114,193 research outputs found

### On cost-effective communication network designing

How to efficiently design a communication network is a paramount task for
network designing and engineering. It is, however, not a single objective
optimization process as perceived by most previous researches, i.e., to
maximize its transmission capacity, but a multi-objective optimization process,
with lowering its cost to be another important objective. These two objectives
are often contradictive in that optimizing one objective may deteriorate the
other. After a deep investigation of the impact that network topology, node
capability scheme and routing algorithm as well as their interplays have on the
two objectives, this letter presents a systematic approach to achieve a
cost-effective design by carefully choosing the three designing aspects. Only
when routing algorithm and node capability scheme are elegantly chosen can
BA-like scale-free networks have the potential of achieving good tradeoff
between the two objectives. Random networks, on the other hand, have the
built-in character for a cost-effective design, especially when other aspects
cannot be determined beforehand.Comment: 6 pages, 4 figure

### Branching Ratio and CP Asymmetry of B_s \to K^*_0(1430)\pi Decays in the PQCD Approach

In the two-quark model supposition for $K_0^{*}(1430)$, the branching ratios
and the direct CP-violating asymmetries for decays $\bar B_s^0\to
K^{*0}_0(1430)\pi^0, K^{*+}_0(1430)\pi^-$ are studied by employing the
perturbative QCD factorization approach. We find that although these two decays
are both tree-dominated, the ratio of their penguin to tree contributions are
very different: there is only a few percent for the decay $\bar B_s^0\to
K^{*+}_0(1430)\pi^-$, while about 37% in scenario I, even 51% in scenario II
for the decay $\bar B_s^0\to K^{*0}_0(1430)\pi^0$. It results that these two
decays have very different values in the branching ratios and the direct CP
asymmetries. The branching ratio of the decay $\bar B_s^0\to
K^{*+}_0(1430)\pi^-$ is at the order of $10^{-5}$, and its direct CP asymmetry
is about (20-30)%. While for the decay $\bar B_s^0\to K^{*0}_0(1430)\pi^0$, its
direct CP-violating asymmetry is very large and about 90%, but it is difficult
to measure it, because the branching ratio for this channel is small and only
$10^{-7}$ order.Comment: 8pages, 2figure

### Robust optimization for energy transactions in multi-microgrids under uncertainty

Independent operation of single microgrids (MGs) faces problems such as low self-consumption of local renewable energy, high operation cost and frequent power exchange with the grid. Interconnecting multiple MGs as a multi-microgrid (MMG) is an effective way to improve operational and economic performance. However, ensuring the optimal collaborative operation of a MMG is a challenging problem, especially under disturbances of intermittent renewable energy. In this paper, the economic and collaborative operation of MMGs is formulated as a unit commitment problem to describe the discrete characteristics of energy transaction combinations among MGs. A two-stage adaptive robust optimization based collaborative operation approach for a residential MMG is constructed to derive the scheduling scheme which minimizes the MMG operating cost under the worst realization of uncertain PV output. Transformed by its KKT optimality conditions, the reformulated model is efficiently solved by a column-and-constraint generation (C&CG) method. Case studies verify the effectiveness of the proposed model and evaluate the benefits of energy transactions in MMGs. The results show that the developed MMG operation approach is able to minimize the daily MMG operating cost while mitigating the disturbances of uncertainty in renewable energy sources. Compared to the non-interactive model, the proposed model can not only reduce the MMG operating cost but also mitigate the frequent energy interaction between the MMG and the grid

### Evaluation of the EMC environment generated by a static var compensator

Describes an evaluation of the EMC environment generated by a static var compensator

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