[904] | 1 | <!-- ******************************************************** --> |
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| 2 | <!-- Docbook Version: For Toolkit Developers Guide --> |
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| 3 | <!-- ******************************************************** --> |
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| 4 | |
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| 5 | <!-- ******************* Section (Level#1) ****************** --> |
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| 6 | <sect1 id="sect.DsgnFuncHitDig"> |
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| 7 | <title> |
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| 8 | Hits and Digitization |
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| 9 | </title> |
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| 10 | |
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| 11 | |
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| 12 | <!-- ******************* Section (Level#2) ****************** --> |
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| 13 | <sect2 id="sect.DsgnFuncHitDig.DsgPhlsp"> |
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| 14 | <title> |
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| 15 | Design Philosophy |
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| 16 | </title> |
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| 17 | |
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| 18 | <para> |
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| 19 | In Geant4 a <emphasis role="italic">hit</emphasis> is a snapshot of a |
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| 20 | physical interaction or an accumulation of interactions of a track or |
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| 21 | tracks in a ``sensitive'' detector component. A digitization, or |
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| 22 | <emphasis role="italic">digit</emphasis>, represents a detector output, |
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| 23 | such as an ADC/TDC count or a trigger signal. |
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| 24 | A <emphasis role="italic">digit</emphasis> is created from one or |
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| 25 | more hits and/or other <emphasis role="italic">digits</emphasis>. |
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| 26 | </para> |
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| 27 | |
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| 28 | <para> |
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| 29 | Given the wide variety of Geant4 applications, ways of describing detector |
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| 30 | sensitivity and the quantities to be stored in the |
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| 31 | <emphasis role="italic">hits</emphasis> and |
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| 32 | <emphasis role="italic">digits</emphasis> vary greatly. This category |
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| 33 | therefore provides only abstract classes for both detector sensitivity and |
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| 34 | <emphasis role="italic">hits</emphasis>/<emphasis role="italic">digits</emphasis>. |
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| 35 | It also provides tools for organizing the |
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| 36 | <emphasis role="italic">hits</emphasis>/<emphasis role="italic">digits</emphasis> |
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| 37 | into collections. |
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| 38 | </para> |
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| 39 | |
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| 40 | </sect2> |
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| 41 | |
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| 42 | <!-- ******************* Section (Level#2) ****************** --> |
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| 43 | <sect2 id="sect.DsgnFuncHitDig.ClassDsg"> |
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| 44 | <title> |
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| 45 | Class Design |
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| 46 | </title> |
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| 47 | |
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| 48 | <para> |
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| 49 | <itemizedlist spacing="compact"> |
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| 50 | <listitem><para> |
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| 51 | <emphasis role="bold">G4SensitiveDetectorManager</emphasis> - |
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| 52 | a list of G4SensitiveDetectors. |
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| 53 | </para></listitem> |
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| 54 | <listitem><para> |
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| 55 | <emphasis role="bold">G4HitsStructure</emphasis> - |
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| 56 | a tree-like structure of G4Hit collections. Each branch represents the |
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| 57 | hits in given sub-detector. For example, the first level of branches |
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| 58 | may consist of a tracker, ECAL, and HCAL, while the second level, in HCAL, |
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| 59 | consists of the barrel and endcaps. Finally the barrel may have phi-slices, |
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| 60 | Z-slices, etc. |
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| 61 | </para></listitem> |
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| 62 | <listitem><para> |
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| 63 | <emphasis role="bold">G4VSensitiveDetector</emphasis> - |
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| 64 | an abstract class of all of sensitive volumes. |
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| 65 | </para></listitem> |
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| 66 | <listitem><para> |
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| 67 | <emphasis role="bold">G4HitsCollection</emphasis> - |
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| 68 | a collection of hits. Instantiates an RWCollection class. |
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| 69 | </para></listitem> |
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| 70 | <listitem><para> |
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| 71 | <emphasis role="bold">G4VHit</emphasis> - |
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| 72 | this class has all the information about a particular hit caused by a |
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| 73 | single step. |
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| 74 | </para></listitem> |
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| 75 | <listitem><para> |
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| 76 | <emphasis role="bold">G4VDigitizer</emphasis> - |
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| 77 | the class of objects which transform the hits deposited by particles into |
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| 78 | digitizations. |
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| 79 | </para></listitem> |
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| 80 | <listitem><para> |
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| 81 | <emphasis role="bold">G4DigitizerManager</emphasis> - |
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| 82 | the (single) object dispatching common messages to individual digitizers. |
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| 83 | </para></listitem> |
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| 84 | <listitem><para> |
