Network Dynamics in the 12 Regional Clusters (Japanese)

It has been observed that the origination of innovation tends to concentrate in areas in which environmental conditions are formed as clusters. It is networks with "small-world" architecture that underpin the high level of creative power for innovation that clusters possess. If it were possible, through policy efforts, to form networks of a highly small-world character that provide an environment that can facilitate a good balance between short-distance interaction and long-distance interaction, that would lead to the enhancement of a region's creative power for innovation. The cluster policy currently being implemented has completed its first phase and has reached a watershed at which it moves into the second phase. In this paper we attempt to formulate a method of objectively grasping and evaluating network architecture from the standpoint of these two types of interaction. Specifically, with regard to the architecture of major networks formed domestically, we use network analysis methods to conduct a comparative analysis of the 12 regions and fields before (in 2000) and after (in 2005) the implementation of cluster policy. As a result of this, we have clarified the following points. (1) Networks are expanding in all regions, (2) the networks that excel in long-distance interaction also excel in short-distance interaction, (3) with a small number of exceptions, the bigger the network is, the more both of these characteristics are enhanced, (4) during this five-year period there have been no major changes with regard to the comparative advantage of each region or field, (5) there is some degree of correlation between the independence of modules and the extent of their small-world character, and (6) disparities between regions are greater than disparities between industry sectors. Through the use of this analytical method it was possible to obtain a quantitative grasp of network architecture in a form that made possible comparisons with other regions and fields, and from this to extract objective information necessary for policy-making. We hope that efficient networking activity will be carried out in the future on the basis of the results of analysis of this kind.

CO Multi-line Imaging of Nearby Galaxies (COMING). III. Dynamical effect on molecular gas density and star formation in the barred spiral galaxy NGC 4303

We present the results of $^{12}$CO($J$=1-0) and $^{13}$CO($J$=1-0) simultaneous mappings toward the nearby barred spiral galaxy NGC 4303 as a part of the CO Multi-line Imaging of Nearby Galaxies (COMING) project. Barred spiral galaxies often show lower star-formation efficiency (SFE) in their bar region compared to the spiral arms. In this paper, we examine the relation between the SFEs and the volume densities of molecular gas $n(\rm{H}_2)$ in the eight different regions within the galactic disk with CO data combined with archival far-ultraviolet and 24 $\mu$m data. We confirmed that SFE in the bar region is lower by 39% than that in the spiral arms. Moreover, velocity-alignment stacking analysis was performed for the spectra in the individual regions. The integrated intensity ratios of $^{12}$CO to $^{13}$CO ($R_{12/13}$) range from 10 to 17 as the results of stacking. Fixing a kinetic temperature of molecular gas, $n(\rm{H}_2)$ was derived from $R_{12/13}$ via non-local thermodynamic equilibrium (non-LTE) analysis. The density $n(\rm{H}_2)$ in the bar is lower by 31-37% than that in the arms and there is a rather tight positive correlation between SFEs and $n(\rm{H}_2)$, with a correlation coefficient of $\sim 0.8$. Furthermore, we found a dependence of $n(\rm{H}_2)$ on the velocity dispersion of inter-molecular clouds ($\Delta V/ \sin i$). Specifically, $n(\rm{H}_2)$ increases as $\Delta V/ \sin i$ increases when $\Delta V/ \sin i < 100$ km s$^{-1}$. On the other hand, $n(\rm{H}_2)$ decreases as $\Delta V/ \sin i$ increases when $\Delta V/ \sin i > 100$ km s$^{-1}$. These relations indicate that the variations of SFE could be caused by the volume densities of molecular gas, and the volume densities could be governed by the dynamical influence such as cloud-cloud collisions, shear and enhanced inner-cloud turbulence.Comment: 15 pages, 8 figures, accepted for publication in PAS

CO Multi-line Imaging of Nearby Galaxies (COMING) IV. Overview of the Project

Observations of the molecular gas in galaxies are vital to understanding the evolution and star-forming histories of galaxies. However, galaxies with molecular gas maps of their whole discs having sufficient resolution to distinguish galactic structures are severely lacking. Millimeter wavelength studies at a high angular resolution across multiple lines and transitions are particularly needed, severely limiting our ability to infer the universal properties of molecular gas in galaxies. Hence, we conducted a legacy project with the 45 m telescope of the Nobeyama Radio Observatory, called the CO Multi-line Imaging of Nearby Galaxies (COMING), which simultaneously observed 147 galaxies with high far-infrared flux in $^{12}$CO, $^{13}$CO, and C$^{18}$O $J=1-0$ lines. The total molecular gas mass was derived using the standard CO-to-H$_2$ conversion factor and found to be positively correlated with the total stellar mass derived from the WISE $3.4 \mu$m band data. The fraction of the total molecular gas mass to the total stellar mass in galaxies does not depend on their Hubble types nor the existence of a galactic bar, although when galaxies in individual morphological types are investigated separately, the fraction seems to decrease with the total stellar mass in early-type galaxies and vice versa in late-type galaxies. No differences in the distribution of the total molecular gas mass, stellar mass, and the total molecular gas to stellar mass ratio was observed between barred and non-barred galaxies, which is likely the result of our sample selection criteria, in that we prioritized observing FIR bright (and thus molecular gas-rich) galaxies.Comment: Accepted for publication in PASJ; 47 pages, 5 tables, 29 figures. On-line supplementary images are available at this URL (https://astro3.sci.hokudai.ac.jp/~radio/coming/publications/). CO data is available at the Japanese Virtual Observatory (JVO) website (https://jvo.nao.ac.jp/portal/nobeyama/coming.do) and the project website (https://astro3.sci.hokudai.ac.jp/~radio/coming/data/

