Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Physical Sciences and Mathematics (8505)
- Computer Sciences (8488)
- Databases and Information Systems (3444)
- Software Engineering (2149)
- Artificial Intelligence and Robotics (1676)
-
- Information Security (1055)
- Numerical Analysis and Scientific Computing (1023)
- Engineering (955)
- Graphics and Human Computer Interfaces (924)
- Social and Behavioral Sciences (732)
- Business (684)
- Computer Engineering (511)
- Theory and Algorithms (493)
- Operations Research, Systems Engineering and Industrial Engineering (417)
- Programming Languages and Compilers (379)
- OS and Networks (322)
- Communication (310)
- Social Media (248)
- Public Affairs, Public Policy and Public Administration (226)
- Transportation (203)
- Medicine and Health Sciences (183)
- Education (177)
- Management Information Systems (177)
- Data Storage Systems (175)
- E-Commerce (151)
- International and Area Studies (125)
- Asian Studies (124)
- Digital Communications and Networking (123)
- Technology and Innovation (114)
- Health Information Technology (110)
- Keyword
-
- Deep learning (124)
- Machine learning (124)
- Social media (80)
- Artificial intelligence (71)
- Reinforcement learning (69)
-
- Data mining (65)
- Privacy (61)
- Cloud computing (58)
- Deep Learning (56)
- Empirical study (55)
- Optimization (55)
- Security (53)
- Singapore (52)
- Visualization (52)
- Twitter (50)
- Neural networks (49)
- Online learning (49)
- Software engineering (49)
- Training (49)
- Task analysis (48)
- Anomaly detection (47)
- Collaboration (45)
- Feature extraction (45)
- Blockchain (44)
- Large Language Models (44)
- Semantics (43)
- Access control (41)
- Algorithms (40)
- Android (39)
- Classification (38)
- Publication Year
- File Type
Articles 8551 - 8580 of 8678
Full-Text Articles in Entire DC Network
Improved Measurement Of The B0 And B+ Meson Lifetimes, D. Buskulic, M. Thulasidas
Improved Measurement Of The B0 And B+ Meson Lifetimes, D. Buskulic, M. Thulasidas
Research Collection School Of Computing and Information Systems
Updated measurements of the B0 and B+ meson lifetimes are presented. From a data sample of 1.72 million hadronic Z0 decays recorded during the period 1991 to 1993, a sample of approximately 1000 semileptonic B meson decays containing a D0, D+ or D*+ has been isolated. From the distribution of decay times in the different samples the lifetimes of the B0 and B+ mesons are determined to be 1.53±0.12±0.08 ps and 1.52±0.14±0.09 ps, respectively, where the first error is statistical and the second systematic. The ratio of the B+ to B0 lifetimes is measured to be 0.99±0.14+0.05−0.04, confirming expectations that …
Determination Of Sin2Θw Eff Using Jet Charge Measurements In Hadronic Z Decays, D. Buskulic, M. Thulasidas
Determination Of Sin2Θw Eff Using Jet Charge Measurements In Hadronic Z Decays, D. Buskulic, M. Thulasidas
Research Collection School Of Computing and Information Systems
The electroweak mixing angle is determined with high precision from measurements of the mean difference between forward and backward hemisphere charges in hadronic decays of the Z. A data sample of 2.5 million hadronic Z decays recorded over the period 1990 to 1994 in the ALEPH detector at LEP is used. The mean charge separation between event hemispheres containing the original quark and antiquark is measured forbb¯bb¯ andcc¯cc¯ events in subsamples selected by their long lifetimes or using fastD*’s. The corresponding average charge separation for light quarks is measured in an inclusive sample from the anticorrelation between charges of opposite …
Measurement Of The Λb Polarization In Z Decays, Buskulic, D.; Et Al., M. Thulasidas
Measurement Of The Λb Polarization In Z Decays, Buskulic, D.; Et Al., M. Thulasidas
Research Collection School Of Computing and Information Systems
The Λb polarization in hadronic Z decays is measured in semileptonic decays from the average energies of the charged lepton and the neutrino. In a data sample of approximately 3 million hadronic Z decays collected by the ALEPH detector at LEP between 1991 and 1994, 462 ± 31 Λb candidates are selected using (Λπ+)-lepton correlations. From this event sample, the Λb polarization is measured to be PΛb = −0.23−0.20+0.24(stat.)−0.07+0.08(syst.).
