Browsing by Author "ISLAM, ASHRAFUL"

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A Survey on Dimensionality Reduction Techniques for Time-series Data
(Independent University, Bangladesh, 2023-06) ASHRAF, MOHSENA; ANOWAR, FARZANA; SETU, JAHANGGIR H.; CHOWDHURY, ATIQUL I.; AHMED, ESHTIAK; ISLAM, ASHRAFUL; MAMUN, ABDULLAH AL
Data analysis in modern times involves working with large volumes of data, including timeseries data. This type of data is characterized by its high dimensionality, enormous volume, and the presence of both noise and redundant features. However, the "curse of dimensionality" often causes issues for learning approaches, which can fail to capture the temporal dependencies present in time-series data. To address this problem, it is essential to reduce dimensionality while preserving the intrinsic properties of temporal dependencies. This will help to avoid lower learning and predictive performances. This study presents twelve different dimensionality reduction algorithms that are specifically suited for working with timeseries data and fall into different categories, such as supervision, linearity, time and memory complexity, hyper-parameters, and drawbacks.
EFFECT OF MORINGA LEAF EXTRACT ON GROWTH AND YIELD OF CHILI (Capsicum annuum L.)
(Sher-e-Bangla Agricultural University, Dhaka, Bangladesh, 2021-12) ISLAM, ASHRAFUL
The using of synthetics fertilizers to improve soil fertility and crop yield have adverse effect on soil and environment. Different organic material may use to reduce the use of chemical fertilizers. The main purpose of the study is to evaluate the effect of Moringa leaf extract (MLE) as a growth hormone on growth and yield of chili (Capsicum annum L.). The experiment was carried out at Agroforestry and environmental science research field of Sher-e-Bangla Agricultural University, Dhaka-1207 during the period from December, 2021 to May, 2022. This pot experiment was laid out in Randomized block design (RCBD). This experiment comprised of six treatment with seven replications. Treatments were T0, T1, T2, T3, T4, T5 with 0, 15, 30, 45, 60, 75 ml MLE solution respectively. This single factor experiment was done by using chili (BARI Morich-2). The result revealed that different level of Moringa leaf extract showed significant variation on parameters studied during the experiment. The result indicated that T5 treatment showed highest results on plant height (84.72 cm), leaf number (191.78), number of branches (14.0), stem diameter (2.12 cm), days of first flowering (51.42 days), fresh weight of shoot (364.93 g), fresh weight of root (84.22 g), dry weight of shoot (51.48 g), dry weight of root (15.77 g), number of fruits (194.4), length of fruits (11.17 cm), weight of fruits (311.32 g), yield of fruits (19.60 tha-1). The result also indicated that T0 treatment showed lowest growth and yield contributing all the parameters. Growth and yield of chili plant gradually increased with the increased of MLE. It can be stated that higher dose of MLE is positively correlated with growth and yield of chili. So, T5 treatment can recommend to obtain superior growth and yield of chili plant.
Efficiency Improvement Of Dc To Dc Boost Converter With Two Input Power Sources For Renewable Energy Application
(Military Institute of Science and Technology, 2014-12) MD. MEHADEE HASAN, LT; ISLAM, ASHRAFUL; ISLAM SHOUMY, SANZANA
Most power electronic systems, the instantaneous input and output power vary by time and are not exactly identical with each other. Hence providing a good match between them is a complicated task to deal with if not impossible. A DC-to-DC converter is a device that accepts a DC input voltage and produces a DC output voltage. Typically the output produced is at a different voltage level than the input. The aim of this study is to develop a high-efficiency converter with two input power sources for a distributed power generation mechanism. There are different type of methods to get high voltage and efficiency of a dc-dc boost converter such as interleaving, switch capacitor based, SMPS etc. The proposed converter can boost the varied voltages of different power sources in the sense of hybrid power supply to a stable output dc voltage for the load demand. According to various situations, the operational states of the proposed converter can be divided into two states including a single power supply and a dual power supply. In the dual power-supply state, the input circuits connected in series together with the designed pulse width modulation can greatly reduce the conduction loss of the switches.
SCREENING OF SOME BRINJAL HYBRIDS AND VARIETIES AGAINST BRINJAL SHOOT AND FRUIT BORER
(DEPARTMENT OF ENTOMOLOGY, SHER-E-BANGLA AGRICULTURAL UNIVERSITY, DHAKA., 2014-06) ISLAM, ASHRAFUL
An experiment was conducted in the experimental field of Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka, from mid-November, 2013 to May, 2014 to study varietal performance of brinjal against brinjal shoot and fruit (Leucinodes orbonalis Guinee.). The varieties are BARI brinjal 1, BARI hybrid brinjal 3, BARI brinjal 3, BARI hybrid brinjal 4, BARI brinjal 5, BARI brinjal 6, BARI brinjal 7, BARI brinjal 8, BARI brinjal 9, BARI brinjal 10 .The experiment was laid out in single factor Randomized Complete Block Design (RCBD) with three replications. The data were recorded on shoot infestation; fruit infestation by number and weight at vegetative, early, mid and late fruiting stages; plant and yield related attributes as well as yield of brinjal. Among all varieties, V6 (BARI brinjal 6) showed best performance against brinjal shoot and fruit borer and reduced the highest percent of shoot infestation, fruit infestation by number and weight in early, mid and late stages (1.18, 3.54 and 2.74%, respectively) throughout the growing period of brinjal. Besides, BARI hybrid brinjal 3 showed best performance in case of single fruit weight, fruit number per plant and yield throughout the growing period of brinjal. In case of yield, BARI hybrid brinjal gave highest production. On the other hand, BARI brinjal 7 showed lowest performance in case of shoot infestation, infestation and fruit infestation by number and by weight, thrichome hair density and thorn on stem and leaves. It was revealed from the experiments, V6 (BARI brinjal 6) showed best result and V7 (BARI brinjal 7) showed least performance in case of shoot infestation, fruit infestation by number and weight in early, mid and late stages, number of fruits per plant and single fruit weight and yield. Brinjal yield was increased due to increases of number of branches per plant, number of leaf per plant and plant height.