228 research outputs found
Experiments Validating the Effectiveness of Multi-point Wireless Energy Transmission with Carrier Shift Diversity
This paper presents a method to seamlessly extend the coverage of energy
supply field for wireless sensor networks in order to free sensors from wires
and batteries, where the multi-point scheme is employed to overcome path-loss
attenuation, while the carrier shift diversity is introduced to mitigate the
effect of interference between multiple wave sources. As we focus on the energy
transmission part, sensor or communication schemes are out of scope of this
paper. To verify the effectiveness of the proposed wireless energy
transmission, this paper conducts indoor experiments in which we compare the
power distribution and the coverage performance of different energy
transmission schemes including conventional single-point, simple multi-point
and our proposed multi-point scheme. To easily observe the effect of the
standing-wave caused by multipath and interference between multiple wave
sources, 3D measurements are performed in an empty room. The results of our
experiments together with those of a simulation that assumes a similar antenna
setting in free space environment show that the coverage of single-point and
multi-point wireless energy transmission without carrier shift diversity are
limited by path-loss, standing-wave created by multipath and interference
between multiple wave sources. On the other hand, the proposed scheme can
overcome power attenuation due to the path-loss as well as the effect of
standing-wave created by multipath and interference between multiple wave
sources.Comment: This paper is submitted to IEICE IEICE Transactions on
Communications.
CHARACTERIZATION OF CARBONATED STEELMAKING SLAG AND ITS POTENTIAL APPLICATION IN CONSTRUCTION
In the current context of Vietnam, the solid waste of steel slag occupy ground for dumping and lead to severe environmental issue due to their high content of heavy metal and fine dust. For the purpose of large-scale recycling steel slag, up to now one of the most relevant solutions is to use as aggregate for asphaltic and/or cement concrete. In this paper, we aim to analyze the influence of the accelerated carbonation condition in the laboratory on the physio-chemical properties of carbonated steel slag. Materials composition were characterized by using different analysis techniques of XRD, SEM, TG and others measurement of the physio-properties (density, L.O.I..) were also realized with regards to the requirement of the national standard for concrete aggregate. In conclusion, we will discuss the effect of reaction condition and on the feasibility of implementing this specific treatment method on a larger scale.Keywords: steelmaking slag, solid waste, CO2 sequestration, accelerated carbonation, concrete aggregate
ViHOS: Hate Speech Spans Detection for Vietnamese
The rise in hateful and offensive language directed at other users is one of
the adverse side effects of the increased use of social networking platforms.
This could make it difficult for human moderators to review tagged comments
filtered by classification systems. To help address this issue, we present the
ViHOS (Vietnamese Hate and Offensive Spans) dataset, the first human-annotated
corpus containing 26k spans on 11k comments. We also provide definitions of
hateful and offensive spans in Vietnamese comments as well as detailed
annotation guidelines. Besides, we conduct experiments with various
state-of-the-art models. Specifically, XLM-R achieved the best
F1-scores in Single span detection and All spans detection, while
PhoBERT obtained the highest in Multiple spans detection. Finally,
our error analysis demonstrates the difficulties in detecting specific types of
spans in our data for future research.
Disclaimer: This paper contains real comments that could be considered
profane, offensive, or abusive.Comment: EACL 202
Millimeter-wave Evolution for 5G Cellular Networks
Triggered by the explosion of mobile traffic, 5G (5th Generation) cellular
network requires evolution to increase the system rate 1000 times higher than
the current systems in 10 years. Motivated by this common problem, there are
several studies to integrate mm-wave access into current cellular networks as
multi-band heterogeneous networks to exploit the ultra-wideband aspect of the
mm-wave band. The authors of this paper have proposed comprehensive
architecture of cellular networks with mm-wave access, where mm-wave small cell
basestations and a conventional macro basestation are connected to
Centralized-RAN (C-RAN) to effectively operate the system by enabling power
efficient seamless handover as well as centralized resource control including
dynamic cell structuring to match the limited coverage of mm-wave access with
high traffic user locations via user-plane/control-plane splitting. In this
paper, to prove the effectiveness of the proposed 5G cellular networks with
mm-wave access, system level simulation is conducted by introducing an expected
future traffic model, a measurement based mm-wave propagation model, and a
centralized cell association algorithm by exploiting the C-RAN architecture.
The numerical results show the effectiveness of the proposed network to realize
1000 times higher system rate than the current network in 10 years which is not
achieved by the small cells using commonly considered 3.5 GHz band.
Furthermore, the paper also gives latest status of mm-wave devices and
regulations to show the feasibility of using mm-wave in the 5G systems.Comment: 17 pages, 12 figures, accepted to be published in IEICE Transactions
on Communications. (Mar. 2015
Impact of sand mining on sediment transport and morphological change of Hai Phong coastal area
The paper presents the results of simulating the impact of sand mining on sediment transport and morphological change in Hai Phong coastal area based on Delft3D model. Scenario groups are established: Present scenarios without sand mining and simulated scenarios of the present sand mining (assuming 30% sand compared to plan). The scenario groups are calculated in the dry and rainy seasons for main wind directions (NE, SE, SW) in the case of moderate wind and strong wind. The results show that sand mining reduces sediment flow alongshore (2–81%) and seawards (5–83%). Besides, the increase in depth causes morphological change in this area: Rising the deposition rate (5–10 mm/month) at the sand mining locations; decreasing accretion rate and increasing the erosion rate in the neighboring areas of sand mining location
ANTI-SWAY TRACKING CONTROL OF OVERHEAD CRANE SYSTEM BASED ON PID AND FUZZY SLIDING MODE CONTROL
The paper presents a PID – Fuzzy Sliding Mode control (PID-FSMC) algorithm for overhead crane system to guarantee anti-sway trajectory tracking of the nominal plant. The proposed PID-FSMC law guarantees the closed-loop asymptotical stability as well as improveS the transient response of the load sway dynamics when the trolley is moving. The simulation results confirm the propriety of the proposed controller and show great promise of the controller application in practice
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