Combinatorial Approaches For Hard Problems In Manpower Scheduling, Hoong Chuin Lau
Combinatorial Approaches For Hard Problems In Manpower Scheduling, Hoong Chuin Lau
Research Collection School Of Computing and Information Systems
Manpower scheduling is concerned with the construction of a workers' schedule which meets demands while satisfying given constraints. We consider a manpower scheduling Problem, called the Change Shift Assignment Problem(CSAP). In previous work, we proved that CSAP is NP-hard and presented greedy methods to solve some restricted versions. In this paper, we present combinatorial algorithms to solve more general and realistic versions of CSAP which are unlikely solvable by greedy methods. First, we model CSAP as a fixed-charge network and show that a feasible schedule can be obtained by finding disjoint paths in the network, which can be derived from …
Randomized Approximation Of The Constraint Satisfaction Problem, Hoong Chuin Lau, Osamu Watanabe
Randomized Approximation Of The Constraint Satisfaction Problem, Hoong Chuin Lau, Osamu Watanabe
Research Collection School Of Computing and Information Systems
We consider the Weighted Constraint Satisfaction Problem (W-CSP) which is a fundamental problem in Artificial Intelligence and a generalization of important combinatorial problems such as MAX CUT and MAX SAT. In this paper, we prove non-approximability properties of W-CSP and give improved approximations of W-CSP via randomized rounding of linear programming and semidefinite programming relaxations. Our algorithms are simple to implement and experiments show that they are run-time efficient.
The Effects Of Conceptual And Logical Interfaces On Visual Query Performance Of End Users, Keng Siau, H. Chan, K. Wei
The Effects Of Conceptual And Logical Interfaces On Visual Query Performance Of End Users, Keng Siau, H. Chan, K. Wei
Research Collection School Of Computing and Information Systems
To the end users, the interface is the system. A better interface not only facilitates end user interaction with the database, it also enables them to formulate queries more efficiently and effectively. Two of the most important user-database interfaces are the conceptual and logical interfaces. With the conceptual interface, the user communicates with tile database system in terms ofentities, objects and relationships. On the other hand, the current user-database interaction is mainly based on the logical interface where the user expresses the queries in terms of relations and join operations. Because the concepts at the logical iliterface are abstract and …
Measurement Of The Bs0 Lifetime And Production Rate With Ds- ℓ+ Combinations In Z Decays, D. Buskulic, M. Thulasidas
Measurement Of The Bs0 Lifetime And Production Rate With Ds- ℓ+ Combinations In Z Decays, D. Buskulic, M. Thulasidas
Research Collection School Of Computing and Information Systems
A precise determination of the effective Bs0→K+K− lifetime can be used to constrain contributions from physics beyond the Standard Model in the Bs0 meson system. Conventional approaches select B meson decay products that are significantly displaced from the B meson production vertex. As a consequence, B mesons with low decay times are suppressed, introducing a bias to the decay time spectrum which must be corrected. This analysis uses a technique that explicitly avoids a lifetime bias by using a neural network based trigger and event selection. Using 1.0fb−1 of data recorded by the LHCb experiment, the effective Bs0→K+K− lifetime is …
Measurement Of The Effective B Quark Fragmentation Function At The Z Resonance, Buskulic, D.; Et Al., M. Thulasidas
Measurement Of The Effective B Quark Fragmentation Function At The Z Resonance, Buskulic, D.; Et Al., M. Thulasidas
Research Collection School Of Computing and Information Systems
Using a sample of about 1.46 million hadronic Z decays collected between 1991 and 1993 with the ALEPH detector at LEP, the energy distribution of the B0 and B± mesons produced at the Z resonance is measured by reconstructing semileptonic decays B → ℓνℓD(X) or B→ ℓνℓD∗+(X). The charmed mesons are reconstructed through the decay modes D0 → K−π+, D0 → K−π+π−π+, D+ → K−π+π+ and D∗+→ D0π+. The neutrino energy is estimated from the missing energy in the lepton hemisphere. Accounting for B∗ and B∗∗ production, the shape of the scaled energy distribution xE(b) for mesons containing a b …
Measurements Of The B Baryon Lifetime, D. Buskulic, Manoj Thulasidas
Measurements Of The B Baryon Lifetime, D. Buskulic, Manoj Thulasidas
Research Collection School Of Computing and Information Systems
