2,314 research outputs found
Coded Index Modulation for Non-DC-Biased OFDM in Multiple LED Visible Light Communication
Use of multiple light emitting diodes (LED) is an attractive way to increase
spectral efficiency in visible light communications (VLC). A non-DC-biased OFDM
(NDC OFDM) scheme that uses two LEDs has been proposed in the literature
recently. NDC OFDM has been shown to perform better than other OFDM schemes for
VLC like DC-biased OFDM (DCO OFDM) and asymmetrically clipped OFDM (ACO OFDM)
in multiple LEDs settings. In this paper, we propose an efficient multiple LED
OFDM scheme for VLC which uses {\em coded index modulation}. The proposed
scheme uses two transmitter blocks, each having a pair of LEDs. Within each
block, NDC OFDM signaling is done. The selection of which block is activated in
a signaling interval is decided by information bits (i.e., index bits). In
order to improve the reliability of the index bits at the receiver (which is
critical because of high channel correlation in multiple LEDs settings), we
propose to use coding on the index bits alone. We call the proposed scheme as
CI-NDC OFDM (coded index NDC OFDM) scheme. Simulation results show that, for
the same spectral efficiency, CI-NDC OFDM that uses LDPC coding on the index
bits performs better than NDC OFDM
Generalized Spatial Modulation in Indoor Wireless Visible Light Communication
In this paper, we investigate the performance of generalized spatial
modulation (GSM) in indoor wireless visible light communication (VLC) systems.
GSM uses light emitting diodes (LED), but activates only of them at
a given time. Spatial modulation and spatial multiplexing are special cases of
GSM with and , respectively. We first derive an analytical
upper bound on the bit error rate (BER) for maximum likelihood (ML) detection
of GSM in VLC systems. Analysis and simulation results show that the derived
upper bound is very tight at medium to high signal-to-noise ratios (SNR). The
channel gains and channel correlations influence the GSM performance such that
the best BER is achieved at an optimum LED spacing. Also, for a fixed
transmission efficiency, the performance of GSM in VLC improves as the
half-power semi-angle of the LEDs is decreased. We then compare the performance
of GSM in VLC systems with those of other MIMO schemes such as spatial
multiplexing (SMP), space shift keying (SSK), generalized space shift keying
(GSSK), and spatial modulation (SM). Analysis and simulation results show that
GSM in VLC outperforms the other considered MIMO schemes at moderate to high
SNRs; for example, for 8 bits per channel use, GSM outperforms SMP and GSSK by
about 21 dB, and SM by about 10 dB at BER
Preliminary phytochemical analysis & Invitro Antibacterial activity of Acacia catechu willd Bark against Streptococcus mitis, Streptococcus sanguis & Lactobacillus acidophilus
The objective of our study is to investigate the in vitro antibacterial activity of ethanolic  bark extract of Acacia catechu willd against selected oral microbes and to investigate the phytochemicals present in it. The inhibitory effect of the extract were tested against selected oral microbes by using the Macro broth dilution method .The ethanolic bark extract of Acacia catechu exhibited antibacterial activity against streptococcus mitis with minimum bactericidal concentration of 500µg/ml whereas the MBC for streptococcus sanguis and Lactobacillus acidophilus were found to be 1mg/ml, 5mg/ml,10mg/ml and the phytochemical analysis revealed the presence of tannins, flavonoids, amino acids , saponins, triterpenoids. The ethanolic  bark extract of Acacia catechu willd was found to be bactericidal in action against tested bacterial strains and these action may be due to the presence of phytochemical constituents in it.Â
Preliminary phytochemical analysis & Invitro Antibacterial activity of Acacia catechu willd Bark against Streptococcus mitis, Streptococcus sanguis & Lactobacillus acidophilus
The objective of our study is to investigate the in vitro antibacterial activity of ethanolic  bark extract of Acacia catechu willd against selected oral microbes and to investigate the phytochemicals present in it. The inhibitory effect of the extract were tested against selected oral microbes by using the Macro broth dilution method .The ethanolic bark extract of Acacia catechu exhibited antibacterial activity against streptococcus mitis with minimum bactericidal concentration of 500µg/ml whereas the MBC for streptococcus sanguis and Lactobacillus acidophilus were found to be 1mg/ml, 5mg/ml,10mg/ml and the phytochemical analysis revealed the presence of tannins, flavonoids, amino acids , saponins, triterpenoids. The ethanolic  bark extract of Acacia catechu willd was found to be bactericidal in action against tested bacterial strains and these action may be due to the presence of phytochemical constituents in it.Â
