Energy harvesting over Rician fading channel: A performance analysis for half-duplex bidirectional sensor networks under hardware impairments

In this paper, a rigorous analysis of the performance of time-switching energy harvesting strategy that is applied for a half-duplex bidirectional wireless sensor network with intermediate relay over a Rician fading channel is presented to provide the exact-form expressions of the outage probability, achievable throughput and the symbol-error-rate (SER) of the system under the hardware impairment condition. Using the proposed probabilistic models for wireless channels between mobile nodes as well as for the hardware noises, we derive the outage probability of the system, and then the throughput and SER can be obtained as a result. Both exact analysis and asymptotic analysis at high signal-power-to-noise-ratio regime are provided. Monte Carlo simulation is also conducted to verify the analysis. This work confirms the effectiveness of energy harvesting applied in wireless sensor networks over a Rician fading channel, and can provide an insightful understanding about the effect of various parameters on the system performance.Web of Science186art. no. 1781

Two-way half duplex decode and forward relaying network with hardware impairment over Rician fading channel: system performance analysis

In this paper, the system performance analysis of a two-way decode and forward (DF) relaying network over the Rician fading environment under hardware impairment effect is proposed, analyzed and demonstrated. In this analysis, the analytical mathematical expressions of the achievable throughput, the outage probability, and ergodic capacity were proposed, analyzed and demonstrated. After that, the effect of various system parameters on the system performance is deeply studied with closed-form expressions for the system performance. Finally, the analytical results are also demonstrated by Monte-Carlo simulation in comparison with the closed-form expressions. The numerical results demonstrated and convinced the effect of the system parameters on the system performance of the two-way DF relaying network. The results show that the analytical mathematical and simulated results match for all possible parameter values.Web of Science242787

System Performance Analysis of Half-Duplex Relay Network over Rician Fading Channel

In this paper, the system performance of an amplify-and-forward (AF) relaying network over Rician Fading Channel is proposed, analyzed and demonstrated. For details this analysis, the energy and information are transferred from the source to the relay nodes by two methods: 1) time switching protocol and 2) power splitting protocol. Firstly, due to the constraint of the wireless energy harvesting at the relay node, the analytical mathematical expressions of the achievable throughput and the outage probability of both schemes were proposed and demonstrated. After that, the effect of various system parameters on the system performance is rigorously studied with closed-form expressions for the system performance. Finally, the analytical results are also demonstrated by Monte-Carlo simulation in comparison with the closed-form expressions. The numerical results demonstrated the effect of various system parameters, such as energy harvesting time, power splitting ratio, source transmission to noise power, and the threshold value, on the system performance of AF wireless relay nodes. The results show that the analytical mathematical and simulated results match for all possible parameter values for both schemes

Effect of the green-emitting CaF2:Ce3+,Tb3+ phosphor particles’ size on color rendering index and color quality scale of the in-cup packaging multichip white LEDs

In this paper, we investigate the effect of the green-emitting CaF2:Ce (3+), Tb (3+) phosphor particle's size on the color rendering index (CRI) and the color quality scale (CQS) of the in-cup packaging multichip white LEDs (MCW-LEDs). For this purpose, 7000K and 8500K in-cup packaging MCW-LEDs is simulated by the commercial software Light Tools. Moreover, scattering process in the phosphor layers is investigated by using Mie Theory with Mat Lab software. Finally, the research results show that the green-emitting CaF2: Ce (3+), Tb (3+) phosphor's size crucially influences on the CRI and CQS. From that point of view, CaF2: Ce (3+), Tb (3+) can be proposed as a potential practical direction for manufacturing the in-cup packaging phosphor WLEDs.Web of Science13235134

Improving Multi-task Learning via Seeking Task-based Flat Regions

Multi-Task Learning (MTL) is a widely-used and powerful learning paradigm for training deep neural networks that allows learning more than one objective by a single backbone. Compared to training tasks separately, MTL significantly reduces computational costs, improves data efficiency, and potentially enhances model performance by leveraging knowledge across tasks. Hence, it has been adopted in a variety of applications, ranging from computer vision to natural language processing and speech recognition. Among them, there is an emerging line of work in MTL that focuses on manipulating the task gradient to derive an ultimate gradient descent direction to benefit all tasks. Despite achieving impressive results on many benchmarks, directly applying these approaches without using appropriate regularization techniques might lead to suboptimal solutions on real-world problems. In particular, standard training that minimizes the empirical loss on the training data can easily suffer from overfitting to low-resource tasks or be spoiled by noisy-labeled ones, which can cause negative transfer between tasks and overall performance drop. To alleviate such problems, we propose to leverage a recently introduced training method, named Sharpness-aware Minimization, which can enhance model generalization ability on single-task learning. Accordingly, we present a novel MTL training methodology, encouraging the model to find task-based flat minima for coherently improving its generalization capability on all tasks. Finally, we conduct comprehensive experiments on a variety of applications to demonstrate the merit of our proposed approach to existing gradient-based MTL methods, as suggested by our developed theory.Comment: 29 pages, 11 figures, 6 table

A simple, effective, green method for regioselective 3-acylation of unprotected indoles

A fast and green method is developed for regioselective acylation of indoles in the 3-position without the need for protection of the NH position. The method is based on Friedel-Crafts acylation using acid anhydrides. The method has been optimized, and Y(OTf)3 in catalytic amounts is found to be the best catalyst together with the commercially available ionic liquid [BMI]BF4 (1-butyl-3-methylimidazolium tetrafluoro-borate) as solvent. The reaction is completed in a very short time using monomode microwave irradiation. The catalyst can be reused up to four times without significant loss of activity. A range of substituted indoles are investigated as substrates, and thirteen new compounds have been synthesized

