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151.
Sung Kyung Hong Sang Cheol Leev Jae Won Han Young-sun Ryuh 《International Journal of Control, Automation and Systems》2012,10(5):1000-1004
To achieve the goal of low-cost MEMS gyros for the precise self-localization of mobile robots, this paper presents a simple, yet effective method to minimize drifts on the heading angle by combining measurements from a gyro with measurements from wheel encoders (odometry). The main idea of the proposed approach is to estimate the accuracy of both sensors as a function of the actual maneuver being carried out, and then the output of both sensors are fused by the complementary filter taking into account the maneuvering conditions. The proposed method is applied to a mobile robot and the experimental data demonstrate the effectiveness of this approach. 相似文献
152.
Conventional access methods cannot be effectively used in large Scientific/Statistical Database (SSDB) applications. A file structure (called bit transposed file (BTF)) is proposed which offers several attractive features that are better suited for the special characteristics that SSDBs exhibit. This file structure is an extreme version of the (attribute) transposed file. The data are stored by vertical bit partitions. The bit patterns of attributes are assigned using one of several data encoding methods. Each of these encoding methods is appropriate for different query types. The bit partitions can also be compressed using a version of the run length encoding scheme. Efficient operators on compressed bit vectors have been developed and form the basis of a query language. Because of the simplicity of the file structure and query language, optimization problems for database design, query evaluation, and common subexpression removal can be formalized and efficient exact solution or near optimal solution can be achieved. In addition to selective power with low overheads for SSDBs, the BTF is also amenable to special parallel hardware. Results from experiments with the file structure suggest that this approach may be a reasonable alternative file structure for large SSDBs. 相似文献
153.
This paper presents a method of structuring the free space of a roving robot's environment into a set of overlapping convex regions ideally suited to path planning and navigation tasks. The structure of the free space environment is maintained as a hypergraph with each convex region represented by a hyperedge identifying the boundary walls of the region. A new methodology reveals the structure of free space and constructs the hypergraph representation through a directed search for a set of fundamental circits in an abstract graphical representation of the environment geometry. 相似文献
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157.
Min?-Ho?LeeEmail author Dong?-Joo?Yoon Dae?-Hee?Won Tae?-Sung?Bae Fumio?Watari 《Metals and Materials International》2003,9(1):35-42
In the present study, commercial pure Ti and Ti-6Al-4V alloy specimens with and without alkali and heat treatments were implanted
in the abdominal connective tissue of mice. Conventional stainless steel 316L was also implanted for comparison. After three
months, their biocompatibility was evaluated byin vitro andin vivo experiments. Surface structural changes of specimens due to the alkali treatment and soaking in Hank’s solution were analyzed
by XRD, SEM, XPS and AES. An apatite layer, which accelerates the connection with bone, was formed more easily on the alkali
treated specimens than the non-treated specimens. The number of macrophages, which is known to increase as the inflammatory
reaction proceeds, was much lower for the alkali and heat treated specimens than for the others. The average thickness of
the fibrous capsule formed around the implant was much thinner for the alkali and heat treated specimens than for the others. 相似文献
158.
159.
Cheol Park Won Sup Lee Se-Il Go Sang-Ho Jeong Jiyun Yoo Hee-Jae Cha Young-Joon Lee Heui-Soo Kim Sun-Hee Leem Hye Jung Kim Gon Sup Kim Soon-Chan Hong Yung Hyun Choi 《International journal of molecular sciences》2021,22(6)
Evidence suggests that augmented expression of a certain gene can influence the efficacy of targeted and conventional chemotherapies. Here, we tested whether the high expression of enhancer of the rudimentary homolog (ERH), which serves as a prognostic factor in some cancers, can influence the efficacy of anthocyanins isolated from fruits of Vitis coignetiae Pulliat, Meoru in Korea (AIMs) on human gastric cancer cells. The anticancer efficacy of AIMs was augmented in ERH-transfected MKN28 cells (E-MKN28 cells). Molecularly, ERH augmented AIM-induced caspase-dependent apoptosis by activating caspase-3 and -9. The ERH-augmented apoptotic effect was related to mitochondrial depolarization and inhibition of antiapoptotic proteins, XIAP, and Bcl-2. In addition, reactive oxygen species (ROS) generation was augmented in AIMs-treated E-MKN28 cells compared to AIMs-treated naïve MKN28 cells. In conclusion, ERH augmented AIM-induced caspase-dependent mitochondrial-related apoptosis in MKN28 cells. A decrease in expression of Bcl-2 and subsequent excessive ROS generation would be the mechanism for ERH-augmented mitochondrial-related apoptosis in AIMs-treated MKN28 cells. A decrease in expression of XIAP would be another mechanism for ERH-augmented caspase-dependent apoptosis in AIMs-treated MKN28 cells. 相似文献
160.
Nipin Sp Dong Young Kang Jin-Moo Lee Se Won Bae Kyoung-Jin Jang 《International journal of molecular sciences》2021,22(9)
Hormone-specific anticancer drugs for breast cancer treatment can cause serious side effects. Thus, treatment with natural compounds has been considered a better approach as this minimizes side effects and has multiple targets. 6-Gingerol is an active polyphenol in ginger with various modalities, including anticancer activity, although its mechanism of action remains unknown. Increases in the level of reactive oxygen species (ROS) can lead to DNA damage and the induction of DNA damage response (DDR) mechanism, leading to cell cycle arrest apoptosis and tumorsphere suppression. Epidermal growth factor receptor (EGFR) promotes tumor growth by stimulating signaling of downstream targets that in turn activates tumor protein 53 (p53) to promote apoptosis. Here we assessed the effect of 6-gingerol treatment on MDA-MB-231 and MCF-7 breast cancer cell lines. 6-Gingerol induced cellular and mitochondrial ROS that elevated DDR through ataxia-telangiectasia mutated and p53 activation. 6-Gingerol also induced G0/G1 cell cycle arrest and mitochondrial apoptosis by mediating the BAX/BCL-2 ratio and release of cytochrome c. It also exhibited a suppression ability of tumorsphere formation in breast cancer cells. EGFR/Src/STAT3 signaling was also determined to be responsible for p53 activation and that 6-gingerol induced p53-dependent intrinsic apoptosis in breast cancer cells. Therefore, 6-gingerol may be used as a candidate drug against hormone-dependent breast cancer cells. 相似文献