Let G σ be an oriented graph of a simple undirected graph G with an orientation σ , which assigns to each edge of G a direction so that the resultant graph G σ becomes a directed graph. The skew energy of G σ is defined as the sum of the absolute values of all eigenvalues of the skew-adjacency matrix of G σ . Denote by U σ (2k) the set of all oriented unicyclic graphs on 2k vertices with a perfect matching which contain no cycle of length l with l ≡ 2(mod 4). In this paper, we characterize the oriented graphs of U σ (2k) with the minimal skew energy for k ≥ 4. MSC: 05C50; 15A30
The frequency speed control system in flow control based on SENLAN SB60 frequency converter is made up of input set value and actual value which is the feedback voltage signal given by flow sensor, then adjusted by process PID automatic control, changes output frequency to regulate the speed of three-phase asynchronous motor to achieve the purpose of speed regulation, thus the tank's flow control can be obtained.
In view of current production technology of asphalt concrete mixing plant and technology, a distributed computer control system based on PLC and field bus is developed. The compensation iteration self-learning algorithm is adopted, the compensation amount of learning algorithm of the system is designed and the course program control algorithm is presented. Therefore the precision of the system’s measurement and control is improved and the transmission error is reduced.
The energy of a graph is defined as the sum of the absolute values of the eigenvalues of its adjacency matrix. In this paper, we present a new technique to compare the energies of two bipartite graphs whose characteristic polynomials satisfy a given recurrence relation. As its applications, we can characterize the bipartite unicyclic graphs of order n with maximal, second-maximal, and third-maximal energy for n ≥ 27, and thus confirm the validity of the results in (Gutman et al. MATCH Commun Math Comput Chem 58:75-82, 2007) which were obtained by numerical calculations.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.