Download Latest Complete Journal - JST Vol. 28 (2) Apr. 2020
Foreword by the Chief Executive Editor
No.ArticlesDownloads
1
Full Article
(Downloads: 92)
Abstract (Viewed: 8)Seagrass were flowering plants that grow entirely under the sea. Seagrass were a significant element in coastal habitats such as Bintan waters because it acts as a protective beach. Seagrasses have the capacity to stabilize the bottom waters of sediments and were able to generate sediments that can fertilize the waters. Seagrass can be a reference in coastal area to improve the stability of the coastal environment. Seagrass beds are useful for a protected area for tiny organisms, a spawning location for aquatic biota, and a location for juvenile and larval enlargement. Distribution of seagrass abundance are essential to understand because they can define coastal regions whether they are harmed or not. Seagrass surveillance techniques were still using divers with restricted coverage of the study region. For this reason, an acoustic method was used through this research to detect seagrass and the habitats that it occupied. It can be concluded that the acoustic method can measure sound intensity or acoustic backscatter from seagrass and their habitat. The height of the seagrass can be evaluated depending on the acoustic reflection value of the seagrass. There were 3 seagrass groups based on percent closure in the research place, which were tiny to none of the seagrass groups, unusual seagrass groups, and many seagrass groups. Seagrass was mostly found in good sedimentary habitats. The increase in the quantity of manually calculated seagrass biomass was accompanied by a rise in the value of acoustic backscattering intensity. The overall accuracy of the seagrass species using the acoustic technique is 87 %.Backscatter, biomass, hydroacoustics, seagrass
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(Downloads: 42)
Abstract (Viewed: 2)The tone of peking 1, 2, 3, 5, 6, 1’ was investigated using time-frequency analysis (TFA). The frequencies were measured using PicoScope oscilloscope, Melda analyzer in Cubase version 9 and Adobe version 3. Three different approaches for time-frequency analysis were used: Fourier spectra (using PicoScope), spectromorphology (using Melda analyzer) and spectrograms (using Adobe). Fourier spectra only identify intensity-frequency within entire signals, while spectromorphology identify the changes of intensity-frequency spectrum at fixed time and Adobe spectrograms identify the frequency with time. PicoScope reading produces the spectra of the fundamental and overtone frequencies in the entire sound. These overtones are non-harmonic since they are non-integral multiples of the fundamental. The fundamental frequencies of peking 1, 2, 3, 5, 6 were 1066Hz (C6), 1178Hz (D6), 1342Hz (E6), 1599Hz (G6) and 1793Hz (A6) respectively while peking 1’ was 2123Hz (C7) i.e. one octave higher than peking 1. Melda analyzer reading proved that all peking sustained the initial fundamental frequency and overtone at t=0 until 2s. TFA from Adobe reading provides a description of the sound in the time-frequency plane. From TFA, peking 1, 2 and 6 exhibited a much gentler attack and more rapid decay than peking 3, 5 and 1’.FFT, fundamental, gamelan, overtones frequencies, peking
3
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(Downloads: 34)
Abstract (Viewed: 3)Gamelan in general is categorized as a group of gongs. This traditional Malay gamelan ensemble is in a slendro scale i.e. five notes per octave. The rhythms, pitch, duration and loudness classify the various groups of gongs such as bonang, kenong, gender, peking and gambang. The cast bronze peking, kenong and bonang were chosen from a range of Malay gamelan ensemble from Universiti Malaysia Sarawak (UNIMAS), Universiti Putra Malaysia (UPM), Universiti Kebangsaan Malaysia (UKM) and Universiti Teknologi Mara (UiTM). The sounds were recorded by PicoScope Oscilloscope. The PicoScope software displays waveform and spectrum in time and frequency domain respectively. The peking lowest and highest frequencies from UiTM were 293 Hz and 1867 Hz, from UPM were 644 Hz and 1369 Hz, from UKM were 1064 Hz and 2131 Hz and from UNIMAS were 1072 Hz and 2105 Hz respectively. The kenong lowest and highest frequencies from UiTM were 259 Hz and 463 Hz, from UPM were 294 Hz and 543 Hz, from UKM were 300 Hz and 540 Hz and from UNIMAS were 293 Hz and 519 Hz respectively. The fundamental frequencies of bonang from UPM were higher than that of UKM, UiTM and UNIMAS. The harmonics were not successive but interrupted by another frequency. The harmonics of each bonang was similar except for gamelan from UKM.Bonang, fundamental frequencies, kenong, overtone, peking
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(Downloads: 43)
