Applying Constraint Reasoning to Real-world Distributed Task ...

isi.edu

Applying Constraint Reasoning to Real-world Distributed Task ...

×ØÓÖ�× Ú�Ö���Ð� Ú�ÐÙ� �Ò�ÓÖÑ�Ø�ÓÒ ��ÓÙØ ÓÒÒ� Ø�� Ú�Ö���Ð�×

Ö�Ø��Ö Ø��Ò �Ù�Ð��Ò� � ÓÑÔÐ�Ø� Ô�Ø� �ÖÓÑ ÖÓÓØ ØÓ Ð��� �Ò�

���ÒØ× �Ö� ��Ð� ØÓ ×��Ö � �ÓÖ ×ÓÐÙØ�ÓÒ× �×ÝÒ �ÖÓÒÓÙ×ÐÝ

Ï��Ò Ø�Ñ� �× Ð�Ñ�Ø�� Û� �Ò �Ò Ö��×� Ø�� Ú�ÐÙ� Ó� Ø��

� Ô�Ö�Ñ�Ø�Ö Û�� � �Ò ØÙÖÒ �ÐÐÓÛ× ���ÒØ× ØÓ ��ÒÓÖ� ×Ñ�ÐÐ�Ö

Ó×Ø× �Ý ÒÓØ Ö�ÔÓÖØ�Ò� ØÓ �����Ö ÔÖ�ÓÖ�ØÝ ���ÒØ× �ÐØ�ÓÙ��

Ø��× ��Ú�× ÙÔ ÓÔØ�Ñ�Ð�ØÝ �ÙÖ�ÒØ��× �Ø ÔÖ�Ú�ÒØ× �����Ö ÔÖ�ÓÖ�ØÝ

���ÒØ× �ÖÓÑ ×Û�Ø ��Ò� Ø���Ö Ú�ÐÙ�× Ø�Ù× �ÐÐÓÛ�Ò� Ø�� ×Ý×Ø�Ñ

ØÓ Ö�� � � ×Ø��Ð� ×Ø�Ø� ÑÓÖ� ÕÙ� �ÐÝ ���Ý ÔÖÓÔ�ÖØÝ Ó� Ø��×

ÐÓ �Ð ØÓÐ�Ö�Ò � �× Ø��Ø ���ÒØ× ×Ø�ÐÐ �ØØ�ÑÔØ ØÓ ¬Ò� Ú�ÐÙ�× Ø��Ø

Ñ�Ò�Ñ�Þ� Ó×Ø× �× ÐÓÒ� �× �Ø �Ò �� �ÓÒ� ÐÓ �ÐÐÝ Û�Ø�ÓÙØ

�� �ØÖ� ��Ò� ÁÒ ��Ò�Ö�Ð Ø�� � Ô�Ö�Ñ�Ø�Ö ÛÓÙÐ� Ò��� ØÓ ��

�Ò��Ò��Ö�� Ù×�Ò� �ÓÑ��Ò �ÒÓÛÐ���� �ÙØ ÓÙÖ ÔÓ�ÒØ �× Ø��Ø

��ÓÔØ �× �ØÙÒ� ��Ð�� �Ò Ø��× Û�Ý

4. DEALING WITH UNCERTAINTY AND

DYNAMICS IN ADOPT-SC

ÁÒ Ø��× ×� Ø�ÓÒ Û�Ð�Ý ÓÙØ Ø�� ��Ø��Ð× Ó� Ø�� Ù×� Ó� �Ò ÙÒ��Ö

ÐÝ�Ò� ÔÖÓ����Ð�ØÝ ��×ØÖ��ÙØ�ÓÒ �ÓÖ ��ÓÔØ Ë� �Ò� �Ø× �ÒØ��Ö�

Ø�ÓÒ �ÒØÓ Ø�� ÛÓÖ��Ò�× Ó� Ø�� Ö�×ÓÙÖ � �ÐÐÓ �Ø�ÓÒ �Ð�ÓÖ�Ø�Ñ

�ÓÖ �� � Ø�×� �Ò Ì� � Ø�×� ×Ø�ØÙ× �ÖÓÑ �È� ÆÈ� Í� Ö�Ô

Ö�×�ÒØ�Ò� ÔÖ�×�ÒØ ÒÓØ ÔÖ�×�ÒØ �Ò� ÙÒ�ÒÓÛÒ Ö�×Ô� Ø�Ú�ÐÝ �×

