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  <doc>
    <id>3339</id>
    <completedYear>2008</completedYear>
    <publishedYear>2008</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>2647</pageFirst>
    <pageLast>2648</pageLast>
    <pageNumber/>
    <edition/>
    <issue>12</issue>
    <volume>308</volume>
    <type>article</type>
    <publisherName>Elsevier</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">A note on degree-constrained subgraphs</title>
    <parentTitle language="eng">Discrete Mathematics</parentTitle>
    <author>A. Frank</author>
    <author>L. Chi Lau</author>
    <author>Jácint Szabó</author>
    <collection role="institutes" number="optimization">Mathematical Optimization</collection>
    <collection role="institutes" number="aopt">Applied Optimization</collection>
  </doc>
  <doc>
    <id>1234</id>
    <completedYear/>
    <publishedYear/>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
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    <type>reportzib</type>
    <publisherName/>
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    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2011-03-15</completedDate>
    <publishedDate>2011-03-15</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Gas Network Topology Optimization for Upcoming Market Requirements</title>
    <abstract language="eng">Gas distribution networks are complex structures that consist of&#13;
passive pipes, and active, controllable elements such as valves and&#13;
compressors. Controlling such network means to find a suitable setting&#13;
for all active components such that a nominated amount of gas can be&#13;
transmitted from entries to exits through the network, without&#13;
violating physical or operational constraints. The control of a&#13;
large-scale gas network is a challenging task from a practical point&#13;
of view. In most companies the actual controlling process is supported&#13;
by means of computer software that is able to simulate the flow of the&#13;
gas. However, the active settings have to be set manually within such&#13;
simulation software. The solution quality thus depends on the&#13;
experience of a human planner.&#13;
&#13;
When the gas network is insufficient for the transport then topology&#13;
extensions come into play. Here a set of new pipes or active elements&#13;
is determined such that the extended network admits a feasible control&#13;
again. The question again is how to select these extensions and where&#13;
to place them such that the total extension costs are&#13;
minimal. Industrial practice is again to use the same simulation&#13;
software, determine extensions by experience, add them to the virtual&#13;
network, and then try to find a feasible control of the active&#13;
elements. The validity of this approach now depends even more on the&#13;
human planner.&#13;
&#13;
Another weakness of this manual simulation-based approach is that it&#13;
cannot establish infeasibility of a certain gas nomination, unless all&#13;
settings of the active elements are tried. Moreover, it is impossible&#13;
to find a cost-optimal network extension in this way.&#13;
In order to overcome these shortcomings of the manual planning&#13;
approach we present a new approach, rigorously based on mathematical&#13;
optimization. Hereto we describe a model for finding feasible&#13;
controls and then extend this model such that topology extensions can&#13;
additionally and simultaneously be covered. Numerical results for real-world instances are presented and&#13;
discussed.</abstract>
    <identifier type="serial">11-09</identifier>
    <identifier type="urn">urn:nbn:de:0297-zib-12348</identifier>
    <identifier type="doi">10.1109/EEM.2011.5953035</identifier>
    <enrichment key="SourceTitle">Appeared in: Engery Market (EEM), 2011 8th International Conference on the European, Zagreb, 25-27 May 2011, pp. 346-351</enrichment>
    <author>Armin Fügenschuh</author>
    <submitter>-empty- (Opus4 user: )</submitter>
    <author>Benjamin Hiller</author>
    <submitter>Jonas Schweiger</submitter>
    <author>Jesco Humpola</author>
    <author>Thorsten Koch</author>
    <author>Thomas Lehmann</author>
    <author>Robert Schwarz</author>
    <author>Jonas Schweiger</author>
    <author>Jácint Szabó</author>
    <series>
      <title>ZIB-Report</title>
      <number>11-09</number>
    </series>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Mathematical Optimization</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Gas Distribution Networks</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Topology Planning</value>
    </subject>
