The time, the path, its length and strenuousness in maze learning

Previous findings show that rats in a maze tend to choose the shortest path to reach food. But it is not clear whether this choice is based on path length solely, or some other factors. The aim of this experiment was to investigate which factor dominates the behavior in a maze: path (longer and shorter), time (longer and shorter), or effort (more or less strenuous). The experiment involved 40 mice (4 groups), learning a maze with two paths. Each group went through only one of the situations within which we kept one factor constant on two paths while the remaining two factors were varied. Only in the fourth situation all factors were equalized. The results show that there is a statistically significant difference in the maze path preference between four situations. Preference between the paths is such that mice always choose paths requiring less effort.

Nonlinear Doubly Wiener Constant-Stress Accelerated Degradation Model Based on Uncertainties and Acceleration Factor Constant Principle

Although Wiener process models with the consideration of uncertainties, which are nonlinearity, random effects, and measurement errors, have been developed for lifetime prediction in the accelerated degradation test (ADT), they fail to describe the real degradation process because these models assume that the drift parameter correlates with the applied stress, while the diffusion parameter is constant. This paper put forward a nonlinear doubly Wiener constant-stress accelerated degradation model, where both diffusion and drift parameters were compatible with the applied stress according to the acceleration factor constant principle. When degradation data were available, we obtained the unknown parameters by applying a maximum likelihood estimation (MLE) algorithm in the constant-stress ADT (CSADT) model taking uncertainties into account. In addition, the proposed model’s effectiveness was validated through an illustrative example, and an application to the traveling wave tube (TWT) was carried out to demonstrate the superiority of our model in practical applications.

A RESOURCE USE EFFICIENCY OF ORTHODOX TEA IN ILLAM DISTRICT OF NEPAL

Despite of the high rate of the orthodox tea, the net margin is still below the satisfactory level. Thus, the present research was conducted to estimate the cost and production efficiency of orthodox tea in Ilam district of Nepal. A total of 160 samples were collected, 80 each from organic and conventional tea growing area of Deumai rural municipality, Ilam municipality and two wards of Suryodaya municipality. Similarly, 4 tea processing factories and 5 local traders were selected purposely. The B:C ratio of conventional orthodox tea farming (2.76) was significantly higher organic orthodox tea production (2.07). With 1 percent increase in fertilizer and manure cost would significantly decrease (p<0.05) the revenue from orthodox tea by 0.07 percent keeping another factor constant. Similarly, organic orthodox tea over conventional orthodox tea farming, the revenue will significantly decrease (p<0.01) by 47 percent other factors remaining constant the result indicate that with respect to fertilizer and labor it was found that increase in fertilizer and manure cost would decrease the revenue from orthodox tea.

Control Strategies of Power and Power Factor using PID Controller in Hybrid Energy System

Now a days maximum rise of power can be done by the usage of wind ,solar and diesel system. To get reliable electricity supply and to control the interruption and contingency hybrid power systems are used. The hybrid systems are more advantageous because both the wind and solar are renewable energies which is more convenient to the environment. The work presented in this paper consists of a combination of a wind system ,a PV system and an AC load with a back up of battery source and a diesel generator. Inorder to reduce the transmission cost this system is applicable and it can be used in remote areas. PID controller with PLL technique is used to maintain the power factor constant even when one of the source is in OFF condition. The ON/OFF condition is given manually on the input side and accordingly the energy sources will produce the voltage/current output thereby power factor is maintained constant with the irradiance and temperature. One of the advantage of this system avoids penalty by maintaining the power factor constant.

Design of an Optimal Plan of Accelerated Degradation Test via Acceleration Factor Constant Principle

Accelerated degradation test (ADT) has been extensively applied to reliability assessment. To improve the efficiency–cost ratio of ADT, the optimal design method of ADT has become a research hot topic. An optimal design method based on acceleration factor, in which a Wiener degradation model and a step-stress ADT were considered, was proposed in the paper. In order to establish an accurate accelerated degradation model, acceleration factor constant principle was applied to derive the changing rules of Wiener process parameters with accelerated stress. Besides, the exact expression of acceleration factor was determined for a Wiener degradation model. The asymptotic variance of acceleration factor, which was considered as a measure of the consistency of failure mechanisms, was selected to be the objective function of optimal problem so as to ensure that the failure mechanism of products under accelerated stresses is probably consistent with that under the normal use stresses. A numerical example of designing an optimal ADT plan for a certain type electrical connector was studied, in which the effectiveness and feasibility of the proposed method were validated.

Design of Far-Red Sensitizing Squaraine Dyes Aiming Towards the Fine Tuning of Dye Molecular Structure

Model squaraine dyes having sharp and narrow absorptions mainly in the far-red wavelength region has been logically designed, synthesized and used for their application as sensitizer in the dyesensitized solar cells (DSSC). In order to have fine control on energetics, dyes having same mother core and alkyl chain length varying only in molecular symmetry and position of substituent were designed. It has been found that even keeping all other structural factor constant, only positional variation of substituent leads to not only in the variation of energetics by 0.1 eV but affects the photovoltaic characteristics also. Optimum concentration of dye de-aggregating agent was found to be 100 times with respect to the sensitizing dye concentration. Amongst dyes utilized in this work best performance was obtained for unsymmetrical dye SQ-40 giving a photoconversion efficiency of 4.01% under simulated solar irradiation at global AM 1.5.