Stability analysis and dynamic equilibrium of a Kuroshio generator system

Global resources for conventional energy are currently being exhausted, and several countries worldwide are attempting to develop renewable energy. Current generator systems are a subject of ocean power research. This paper proposes a novel design of a Kuroshio generator system (KGS) that is suitable for the maritime environment of Taiwan (i.e., an average flow velocity of the Kuroshio Current is 1.45 m/s and the flow can be accelerated on Keelung Sill with a depth of 50-250 m). The KGS combined a reliable cable design and simple anchor system at sea and was not affected by motion changes of rotation axes in yaw and roll by way of an appropriate rudder design. An intuitive simulation method applied using MapleSim software was used to create a rigid KGS model. Different modeling frameworks for varied cable design and joint positions were adjusted to meet system requirements. An intuitive simulation method applied using MapleSim software was used to create a rigid KGS model. Different modeling frameworks for varied cable design and joint positions were adjusted to meet system requirements. The stability analysis was performed to determine dynamic equilibrium and motion behavior of the KGS and the combined cable design. The optimal spring stiffness and damper coefficient of polyester fibers were set as 5×105 N/m and 3×105 N∙s/m in the simulation, respectively. Furthermore, to achieve the torque equilibrium in pitch motion of the KGS, an optimal joint position that was relative to the leading infraedge of the outer duct was set at 2.2 m along the negative surge axis according to their responses in the simulation. Finally, the force and torque generated by the hydrodynamic effect in the KGS and the estimated specifications of a direct-drive permanent magnet generator equipped with an external rotor were imported into the simulation. Consequently, the motion ranges of translation axes in surge and heave were converged within 0.5 m, and the estimated output power in the KGS exceeded 54.8 kW

Profit Maximization by Forming Federations of Geo-Distributed MEC Platforms

This paper has been presented at: Seventh International Workshop on Cloud Technologies and Energy Efficiency in Mobile Communication Networks (CLEEN 2019). How cloudy and green will mobile network and services be? 15 April 2019 - Marrakech, MoroccoIn press / En prensaMulti-access edge computing (MEC) as an emerging technology which provides cloud service in the edge of multi-radio access networks aims to reduce the service latency experienced by end devices. When individual MEC systems do not have adequate resource capacity to fulfill service requests, forming MEC federations for resource sharing could provide economic incentive to MEC operators. To this end, we need to maximize social welfare in each federation, which involves efficient federation structure generations, federation profit maximization by resource provisioning configuration, and fair profit distribution among participants. We model the problem as a coalition game with difference from prior work in the assumption of latency and locality constraints and also in the consideration of various service policies/demand preferences. Simulation results show that the proposed approach always increases profits. If local requests are served with local resource with priority, federation improves profits without sacrificing request acceptance rates.This work was partially supported by the Ministry of Science and Technology, Taiwan, under grant numbers 106-2221-E-009-004 and by the H2020 collaborative Europe/Taiwan research project 5G-CORAL (grant number 761586)

Simulations and Measurements of Electric Fields Emitted from a LTE Base Station in an Urban Area

Radiation patterns emitted from a long-term evolution (LTE) base station antenna were first simulated by the finite-difference time domain (FDTD) method. The validity of simulation results of radiation patterns was further checked by measurement data. After validating the accuracy of the FDTD method, electric fields at 123 test sites around a LTE base station in an urban area of Taipei City were simulated. Simulated electric fields were also validated by comparison with measured data obtained by a high frequency selective radiation meter with an isotropic E-field probe. Simulated and measured electric fields are in the range of 0.104–1.182 and 0.098–1.179 V/m at 1795 MHz, respectively. From obtained electric field strengths, it is ensured that the urban area is a good signal environment. The maximum power density emitted from the LTE base station is about 1.853×10-4 mW/cm2 and is thus far below the safety standard value of 1.197 mW/cm2 for human exposure to RF radiation at 1795 MHz

Antioxidant and tyrosinase inhibitor from Leucaena leucocephala

The experimental design is divided into two parts: chemical analysis and bioactive assay. One antioxidant lupeol (4) and one inhibition of tyrosinase pheophorbide a methyl ester (7) were identified in Leucaena leucocephala. Both showed effective 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity compared with vitamin C, and mushroom tyrosinase compared with kojic acid. These results suggest that these constituents of L. leucocephala act as natural antioxidants and play a potential role in prevention of pigmentation.Keywords: Leucaenana leucocephala, lupeol, pheophorbide a methyl ester, antioxidant, mushroom tyrosinas

