127 research outputs found
Approximate-At-Most-k Encoding of SAT for Soft Constraints
In the field of Boolean satisfiability problems (SAT), at-most-k constraints,
which suppress the number of true target variables at most k, are often used to
describe objective problems. At-most-k constraints are used not only for
absolutely necessary constraints (hard constraints) but also for challenging
constraints (soft constraints) to search for better solutions. To encode
at-most-k constraints into Boolean expressions, there is a problem that the
number of Boolean expressions basically increases exponentially with the number
of target variables, so at-most-k often has difficulties for a large number of
variables. To solve this problem, this paper proposes a new encoding method of
at-most-k constraints, called approximate-at-most-k, which has totally fewer
Boolean expressions than conventional methods on the one hand. On the other
hand, it has lost completeness, i.e., some Boolean value assignments that
satisfy the original at-most-k are not allowed with approximate-at-most-k;
hence, it is called approximate. Without completeness, we still have potential
benefits by using them only as soft constraints. For example,
approximate-at-most-16 out of 32 variables requires only 15% of a conventional
at-most-k on the literal number and covers 44% of the solution space. Thus,
approximate-at-most-k can become an alternative encoding method for at-most-k,
especially as soft constraints.Comment: 9 pages, 6 figures, 14th Pragmatics of SAT international workshop
(PoS2023): accepte
Impact of New beta-decay Half-lives on r-process Nucleosynthesis
We investigate the effects of newly measured beta-decay half-lives on
r-process nucleosynthesis. These new rates were determined by recent
experiments at the radioactive isotope beam factory facility in the RIKEN
Nishina Center. We adopt an r-process nucleosynthesis environment based on a
magnetohydrodynamic supernova explosion model that includes strong magnetic
fields and rapid rotation of the progenitor. A number of the new beta-decay
rates are for nuclei on or near the r-process path, and hence they affect the
nucleosynthesis yields and time scale of the r-process. The main effect of the
newly measured beta-decay half-lives is an enhancement in the calculated
abundance of isotopes with mass number A = 110 -- 120 relative to calculated
abundances based upon beta-decay rates estimated with the finite-range droplet
mass model. This effect slightly alleviates, but does not fully explain, the
tendency of r-process models to underproduce isotopes with A = 110 -- 120
compared to the solar-system r-process abundances.Comment: 9 pages, 3 figures, 1 table, published in PR
Soft Tissue Myoepithelioma of the Shoulder
Soft tissue myoepitheliomas are often misdiagnosed due to their rarity. Herein, we describe a case of soft tissue myoepithelioma of the shoulder. A 72-year-old woman had a suspected sarcoma on her shoulder and under-went open biopsy. She was referred to our hospital, where the tumor was widely resected and the diagnosis of myoepithelioma was histologically confirmed. No recurrence has been observed in the 3 years since the sur-gery. Careful and prompt planning is necessary for the effective treatment of myoepithelioma
Impact of quadrupole deformation on intermediate-energy heavy-ion collisions
This study employs the isospin-dependent Boltzmann-Uehling-Uhlenbeck model to
simulate intermediate-energy heavy-ion collisions between prolate nuclei
Mg. The emphasis is on investigating the influence of centrality and
orientation in several collision scenarios. The final-state particle
multiplicities and anisotropic flows are primarily determined by the
eccentricity and the area of the initial overlap. This not only provides
feedback on the collision systems, but also, to some extent, provides a means
to explore the fine structure inside deformed nuclei. Additionally,
non-polarized collisions have been further discussed. These results contribute
to the understanding of the geometric effects in nuclear reactions, and aid in
the exploration of other information on reaction systems, such as the equation
of state and nuclear high-momentum tail
Salmonella Osteomyelitis of the Distal Tibia in a Healthy Woman
Salmonella osteomyelitis is extremely rare; only a few cases have been reported in healthy adults. We describe a case of salmonella osteomyelitis in an otherwise healthy 20-year-old Japanese woman who presented with distal tibial pain. X-ray and magnetic resonance imaging showed a lesion suspected to be a bone cyst. Osteomyelitis was diagnosed when pus was observed during an open biopsy. The bacterial culture examination yielded salmonella. Surgical drainage and antibiotic treatment were performed, after which no recurrence was observed. To our best knowledge, this is the first report of salmonella osteomyelitis of the distal tibia in an otherwise healthy individual
Heavy Element Production in Inhomogeneous Big Bang Nucleosynthesis
We present a new astrophysical site of the big bang nucleosynthesis (BBN)
that are very peculiar compared with the standard BBN. Some models of the
baryogenesis suggest that very high baryon density regions were formed in the
early universe. On the other hand, recent observations suggest that heavy
elements already exist in high red-shifts and the origin of these elements
become a big puzzle. Motivated by these, we investigate BBN in very high baryon
density regions. BBN proceeds in proton-rich environment, which is known to be
like the p-process. However, by taking very heavy nuclei into account, we find
that BBN proceeds through both the p-process and the r-process simultaneously.