The average lifetime of b-flavoured baryons measured with the OPAL detector is updated to include data collected between 1990 and 1994 at LEP. Bottom-flavoured baryons that decay semileptonically and produce aΛ baryon are identified through the correlation of the baryon number of theΛ and the electric charge of the lepton. To measure the lifetime, the decay point of the b baryon is estimated by theΛ-lepton vertex, and the observed distribution of decay lengths is fitted simultaneously in 874 right-sign and 384 wrong-sign combinations. In a separate method, the impact parameter distribution of the leptons is fitted in a subset of …
Group Creativity And Technology, Keng Siau
Group Creativity And Technology, Keng Siau
Research Collection School Of Computing and Information Systems
Despite the popularity of brainstorming, research has shown that verbal brainstorming is not always effective in increasing group creativity. On the other hand, its electronic counterpart, electronic brainstorming, appears to produce much better results. Is technology the panacea for group idea generation? This paper first reviews the theory of group creativity and then examines the characteristics of electronic brainstorming that makes it more effective than verbal brainstorming. From the success of electronic brainstorming, it then argues that the use of technology might be the key to overcome the space and time constraints that are commonly faced by creativity groups.
Measurement Of Αs From Scaling Violations In Fragmentation Functions In E+E- Annihilation, D. Buskulic, Manoj Thulasidas
Measurement Of Αs From Scaling Violations In Fragmentation Functions In E+E- Annihilation, D. Buskulic, Manoj Thulasidas
Research Collection School Of Computing and Information Systems
A study of scaling violations in fragmentation functions performed by the ALEPH collaboration at LEP is presented.
Measurement Of The D*± Cross Section In Two Photon Collisions At Lep, D. Buskulic, M. Thulasidas
Measurement Of The D*± Cross Section In Two Photon Collisions At Lep, D. Buskulic, M. Thulasidas
Research Collection School Of Computing and Information Systems
The inclusive production of D∗± mesons in photon-photon collisions has been measured by the Aleph experiment at LEP with a beam energy of 45 GeV. The D∗+ are detected in their decay to D0π+ with the D0 observed in three separate decay modes: (1) K−π+, (2) K−π+π0 and (3) K−π+π−π+, and analagously for the D∗− modes. A total of 33 events was observed from an integrated luminosity of 73 pb−1 which corresponds to a cross section for Σ(e+e−→ e+e−D∗±X) of 155 ± 33 ± 21 pb. This result is compatible with both the direct production γγ → cc in the …
Limit On B0s Oscillation Using A Jet Charge Method, D. Buskulic, M. Thulasidas
Limit On B0s Oscillation Using A Jet Charge Method, D. Buskulic, M. Thulasidas
Research Collection School Of Computing and Information Systems
A lower limit is set on the Bs0 meson oscillation parameter Δms using data collected from 1991 to 1994 by the ALEPH detector. Events with a high transverse momentum lepton and a reconstructed secondary vertex are used. The high transverse momentum leptons are produced mainly by b hadron decays, and the sign of the lepton indicates the particle/antiparticle final state in decays of neutral B mesons. The initial state is determined by a jet charge technique using both sides of the event. A maximum likelihood method is used to set a lower limit of Δms. The 95% confidence level lower …
An Experimental Investigation Of The Effect Of Expert Decision Analyses And Explanations Support On Consensus And Decision Accuracy In Small Groups, Fiona Fui-Hoon Nah, I. Benbasat
An Experimental Investigation Of The Effect Of Expert Decision Analyses And Explanations Support On Consensus And Decision Accuracy In Small Groups, Fiona Fui-Hoon Nah, I. Benbasat
Research Collection School Of Computing and Information Systems
An Expert Support System (ESS) provides expert advice to complement the knowledge of the decision maker, and is intended to support , rather than replace, the decision maker. The ESS technology provides two fundamental functions: (1) the ability to perform analyses and draw conclusions by providing users with expert opinions, judgments, evaluations and advice; (2) the ability to explain its reasoning and conclusions. The usefulness of expert support technology has been evaluated in a number of empirical studies. However these studies either examined the organizational impact of the technology [e.g., 1] or the use of the technology by single individuals …
Multiclass Query Scheduling In Real-Time Database Systems, Hwee Hwa Pang, Michael J. Carey, Miron Livny
Multiclass Query Scheduling In Real-Time Database Systems, Hwee Hwa Pang, Michael J. Carey, Miron Livny
Research Collection School Of Computing and Information Systems
