A bacteria-based microrobot (bacteriobot) was proposed and investigated as a new type of active drug delivery system because of its useful advantages, such as active tumor targeting, bacteria-mediated tumor diagnosis, and therapy. In this study, we fabricated a bacteriobot with enhanced motility by selective attachment of flagellar bacteria (Salmonella typhimurium). Through selective bovine serum albumin (BSA) pattering on hydrophobic polystyrene (PS) microbeads, many S. typhimurium could be selectively attached only on the unpatterned surface of PS microbead. For the evaluation of the chemotactic motility of the bacteriobot, we developed a microfluidic chamber which can generate a stable concentration gradient of bacterial chemotactic chemicals. Prior to the evaluation of the bacteriobot, we first evaluated the directional chemotactic motility of S. typhimurium using the proposed microfluidic chamber, which contained a bacterial chemo-attractant (L-aspartic acid) and a chemo-repellent (NiSO4 ), respectively. Compared to density of the control group in the microfluidic chamber without any chemical gradient, S. typhimurium increased by about 16% in the L-aspartic acid gradient region and decreased by about 22% in the NiSO4 gradient region. Second, we evaluated the bacteriobot's directional motility by using this microfluidic chamber. The chemotactic directional motility of the bacteriobot increased by 14% and decreased by 13% in the concentration gradients of L-aspartic acid and NiSO4 , respectively. These results confirm that the bacteriobot with selectively patterned S. typhimurium shows chemotaxis motility very similar to that of S. typhimurium. Moreover, the directional motilities of the bacteria and bacteriobot could be demonstrated quantitatively through the proposed microfluidic chamber.

In this paper, based on the block (element)-wise inverse Jacket matrix, a unified fast hybrid diagonal block-wise transform (FHDBT) algorithm is proposed. A new fast diagonal block matrix decomposition is made by the matrix product of successively lower order diagonal Jacket matrix and Hadamard matrix. Using a common lower order matrix in the form of 1 1, a fast recursive structure can be developed in the FHDBT, which is able to convert a newly developed discrete cosine transform (DCT)-II, discrete sine transform (DST)-II, discrete Fourier transform (DFT), and Haar-based wavelet transform (HWT). Since these DCT-II, DST-II, DFT, and HWT are widely used in different areas of applications, the proposed FHDBT can be applied to the heterogeneous system requiring several transforms simultaneously. Comparing with pre-existing DCT-II, DST-II, DFT, and HWT, it is shown that the proposed FHDBT exhibits less the complexity as its matrix size gets larger. The proposed algorithm is also well matched to circulant channel matrix. From the numerical experiments, it is shown that a better performance can be achieved by the use of DCT/DST-II compression scheme compared with the DCT-II only compression method. Signal Processing: Image CommunicationThis work may not be copied or reproduced in whole or in part for any commercial purpose. Permission to copy in whole or in part without payment of fee is granted for nonprofit educational and research purposes provided that all such whole or partial copies include the following: a notice that such copying is by permission of Mitsubishi Electric Research Laboratories, Inc.; an acknowledgment of the authors and individual contributions to the work; and all applicable portions of the copyright notice. Copying, reproduction, or republishing for any other purpose shall require a license with payment of fee to Mitsubishi Electric Research Laboratories, Inc. All rights reserved. , a fast recursive structure can be developed in the FHDBT, which is able to convert a newly developed discrete cosine transform (DCT)-II, discrete sine transform (DST)-II, discrete Fourier transform (DFT), and Haar-based wavelet transform (HWT). Since these DCT-II, DST-II, DFT, and HWT are widely used in different areas of applications, the proposed FHDBT can be applied to the heterogeneous system requiring several transforms simultaneously. Comparing with pre-existing DCT-II, DST-II, DFT, and HWT, it is shown that the proposed FHDBT exhibits less the complexity as its matrix size gets larger. The proposed algorithm is also well matched to circulant channel matrix. From the numerical experiments, it is shown that a better performance can be achieved by the use of DCT/ DST-II compression scheme compared with the DCT-II only compression method.

We propose a stable feedback control algorithm of the buffer state using the controlled Lagrange multiplier in combined rate-distortion characteristics for a buffer-constrained adaptive quantization. The proposed algorithm is established using feedback control theory and is described by the state equation with nonlinearity in the feedback path. The nonlinearity of the state equation comes from the average distortion-rate curve of the information source. The stability of this buffer control algorithm is shown using Lyapunov stability theory. It is shown that the stability of the algorithm depends on average distortion-rate curve and buffer size, and sufficient conditions for the algorithm to be stable are obtained from the usual average distortion-rate curve. In addition, it is observed from experimental results that the performance of the proposed algorithm and the optimal algorithm is not significantly different. Although the proposed algorithm does not provide optimal performance, the algorithm can be implemented easily with quite low computational complexity, as compared with others.

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