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As decarbonisation of the power sector is essential to achieve Japan’s target of net-zero greenhouse gas (GHG) emissions by 2050, it becomes crucial to address how the electricity system incorporates short- and long-term variability in the power output via renewable energy. In this paper, we developed six scenarios for 100% renewable energy in Japan’s power sector and conducted electricity system simulations of least-cost security-constrained unit commitment (SCUC) and security-constrained economic dispatch (SCED) of generators with capacity constraints for high-voltage transmission lines. The electricity demand under all scenarios assumed a drastic increase in electrification in all sectors and the use of hydrogen in areas where electrification is difficult. Regarding the electricity system, we assumed the use of the existing capacity of transmission lines with minor reinforcement in response to electrification and cross-regional coordination but not to renewable energy expansion. The results indicated that the domestic renewable energy share in the power mix can be increased to 100% within the constraints of the top two high-voltage transmission lines while maintaining the curtailment rate of renewable energy below 5% if hydrogen is produced using surplus renewable energy for power-to-gas (P2G) technology. It will become important to secure long-term flexibility for energy storage in large quantities across seasons, such as hydrogen-fired power plants with underground hydrogen storage. It was also shown that Japan exhibits enough potential to store hydrogen, which can be used for hydrogen-fired power plants and energy-intensive industries.

Purpose: The purpose of this paper is to discuss whether top management will assume their liabilities especially when financial restatement occurs, and,based on the “effective supervision theory” and “strategic cooperation theory,” to examine whether an institutional investor is a supervisor or a cooperator considering the management turnover caused by financial restatement in the companies. Design/methodology/approach: Using a sample of the A-share-listed companies from year 2010 to year 2014 and dividing financial restatement into fraudulent financial restatement and other financial restatement, the authors examine the relationship between financial restatement and abnormal management turnover, which usually is related to the management integrity or capacity. By using group test methods, the authors test the influence of the institutional investors’ shareholding on the relation between financial restatements and management turnover. Findings: This paper finds that financial restatement can result in abnormal management turnover, especially the fraudulent financial restatement. The institutional investors usually are supervisors but when the shareholding of institutional investor is too high and the management turnover results from fraudulent financial restatement, the institutional investors may become cooperators with management in the companies. Besides, the institutional investors play the supervisory function more significantly in non-state-owned enterprises. Originality/value: This paper expands literature of the institutional investors in the corporate governance area and provides a basis for future research in the area of the institutional investors’ governance effect. It divides financial restatements into fraudulent financial restatement and other financial restatement and examines the relationship between financial restatement and abnormal management turnover so as to provide evidence about whether the management will assume their responsibilities when there is financial restatement in the company. It also tests whether the institutional investors will play supervisor’s or cooperator’s function in state-owned and non-state-owned enterprises.

Corporate environmental management in China has been expanding from the efforts of individual companies to various cooperative practices improving environmental performance of the supply chain, which may be classified as green supply chain management (GSCM). Using the data collected from 165 companies in the Yangtze River delta of China, this paper analyses the driving mechanisms of GSCM of the companies with different practice levels. The valid respondents are classified as laggard companies and advanced practitioners by a cluster analysis of the scores presented to the pre-defined 12 GSCM activities. Multivariate regression analyses indicate different driving models for these two groups of companies. GSCM of laggard companies are driven by the regulatory pressures and the client’s demands but restricted by the company’s capacities. The GSCM levels of advanced companies may be attributed to the company’s business strategies for development. The business competitor’s performance and top management support are identified as influential factors. This paper also confirms that GSCM practices help the improvement of environmental performances of the companies especially in terms of the reduction of pollutant emissions and the increase of employee’s environmental awareness.

This paper discusses environmental complaints made by citizens living close to industrial polluters in China. Data collected from a questionnaire survey in Suzhou City is used for the analysis. The results confirm a marginal level of citizen environmental complaints in the study area at present. Meaningful findings include the fact that citizens have a tendency to complain collectively, and that perception of the level of environmental information provided by companies significantly determines a citizen's likelihood of lodging environmental complaints. Therefore, the disclosure of corporate environmental information must be emphasized continuously; citizens must be encouraged to correctly understand the environmental performance of companies so that they might make appropriate complaints. Governments need to show their support for citizen-led environmental complaint initiatives. The successful cases would convince them to keep a closer eye on their neighbouring polluters.

The scattering of internal gravity waves at finite topography is studied theoretically and numerically for a two-dimensional finite-depth ocean. In Part I a single incident plane wave was considered. Here a random superposition of incident waves is considered with a spectrum derived from the Garrett and Munk spectrum. The topography is either a slope–shelf or ridge configuration with the bottom being flat in the far fields. The incident energy flux is partitioned into reflected and transmitted waves and redistributed in modenumber space. The scattering is irreversible. In frequency space topography acts like a filter. Waves with frequencies lower than the critical frequency are reflected. Waves with frequencies higher than the critical frequency are transmitted onto the shelf or across the ridge. In modenumber space, both the reflected and transmitted flux spectra are flatter than the incident spectrum, indicating a transfer from low to high modenumbers. This transfer is accompanied by an increase in the energy spectrum and, even more so, in the shear spectrum. A critical modenumber is determined such that the cumulative inverse Richardson number up to this modenumber is one. The flux scattered to modenumbers beyond this critical modenumber is calculated and is assumed to be available for internal wave induced boundary mixing. Various topographic profiles are compared. Convex profiles are more efficient than linear or concave profiles in scattering waves to high modenumbers.

The scattering of internal gravity waves at finite topography in two dimensions is studied theoretically and numerically for a finite depth ocean. A formal solution is derived using a mapping function based on ray tracing. The solution satisfies radiation conditions. Energy is conserved. The incoming energy flux is redistributed in physical and modenumber space. Numerical solutions are calculated for a single plane wave propagating from the ocean side onto slope–shelf configurations where a flat shallow shelf is connected to a flat deep ocean by linear slopes, staircases, convex or concave parabolic profiles, and half-cosine slopes. The fraction of the incoming energy flux transmitted onto the shelf and reflected back to the deep ocean and the distribution of these fluxes in modenumber space are calculated. The results depend on the parameters of the incident wave and of the topography. Especially important is the distinction between supercritical topography, where the slope of the topography exceeds the wave slope, and subcritical topography. Results obtained are (i) for subcritical topography nearly all of the incoming energy flux is transmitted onto the shelf; (ii) for supercritical topography part is transmitted onto the shelf and part is reflected back to the deep ocean; the partition depends on the incident modenumber and the shelf to ocean depth ratio; (iii) for a linear slope the distribution of the transmitted and reflected fluxes in modenumber space shows peaks at modenumbers roughly consistent with reflection laws; (iv) more of the incident wave energy flux is scattered to higher than to lower modenumbers, especially for near-critical topography; (v) convex slopes are more efficient in scattering the energy flux to high modenumbers than concave slopes; (vi) major differences occur when a linear slope is represented by a series of steps, especially for subscritical topography and high incident modenumbers; and (vii) the scattering results differ in important aspects from the results obtained by reflection theory, especially for supercritical topography and low incident modenumbers. Scattering at ridge configurations is also considered. The results can be inferred from the results for the slope–shelf configurations. The extension to a superposition of incident waves with a realistic spectrum and the implications for internal wave-induced boundary mixing are treated in Part II.