In recent years, a demand for real-time systems that can manipulate large amounts of shared data has led to the emergence of real-time database systems (RTDBS) as a research area. This paper focuses on the problem of scheduling queries in RTDBSs. We introduce and evaluate a new algorithm called Priority Adaptation Query Resource Scheduling (PAQRS) for handling both single class and multiclass query workloads. The performance objective of the algorithm is to minimize the number of missed deadlines, while at the same time ensuring that any deadline misses are scattered across the different classes according to an administratively-defined miss distribution. …
Test Of The Flavour Independence Of Αs, D. Buskulic, Manoj Thulasidas
Test Of The Flavour Independence Of Αs, D. Buskulic, Manoj Thulasidas
Research Collection School Of Computing and Information Systems
Using about 950 000 hadronic events collected during 1991 and 1992 with the ALEPH detector, the ratios r b = bs=udsc s and r uds = uds s =cbs have been measured in order to test the avour independence of the strong coupling constant s . The analysis is based on event{shape variables using the full hadronic sample, two b-quark samples enriched by lepton tagging and lifetime tagging, and a light-quark sample enriched by lifetime antitagging. The combined results are r b = 1:002 0:023 and r uds = 0:971 0:023.
The Forward-Backward Asymmetry For Charm Quarks At The Z Pole, D. Buskulic, Manoj Thulasidas
The Forward-Backward Asymmetry For Charm Quarks At The Z Pole, D. Buskulic, Manoj Thulasidas
Research Collection School Of Computing and Information Systems
From 1.4 million hadronic Z decays collected by the ALEPH detector at LEP, an enriched sample of Z → cc̄ events is extracted by requiring the presence of a high momentum D∗±. The charm quark forward-backward charge asymmetry at the Z pole is measured to be AFB0.c = (8.0 ± 2.4) % corresponding to an effective electroweak mixing angle of sin2θWeff = 0.2302 ± 0.0054.
The Effect Of A Database Feedback System On User Performance, H. Chan, K. Wei, Keng Siau
The Effect Of A Database Feedback System On User Performance, H. Chan, K. Wei, Keng Siau
Research Collection School Of Computing and Information Systems
There are two main approaches to improving the effectiveness of database interfaces. One is to raise the level of abstraction for the content of the user-database interaction. The relational model belonging to the logical level has replaced the hierarchical and network models that belong to the lower physical level. It is likely that the relational model will eventually be replaced by models belonging to the even higher conceptual level, such as entity relationship models and object-oriented models. The second approach is to enhance the actual interaction process. This can be done by providing better feedback to the user. Feedback can …
Myriad: Design And Implementation Of A Federated Database Prototype, Ee Peng Lim, San-Yih Hwang, Jaideep Srivastava, Dave Clements, M. Ganesh
Myriad: Design And Implementation Of A Federated Database Prototype, Ee Peng Lim, San-Yih Hwang, Jaideep Srivastava, Dave Clements, M. Ganesh
Research Collection School Of Computing and Information Systems
A key problem in providing enterprise-wide information is the integration of databases that have been independently developed. An important requirement is to accommodate heterogeneity and maintain the autonomy of component databases. Myriad is a federated database prototype developed at the University of Minnesota, to provide a testbed for investigating alternatives in architecture and algorithms for database integration, query processing and optimization, and concurrency control and recovery. The system incorporates our group's research results in these areas. This paper describes our experiences in the design and implementation of Myriad, and in the project management. Special emphasis is given to discussing design …
Search For Supersymmetric Particles With R-Parity Violation In Z Decays, D. Buskulic, Manoj Thulasidas
Search For Supersymmetric Particles With R-Parity Violation In Z Decays, D. Buskulic, Manoj Thulasidas
Research Collection School Of Computing and Information Systems
Searches for supersymmetric particles produced in e+e− interactions at the Z peak have been performed under the assumptions that R-parity is not conserved, that the dominant R-parity violating coupling involves only leptonic fields, and that the lifetime of the lightest supersymmetric particle can be neglected. In a data sample collected by the ALEPH detector at LEP up to 1993, and corresponding to almost two million hadronic Z decays, no signal was observed. As a result, supersymmetric particle masses and couplings are at least as well constrained as under the usual assumption of R-parity conservation.