Ñ��ÒØ��Ò�� Ì�� ×�Ø Ó� Ø�×� ×Ø�ØÙ× �ÓÖ Ì��× �ÐÐ�� Ø�� Ø�×�

×Ø�ØÙ× Ú� ØÓÖ ��ÒÓØ�� Î �Ò �ÓÖ ���ÒØ �Ò Ì�� Ø�×� ×Ø�ØÙ× �×

Ù×�� �Ý ��ÓÔØ Ë� ØÓ �� ��� Û�� �Ú�Ö���Ð� Ú�ÐÙ�× ØÓ �××��Ò

Ì�×�× Û�� � Ñ�Ô ØÓ Ú�Ö���Ð�× Û�Ø� ×Ø�ØÙ× È ÓÙÐ� �� �×

×��Ò�� ��Ø��Ö Ú�ÐÙ� �ÐÐÓ �Ø�� ÓÖ Á�ÒÓÖ�� Ì�×�× Û�Ø� ×Ø�ØÙ×

ÆÈ ÑÙ×Ø �� �××��Ò�� Ø�� Ú�ÐÙ� ÆÓØÈ Ö�×�ÒØ ��Ò�ÐÐÝ Ø�×�×

Û�Ø� ×Ø�ØÙ× Í �Ò �� �××��Ò�� �ÒÝ Ú�ÐÙ� ��Ô�Ò��Ò� ÓÒ Ø��

Ú�ÐÙ� �Ø ÓØ��Ö ���ÒØ× � Ø�×� ×Ø�ØÙ× Ú� ØÓÖ ÔÖÓ�� Ø�ÓÒ �× Ø��

×�Ø Ó� Ø�×�× �Ò Î �Ò Û��Ö� Ø�� Ú�ÐÙ� �× Ó� � �ÖØ��Ò ØÝÔ� � �

Ø�� ×�Ø Î �Ò

Í �× Ø�Ó×� Ø�×�× �ÓÖ Û�� � �Ò ��× Ø�� Ú�ÐÙ� Í

��Ñ Ó� Ø�� ÙÒ �ÖØ��ÒØÝ Ö��×ÓÒ�Ò� �× ØÓ Ñ��� Î

��

�Ò

È � ÌÔ � �

ØÓ Ñ��� Ø�� Ø�×�× Ø�� ���ÒØ Ø��Ò�× �Ö� ÔÖ�×�ÒØ �� Ø�� ×�Ñ�

�× Ø�� Ø�×�× Ø��Ø �Ö� � ØÙ�ÐÐÝ ÔÖ�×�ÒØ

�ÓÖ �� � Ì �ÐÐØ�×�× Ø�� ÔÖÓ����Ð�ØÝ Ø��Ø Ø�� Ø�×� �×

ÙÖÖ�ÒØÐÝ ÔÖ�×�ÒØ �×ÈÖ Ì Ì�� ���ÒØ Ñ��ÒØ��Ò× Ø��× ÔÖÓ�

���Ð�ØÝ �ÓÖ �� � Ø�×� � � �Ø Ñ��ÒØ��Ò× ÔÖÓ����Ð�Ø��× ÈÊ �

�ÈÖ Ì ���ÈÖ ÌÆ � �� � ���ÒØ × ÔÖÓ����Ð�ØÝ ��×ØÖ��ÙØ�ÓÒ

�× Ñ��ÒØ��Ò�� ÐÓ �ÐÐÝ ��Ò � ���ÒØ× Ñ�Ý ��Ú� ��«�Ö�ÒØ Ú��Û×

ÓÒ Û�� � Ø�×�× �Ö� ÔÖ�×�ÒØ � �ÙÒ Ø�ÓÒ Ñ�Ô× ÈÊ ØÓ Î �Ò

Ì�� ��Ø��Ð× Ó� Ø��× Ñ�ÔÔ�Ò� �Ö� ×ÓÑ�Û��Ø �Ö��ØÖ�ÖÝ �Ò�

Ò��� ØÓ �Ó×�Ò �Ò � �ÓÑ��Ò ��Ô�Ò��ÒØ Ñ�ÒÒ�Ö ÁÒ Ø�� ×�Ò

×ÓÖ Ò�ØÛÓÖ� �ÓÑ��Ò Û� Ù×� Ø�� �ÓÐÐÓÛ�Ò� Ñ�ÔÔ�Ò��

�� ÈÖ Ì � � Ø��Ò ÆÈ

�Ð×� �� ÈÖ Ì � �� Ø��Ò È

�Ð×� Í

4.1 Algorithm