Performance analysis for power-splitting energy harvesting based two-way full-duplex relaying network over nakagami-m fading channel

Energy harvesting relay network is considered as the promising solution for a wireless communication network in our time. In this research, we present and demonstrate the system performance of the energy harvesting based two-way full-duplex relaying network over Nakagami-m fading environment. Firstly, we propose the analytical expressions of the achievable throughput and outage probability of the proposed system. In the second step, the effect of various system parameters on the system performance is presented and investigated. In the final step, the analytical results are also demonstrated by Monte-Carlo simulation. The numerical results demonstrated and convinced the analytical and the simulation results are agreed with each other

Biological activities of in vitro liverwort Marchantia polymorpha L. extracts

To overcome the problems in liverwort collecting such as small size and easily mixed with other species in the wild, we have successfully cultivated Marchantia polymorpha L. under in vitro conditions in the previous study. The aim of this study is to evaluate the biological activities of this in vitro biomass as a confirmation of the sufficient protocol in cultivation this species. Cultured biomass was dried at a temperature of 45-50 oC to constant weight and ground into a fine powder. The coarse powder was extracted with organic solvents of increasing polarization including n-hexane, chloroform, ethyl acetate, and ethanol using the maceration technique. Four extracts were investigated antioxidant (iron reduction power, DPPH), antibacterial (agar diffusion), tyrosinase inhibitory activity, anti-proliferation on MCF-7 cells. Additionally, the presence of natural metabolite groups of the extracts was detected by using specific reagents. For antioxidant activity, ethyl acetate fraction extract had the highest iron reducing power and DPPH free radical scavenging ability with IC50 = 439.31 µg ml-1. All three n-hexane, chloroform, and ethyl acetate extracts possessed resistance to the bacterial strain tested. At a concentration of 2 mg ml-1, n-hexane and chloroform extracts had the highest percentage of tyrosinase inhibition (69.54 and 69.10%, respectively). The n-hexane extract is a potent extract that inhibits the proliferation of MCF-7 cells with the lowest IC50 of 38.15 µg ml-1. A preliminary chemical composition survey showed that the cultured biomass liverwort contains many bioactive compounds, particularly the compounds of range of non- and less-polarized fractions

Effect of Inclusion of Fresh or dried black soldier fly larvae in Diets on Snakehead Fish's Growth Performance and Chemical Composition (<em>Channa sp.</em>)

In snakehead fish farming, feeding represents the largest portion (accounting for 50-60%) of production cost. Thus, finding an alternative natural feed that can be replaced as full or partial inclusion in snakehead fish commercial diets is urgently needed. This study was carried out to evaluate the effect of including fresh or dried black soldier fly larvae (BSFL) in diets on the growth performance and chemical composition of snakehead fish cultured in small-scale farms. Fingerlings of snakehead (5.15 ± 0.12 g) were distributed randomly into fifteen net cages (6 m^3^) at a density of 120 fish.net cage^-1^. Including five dietary treatments named: NT1 (100% commercial feed served as a control); NT2 (100% fresh BSFL); NT3 (100% dried BSFL); NT4 (50% fresh BSFL + 50% commercial feed); and NT5 (50% dried BSFL + 50% commercial feed). Each treatment was performed in triplicate. The results showed that the inclusion of fresh BSFL in diets for the snakehead fish did not affect the survival rate (82.22 - 85.56 %), improved feed conversion ratio, increased live weight (70.9 – 103.3 g) and daily weight gain (1.09 – 1.64 g.day^-1^), and fish’s yield (1.16 – 1.73 kg.m^-2^); and did not affect the chemical composition of the fish. These findings suggest that farmers should feed snakehead fish with commercial feed plus fresh black soldier fly larvae to maintain good condition factor and enhance fish growth performance and production

Comparative study of the analgesic effects of Bungarus fasciatus snake venom from Vinh Phuc and Tien Giang Provinces of Vietnam

Purpose: To determine the analgesic activity of Bungarus fasciatus venoms and their fractions from two Vietnamese Provinces. Methods: Male Swiss Albino mice were randomly divided into three groups containing 8 to 10 mice each. Control group was injected subcutaneously with normal saline, standard group received aspirin solution (50 mg/kg) perorally, and study group received a solution of crude venom or isolated fractions in physiological saline. To determine analgesic activity, acetic acid writhing and tail immersion tests were used. The venoms were separated by liquid chromatography and the analgesic activity of the fractions was analyzed. Results: Both venoms showed analgesic effect in the acetic acid writhing test, but only the venom from Tien Giang showed analgesic effect in the tail immersion test. The bioactive fractions of Vinh Phuc and Tien Giang venoms were significantly different, with most of Vinh Phuc venom fractions being more active (p &lt; 0.05). Thus, 35 min after the injection, the number of writhings decreased from 15 - 16 in the control to 0.85 ± 0.34 for the BF-4VS (Vinh Phuc) fraction compared to 2.67 ± 1.20 (p &lt; 0.05) for the BF-4DT (Thien Giang) fraction. Two proteins with analgesic activity were isolated from Vinh Phuc venom, and one with greater activity matched the known B. fasciatus phospholipase A2. Conclusion: The analgesic activity of two samples of B. fasciatus venom from two different provinces in Vietnam reveal that their pharmacological profiles differ. The isolates can be explored as leads in the development of new analgesic agents