless, customer information security breaches still may occur. They have several distinguishing characteristics: (1) typically it is hard to quantify monetary damages related to them; (2) customer information security breaches may be caused by intentional attacks, as well as through unintentional organizational and customer behaviors; and (3) the frequency of such incidents typically is low, although they can be very costly when they occur. As a result, predictive models and explanatory statistical analysis using historical data have not been effective. We present a profit optimization model for customer information security investments. Our approach is based on value-at-risk methods and operational risk modeling from financial economics. The main results of this work are that we: (1) provide guidance on the trade-offs between risk and return in customer information security investments; (2) define the range of efficient investments in technology-supported risk indemnification for sellers; (3) model how to handle government-dictated levels of investment versus self-regulation of investments in technology; and (4) characterize customer information security investment levels when the firm is able to pass some of its costs on to consumers. We illustrate our theoretical findings with empirical data from the Open Security Foundation, as a means of grounding our analysis and offering the reader intuition for the managerial interpretation of our theory and main results. The results show that we can narrow the decision set for solution providers and policy-makers based on the estimable risks and losses associated with customer information security. We also discuss the application of our approach in practice.     

Bridging the cognitive-cellular neuroscience gap empirically: a study combining physiology,modelling and fMRI

In this article, we present a mixed qualitative and quantitative approach for evaluation of information technology (IT) security investments. For this purpose, we model security scenarios by using defense trees, an extension of attack trees with countermeasures and we use economic quantitative indexes for computing the defender's return on security investment and the attacker's return on attack. We show how our approach can be used to evaluate economic profitability of countermeasures and their deterrent effect on attackers, thus providing decision makers with a useful tool for performing better evaluation of IT security investments during the risk management process.     

Simulation–optimization mechanism for expansion strategy using real option theory

A right expansion strategy can bring a company more market shares and profits, and hence increase shareholders’ equities. However, limited financial resources and various uncertainties require business practitioners to achieve their goals while controlling the risks incurred at an acceptable level. Therefore, justification of expansion investments is an important and complex topic in industry. The traditional investment analysis tools such as net present value (NPV) often tend to undervalue investment decisions. We formulate the expansion investments using real options, and develop a financial model to assess the option value. Monte Carlo simulation is considered a good way to estimate the value of the option. This valuation gives decision makers a way to choose the appropriate expansion strategy based on an integrated view of the market dynamics, but optimization is still a difficult problem to resolve. This paper presents a model of optimization under uncertainty combining system simulation with GA-based optimization to resolve the expansion problem. An industry case is used to demonstrate the application of real options to value expansion investment by using simulation–optimization. This approach also provides some new insights for the real options theory.     

Development and application of an integrated ecological modelling framework to analyze the impact of wastewater discharges on the ecological water quality of rivers

Modelling is an effective tool to investigate the ecological state of water resources. In developing countries, the impact of sanitation infrastructures (e.g. wastewater treatment plants) is typically assessed considering the achievement of legal physicochemical quality standards, but ignoring the ecological water quality (EWQ) of the receiving river. In this paper, we developed a generic integrated ecological modelling framework quantifying the impact of wastewater discharges on the EWQ of the Cauca river (Colombia). The framework is flexible enough to be used in conjunction with different approaches/models and integrates a hydraulic and physicochemical water quality model with aquatic ecological models. Two types of ecological models were developed, habitat suitability models for selected macroinvertebrate groups and ecological assessment models based on a macroinvertebrate biotic index. Four pollution control scenarios were tested. It was found that the foreseen investments in sanitation infrastructure will lead to modest improvements of the EWQ, with an increase lower than six units of the ecological index BMWP-Colombia. Advanced investments, such as the collection and treatment of all wastewater produced by the cities of Cali, Yumbo and Palmira and upgrading of the treatment systems should be considered to achieve a good EWQ. The results show that the integration of ecological models in hydraulic and physicochemical water quality models (e.g. MIKE 11) has an added value for decision support in river management and water policy. The integration of models is a key aspect for the success in environmental decision making. The main limitation of this approach is the availability of physicochemical, hydraulic and biological data that are collected simultaneously. Therefore, a change in the river monitoring strategy towards collection of data which include simultaneous measurements of these variables is required.     

Why one big picture is worth a thousand numbers: measuring intangible benefits of investments in augmented reality based assistive technology using utility effect chains and system dynamics

The body of literature in the area of IT/IS investment evaluation proposes a variety of methods and techniques for the ex-ante assessment of IT/IS investments. However, the financial evaluation of intangible benefits associated with IT/IS investments in general and investments in innovative IT/IS in particular still remains a problem area of high relevance to decision makers. As a consequence, investment decisions are still taken by practitioners as an “act of faith”. With this in mind, it is our primary aim to develop a quantification model for the financial assessment of intangible benefits concerning investments in innovative IT/IS. Based on an augmented reality and smart glasses application scenario from the construction domain, we demonstrate how intangible benefits of innovative IT/IS investments can be visualised and measured more effectively by means of utility effect chains and system dynamics prior to their incorporation into a cost–benefit analysis. Based on design science research, the quantification model is developed by means of a systematic literature review and evaluated using the augmented reality application scenario in construction. The model can serve as an aid to the managerial decision making process by providing an enhanced understanding of the various tangible and intangible benefits associated with the investment.     

An Approach to Evaluating E-Business Information Systems Projects

Capital investments in the e-business infrastructure add complexity to the IT payoff question because e-business interorganizational investments are deployed across multiple platforms, projects, vendors and partners. Traditional MIS research has been devoted to measuring the payoff from information technology (IT) investment without any specific focus on e-business. Flaws in the mature MIS performance measures seem to yield weak guidance for managers when evaluating IT success, thus diluting the potential for these measures to be adapted for use in the new e-business environment. A review of the conventional MIS payoff literature indicates that these measures may be incomplete, inaccurate, or inefficient for application to electronic commerce investments. This paper brings four new points to the e-business IT investment evaluation dialogue: (1) we first explore performance measurement validity flaws in our long established measures; (2) the paper discusses a two-by-two matrix delineating the gap between the quantitative versus qualitative performance measures of management information systems (MIS) initiatives; (3) sample e-business payoff techniques are discussed and reviewed in light of these historical imperfections, and (4) fourth, the paper proposes and describes an innovative framework derived from production theory economics for future research in evaluating e-business MIS implementations.     

Quality engineering: a new framework applied to justifying and prioritising IT investments

Quality engineering (QE) is a generic concept developed by the author that is designed to assess rigorously new investment ideas concerned with improving the quality of business processes. The aim is to provide a solid basis to decide trade-offs between varying levels of quality to be achieved and limited resources to be employed. In the present context, the approach is applied to justify and to prioritise a growing class of IT investments: systems designed to implement quality, effectiveness and strategic business vision. Companies report that purely accounting-based methods are unable to cope with these kinds of investments and that a change in investment appraisal procedures is now needed to complement financial approaches, with quality-based approaches to support the decision-making process in relation to sophisticated IT. Based on research projects at the Kobler Unit, Imperial College, where data was collected on the relative success of new IT initiatives, and in collaboration with several large companies, quality engineering has been further developed into four modules, to be applied iteratively: quality standards (QS), quality awareness (QA), quality performance indicators (QPI) and quality value (QV). Compared to traditional accounting-based frameworks, quality engineering places a new emphasis on critical success factors, structured awareness raising exercises, measurable performance indicators, distinguishing between primary systems objectives and their inevitable second-order effects, risk assessment, and strategic business integration.