Exceptions And Exception Handling In Computerized Information Processes, Diane M. Strong, Steven M. Miller
Exceptions And Exception Handling In Computerized Information Processes, Diane M. Strong, Steven M. Miller
Research Collection School Of Computing and Information Systems
Exceptions, situations that cannot be correctly processed by computer systems, occur frequently in computer-based information processes. Five perspectives on exceptions provide insights into why exceptions occur and how they might be eliminated or more efficiently handled. We investigate these perspectives using an in-depth study of an operating information process that has frequent exceptions. Our results support the use of a total quality management (TQM) approach of eliminating exceptions for some exceptions, in particular, those caused by computer systems that are poor matches to organizational processes. However, some exceptions are explained better by a political system perspective of conflicting goals between …
An Upper Limit For The Τ Neutrino Mass From Τ → 5Π(Π0)Ντ Decays, D. Buskulic, M. Thulasidas
An Upper Limit For The Τ Neutrino Mass From Τ → 5Π(Π0)Ντ Decays, D. Buskulic, M. Thulasidas
Research Collection School Of Computing and Information Systems
From a sample of 152,000 τ decays collected by the ALEPH detector at LEP an upper limit of 24 MeV at 95% CL on the τ neutrino mass has been determined. The limit is obtained using a two dimensional likelihood fit of the visible energy and the invariant mass distribution of 25 τ → 5π(π0)ντ events.
Study Of The Subjet Structure Of Quark And Gluon Jets, D. Buskulic, D., M. Thulasidas
Study Of The Subjet Structure Of Quark And Gluon Jets, D. Buskulic, D., M. Thulasidas
Research Collection School Of Computing and Information Systems
Measurements of the subjet structure of quark and gluon jets in hadronic Z decays are presented. The analysis is based on one million hadronic events recorded by the Aleph detector. Roughly symmetric three-jet events are selected with a coarse jet-resolution cut-off, y1. Gluon jets are identified with a purity of 94.6% in those events where evidence of long-lived heavy-flavour hadrons in the other two jets is found. The jets are then analyzed using a smaller cut-off y0 (< y1) so that subjets are resolved. The properties of the jets (subjet multiplicities (Nq), (Ng) and rates Rng(q) for n = 1, 2, 3, 4) are determined and are found to be in good agreement with the expectations of perturbative QCD as long as the subjet resolution parameter y0 is sufficiently large to keep non-perturbative effects small. In particular, the ratio , which to leading order in QCD is given by the ratio of colour factors , is measured to be 1.96 ± 0.15 for y0 = 2 · 10−3, but falls to 1.29 ± 0.03 for y0 = 1.6 · 10−5.
Michel Parameters And Τ Neutrino Helicity From Decay Correlations In Z → Τ+Τ-, D. Buskulic, Manoj Thulasidas
Michel Parameters And Τ Neutrino Helicity From Decay Correlations In Z → Τ+Τ-, D. Buskulic, Manoj Thulasidas
Research Collection School Of Computing and Information Systems
No abstract provided.
