Using a simulation model for capacity management

A simulation model has been constructed of a valve manufacturing plant with the aim of assessing capacity requirements in response to a forecast increase in demand. The plant provides a weekly cycle of valves of varying types, based on a yearly production plan. Production control is provided by a just-in-time type system to minimise inventory. The simulation model investigates the effect on production lead time of a range of valve sequences into the plant. The study required the collection of information from a variety of sources, and a model that reflected the true capabilities of the production system. The simulation results convinced management that substantial changes were needed in order to meet demand. The case highlights the use of simulation in enabling a manager to quantify operational scenarios and thus provide a rational basis on which to take decisions on meeting performance criteria.

Transferring knowledge of manufacturing techniques in multinational corporations:preliminary findings

With the growth of the multinational corporation (MNC) has come the need to understand how parent companies transfer knowledge to, and manage the operations of, their subsidiaries. This is of particular interest to manufacturing companies transferring their operations overseas. Japanese companies in particular have been pioneering in this regard, with techniques such as the Toyota Production System (TPS) for transferring the ethos of Japanese manufacturing and maintaining quality and control in overseas subsidiaries. A great deal has been written about the process of transferring Japanese manufacturing techniques, but much less is understood about how the subsidiaries themselves, which are required to make use of such techniques, actually acquire and incorporate them into their operations. The research on which this paper is based therefore examines how, from the perspective of the subsidiary, knowledge of manufacturing techniques is transferred from the parent company. There is clearly a need to take a practice-based view to understanding how the local managers and operatives incorporate knowledge about manufacturing techniques into their working practices. In-depth qualitative research was, therefore, conducted in the subsidiary of a Japanese multinational, Denso Corporation, involving three main manufacturing initiatives (or philosophies), namely ‘TPS’, ‘TPM’ and ‘TS’. The case data were derived from 52 in-depth interviews with project members, moderate participant observations, and documentations. The aim of this paper is to present the preliminary findings from the case analyses. The research contributes to our understanding of knowledge transfer in relation to the circumstances of the selection between adaptation and replication of knowledge in the subsidiary from its parent. In particular this understanding relates to transfer across different flows and levels in the organisational hierarchy, how the whole process is managed, and also how modification takes place.

Beyond defoaming:the effects of antifoams on bioprocesses productivity

Antifoams are often added to bioprocesses with little knowledge of their impact on the cells or product. However, it is known that certain antifoams can affect the growth rates of both prokaryotic and eukaryotic organisms in addition to changing surface properties such as lipid content, resulting in changes to permeability. This in turn can be beneficial to a recombinant protein production system for soluble proteins, as has been demonstrated by increased secretion of a-amylase and GFP, or achievement of greater yields of protein due to increased biomass. However, in some cases, certain concentrations of antifoams appear to have a detrimental effect upon cells and protein production, and the effects vary depending upon the protein being expressed. These findings emphasise the importance of optimising and understanding antifoam addition to bioprocesses.

Optical 2R regeneration at 40 Gbit/s using saturable absorber in long-haul dispersion-managed fiber links

The optical regeneration is an attractive method to improve the performance of long-distance data transmission, though its application in high-speed fiber systems requires careful design consideration/optimization. In this letter we investigate 40 Gbit/s dispersion-managed fiber transmission with optical 2R regeneration based on quantum well saturable absorber and highly non-linear fiber. We demonstrate through numerical modeling a feasibility of a single channel transmission over 10,000 km using optimized system design. © 2003 Elsevier B.V. All rights reserved.

Modulation instability in high power laser amplifiers

The modulation instability (MI) is one of the main factors responsible for the degradation of beam quality in high-power laser systems. The so-called B-integral restriction is commonly used as the criteria for MI control in passive optics devices. For amplifiers the adiabatic model, assuming locally the Bespalov-Talanov expression for MI growth, is commonly used to estimate the destructive impact of the instability. We present here the exact solution of MI development in amplifiers. We determine the parameters which control the effect of MI in amplifiers and calculate the MI growth rate as a function of those parameters. The safety range of operational parameters is presented. The results of the exact calculations are compared with the adiabatic model, and the range of validity of the latest is determined. We demonstrate that for practical situations the adiabatic approximation noticeably overestimates MI. The additional margin of laser system design is quantified. © 2010 Optical Society of America.

