6,973 research outputs found
Pricing Limited Partnerships in the Secondary Market
This study investigates the pattern of prices for multiple partnerships sold in the secondary market. In the model, the partnership buyer prefers to purchase the units sequentially since sellers have varying desires to sell. The benefit of a sequential purchase strategy is partially offset by rational sellers who demand higher prices in earlier sales since the possibility of future sales reduces the sellersā eagerness to sell in earlier rounds. If this strategic component is sufficiently large, a pattern of decreasing prices should be observed. Using a panel dataset comprised of 52,679 transactions from eighteen real estate limited partnerships, and after controlling for performance characteristics, the study finds that prices decrease over time, thus indicating a significant strategic component in this market.
Numerical and Monte Carlo Bethe ansatz method: 1D Heisenberg model
In this paper we present two new numerical methods for studying thermodynamic
quantities of integrable models. As an example of the effectiveness of these
two approaches, results from numerical solutions of all sets of Bethe ansatz
equations, for small Heisenberg chains, and Monte Carlo simulations in
quasi-momentum space, for a relatively larger chains, are presented. Our
results agree with those obtained by thermodynamics Bethe ansatz (TBA) and
Quantum Transfer Matrix (QTM).Comment: 8 pages, 6 figure
Sustainable Growth and Ethics: a Study of Business Ethics in Vietnam Between Business Students and Working Adults
Sustainable growth is not only the ultimate goal of business corporations but also the primary target of local governments as well as regional and global economies. One of the cornerstones of sustainable growth is ethics. An ethical organizational culture provides support to achieve sustainable growth. Ethical leaders and employees have great potential for positive influence on decisions and behaviors that lead to sustainability. Ethical behavior, therefore, is expected of everyone in the modern workplace. As a result, companies devote many resources and training programs to make sure their employees live according to the high ethical standards. This study provides an analysis of Vietnamese business students’ level of ethical maturity based on gender, education, work experience, and ethics training. The results of data from 260 business students compared with 704 working adults in Vietnam demonstrate that students have a significantly higher level of ethical maturity. Furthermore, gender and work experience are significant factors in ethical maturity. While more educated respondents and those who had completed an ethics course did have a higher level of ethical maturity, the results were not statistically significant. Analysis of the results along with suggestions and implications are provided
Comparative experimental study of local mixing of active and passive scalars in turbulent thermal convection
We investigate experimentally the statistical properties of active and
passive scalar fields in turbulent Rayleigh-B\'{e}nard convection in water, at
. Both the local concentration of fluorescence dye and the local
temperature are measured near the sidewall of a rectangular cell. It is found
that, although they are advected by the same turbulent flow, the two scalars
distribute differently. This difference is twofold, i.e. both the quantities
themselves and their small-scale increments have different distributions. Our
results show that there is a certain buoyant scale based on time domain, i.e.
the Bolgiano time scale , above which buoyancy effects are significant.
Above , temperature is active and is found to be more intermittent than
concentration, which is passive. This suggests that the active scalar possesses
a higher level of intermittency in turbulent thermal convection. It is further
found that the mixing of both scalar fields are isotropic for scales larger
than even though buoyancy acts on the fluid in the vertical direction.
Below , temperature is passive and is found to be more anisotropic than
concentration. But this higher degree of anisotropy is attributed to the higher
diffusivity of temperature over that of concentration. From the simultaneous
measurements of temperature and concentration, it is shown that two scalars
have similar autocorrelation functions and there is a strong and positive
correlation between them.Comment: 13 pages and 12 figure
Fairness in Forecasting of Observations of Linear Dynamical Systems
In machine learning, training data often capture the behaviour of multiple
subgroups of some underlying human population. When the nature of training data
for subgroups are not controlled carefully, under-representation bias arises.
