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1.
Sensors (Basel) ; 23(3)2023 Jan 30.
Article in English | MEDLINE | ID: mdl-36772563

ABSTRACT

In this paper, we build four-part cone models to explore the coupling effect of seven cone fiber couplers. Moreover, this is the first study of the coupling effect of four layers of biological couplers in animals and other biological lives. We simulate the four layers cone couplers by using the beam propagation method, and we assume the input beam is located at the outer fiber of the central cone. Our simulation results showed that there are two wavelength regions (short and long wavelength regions) with the strongest coupling, where the most power of input optical powers of the central cones will transfer to the six surrounding cones after transmitting through the four layers of cone couplers. However, within a wavelength region of ±75 nm near to the peak wavelengths, located in the yellow-green wavelength range, the splitting ratios at the output of the outer segment of the central cone are always greater than the sum of the splitting ratios of the six surrounding cones. These cone couplers may play an important role in color preprocessing (e.g., doing opponent color processing partially). The cone fiber coupler effect and light absorption of cones are considered separately in our models. By taking account of both the cone fiber coupling effect and absorption of outer segment of L cone, we find the multiplication of the relative optical power of cone couplers, the spectral sensitivity data of the L cone, and a normalized coefficient that matches with the photopic luminous efficiency of the human eye well. This is the attempt to use both the cone fiber coupling effect and the absorption of L cones to explain the photopic luminous efficiency. The splitting ratios of the central cones are greater than 80% at peak wavelengths located in the yellow-green wavelength range, and this can help to explain why the human eye is more sensitive to green light.

2.
Opt Express ; 30(11): 19273-19287, 2022 May 23.
Article in English | MEDLINE | ID: mdl-36221709

ABSTRACT

An improved technique of continuous shaping current-injected waveforms based on the single-mode rate equations is proposed to suppress relaxation oscillations (ROs) from direct modulation of distributed feedback laser (DFB). The signal expression of shaping current is deduced theoretically from the dependence of DFB desired output waveforms in detail, and the specific parameters derivation of the different polynomial degree is also discussed necessarily. Furthermore, a polynomial p-function with inverse operation is adopted to construct the Fourier series corresponding to injection current waveform signal. The equivalent circuit model with DFB phenomenological description is injected into shaping current signal to verity the proposed validity by evaluating the static and dynamic characteristics. The simulation results of the optimized shaping signal show the good agreement with the desired output pulse including rising and falling edge and suppress the ROs amplitude dramatically at the two jump edges.

3.
Sensors (Basel) ; 22(11)2022 Jun 03.
Article in English | MEDLINE | ID: mdl-35684896

ABSTRACT

The localization problem of nodes in wireless sensor networks is often the focus of many researches. This paper proposes an opposition-based learning and parallel strategies Artificial Gorilla Troop Optimizer (OPGTO) for reducing the localization error. Opposition-based learning can expand the exploration space of the algorithm and significantly improve the global exploration ability of the algorithm. The parallel strategy divides the population into multiple groups for exploration, which effectively increases the diversity of the population. Based on this parallel strategy, we design communication strategies between groups for different types of optimization problems. To verify the optimized effect of the proposed OPGTO algorithm, it is tested on the CEC2013 benchmark function set and compared with Particle Swarm Optimization (PSO), Sine Cosine Algorithm (SCA), Whale Optimization Algorithm (WOA) and Artificial Gorilla Troops Optimizer (GTO). Experimental studies show that OPGTO has good optimization ability, especially on complex multimodal functions and combinatorial functions. Finally, we apply OPGTO algorithm to 3D localization of wireless sensor networks in the real terrain. Experimental results proved that OPGTO can effectively reduce the localization error based on Time Difference of Arrival (TDOA).


Subject(s)
Algorithms , Wireless Technology , Communication
4.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 24(6): 1237-40, 2007 Dec.
Article in Chinese | MEDLINE | ID: mdl-18232468

ABSTRACT

Hyperplasia of germs in biologic cell can consume certain amount of oxygen and thus will lay the foundation on which to metabolize and produce some substance. Using a Biologic cell, we have designed a kind of electric equipment for measurement which can quickly detect the environment-polluted germs, and take a sample of the environment-polluted germs in fresh milk and the microzyme in the process of beer produced. Adding proper amount of bio-coenzyme and ion-incentive to the germs liquor, we use the electric equipment to detect the sample in order to investigate the process of electron generation and germ's metabolization, including the measurement of the oxidation-reduction between the pole and the coenzyme, and the electrochemistry process of every reaction matter in the liquor. The result of our study shows that the method can effectively check the germ's number in fresh milk, and when compared to the traditional method (plate cultivating germs), it has the advantages of quickness, convenience and timeliness.


Subject(s)
Bacteria/isolation & purification , Beer/microbiology , Biosensing Techniques/methods , Milk/microbiology , Animals , Cattle , Electrochemistry , Food Contamination/analysis , Sensitivity and Specificity
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