Abstract (Viewed: 5)The need for accurate seafloor maps is increasing along with the increase in marine activities, such as dredging, construction of buildings on the coast and offshore, and navigation of ships to prevent shipwrecks while sailing. The hydroacoustic technology used in this study is the multibeam echosounder system (MBES), which is the most advance acoustic instrument today. MBES can sweep very large areas in a short time, so that the survey costs can be reduced. The aim of this research was firstly to classify the seabed sediment in G-Island, Jakarta Bay using supervised classification technique. Secondly, to analyze the acoustic characteristic of the seabed sediment and compare it with the physical characteristic of the sediment.This research was conducted on October 31st to November 5th 2016 in the waters of G-Island, Jakarta Bay. In this study, supervised classification techniques were applied. The supervised classification techniques used in this research was Support Vector Machine (SVM). SVM produces classifications with 5 main classes, namely clay, fine silt, medium silt, coarse silt and fine sand. The overall accuracy value of the SVM method was 80.25% with the Kappa coefficient value of 0.2031 which is categorized into the fair class in its classification.Jakarta Bay, multibeam echosounder, supervised classification, support vector machine
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(Downloads: 24)
Abstract (Viewed: 6)Previous studies have indicated that the pipe-surface-mounted helical strakes effectively reduce vortex-induced vibration (VIV) under a uniform flow application, particularly during the lock-in region. Since VIV experiments are time-consuming, observation is generated with an interval helical strakes parameter in pitch and height to lessen tedious procedures and repetitive post-processing analyses. The aforementioned result subset is insufficient for helical strakes design optimisation because the trade-off between the helical strakes dimension, lock-in region and flow velocity are non-trivial. Thus, a parametric model based on an improved recursive least squares (RLS) parameter estimation technique is proposed to define the statistical relationship between input, or strakes and pipe dimension, and output, or VIV amplitude ratio. As results suggested, revised RLS estimated VIV model demonstrated an optimal prediction with the highest coefficient of determination and lowest Integral Absolute Error. The feasibility of VIV parametric model was validated by embed into Genetic Algorithm (GA) as the fitness function to acquire a desirable helical strakes dimension with minimum VIV amplitude. The rapid generation of optimal helical strakes dimension which returned the highest VIV suppression implied a superior simulation method compared to the experimental outcome.Genetic algorithm, helical strakes, recursive least squares, vortex-induced vibration
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(Downloads: 26)
Abstract (Viewed: 10)Cocoa (Theobroma cacao L) is a tropical plant that is widely used as a basic ingredient in chocolate production. The quality and taste of chocolate are greatly influenced by the stages and processes of post-harvest handling. Some post-harvest processes that are recognized for improving cocoa quality are pod storage, fermentation, and drying. The quality of cocoa beans can be known based on several physical and chemical parameters, including the color and pH of cocoa beans. This study aimed to analyze the effect of pod storage before fermentation (X1), aeration rate (X2) and aeration mode (X3) during the fermentation process on pH (Y1), chroma (Y2), and hue (Y3) of cocoa beans after fermentation and drying. Response surface methodology (RSM) was used to observe the relationships among the X1, X2, X3 variables and the Y1, Y2, and Y3 of dried cocoa beans, with the following treatments: X1 = 1; 5; 9 days, X2 = 0.2; 0.3; 0.4 liters/minute, X3 = intermittent 1; intermittent 2; and continue. The pH, chroma and hue of dried cocoa beans were: 4.873-6.517, 9.99-32.20, and 28.85-71.53, respectively. Furthermore, analysis of variance showed that pod storage before fermentation process significantly affected the hue but did not significantly affect the pH and chroma. The aeration rate had a significant effect on the pH and hue but did not have a significant effect on the chroma, while the aeration mode had no significant effect on the pH, chroma, and hue of dried cocoa beans.Aeration, cocoa bean fermentation, color L* a* b*, pH, pod storage
7
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(Downloads: 19)