To counter this effect we introduce two natural notions of subgroup fairness
and instantaneous fairness to address such under-representation bias in
time-series forecasting problems. Here we show globally convergent methods for
the fairness-constrained learning problems using hierarchies of
convexifications of non-commutative polynomial optimisation problems. Our
empirical results on a biased data set motivated by insurance applications and
the well-known COMPAS data set demonstrate the efficacy of our methods. We also
show that by exploiting sparsity in the convexifications, we can reduce the run
time of our methods considerably.Comment: Journal version of Zhou et al. [arXiv:2006.07315, AAAI 2021
Apparatus and method for intra-layer modulation of the material deposition and assist beam and the multilayer structure produced therefrom
A method of producing a multilayer structure that has reduced interfacial roughness and interlayer mixing by using a physical-vapor deposition apparatus. In general the method includes forming a bottom layer having a first material wherein a first plurality of monolayers of the first material is deposited on an underlayer using a low incident adatom energy. Next, a second plurality of monolayers of the first material is deposited on top of the first plurality of monolayers of the first material using a high incident adatom energy. Thereafter, the method further includes forming a second layer having a second material wherein a first plurality of monolayers of the second material is deposited on the second plurality of monolayers of the first material using a low incident adatom energy. Next, a second plurality of monolayers of the second material is deposited on the first plurality of monolayers of the second material using a high incident adatom energy
Effects of different rhizosphere ventilation treatment on water and nutrients absorption of maize
The objective of this study was to explore the effects of different rhizosphere ventilation treatment on water and nutrients absorption of maize. The pot experiment was conducted using three methods: no ventilation, two day ventilation and four day ventilation, under conditions of the different levels of irrigation methods. As such, the influence of rhizosphere ventilation treatment on the physiological, water and nutrient absorption of maize was studied. Results showed that, with the increase inventilation frequency, plant height, leaf area and the content of chlorophyll in maize increased to a certain degree. Root activity of once in every four days ventilation was the biggest (8.237 mg/ (gĀ·h)), followed by that of once in every two days ventilation (6.171 mg/ (gĀ·h)), and that of no ventilation was the least (4.940 mg/ (gĀ·h)). Consequently, it increased by 66.7 and 29.9%, respectively. The chlorophyll content experimental results showed that, rhizosphere ventilation treatment does not affect transpiration of potted maize and has no significant difference on the irrigation water utilization rate.Key words: Potted maize, rhizosphere ventilation, water, nutrients absorption, agricultural water-saving
Isolation of Unknown Genes from Human Bone Marrow by Differental Screening and Single-Pass cDNA Sequences Determination
A cDNA sequencing project was initiated to characterize gene expression in human bone marrow and develop strategies to isolate novel genes. Forty-eight random cDNAs from total human bone marrow were subjected to single-pass DNA sequence analysis to determine a limited complexity of mRNAs expressed in the bone marrow. Overall, 8 cDNAs (17%) showed no similarity to known sequences. Information from DNA sequence analysis was used to develop a differential prescreen to subtract unwanted cDNAs and to enrich for unknown cDNAs. Forty-eight cDNAs that were negative with a complex probe were subject to single-pass DNA sequence determination. Of these prescreened cDNAs, the number of unknown sequences increased to 23 (48%). Unknown cDNAs were also characterized by RNA expression analysis using 25 different human leukemic cell lines. Of 13 unknown cDNAs tested, 10 were expressed in all cell types tested and 3 revealed a hematopoietic lineage-restricted expression pattern. Interestingly, while a total of only 96 bone marrow cDNAs were sequenced, 31 of these cDNAs represent sequences from unknown genes and 12 showed significant similarities to sequences in the data bases. One cDNA revealed a significant similarity to a serine/threonine-protein kinase at the amino acid level (56% identity for 123 amino acids) and may represent a previously unknown kinase. Differential screening techniques coupled with single-pass cDNA sequence analysis may prove to be a powerful and simple technique to examine developmental gene expression
Monte Carlo Simulation of HERD Calorimeter
The High Energy cosmic-Radiation Detection (HERD) facility onboard China's
Space Station is planned for operation starting around 2020 for about 10 years.
It is designed as a next generation space facility focused on indirect dark
matter search, precise cosmic ray spectrum and composition measurements up to
the knee energy, and high energy gamma-ray monitoring and survey. The
calorimeter plays an essential role in the main scientific objectives of HERD.
A 3-D cubic calorimeter filled with high granularity crystals as active
material is a very promising choice for the calorimeter. HERD is mainly
composed of a 3-D calorimeter (CALO) surrounded by silicon trackers (TK) from
all five sides except the bottom. CALO is made of 9261 cubes of LYSO crystals,
corresponding to about 55 radiation lengths and 3 nuclear interaction lengths,
respectively. Here the simulation results of the performance of CALO with
GEANT4 and FLUKA are presented: 1) the total absorption CALO and its absorption
depth for precise energy measurements (energy resolution: 1\% for electrons and
gamma-rays beyond 100 GeV, 20\% for protons from 100 GeV to 1 PeV); 2) its
granularity for particle identification (electron/proton separation power
better than ); 3) the homogenous geometry for detecting particles
arriving from every unblocked direction for large effective geometrical factor
(3 for electron and diffuse gamma-rays, 2 for cosmic ray nuclei); 4) expected observational results such
as gamma-ray line spectrum from dark matter annihilation and spectrum
measurement of various cosmic ray chemical components
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