On the Properties of Language Classes Defined by Bounded Reaction Automata

Reaction automata are a formal model that has been introduced to investigate the computing powers of interactive behaviors of biochemical reactions([14]). Reaction automata are language acceptors with multiset rewriting mechanism whose basic frameworks are based on reaction systems introduced in [4]. In this paper we continue the investigation of reaction automata with a focus on the formal language theoretic properties of subclasses of reaction automata, called linearbounded reaction automata (LRAs) and exponentially-bounded reaction automata (ERAs). Besides LRAs, we newly introduce an extended model (denoted by lambda-LRAs) by allowing lambda-moves in the accepting process of reaction, and investigate the closure properties of language classes accepted by both LRAs and lambda-LRAs. Further, we establish new relationships of language classes accepted by LRAs and by ERAs with the Chomsky hierarchy. The main results include the following : (i) the class of languages accepted by lambda-LRAs forms an AFL with additional closure properties, (ii) any recursively enumerable language can be expressed as a homomorphic image of a language accepted by an LRA, (iii) the class of languages accepted by ERAs coincides with the class of context-sensitive languages.Comment: 23 pages with 3 figure

The Selection of the Representative Year of Stream Flow for Electric Power Generation

An analysis of the actual state of the combination of the load and the hydro-and steam-power in a large combined hydro-steam power system is necessary for any economic comparison between various types of hydro- and steam-power generation; and for the power generation by a plant of the run-off-river type as well as of the pondage and storage types, it sometimes involves an inspection of the daily stream flow in connection with the daily load curve throughout a year. In such cases, it being difficult to draw a daily stream flow diagram for the future, it sometimes becomes necessary to select the representative year representing a typical stream flow from the data in the past. This paper describes the method for its selection

The Annual Average Stream Flow for Hydro-electric Power

In a large combined hydro-steam power system as in Japan, it is necessary to know what flowing condition of rivers may be expected to hold on an average for a long term, in order to plan for the economical development of hydro-power. However, the flowing condition not only varies in its total annual stream flow each year, but even seasonally within a given year, which makes it difficult for us to deal directly with the duration curves of stream flow or the daily stream flow curves which have been hitherto employed in developing hydro-power, so that we have to consider as a parameter the annual average stream flow for each year on which these depend. We need not take the average of all the data obtained in the past in order to estimate the annual average stream flow expected to hold for a long term to come, but must resort to the reasonable method of so-called time series analysis with its theoretical foundation, which takes into consideration the periodicity of the fluctuation contained in the stream flow and other factors. In this paper we propose to estimate the annual average stream flow expected to hold on an average for a considerably long term by means of an analysis, as easy and practical as possible, of a stream flow of comparatively small sample size

Reaction Automata

Reaction systems are a formal model that has been introduced to investigate the interactive behaviors of biochemical reactions. Based on the formal framework of reaction systems, we propose new computing models called reaction automata that feature (string) language acceptors with multiset manipulation as a computing mechanism, and show that reaction automata are computationally Turing universal. Further, some subclasses of reaction automata with space complexity are investigated and their language classes are compared to the ones in the Chomsky hierarchy.Comment: 19 pages, 6 figure

Estimation of the Average Stream Flow in the Immediate Future for Hydro-electric Power Generation

In making an economical study of a large combined hydro-steam power system, it is necessary to estimate the annual average available power of the rivers for any given year in the immediate future, and, especially for the control of a plant of pondage or storage type, to estimate the drought-seasonal average stream flow during the coming winter. In this paper we shall study the method for estimating the annual average stream flow by means of the theoretically based method of statistical extrapolation, and the method for estimating the drought-seasonal average stream flow during the coming winter by means of the method of statistical extrapolation for a time series with two members, by analysing the existing data of the seasonal average stream flows during winter and autumn over a number of recent years, including that for autumn of the estimated year, taking the data of certain rivers as examples

Turbid intrusion below the thermal staircase in the seasonal thermocline of Lake Biwa

Thermal 'staircase', a layer of constant temperature between the sheets of the steep gradients, was formed in the seasonal thermocline, which was 2.5 m above the bottom at a point of 18 m deep on the boundary slope in Lake Biwa. Following a sediment resuspension event when a moderate onshore wind blew, bed materials should be suspended up to the thermocline, then settled down forming a staircase above the turbid intrusion. Comparing the observed downward hear flux with the settling flux of sediment, it was found that double-diffusive convection would play an important role on the formation of the whole structure consisting of the staircase and turbid intrusion along with chemical anomalies and dense population of phytoplankters, which were fed by nutrients supplied from the bottom sediment under a typical condition of drought. Laboratory experiments were conducted to demonstrate the thermal and sediment processes in the stratified lake. Resuspension process due to surface and internal waves was examined using a tank with a sloping bottom, while the settling process was investigated by using a deep, diffusive tank. Formative process and scales of the staircase and intrusion were discussed relating with the intensity of resuspension and the buoyancy fluxes

{6,6′-Dimeth­oxy-2,2′-[o-phenyl­enebis(nitrilo­methyl­idyne)]diphenolato}cobalt(II) dichloro­methane disolvate

The title compound, [Co(C22H18N2O4)]·2CH2Cl2, was isolated from the reaction of N,N′(o-phenyl­ene)bis­(vanillalimine) (H2 L) with Co(SCN)2. The crystal structure contains a CoII ion surrounded by the L 2− ligand in a slightly distorted square-planar fashion. Inter­molecular C—H⋯O hydrogen-bonding contacts between the dichloro­methane solvent mol­ecules and the meth­oxy or carboxyl­ate O atoms are observed in the crystal structure. The planar complex mol­ecules stack through inversion related π–π inter­actions between the six-membered rings of the vanillalimine half ligands. The distance between centroids is 3.498 (2) Å and the perpendicular distance is 3.345 Å. A partial stacking is observed with a centroid–centroid distance of 3.830 (2) Å, a perpendicular distance of 3.350 Å and a slippage of 1.856 Å