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| 85 | <emphasis role="bold">G4VDigi</emphasis> - |
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| 86 | an abstract (base) class for all G4 digitizations. This could be data as |
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| 87 | simple as a singe byte, or as complex as an Ntuple. |
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| 88 | </para></listitem> |
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| 89 | <listitem><para> |
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| 90 | <emphasis role="bold">G4DigiStructure</emphasis> - |
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| 91 | digitizations are organized as a structure, which could be anything |
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| 92 | between a single value and an Ntuple. |
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| 93 | </para></listitem> |
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| 94 | </itemizedlist> |
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| 95 | </para> |
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| 96 | |
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| 97 | <para> |
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| 98 | The object-oriented design of the 'hit' related classes is shown in the |
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| 99 | following class diagrams. The diagrams are described in the Booch notation. |
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| 100 | <xref linkend="fig.DsgnFuncHitDig_1" /> shows the general management of hit classes. |
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| 101 | <xref linkend="fig.DsgnFuncHitDig_2" /> shows the OO design of user-related hit classes. |
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| 102 | <xref linkend="fig.DsgnFuncHitDig_3" /> shows the OO design of the readout geometry. |
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| 103 | |
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| 104 | <figure id="fig.DsgnFuncHitDig_1"> |
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| 105 | <title> |
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| 106 | Overview of hit classes management |
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| 107 | </title> |
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| 108 | <mediaobject> |
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| 109 | <imageobject role="fo"> |
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| 110 | <imagedata |
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[921] | 111 | fileref="./AllResources/OOAnalysisDesign/Hit/classDgmHitMain.jpg" format="JPG" contentwidth="10.0cm" align="center" /> |
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[904] | 112 | </imageobject> |
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| 113 | <imageobject role="html"> |
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[1208] | 114 | <imagedata fileref="./AllResources/OOAnalysisDesign/Hit/classDgmHitMain.jpg" format="JPG" contentwidth="120%" align="center" /> |
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[904] | 115 | </imageobject> |
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| 116 | </mediaobject> |
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| 117 | </figure> |
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| 118 | |
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| 119 | |
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| 120 | <figure id="fig.DsgnFuncHitDig_2"> |
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| 121 | <title> |
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| 122 | User hit classes |
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| 123 | </title> |
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| 124 | <mediaobject> |
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| 125 | <imageobject role="fo"> |
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| 126 | <imagedata |
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[921] | 127 | fileref="./AllResources/OOAnalysisDesign/Hit/classDgmHitUser.jpg" format="JPG" |
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[904] | 128 | contentwidth="10.0cm" align="center" /> |
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| 129 | </imageobject> |
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| 130 | <imageobject role="html"> |
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[1208] | 131 | <imagedata fileref="./AllResources/OOAnalysisDesign/Hit/classDgmHitUser.jpg" format="JPG" contentwidth="120%" align="center" /> |
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[904] | 132 | </imageobject> |
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| 133 | </mediaobject> |
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| 134 | </figure> |
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| 135 | |
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| 136 | <figure id="fig.DsgnFuncHitDig_3"> |
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| 137 | <title> |
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| 138 | Readout geometry |
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| 139 | </title> |
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| 140 | <mediaobject> |
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| 141 | <imageobject role="fo"> |
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[921] | 142 | <imagedata fileref="./AllResources/OOAnalysisDesign/Hit/classDgmReadoutGeom.jpg" format="JPG" contentwidth="10.0cm" align="center" /> |
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[904] | 143 | </imageobject> |
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| 144 | <imageobject role="html"> |
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[1208] | 145 | <imagedata fileref="./AllResources/OOAnalysisDesign/Hit/classDgmReadoutGeom.jpg" format="JPG" contentwidth="120%" align="center" /> |
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[904] | 146 | </imageobject> |
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| 147 | </mediaobject> |
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| 148 | </figure> |
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| 149 | </para> |
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| 150 | |
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| 151 | <!-- ******* Bridgehead ******* --> |
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| 152 | <bridgehead role="revisionHistory" renderas="sect4"> |
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| 153 | [Status of this chapter] |
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| 154 | </bridgehead> |
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| 155 | <para> |
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| 156 | <simplelist type="var"> |
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| 157 | <member> |
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| 158 | 27.06.05 section on design philosophy added (from Geant4 general paper) by |
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| 159 | D.H. Wright |
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| 160 | </member> |
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| 161 | <member> |
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| 162 | Dec. 2006 Conversion from latex to Docbook verson by K. Amako |
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| 163 | </member> |
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| 164 | </simplelist> |
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| 165 | </para> |
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| 166 | |
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| 167 | |
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| 168 | |
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| 169 | </sect2> |
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[1208] | 170 | </sect1> |
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