3,287 research outputs found
Kinerja Portofolio Optimal Berdasarkan Model Indeks Tunggal
Tujuan penelitian ini adalah untuk mengetahui bagaimana kinerja portofolio optimal pada sektor basic industry and chemicals dan sektor trade, service, and investment pada Januari 2015 hingga Januari 2016 sebagai 2 sektor yang memiliki koefisien korelasi terendah antar sektor. Penelitian ini dilakukan di Perusahaan yang terdaftar di BEI dan tergabung dalam sektor basic industry and chemicals dan sektor trade, service, and investment. Jumlah sampel yang di ambil sebanyak 173 Perusahaan, dengan metode sampling sensus. Pengumpulan data dilakukan dengan cara observasi non perilaku. Berdasarkan hasil perhitungan ditemukan bahwa terdapat 2 saham optimal pada masing-masing sektor yang selanjutnya di silang menjadi portofolio A, B, C, dan D. Setelah melakukan pengukuran kinerja untuk diperingkat didapatkan portofolio C dengan kinerja terbaik yang memberikan return yang lebih tinggi pada tingkat risiko sistematis yang relatif sama dibandingkan portofolio lainnya
The Littlest Higgs
We present an economical theory of natural electroweak symmetry breaking,
generalizing an approach based on deconstruction. This theory is the smallest
extension of the Standard Model to date that stabilizes the electroweak scale
with a naturally light Higgs and weakly coupled new physics at TeV energies.
The Higgs is one of a set of pseudo Goldstone bosons in an
nonlinear sigma model. The symmetry breaking scale is around a TeV, with
the cutoff \Lambda \lsim 4\pi f \sim 10 TeV. A single electroweak doublet,
the ``little Higgs'', is automatically much lighter than the other pseudo
Goldstone bosons. The quartic self-coupling for the little Higgs is generated
by the gauge and Yukawa interactions with a natural size ,
while the top Yukawa coupling generates a negative mass squared triggering
electroweak symmetry breaking. Beneath the TeV scale the effective theory is
simply the minimal Standard Model. The new particle content at TeV energies
consists of one set of spin one bosons with the same quantum numbers as the
electroweak gauge bosons, an electroweak singlet quark with charge 2/3, and an
electroweak triplet scalar. One loop quadratically divergent corrections to the
Higgs mass are cancelled by interactions with these additional particles.Comment: 15 pages. References added. Corrected typos in the discussion of the
top Yukawa couplin
Correlational Origin of the Roton Minimum
We present compelling evidence supporting the conjecture that the origin of
the roton in Bose-condensed systems arises from strong correlations between the
constituent particles. By studying the two dimensional bosonic dipole systems a
paradigm, we find that classical molecular dynamics (MD) simulations provide a
faithful representation of the dispersion relation for a low- temperature
quantum system. The MD simulations allow one to examine the effect of coupling
strength on the formation of the roton minimum and to demonstrate that it is
always generated at a sufficiently high enough coupling. Moreover, the
classical images of the roton-roton, roton-maxon, etc. states also appear in
the MD simulation spectra as a consequence of the strong coupling.Comment: 7 pages, 4 figure
Collective Modes in Strongly Coupled Elecronic Bilayer Liquids
We present the first reliable calculation of the collective mode structure of
a strongly coupled electronic bilayer. The calculation is based on a classical
model through the frequency-moment-sum-rule preserving Quasi Localized
Charge Approximation, using the recently calculated Hypernetted Chain pair
correlation functions. The spectrum shows an energy gap at and the
absence of a previously conjectured dynamical instability.Comment: 4 pages, 4 .ps figure
Dielectric function of a two-component plasma including collisions
A multiple-moment approach to the dielectric function of a dense non-ideal
plasma is treated beyond RPA including collisions in Born approximation. The
results are compared with the perturbation expansion of the Kubo formula. Sum
rules as well as Ward identities are considered. The relations to optical
