Henk Zijm | University of Twente (original) (raw)
Papers by Henk Zijm
In this paper we study a system consisting of twoi dentical servers, each with exponentially dist... more In this paper we study a system consisting of twoi dentical servers, each with exponentially distributed service times. Jobs arrive according to a Poisson stream. On arrivalajob joins the shortest queue and in case both queues have equal lengths, he joins either queue with probability 1 ⁄2.B yu sing a compensation method, we showthat the stationary queue length distribution can be expressed as an infinite linear combination of product forms. Explicit relations are found for these product forms, as well as for the coefficients in the linear combination. These analytic results offer an elegant and efficient numerical algorithm, with effective bounds on the error of each partial sum.
Operations, Logistics and Supply Chain Management
Journal of Environmental Management
International Journal of Advanced Manufacturing Technology - INT J ADV MANUF TECHNOL, 1992
In this paper we investigate for which random walks with three or more dimensions the compensatio... more In this paper we investigate for which random walks with three or more dimensions the compensation approach can be used to determine the equilibrium distribution. As we will see, the compensation approach is not appropriate for the symmetric shortest queue system with three queues, but for the 2 x 3 buffered switch it is. By using this compensation approach, we show that for the 2 x 3 buffered switch the equilibrium distribution can be expressed as a linear combination of six series of binary trees of product-form (geometric) distributions.
International Journal of Advanced Manufacturing Technology - INT J ADV MANUF TECHNOL, 1992
In this paper we investigate for which random walks with three or more dimensions the compensatio... more In this paper we investigate for which random walks with three or more dimensions the compensation approach can be used to determine the equilibrium distribution. As we will see, the compensation approach is not appropriate for the symmetric shortest queue system with three queues, but for the 2 x 3 buffered switch it is. By using this compensation approach, we show that for the 2 x 3 buffered switch the equilibrium distribution can be expressed as a linear combination of six series of binary trees of product-form (geometric) distributions.
Management Science, Aug 1, 1996
We address the NP-hard problem of scheduling n independent jobs with release dates, due dates, an... more We address the NP-hard problem of scheduling n independent jobs with release dates, due dates, and family setup times on a single machine to minimize the maximum lateness. This problem arises from the constant tug-of-war going on in manufacturing between efficient production and delivery performance, between maximizing machine utilization by batching similar jobs and maximizing customers' satisfaction by completing jobs before their due dates. We develop a branch-and-bound algorithm, and our ...
Management Science, Aug 1, 1996
We address the NP-hard problem of scheduling n independent jobs with release dates, due dates, an... more We address the NP-hard problem of scheduling n independent jobs with release dates, due dates, and family setup times on a single machine to minimize the maximum lateness. This problem arises from the constant tug-of-war going on in manufacturing between efficient production and delivery performance, between maximizing machine utilization by batching similar jobs and maximizing customers' satisfaction by completing jobs before their due dates. We develop a branch-and-bound algorithm, and our ...
IIE Transactions, 2000
In this paper, we study the operational availability of a complex technical system consisting of ... more In this paper, we study the operational availability of a complex technical system consisting of several components. The components are subject to breakdowns, and hence for each component a limited number of spare parts are held in stock. If a system's component fails and it can not be replaced immediately, due to a lack of spares, the system becomes unavailable until a new component is installed. Failed components are disposed of and hence, to keep the spare parts stock at an appropriate level, new components have to be purchased. We assume that only a limited annual budget is available for procurement, while any further procurement requires a considerable lead time. We investigate at an aggregate level what budgets are needed to attain a target availability level for the system. In addition, we develop various operational strategies for spending the annual budget during each year. Numerical results indicate that the so-called Balance Focussed strategy provides the best results in terms of system availability as a function of time.
Or Spektrum, 1993
Summary In this paper we study a multiprogramming system consisting of an input-output unit (IO u... more Summary In this paper we study a multiprogramming system consisting of an input-output unit (IO unit) and a central processor (CP). This system can be represented by a continuous time Markov process with states (m, n), wherem andn denote the number of jobs at the CP and the IO unit respectively. The computation of the equilibrium distribution {pm,n} of this
Or Spektrum, 1993
Summary In this paper we study a multiprogramming system consisting of an input-output unit (IO u... more Summary In this paper we study a multiprogramming system consisting of an input-output unit (IO unit) and a central processor (CP). This system can be represented by a continuous time Markov process with states (m, n), wherem andn denote the number of jobs at the CP and the IO unit respectively. The computation of the equilibrium distribution {pm,n} of this
OR Spectrum, 2001
DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:
… of Operational Research, 2000
In this paper we pf(~s(mt a reference framework and a classification of warehouse design and cont... more In this paper we pf(~s(mt a reference framework and a classification of warehouse design and control problems. Based on this framework, we review the existing literature on warehousing systems and indicate important gaps. In particular, we emphasi:r.e the need for design oriented studies, a..'l opposed to the strong analysis oriented research on isolated subproblems that seems to be dominant in the current literature.
