A Simple Proof of the Classification of Normal Toeplitz Matrices

We give an easy proof to show that every complex normal Toeplitz matrix is classified as either of type I or of type II. Instead of difference equations on elements in the matrix used in past studies, polynomial equations with coefficients of elements are used. In a similar fashion, we show that a real normal Toeplitz matrix must be one of four types: symmetric, skew-symmetric, circulant, or skew-circulant. Here we use trigonometric polynomials in the complex case and algebraic polynomials in the real case.Comment: 5 page

Impact of land readjustment project on farmland use and structural adjustment: The case of Niigata, Japan

This paper examines the impact of farmland readjustment projects on farmland use and structural adjustment in Niigata, Japan. We use census data of rural communities for 1990 and 2000 to conduct pooled regression, first-difference, difference-in-differences, and propensity score matching estimations. We find positive impact of farmland readjustment projects in alleviating farmland abandonment and in facilitating outsourcing of agricultural works and farmland rental. The results suggest that farmland consolidation may be an effective option to resolve farmland fragmentation and to promote structural adjustment in concentrating farmland to efficient farmers which is a premise for strengthening the agricultural sector under economies of scale.land readjustment, consolidation, fragmentation, farmland rental, farmland abandonment, Japan, Land Economics/Use,

Participatory Rural Development in 1930s Japan: The Economic Rehabilitation Movement

This paper studies an early participatory rural development program implemented during the 1930s in Japan. This program selected several villages each year to draft and implement their own original development plans. I discuss the implications of the features of the program on its effectiveness. A detailed baseline survey conducted by the villagers themselves helped them to objectively diagnose their economic situations and understand their issues. The plans defined clear numerical targets, allowing them to share goals and monitor progress. The implementation of the plan was reinforced by frequent communication and monitoring among neighbors and by an incentive scheme that involved competition within a village. I use a village-level panel dataset from the Hyogo prefecture to examine the effects, under the difference-in-differences strategy. I find suggestive evidence that the program helped foster the adoption of cattle raising and diversify agricultural production.Participatory development, Rural development program, Crop diversification, Great Depression, Japan

The impact of farmland readjustment and consolidation on structural adjustment: The case of Niigata, Japan

Improving agricultural productivity is a pressing challenge for rapidly growing economies. Farmland concentration among core famers is instrumental for reaping the economies of scale. However, farmland fragmentation often serves as a barrier to such structural adjustments. This paper studies Farmland Improvement Projects in Japan, which physically mitigate farmland fragmentation by merging and enlarging small plots and consolidating land parcels among farmers. I employ community-level panel data to make use of difference-in-differences matching estimators, in order to measure the projects’ impacts. I find positive effects of the projects on structural adjustment, in the form of machinery-work outsourcing.farmland improvement project, farmland concentration, farmland fragmentation, structural adjustment, Japan

Age and Dust Degeneracy for Starburst Galaxies Solved?

A spectral evolution model of galaxies that includes both stellar and dust effects is newly built. xApplying the model to 22 nearby starburst galaxies, we have shown that far infrared luminosity of galaxies helps to break the age-dustiness degeneracy. We have derived a unique solution of age and the dustiness for each starburst galaxy. The resulting starburst ages and optical depths are in the range $10 \le t (Myr) \le 500$ and $0.5 \le \tau_{V} \le 5.0$, respectively. The result is robust and is almost independent of model assumptions such as dust distributions, extinction curves, and burst strengths. With the rapidly growing sensitivity of submillimeter detectors, it should become possible in the near future to determine the age and $\tau_{V}$ of star-forming galaxies at redshifts $z \simeq 3$ and beyond. Accurate estimates of $\tau_{V}$ for Lyman-break galaxies and high-z galaxies might require a substantial revision of the previously claimed picture of star formation history over the Hubble time.Comment: Latex (aas2pp4) 15 pages, 1 table, 6 figures. Accepted for Ap