Recycling of Plastic Waste: A Systematic Review Using Bibliometric Analysis

Research into plastic recycling is rapidly increasing as ocean and land pollution and ecosystem degradation from plastic waste is becoming a serious concern. In this study, we conducted a systematic review on emerging research topics, which were selected from 35,519 studies on plastic recycling by bibliometrics analysis. Our results show that research on the biodegradability of plastics, bioplastics, life cycle assessment, recycling of electrical and electronic equipment waste, and the use of recycled plastics in construction has increased rapidly in recent years, particularly since 2016. Especially, biodegradability is the most emerging topic with the average year of publication being 2018. Our key finding is that many research area is led by developed countries, while the use of recycled plastics in the construction sector is being actively explored in developing countries. Based on our results, we discuss two types of recycling systems: responsible recycling in the country where plastic waste is generated and promoting recycling through the international division of labor between developed and developing countries. We discuss the advantages and disadvantages of both approaches and propose necessary measures for sustainable and responsible production and consumption of plastics such as waste traceability system and technology transfer between developed and developing countries

Toward a Theory of Industrial Supply Networks: A Multi-Level Perspective via Network Analysis

In most supply chains (SCs), transaction relationships between suppliers and customers are commonly considered to be an extrapolation from a linear perspective. However, this traditional linear concept of an SC is egotistic and oversimplified and does not sufficiently reflect the complex and cyclical structure of supplier-customer relationships in current economic and industrial situations. The interactional relationships and topological characteristics between suppliers and customers should be analyzed using supply networks (SNs) rather than traditional linear SCs. Therefore, this paper reconceptualizes SCs as SNs in complex adaptive systems (CAS), and presents three main contributions. First, we propose an integrated framework of CAS network by synthesizing multi-level network analysis from the network-, community- and vertex-perspective. The CAS perspective enables us to understand the advances of SN properties. Second, in order to emphasize the CAS properties of SNs, we conducted a real-world SN based on the Japanese industry and describe an advanced investigation of SN theory. The CAS properties help in enriching the SN theory, which can benefit SN management, community economics and industrial resilience. Third, we propose a quantitative metric of entropy to measure the complexity and robustness of SNs. The results not only support a specific understanding of the structural outcomes relevant to SNs, but also deliver efficient and effective support to the management and design of SNs

Recycling of Plastic Waste: A Systematic Review Using Bibliometric Analysis

Research into plastic recycling is rapidly increasing as ocean and land pollution and ecosystem degradation from plastic waste is becoming a serious concern. In this study, we conducted a systematic review on emerging research topics, which were selected from 35,519 studies on plastic recycling by bibliometrics analysis. Our results show that research on the biodegradability of plastics, bioplastics, life cycle assessment, recycling of electrical and electronic equipment waste, and the use of recycled plastics in construction has increased rapidly in recent years, particularly since 2016. Especially, biodegradability is the most emerging topic with the average year of publication being 2018. Our key finding is that many research area is led by developed countries, while the use of recycled plastics in the construction sector is being actively explored in developing countries. Based on our results, we discuss two types of recycling systems: responsible recycling in the country where plastic waste is generated and promoting recycling through the international division of labor between developed and developing countries. We discuss the advantages and disadvantages of both approaches and propose necessary measures for sustainable and responsible production and consumption of plastics such as waste traceability system and technology transfer between developed and developing countries

The Academic Landscapes of Manufacturing Enterprise Performance and Environmental Sustainability: A Study of Commonalities and Differences

This article reviews literature on manufacturing enterprise performance (MEP) and environmental sustainability (ES) to identify their commonalities and distinguishing factors; it is expected to help determine gaps and paths for future research. Topics are classified based on patterns in the citation networks of 7308 and 6275 MEP and ES articles, respectively. Additionally, a semantic linkage was computed to reveal overlap in vocabulary between the two topics. A total of 17 and 21 topics were found in MEP and ES, respectively, where the main shared theme was the green supply chain. However, research on biofuels is unique to ES, and privatization is unique to MEP, among others. The concept of “performance” has also been covered by MEP and ES researchers. This article provides an objective snapshot of current research trends based on quantitative data, and the findings may be used to guide future research directions at the intersection of MEP and ES

Bibliometric Analysis of Social Robotics Research: Identifying Research Trends and Knowledgebase

As robotics becomes ubiquitous, there is increasing interest in understanding how to develop robots that better respond to social needs, as well as how robotics impacts society. This is evidenced by the growing rate of publications on social robotics. In this article, we analyze the citation network of academic articles on social robotics to understand its structure, reveal research trends and expose its knowledgebase. We found eight major clusters, namely robots as social partners, human factors and ergonomics on human robot interaction, robotics for children’s development, swarm robotics, emotion detection, assessment of robotic surgery, robots for the elderly and telepresence and human robot interaction in rescue robots. In addition, despite its social focus, social science literature as a source of knowledge is barely present. Research trends point to studies on applications, rather than to specific technologies or morphologies, and in particular, towards robots as partners, for child development and assistance for the elderly