This paper presents power management and low power techniques of our heterogeneous quad/octa-core mobile application processor (AP). This AP has a combination of high-performance 2 GHz cores and energy-efficient 1 GHz cores. The maximum performance in the octa-core configuration is 35,600 DMIPS. The key design highlights are as follows. 1) Using a dedicated PLL and H-tree clock in the high-performance CPU achieves both 2 GHz operation and reduced dynamic power. 2) A low-leakage SRAM in a 28 nm HPM process is used and the leakage current of the peripheral circuits of the SRAM macro is optimized via multiple threshold voltages (Vt) and gate lengths (Lg), resulting in 24% leakage reduction of L1 cache. 3) The effects of process and voltage variations are accurately corrected by an on-chip process sensor and direct sensing of the voltage in the power mesh of the chip. 20% dynamic power reduction, 29% leakage power reduction and 40 mV improvement of minimum operation voltage are achieved. 4) An enhanced CPU clock control mechanism is employed, which uses an on-chip delay sensor to reduce AC voltage drop. 5) The heterogeneous CPU architecture maintains high performance even during thermal throttling.

This study categorised the fishery districts in Iwate Prefecture, which were severely damaged by the Great East Japan Earthquake, using data on agriculture and fishery. Subsequently, changes in the industrial structure of coastal rural areas before and after the earthquake were clarified through an examination of both agriculture and fisheries at the same time. Using cluster analysis, district categories were classified into three cluster types (small-scale primary industry, large-scale primary industry and fishery-dominated clusters) before the earthquake and a fourth cluster (the three aforementioned clusters plus high population density clusters) after the earthquake. The industrial structure’s most significant change was in fishery-dominated clusters before the earthquake. After the earthquake, clusters with the characteristics of a high population density and small industries emerged. The change in the degree of population decline indicates that the loss of population has not accelerated in the districts where agriculture and fishery have been rebuilt in a balanced manner, although the scale may be either small or large. This finding suggests that both agriculture and fishery are important in coastal rural areas, just as the two were before the earthquake.

This study's purpose is to clear the process of reproduction of Tsunami struck farmland and factors to form farming organization by interview survey and participant observation in Otomo district and Hirota district in Rikuzentakata city. Farmers in both districts had organized to keep the farmland before the Tsunami disaster, because it was difficult to ensure full-time farmers. These organizations have done the reproduce farmland in each district after the Tsunami disaster. The reproductions of farmland have been carried out community farming organization in the both districts. But the form of community farming organizations was different because of the farm situation and habits in the district. Otomo district is one unit area. Hirota district is divided small. And the existence organization is effective as the capacity of the consensus building.