Cosmological Gamma-Ray Bursts and Evolution of Galaxies

Evolution of the rate density of cosmological gamma-ray bursts (GRBs) is calculated and compared to the BATSE brightness distribution in the context of binary neutron-star mergers as the source of GRBs, taking account of the realistic star formation history in the universe and evolution of compact binary systems. We tried two models of the evolution of cosmic star formation rate (SFR): one is based on recent observations of SFRs at high redshifts, while the other is based on a galaxy evolution model of stellar population synthesis that reproduces the present-day colors of galaxies. It is shown that the binary merger scenario of GRBs naturally results in the comoving rate-density evolution of \propto (1+z)^{2-2.5} up to z ~ 1, that has been suggested independently from the compatibility between the number-brightness distribution and duration-brightness correlation. If the cosmic SFR has its peak at z ~ 1--2 as suggested by recent observations, the effective power-index of GRB photon spectrum, \alpha >~ 1.5$ is favored, that is softer than the recent observational determination of \alpha = 1.1 \pm 0.3. However, high redshift starbursts (z >~ 5) in elliptical galaxies, that have not yet been detected, can alleviate this discrepancy. The redshift of GRB970508 is likely about 2, just below the upper limit that is recently determined, and the absorption system at z = 0.835 seems not to be the site of the GRB.Comment: ApJ Lett. in press, very minor change just making clear that the predicted rate-density evolution is in a comoving sense. (Received 1997 May 15; Accepted 1997 July 2

Developing Open Educational Resources through Learning Design and Agile Practices

One of the current challenges related to Open Educational Resources (OERs) is how to produce quality and relevant materials to be reused and adapted to different contexts and learning situations. In this paper we present a flexible and systematic method for OERs, called AM-OER, that allows the development of OERs to evolve incrementally, and be modified and improved as needed. Practices of Learning Design are incorporated into the OERs development, making the design more understandable and shareable, and facilitating the reuse and adaptation. We applied AM-OER through a case study involving the development of a course in the software engineering domain. The results obtained suggest the applicability and usefulness of the AM-OER in the development of OERs

A Robust Age Indicator for Old Stellar Populations

We derive new spectral H_gamma index definitions which are robust age indicators for old and relatively old stellar populations and thus have great potential for solving the age-metallicity degeneracy of galaxy spectra. To study H_gamma as a function of age, metallicity and resolution, we used a new spectral synthesis model which predicts SEDs of single-age, single-metallicity stellar populations at resolution FWHM=1.8A (which can be smoothed to different resolutions), allowing direct measurements of the equivalent widths of particular absorption features. We find that the H_gamma strong age disentangling power strongly depends strongly on the adopted resolution and galaxy velocity dispersion. We propose a system of indices which are completely insensitive to metallicity and stable against resolution, allowing the study of galaxies up to ~300 km/s. Observational spectra of very high S/N and relatively high dispersion, are required to gain this unprecedented age discriminating power. Once such spectra are obtained, accurate and reliable estimates for the luminosity-weighted average stellar ages of these galaxies will become possible for the first time, without assessing their metallicities. We measured this index for two globular clusters, a number of low-luminosity elliptical galaxies and a standard S0 galaxy. We find a large spread in the average stellar ages of a sample of low-luminosity ellipticals. In particular these indices yield 4 Gyr for M32, in agreement with the age provided by an extraordinary fit to the full spectrum of this galaxy that we achieve here.Comment: 22 pages, 4 figures. ApJ, in press. Models and details can be found at http://www.ioa.s.u-tokyo.ac.jp/~vazdekis

The first determination of the actinide Th abundance for a red giant of the Ursa Minor dwarf galaxy

The Thorium abundance for the red giant COS82 in the Ursa Minor dwarf spheroidal galaxy is determined based on a high resolution spectrum. This is the first detection of actinides in an extra Galactic object. A detailed abundance pattern is determined for 12 other neutron-capture elements from the atomic number 39 to 68. These elements are significantly over-abundant with respect to other metals like Fe (> 1 dex) and their abundance pattern agrees well with those of the r-process-enhanced, very metal-poor stars known in the Galactic halo, while the metallicity of this object ([Fe/H] ~ -1.5) is much higher than these field stars ([Fe/H] ~ -3.0). The results indicate that the mechanism and the astrophysical site that are responsible for neutron-capture elements in COS82 is similar to that for field r-process-enhanced stars, while the condition of low mass star formation is quite different. An estimate of the age of this object based on the Th abundance ratio is discussed.Comment: 5 pages, 2 figures, 1 table, to appear in PAS