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排序方式: 共有49条查询结果,搜索用时 54 毫秒
1.
Implementation of genetic algorithm in a PIC32MX microcontroller-based polarization control system is proposed and demonstrated. The controller measures the signal intensity that is used to estimate the genetic value. This process is controlled by the genetic algorithm rather than referring to the Look-Up-Table as implemented in existing solutions. To reach optimum performance, the code is optimized by using the best genetic parameters so that the fastest execution time can be achieved. An ability of genetic algorithm to work efficiently in polarization control system possesses many advantages including easy code construction, low memory consumption and fast control speed. Genetic algorithm is intelligent enough to be used for endless polarization stabilization and in the worst case, able to stabilize the polarization changes in 300 μs. In the best case the response time can reach 17 μs.  相似文献   
2.
In this paper, we address the problem of ego-motion estimation by fusing visual and inertial information. The hardware consists of an inertial measurement unit (IMU) and a monocular camera. The camera provides visual observations in the form of features on a horizontal plane. Exploiting the geometric constraint of features on the plane into visual and inertial data, we propose a novel closed form measurement model for this system. Our first contribution in this paper is an observability analysis of the proposed planar-based visual inertial navigation system (VINS). In particular, we prove that the system has only three unobservable states corresponding to global translations parallel to the plane, and rotation around the gravity vector. Hence, compared to general VINS, an advantage of using features on the horizontal plane is that the vertical translation along the normal of the plane becomes observable. As the second contribution, we present a state-space formulation for the pose estimation in the analyzed system and solve it via a modified unscented Kalman filter (UKF). Finally, the findings of the theoretical analysis and 6-DoF motion estimation are validated by simulations as well as using experimental data.  相似文献   
3.
Almost all tumors are composed of a heterogeneous cell population, making them difficult to treat. A small cancer stem cell population with a low proliferation rate and a high tumorigenic potential is thought to be responsible for cancer development, metastasis and resistance to therapy. Stem cells were reported to be involved in both normal development and carcinogenesis, some molecular mechanisms being common in both processes. No less controversial, stem cells are considered to be important in treatment of malignant diseases both as targets and drug carriers. The efforts to understand the role of different signalling in cancer stem cells requires in depth knowledge about the mechanisms that control their self-renewal, differentiation and malignant potential. The aim of this paper is to discuss insights into cancer stem cells historical background and to provide a brief review of the new therapeutic strategies for targeting cancer stem cells.  相似文献   
4.
This paper deals with application of fuzzy intelligent systems in diagnosing severity level and recommending appropriate therapies for patients having Benign Prostatic Hyperplasia. Such an intelligent system can have remarkable impacts on correct diagnosis of the disease and reducing risk of mortality. This system captures various factors from the patients using two modules. The first module determines severity level of the Benign Prostatic Hyperplasia and the second module, which is a decision making unit, obtains output of the first module accompanied by some external knowledge and makes an appropriate treatment decision based on its ontology model and a fuzzy type-1 system. In order to validate efficiency and accuracy of the developed system, a case study is conducted by 44 participants. Then the results are compared with the recommendations of a panel of experts on the experimental data. Then precision and accuracy of the results were investigated based on a statistical analysis.  相似文献   
5.
In this research, the effect of carbon dioxide laser irradiation on various properties of raw and bleached cotton fabrics, including fabric weight, bending rigidity, wetting, and air permeability, as well as dyeing, was examined and compared. The experiments were carried out at three different laser powers ranging from 4.5 to 6 W to determine the effect of laser treatment on fabric properties. In particular, the influence of laser irradiation on the dyeing properties of treated fabrics with CI Reactive Blue 198 was studied. The colour change of laser‐treated fabrics was determined by calculation of the K/S values as a function of fabric reflectance. The morphological changes in laser‐treated fabrics were observed by scanning electron microscopy. The effects of laser treatment on the properties of raw and bleached cotton fabrics were varied. For instance, the wettability of raw cotton samples was reduced after laser irradiation, whereas the wettability of bleached cotton fabrics was greater. Possible reasons for the various dyeing behaviours observed with irradiation at different laser powers are discussed.  相似文献   
6.
Owing to efficient singlet oxygen (1O2) generation in aggregate state, photosensitizers (PSs) with aggregation‐induced emission (AIE) have attracted much research interests in photodynamic therapy (PDT). In addition to high 1O2 generation efficiency, strong molar absorption in long‐wavelength range and near‐infrared (NIR) emission are also highly desirable, but difficult to achieve for AIE PSs since the twisted structures in AIE moieties usually lead to absorption and emission in short‐wavelength range. In this contribution, through acceptor engineering, a new AIE PS of TBT is designed to show aggregation‐induced NIR emission centered at 810 nm, broad absorption in the range between 300 and 700 nm with a large molar absorption coefficient and a high 1O2 generation efficiency under white light irradiation. Further, donor engineering by attaching two branched flexible chains to TBT yielded TBTC8 , which circumvented the strong intermolecular interactions of TBT in nanoparticles (NPs), yielding TBTC8 NPs with optimized overall performance in 1O2 generation, absorption, and emission. Subsequent PDT results in both in vitro and in vivo studies indicate that TBTC8 NPs are promising candidates in practical application.  相似文献   
7.
