2,440 research outputs found
Compensation and price delegation for heterogeneous sales force
A heterogeneous sales force may not be as desirable as a homogeneous sales force for two reasons: premiums are required for all except from one agent type, and only the highest type would work as hard as though they were from a homogeneous sales force. This study revisits the heterogeneous sales force compensation and price delegation problem with type-dependent reservation. We find that an equilibrium separating or pooling compensation contract always exists. Different types of agents may receive premiums, and there are scenarios when no premiums are paid. Retaining centralized pricing provides a tool for regulating agent behavior. More than one or even all agent types may work as hard as though they were members of a homogeneous sales force. These findings differ from existing results and their driving force is the dynamics between the differences in reservations and agents’ effort costs arising from concealing their true types
Generalized integrated importance measure for system performance evaluation: application to a propeller plane system
The integrated importance measure (IIM) evaluates the rate of system performance change due to a component changing from one state to another. The IIM simply considers the scenarios where the transition rate of a component from one state to another is constant. This may contradict the assumption of the degradation, based on which system performance is degrading and therefore the transition rate may be increasing over time. The Weibull distribution describes the life of a component, which has been used in many different engineering applications to model complex data sets. This paper extends the IIM to a new importance measure that considers the scenarios where the transition rate of a component degrading from one state to another is a time-dependent function under the Weibull distribution. It considers the conditional probability distribution of a component sojourning at a state is the Weibull distribution, given the next state that component will jump to. The research on the new importance measure can identify the most important component during three different time periods of the system lifetime, which is corresponding to the characteristics of Weibull distributions. For illustration, the paper then derives some probabilistic properties and applies the extended importance measure to a real-world example (i.e., a propeller plane system)
Investigation of suppressor of overexpression of constans 1 (SOC1) function in flowering time control of Arabidopsis thaliana
Master'sMASTER OF SCIENC
The role of adipose-derived stem cells-derived extracellular vesicles in the treatment of diabetic foot ulcer: Trends and prospects
Diabetic foot ulcer(DFU) is one of the most severe chronic complications of type 2 diabetes mellitus, which is mainly caused by peripheral vascular occlusion with various degrees of infection. Treatment of DFU is difficult, and ulcer formation in lower limbs and deep-tissue necrosis might lead to disability or even death. Insulin resistance is the major mechanism of type 2 diabetes mellitus development, largely caused by adipose tissue dysfunction. However, adipose tissue was recently identified as an important endocrine organ that secretes bio-active factors, such as adipokines and extracellular vesicles(EVs). And adipose tissue-derived stem cells(ADSCs) are abundant in adipose tissue and have become a hot topic in the tissue engineering field. In particular, EVs derived from ADSCs contain abundant biomarkers and mediators. These EVs exert significant effects on distant cells and organs, contributing to metabolic homeostasis. In this review, we aim to elaborate on the mechanisms of diabetic non-healing wound development and the role of ADSCs-EVs in wound repair, which might provide a new therapy for treating DFU
Assessing Moisture Content on the Surface of Mortar Samples from Hyperspectral Imaging
Hyperspectral imaging represents an electromagnetic spectrum for each pixel in the image of a structural surface. The characteristic wavelength of the spectrum at reflectance valleys or absorption peaks can be used as a spectral feature for certain chemical detection. In this study, spectral reflectance characteristics of mortar samples are extracted to assess the reduction of moisture on the surface of mortar samples during the cement hydration process. The test results indicate that the reflectance increases and the absorbance decreases because water is reacted and less light will be absorbed during the hydration process. The average absorbance between 1923 nm and 1983 nm in wavelength gradually decreases with the mortar curing time. This feature parameter can be used to evaluate the mortar hydration process
The Radio Properties of Radio-Loud Narrow-Line Seyfert 1 Galaxies on Parsec Scales
We present the detection of compact radio structures of fourteen radio-loud
narrow line Seyfert 1 (NLS1) galaxies from Very Long Baseline Array
observations at 5 GHz, which were performed in 2013. While 50\% of the sources
of our sample show a compact core only, the remaining 50\% exhibit a core-jet
structure. The measured brightness temperatures of the cores range from
to K with a median value of K, indicating
that the radio emission is from non-thermal jets, and that, likely, most
sources are not strongly beamed, then implying a lower jet speed in these
radio-loud NLS1 galaxies. In combination with archival data taken at multiple
frequencies, we find that seven sources show flat or even inverted radio
spectra, while steep spectra are revealed in the remaining seven objects.
Although all these sources are very radio-loud with , their jet
properties are diverse, in terms of their milli-arcsecond (mas) scale (pc
scale) morphology and their overall radio spectral shape. The evidence for slow
jet speeds (i.e., less relativistic jets), in combination with the low
kinetic/radio power, may offer an explanation for the compact VLBA radio
structure in most sources. The mildly relativistic jets in these high accretion
rate systems are consistent with a scenario, where jets are accelerated from
the hot corona above the disk by the magnetic field and the radiation force of
the accretion disk. Alternatively, a low jet bulk velocity can be explained by
low spin in the Blandford-Znajek mechanism.Comment: 39 pages, 17 figures, ApJS accepte
Development And Characterization Of Coal-Based Thermoplastic Composite Material For Sustainable Construction
The exploitation of coal and the disposal of waste plastic present significant environmental and economic challenges that require sustainable and profitable solutions. In response, we propose a renewable construction composite material of coal-based thermoplastic composite (CTC) that can be made from low-grade coal and plastic waste. We developed and tested the hot-press fabrication method for this CTC, using coal with a maximum particle size of 4.75 mm and recycled high-density polyethylene (HDPE). The effects of the coal fraction (50–80 wt.%) on compressive properties, thermal properties, microstructure, and ecological and economic efficiencies of the CTC were investigated. Test results revealed that the compressive strength and modulus decrease as the coal fraction increases. However, the thermal properties, including thermal conductivity and specific heat, increase with higher coal contents. Compared to concrete, the CTC has about half the thermal conductivity and twice the specific heat, making it a more energy-efficient construction material. Microstructure testing helped to reveal the mechanisms behind the above behaviors of CTC from the observation of binder volume, bonding quality between coal and HDPE, and porosity variation. The life cycle analysis indicated that the CTC production reduced embodied energy, carbon footprint, and cost by up to 84%, 73%, and 14%, respectively. Therefore, we recommend the CTC with 50–70% coal fraction as an innovative construction material with satisfied mechanical and thermal properties, better cost efficiency, and a reduced ecological impact
Time Variation of Fine-Structure Constant Constrained by [O III] Emission-Lines at 1.1<z<3.7
[O III]4960,5008 doublet are often the strongest narrow
emission lines in starburst galaxies and quasi-stellar objects (QSOs), and thus
are a promising probe to possible variation of the fine-structure constant
over cosmic time. Previous such studies using QSOs optical spectra
were limited to . In this work, we constructed a sample of 40 spectra of
Ly emitting galaxies (LAEs) and a sample of 46 spectra of QSOs at
using the VLT/X-Shooter near-infrared spectra publicly available.
We measured the wavelength ratios of the two components of the spin-orbit
doublet and accordingly calculated using two methods. Analysis on
all of the 86 spectra yielded with
respect to the laboratory measurements, consistent with no variation
over the explored time interval. If assuming a uniform variation rate, we
obtained yr
within the last 12 Gyrs. Extensive tests indicate that variation could
be better constrained using starburst galaxies' spectra than using QSO spectra
in future studies.Comment: 24 pages, 22 figures. Accepted for publication in MNRA
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