This paper reinterprets the economic input-output equation as a description of a realized situation without considering decision making. This paper uses the equation that the self-sufficiency rate is added to the Leontief type, and discusses its solvability. The equation has a unique solution if and only if each part of the relevant society satisfies the space-time openness condition. This condition means that commodities which a part of the relevant society possesses are not all inputted to its inside. Moreover, if the process of input and output is time irreversible, each part of the relevant society satisfies the space-time openness condition. Therefore, the solvability of the equation is guaranteed by time irreversibility. This proposition seems to be relevant to the grandfather paradox which is a type of time paradox.

A real square matrix whose non-diagonal elements are non-positive is called a Z-matrix. This paper shows a necessary and sufficient condition for non-singularity of two types of Z-matrices. The first is for the Z-matrix whose row sums are all non-negative. The non-singularity condition for this matrix is that at least one positive row sum exists in any principal submatrix of the matrix. The second is for the Z-matrix which satisfies where . Let be the ith row and the jth column element of , and be the jth element of . Let be a subset of which is not empty, and be the complement of if is a proper subset. The non-singularity condition for this matrix is such that or such that for . Robert Beauwens and Michael Neumann previously presented conditions similar to these conditions. In this paper, we present a different proof and show that these conditions can be also derived from theirs.

Abstract:
The essence of money circulation is that money continues to transfer among economic agents eternally. Based on this recognition, this paper shows a money circulation equation that calculates the quantities of expenditure, revenue, and the end money from the quantity of the beginning money. The beginning money consists of the possession at term beginning, production and being transferred from the outside of the relevant society. The end money consists of the possession at term end, disappearance and transferring to the outside of the relevant society. This equation has a unique solution if and only if each part of the relevant society satisfies the space-time openness condition. Moreover, if money is transferred time irreversibly, each part of the relevant society satisfies the space-time openness condition. Hence, the solvability of the equation is guaranteed by time irreversibility. These solvability conditions are similar to those of the economic input-output equation, but the details are different. An equation resembling our money circulation equation was already shown by Mária Augustinovics, a Hungarian economist. This paper examines the commonalities and differences between our equation and hers. This paper provides the basis for some intended papers by the author.

Abstract:
This paper describes the mechanical properties of the composite materials produced using long bamboo fiber and bamboo powder. Bamboo fiber and powder can be hot press-molded much like plastic materials, and the use of these materials in place of plastic products would reduce the environmental impact of extensive plastic use. In this study, the tensile and flexural properties of molded uni-directional long fiber reinforced composites made from bamboo fiber bundles and Bamboo powder were examined. The results showed that the tensile and flexural strength of bamboo fiber/powder composites were increased with increasing fiber content. On the other side, both strengths of composite were decreased with increasing molding temperature after 180℃. The highest tensile and flexural strengths of the bamboo fiber reinforced bamboo powder composites specimens which were tested were recorded at 169.9 MPa and 221.1 MPa, respectively.

Abstract:
In a monetary economy, expenditure induces revenue for each agent. We
call this the revenue induction phenomenon. Moreover, in a special case, part
of the expenditure by an agent returns as their own revenue. We call this the
expenditure reflux phenomenon. Although the existence of these phenomena is
known from the olden days, this paper aims to achieve a more precise quantification
of them. We first derive the revenue induction formula through solving the
partial money circulation equation. Then, for a special case, we derive the
expenditure reflux formula. Furthermore, this paper defines the revenue induction
coefficient and the expenditure reflux coefficient, which are the key concepts
for understanding the two formulas, and examines their range.

Abstract:
This paper describes the flexural properties of biodegradable composites made using natural fiber
and biodegradable plastics. Biodegradable composites were fabricated from bamboo fiber
bundles and PLA (polylactic acid) resin. In this research, effect of molding temperature and fiber
content on flexural properties of bamboo fiber reinforced composites was investigated. The flexural
strength of this composite increased with increasing fiber content up to 70%. The flexural
strength of composites decreased at molding temperature of 180°C. Biodegradable composites
possessed extremely high flexural strength of 273 MPa, in the case of molding temperature of
160°C and fiber content of 70%.

Abstract:
This paper aims to inquire into an objectively authentic budget constraint in a monetary economy through showing two missing problems of the monetary budget constraint and their solutions. To start with, we show the first missing problem that money is “missing” if all agents expend their total budgets under the simple budget constraint. This problem shows that the simple budget constraint is inadequate as an objective monetary budget constraint. A deficiency of the simple budget constraint exists partly in that it does not reflect money circulation. To improve this deficiency, we incorporate the expenditure reflux formula into the simple constraint. The first missing problem is partially solved by the application of this reflux budget constraint, but another problem occurs. The new problem is that infinite expenditure is permitted under this constraint. This is the second missing problem. The second problem appears to be a variation of the solvability problem of the money circulation equation. Referring to the proof of the solvability, we incorporate a time irreversible disposal into the budget constraint. This irreversibility budget constraint brings us a provisional solution of the missing problems. However, it should not be called a perfect solution. We also examine the relationships between our research and two previous studies: the finance constraint and the cash-in-advance model.

Abstract:
Natural plant fibers, including flax, kenaf, jute, bamboo, ramie and much
more are renewable and sustainable resources and are considered good candidates
for cost-effective alternatives to glass and carbon fibers. In this research,
cross ply biodegradable composites were fabricated by press-forming method. The
biodegradable composites consist of Manila hemp textile as a reinforcement and
starch-based biodegradable plastics as a matrix was fabricated and investigated
about mechanical properties. The tensile strength increased with the fiber
content until fiber content of about 50% and leveled off thereafter. This
dependence on the fiber content is due to the decrease in fiber strength of
loading direction caused by fiber damages introduced during hot-pressing. In
order to decrease the damage of fibers aligned in loading direction, Manila
hemp textile was produced by using Manila hemp fibers for warp and
biodegradable resin thread for weft. As a result, the tensile strength of cross
ply composites increased from 153 MPa to 202 MPa.

Abstract:
Testing-time when a change of a stochastic characteristic of the software failure-occurrence time or software failure-occurrence time-interval is observed is called change-point. It is said that effect of the change-point on the software reliability growth process influences on accuracy for software reliability assessment based on a software reliability growth model (SRGM). We propose an SRGM with the effect of the change-point based on a bivariate SRGM, in which the software reliability growth process is assumed to depend on the testing-time and testing-effort factors simultaneously, for accurate software reliability assessment. And we discuss an optimal software release problem for deriving optimal testing-effort expenditures based on our model. Further, we show numerical examples of software reliability assessment based on our bivariate SRGM and estimation of optimal testing-effort expenditures by using actual data.

Abstract:
We present a new technique for estimating cell surface geometry. A dish supporting adherent cells is observed using oblique transillumination and rotated in the horizontal plane using a stepping motor. The stage rotation-dependent movements of the start and end points of a shadow formed behind the illuminated cells uniquely determine the relative height differences between points along the cell surface. Thus, using custom-made apparatuses and living endothelial cells, we demonstrate that the combination of a rotating stage and oblique lighting allows for the evaluation of three-dimensional surface geometry of adherent cells. As compared to confocal microscopy and atomic force microscopy, which are commonly used for measuring cell surface geometry, this approach can be performed rapidly and is especially suitable for the observation of unstained cells over a large surface covering multiple cells at a time.