Spectrophotometric determination and estimation of minoxidil in tablet dosage form by UV
A simple, precise, accurate and economical UV spectrophotometric method has been developed and validated for the estimation of Minoxidil in the tablet dosage form. Minoxidil shows maximum absorbance at 279.4nm. The method was carried out by using 0.1N HCl as a solvent. The drug shows linearity from the concentration range of 1-6µg/ml and correlation coefficient was found to be 0.9992. The proposed method was statistically validated for precision, accuracy, ruggedness, robustness, the limit of detection, quantitation as per the ICH guidelines. Hence this method can be successfully applied for routine analysis of Minoxidil in bulk and tablet dosage form
AN ASSESSMENT OF QUALITY OF LIFE IN SWASAKASAM (BRONCHIAL ASTHMA) PATIENTS REPORTING AT AYOTHIDOSS PANDITHAR HOSPITAL – A CROSS SECTIONAL STUDY
Asthma is a chronic inflammatory disease of the small airways that affects all age groups. Asthma symptoms lead to impairment in the physical, emotional and social aspects of patient’s life. Bronchial asthma can be correlated to Swasakasam as per siddha text book Yugi vaithiya chinthamani 800. In Swasakasam patients, respiratory symptoms are important determinants of reduced health related quality of life. Evaluation of Health Related Quality of Life (HRQoL) is a primary outcome measure in patient with chronic disease. The objective of the study is to assess the HRQoL in Swasakasam patients and to evaluate the risk factors associated with it. It was a hospital based observational study of which 100 asthma patients were evaluated to quality of life who were reporting at OPD of Ayothidoss Pandithar Hospital, National Institute of Siddha (NIS) through Asthma Quality of Life Questionnaire (AQLQ). In this study, asthma affects females more than males (63% and 32%) and with 2% of male children. For the total patient population, there was a maximum limitation in physical activity domain (2.22±0.41) of HRQoL compared to other 3 domains. In case of sub score of all domains the mean of emotional function domain is lesser in female patients than male. Bronchial asthma significantly affects QOL. To reduce the asthma severity yoga, Pranayamam may be used adjunctively with standard medication in bronchial asthma patients and awareness should be given to improve their quality of life and to reduce the number of asthma attacks per week
YUGI’S CONCEPT OF GUNMAM PATIENTS REPORTING AT AYOTHIDOSS PANDITHAR HOSPITAL, NATIONAL INSTITUTE OF SIDDHA (NIS) - A CROSS SECTIONAL STUDY
According to Siddha system of medicine disease are numbered as 4448. One among them is Gunmam. Severe pain in the abdomen occurs as one of the symptoms and this makes the patient to bend forward in order to get relief from pain and hence the name is mentioned as Gunmam. As per sage Yugi, Gunmam is further classified into 8 types. The human body runs on the basis of Vatham, Pitham, Kabam and due to changes in the equilibrium of tri-dosha mankind acquires disease. As per Theraiyar Gunmam occurs due to vitiation of Vali thathu. Common symptoms of Gunmam are indigestion, vomiting, abdominal pain, abdominal distension, decrease body weight, loss of confidence. The signs and symptoms of Gunmam can be correlated to Acid Peptic Disease (APD). This study was undertaken to assess the incidence of different types of Gunmam patients reporting at OPD of Ayothidoss Pandithar Hospital. This is hospital based cross sectional study conducted in Ayothidoss Pandithar Hospital between months of May 2019 and July 2019. The study was given ethical approval by institutional Ethics Committee. The study included the completion of questionnaire which focuses on symptoms of eight types of Gunmam, thega ilakkanam, behavioural risk factors for Gunmam and physical measurements from randomly selected patients reporting to the OPD. Using Systematic random sampling method, 250 patients were selected from the OPD of Ayothidoss Pandithar Hospital. Statistical analysis was done using SPSS software. Among 250 Gunmam patients, 33.2% of subjects are Pitha thegi, 32.8% of subjects are Eri gunmam
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