One Approach to Knowledge Mapping for International Student Portal

* The work is partly supported by RFFI grant 08-07-00062-a

An Architectural Model of Rights Management Framework for Information Systems

The demands towards the contemporary information systems are constantly increasing. In a dynamic business environment an organization has to be prepared for sudden growth, shrinking or other type of reorganization. Such change would bring the need of adaptation of the information system, servicing the company. The association of access rights to parts of the system with users, groups of users, user roles etc. is of great importance to defining the different activities in the company and the restrictions of the access rights for each employee, according to his status. The mechanisms for access rights management in a system are taken in account during the system design. In most cases they are build in the system. This paper offers an approach in user rights framework development that is applicable in information systems. This work presents a reusable extendable mechanism that can be integrated in information systems.

Protection schemes for meshed VSC-HVDC transmission systems for large-scale offshore wind farms

This chapter discusses network protection of high-voltage direct current (HVDC) transmission systems for large-scale offshore wind farms where the HVDC system utilizes voltage-source converters. The multi-terminal HVDC network topology and protection allocation and configuration are discussed with DC circuit breaker and protection relay configurations studied for different fault conditions. A detailed protection scheme is designed with a solution that does not require relay communication. Advanced understanding of protection system design and operation is necessary for reliable and safe operation of the meshed HVDC system under fault conditions. Meshed-HVDC systems are important as they will be used to interconnect large-scale offshore wind generation projects. Offshore wind generation is growing rapidly and offers a means of securing energy supply and addressing emissions targets whilst minimising community impacts. There are ambitious plans concerning such projects in Europe and in the Asia-Pacific region which will all require a reliable yet economic system to generate, collect, and transmit electrical power from renewable resources. Collective offshore wind farms are efficient and have potential as a significant low-carbon energy source. However, this requires a reliable collection and transmission system. Offshore wind power generation is a relatively new area and lacks systematic analysis of faults and associated operational experience to enhance further development. Appropriate fault protection schemes are required and this chapter highlights the process of developing and assessing such schemes. The chapter illustrates the basic meshed topology, identifies the need for distance evaluation, and appropriate cable models, then details the design and operation of the protection scheme with simulation results used to illustrate operation. © Springer Science+Business Media Singapore 2014.

Large volume metrology technologies for the light controlled factory

In the Light Controlled Factory part-to-part assembly and reduced weight will be enabled through the use of predictive fitting processes; low cost high accuracy reconfigurable tooling will be made possible by active compensation; improved control will allow accurate robotic machining; and quality will be improved through the use of traceable uncertainty based quality control throughout the production system. A number of challenges must be overcome before this vision will be realized; 1) controlling industrial robots for accurate machining; 2) compensation of measurements for thermal expansion; 3) Compensation of measurements for refractive index changes; 4) development of Embedded Metrology Tooling for in-tooling measurement and active tooling compensation; and 5) development of Software for the Planning and Control of Integrated Metrology Networks based on Quality Control with Uncertainty Evaluation and control systems for predictive processes. This paper describes how these challenges are being addressed, in particular the central challenge of developing large volume measurement process models within an integrated dimensional variation management (IDVM) system.

Manageable Workflows for Processing Parallel Sequencing Data

ACM Computing Classification System (1998): D.2.11, D.1.3, D.3.1, J.3, C.2.4.

