63 research outputs found
Achieving full diversity in multi-antenna two-way relay networks via symbol-based physical-layer network coding
No full textThis paper considers physical-layer network coding (PNC) with M-ary phase-shift keying (MPSK) modulation in two-way relay channel (TWRC). A low complexity detection technique, termed symbol-based PNC (SPNC), is proposed for the relay. In particular, attributing to the outer product operation imposed on the superposed MPSK signals at the relay, SPNC obtains the network-coded symbol (NCS) straightforwardly without having to detect individual symbols separately. Unlike the optimal multi-user detector (MUD) which searches over the combinations of all users’ modulation constellations, SPNC searches over only one modulation constellation, thus simplifies the NCS detection. Despite the reduced complexity, SPNC achieves full diversity in multi-antenna relay as the optimal MUD does. Specifically, antenna selection based SPNC (AS-SPNC) scheme and signal combining based SPNC (SC-SPNC) scheme are proposed. Our analysis of these two schemes not only confirms their full diversity performance, but also implies when SPNC is applied in multi-antenna relay, TWRC can be viewed as an effective single-input multiple-output (SIMO) system, in which AS-PNC and SC-PNC are equivalent to the general AS scheme and the maximal-ratio combining (MRC) scheme. Moreover, an asymptotic analysis of symbol error rate (SER) is provided for SC-PNC considering the case that the number of relay antennas is sufficiently large
Refrigerated container parks typical case of electrical systems with structured distributed loads
No full textA comprehensive design of an electrical system has to ensure optimal performances in terms of operation, maintenance and safety. The paper discusses the design criteria of electrical systems for refrigerated container parks in port terminals, characterized by a uniform placement of the containers inside the racks' structure. The paper considers, as case study, the terminal container of Kaohsiung, Taiwan. The general design criterion of power systems is to structure the electrical distribution into two or more circuit levels adopting the barycentric approach, promoting modularity when possible, especially for the cases of uniform distributed loads (UDLs). The modularity allows to create mobile and easily deployable solutions that, in conjunction with a re-routable power network can significantly increase the overall availability that represents a crucial requirement considering the service continuity level of the reefers. The adoption of a barycentric distribution increases the overall optimization of the distribution system together with the appropriate voltage levels. This provides higher performances, while at the same time, reducing construction's costs. The authors therefore suggest, for the refrigerated container parks, the adoption of a main MV distribution together with a modular LV distribution, supplied by containerized mobile MV IL V transformer substations located in each rack
Rule of Algorithm in Lv Shi Chun Qiu: Lessons To Learn
No full textFor author(s) of Lv/Lü`s Spring and Autumn (Lv/LüShi ChunQiu, Lv/Lü`s Spring and Autumn, or The Spring and Autumn [Annals] of Mr. Lü), the world works on fixed, mechanical laws, and moral laws has no real existence or certain power. Human beings thus exist for existence`s own sake, and should not let moral considerations hinder the consolidation of their existence. As passive existence of hermits could not be adequately consolidated, and men`s natural freedom of will is not safe from manipulation and deprivation by others, with knowledge of laws regarding human behaviour, effective consolidation of one`s existence calls for both un-distracted will without moral regard, and knowledge of laws ruling the world. In a world of established kingdoms warring each other, such will and knowledge further calls political power, or man and material power, to actually consolidate the existence of a human being, so such human being must be a king. Though even an all-knowing king would not be able to command everyone and everything he owns, solely with own mental and physical abilities, consolidation of his existence is still possible according to Lv Buwei (Lü Buwei, Lü Pu-wei), as the world will produce as a rule “noble” persons, who has knowledge of the world`s laws, but still could be reliably employed by kings by correct methods with their mysterious, almost mechanical loyalist tendency, in order to use all other subjects and natural resources in the domain. Actually, what Lv/Lü Buwei proposes is actually constructing a automatic machine, with the “noble” ministers acting as computers of artificial intelligence, and commoners as powerplant or working bits, to realize an algorithm formulated according to laws of the world, for consolidation of the king`s existence. With such machine, the king would be able to exist Singularly, in all possible security and happiness, without any own effort, nor reliance or fear of any other person. As all other biological human beings that used to be persons in ethical sense, has been subdued, and reduced to a new status as parts of the automatic machine, thus are no longer persons with comparable ethical standing to the king, and can as a result, no longer challenge or argue on the king`s eligibility of Singular, consolidated existence. If, extrapolating with Lv/Lü Buwei`s logic, this machine could one day no longer use biological human as parts, without compromising robustness, then it could be in order to destroy all such humans other than the king, as even complete subdual could not eliminate the natural tendency for consolidation of own existence in them. Such a plan, cruel as it can be in the eyes of spectators, could very possibly be not only approved by the king, but also his subjects, who has for many generations willing, and even eager, to sacrifice themselves and others for the king`s need of lavishness, and thus appear “justified”. Furthermore, though the rule of algorithm is never fully deployed in Lv/Lü Buwei`s time, it is not impossibly for it to revive and take hold in future, among warring capitalist “national states”, aided by technologies of another time
Short-Circuit Calculations in LV Cold Ironing Systems: Characteristic Currents Method CCM and IEC Method
No full textThis paper presents the calculation procedure of short
circuits adopting the CCM “Characteristic Currents Method”.
In a previous paper by the author Parise, the CCM has been
upgraded with the introduction of "characteristic"
countercurrents and the generalization of the Kirchhoff laws.
For illustrating the calculation procedure, the selected case study
deals with a low voltage cold ironing system where multiple ships
are allowed to operate simultaneously on one shore power
transformer and, so, a comparison has been developed between
the IEC approach of the short-circuit calculation and the CCM
New source for L-iditol and taxanes
No full textWe describe the first report of the recovery of L-iditol and Taxane from an angiosperm- Yunnanopilia longistaminata (W.Z.Li) C.Y.Wu et D.Z.Li (Opiliaceae). Two taxane compounds and L-iditol were isolated from the tender burgeon of Yunnanopilia longistaminata, and their structure were identified as Taxayunnansin B, Taxumairol E and L-iditol on the basis of NMR and MS spectrum, respectively. It is a new plant source for L-iditol and taxanes
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