A Type I Hybrid Arq System With Adaptive Code Rates, Robert H. Deng, Michael L. Lin
A Type I Hybrid Arq System With Adaptive Code Rates, Robert H. Deng, Michael L. Lin
Research Collection School Of Computing and Information Systems
Type I hybrid ARQ systems use an error-control code of fixed rate for error-correction in each transmitted packet. In such systems, the code rate must be carefully chosen to match the channel bit error rate (BER) in order to maximize system throughput. Whenever there is a mismatch between code rate and channel BER, the throughput suffers. In this paper, we proposed a type I hybrid ARQ system which automatically adjusts its code rates to match channel BERs. The proposed system is very simple to implement and yet performs significantly better than type I hybrid ARQ systems of fixed code rate
A Study Of D*+ Π- Production In Semileptonic B Decay, D. Buskulic, M. Thulasidas
A Study Of D*+ Π- Production In Semileptonic B Decay, D. Buskulic, M. Thulasidas
Research Collection School Of Computing and Information Systems
In a sample of 1.5 million hadronic decays of the Z collected by the ALEPH detector, a search is carried out for the decays B→ D10(2420)l−νX and B→ D2∗0(2460)l−νX. The product branching ratio for D10 production is measured to be Br(b →B) × Br(B→ D10l−νX) × Br(D10→ D∗+π−) = (2.04 ± 0.58stat± 0.34syst) × 10−3, and a 95% confidence level limit of Br(b →B) × Br(B→ D2∗0l−νX) × Br(D2∗0→ D∗+π−) ≤ 0.81 × 10−3 is obtained for D2∗0 production.A topological search sensitive to the processes above, but also to wide resonances that decay to D∗+π− and to non-resonant D∗+π− production …
Production Of Excited Beauty States In Z Decays, D. Buskulic, Manoj Thulasidas
Production Of Excited Beauty States In Z Decays, D. Buskulic, Manoj Thulasidas
Research Collection School Of Computing and Information Systems
A data sample of about 3.0 million hadronic Z decays collected by the ALEPH experiment at LEP in the years 1991 through 1994, is used to make an inclusive selection of B hadron events.
Inclusive Production Of Neutral Vector Mesons In Hadronic Z Decays, D. Buskulic, Manoj Thulasidas
Inclusive Production Of Neutral Vector Mesons In Hadronic Z Decays, D. Buskulic, Manoj Thulasidas
Research Collection School Of Computing and Information Systems
Data on the inclusive production of the neutral vector mesonsρ 0(770),ω(782), K*0(892), andφ(1020) in hadronic Z decays recorded with the ALEPH detector at LEP are presented and compared to Monte Carlo model predictions. Bose-Einstein effects are found to be important in extracting a reliable value for theρ 0 production rate. An averageρ 0 multiplicity of 1.45±0.21 per event is obtained. Theω is detected via its three pion decay modeω→π + π − π 0 and has a total rate of 1.07±0.14 per event. The multiplicity of the K*0 is 0.83±0.09, whilst that of theφ is 0.122±0.009, both measured using their …
Improved Tau Polarisation Measurement, D. Buskulic, M. Thulasidas
Improved Tau Polarisation Measurement, D. Buskulic, M. Thulasidas
Research Collection School Of Computing and Information Systems
Using 22 pb−1 of data collected at LEP in 1992 on the peak of the Z resonance, the ALEPH collaboration has measured the polarisation of the tau leptons decaying intoevv¯,μvv¯evv¯,μvv¯,πν, ρν and a1 ν from their individual decay product distributions. The measurement of the tau polarisation as a function of the production polar angle yields the two parametersN τ andN e, where, in terms of the axial and vector couplingsg Al andg Vl,N l=2g Vl gAl/(g 2Vl+g2Al). This analysis follows to a large extent the methods devised for the 1990 and 1991 data but with improvements which bring a better …
Adaptive Resonance Associative Map, Ah-Hwee Tan
Adaptive Resonance Associative Map, Ah-Hwee Tan
Research Collection School Of Computing and Information Systems
This article introduces a neural architecture termed Adaptive Resonance Associative Map (ARAM) that extends unsupervised Adaptive Resonance Theory (ART) systems for rapid, yet stable, heteroassociative learning. ARAM can be visualized as two overlapping ART networks sharing a single category field. Although ARAM is simpler in architecture than another class of supervised ART models known as ARTMAP, it produces classification performance equivalent to that of ARTMAP. As ARAM network structure and operations are symmetrical, associative recall can be performed in both directions. With maximal vigilance settings, ARAM encodes pattern pairs explicitly as cognitive chunks and thus guarantees perfect storage and recall …