Bivariate Beta-LSTM

Long Short-Term Memory (LSTM) infers the long term dependency through a cell state maintained by the input and the forget gate structures, which models a gate output as a value in [0,1] through a sigmoid function. However, due to the graduality of the sigmoid function, the sigmoid gate is not flexible in representing multi-modality or skewness. Besides, the previous models lack modeling on the correlation between the gates, which would be a new method to adopt inductive bias for a relationship between previous and current input. This paper proposes a new gate structure with the bivariate Beta distribution. The proposed gate structure enables probabilistic modeling on the gates within the LSTM cell so that the modelers can customize the cell state flow with priors and distributions. Moreover, we theoretically show the higher upper bound of the gradient compared to the sigmoid function, and we empirically observed that the bivariate Beta distribution gate structure provides higher gradient values in training. We demonstrate the effectiveness of bivariate Beta gate structure on the sentence classification, image classification, polyphonic music modeling, and image caption generation.Comment: AAAI 202

Frequency-Based Decentralized Conservation Voltage Reduction Incorporated Into Voltage-Current Droop Control for an Inverter-Based Islanded Microgrid

Conservation voltage reduction (CVR) aims to decrease load demands by regulating bus voltages at a low level. This paper proposes a new strategy for decentralized CVR (DCVR), incorporated into the current-based droop control of inverter-interfaced distributed energy resources (IDERs), to improve the operational reliability of an islanded microgrid. An $I_{dq}$ controller is developed as an outer feedback controller for each IDER, consisting of $I_{d}$ $V$ controllers for the DCVR and $I_{d}$ $\omega$ and $I_{q}$ $V$ controllers for power sharing. In particular, the $I_{d}$ $V$ controllers adjust the output voltages of the IDERs in proportion to the frequency variation determined by the $I_{d}$ $\omega$ controllers. This enables the output voltages to be reduced by the same amount, without communication between the IDERs. The $I_{q}$ $V$ controllers are responsible for reactive power sharing by adjusting the voltages while taking into account the $I_{d}$ $V$ controllers. Small-signal analysis is used to verify the performance of the proposed DCVR with variation in the $I_{d}$ $\omega$ and $I_{q}$ $V$ droop gains. Case studies are also carried out to demonstrate that the DCVR effectively mitigates an increase in the load demand, improving the operational reliability, under various load conditions determined by power factors and load compositions.11Ysciescopu

Optimal Voltage Control Using an Equivalent Model of a Low-Voltage Network Accommodating Inverter-Interfaced Distributed Generators

The penetration of inverter-based distributed generators (DGs), which can control their reactive power outputs, has increased for low-voltage (LV) systems. The power outputs of DGs affect the voltage and power flow of both LV and medium-voltage (MV) systems that are connected to the LV system. Therefore, the effects of DGs should be considered in the volt/var optimization (VVO) problem of LV and MV systems. However, it is inefficient to utilize a detailed LV system model in the VVO problem because the size of the VVO problem is increased owing to the detailed LV system models. Therefore, in order to formulate and solve the VVO problem in an efficient way, in this paper, a new equivalent model for an LV system including inverter-based DGs is proposed. The proposed model is developed based on an analytical approach rather than a heuristic-fitting one, and it therefore enables the VVO problem to be solved using a deterministic algorithm (e.g., interior point method). In addition, a method to utilize the proposed model for the VVO problem is presented. In the case study, the results verify that the computational burden to solve the VVO problem is significantly reduced without loss of accuracy by the proposed model.11Ysciescopu

Colour-encoded electroluminescent white light-emitting diode Eenabled by Perovskite-Cu-In-S quantum composites

Solution-processed quantum dot (QD) white light-emitting diodes (WLEDs) have received much attention as a viable light source in the next-generation large-area ambient lighting, flexible photonics and full-colour display backlighting technologies. Attributable to their solution processibility, tunable colour temperature, high quantum efficiency and high photostability, considerable research efforts have been spent on accumulating new insights into the materials and device architecture design for high-performance QD WLEDs. At present, prevalent research on WLEDs focuses on using QDs as a photoluminescence colour converter or using purely narrow linewidth QD LEDs to complement white colour spectra, which is not energy efficient as well as challenging to achieve Eye Comfort ambient colour coding. Herein, a quantum composite made from hybridising perovskite (CsPbBr3 and CsPb(Br1-xClx)3) and CuInS2 (CIS) QDs is proposed as a colour-encoded electroluminescence layer, which underpins good white colour temperature and bias stability for ambient lighting. Instead of using solely sharp emission QDs to match the white light spectra, broad light emission spectrum CIS QDs are used for colour temperature toning. In addition, the mixed-halide perovskite CsPb(Br1-xClx)3 QDs are successfully synthesised through a noninvasive halide ion exchange method associated with trimethylsilyl chloride additives, which provide a good colour purity in blue and green electroluminescence region. This rational-designed QD composites enable the as-prepared WLED electroluminescence spectra to match the ideal ambient light Commission International de l’Éclairage 1931 (CIE) colour coordinates with a mean value of 0.33, 0.34. Moreover, as-prepared WLEDs show a turn-on voltage of 4 V with negligibly small leakage current, good colour stability and electrical bias tolerance even under a broad range of driving voltages. Our results herald the advent of molecular level hybridisation of different quantum materials for high-performance electroluminescence white colour toning

