2,315 research outputs found
Categorial mirror symmetry for K3 surfaces
We study the structure of a modified Fukaya category
associated with a K3 surface , and prove that whenever is an elliptic K3
surface with a section, the derived category of \fF(X) is equivalent to a
subcategory of the derived category of coherent sheaves on
the mirror K3 surface .Comment: 11 pages, AmsLatex. Exposition (hopefully) improved, one argument
simplifie
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Of impacts, agents, and functions: An interdisciplinary meta-review of smart home energy management systems research
Smart home energy management technologies (SHEMS) have long been viewed as a promising opportunity to manage the way households use energy. Research on this topic has emerged across a variety of disciplines, focusing on different pieces of the SHEMS puzzle without offering a holistic vision of how these technologies and their users will influence home energy use moving forward. This paper presents the results of a systematic, interdisciplinary meta-review of SHEMS literature, assessing the extent to which it discusses the role of various SHEMS components in driving energy benefits. Results reveal a bias towards technical perspectives and controls approaches that seek to drive energy impacts such as load management and energy savings through SHEMS without user or third-party participation. Not only are techno-centric approaches more common, there is also a lack of integration of these approaches with user-centric, information-based solutions for driving energy impacts. These results suggest future work should investigate more holistic solutions for optimal impacts on household energy use. We hope these results will provoke a broader discussion about how to advance research on SHEMS to capitalize on their potential contributions to demand-side management initiatives moving forward
Quantum random number generation for 1.25 GHz quantum key distribution systems
Security proofs of quantum key distribution (QKD) systems usually assume that
the users have access to source of perfect randomness. State-of-the-art QKD
systems run at frequencies in the GHz range, requiring a sustained GHz rate of
generation and acquisition of quantum random numbers. In this paper we
demonstrate such a high speed random number generator. The entropy source is
based on amplified spontaneous emission from an erbium-doped fibre, which is
directly acquired using a standard small form-factor pluggable (SFP) module.
The module connects to the Field Programmable Gate Array (FPGA) of a QKD
system. A real-time randomness extractor is implemented in the FPGA and
achieves a sustained rate of 1.25 Gbps of provably random bits.Comment: 6 pages, 8 figure
Error analysis in a hate speech detection task: The case of Haspeede-TW at Evalita 2018
Taking as a case study the Hate Speech Detection task at EVALITA 2018, the paper discusses the distribution and typology of the errors made by the five best-scoring systems. The focus is on the sub-task where Twitter data was used both for training and testing (HaSpeeDe-TW). In order to highlight the complexity of hate speech and the reasons beyond the failures in its automatic detection, the annotation provided for the task is enriched with orthogonal categories annotated in the original reference corpus, such as aggressiveness, offensiveness, irony and the presence of stereotypes
Absolute frequency measurements of 85Rb nF7/2 Rydberg states using purely optical detection
A three-step laser excitation scheme is used to make absolute frequency
measurements of highly excited nF7/2 Rydberg states in 85Rb for principal
quantum numbers n=33-100. This work demonstrates the first absolute frequency
measurements of rubidium Rydberg levels using a purely optical detection
scheme. The Rydberg states are excited in a heated Rb vapour cell and Doppler
free signals are detected via purely optical means. All of the frequency
measurements are made using a wavemeter which is calibrated against a GPS
disciplined self-referenced optical frequency comb. We find that the measured
levels have a very high frequency stability, and are especially robust to
electric fields. The apparatus has allowed measurements of the states to an
accuracy of 8.0MHz. The new measurements are analysed by extracting the
modified Rydberg-Ritz series parameters.Comment: 12 pages, 5 figures, submitted to New. J. Phy
Interoperability Building Information Modeling and acoustical analysis software - A demonstration of a performing arts hall design process
By sharing and managing the database for a building model, Building Information Modeling (BIM) facilitates the design process at less cost. Some of BIM software has capabilities for acoustical analysis, but it is limited to noise level demonstration of MEP system in a building. Sophisticated acoustical analysis programs, such as EASE and CATT provide the useful parameters to determine the sound quality of a space with graphs, A/V systems, material database, and auralization. This research explores how BIM with discipline-specific data reinforced with acoustical information will be beneficial to both architects and acousticians, by allowing them to communicate efficiently. The design process for a performing arts hall is used to demonstrate how to interoperate between BIM system and acoustical analysis programs. Revit Architecture and EASE program are used as design and analysis tools for the project. A model is developed to improve the process of embedding acoustic information in BIM and sharing knowledge in an integrated delivery process
A rate splitting strategy for mitigating intra-cell pilot contamination in massive mimo
The spectral efficiency (SE) of Massive MIMO (MaMIMO) systems is affected by low quality channel estimates. Rate-Splitting (RS) has recently gained some interest in multiuser multiple antenna systems as an effective means to mitigate the multi-user interference due to imperfect channel state information. This paper investigates the benefits of RS in the downlink of a single-cell MaMIMO system when all the users use the same pilot sequence for channel estimation. Novel expressions for the SE achieved in the downlink by a single-layer RS strategy (that relies on a single successive interference cancellation at each user side) are derived and used to design precoding schemes and power allocation strategies for common and private messages. Numerical results are used to show that the proposed RS solution achieves higher spectral efficiency that conventional MaMIMO with maximum ratio precoding
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