Optimization of orbital assignment and specification of service areas in satellite communications

The mathematical nature of the orbital and frequency assignment problem for communications satellites is explored, and it is shown that choosing the correct permutations of the orbit locations and frequency assignments is an important step in arriving at values which satisfy the signal-quality requirements. Two methods are proposed to achieve better spectrum/orbit utilization. The first, called the delta S concept, leads to orbital assignment solutions via either mixed-integer or restricted basis entry linear programming techniques; the method guarantees good single-entry carrier-to-interference ratio results. In the second, a basis for specifying service areas is proposed for the Fixed Satellite Service. It is suggested that service areas should be specified according to the communications-demand density in conjunction with the delta S concept in order to enable the system planner to specify more satellites and provide more communications supply

Rationing and vibration monitoring of knife refiners

The subject of the research is rationing and monitoring of the vibration of knife refiners. GOST 26493-85, specifying the permissible values of the vibration amplitude of the mills, is outdated. This standard does not take into account new designs of knife refiners and the requirements of national and international standards. It is proposed to establish two criteria for assessing the vibration state of the refiners. The first criterion normalizes the amplitude of vibration in octave strips of frequencies, while the second criterion specifies the vibration trend on the general level. It is proposed to use the vibration velocity as the measured parameter. The necessity of separating the refiners into two groups was revealed: with a disc or cone diameter up to 1000 mm and with a diameter over 1000 mm. The boundaries of zones and vibration trends are determined: good; satisfactorily; need improvement and unacceptable. After that, a decision is made to limit the functioning of these machines (prevention and stop). The introduction of standards and vibration monitoring will accelerate the transition to repairs of machines on the technical condition. Methods of rationing and monitoring can be used in other industries, for example, in the mining and metallurgical industries. © Published under licence by IOP Publishing Ltd

Requirements Discovery for a Production Management Software

Due to the expanding Condition Based Maintenance (CBM) business at Wärtsilä Oyj a software tool was needed to ease and secure the maintainability of the installed base, delivery requirements, contract and invoicing information. Another aim with this tool was to achieve a degree of predictability of the CBM services by having information available about forthcoming requests for CBM systems and services. As a result, a tool with up-to-date information would serve many stakeholders with all available CBM related information but also remarkably reduce the work load needed to maintain this information manually. The objective of this thesis was to gather and document the requirements. For the requirements discovery a use case based requirements elicitation technique was selected. It was selected because use cases can be documented in a structured way and also because they are a good tool to communicate the behavioural functions of a system between users and software developers. Requirements were also discovered by studying documents, tools, and process, but also by arranging interviews and having discussions with the stakeholders. All the requirements were documented in a Software Requirements Specification using a template from IEEE Std 830-1998. The result of this thesis is a Software Requirements Specification that defines the requirements for this new tool. It was observed that even though it takes only a few minutes to learn read use cases, learning to write good use cases requires much more effort. In addition, the use cases are an important input when making the functional design specification, but they also serve as a base for designing the test cases that the new software will have to meet. Finally, the most important lesson learned was the importance of specifying software requirements that cannot be ignored.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

RS4AAL: A Process for Specifying and Analyzing Non-Functional Requirements in Ambient Assisted Living Systems

Context: The increasing life expectancy of the world’s population is a reality, and combined with sharply declining birth rates, these advances in life expectancy could lead to a rapidly aging population around the world. Technologies such as Ambient Assisted Living (AAL) can provide services that enable older people to live independently, safely and healthily. During system development, it is important to ensure good specification of Non-Functional Requirements (NFR). These are requirements that define how the system will behave in certain situations and may impact the end goal of the software if not considered during the analysis and development of the project. Aims: To meet and identify all the needs and functions provided to the users of the system, this article provides a process for specifying and analyzing nonfunctional requirements in Ambient Assisted Living, called RS4AAL, which helps the requirements engineer to specify and analyze the important requirements in the development of this system by capturing the requirements with techniques such as storytelling, reuse, and legal requirements. Results: Based on systematic mapping, key nonfunctional requirements for the Health and Care in Life subdomain were identified, as well as some legal requirements that may impact system development. Conclusions: A key finding is that the personal context of older people, legal requirements such as ISO/PRF TS 823042, and AAL Guidelines for Ethics, Data Privacy and Security directly affect the specification of non-functional requirements and the design of systems. The RS4AAL helps with this mapping by showing the requirements engineer what to consider when designing AAL systems