Assessment of Allergic Rhinitis Websites in Korea

Objectives. The internet has become an important source of medical information and a great amount of information related to allergic rhinitis (AR) is available on the internet. However, the quality of this information is still a matter of debate. Therefore, this study was conducted to assess the AR-related information on Korean websites. Methods. The key word "allergic rhinitis" was entered into 4 popular search engines, and this led to identifying 40 websites. After being categorized according to authorship, the informational value of these websites was evaluated using 4 different assessment tools such as the Journal of the American Medical Association (JAMA) benchmarks, the DISCERN questionnaire, the Allergic Rhinitis and its Impact on Asthma (ARIA) 2008 Update and the Health On the Net (HON) code. Results. The 40 websites containing AR-related information were categorized according to their authorship as Western physician: 20, Oriental physician: 14, commercial: 1, and others: 5. The mean citation frequencies of the JAMA benchmarks and the ARIA 2008 Update concepts was 1.23 out of 4 and 4.33 out of 8, respectively, while the mean DISCERN score was 1.92 out of 5. When the websites were evaluated based on the type of authorship, the mean citation frequencies of the AMA 2008 Update concepts were Western physician: 5.35, Oriental physician: 2.64. Additionally, three websites authored by Western physicians and 13 authored by Oriental physicians contained unreliable information. Among these 16 websites, only 3 websites met the requirements for the HON code "Justification". Conclusion. AR-related information available on Korean websites is of variable quality and not all of the information provided is justifiable. Thus, performing surveillance of the medical information on these websites is necessary. Furthermore, common criteria that can be used to evaluate the websites created by both Western and Oriental physicians are also needed.Bousquet J, 2008, ALLERGY, V63, P8*HLTH NET FDN, 2006, HLTH NET COD COND VESILVA LVE, 2005, BRAZILIAN J OTHORHIN, V71, P590Park HW, 2004, J KOREAN MED SCI, V19, P364Winker MA, 2000, JAMA-J AM MED ASSOC, V283, P1600Charnock D, 1999, J EPIDEMIOL COMMUN H, V53, P105Silberg WM, 1997, JAMA-J AM MED ASSOC, V277, P1244

Imaging Features of Gray-Scale and Contrast-Enhanced Color Doppler US for the Differentiation of Transient Renal Arterial Ischemia and Arterial Infarction

No publisher copyright information found in the SHERPA/RoMEO list.OBJECTIVE: To characterize the imaging features on gray-scale and contrast-enhanced color Doppler US images which differentiate renal ischemia from renal infarction. MATERIALS AND METHODS: The segmental renal arteries of eight healthy rabbits were surgically ligated. In four of these rabbits, the ligated renal artery was released 60 minutes after arterial occlusion to cause transient ischemia. In the remaining four rabbits, the arterial ligation was retained to cause a permanent infarction. The gray-scale and contrast-enhanced color Doppler US imaging features of the involved renal parenchyma of both ischemia and infarction groups were compared with respect to the presence or absence of parenchymal swelling, echogenicity changes, tissue loss and perfusion defects. RESULTS: Parenchyma swelling, echogenic changes, tissue loss and perfusion defects were found to be more extensive in the infarction than the ischemia group. The hyperechoic areas reperfused with blood flow recovered normal echogenicity and perfusion, whereas the hyperechoic areas without reperfusion became renal infarcts. CONCLUSION: Gray-scale and contrast-enhanced color Doppler US showed that the hyperechoic areas with reperfusion may reverse to normal parenchyma and allow the differentiation of renal ischemia from renal infarction

Epigallocatechin-3-gallate protects toluene diisocyanate-induced airway inflammation in a murine model of asthma

AbstractEpigallocatechin-3-gallate (EGCG), a major form of tea catechin, has anti-allergic properties. To elucidate the anti-allergic mechanisms of EGCG, we investigated its regulation of matrix metalloproteinase (MMP-9) expression in toluene diisocyanate (TDI)-inhalation lung tissues as well as TNF-α and Th2 cytokine (IL-5) production in BAL fluid. Compared with untreated asthmatic mice those administrated with EGCG had significantly reduced asthmatic reaction. Also, increased reactive oxygen species (ROS) generation by TDI inhalation was diminished by administration of EGCG in BAL fluid. These results suggest that EGCG regulates inflammatory cell migration possibly by suppressing MMP-9 production and ROS generation, and indicate that EGCG may be useful as an adjuvant therapy for bronchial asthma