    <collection role="msc" number="76N25">Flow control and optimization</collection>
    <collection role="msc" number="90B10">Network models, deterministic</collection>
    <collection role="msc" number="90C11">Mixed integer programming</collection>
    <collection role="msc" number="90C30">Nonlinear programming</collection>
    <collection role="institutes" number="optimization">Mathematical Optimization</collection>
    <collection role="persons" number="fuegenschuh">Fügenschuh, Armin</collection>
    <collection role="persons" number="koch">Koch, Thorsten</collection>
    <collection role="projects" number="MODAL-GasLab">MODAL-GasLab</collection>
    <collection role="projects" number="ForNe">ForNe</collection>
    <collection role="projects" number="MODAL-Gesamt">MODAL-Gesamt</collection>
    <collection role="persons" number="schweiger">Schweiger, Jonas</collection>
    <collection role="institutes" number="aopt">Applied Optimization</collection>
    <file>https://opus4.kobv.de/opus4-zib/files/1234/ZR-11-09.pdf</file>
  </doc>
  <doc>
    <id>3338</id>
    <completedYear>2009</completedYear>
    <publishedYear>2009</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>430</pageFirst>
    <pageLast>441</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>article</type>
    <publisherName>Springer</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Latent Dirichlet Allocation for Automatic Document Categorization</title>
    <parentTitle language="eng">Machine Learning and Knowledge Discovery in Databases</parentTitle>
    <enrichment key="PeerReviewed">yes</enrichment>
    <author>István Bíró</author>
    <author>Jácint Szabó</author>
    <collection role="institutes" number="optimization">Mathematical Optimization</collection>
    <collection role="institutes" number="aopt">Applied Optimization</collection>
  </doc>
  <doc>
    <id>3343</id>
    <completedYear>2007</completedYear>
    <publishedYear>2007</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>167</pageFirst>
    <pageLast>181</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>article</type>
    <publisherName>Springer</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Matching problems in polymatroids without double circuits</title>
    <parentTitle language="eng">Integer Programming and Combinatorial Optimization</parentTitle>
    <author>M. Makai</author>
    <author>G. Pap</author>
    <author>Jácint Szabó</author>
    <collection role="institutes" number="optimization">Mathematical Optimization</collection>
    <collection role="institutes" number="aopt">Applied Optimization</collection>
  </doc>
  <doc>
    <id>3342</id>
    <completedYear>2009</completedYear>
    <publishedYear>2009</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>619</pageFirst>
    <pageLast>628</pageLast>
    <pageNumber/>
    <edition/>
    <issue>5</issue>
    <volume>29</volume>
    <type>article</type>
    <publisherName>Springer</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">A note on parity constrained orientations</title>
    <parentTitle language="eng">Combinatorica</parentTitle>
    <enrichment key="PeerReviewed">yes</enrichment>
    <author>T. Király</author>
    <author>Jácint Szabó</author>
    <collection role="institutes" number="optimization">Mathematical Optimization</collection>
    <collection role="institutes" number="aopt">Applied Optimization</collection>
  </doc>
  <doc>
    <id>3340</id>
    <completedYear>2007</completedYear>
    <publishedYear>2007</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>347</pageFirst>
    <pageLast>354</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>article</type>
    <publisherName>Springer</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">On the generalization of the matroid parity problem</title>
    <parentTitle language="eng">Graph Theory in Paris</parentTitle>
    <author>A. Recski</author>
    <author>Jácint Szabó</author>
    <collection role="institutes" number="optimization">Mathematical Optimization</collection>
    <collection role="institutes" number="aopt">Applied Optimization</collection>
  </doc>
  <doc>
    <id>3351</id>
    <completedYear>2006</completedYear>
    <publishedYear>2006</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>267</pageFirst>
    <pageLast>293</pageLast>
    <pageNumber/>
    <edition/>
    <issue>4</issue>
    <volume>52</volume>
    <type>article</type>
    <publisherName>John Wiley &amp; Sons</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">The k-piece packing problem</title>
    <parentTitle language="eng">Journal of Graph Theory</parentTitle>
