488 research outputs found
Economic effects analysis of public investment in road improvement works in Hokkaido. Simulation analysis based on a macro-econometric model of Hokkaido
The objective of this study is to clarify how public investment in road improvement projects over a given analytical period of time has affected Hokkaido`s economic structure on the whole in relation to the industrial economy, prefectural income, household consumption, and commodity prices, through a simulation analysis based on a macro-econometric model. More specifically, our goal is to model both the direct effects achieved through the use of improved roads including the reduction of time-distance coefficients, the reduction of transportation costs and market expansion, and the indirect effects such as enhancement of lifestyles and convenience and influence on other public projects including living area improvement and promotion of regional areas, and to identify these effects quantitatively. Taking data availability into consideration, this study covers a 21-year analysis period covering the years 1976 through 1996. In constructing a quantitative model, the effect flow to be modeled was examined from two perspectives: 1) an effect flow showing the effects of road improvement works on production efficiency and market efficiency; and 2) an effect flow showing the effects of road improvement works on living standards considering convenience and lifestyle improvement. Then we attempted building a model that could indicate the occurrence of these effects in both Flow and Stock contexts. As a result of the simulation analysis, it was clarified that application of road improvement works would bring about pronounced positive economic benefits in tertiary industries, particularly in the transportation-service and wholesale/retail sectors, and greatly expand the prefectural net product on the whole. It was also revealed that these expansion effects would stimulate an increase in the prefectural income and in private final consumption expenditure. Furthermore, a simulation analysis on the economic effects that the expansion of the express-highway network would have on Hokkaido`s entire economy revealed that there would be a large effect particularly on investment and production within the transportation/communication industry and also on the commercial output of the wholesale/retail industry.
Structure and superconducting properties of ((Ln(1-x)Ln*(x) 1/2 (Ba(1-y)Sr(y) 1/3 Ce 1/6) 8Cu6O(z)
A variety of new oxide superconductors were prepared. The crystallographic structures of the oxides were all tetragonal and of the (Ln(+), Ce)4(Ln(+),Ba)4Cu6Oz (Ln(+) = Nd, Sm or Eu) type which had been previously discovered by Akimitsu et al. As the Sr content, y, increased when Ln = Ln(excited state) = Nd, the oxygen content, z, monotonically increased and the superconducting transition temperature, T(sub c), varied exhibiting a maximum. When z was controlled directly by means of high oxygen pressure sintering techniques, T(sub c) was changed accordingly. T(sub c's) of samples with different combinations of Ln and Ln(excited state) and different values of x and y were found to depend on the magnitude of the bond valence sum for a Cu atom located in the bottom plane of the Cu-O5 pyramid. Transport and magnetization measurements were carried out to investigate the magnetic field dependence of superconducting properties and to determine the phenomenological parameters. The Hall coefficients were positive below room temperature and varied yielding a maximum with respect to temperature
Economic effects analysis of public investment in road improvement works in Hokkaido. Simulation analysis based on a macro-econometric model of Hokkaido
The objective of this study is to clarify how public investment in road improvement projects over a given analytical period of time has affected Hokkaido`s economic structure on the whole in relation to the industrial economy, prefectural income, household consumption, and commodity prices, through a simulation analysis based on a macro-econometric model. More specifically, our goal is to model both the direct effects achieved through the use of improved roads including the reduction of time-distance coefficients, the reduction of transportation costs and market expansion, and the indirect effects such as enhancement of lifestyles and convenience and influence on other public projects including living area improvement and promotion of regional areas, and to identify these effects quantitatively. Taking data availability into consideration, this study covers a 21-year analysis period covering the years 1976 through 1996. In constructing a quantitative model, the effect flow to be modeled was examined from two perspectives: 1) an effect flow showing the effects of road improvement works on production efficiency and market efficiency; and 2) an effect flow showing the effects of road improvement works on living standards considering convenience and lifestyle improvement. Then we attempted building a model that could indicate the occurrence of these effects in both Flow and Stock contexts. As a result of the simulation analysis, it was clarified that application of road improvement works would bring about pronounced positive economic benefits in tertiary industries, particularly in the transportation-service and wholesale/retail sectors, and greatly expand the prefectural net product on the whole. It was also revealed that these expansion effects would stimulate an increase in the prefectural income and in private final consumption expenditure. Furthermore, a simulation analysis on the economic effects that the expansion of the express-highway network would have on Hokkaido`s entire economy revealed that there would be a large effect particularly on investment and production within the transportation/communication industry and also on the commercial output of the wholesale/retail industry
On the Approximability and Hardness of Minimum Topic Connected Overlay and Its Special Instances
In the context of designing a scalable overlay network to support
decentralized topic-based pub/sub communication, the Minimum Topic-Connected
Overlay problem (Min-TCO in short) has been investigated: Given a set of t
topics and a collection of n users together with the lists of topics they are
interested in, the aim is to connect these users to a network by a minimum
number of edges such that every graph induced by users interested in a common
topic is connected. It is known that Min-TCO is NP-hard and approximable within
O(log t) in polynomial time. In this paper, we further investigate the problem
and some of its special instances. We give various hardness results for
instances where the number of topics in which an user is interested in is
bounded by a constant, and also for the instances where the number of users
interested in a common topic is constant. For the latter case, we present a
first constant approximation algorithm. We also present some polynomial-time
algorithms for very restricted instances of Min-TCO.Comment: 20 page
ALMA 0.02"-resolution observations reveal HCN-abundance-enhanced counter-rotating and outflowing dense molecular gas at the NGC 1068 nucleus
We present ALMA ~0.02"-resolution observations of the nucleus of the nearby
(~14 Mpc) type-2 AGN NGC 1068 at HCN/HCO+/HNC J=3-2 lines, as well as at their
13C isotopologue and vibrationally excited lines, to scrutinize the
morphological/dynamical/chemical/physical properties of dense molecular gas in
the putative dusty molecular torus around a mass-accreting supermassive black
hole. We confirm almost east-west-oriented dense molecular gas emission both
morphologically and dynamically, which we regard as coming from the torus.
Bright emission is compact (<3 pc), and low-surface-brightness emission extends
out to 5-7 pc. These dense molecular gas properties are not symmetric between
the eastern and western torus. The HCN J=3-2 emission is stronger than the HCO+
J=3-2 emission within the ~7 pc torus region, with an estimated dense molecular
mass of (0.4-1.0)x10^6Msun. We interpret that HCN abundance is enhanced in the
torus. We detect signatures of outflowing dense molecular gas and a
vibrationally excited HCN J=3-2 line. Finally, we find that in the innermost
(<1 pc) part of the torus, the dense molecular line rotation velocity, relative
to the systemic velocity, is the opposite of that in the outer (>2 pc) part, in
both the eastern and western torus. We prefer a scenario of counter-rotating
dense molecular gas with innermost almost-Keplerian-rotation and outer slowly
rotating (far below Keplerian) components. Our high-spatial-resolution dense
molecular line data reveal that torus properties of NGC 1068 are much more
complicated than the simple axi-symmetrically rotating torus picture in the
classical AGN unification paradigm.Comment: 45 pages, 20 Figures. Accepted for publication in Ap
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