Abstract (Viewed: 3)Numerous bridges fail all over the world every year because of ignoring the role of hydraulic factors, including flow and scour patterns in bridge designs. Hence, investigation of the flow pattern around intact and damaged bridge piers gains significant importance. This study provided experimental and numerical investigations of the flow pattern around damaged and intact bridge piers (short cylindrical and pillar elements). This topic is applicable to flooding conditions of rivers when and where the remainders of bridges and other structures on the river path could affect the flow pattern, making further flow pattern investigations under such conditions necessary. The experiments had been conducted in a straight channel with a length of 12 meters in Kerman, Iran. To collect the three dimensional flow velocity components, Acoustic Doppler Velocimetry (ADV) was employed. Further, Particle Image Velocimetry (PIV) was utilized to compare the results of ADV. SSIIM software helped model the flow in this study, and Navier-Stokes equations and k-ε turbulent model was used for solving the flow field. Generally, the results obtained through the comparisons are indicative of an appropriate correspondence between the numerical and the experimental data. The results indicated that installing the piers along the channel resulted in displacement of the maximum bed shear stress from the last one-third zone of the channel to mid-channel. Also, the maximum bed shear stress increased by 72% in comparison to the case with no piers installed. Moreover, the maximum water level variations occurred in the case with both intact and damaged piers installed, where there was water level reduction downstream and water level increase upstream of the pier.3D flow velocity, acoustic Doppler velocimetry, bed shear stress, bridge piers, experimental model, particle image velocimetry, SSIIM
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(Downloads: 26)
Abstract (Viewed: 2)Maximum k Satisfiability logical rule (MAX-kSAT) is a language that bridges real life application to neural network optimization. MAX-kSAT is an interesting paradigm because the outcome of this logical rule is always negative/false. Hopfield Neural Network (HNN) is a type of neural network that finds the solution based on energy minimization. Interesting intelligent behavior has been observed when the logical rule is embedded in HNN. Increasing the storage capacity during the learning phase of HNN has been a challenging problem for most neural network researchers. Development of Metaheuristics algorithms has been crucial in optimizing the learning phase of Neural Network. The most celebrated metaheuristics model is Genetic Algorithm (GA). GA consists of several important operators that emphasize on solution improvement. Although GA has been reported to optimize logic programming in HNN, the learning complexity increases as the number of clauses increases. GA is more likely to be trapped in suboptimal fitness as the number of clauses increases. In this paper, metaheuristic algorithm namely Artificial Bee Colony (ABC) were proposed in learning MAX-kSAT programming. ABC is swarm-based metaheuristics that capitalized the capability of Employed Bee, Onlooker Bee, and Scout Bee. To this end, all the learning models were tested in a new restricted learning environment. Experimental results obtained from the computer simulation demonstrate the effectiveness of ABC in modelling MAX-kSAT.Artificial bee colony, exhaustive search method, genetic algorithm, Hopfield neural network, maximum k satisfiability
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(Downloads: 23)
Abstract (Viewed: 2)This study aims to evaluate a continuous flow model that involves a ramp area at kilometer 31.6 on the highway from Shah Alam to Kuala Lumpur, to analyze the findings of numerical results of instantaneous speed ratios and to observe the convergence patterns for each section. The continuous flow model assumes traffic flow to be similar to the heat equation in regard to the concept of the one-dimensional viscous flow of a compressible fluid. For the methodology, for solving an initial value-boundary value problem, an initial condition together with a set of boundary conditions are required to solve the partial differential equation. The boundary conditions are chosen to assess the suitableness of the design of the entrance ramp in Malaysia, which is for right hand drive traffic. Highway traffic data were collected on the tapered acceleration lane and obtained by the videotaping method. The Maple programming language was used to write a numerical code in order to evaluate the instantaneous speed ratio in terms of a Fourier series. Our results show that the realistic results of instantaneous speed ratios on the ramp at kilometer 31.6 from Shah Alam to Kuala Lumpur are acceptable when compared to the theoretical results. Therefore, a very minimal collision rate is expected due to the well-designed ramp at kilometer 31.6 from Shah Alam to Kuala Lumpur. It is beneficial to study the mathematical model and theories of traffic flows on the merging area to enhance the efficiency of the traffic flowing on highways.Continuous flow model, heat equation, highway operation, macroscopic model, partial differential equation
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(Downloads: 27)
Abstract (Viewed: 1)The aim of this study is to develop a hybrid method using scale 3 Haar wavelets for obtaining the solution of coupled space-time fractional Burgers’ equation. Scale 3 Haar wavelets were used to estimate the solution by series approximation. Caputo and Riemann-Liouville definitions were used to handle the fractional derivatives and integrals in the problem. A quasi-linearization technique was implemented to handle the nonlinearity in the problems. Two examples of coupled space-time fractional Burgers’ equations were studied to analyze the performance of the proposed technique.Caputo derivatives, fractional coupled Burgers’ Equation, Quasi-linearization, Riemann-Liouville integration, scale 3 Haar wavelets