International Journal of Production Economics
Expert Systems with Applications
The task of designing a recommender system is a complex process. Because of the many technologica... more The task of designing a recommender system is a complex process. Because of the many technological advancements that may be included in a recommender system, engineers are faced with a fast growing number of design related decisions to be taken. Unfortunately, there is no general approach yet for decision makers that can act as a framework guiding the design of a recommender system. The rich collection of literature on recommender systems, though, offers a great source to identify the key areas where these decisions need to be taken. In this paper, we survey existing literature with the aim of building a recommender system model inspired by Osterwalder's canvas theory. The result of our semi-structured synthesis is a novel design approach in the form of a canvas for designing recommender systems. This work provides a better understanding and can serve as a guide for decision making in recommender system design.
Engineering Applications of Artificial Intelligence
European Journal of Operational Research
Journal of Business Logistics
Environmental Modelling & Software
Management Research Review
In the context of the circular economy, cooperation among agriculture, animal farming and bioener... more In the context of the circular economy, cooperation among agriculture, animal farming and bioenergy production based on local second generation biomass use and by-product exchange may yield innovative regional business models. Actors from such different sectors can enhance the development of a circular economy on a local level, gaining economic advantages for themselves and contributing to generate environmental benefits. However, as second generation biomass is not produced upon demand but emerges as secondary output, spatial, technical, and technological variables cause uncertainties on economic benefits for the actors involved. These uncertainties may impede local actors to get engaged with innovative circular economic business models, thus hindering the generation of environmental advantages. This paper proposes a circular economy model where animal manure is used to produce biogas and alternative fertilizer, where the latter, in turn, is used in agricultural activities in a regional network of suppliers and producers. The empirical case of this study is based on the use of cattle and pig manure in biogas production in a case example. The impacts of the above-mentioned variables on the economic returns for each actor are investigated numerically using an enterprise input-output approach. The analysis identifies under which conditions cooperation can be beneficial for all actors involved. Accordingly, different cooperation modes are proposed from an organizational perspective. The paper provides theoretical, practical and managerial contributions for the regional actors to design such circular economic business models with reduced environmental impacts. Implications derived from resource and energy savings in the specific case of biogas production are also interpreted from a regional policy-making perspective.
In this paper we study a system consisting of twoi dentical servers, each with exponentially dist... more In this paper we study a system consisting of twoi dentical servers, each with exponentially distributed service times. Jobs arrive according to a Poisson stream. On arrivalajob joins the shortest queue and in case both queues have equal lengths, he joins either queue with probability 1 ⁄2.B yu sing a compensation method, we showthat the stationary queue length distribution can be expressed as an infinite linear combination of product forms. Explicit relations are found for these product forms, as well as for the coefficients in the linear combination. These analytic results offer an elegant and efficient numerical algorithm, with effective bounds on the error of each partial sum.
Operations, Logistics and Supply Chain Management
Journal of Environmental Management
International Journal of Advanced Manufacturing Technology - INT J ADV MANUF TECHNOL, 1992
In this paper we investigate for which random walks with three or more dimensions the compensatio... more In this paper we investigate for which random walks with three or more dimensions the compensation approach can be used to determine the equilibrium distribution. As we will see, the compensation approach is not appropriate for the symmetric shortest queue system with three queues, but for the 2 x 3 buffered switch it is. By using this compensation approach, we show that for the 2 x 3 buffered switch the equilibrium distribution can be expressed as a linear combination of six series of binary trees of product-form (geometric) distributions.
International Journal of Advanced Manufacturing Technology - INT J ADV MANUF TECHNOL, 1992
In this paper we investigate for which random walks with three or more dimensions the compensatio... more In this paper we investigate for which random walks with three or more dimensions the compensation approach can be used to determine the equilibrium distribution. As we will see, the compensation approach is not appropriate for the symmetric shortest queue system with three queues, but for the 2 x 3 buffered switch it is. By using this compensation approach, we show that for the 2 x 3 buffered switch the equilibrium distribution can be expressed as a linear combination of six series of binary trees of product-form (geometric) distributions.
Management Science, Aug 1, 1996
We address the NP-hard problem of scheduling n independent jobs with release dates, due dates, an... more We address the NP-hard problem of scheduling n independent jobs with release dates, due dates, and family setup times on a single machine to minimize the maximum lateness. This problem arises from the constant tug-of-war going on in manufacturing between efficient production and delivery performance, between maximizing machine utilization by batching similar jobs and maximizing customers' satisfaction by completing jobs before their due dates. We develop a branch-and-bound algorithm, and our ...
