317 research outputs found
A General Rate Duality of the MIMO Multiple Access Channel and the MIMO Broadcast Channel
We present a general rate duality between the multiple access channel (MAC)
and the broadcast channel (BC) which is applicable to systems with and without
nonlinear interference cancellation. Different to the state-of-the-art rate
duality with interference subtraction from Vishwanath et al., the proposed
duality is filter-based instead of covariance-based and exploits the arising
unitary degree of freedom to decorrelate every point-to-point link. Therefore,
it allows for noncooperative stream-wise decoding which reduces complexity and
latency. Moreover, the conversion from one domain to the other does not exhibit
any dependencies during its computation making it accessible to a parallel
implementation instead of a serial one. We additionally derive a rate duality
for systems with multi-antenna terminals when linear filtering without
interference (pre-)subtraction is applied and the different streams of a single
user are not treated as self-interference. Both dualities are based on a
framework already applied to a mean-square-error duality between the MAC and
the BC. Thanks to this novel rate duality, any rate-based optimization with
linear filtering in the BC can now be handled in the dual MAC where the arising
expressions lead to more efficient algorithmic solutions than in the BC due to
the alignment of the channel and precoder indices.Comment: Submitted to IEEE Globecom 2008; Fixed dimensions of channel matrix
H_k and covariance matrix Z_k, slightly modified conclusio
Concert recording 2015-03-05
[Track 01]. Three contrapuncti from The art of fugue BWV 1080. Contrapunctus I ; [Track 02]. Contrapunctus IV ; [Track 03]. Contrapunctus IX / Johann Sebastian Bach -- [Track 04]. Premier quatuor op. 53. Adagio-allegro ; [Track 05]. Adagio sostenuto ; [Track 06]. Allegro vivace ; [Track 07]. Allegretto / Jean Baptiste Singelee -- [Track 08]. Saxophone quartet. Molto moderato ; [Track 09]. Andantio giovale ; [Track 10]. Adagio-allegro molto ; [Track 11]. Recitatives ; Presto meccanico / Stephen Dankner
Perceived weight status and risk of weight gain across life in US and UK adults
Background: Correctly identifying oneself as being overweight is presumed to be a prerequisite to successful weight management. The present research examined the effect that perceiving oneself as being ‘overweight’ has on risk of future weight gain in US and UK adults. Methods: Data from three longitudinal studies; US National Longitudinal Study of Adolescent Health (Add Health) 2001/2002–2008/2009, UK National Child Development Study (NCDS) 1981–2002/2004, and Midlife in the United States (MIDUS) 1995/1996–2004/2005, were used to examine the impact of perceiving oneself as being overweight on weight gain across adulthood in over 14 000 US and UK adults. Results: Participants who perceived their weight status as being overweight were at an increased risk of subsequent weight gain. This effect was observed irrespective of weight status at baseline and whether weight status perceptions were accurate or inaccurate. In the MIDUS sample, perceiving oneself as being overweight was associated with overeating in response to stress and this mediated the relationship between perceived overweight and weight gain. Conclusions: Perceiving oneself as being ‘overweight’ is counter-intuitively associated with an increased risk of future weight gain among US and UK adults
Momentum distribution function and short-range correlations of the warm dense electron gas -- ab initio quantum Monte Carlo results
In a classical plasma the momentum distribution, , decays
exponentially, for large , and the same is observed for an ideal Fermi gas.
However, when quantum and correlation effects are relevant simultaneously, an
algebraic decay, has been predicted. This is of
relevance for cross sections and threshold processes in dense plasmas that
depend on the number of energetic particles. Here we present extensive
\textit{ab initio} results for the momentum distribution of the nonideal
uniform electron gas at warm dense matter conditions. Our results are based on
first principle fermionic path integral Monte Carlo (CPIMC) simulations and
clearly confirm the asymptotic. This asymptotic behavior is directly
linked to short-range correlations which are analyzed via the on-top pair
distribution function (on-top PDF), i.e. the PDF of electrons with opposite
spin. We present extensive results for the density and temperature dependence
of the on-top PDF and for the momentum distribution in the entire momentum
range
Mohs Micrographic Surgery for Cutaneous Squamous Cell Carcinoma.
BACKGROUND
The first-line treatment of the localized form of cutaneous squamous cell carcinoma (cSCC) remains surgical excision. Either conventional excision (CE) with margins or Mohs micrographic surgery (MMS) may be preferred, depending on the risk factors of cSCC, the characteristics of the tumor, and the available technical facilities.
METHODS
This article presents a systematic review of the current literature spanning from 1974 to 2023, comparing outcomes of cSCC treated with MMS versus cSCC treated with conventional excision.
RESULTS
Out of the 6821 records identified through the database search, a total of 156 studies were screened, of which 10 were included in the review. The majority of the included studies showed that treatment of cSCC with MMS consistently exhibits a significantly lower risk of recurrence compared to treatment with CE. In addition, MMS is emerging as the preferred technique for the resection of cSCC located in aesthetically or functionally challenging anatomical areas.
CONCLUSION
The studies generally demonstrate that MMS is a safer and more effective treatment of cSCC than CE. Nevertheless, outcomes such as recurrence rates and cost-effectiveness should be assessed more precisely, in order to allow for a more tailored approach in determining the appropriate indication for the use of MMS
On designing safe and flexible embedded DSLs with Java 5
AbstractAlthough embedded DSLs are widely used in both functional and dynamic languages they are yet to be widely accepted in the Java community. The best available examples are projects like jMock and Hibernate Criteria Query. In this paper we introduce the design of three novel practical embedded DSLs that we designed to showcase the power of Java language and specifically the changes introduced in Java 5. One of those DSLs is fully implemented as an open source project and is gathering momentum in the community. We proceed to discuss the approaches that allow designing safe and flexible DSLs by extracting generic patterns where possible and describing more specific idioms where necessary. It is our goal that this paper would serve as a starting point for someone designing an embedded DSL that takes full advantage of the Java 5 features
Fabrication and Characterization of Single-Crystal Diamond Membranes for Quantum Photonics with Tunable Microcavities
The development of quantum technologies is one of the big challenges in modern research. Acrucial component for many applications is an efficient, coherent spin–photon interface, and coupling single-color centers in thin diamond membranes to a microcavity is a promising approach. To structure such micrometer thin single-crystal diamond (SCD) membranes with a good quality, it is important to minimize defects originating from polishing or etching procedures. Here, we report on the fabrication of SCD membranes, with various diameters, exhibiting a low surface roughness down to 0.4 nm on a small area scale, by etching through a diamond bulk mask with angled holes. A significant reduction in pits induced by micromasking and polishing damages was accomplished by the application of
alternating Ar/Cl2 + O2 dry etching steps. By a variation of etching parameters regarding the Ar/Cl2 step, an enhanced planarization of the surface was obtained, in particular, for surfaces with a higher initial surface roughness of several nanometers. Furthermore, we present the successful bonding of
an SCD membrane via van der Waals forces on a cavity mirror and perform finesse measurements which yielded values between 500 and 5000, depending on the position and hence on the membranethickness. Our results are promising for, e.g., an efficient spin–photon interface
- …