3,422 research outputs found
The Slater approximation for Coulomb exchange effects in nuclear covariant density functional theory
The relativistic local density approximation (LDA) for the Coulomb exchange
functional in nuclear systems is presented. This approximation is composed of
the well-known Slater approximation in the non-relativistic scheme and the
corrections due to the relativistic effects. Its validity in finite nuclei is
examined by comparing with the exact treatment of the Coulomb exchange term in
the relativistic Hartree-Fock-Bogoliubov theory. The relativistic effects are
found to be important and the exact Coulomb exchange energies can be reproduced
by the relativistic LDA within 5% demonstrated by the semi-magic Ca, Ni, Zr,
Sn, and Pb isotopes from proton drip line to neutron drip line.Comment: 6 pages and 4 figure
Design and Development of Problem-Base Asynchronous Collaborative Learning
This paper describes the initial stages of designing
and developing Problem-Base Learning (PBL) in
engineering education via asynchronous collaborative
learning (ACL) at Open University Malaysia (OUM).
PBL development is aim at developing total integrated
approach to the learning system to induce active self-
managed learning and online forum participation among
learners. PBL approach is vital for open universities as
self-managed learning dominate the learning mode. This
paper will elaborate on the OUM learning system in
teaching engineering education and suggest new
approach of designing the curriculum based on PBL to
encourage student-centred learning through ACL via
Learning Management System (myLMS) platform of
OUM. (Authors' abstract
Optimal Acceleration-Velocity-Bounded Trajectory Planning in Dynamic Crowd Simulation
Creating complex and realistic crowd behaviors, such as pedestrian navigation behavior with dynamic obstacles, is a difficult and time consuming task. In this paper, we study one special type of crowd which is composed of urgent individuals, normal individuals, and normal groups. We use three steps to construct the crowd simulation in dynamic environment. The first one is that the urgent individuals move forward along a given path around dynamic obstacles and other crowd members. An optimal acceleration-velocity-bounded trajectory planning method is utilized to model their behaviors, which ensures that the durations of the generated trajectories are minimal and the urgent individuals are collision-free with dynamic obstacles (e.g., dynamic vehicles). In the second step, a pushing model is adopted to simulate the interactions between urgent members and normal ones, which ensures that the computational cost of the optimal trajectory planning is acceptable. The third step is obligated to imitate the interactions among normal members using collision avoidance behavior and flocking behavior. Various simulation results demonstrate that these three steps give realistic crowd phenomenon just like the real world
A Methylene Blue-Selective Membrane Electrode Using Methylene Blue-Phosphotungstate as Electroactive Material and its Pharmaceutical Applications
A methylene blue poly (vinyl chloride) membrane electrode based on methylene blue-phosphotungstate ion-pair complex as electroactive material is described. The linear response covered the range of 1 Ă— 10–3 – 1 Ă— 10–6 mol dm–3 methylene blue solution, with a slope of 51.5 ±0.8 mV/decade (pH range 3.0–10.0). The detection limit was 6.79 Ă— 10–7 mol dm–3. The electrode showed stability, good reproducibility and a fast response. Interferences from common inorganic cations and some organic bases were negligible. These characteristics of the electrode enabled its successful use for determination of methylene blue in injection. There was good agreement for the results of methylene blue content in injection between the potentiometric method and the United States Pharmacopoeia standard procedure
Transformations in Learned Image Compression from a Modulation Perspective
In this paper, a unified transformation method in learned image
compression(LIC) is proposed from the perspective of modulation. Firstly, the
quantization in LIC is considered as a generalized channel with additive
uniform noise. Moreover, the LIC is interpreted as a particular communication
system according to the consistency in structures and optimization objectives.
Thus, the technology of communication systems can be applied to guide the
design of modules in LIC. Furthermore, a unified transform method based on
signal modulation (TSM) is defined. In the view of TSM, the existing
transformation methods are mathematically reduced to a linear modulation. A
series of transformation methods, e.g. TPM and TJM, are obtained by extending
to nonlinear modulation. The experimental results on various datasets and
backbone architectures verify that the effectiveness and robustness of the
proposed method. More importantly, it further confirms the feasibility of
guiding LIC design from a communication perspective. For example, when backbone
architecture is hyperprior combining context model, our method achieves
3.52 BD-rate reduction over GDN on Kodak dataset without increasing
complexity.Comment: 10 pages, 8 figure
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