Management Science, Aug 1, 1996
We address the NP-hard problem of scheduling n independent jobs with release dates, due dates, an... more We address the NP-hard problem of scheduling n independent jobs with release dates, due dates, and family setup times on a single machine to minimize the maximum lateness. This problem arises from the constant tug-of-war going on in manufacturing between efficient production and delivery performance, between maximizing machine utilization by batching similar jobs and maximizing customers' satisfaction by completing jobs before their due dates. We develop a branch-and-bound algorithm, and our ...
IIE Transactions, 2000
In this paper, we study the operational availability of a complex technical system consisting of ... more In this paper, we study the operational availability of a complex technical system consisting of several components. The components are subject to breakdowns, and hence for each component a limited number of spare parts are held in stock. If a system's component fails and it can not be replaced immediately, due to a lack of spares, the system becomes unavailable until a new component is installed. Failed components are disposed of and hence, to keep the spare parts stock at an appropriate level, new components have to be purchased. We assume that only a limited annual budget is available for procurement, while any further procurement requires a considerable lead time. We investigate at an aggregate level what budgets are needed to attain a target availability level for the system. In addition, we develop various operational strategies for spending the annual budget during each year. Numerical results indicate that the so-called Balance Focussed strategy provides the best results in terms of system availability as a function of time.
Or Spektrum, 1993
Summary In this paper we study a multiprogramming system consisting of an input-output unit (IO u... more Summary In this paper we study a multiprogramming system consisting of an input-output unit (IO unit) and a central processor (CP). This system can be represented by a continuous time Markov process with states (m, n), wherem andn denote the number of jobs at the CP and the IO unit respectively. The computation of the equilibrium distribution {pm,n} of this
Or Spektrum, 1993
Summary In this paper we study a multiprogramming system consisting of an input-output unit (IO u... more Summary In this paper we study a multiprogramming system consisting of an input-output unit (IO unit) and a central processor (CP). This system can be represented by a continuous time Markov process with states (m, n), wherem andn denote the number of jobs at the CP and the IO unit respectively. The computation of the equilibrium distribution {pm,n} of this
OR Spectrum, 2001
DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:
… of Operational Research, 2000
In this paper we pf(~s(mt a reference framework and a classification of warehouse design and cont... more In this paper we pf(~s(mt a reference framework and a classification of warehouse design and control problems. Based on this framework, we review the existing literature on warehousing systems and indicate important gaps. In particular, we emphasi:r.e the need for design oriented studies, a..'l opposed to the strong analysis oriented research on isolated subproblems that seems to be dominant in the current literature.
International Journal of Production Economics
Expert Systems with Applications
The task of designing a recommender system is a complex process. Because of the many technologica... more The task of designing a recommender system is a complex process. Because of the many technological advancements that may be included in a recommender system, engineers are faced with a fast growing number of design related decisions to be taken. Unfortunately, there is no general approach yet for decision makers that can act as a framework guiding the design of a recommender system. The rich collection of literature on recommender systems, though, offers a great source to identify the key areas where these decisions need to be taken. In this paper, we survey existing literature with the aim of building a recommender system model inspired by Osterwalder's canvas theory. The result of our semi-structured synthesis is a novel design approach in the form of a canvas for designing recommender systems. This work provides a better understanding and can serve as a guide for decision making in recommender system design.
Engineering Applications of Artificial Intelligence
European Journal of Operational Research
Journal of Business Logistics
Environmental Modelling & Software
Management Research Review
In the context of the circular economy, cooperation among agriculture, animal farming and bioener... more In the context of the circular economy, cooperation among agriculture, animal farming and bioenergy production based on local second generation biomass use and by-product exchange may yield innovative regional business models. Actors from such different sectors can enhance the development of a circular economy on a local level, gaining economic advantages for themselves and contributing to generate environmental benefits. However, as second generation biomass is not produced upon demand but emerges as secondary output, spatial, technical, and technological variables cause uncertainties on economic benefits for the actors involved. These uncertainties may impede local actors to get engaged with innovative circular economic business models, thus hindering the generation of environmental advantages. This paper proposes a circular economy model where animal manure is used to produce biogas and alternative fertilizer, where the latter, in turn, is used in agricultural activities in a regional network of suppliers and producers. The empirical case of this study is based on the use of cattle and pig manure in biogas production in a case example. The impacts of the above-mentioned variables on the economic returns for each actor are investigated numerically using an enterprise input-output approach. The analysis identifies under which conditions cooperation can be beneficial for all actors involved. Accordingly, different cooperation modes are proposed from an organizational perspective. The paper provides theoretical, practical and managerial contributions for the regional actors to design such circular economic business models with reduced environmental impacts. Implications derived from resource and energy savings in the specific case of biogas production are also interpreted from a regional policy-making perspective.