Changes of adrenocorticotropic hormone rhythm and cortisol circadian rhythm in patients with depression complicated with anxiety and their effects on the psychological state of patients

Objective: This work was to explore the rhythm of adrenocorticotropic hormone (ACTH) and cortisol in patients with depression and anxiety and their effects on mental state. In this work, with depression complicated with anxiety patients as the A-MDD group (n = 21), and depression without anxiety symptoms as the NA-MDD group (n = 21). Firstly, data features were extracted according to the electroencephalo-graph (EEG) data of different patients, and a DR model was constructed for diagnosis. The Hamilton Depression Scale 24 (HAMD-24) was employed to evaluate the severity, and the ACTH and cortisol levels were detected and compared for patients in the A-MDD group and NA-MDD group. In addition, the psychological status of the patients was assessed using the Toronto Alexithymia Scale (TAS). As a result, the AI-based DR model showed a high recognition accuracy for depression. The HAMD-24 score in the A-MDD group (31.81 ± 5.39 points) was statistically higher than the score in the NA-MDD group (25.25 ± 5.02 points) (P < 0.05). No visible difference was found in ACTH levels of patients in different groups (P > 0.05). The incidence of cortisol rhythm disorder (CRD) in the A-MDD group was much higher (P < 0.05). The differences in TAS scores between the two groups were significantly statistically significant (P < 0.01). In conclusion, the AI-based DR Model achieves a more accurate identification of depression; depression with or without anxiety has different effects on the mental state of patients. CRD may be one of the biological markers of depression combined with anxiety

Muscle activity-driven green-oriented random number generation mechanism to secure WBSN wearable device communications

Wireless body sensor networks (WBSNs) mostly consist of low-cost sensor nodes and implanted devices which generally have extremely limited capability of computations and energy capabilities. Hence, traditional security protocols and privacy enhancing technologies are not applicable to the WBSNs since their computations and cryptographic primitives are normally exceedingly complicated. Nowadays, mobile wearable and wireless muscle-computer interfaces have been integrated with the WBSN sensors for various applications such as rehabilitation, sports, entertainment, and healthcare. In this paper, we propose MGRNG, a novel muscle activity-driven green-oriented random number generation mechanism which uses the human muscle activity as green energy resource to generate random numbers (RNs). The RNs can be used to enhance the privacy of wearable device communications and secure WBSNs for rehabilitation purposes. The method was tested on 10 healthy subjects as well as 5 amputee subjects with 105 segments of simultaneously recorded surface electromyography signals from their forearm muscles. The proposed MGRNG requires only one second to generate a 128-bit RN, which is much more efficient when compared to the electrocardiography-based RN generation algorithms. Experimental results show that the RNs generated from human muscle activity signals can pass the entropy test and the NIST random test and thus can be used to secure the WBSN nodes

Mechanical properties and failure law of composite rock containing two coplanar fractures

Composite rocks comprise the rock structures that are commonly used in geotechnical engineering. The fracture configuration has a substantial influence on the mechanical behavior, failure mode, and crack propagation of composite rocks. In this study, we considered a composite rock with two prefabricated coplanar fractures. Through laboratory uniaxial compression tests and using a digital image acquisition system, we systematically studied the effects of different fracture lengths and inclination angles on the mechanical properties and failure characteristics of the rocks. We obtained the following results: 1) during the loading deformation of the rock sample, the peak stress and elastic modulus increased with an increase in the fracture inclination angle and decreased with an increase in the fracture length. The deterioration coefficient k (the ratio of the difference between the peak strength of intact and fractured rock sample to that of intact rock sample) decreased with an increase in the fracture inclination angle and increased with an increase in the fracture length. 2) The failure type of the rock samples was primarily controlled by the fracture inclination angle and material of the two rock types, and the fragmentation degree was primarily controlled by the fracture length. With an increase in the fracture inclination angle, the failure mode of rock sample exhibited the following order of changes leading to failure: a double-Y type (trwo wing and one antiwing cracks appeared on each prefabricated fracture) → double-Z type (two wing cracks appeared on each prefabricated fracture) → Z type (one wing crack appeared on each prefabricated fracture). 3) The type of coalescence of the rock bridge was controlled by the fracture inclination angle and structural plane. The crack positions were primarily affected by the fracture length. 4) At a low fracture inclination angle (α ≤ 30°), the propagation of the microcracks showed aggregated band formation. Above moderate fracture inclination angles (α > 30°), the microcrack aggregation band gradually weakened and expanded in the direction of dispersion

