Quadrature Phase Shift Keying (QPSK) Modulator Design using Multi-Port Network in Multilayer Microstrip-Slot Technology for Wireless Communication Applications

The design of the quadrature phase shift keying (QPSK) modulator by using a multi-port network is proposed in this article for the use in wireless communication applications. The multi-port network is in the form of multilayer microstrip-slot technology. This multi-port network is composed of three 3-dB rectangular-shaped directional couplers with virtual stubs and an equal power division divider with in-phase characteristic. The design is performed by applying a full-wave electromagnetic simulation software, CST Microwave Studio (CST MWS). Keysight’s Advanced Design System (ADS) is applied in analyzing and evaluating the QPSK constellation of the proposed modulator. This comparatively small size of proposed design has been fabricated, and its wideband performance of 2 to 6 GHz is verified

Automated characterization of single-photon avalanche photodiode

We report an automated characterization of a single-photon detector based on commercial silicon avalanche photodiode (PerkinElmer C30902SH). The photodiode is characterized by I-V curves at different illumination levels (darkness, 10 pW and 10 uW), dark count rate and photon detection efficiency at different bias voltages. The automated characterization routine is implemented in C++ running on a Linux computer.Comment: Have permission to post journal-formatted version on arXi

Performance of a multi-stack microchannel heat sink

The usage of a very large scale integrated circuits generate high heat fluxes and require an effective cooling system. A microchannel heat sink (MCHS) is one of the reliable cooling systems that had been applied. In terms of performance, a MCHS can be appraised by obtaining low total thermal resistance and pumping power. However, as the total thermal resistance decreases, the pumping power will increase. A few studies have been focused on the minimization of the thermal resistance and pumping power of a multi-stack MCHS. Optimization of two objective functions which are the total thermal resistance and pumping power has been done by using genetic algorithm. It is demonstrated that both objective functions can be minimized by optimizing two design variables which are the channel aspect ratio, α, and wall width ratio,β. It was found that the usage of a stacked configuration for the MCHS is able to reduce the total thermal resistance. From the optimization, it was found that the optimum number of stacks that can be implemented is three. With the three-stack configuration, the total thermal resistance found is 0.1180 K/W which is 21.8% less compared to the single-stack MCHS. However, the pumping power needed for the three-stack MCHS is increased by 0.17 % compared to single-stack which is 0.7535 W

How head and neck consultants manage patients’ emotional distress during cancer follow-up consultations : a multilevel study

Head and neck cancer (HNC) patients suffer substantial emotional problems. This study aimed to explore how utterance-level variables (source, type and timing of emotional cues) and patient-level variables (e.g. age, gender and emotional well-being) relate to consultants’ responses (i.e. reducing or providing space) to patient expressions of emotional distress. Forty-three HNC outpatient follow-up consultations were audio recorded and coded, for patients’ expressions of emotional distress and consultants’ responses, using the Verona Coding Definitions of Emotional Sequence. Multilevel logistic regression modelled the probability of the occurrence of consultant reduce space response as a function of patient distress cue expression, controlling for consultation and patient-related variables. An average of 3.5 cues/concerns (range 1–20) was identified per consultation where 84 out of 152 total cues/concerns were responded by reducing space. Cue type did not impact on response; likewise for the quality of patient emotional well-being. However, consultants were more likely to reduce space to cues elicited by patients, as opposed to those initiated by themselves. This reduced space response was more pronounced as the consultation continued. However, about 6 min into the consultation, this effect (i.e. tendency to block patients) started to weaken. Head and neck consultants’ responses to negative emotions depended on source and timing of patient emotional expressions. The findings are useful for training programme development to encourage consultants to be more flexible and open in the early stages of the consultation.PostprintPeer reviewe

Numerical simulation of flow surrounding a thermoacoustic stack:single-stack against double-stack plate domain