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(Downloads: 35)
Abstract (Viewed: 5)Solar drier is considered to be an important product used in the internet of things (IoT). It is used to dry different kinds of products used in agriculture or aquaculture. There are many factors that have different effects on the drying of items in the solar drier. The current study focused on the removal of the moisture ratio in the drying process for seaweed using solar drier. For this purpose, a dataset containing 1924 observations was used to study the effect of six different independent variables on the dependent variable. Moisture ratio removal (%) was considered to be dependent variable with ambient temperature, chamber temperature, collector temperature, chamber relative humidity, ambient relative humidity and solar radiation as independent variables. All possible models were used in the analysis till fifth order interaction terms. Hybrid model of LASSO with bisquare M was proposed for efficient selection of the model. The procedure based on four phases was used for efficient model selection and a comparison was made with other existing sparse and robust regression techniques. The result indicates that the proposed technique is better than other existing techniques in terms of mean squared error (MSE) and mean absolute percentage error (MAPE).All possible models, LASSO, model selection, robust, seaweed, selection criteria
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(Downloads: 19)
Abstract (Viewed: 1)The assessment of model fit is important in Structural Equation Modeling (SEM). Several goodness-of-fit (GoF) measures are affected by sample size and the number of parameters to be estimated. A large sample size is needed to test a complex model involving a large number of parameters to be estimated. One of the solutions to reduce the number of parameters to be estimated in a given model is by considering item parceling. The effects of item parceling on parameter estimates and GoF measures in a structural equation model was investigated via a simulation study. The simulation results indicate that the parameter estimates are closer to the true parameter values for the IL model whenever the distribution of data is normal but biased when the data is highly skewed. The parameter estimates for the IP model were found to be underestimated for both normal and non-normal data. The GoF measures were higher for the IP model. Additionally, the RMSEA was lower for the IP model when data were skewed. This shows that item parceling may improve GoF measures but the effect of exogenous on endogenous variable is underestimated. Application to a real data set confirmed the results of the simulation study.Goodness of fit, item parceling, parameter estimates, simulation, structural equation modeling
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(Downloads: 19)
Abstract (Viewed: 3)Cyclic menstrual pain, one of the most common gynecologic complaints, is a crucial issue. Unfortunately, only limited studies have focused on how to care for the menstrual pain in adolescents. This paper reports on the effective treatment for menstrual pain to mitigate or preclude menstrual pain perception, which is non-invasive to patients, in adolescents aged from 13 to 15 years. The treatment was conducted by positioning the patient in a supine position. Each patient was guided to take 30 minutes of breathing relaxation techniques. The use of Visual Analogue Scale (VAS) was intended to measure the subjects’ painfulness level. This study included 47 respondents whose menstrual pain was monitored in 30 minutes after the intervention. The findings of this study indicate a significant reduction of patients’ pain. The study suggests that further studies should focus on complementary treatments for overcoming menstrual pain.Adolescents, deep breathing, pain perception, primary dysmenorrhea
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(Downloads: 18)
Abstract (Viewed: 2)Inflammation and endothelial dysfunction are key components in atherogenesis. Should the status of these pro-atherogenesis factors be enhanced during prolonged confined space travel, specific countermeasures need to be instituted to prevent these processes to ensure safe outcome for astronauts during space expeditions. Six crew members were exposed to prolonged, confined isolation for 520 days. Standard exercise and diet regime were instituted throughout isolation phase. Age and gender-matched healthy, free living controls were recruited in parallel. Serial serum and whole blood were analysed for biomarkers of inflammation (hsCRP and IL-6) and endothelial activation (sICAM-1, sVCAM-1 and E-selectin). Flow-mediated dilatation (FMD) of the artery was performed following the standard protocols set by the International Brachial Artery