Ì�� ÐÓÛ Ð�Ú�Ð ÔÖÓ����Ð�×Ø� ÓÑÔÓÒ�ÒØ �Ò� ��ÓÔØ Ë� ×

Ø�×� �ÐÐÓ �Ø�ÓÒ �Ð�ÓÖ�Ø�Ñ ÖÙÒ �×ÝÒ �ÖÓÒÓÙ×ÐÝ ��ÖÐ��Ö Û�

��× Ö���� Ø�� ÛÓÖ��Ò�× Ó� Ø�� Ø�×� �ÐÐÓ �Ø�ÓÒ �Ð�ÓÖ�Ø�Ñ �Ò

Ø��× ×� Ø�ÓÒ Û� ��× Ö��� Ø�� �Ð�ÓÖ�Ø�Ñ× ÓÔ�Ö�Ø�Ò� ÓÒ Ø��

ÔÖÓ����Ð�×Ø� Ö�ÔÖ�×�ÒØ�Ø�ÓÒ �Ò� ��× Ö��� �ÓÛ Ø��Ý �Ö� �Ò

Ø��Ö�Ø�� Û�Ø� ��ÓÔØ Ë�

Ì�� �ÒØ�Ö�� � ��ØÛ��Ò Ø�� ÔÖÓ����Ð�×Ø� Ö�ÔÖ�×�ÒØ�Ø�ÓÒ �Ò�

��ÓÔØ Ë� �× �ÒØ�ÒØ�ÓÒ�ÐÐÝ ��ÔØ ×�ÑÔÐ� ×Ó Ø��Ø ��Ò��× ØÓ ��

Ø��Ö ÓÑÔÓÒ�ÒØ �Ó ÒÓØ Ö�ÕÙ�Ö� ×��Ò�¬ �ÒØ ��Ò��× �Ò Ø��

ÓØ��Ö ÁÒ�ÓÖÑ�Ø�ÓÒ ­ÓÛ× �ÖÓÑ Ø�� ÔÖÓ����Ð�×Ø� Ö�ÔÖ�×�ÒØ�

Ø�ÓÒ ØÓ ��ÓÔØ Ë� Ú�� Ñ�××���× �Ò�� �Ø�Ò� Ø��Ø Ø�� ×Ø�ØÙ× Ó�

� Ø�×� ��× ��Ò��� �ÓÖ �Ü�ÑÔÐ� � Ñ�××��� �× ×�ÒØ Û��Ò

Ø�� ×Ø�ØÙ× Ó� � Ø�×� ��Ò��× �ÖÓÑ Í ØÓ È ÁÒ Ø�� ÓØ��Ö

��Ö� Ø�ÓÒ ��ÓÔØ Ë� ×�Ò�× Ñ�××���× �Ò�� �Ø�Ò� Û�� � Ø�×�×

ÓØ��Ö ���ÒØ× ��Ð��Ú� ØÓ �� ÔÖ�×�ÒØ Û��Ò�Ú�Ö �Ø Ö� ��Ú�× �

ÓÑÑÙÒ� �Ø�ÓÒ ÔÖÓÚ���Ò� Ø��Ø �Ò�ÓÖÑ�Ø�ÓÒ �ÓÖ �Ü�ÑÔÐ� ��

���ÒØ ÓÑÑÙÒ� �Ø�× Ø�� ÔÖ�×�Ò � Ó� Ì�×� ØÓ ���ÒØ

��ÓÔØ Ë� �Ø ���ÒØ Û�ÐÐ ×�Ò� � Ñ�××��� ØÓ Ø�� ÔÖÓ����Ð�×Ø�

ÓÑÔÓÒ�ÒØ �Ò�� �Ø�Ò� Ø�� ÔÖ�×�Ò � Ó� Ì�×� ÆÓØ� � Ø��Ø

��ÓÔØ Ë� ×�Ò�× Ø��× Ñ�××��� Ö���Ö�Ð�×× Ó� �Ø× ��Ð���× ��ÓÙØ

Ø�� Ø�×� ×�Ò � Ø�� ÔÖÓ����Ð�×Ø� ÓÑÔÓÒ�ÒØ �Ò Ù×� Ø�� �Ò

�ÓÖÑ�Ø�ÓÒ ØÓ ��Ò�� �Ø× ÔÖÓ����Ð�ØÝ ��×ØÖ��ÙØ�ÓÒ Ö��Ò�ÓÖ �Ò�

ÓÖ Ð�××�Ò�Ò� Ø�� ÔÖÓ����Ð�ØÝ � Ø�×� �× ÔÖ�×�ÒØ

Ì�� ÔÖÓ����Ð�×Ø� ÓÑÔÓÒ�ÒØ ��× ØÛÓ ��×Ø�Ò Ø ÑÓ��× Ó�

ÓÔ�Ö�Ø�ÓÒ Ï�� � ÑÓ�� Ó� ÓÔ�Ö�Ø�ÓÒ ØÓ Ù×� �× ��Ø�ÖÑ�Ò��

�Ý Û��Ø��Ö ��ÓÔØ Ë� ��× �ÐÐÓ �Ø�� Ø�� ���ÒØ ØÓ � Ø�×� Ø��Ø

�× ÙÖÖ�ÒØÐÝ ÔÖ�×�ÒØ ÁÒ Ø�� ×�Ò×ÓÖ Ò�ØÛÓÖ� �ÓÑ��Ò Ø��× �Ò

�� ��Ø�ÖÑ�Ò�� �Ý Û��Ø��Ö ��ÓÔØ Ë� ��× ×Ô� �¬�� Ù×�Ò� �

Ö���Ö ���� Ø��Ø �Ò ��Ø� Ø � Ø�Ö��Ø Á� ��ÓÔØ Ë� ��× �Ð

ÐÓ �Ø�� Ö�×ÓÙÖ �× Ó� Ø�� ���ÒØ ØÓ � ÔÖ�×�ÒØ Ø�×� Ø��Ò Ø��

ÔÖÓ����Ð�×Ø� ÓÑÔÓÒ�ÒØ ��× � Ô�××�Ú� ÑÓÒ�ØÓÖ�Ò� ÖÓÐ� Á�

��ÓÔØ Ë� �ÐÐÓ �Ø�× Ø�� ���ÒØ ØÓ � Ø�×� Ø��Ø �× ÒÓØ ÔÖ�×�ÒØ

Ø��Ò Ø�� ÔÖÓ����Ð�×Ø� ÓÑÔÓÒ�ÒØ � Ø× ÔÖÓ � Ø�Ú�ÐÝ ØÓ ��Ø�Ö

Ñ�Ò� Û�� � Ø�×�× �Ö� ÔÖ�×�ÒØ ÁÒ ÓØ��Ö ÛÓÖ�× Ø�� ÔÖÓ����Ð�×

Ø� ÓÑÔÓÒ�ÒØ �× ÓÒÐÝ ÔÖÓ � Ø�Ú� Û��Ò ��ÓÔØ Ë� �× ���Ð�Ò�

��ÓÔØ Ë� �× ��Ú�Ò Ö�×ÔÓÒ×���Ð�ØÝ �ÓÖ Ñ���Ò� �� �×�ÓÒ× �� �Ø

�Ò �� �Ù×� �Ø �× ��Ð� ØÓ Ñ��� �ÐÓ��ÐÐÝ ÓÔØ�Ñ�Ð �ÐÐÓ �Ø�ÓÒ

�� �×�ÓÒ× Û��Ð� Ø�� ÔÖÓ����Ð�×Ø� ÓÑÔÓÒ�ÒØ �Ò ÓÒÐÝ Ö�Ò

�ÓÑÐÝ �ÓÓ×� ��ØÛ��Ò ��Ø� Ø�� Ø�Ö��Ø× Ï��Ò ��ÓÔØ Ë� �×

���Ð�Ò� � � �Ø �× �×��Ò� �ÓÖ � Ø�ÓÒ× ØÓÛ�Ö�× � Ø�×� Ø��Ø �× ÒÓØ

ÔÖ�×�ÒØ Ø�� ÔÖÓ����Ð�×Ø� ÓÑÔÓÒ�ÒØ Û�Ø� � ×ÙÔ�Ö�ÓÖ ���Ð�ØÝ

ØÓ ��Ø�ÖÑ�Ò� Û�� � Ø�×�× �Ö� ÔÖ�×�ÒØ �××ÙÑ�× ÓÒØÖÓÐ

ÁÒ �Ø× Ô�××�Ú� ÑÓÒ�ØÓÖ�Ò� ÑÓ�� Ø�� ÔÖÓ����Ð�×Ø� ÓÑÔÓ

Ò�ÒØ ÙÔ��Ø�× �Ø× ÔÖÓ����Ð�ØÝ ��×ØÖ��ÙØ�ÓÒ �Ò� �Ò�ÓÖÑ× ��ÓÔØ

Ë� Û��Ò Ø�� ×Ø�ØÙ× Ó� � Ø�×� ��Ò��× ÁÒ �Ø× � Ø�Ú� ÑÓ��

Ø�� ÔÖÓ����Ð�×Ø� ÓÑÔÓÒ�ÒØ Ø���× � Ø�ÓÒ× Û�� � ��Ñ ØÓ ��

Ø�ÖÑ�Ò� Ø�� ÔÖ�×�Ò � Ó� � Ø�×� �× ÕÙ� �ÐÝ �× ÔÓ××��Ð� ��Ø�Ö

