398,698 research outputs found
Dark matter in the Kim-Nilles mechanism
The Kim-Nilles mechanism relates the term with the axion scale ,
leading to the axino-Higgsino-Higgs Yukawa coupling of order . This
can bring a dangerous thermal production of axinos. If the axino is stable, its
mass has to be as small as (0.1keV), or the reheat temperature should
be lower than (10GeV) taking the lower axion scale GeV in
order not to overclose the Universe. If the axino decays to a neutralino, the
overproduced neutralinos can re-annihilate appropriately to saturate the
observed dark matter density if the annihilation rate is of order
for the axion scale larger than about GeV. Thus,
a light Higgsino-like lightest supersymmetric particle with a sizable bino
mixture becomes a good dark matter candidate whose nucleonic cross-section is
of order cm.Comment: 10 pages, 1 figure; Corrected errors in Eq.(7) and in the direct
detection cross-section of the Higgsino-like dark matter; Revised Fig.1;
Added a discussion on the saxion; Added references; to appear in PR
A Critical Review of "Automatic Patch Generation Learned from Human-Written Patches": Essay on the Problem Statement and the Evaluation of Automatic Software Repair
At ICSE'2013, there was the first session ever dedicated to automatic program
repair. In this session, Kim et al. presented PAR, a novel template-based
approach for fixing Java bugs. We strongly disagree with key points of this
paper. Our critical review has two goals. First, we aim at explaining why we
disagree with Kim and colleagues and why the reasons behind this disagreement
are important for research on automatic software repair in general. Second, we
aim at contributing to the field with a clarification of the essential ideas
behind automatic software repair. In particular we discuss the main evaluation
criteria of automatic software repair: understandability, correctness and
completeness. We show that depending on how one sets up the repair scenario,
the evaluation goals may be contradictory. Eventually, we discuss the nature of
fix acceptability and its relation to the notion of software correctness.Comment: ICSE 2014, India (2014
Real-Time 3D Image Guidance Using a Standard LINAC: Measured Motion, Accuracy, and Precision of the First Prospective Clinical Trial of Kilovoltage Intrafraction Monitoring-Guided Gating for Prostate Cancer Radiation Therapy.
PURPOSE: Kilovoltage intrafraction monitoring (KIM) is a new real-time 3-dimensional image guidance method. Unlike previous real-time image guidance methods, KIM uses a standard linear accelerator without any additional equipment needed. The first prospective clinical trial of KIM is underway for prostate cancer radiation therapy. In this paper we report on the measured motion accuracy and precision using real-time KIM-guided gating. METHODS AND MATERIALS: Imaging and motion information from the first 200 fractions from 6 patient prostate cancer radiation therapy volumetric modulated arc therapy treatments were analyzed. A 3-mm/5-second action threshold was used to trigger a gating event where the beam is paused and the couch position adjusted to realign the prostate to the treatment isocenter. To quantify the in vivo accuracy and precision, KIM was compared with simultaneously acquired kV/MV triangulation for 187 fractions. RESULTS: KIM was successfully used in 197 of 200 fractions. Gating events occurred in 29 fractions (14.5%). In these 29 fractions, the percentage of beam-on time, the prostate displacement was >3 mm from the isocenter position, reduced from 73% without KIM to 24% with KIM-guided gating. Displacements >5 mm were reduced from 16% without KIM to 0% with KIM. The KIM accuracy was measured at <0.3 mm in all 3 dimensions. The KIM precision was <0.6 mm in all 3 dimensions. CONCLUSIONS: Clinical implementation of real-time KIM image guidance combined with gating for prostate cancer eliminates large prostate displacements during treatment delivery. Both in vivo KIM accuracy and precision are well below 1 mm
Structural and optical properties of MOCVD AllnN epilayers
7] M.-Y. Ryu, C.Q. Chen, E. Kuokstis, J.W. Yang, G. Simin, M. Asif Khan, Appl. Phys. Lett. 80 (2002) 3730. [8] D. Xu, Y. Wang, H. Yang, L. Zheng, J. Li, L. Duan, R. Wu, Sci. China (a) 42 (1999) 517. [9] H. Hirayama, A. Kinoshita, A. Hirata, Y. Aoyagi, Phys. Stat. Sol. (a) 188 (2001) 83. [10] Y. Chen, T. Takeuchi, H. Amano, I. Akasaki, N. Yamada, Y. Kaneko, S.Y. Wang, Appl. Phys. Lett. 72 (1998) 710. [11] Ig-Hyeon Kim, Hyeong-Soo Park, Yong-Jo Park, Taeil Kim, Appl. Phys. Lett. 73 (1998) 1634. [12] K. Watanabe, J.R. Yang, S.Y. Huang, K. Inoke, J.T. Hsu, R.C. Tu, T. Yamazaki, N. Nakanishi, M. Shiojiri, Appl. Phys. Lett. 82 (2003) 718
Calculation of axion-photon-photon coupling in string theory
The axion search experiments invite a plausible estimation of the
axion--photon--photon coupling constant in
string models with phenomenologically acceptable visible sectors. We present
the calculation of with an exact Peccei-Quinn
symmetry. In the Huh-Kim-Kyae orbifold compactification, we obtain
even with a lot of singlets at the
GUT scale, and the low-temperature axion search experiments will probe the QCD
corrected coupling, .Comment: LaTeX file of 7 page
The semantic effects of verb raising and its consequences in second language grammars
This article considers whether highly proficient second language speakers of English can distinguish meaning contrasts associated with constructions where there is a raising be, and constructions where there is a non-raising thematic verb, as illustrated in the difference between (1a) and (1b): 1a. Kim is reading a novel (`event-in-progress/existential ? interpretation
Annealing Effect for Supersolid Fraction in He
We report on experimental confirmation of the non-classical rotational
inertia (NCRI) in solid helium samples originally reported by Kim and Chan. The
onset of NCRI was observed at temperatures below ~400 mK. The ac velocity for
initiation of the NCRI suppression is estimated to be ~10 m/sec. After an
additional annealing of the sample at K for 12 hours, ~ 10% relative
increase of NCRI fraction was observed. Then after repeated annealing with the
same conditions, the NCRI fraction was saturated. It differs from Reppy's
observation on a low pressure solid sample.Comment: to be published in J. of Low Temp. Phys. (QFS2006 proceedings
Depolarizing field and "real" hysteresis loops in nanometer-scale ferroelectric films
We give detailed analysis of the effect of depolarizing field in
nanometer-size ferroelectric capacitors studied by Kim et al. [Phys. Rev. Lett.
95, 237602 (2005)]. We calculate a critical thickness of the homogeneous state
and its stability with respect to domain formation for strained thin films of
BaTiO3 on SrRuO3/SrTiO3 substrate within the Landau theory. While the former
(2.5nm) is the same as given by ab-initio calculations, the actual critical
thickness is set by the domains at 1.6nm. There is a large Merz's activation
field for polarization relaxation. Remarkably, the results show a_negative_
slope of the "actual" hysteresis loops, a hallmark of the domain structures in
ideal thin films with imperfect screening.Comment: 4 pages, 2 figure
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