#Research# Recently, Dr. Xiaowang Zhang from Tianjin University had solved the satisfiability problem of SPARQL 1.0 patterns, in collaboration with Prof. Jan Van den Bussche (Hasselt University, Belgium) and Dr. Francois Picalausa. The result has been published in Journal of Artificial Intelligence Research (56:403-428, 2016) (a leading journal in AI, sponsored by Association for the Advancement of Artificial Intelligence (AAAI)).
They found that whether or not a pattern is satisfiable depends mainly on the filter operations appearing in the pattern; without filter operations, a pattern is always satisfiable except for trivial cases where a literal occurs in the wrong place. Thus the goal of this work is to precisely delineate the decidability of SPARQL fragments that are defined in terms of the constraints that can be used as filter conditions. They define a notion called “strong consistency” for constraints and they found that the satisfiability problem of patterns of a given SPARQL 1.0 fragment is decidable if the constraints of the fragment satisfy strong consistency; and it becomes undecidable otherwise.
The finding in this paper may be summarized by saying that, as long as the kinds of constraints allowed in filter conditions cannot be combined to yield inconsistent sets of constraints, satisfiability for SPARQL patterns is decidable; otherwise, the problem is undecidable. This sharp result can help to paint a rather complete picture of the satisfiability problem for SPARQL 1.0. So this finding is a necessary step to paint a rather complete picture of the satisfiability problem for the full SPARQL 1.1.
They found that whether or not a pattern is satisfiable depends mainly on the filter operations appearing in the pattern; without filter operations, a pattern is always satisfiable except for trivial cases where a literal occurs in the wrong place. Thus the goal of this work is to precisely delineate the decidability of SPARQL fragments that are defined in terms of the constraints that can be used as filter conditions. They define a notion called “strong consistency” for constraints and they found that the satisfiability problem of patterns of a given SPARQL 1.0 fragment is decidable if the constraints of the fragment satisfy strong consistency; and it becomes undecidable otherwise.
The finding in this paper may be summarized by saying that, as long as the kinds of constraints allowed in filter conditions cannot be combined to yield inconsistent sets of constraints, satisfiability for SPARQL patterns is decidable; otherwise, the problem is undecidable. This sharp result can help to paint a rather complete picture of the satisfiability problem for SPARQL 1.0. So this finding is a necessary step to paint a rather complete picture of the satisfiability problem for the full SPARQL 1.1.
如上圖所說，#為工作你可以有幾盡 ?
今日9:30到現在00:22
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紅黃藍綠，同插入50隻蚊羣嘅草叢 !!!!
為嘅係1張靚景相 (想知就下週記得留意我的Ig/FB平台)
咁就短短10分鐘咬咗全腳全手共35粒
蚊蘭 !!!! 可能再多
做Artiste嘅辛酸唔講你真係唔會係
一張微笑嘅靚相發現到 !
不過好彩係最重要Final張相~>靚，
咁努力係絕對值得
#多年也是笑着做 #做事要盡力專業
#盡力而為
特別要感謝今天的朋友 @adriancheongxiii & heather
#HkArtiste #WinkieLai #OutdoorShooting
今日9:30到現在00:22
為咗影1張靚相，踏入一個超多昆蟲
紅黃藍綠，同插入50隻蚊羣嘅草叢 !!!!
為嘅係1張靚景相 (想知就下週記得留意我的Ig/FB平台)
咁就短短10分鐘咬咗全腳全手共35粒
蚊蘭 !!!! 可能再多
做Artiste嘅辛酸唔講你真係唔會係
一張微笑嘅靚相發現到 !
不過好彩係最重要Final張相~>靚，
咁努力係絕對值得
#多年也是笑着做 #做事要盡力專業
#盡力而為
特別要感謝今天的朋友 @adriancheongxiii & heather
#HkArtiste #WinkieLai #OutdoorShooting
#佛罗伦萨美术学院#Giovedì 11 maggio alle 17.00 nel chiostro
Giovedì 11 maggio alle 17.00 il Chiostro dell'Accademia di Belle Arti di Firenze ospiterà un concerto di quattro maestri del Conservatorio Luigi Cherubini.
PROGRAMMA:
Quartetto in Sol minore per fiati, Luigi Hughes
Paolo Zampini_flauto
Simone Bensi_oboe
Lorenzo Del Pecchia_clarinetto
Dušan Mamula_clarinetto basso
Giovedì 11 maggio alle 17.00 il Chiostro dell'Accademia di Belle Arti di Firenze ospiterà un concerto di quattro maestri del Conservatorio Luigi Cherubini.
PROGRAMMA:
Quartetto in Sol minore per fiati, Luigi Hughes
Paolo Zampini_flauto
Simone Bensi_oboe
Lorenzo Del Pecchia_clarinetto
Dušan Mamula_clarinetto basso
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