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Number of results: 5
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Abstract

An approach is presented to form and broaden the low-frequency band gap of the double panel structure (DPS) by using a locally resonant sonic crystal (LRSC) in this work. The LRSC is made of cylindrical Helmholtz resonators arranged on square lattice. Their designs are similar to a slot-type resonator, but have different depths of slot. Elongating the slit neck inward and distributing the depths of slots produce a broad local resonant band gap at low frequencies: an average insertion loss (IL) of 10.9 dB covering 520 Hz to 1160 Hz with a LRSC of 12 cm width. Next, the effect of porous material filled into the resonators on the local resonant band gap is evaluated. It is shown that filling of porous material into the resonators decreases the height and width of the local resonant band gap. Finally, the transmission losses (TLs) through the DPS with LRSC are calculated as a function of the incident angle of the sound wave for LRSC embedded in porous material and not. The results show that the porous material can be significantly reduce the incident angle dependency of TL through the DPS with LRSC.
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Authors and Affiliations

Myong-Jin Kim
1
Chun-Gil Rim
1
Kyong-Su Won
1

  1. Institute of Acoustics, Department of Physics, Kim Il Sung University, Pyongyang, Democratic People’s Republic of Korea
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Abstract

Packet-switched xHaul networks are a scalable solution enabling convergent transport of diverse types of radio data flows, such as fronthaul / midhaul / backhaul (FH / MH / BH) flows, between remote sites and a central site (hub) in 5G radio access networks (RANs). Such networks can be realized using the cost-efficient Ethernet technology, which enhanced with time-sensitive networking (TSN) features allows for prioritized transmission of latency-sensitive fronthaul flows. Provisioning of multiple types of 5G services of different service requirements in a shared network, commonly referred to as network slicing, requires adequate handling of transported data flows in order to satisfy particular service / slice requirements. In this work, we investigate two traffic prioritization policies, namely, flowaware (FA) and latency-aware (LA), in a packet-switched xHaul network supporting slices of different latency requirements. We evaluate the effectiveness of the policies in a networkplanning case study, where virtualized radio processing resources allocated at the processing pool (PP) facilities, for two slices related to enhanced mobile broadband (eMBB) and ultra-reliable low latency communications (URLLC) services, are subject to optimization. Using numerical experiments, we analyze PP cost savings from applying the LA policy (vs. FA) in various network scenarios. The savings in active PPs reach up to 40% − 60% in ring scenarios and 30% in a mesh network, whereas the gains in overall PP cost are up to 20% for the cost values assumed in the analysis.
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Authors and Affiliations

Mirosław Klinkowski
1

  1. National Institute of Telecommunications, Warsaw, Poland
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Abstract

In this paper an artificial neural network, which realizes a nonlinear adaptive control algorithm, has been applied in a control system of variable speed generating system. The speed is adjusted automatically as a function of load power demand. The controller employs a single layer neural network to estimate the unknown plant nonlinearities online. Optimization of the controller is difficult because the plant is nonlinear and no stationary. Furthermore, it deals with the situation where the plant becomes uncontrollable without any restrictive assumptions. In contrast to previous work [1] on the same subject, the number of neural networks has been reduced to only one network. The number of the neurons in a network structure as well as choosing certain design parameters was specified a priori. The computer test results have been presented to show performance of proposed neural controller.

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Authors and Affiliations

L.M. Grzesiak
J. Sobolewski
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Abstract

Patristic exegesis followed certain hermeneutical rules different from the modern principles of scientific interpretation of the Scripture. The main feature was christocentrism: Jesus Christ was the first hermeneutical key to understand the Bible. The second principle is the unity of the Scripture: the Old Testament is read and interpreted in the light of the New Testament. The third characteristic is the twofold way of reading the Word of God: literal and spiritual; both are complementary and need each other to achieve the full comprehension of the biblical message. The fourth is typology and symbolism: each literary motif of the Scripture (person, thing, event, etc.) can be a carrier of many meanings useful for spiritual purposes, exceeding the historical context. A special attention is attributed also to the tradition of the Church, the Eucharistic perspective and the fact that Church Fathers and ancient Rabbis interpreted and explained the Old Testament in the contexts of their communities of faith, independently but sometimes following similar intuitions.
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Authors and Affiliations

Krzysztof Bardski

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