    <author>D. Hartvigsen</author>
    <author>P. Hell</author>
    <author>Jácint Szabó</author>
    <collection role="institutes" number="optimization">Mathematical Optimization</collection>
    <collection role="institutes" number="aopt">Applied Optimization</collection>
  </doc>
  <doc>
    <id>3350</id>
    <completedYear>2010</completedYear>
    <publishedYear>2010</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>article</type>
    <publisherName>Elsevier BV</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Upgrading edge-disjoint paths in a ring</title>
    <parentTitle language="eng">Discrete Optimization</parentTitle>
    <enrichment key="PeerReviewed">yes</enrichment>
    <author>Jácint Szabó</author>
    <collection role="institutes" number="optimization">Mathematical Optimization</collection>
    <collection role="institutes" number="aopt">Applied Optimization</collection>
  </doc>
  <doc>
    <id>3341</id>
    <completedYear>2008</completedYear>
    <publishedYear>2008</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>854</pageFirst>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>22</volume>
    <type>article</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Matroid parity and jump systems</title>
    <parentTitle language="eng">SIAM Journal on Discrete Mathematics</parentTitle>
    <author>Jácint Szabó</author>
    <collection role="institutes" number="optimization">Mathematical Optimization</collection>
    <collection role="institutes" number="aopt">Applied Optimization</collection>
  </doc>
  <doc>
    <id>3348</id>
    <completedYear>2005</completedYear>
    <publishedYear>2005</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>1</pageFirst>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>12</volume>
    <type>article</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">A Gallai-Edmonds type theorem for the k-piece packing problem</title>
    <parentTitle language="eng">Electron. J. Combin</parentTitle>
    <author>M. Janata</author>
    <author>M. Loebl</author>
    <author>Jácint Szabó</author>
    <collection role="institutes" number="optimization">Mathematical Optimization</collection>
    <collection role="institutes" number="aopt">Applied Optimization</collection>
  </doc>
  <doc>
    <id>3347</id>
    <completedYear>2009</completedYear>
    <publishedYear>2009</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>436</pageFirst>
    <pageLast>446</pageLast>
    <pageNumber/>
    <edition/>
    <issue>2</issue>
    <volume>99</volume>
    <type>article</type>
    <publisherName>Elsevier</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Good characterizations for some degree constrained subgraphs</title>
    <parentTitle language="eng">Journal of Combinatorial Theory, Series B</parentTitle>
    <enrichment key="PeerReviewed">yes</enrichment>
    <author>Jácint Szabó</author>
    <collection role="institutes" number="optimization">Mathematical Optimization</collection>
    <collection role="institutes" number="aopt">Applied Optimization</collection>
  </doc>
  <doc>
    <id>3344</id>
    <completedYear>2008</completedYear>
    <publishedYear>2008</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>679</pageFirst>
    <pageLast>692</pageLast>
    <pageNumber/>
    <edition/>
    <issue>6</issue>
    <volume>28</volume>
    <type>article</type>
    <publisherName>Springer</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">The parity problem of polymatroids without double circuits</title>
    <parentTitle language="eng">Combinatorica</parentTitle>
    <author>M. Makai</author>
    <author>Jácint Szabó</author>
    <collection role="institutes" number="optimization">Mathematical Optimization</collection>
    <collection role="institutes" number="aopt">Applied Optimization</collection>
  </doc>
  <doc>
    <id>3346</id>
    <completedYear>2010</completedYear>
    <publishedYear>2010</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>243</pageFirst>
    <pageLast>257</pageLast>
    <pageNumber/>
    <edition/>
    <issue>2</issue>
    <volume>26</volume>
    <type>article</type>
    <publisherName>Springer</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Induced graph packing problems</title>
    <parentTitle language="eng">Graphs and Combinatorics</parentTitle>
    <enrichment key="PeerReviewed">yes</enrichment>
    <author>Z. Király</author>
    <author>Jácint Szabó</author>
    <collection role="institutes" number="optimization">Mathematical Optimization</collection>
    <collection role="institutes" number="aopt">Applied Optimization</collection>
  </doc>
  <doc>
    <id>3349</id>
    <completedYear>2009</completedYear>