Learning Density-Based Correlated Equilibria for Markov Games

Correlated Equilibrium (CE) is a well-established solution concept that captures coordination among agents and enjoys good algorithmic properties. In real-world multi-agent systems, in addition to being in an equilibrium, agents' policies are often expected to meet requirements with respect to safety, and fairness. Such additional requirements can often be expressed in terms of the state density which measures the state-visitation frequencies during the course of a game. However, existing CE notions or CE-finding approaches cannot explicitly specify a CE with particular properties concerning state density; they do so implicitly by either modifying reward functions or using value functions as the selection criteria. The resulting CE may thus not fully fulfil the state-density requirements. In this paper, we propose Density-Based Correlated Equilibria (DBCE), a new notion of CE that explicitly takes state density as selection criterion. Concretely, we instantiate DBCE by specifying different state-density requirements motivated by real-world applications. To compute DBCE, we put forward the Density Based Correlated Policy Iteration algorithm for the underlying control problem. We perform experiments on various games where results demonstrate the advantage of our CE-finding approach over existing methods in scenarios with state-density concerns

Specifying Requirements for Modern Software Development: A Test-Oriented Methodology

Most modern computer systems operate in distributed environments. To develop and test such applications, services, and systems, it is necessary to consider the physical devices, architectures, communication, security and deployment mechanisms involved. However, the requirements’ specification process still replicates that of traditional applications: details remain implicit and are hidden in the description. As a result, specifications are difficult to identify and, ultimately, tests are designed in the traditional way: they overlook constraints and fail to achieve the desired effects. Our objective is to design a methodology for specifying requirements in both traditional software and applications deployed in distributed environments. We present an iterative and incremental requirements specification methodology. This methodology allows us to describe functional requirements and incorporate non-functional or quality constraints, which is the main contribution of this proposal. To ensure that quality requirements are specified during the design phase, the methodology proposes a series of phases, stages and artefacts that ensure the discovery and consideration of these requirements. In order to find out the strengths and weaknesses of our methodology, we have carried out a comparative study with other similar proposals in the literature. To this end, evaluation criteria were defined by considering standards and good practices in Requirements Engineering. The results of the comparative study show that our methodology constitutes a solid procedure for a detailed requirements specification from the beginning of the software development cycle. This represents an advance over the rest of the proposals studied. Our methodology contributes to the simplification of the design and execution phases of software testing, enabling traceability between the specified requirements and the designed test cases

Iterative criteria-based approach to engineering the requirements of software development methodologies

Software engineering endeavours are typically based on and governed by the requirements of the target software; requirements identification is therefore an integral part of software development methodologies. Similarly, engineering a software development methodology (SDM) involves the identification of the requirements of the target methodology. Methodology engineering approaches pay special attention to this issue; however, they make little use of existing methodologies as sources of insight into methodology requirements. The authors propose an iterative method for eliciting and specifying the requirements of a SDM using existing methodologies as supplementary resources. The method is performed as the analysis phase of a methodology engineering process aimed at the ultimate design and implementation of a target methodology. An initial set of requirements is first identified through analysing the characteristics of the development situation at hand and/or via delineating the general features desirable in the target methodology. These initial requirements are used as evaluation criteria; refined through iterative application to a select set of relevant methodologies. The finalised criteria highlight the qualities that the target methodology is expected to possess, and are therefore used as a basis for de. ning the final set of requirements. In an example, the authors demonstrate how the proposed elicitation process can be used for identifying the requirements of a general object-oriented SDM. Owing to its basis in knowledge gained from existing methodologies and practices, the proposed method can help methodology engineers produce a set of requirements that is not only more complete in span, but also more concrete and rigorous

Understanding and Specifying Information Security Needs to Support the Delivery of High Quality Security Services

In this paper we present an approach for specifying and prioritizing information security requirements in organizations. It is important to prioritize security requirements since hundred per cent security is\ud not achievable and the limited resources available should be directed to satisfy the most important ones. We propose to explicitly link security requirements with the organization’s business vision, i.e. to provide business\ud rationale for security requirements. The rationale is then used as a basis for comparing the importance of different security requirements.\ud Furthermore we discuss how to integrate the aforementioned solution concepts into a service level management process for security services, which is an important step in IT Governance. We validate our approach by way of a focus group session