Reactivity Task Force by trained personnel. There was decreased sVCAM-1 concentration in crew members compared to baseline. However, there was significant decrease in percentage dilatation from baseline in FMD of the brachial artery in the crew members. Percent change increment was observed in hsCRP while percent change reduction was seen in sVCAM-1. The enhanced inflammation and reduced endothelial function could possibly be attributed to the rigorous exercise instituted throughout the confinement period. Furthermore, possible haemoconcentration as a result of psychosocial stress and/ or exercise-induced physiological response could further explain elevations in hsCRP, and unlikely pathological. Furthermore, endothelial activation was attenuated during isolation, suggesting that the diet and exercise program instated throughout the period improved endothelial function.Atherogenesis, coronary artery disease, cosmonauts, endothelial activation, endothelial function, inflammation, MARS500
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(Downloads: 16)
Abstract (Viewed: 5)The abuse of antibiotics usage in bird industry has resulted in the emerging antibiotic resistant Enterococci worldwide which has posed a threat clinically to human health. The present study was to screen and identify the potential virulence agents in antibiotic resistance E. faecalis in bird industry in Borneo. Enterococcus bacteria collected from the birds’ faeces and indoor air inside ten birdhouses were identified to species level and their antibiotic resistance was checked using antibiotic susceptibility discs. Specific primers using PCR assay were intended for the detection of four potential virulence genes (ace, AS, efaA, gelE). Out of the thirty-seven Enterococci faecal bacteria, the prevailing bacteria found were Enterococcus qallinacum (51%), Enterococcus faecalis (35%) and Enterococcus harae (8%). The airborne bacteria were reported as Enterococcus faecalis (5%) and Enterococcus qallinacum (1%). Twenty-seven percent of isolates were reported to have Multiple Antibiotic Resistance (MAR) index ≥ 0.2 with 9 distinct resistance patterns formed. E. faecalis showed higher resistance to vancomycin. Virulence genes were successfully reported in the 15 E. faecalis isolates. Sixty-seven percent of isolates were detected positive for four virulence genes, 27% possessed three (AS, efaA, gelE) genes and 6% possessed two (ace, AS) genes. Antibiotic resistance and virulence genes detection were significantly correlated. These virulence genes or antibiotic resistance genes were important in the pathogenesis of E. faecalis infections.Antibiotic resistance, birds, Enterococcus faecalis, virulence
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(Downloads: 21)
Abstract (Viewed: 5)An ideal model organism for neurotoxicology research should meet several characteristics, such as low cost and amenable for high throughput testing. Javanese medaka (JM) has been widely used in the ecotoxicological studies related to the marine and freshwater environment, but rarely utilized for biomedical research. Therefore, in this study, the applicability of using JM in the neurotoxicology research was assessed using biochemical comparison with an established model organism, the zebrafish. Identification of biochemical changes due to the neurotoxic effects of ethanol and endosulfan was assessed using Fourier Transform Infrared (FTIR) analysis. Treatment with ethanol affected the level of lipids, proteins, glycogens and nucleic acids in the brain of JM. Meanwhile, treatment with endosulfan showed alteration in the level of lipids and nucleic acids. For the zebrafish, exposure to ethanol affected the level of protein, fatty acid and amino acid, and exposure to endosulfan induced alteration in the fatty acids, amino acids, nucleic acids and protein in the brain of zebrafish. The sensitive response of the JM toward chemicals exposure proved that it was a valuable model for neurotoxicology research. More studies need to be conducted to further develop JM as an ideal model organism for neurotoxicology research.Biochemical changes, Fourier Transform Infrared, Javanese medaka, model organism, zebrafish
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(Downloads: 18)
Abstract (Viewed: 3)An experimental study was conducted to assess marginal adaptation of various bulkfill composite materials, at cervical and occlusal margins of class II cavity preparation, applied by two different application techniques. Seventy-two (72) extracted premolar teeth were selected, prepared and filled with three different bulkfill composite materials, and inserted using incremental and bulk techniques. Specimens were thermocycled and bisected mesio-distally. All specimens were observed using a confocal fluorescence imaging microscope at 10× magnification. The data was analyzed using the Mann-Whitney U test. P < 0.05 was used to indicate statistically significant differences. The study results revealed that, no significant differences in marginal adaptation were detected among the two application techniques (incremental and bulkfill) at cervical margins p=1.000 and the occlusal margins p=0.639 with the lowest gap width formation achieved by X-trafil® bulkfill composite among the three different bulkfill composite filling materials, while FiltekTM Flowable composite material had the highest gap width. This study signifies that good marginal seal depends on the proper cavity preparation, good manipulation of filling materials and skill of the operator whatever is the application technique.Adaptation, application techniques, bulkfill composite materials, cervical margin, confocal microscope, occlusal margin
