Computational Complexity of Smooth Differential Equations

The computational complexity of the solutions $h$ to the ordinary differential equation $h(0)=0$, $h'(t) = g(t, h(t))$ under various assumptions on the function $g$ has been investigated. Kawamura showed in 2010 that the solution $h$ can be PSPACE-hard even if $g$ is assumed to be Lipschitz continuous and polynomial-time computable. We place further requirements on the smoothness of $g$ and obtain the following results: the solution $h$ can still be PSPACE-hard if $g$ is assumed to be of class $C^1$; for each $k\ge2$, the solution $h$ can be hard for the counting hierarchy even if $g$ is of class $C^k$.Comment: 15 pages, 3 figure

A novel reduction strategy of standby power loss in the multi-oscillated current resonant DC-DC converter considering acoustic noise compatibility

The current resonant type DC-DC converter employs generally the pulse frequency modulation and its magnetizing inductance is set relatively low. For this reason, the magnetizing current through the converter causes a power loss under the light load condition. To solve this problem, a multi-oscillated current resonant type DC-DC converter has been proposed and then the advantage of its control method has been clarified, which can reduce power loss under light load condition and keep low switching noise. This paper deals with a novel reduction strategy of standby power consumption of the converter. As a result, the standby power consumption under no load condition is achieved below 60mW at 100V AC input and 150mW at 240V AC input, respectively. Furthermore, it is clarified that the slope of the resonant current envelope at soft start and end function in the standby mode influence the acoustic noise from the converter.2011 33rd International Telecommunications Energy Conference, INTELEC 2011; Amsterdam; 9 October 2011 through 13 October 201

Kraus representation in the presence of initial correlations

We examine the validity of the Kraus representation in the presence of initial correlations and show that it is assured only when a joint dynamics is locally unitary.Comment: REVTeX4, 12 page

Rpd3/CoRest-mediated activity-dependent transcription regulates the flexibility in memory updating in Drosophila

Consolidated memory can be preserved or updated depending on the environmental change. Although such conflicting regulation may happen during memory updating, the flexibility of memory updating may have already been determined in the initial memory consolidation process. Here, we explored the gating mechanism for activity-dependent transcription in memory consolidation, which is unexpectedly linked to the later memory updating in Drosophila. Through proteomic analysis, we discovered that the compositional change in the transcriptional repressor, which contains the histone deacetylase Rpd3 and CoRest, acts as the gating mechanism that opens and closes the time window for activity-dependent transcription. Opening the gate through the compositional change in Rpd3/CoRest is required for memory consolidation, but closing the gate through Rpd3/CoRest is significant to limit future memory updating. Our data indicate that the flexibility of memory updating is determined through the initial activity-dependent transcription, providing a mechanism involved in defining memory state