Investigation of the Protective Effects of Taurine against Alloxan-Induced Diabetic Retinal Changes via Electroretinogram and Retinal Histology with New Zealand White Rabbits

The purpose of this study was to investigate the protective role of orally administered taurine against diabetic retinal changes via electroretinogram (ERG) and retinal histology on rabbits. Rabbits were randomly assigned into groups: Group I (vehicle administration only); Group II (diabetes: induced by 100 mg/kg alloxan injection); Group III (diabetes and fed with 200 mg/kg taurine); and Group IV (diabetes and fed with 400 mg/kg taurine). The body weight and blood glucose levels of the rabbits were monitored weekly. The ERG was measured on weeks 5 and 15. Retinal histology was analyzed in the end of the experiment. Results revealed that a taurine supplement significantly ameliorates the alloxan-induced hyperglycemia and protects the retina from electrophysiological changes. Group II showed a significant (P<0.05) change in the mean scotopic b-wave amplitude when compared to that of Group I, whereas the diabetic rabbits treated with taurine (Group III and IV) were analogous to Group I. Histologically, the amount of Bipolar and Müller cells showed no difference (P>0.05) between all groups and when compared with those of Group I. Our study provides solid evidences that taurine possesses an antidiabetic activity, reduced loss of body weight, and less electrophysiological changes of the diabetic retina

Hedyotis diffusa

Traditional Chinese medicine (TCM), which is the most common type of complementary and alternative medicine (CAM) used in Taiwan, is increasingly used to treat patients with breast cancer. However, large-scale studies on the patterns of TCM prescriptions for breast cancer are still lacking. The aim of this study was to determine the core treatment of TCM prescriptions used for breast cancer recorded in the Taiwan National Health Insurance Research Database. TCM visits made for breast cancer in 2008 were identified using ICD-9 codes. The prescriptions obtained at these TCM visits were evaluated using association rule mining to evaluate the combinations of Chinese herbal medicine (CHM) used to treat breast cancer patients. A total of 37,176 prescriptions were made for 4,436 outpatients with breast cancer. Association rule mining and network analysis identified Hedyotis diffusa plus Scutellaria barbata as the most common duplex medicinal (10.9%) used for the core treatment of breast cancer. Jia-Wei-Xiao-Yao-San (19.6%) and Hedyotis diffusa (41.9%) were the most commonly prescribed herbal formula (HF) and single herb (SH), respectively. Only 35% of the commonly used CHM had been studied for efficacy. More clinical trials are needed to evaluate the efficacy and safety of these CHM used to treat breast cancer

Comparison of Aspergillus-specific antibody cut-offs for the diagnosis of aspergillosis

BackgroundAspergillus diseases are frequently encountered in patients who are immunocompromised. Without a prompt diagnosis, the clinical consequences may be lethal. Aspergillus-specific antibodies have been widely used to facilitate the diagnosis of Aspergillus diseases. To date, universally standardized cut-off values have not been established. This study aimed to investigate the cut-off values of Aspergillus-specific antibodies and perform a narrative review to depict the geographic differences in the Taiwanese population.MethodsWe analyzed enrolled 118 healthy controls, 29 patients with invasive aspergillosis (IA), chronic pulmonary aspergillosis (CPA), and allergic bronchopulmonary aspergillosis (ABPA) and 99 with disease control, who were tested for Aspergillus fumigatus and Aspergillus niger-specific IgG and IgE using ImmunoCAP. 99 participants not fulfilling the diagnosis of IA, CPA, and ABPA were enrolled in the disease control group. The duration of retrieval of medical records from June 2018 to September 2021. Optimal cut-offs and association were determined using receiver operating characteristic curve (ROC) analysis.ResultsWe found that patients with CPA had the highest A. fumigatus-specific IgG levels while patients with ABPA had the highest A. fumigatus-specific IgE, and A. niger-specific IgG and IgE levels. In patients with CPA and ABPA, the optimal cut-offs of A. fumigatus-specific IgG and A. niger-specific IgG levels were 41.6, 40.8, 38.1, and 69.9 mgA/l, respectively. Geographic differences in the cut-off values of A. fumigatus-specific IgG were also noted. Specifically, the levels were different in eco-climatic zones.ConclusionWe identified the optimal cut-offs of Aspergillus-specific antibodies to facilitate a precise diagnosis of aspergillosis. The observed geographic differences of the antibody levels suggest that an eco-climatic-specific reference is needed to facilitate a prompt and accurate diagnosis of aspergillosis

Deferoxamine retinopathy: spectral domain-optical coherence tomography findings

Al-Djamiʿ li Ibn al-BaïtharNumérisation effectuée à partir d'un document de substitution