On the average complexity of the membership problem for a generalized Dyck language

1997 ◽  
pp. 352-363
Author(s):  
Markus E. Nebel
Keyword(s):  
Membership Problem ◽  
Average Complexity

WHEN CHURCH-ROSSER BECOMES CONTEXT FREE

2007 ◽  
Vol 18 (06) ◽  
pp. 1293-1302 ◽  
Author(s):  
MARTIN KUTRIB ◽  
ANDREAS MALCHER
Keyword(s):  
Linear Time ◽  
Membership Problem ◽  
Closure Properties ◽  
Context Free Language ◽  
Arithmetic Hierarchy ◽  
Context Free ◽  
Free Language

We investigate the intersection of Church-Rosser languages and (strongly) context-free languages. The intersection is still a proper superset of the deterministic context-free languages as well as of their reversals, while its membership problem is solvable in linear time. For the problem whether a given Church-Rosser or context-free language belongs to the intersection we show completeness for the second level of the arithmetic hierarchy. The equivalence of Church-Rosser and context-free languages is Π1-complete. It is proved that all considered intersections are pairwise incomparable. Finally, closure properties under several operations are investigated.

scholarly journals The Membership Problem in Jump Systems

1997 ◽  
Vol 70 (1) ◽  
pp. 45-66 ◽  
Author(s):  
László Lovász
Keyword(s):  
Membership Problem ◽  
Jump Systems

scholarly journals On the computational algorithm related to antikeys

2016 ◽  
Vol 14 (2) ◽  
pp. 1-7
Author(s):  
Vũ Đức Thi
Keyword(s):  
Time Complexity ◽  
Computational Algorithm ◽  
Functional Dependency ◽  
Membership Problem ◽  
Closed Set ◽  
Dependency Relation ◽  
Key Word ◽  
Relation Scheme

The keys and antikeys play important roles for the investigation of functional dependency in the relational datamodel. The main purpose of this paper is to prove that the time complexity of finding a set of antileys for a given relation scheme S is exponential in the number of attributes. Some another results connecting the functional dependency are given. Key Word and phrase: Relation, relational datamodel, functionsl dependency, relation scheme, generating Armstrong relation, dependency inference, strong schemen, membership problem, closure, closed set, minimal generater, key, minimal key, antikey.

scholarly journals Career Complexity No Longer on the Rise: Comparing Early- and Mid-Career Complexity Across the 1930s thru 1980s Birth Cohorts in Sweden

2021 ◽  
Author(s):  
Johan Westerman ◽  
Dirk Witteveen ◽  
Erik Bihagen ◽  
Roujman Shahbazian
Keyword(s):  
State Of The Art ◽  
Working Hours ◽  
Early Career ◽  
Initial Increase ◽  
Birth Cohorts ◽  
Work Lives ◽  
Average Complexity ◽  
Time Period ◽  
Long Time ◽  
Gender Convergence

There is a wide-spread idea that contemporary careers continue to become ever more complex. Pioneering research of full-career complexity has shown that work lives have indeed become more complex, yet at modest increasing pace. This paper examines whether career complexity continues to increase using Swedish registry data across an exceptionally long time period, including younger cohorts than in previous research: up to those born in 1983. The full early- and midcareers of selected birth cohorts cover several macroeconomic booms and downturns, a long period of upskilling of the Swedish labor force, as well as the convergence of working hours of women and men. The following conclusions are drawn using state-of-the-art methods of measuring career complexity. For early-careers, an increasing complexity trend is evident between the 1950s and 1960s birth cohorts, yet complexity fluctuates around a stable trend for the 1970s birth cohorts and onward. For mid-careers, which are considerably more stable on average, complexity has decreased among women born between the 1930s and the early-1950s. However, the opposite trend holds true for men, resulting in gender convergence of complexity. We observe a standstill of the mid-career complexity trend across both genders, followed by a modest decline for the last observed cohorts. Subsequent analyses point to educational expansion as an important driver of the initial increase of early-career complexity. Taken together, our analysis affirms an initial shift to more career complexity in the 20th century, yet we find no unidirectional trend toward more career complexity over the last decades.

Robotic Applications for Benign Gynecologic Procedures

2021 ◽  
Vol 39 ◽  
Author(s):  
Alexandria Connor ◽  
◽  
Resad Pasic ◽  
Amira Quevedo ◽  
Petra Chamseddine ◽  
...  
Keyword(s):  
Robotic Surgery ◽  
Robotic Training ◽  
Average Complexity ◽  
Fda Approval ◽  
Benign Gynecology ◽  
Distinct Features ◽  
Standardized Curriculum ◽  
Novice Surgeons ◽  
Robotic Applications

Introduction: Robotic systems provide a platform for surgeons to expand their capabilities, allowing them to perform complex procedures safely and efficiently. Within the field of benign gynecology, this has become an increasingly popular option since receiving Food and Drug Administration (FDA) approval in 2005. However, the appropriate indications for robotic versus laparoscopic surgery continue to be debated. Materials and Methods: Literature was reviewed to provide a comprehensive, evidence-based evaluation of the advantages and pitfalls of robotic surgery, the applications of robotic surgery for benign gynecologic procedures in comparison to conventional laparoscopy, and the role of robotic surgery as an educational tool. Results: Robotic surgery has favorable outcomes for surgeons in the areas of ergonomics, dexterity, and fatigue. Cost comparisons are widely varied and elaborate. Most patient outcomes are comparable between robotic and laparoscopic hysterectomies and endometriosis resections. In patients with a body mass index >30mg/m2 and uteri >750mg, hysterectomy outcomes are improved when surgery is done robotically. The use of the robotic system may be beneficial for patients undergoing myomectomy. Robotic surgery confers advantages for trainees and novice surgeons. There is no consensus on a standardized curriculum for robotic training or credentialing process for experienced surgeons. Conclusion: Robotic surgery has distinct features that make it a valuable tool for gynecologic surgeons. There are no clear indications regarding when a robotic route should be chosen but could be considered when above average complexity is anticipated and when training new surgeons.

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