    <publishedYear>2009</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>27</pageFirst>
    <pageLast>48</pageLast>
    <pageNumber/>
    <edition/>
    <issue>1</issue>
    <volume>29</volume>
    <type>article</type>
    <publisherName>Springer</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">The superstar packing problem</title>
    <parentTitle language="eng">Combinatorica</parentTitle>
    <enrichment key="PeerReviewed">yes</enrichment>
    <author>M. Janata</author>
    <author>Jácint Szabó</author>
    <collection role="institutes" number="optimization">Mathematical Optimization</collection>
    <collection role="institutes" number="aopt">Applied Optimization</collection>
  </doc>
  <doc>
    <id>3345</id>
    <completedYear>2008</completedYear>
    <publishedYear>2008</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>485</pageFirst>
    <pageLast>494</pageLast>
    <pageNumber/>
    <edition/>
    <issue>5</issue>
    <volume>24</volume>
    <type>article</type>
    <publisherName>Springer</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Packing Trees with Constraints on the Leaf Degree</title>
    <parentTitle language="eng">Graphs and Combinatorics</parentTitle>
    <author>Jácint Szabó</author>
    <collection role="institutes" number="optimization">Mathematical Optimization</collection>
    <collection role="institutes" number="aopt">Applied Optimization</collection>
  </doc>
  <doc>
    <id>1515</id>
    <completedYear/>
    <publishedYear/>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>reportzib</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2012-04-24</completedDate>
    <publishedDate>2012-04-24</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">The set of solutions to nomination validation in passive gas   transportation networks with a generalized flow formula</title>
    <abstract language="eng">In this paper we give an analytical description on the structure of&#13;
  solutions to the gas nomination validation problem in gas&#13;
  transportation networks. These networks are assumed to contain no&#13;
  active devices, only certain hypothetical pipelines, where the flow&#13;
  of gas is modeled by a generalized version of the quadratic&#13;
  Weymouth's equation. The purpose of considering generalized flow&#13;
  formulas is to be able to adapt our results to various gas network&#13;
  optimization problems involving gas flow formulas beyond Weymouth's&#13;
  equation. Such formulas can appear in leaves of branch and bound&#13;
  trees, or they can stem from discretization and linearization&#13;
  carried out at active devices. We call a balanced supply-demand&#13;
  vector a nomination, and the passive nomination validation problem&#13;
  is to decide whether there exist pressures at the nodes generating a&#13;
  given nomination. We prove that in our setup the pressure square&#13;
  vectors generating a given nomination form a one-dimensional&#13;
  connected and continuous curve in the pressure square space, and&#13;
  this curve is a line for the classical Weymouth's equation.  We also&#13;
  present a visual approach for the easy comprehension of how this&#13;
  solution curve arises; we give a short investigation of the set of&#13;
  feasible nominations; and finally we give a proof that the&#13;
  nomination validation problem in gas networks with active devices is&#13;
  NP-complete.</abstract>
    <identifier type="issn">1438-0064</identifier>
    <identifier type="urn">urn:nbn:de:0297-zib-15151</identifier>
    <author>Jácint Szabó</author>
    <submitter>Benjamin Hiller</submitter>
    <series>
      <title>ZIB-Report</title>
      <number>11-44</number>
    </series>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>pressure drop equation</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>gas networks</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>generalized flow formula</value>
    </subject>
    <collection role="ccs" number="G.">Mathematics of Computing</collection>
    <collection role="msc" number="90-XX">OPERATIONS RESEARCH, MATHEMATICAL PROGRAMMING</collection>
    <collection role="institutes" number="optimization">Mathematical Optimization</collection>
    <collection role="projects" number="MODAL-GasLab">MODAL-GasLab</collection>
    <collection role="projects" number="ForNe">ForNe</collection>
    <collection role="projects" number="MODAL-Gesamt">MODAL-Gesamt</collection>
    <collection role="institutes" number="aopt">Applied Optimization</collection>
    <file>https://opus4.kobv.de/opus4-zib/files/1515/ZR-11-44.pdf</file>
  </doc>
</export-example>