Advanced predictive-analysis-based decision support for collaborative logistics networks

Purpose – The purpose of this paper is to examine challenges and potential of big data in heterogeneous business networks and relate these to an implemented logistics solution. Design/methodology/approach – The paper establishes an overview of challenges and opportunities of current significance in the area of big data, specifically in the context of transparency and processes in heterogeneous enterprise networks. Within this context, the paper presents how existing components and purpose-driven research were combined for a solution implemented in a nationwide network for less-than-truckload consignments. Findings – Aside from providing an extended overview of today’s big data situation, the findings have shown that technical means and methods available today can comprise a feasible process transparency solution in a large heterogeneous network where legacy practices, reporting lags and incomplete data exist, yet processes are sensitive to inadequate policy changes. Practical implications – The means introduced in the paper were found to be of utility value in improving process efficiency, transparency and planning in logistics networks. The particular system design choices in the presented solution allow an incremental introduction or evolution of resource handling practices, incorporating existing fragmentary, unstructured or tacit knowledge of experienced personnel into the theoretically founded overall concept. Originality/value – The paper extends previous high-level view on the potential of big data, and presents new applied research and development results in a logistics application.

Stratégiai paradigmaváltás szervezeti verseny(képesség) és az Operations management központi szerepe (Central role of strategic paradigm change, corporate competitiveness and operations management)

Az elmúlt két évtized folyamán a menedzserek megtanultak a megújult szabályok szerint játszani. Tudatosították, hogy a vállalatuk eredményes navigálásához folyamatosan figyelniük és adaptálniuk kell a legújabb módszereket, elméleteket. Jelen tanulmányával a szerző ezt a folyamatot kívánja segíteni, valamint arra az alapvető kérdésre keresi a választ, hogy érdemes-e a rendkívül gyorsan változó világban hosszabb távú célok meghatározásával foglalkozni, és ha igen, akkor mire összpontosítsák a vállalatok erőfeszítéseiket. Milyen részletezettséggel, milyen módon határozzák meg az elképzeléseiket úgy, hogy közben megőrizzék a vállalat flexibilitását, a változások idején nélkülözhetetlen agilitást. A szerző arra vállalkozik, hogy feltárja a stratégiai paradigmaváltás fejlődését, a termelési stratégia, az operations management központi meghatározó szereppé válását, valamint áttekintse a termelési és szolgáltatási rendszervezetés (OM) elveinek, eszközeinek, módszereinek fejlődését, kölcsönhatását, összefüggéseit. _______ Change of paradigm has taken place in strategic planning. Fight for position turned into a fight of movement. Companies strive to achieve individual, not copyable organizational performance, as well as to realize their business strategies by means of value generating, proactive approach. Operative management now placed in the focus of production strategy is becoming the compass, the driving force of leadership. The management of production and service systems has grown into independent scientific disciplines. It yielded such principles, tools and methods which are present as world-renowned blueprints (scientific tools) in the field of maintaining and developing corporate performance. In the present study the author specifies and discusses the tools of operative management as criteria of value generation aiming at quality and cost efficiency. He analyses the backto- back character, interrelationship of quality, TQM (Total Quality Management), TPS (Toyota Production System) and JIT (Just in Time). He examines the effects thereof on corporate performance where significant and strong relationship can be demonstrated in case there is an ability to plan and develop new products. The current new OM (Operations Management) techniques increasingly rely upon the quality of human resources, the permanent improvement of procedures as well as focusing on tight cooperation with suppliers/customers. Supply chain management, core competence management, service management now represent a “new generation” of the OM methods, processes, serving at the same time as basis and starting point for expectable future techniques as well.