properties as well as to the dc electrical conductivity are pointed out.Comment: latex, 10 pages, 7 figures in ps forma
The effect of acidosis on the labelling of urinary ammonia during infusion of [amide-15N]glutamine in human subjects
In three experiments [amide-15N]glutamine was infused intravenously in male volunteers. After 4-8 h of infusion acidosis was achieved by an oral dose of CaCl2 (1 mmol/kg). In one subject acidosis was maintained for 5 d. The acid load produced an approximately 3-fold increase in urinary NH3 excretion, with a small (approximately 20%) and transient increase in the isotope abundance of urinary NH3 Estimates of glutamine production rate (flux) were obtained in two experiments. There was no evidence that it was increased in acidosis. The extra NH3 production by the kidney represented only a very small part, about 3%, of the total glutamine production rat
Evidence for Interlayer Collapse of Nontronite on Mars from Laboratory Visible and Near-IR Reflective Spectra
Dioctahedral smectites (e.g., nontronite and montmorillionite) are interpreted to occupy the optical surface of Mars at a number of locations on the basis of spectral features derived from interlayer H2O and MOH (M=Fe(3+)2, Fe(3+)Al, Al2, etc.) as observed by orbiting MRO-CRISM and MEx-OMEGA hyperspectral imaging spectrometers. At wavelengths shorter than approximately 2.7 micrometers, the strongest bands from interlayer H2O occur at approximately 1.4 and 1.9 micrometers from 2v1 and v1+v2, respectively, where v1 and v2 are the fundamental stretching and bending vibrations of the H2O molecule. Smectite MOH vibrations occur near 1.4 micrometers (stretching overtone) and in the region between 2.1 and 2.7 micrometers (stretching + bending combination). Because interlayer H2O can exchange with the martian environment, a number of studies have examined the strength of the interlayer H2O spectral features under Mars-like environmental conditions. The relationship between spectral properties and the underlying crystal structure of the smectites was not determined, and the extent of interlayer H2O removal was not established. We report combined visible and near-IR (VNIR), Mossbauer (MB), and powder X-ray diffraction (XRD) data for samples of the Fe-bearing smectite nontronite where the interlayer was collapsed by complete removal of interlayer H2O
Visible and Near-IR Reflectance Spectra of Mars Analogue Materials Under Arid Conditions for Interpretation of Martian Surface Mineralogy
Visible and near-IR (VNIR) spectra from the hyper-spectral imagers MRO-CRISM and Mars Express OMEGA in martian orbit have signatures from Fe-bearing phases (e.g., olivine, pyroxene, and jarosite), H2O/OH-bearing phases (e.g., smectites and other phyllosilicates, sulfates, and high-SiO2 phases), and carbonate [e.g., 1-5]. Mineralogical assignments of martian spectral features are made on the basis of VNIR spectra acquired in the laboratory under appropriate environmental conditions on samples whose mineralogical composition is known. We report here additional results for our ongoing project [6] to acquire VNIR spectra under arid conditions
Measurement of the flux of atmospheric muons with the CAPRICE94 apparatus
A new measurement of the momentum spectra of both positive and negative muons
as function of atmospheric depth was made by the balloon-borne experiment
CAPRICE94. The data were collected during ground runs in Lynn Lake on the
19-20th of July 1994 and during the balloon flight on the 8-9th of August 1994.
We present results that cover the momentum intervals 0.3-40 GeV/c for negative
muons and 0.3-2 GeV/c for positive muons, for atmospheric depths from 3.3 to
1000 g/cm**2, respectively. Good agreement is found with previous measurements
for high momenta, while at momenta below 1 GeV/c we find latitude dependent
geomagnetic effects. These measurements are important cross-checks for the
simulations carried out to calculate the atmospheric neutrino fluxes and to
understand the observed atmospheric neutrino anomaly.Comment: 28 pages, 13 Postscript figures, uses revtex.sty, to appear in Phys.
Rev.
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