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(Downloads: 17)
Abstract (Viewed: 3)Skipjack tuna is a potential fish resource in the Makassar Strait, Bone Bay, and the Flores Sea waters, Indonesia. This fish is captured by fishermen using many kinds of fishing gear, and the most widely used is purse seine. The study was conducted from January to December 2018, aimed to compare the size structure of skipjack, productivity, and by-catch of purse seine inside and outside of Fish Aggregation Devices (FADs) areas. Fish length (cm, FL), annual production and trips data were collected from 10 ship owners in each fishing area, The main catch and by-catch weight data were obtained through direct observation of 30 trips each for 10 units, both of purse seines inside and outside of FADs areas in each study area. Comparative analysis of the catches of purse seines inside and outside of FADs areas included size structures using the Median Test (T test), productivity and by-catch using Mann-Whitney Test (T test). The results of the study explained that purse seiners inside FADs areas could increase business productivity, but caused an increase in small-sized skipjack and by-catch while purse seines outside of FADs areas caught less small size skipjack, low by-catch but low productivity.By-catch, FAD, productivity, size structure, skipjack purse seiner
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(Downloads: 26)
Abstract (Viewed: 5)Vertical greenery system (VGS) is a subset of urban green infrastructure that ameliorates thermal performance, potential energy savings, and urban heat island. Plants provide shadow effects through the absorption or filtration of the heat radiant, which respond to these issues. The frequent variable used to indicate the leaf mass of a plant is the leaf area index (LAI). There are two methods to measure LAI: direct and indirect methods. However, little attention was given to calculating the LAI using direct measurement in VGS. This study was undertaken to distinguish the LAI value from four plant species, i.e., Philodendron burle-marxii, Phyllanthus cochinchinensis, Nephrolepis exaltata, and Cordyline fructicosa ‘Miniature’ in the industrial city of Pasir Gudang. An image analysis tool was used to facilitate the measurement. The results showed the LAI values are highly dependent on the number of leaves. It also found plants that keep growing have the highest LAI value. Importantly, the characteristics of a plant need to be considered before planting in a shrub bed.Experimental study, leaf area index (LAI), plant species, vertical greenery system (VGS)
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(Downloads: 35)
Abstract (Viewed: 3)Hybrid ARQ (HARQ) has been identified as one of the most common optimal error control protocols. However, due to the complexity of the existing error codes, the use of HARQ in WSN can be viewed as energy-consuming, if it were not implemented properly. Multi coding as an extension to the HARQ protocol can be a promising method for improving a network plagued by high error rates. However, in implementing the error correcting codes for the better error rates, one may increase the overhead in terms of computational redundancies added to the transmitted bits, especially in a highly condensed network. This can lead to further degradation of the remaining energy and fluctuations in the Bit Error Rates (BER). Based on a previous study, other aspects must be considered to indicate the congestions present, rather than solely be dependent on the Signal to Noise Ratio (SNR). This paper proposes a congestion control based on the node density variation to control the congestion caused by different levels of numbers of nodes deployed, as well as the complexity of error correcting codes which were used in the network. We collected the BER values, as well as the remaining energy and latency, to study the optimal error correcting codes which varied with the codeword length, and the respective error correcting capabilities which suited the defined congested environments. Based on our results, our proposed multi coding assignment can adapt to the sudden changes in the channel condition, as well as improve the performance in terms of optimising the error rates, and the remaining energy across different types of channel conditions.Channel adaptation, channel estimation, error control protocol, multi coding scheme, wireless sensor networks

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