The reduced electrical screening in 2D materials provides an ideal platform for realization of exotic quasiparticles, that are robust and whose functionalities can be exploited for future electronic, optoelectronic, and valleytronic applications. Recent examples include an interlayer exciton, where an electron from one layer binds with a hole from another, and a Holstein polaron, formed by an electron dressed by a sea of phonons. Here, a new quasiparticle is reported, “polaronic trion” in a heterostructure of MoS2/SrTiO3 (STO). This emerges as the Fröhlich bound state of the trion in the atomically thin monolayer of MoS2 and the very unique low energy soft phonon mode (≤7 meV, which is temperature and field tunable) in the quantum paraelectric substrate STO, arising below its structural antiferrodistortive (AFD) phase transition temperature. This dressing of the trion with soft phonons manifests in an anomalous temperature dependence of photoluminescence emission leading to a huge enhancement of the trion binding energy (≈70 meV). The soft phonons in STO are sensitive to electric field, which enables field control of the interfacial trion–phonon coupling and resultant polaronic trion binding energy. Polaronic trions could provide a platform to realize quasiparticle‐based tunable optoelectronic applications driven by many body effects.  相似文献   
8.
A new strategy for the synthesis of thiolated carboxymethyl chitosan-g-cyclodextrin nanoparticles by an ionic-gelation method is presented. The synthetic approach was based on the utilization of 1,6-hexamethylene diisocyanate during cyclodextrin grafting onto carboxymethyl chitosan. The use of the 1,6-hexamethylene diisocyanate resulted in reactions between cyclodextrin and active sites at the C6-position of chitosan, and preserved amino groups of chitosan for subsequent reactions with thioglycolic acid, as the thiolating agent, and tripolyphosphate, as the gelling counterion. Various methods such as scanning electron microscopy, rheology and in vitro release studies were employed to exhibit significant features of the nanoparticles for mucosal albendazole delivery applications. It was found that the thiolated carboxymethyl chitosan-g-cyclodextrin nanoparticles prepared using an aqueous solution containing 1 wt% of tripolyphosphate and having 115.65 (μmol/g polymer) of grafted thiol groups show both the highest mucoadhesive properties and the highest albendazole entrapment efficiency. The latter was confirmed theoretically by calculating the enthalpy of mixing of albendazole in the above thiolated chitosan polymer.  相似文献   
9.
ZnS and CdS nanoparticles were prepared by a simple microwave irradiation method under mild conditions. The obtained nanoparticles were characterized by XRD, TEM and EDX. The results indicated that high purity of nanosized ZnS and CdS was successfully obtained with cubic and hexagonal crystalline structures, respectively. The band gap energies of ZnS and CdS nanoparticles were estimated using UV-visible absorption spectra to be about 4.22 and 2.64 eV, respectively. Photocatalytic degradation of methylene blue was carried out using physical mixtures of ZnS and CdS nanoparticles under a 500-W halogen lamp of visible light irradiation. The residual concentration of methylene blue solution was monitored using UV-visible absorption spectrometry. From the study of the variation in composition of ZnS:CdS, a composition of 1:4 (by weight) was found to be very efficient for degradation of methylene blue. In this case the degradation efficiency of the photocatalyst nanoparticles after 6 h irradiation time was about 73% with a reaction rate of 3.61 × 10−3 min−1. Higher degradation efficiency and reaction rate were achieved by increasing the amount of photocatalyst and initial pH of the solution.  相似文献   
10.
Siahmazgi cheese is an Iranian locally-made cheese produced from ewe's milk or a mixture of ewe and goat's milks in the suburbs of Rasht in the north of Iran. This kind of cheese is kept in sheepskin for six months under special condition which cause distinct physicochemical and textural characteristics. Therefore, in the present study the effect of ripening time (6 months) on the chemical, physicochemical, rheological and textural characteristics of Siahmazgi cheese (18 samples) was investigated. The rheological and textural properties were determined using rheometer (frequency sweep) and texture analyzer (uniaxial compression). Based on our findings, the measured values including pH, titratable acidity (TA), dry matter, fat, protein, ash, salt content, water soluble nitrogen in total nitrogen, and non-protein-nitrogen in total nitrogen significantly increased during ripening (P < 0.05). Furthermore, the results showed that the six-month ripened Siahmazgi cheese contained high values of dry matter (59.95 ± 0.08 g/100 g), salt (5.65 ± 0.05 g/100 g), and ash (7.24 ± 0.02 g/100 g). Regarding rheological and textural properties, storage modulus (G′), loss modulus (G″), fracture stress (σf) and firmness increased while loss tangent and fracture strain decreased.  相似文献   
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