Development of a Novel Disturbance Observer Based Fractional Order PD Controller for a Gun Control System

Motion control of gun barrels is an ongoing topic for the development of gun control equipment (GCE) with excellent performances. In this paper, a novel disturbance observer (DOB) based fractional order PD (FOPD) control strategy is proposed for the GCE. By adopting the DOB, the control system behaves as if it were the nominal closed-loop system in the absence of disturbances and uncertainties. The optimal control parameters of the FOPD are determined from the loop-shaping perspective, and the Q-filter of the DOB is deliberately designed with consideration of system robustness. The linear frame of the proposed control system will enable the analysis process more convenient. The disturbance rejection properties and the tracking performances of the control system are investigated by both numerical and experimental tests, the results demonstrate that the proposed DOB based FOPD control system is of more robustness, and it is much more suitable for the gun control system with strong nonlinearity and disturbance

Year-round performance assessment of a ground source heat pump with multiple energy piles

The year-round performance of a ground source heat pump (GSHP) with multiple energy piles (EPs) is investigated in this study based on a 3D transient heat transfer model. The GSHP heating and cooling capabilities are simulated and assessed according to thermal energy demands of an air conditioned domestic building, its coefficients of performance (COPs) obtained from numerical analyses and experimental tests are compared and the largest difference between them is less than 8%. The maximum heating and cooling COPs of the GSHP are 3.63 and 4.73 respectively in the first year operation period, and the soil final temperature is lower than its initial temperature, therefore the soil is not capable of recovering by itself due to the building unbalanced heating and cooling loads. Finally, the effects of the soil thermal properties on its temperature and the GSHP COPs are investigated and compared between the first year and tenth year operations, and it is found that the soil with low volumetric heat capacity and high thermal conductivity could achieve a quick temperature recovery

Simulation analysis on performance of fast variable load for marine steam power system

[Objectives] The fast variable load capacity of steam power system is a key technical index to determine the maneuverability of ships, which is of great significance to the safety and stability of marine navigation.[Methods] Simulation model of steam power system including of supercharged boiler,steam turbine unit,feedwater pumps and other equipments is established. Based on the experimental data,the stability and accuracy of the simulation model is verified. The dynamic performance of steam power system is simulated under fast rising and reducing load conditions.[Results] The calculation results show that a slow matching rate between turbocharger unit and boiler,which restricts the fast rising load capacity of the steam power system. Meanwhile,steam back brake of steam turbine unit is lack of ability,which restricts the fast reducing load capacity of the steam power system.[Conclusions] The research results can provide theoretical support for the design and optimization of the steam power system of a real ship

Response characteristics of ship steam power system under switchover of turbine feed water pump

[Objectives] The switching performance of turbine feed water pump is a key technical indicator to decide the operation stability of ship steam power system, and it is of great significance to the safety of navigation.[Methods] Using the Modular Modeling System(MMS) thermal engineering system simulation software, a simulation model of ship steam turbine power system based on the switching principle of turbine feed water pump is established. Meanwhile, the accuracy of the simulation model is verified by experiment data. The dynamic response of turbine feed water pump to steam-water cycle of steam turbine power system is analyzed under high-speed and low-speed conditions.[Results] The calculation results show that switchover of turbine feed water pump can meet the water supply demand of supercharged boiler under high-speed and low-speed conditions. After switching, the system can run stably under low-speed condition, but the operation of the system is unstable after switching under high-speed condition. It shows that the water level of the condenser rapidly rises to an extremely high level, and the water level of the deaerator drops sharply to an extremely low level. Severe pressure fluctuation occurs in exhaust steam and micro superheated steam.[Conclusions] The research results can provide theoretical support for the optimization of the switching scheme of the steam turbine feed water pump