3,222 research outputs found
EXIT-charts-aided hybrid multiuser detector for multicarrier interleave-division multiple access
A generically applicable hybrid multiuser detector (MUD) concept is proposed by appropriately activating different MUDs in consecutive turbo iterations based on the mutual information (MI) gain. It is demonstrated that the proposed hybrid MUD is capable of approaching the optimal Bayesian MUD's performance despite its reduced complexity, which is at a modestly increased complexity in comparison with that of the suboptimum soft interference cancellation (SoIC) MU
Recommended from our members
Research advances towards large-scale solar hydrogen production from water
The Improvement of Neural Network Cascade-Correlation Algorithm and Its Application in Picking Seismic First Break
Neural Network is a kind of widely used seismic wave travel time auto-picking method. Most commercial software such as Promax often uses Back Propagation (BP) neural network. Here we introduce a cascade-correlation algorithm for constructing neural network. The algorithm’s convergence is faster than BP algorithm and can determine its own network architecture according to training samples, in addition, it can be able to expand network topology to learn new samples. The cascaded-correlation algorithm is improved. Different from the standard cascade-correlation algorithm, improved algorithm starts at an appropriate BP network architecture (exits hidden units), but the standard one’s initial network only includes input layer and output layer. In addition, in order to prevent weight-illgrowth, adding regularization term to the objective function when training candidate hidden units can decay weights. The simulation experiment demonstrates that improved cascade-correlation algorithm is faster convergence speed and stronger generalization ability. Analytically study five attributes, including instantaneous intensity ratio, amplitude, frequency, curve length ratio, adjacent seismic channel correlation. Intersection figure shows that these five attributes have distinctiveness of first break and stability. The neural network first break picking method of this paper has achieved good effect in testing actual seismic data.Key words: Neural network; Cascade-correlation algorithm; Picking seismic first brea
Nuclear charge radii in Bayesian neural networks revisited
In this work, a refined Bayesian neural network (BNN) based approach with six
inputs including the proton number, mass number, and engineered features
associated with the pairing effect, shell effect, isospin effect, and
``abnormal" shape staggering effect of Hg, is proposed to
accurately describe nuclear charge radii. The new approach is able to well
describe the charge radii of atomic nuclei with and . The
standard root-mean-square (rms) deviation is fm for both the training
and validation data. In particular, the predicted charge radii of proton-rich
and neutron-rich calcium isotopes are found in good agreement with data. We
further demonstrate the reliability of the BNN approach by investigating the
variations of the rms deviation with extrapolation distances, mass numbers, and
isospin asymmetries.Comment: 16 pages, 6 figure
Prospects of violation in decay with polarized electron beam at STCF
Based on Monte
Carlo (MC) events produced from a longitudinally-polarized electron beam, the
sensitivity of violation of decay is studied with fast
simulation software. In addition, the decay can also be used as a process to optimize the detector
response using the interface provided by the fast simulation software. In the
future, STCF is expected to obtain 3.4 trillion events, and the
statistical sensitivity of violation of decay via process is expected to reach ~ when the electron beam polarization is 80\%
Ovarian cancer initially presenting with isolated ipsilateral superficial inguinal lymph node metastasis: a case study and review of the literature
Isolated superficial inguinal metastases without any extended intra-abdominal spread is a rare event in patients with ovarian carcinoma. Here we report an isolated superficial inguinal metastasis in a patient with primary ovarian cancer. A 54-year-old Chinese patient with primary ovarian cancer, had an isolated painless enlarged right groin swelling (3×2cm) as the only manifestation, preoperative pathology confirmed metastatic adenocarcinoma. Gynecologic examination, transvaginal ultrasonography of the abdominopelvic cavity revealed a 5-cm mixed, right adnexal mass. At exploratory laparotomy, there was little intra-abdominal tumor dissemination but 100 ml of faint yellow peritoneal fluid and a 5-cm right ovarian tumor with intact capsule. Staging operation was performed and postoperative pathology confirmed adenocarcinoma located within right ovarian, with no evidence of involvement of other sites. Then the patient received adjuvant chemotherapy for Stage IVB. Five years later, the patient is currently still alive without evidence of recurrent disease. This case indicate that ovarian carcinoma isn’t a disease localized only within the intra-peritoneal cavity, isolated superficial inguinal lymph node metastasis might occur in rare cases via potential lymphatic and (or) hematogenous route under special conditions. We propose the need to investigate the possible mechanisms, risk factors, metastatic patterns, the biology and natural history of such patients in a large-scale and multicenter analysis. Furthermore, efforts should be made for earlier and differential diagnosis and finally prolong survival time for such patients
Topological surface electronic states in candidate nodal-line semimetal CaAgAs
We investigate systematically the bulk and surface electronic structure of
the candidate nodal-line semimetal CaAgAs by angle resolved photoemission
spectroscopy and density functional calculations. We observed a metallic,
linear, non--dispersive surface band that coincides with the
high-binding-energy part of the theoretical topological surface state, proving
the topological nontriviality of the system. An overall downshift of the
experimental Fermi level points to a rigid-band-like -doping of the samples,
due possibly to Ag vacancies in the as-grown crystals.Comment: 6 pages, 5 figure
- …