An indexing structure and application model for vehicles moving on road networks

Moving objects database systems are the most challenging sub-category among Spatio-Temporal database systems. A database system that updates in real-time the location information of GPS-equipped moving vehicles has to meet even stricter requirements. Currently existing data storage models and indexing mechanisms work well only when the number of moving objects in the system is relatively small. This dissertation research aimed at the real-time tracking and history retrieval of massive numbers of vehicles moving on road networks. A total solution has been provided for the real-time update of the vehicles' location and motion information, range queries on current and history data, and prediction of vehicles' movement in the near future. ^ To achieve these goals, a new approach called Segmented Time Associated to Partitioned Space (STAPS) was first proposed in this dissertation for building and manipulating the indexing structures for moving objects databases. ^ Applying the STAPS approach, an indexing structure of associating a time interval tree to each road segment was developed for real-time database systems of vehicles moving on road networks. The indexing structure uses affordable storage to support real-time data updates and efficient query processing. The data update and query processing performance it provides is consistent without restrictions such as a time window or assuming linear moving trajectories. ^ An application system design based on distributed system architecture with centralized organization was developed to maximally support the proposed data and indexing structures. The suggested system architecture is highly scalable and flexible. Finally, based on a real-world application model of vehicles moving in region-wide, main issues on the implementation of such a system were addressed. ^

Framework for enterprise systems engineering

This research aimed at developing a research framework for the emerging field of enterprise systems engineering (ESE). The framework consists of an ESE definition, an ESE classification scheme, and an ESE process. This study views an enterprise as a system that creates value for its customers. Thus, developing the framework made use of system theory and IDEF methodologies. This study defined ESE as an engineering discipline that develops and applies systems theory and engineering techniques to specification, analysis, design, and implementation of an enterprise for its life cycle. The proposed ESE classification scheme breaks down an enterprise system into four elements. They are work, resources, decision, and information. Each enterprise element is specified with four system facets: strategy, competency, capacity, and structure. Each element-facet combination is subject to the engineering process of specification, analysis, design, and implementation, to achieve its pre-specified performance with respect to cost, time, quality, and benefit to the enterprise. This framework is intended for identifying research voids in the ESE discipline. It also helps to apply engineering and systems tools to this emerging field. It harnesses the relationships among various enterprise aspects and bridges the gap between engineering and management practices in an enterprise. The proposed ESE process is generic. It consists of a hierarchy of engineering activities presented in an IDEF0 model. Each activity is defined with its input, output, constraints, and mechanisms. The output of an ESE effort can be a partial or whole enterprise system design for its physical, managerial, and/or informational layers. The proposed ESE process is applicable to a new enterprise system design or an engineering change in an existing system. The long-term goal of this study aims at development of a scientific foundation for ESE research and development.

Robust and high current cold electron source based on carbon nanotube field emitters and electron multiplier microchannel plate

The aim of this research was to demonstrate a high current and stable field emission (FE) source based on carbon nanotubes (CNTs) and electron multiplier microchannel plate (MCP) and design efficient field emitters. In recent years various CNT based FE devices have been demonstrated including field emission displays, x-ray source and many more. However to use CNTs as source in high powered microwave (HPM) devices higher and stable current in the range of few milli-amperes to amperes is required. To achieve such high current we developed a novel technique of introducing a MCP between CNT cathode and anode. MCP is an array of electron multipliers; it operates by avalanche multiplication of secondary electrons, which are generated when electrons strike channel walls of MCP. FE current from CNTs is enhanced due to avalanche multiplication of secondary electrons and in addition MCP also protects CNTs from irreversible damage during vacuum arcing. Conventional MCP is not suitable for this purpose due to the lower secondary emission properties of their materials. To achieve higher and stable currents we have designed and fabricated a unique ceramic MCP consisting of high SEY materials. The MCP was fabricated utilizing optimum design parameters, which include channel dimensions and material properties obtained from charged particle optics (CPO) simulation. Child Langmuir law, which gives the optimum current density from an electron source, was taken into account during the system design and experiments. Each MCP channel consisted of MgO coated CNTs which was chosen from various material systems due to its very high SEY. With MCP inserted between CNT cathode and anode stable and higher emission current was achieved. It was ∼25 times higher than without MCP. A brighter emission image was also evidenced due to enhanced emission current. The obtained results are a significant technological advance and this research holds promise for electron source in new generation lightweight, efficient and compact microwave devices for telecommunications in satellites or space applications. As part of this work novel emitters consisting of multistage geometry with improved FE properties were was also developed.