Ñ�Ò�Ò� Û��Ø � Ø�ÓÒ Û�ÐÐ ÑÓ×Ø Ö����ÐÝ ��Ø�ÖÑ�Ò� Ø�� ÔÖ�×�Ò �

Ó� Ø�×�× �Ò �� ��×�ÐÝ �Ò��ÖÖ�� �ÖÓÑ �Ø× ×�Ò×ÓÖ ÑÓ��Ð Ì��Ø

�× Ø�� � Ø�ÓÒ Ø��Ø �× ÑÓ×Ø Ð���ÐÝ ØÓ Ö�×ÓÐÚ� ÙÒ �ÖØ��ÒØÝ ��Ú�Ò

Ø�� ÙÖÖ�ÒØ ×Ø�Ø� Ó� ÈÊ �× �Ó×�Ò

ÁÒ Ø�� �ÓÐÐÓÛ�Ò� �� � Ó� Ø�� ��«�Ö�ÒØ Ó�×�ÖÚ�Ø�ÓÒ× �Ö� ��×

Ù××�� �Ò ×ÓÑ� ��Ø��Ð ÁÒ Ø�� Ò�ÜØ ×� Ø�ÓÒ Ö�×ÙÐØ× Ù×�Ò� Ø��

�ÔÔÖÓ� � Û�Ø� Ö��Ð ��Ö�Û�Ö� �Ö� ÔÖ�×�ÒØ��

4.2 Using Observations to Reduce Uncertainty

Ì�� ÔÖÓ����Ð�ØÝ ��×ØÖ��ÙØ�ÓÒ ÓÚ�Ö Ø�×�× �Ò� �Ø× Ñ�ÔÔ�Ò�

ØÓ Î �Ò �× �Ø Ø�� ���ÖØ Ó� Ø�� �ÔÔÖÓ� � ÔÖ�×�ÒØ�� ��Ö�

À�Ò � Ñ��ÒØ��Ò�Ò� �× � ÙÖ�Ø� �× ÔÓ××��Ð� ��×ØÖ��ÙØ�ÓÒ �×

�××�ÒØ��Ð ØÓ Ø�� ×Ù �×× Ó� Ø�� �ÔÔÖÓ� � �Ö��Ø�Ò� �Ò� Ñ��Ò

Ø��Ò�Ò� Ø��× ��×ØÖ��ÙØ�ÓÒ �Ò � ÒÓ�×Ý �ÝÒ�Ñ� ÛÓÖÐ� Ö�ÕÙ�Ö�×

�ÓØ� ÓÑ��Ò�Ò� ÑÙÐØ�ÔÐ� Ñ��×ÙÖ�Ñ�ÒØ× ØÓ Ö��Ù � ÙÒ �Ö

Ø��ÒØÝ Û��Ð� ��Ú�Ò� ÑÓÖ� Û����Ø ØÓ Ø�� ÑÓ×Ø Ö� �ÒØ Ñ��

×ÙÖ�Ñ�ÒØ× ØÓ �Ò×ÙÖ� Ø�� ÙÖÖ�ÒØ ×�ØÙ�Ø�ÓÒ �× �ÔØÙÖ�� �ÓÙÖ

Ô�� �× Ó� �Ò�ÓÖÑ�Ø�ÓÒ �Ö� Ù×�� ØÓ ÙÔ��Ø� Ø�� ÔÖÓ����Ð�ØÝ ��×

ØÖ��ÙØ�ÓÒ

¯ ÍÔ��Ø�× ��×�� ÓÒ Ó�×�ÖÚ�Ø�ÓÒ× Ñ��� Û��Ð� Ô�Ö�ÓÖÑ�Ò�

� Ø�×� Ù×�Ò� � Ð��ÖÒ�� �ÒÚ�ÖÓÒÑ�ÒØ ÑÓ��Ð �ÓÖÑ�ÐÐÝ

Ø��× �Ò�ÓÖÑ�Ø�ÓÒ �× ÈÖ Ì �Ë Û��Ö� Ë �× � ×�Ò×ÓÖ Ö���

�Ò�

¯ ÍÔ��Ø�× Ñ��� ��×�� ÓÒ �Ò��Ö�Ò �× �ÖÓÑ ÓÚ�Ö���Ö� ÓÑ

ÑÙÒ� �Ø�ÓÒ× �ÖÓÑ ÓØ��Ö ÒÓ��× �ÓÖÑ�ÐÐÝ Ø��× �Ò�ÓÖÑ�

Ø�ÓÒ �× ÈÖ Ì �Å Û��Ö� Å �× � Ñ�××���

More magazines by this user
Similar magazines