Over the last few decades, numerical simulation has fast become an effective research tool in analyzing internal and external fluid flow. Much of the unknowns associated with microscopic bounded and unbounded fluid behavior generally not obtainable via experimental approach can now be explained in details with computational fluid dynamics modeling. This has much assist designers and engineers in developing better engineering designs. However, the choice of the computational domain selected plays an important role in exhibiting the correct flow patterns associated with changes in certain parameters. This research looked at the outcomes when two computational domains were chosen to represent a system of parallel stack plates in a thermoacoustic resonator. Since the stack region is considered the “heart” of the system, accurate modeling is crucial in understanding the complex thermoacoustic solid-fluid interactions that occur. Results showed that although the general flow pattern and trends have been produced with the single and double plate stack system, details of a neighboring solid wall do affect the developments of vortices in the stack region. The symmetric assumption in the computational domain may result in the absence of details that could generate an incomplete explanation of the patterns observed such as shown in this study. This is significant in understanding the solid-fluid interactions that is thermoacoustic phenomena

Esports Analytics on PlayerUnknown's Battlegrounds Player Placement Prediction using Machine Learning

PUBG (PlayerUnknown’s Battlegrounds) is a video game that has become popular in the past year. This paper aims to predict the placement of PUBG players during the match by detecting the influential features set that can impact the outcome of the PUBG game and build the best prediction model using a machine learning approach. In this study, the dataset is taken from Kaggle, which has 29 attributes that are categorized into one label (winPlacePerc). The training set has divided into five sets with each set has 6000 instances. The decision tree regression model was applied to find the optimum prediction. Other regression models such as Linear Regression and Support Vector Machine are also utilized to compare with the decision tree model’s result. Based on the result analysis, the walkDistance feature was deemed as the most significant factor influencing the results of a PUBG game. Furthermore, there are other common features obtained from the five datasets that represent the crucial factors which are boosts, DBNOs, killPlace, kills, rideDistance and matchDuration. From the three regression models, the Support Vector Machine model built on the significant features has the best performance in terms of RMSE value while the Decision Tree Regression model has the fastest prediction speed among these regression models

Training needs assessment in Malaysia: Exercise held at Kuala Lampur and Kota Bharu from 13th October 1989

Training / Irrigation / Evaluation / Malaysia

Uji Aktivitas Hepatoprotektif Teh Hijau Kombucha Pada Tikus Putih Yang Diinduksi Parasetamol

Paracetamol is an analgesic-antipyretic drug that has hepatotoxic effect when taken in high doses. Paracetamol toxicity is due to the formation of toxic metabolites when a part of it is metabolized by cytochrome P450. This study was designed to evaluate the hepatoprotective activity of green kombucha tea (GKT) in wistar albino rats. Acute liver injury was induced by paracetamol (750mg/kg, b.w). GKT at the dose of 0.5, 1.0, and 1.5 ml, p.o was administered for 7 days. The biochemical parameters of liver such as serum glutamate oxaloacetate transaminase (SGOT), glutamate pyruvate transaminase (SGPT) levels were measured using spectrophotometer. Finally, the liver weight (Wt/100g b.w) of rats were recorded. GKT in all doses prevented the increase of liver weight significantly (p<0.05) when compared with paracetamol treated rats. The dose 1.0 ml of GKT was found to be the most effective than the other dose (0.5 and 1.5 ml). GKT produced hepatoprotective effect significantly (p<0.05) by decreasing the activity of serum enzyme such us SGOT and SGPT. The 1.0 ml dose of GKT also found to be the most effective dose to decrease the levels of SGOT and SGPT. It is concluded that the Green kombucha tea possesses good hepatoprotective activity

Marine Sourced Glycosaminoglycans ‘GAGs'

Globally, there is an uprising interest for availability of tangible, novel, added value, sustainable commercial exploitable therapeutic compounds from naturally derived sources. The paper will highlight bioactive compounds of therapeutic potential from marine sources such as polysaccharides, especially glycosaminoglycans. It is now well documented, and this effort combined with a green technological approach in sustainable natural biodiversity will allow the development of a new generation of therapeutics. Outsourcing for a biocompatible, non-mutational bioactive compound such as GAG's in a worldwide research and industrial agenda. Hence, the thorough understanding on how the biosynthesis, structure and function of complex glycosaminoglycans will reveal the polysaccharides from the marine environment could provide a valid alternative to traditional polysaccharides such as glycosaminoglycans