P-nuclei such as 92Mo, 94Mo, 96Ru, 98Ru whose origin is not well known are also
synthesized.Comment: 6 pages, 7 figure
Design report of the KISS-II facility for exploring the origin of uranium
One of the critical longstanding issues in nuclear physics is the origin of
the heavy elements such as platinum and uranium. The r-process hypothesis is
generally supported as the process through which heavy elements are formed via
explosive rapid neutron capture. Many of the nuclei involved in heavy-element
synthesis are unidentified, short-lived, neutron-rich nuclei, and experimental
data on their masses, half-lives, excited states, decay modes, and reaction
rates with neutron etc., are incredibly scarce. The ultimate goal is to
understand the origin of uranium. The nuclei along the pathway to uranium in
the r-process are in "Terra Incognita". In principle, as many of these nuclides
have more neutrons than 238U, this region is inaccessible via the in-flight
fragmentation reactions and in-flight fission reactions used at the present
major facilities worldwide. Therefore, the multi-nucleon transfer (MNT)
reaction, which has been studied at the KEK Isotope Separation System (KISS),
is attracting attention. However, in contrast to in-flight fission and
fragmentation, the nuclei produced by the MNT reaction have characteristic
kinematics with broad angular distribution and relatively low energies which
makes them non-amenable to in-flight separation techniques. KISS-II would be
the first facility to effectively connect production, separation, and analysis
of nuclides along the r-process path leading to uranium. This will be
accomplished by the use of a large solenoid to collect MNT products while
rejecting the intense primary beam, a large helium gas catcher to thermalize
the MNT products, and an MRTOF mass spectrograph to perform mass analysis and
isobaric purification of subsequent spectroscopic studies. The facility will
finally allow us to explore the neutron-rich nuclides in this Terra Incognita.Comment: Editors: Yutaka Watanabe and Yoshikazu Hirayam
Cancer of Unknown Primary Site:A Review of 28 Cases and the Efficacy of Cisplatin/Docetaxel Therapy at a Single Institute in Japan
We evaluated the efficacy and toxicity of cisplatin/docetaxel (CDDP/TXT) chemotherapy and identified prognostic factors in Japanese patients with cancer of unknown primary site (CUP). Twenty-eight consecutive patients seen at a single institute were reviewed retrospectively. Sixteen patients were treated with TXT 80mg/m2, followed by CDDP 75mg/m2. The overall response rate to CDDP/TXT treatment was 62.5%, with a median survival time (MST) of 22.7 months. Common adverse reactions were myelosuppression and hyponatremia. The MST of all 28 patients with CUP was 8.3 months, and the 1-year overall survival rate was 45.6%. Univariate analysis identified 5 prognostic factors:performance status, liver involvement, bone involvement, pleural involvement, and lymph node involvement. In conclusion, CDDP/TXT chemotherapy is effective with tolerable toxicity in patients with CUP. Japanese patients with CUP might be chemosensitive and may survive longer
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