THz band multipath measurements and analysis

Abstract. The THz band is now becoming the core interest for many researchers as it offers massive bandwidth and high transmission rates. It is expected to be a solution to ongoing spectrum scarcity in the wireless communication world. Wave propagating through a channel is affected by various phenomena, especially in the case of non-line-of-sight (NLOS) condition. In this thesis work, measurement results on several NLOS propagation mechanisms such as reflection, diffraction, and penetration have been reported in the terahertz band ranging from 0.1 THz to 3 THz. Here, the primary focus is to measure the possible NLOS multipath, such as reflected, diffracted, and penetrated paths or a combination of multiple NLOS components. The goal is to evaluate and analyze the feasibility of those multipath in order to estimate the possibility to establish a communication link via such paths. The measurements have been conducted by using TeraView TeraPulse 4000, a measurement device that is based on THz time-domain spectroscopy (THz-TDS). Measurements were made under various NLOS propagation scenarios with several common indoor materials. Characteristics of the measured materials have also been reported. The results have been given as a function of frequency and measurement angles. Corresponding background theories and comparisons with the measurement results have also been investigated with subsequent analysis to check the relevance of the measurement results. The idea was to find possible multipath signals after various NLOS events while traveling through a channel and behavioural changes of the transmitted signal with the change of measurement scenarios. The measurement results agreed with the corresponding theories as expected. The THz band offers overall a decent NLOS wireless communication link between the receiver and transmitter at the lower angles

Milt quality determination of a critically endangered fish, olive barb (Puntius sarana, Ham.) in Bangladesh

The present study was aimed to evaluate the characteristics of the olive barb sperm. Milt was collected fortnightly from 49 male fish (mean weight 90.8 g and length 18.64 cm) from April to July in 2008. In the olive barb ejaculated milt, volume (µl/g), motility (%), duration of motility (s), concentration (x 10 super(10)/ml) and pH values were found to be 6.06±0.32, 88.27±0.71, 171.41±7.41, 5.16±0.05 and 7.75±0.04, respectively. Milt volume was significantly (P<0.05) correlated with sperm concentration. Milt volume, sperm concentration, motility and duration of motility significantly varied (P<0.05) during spawning season

ANCA-negative Churg-Strauss Syndrome

A rare and a disease of unknown etiology, Churg-Strauss syndrome (CSS) is a granulomatous necrotizing small vessel vasculitis characterized by the presence of asthma, sinusitis, and hypereosinophilia, which is initially described by Churg and Strauss in 1951. Because of its clinical and pathological features that overlap with those of the other anti-neutrophil antibody (ANCA)-associated systemic vasculitides (AASVs) and now the disease is classified as AASVs. The ANCA status may dictate the clinical phenotype. ANCA-positive patients are significantly more likely to have disease manifesta­tions associated with small-vessel vasculitis, including oecrotising glomemlonephritis, mononeuritis and purpura, whereas ANCA-negative cases predominantly likely to have cardiac and lung involvement. The objective of this case report is to point out the possibility of vasculitic rash in ANCA-negative CSS in a 35-year-old man and the disease rarely occurs in Bangladeshi population. We analyze the history, clinical examinations and relevant investigations related to the patient to establish the diagnosis in our department. The clinical scenario and biopsy help us to attain the diagnosis. But due to unavailability of patients' cohort we have limitations of comparison of ANCA status in Bangladeshi populations. Though ANCA-positive and ANCA-negative CSS differ phenotypically, primary therapy for both the conditions is systemic glucocorticoids. Additional immunosuppressive agents like cyclophosphamide, mycophenolate mofetil, azathioprine, rituxin1ab are occasionally added in patients with more advanced or refractory disease

Effect of stocking density on the growth and production of Thai Koi (Anabas testudineus) in Mymensingh region

The present study was conducted to optimize stocking density of Thai Koi (Anabas testudineus) in monoculture for a period of 98 days in 6 ponds of 0.2 ha each in a commercial farm under Mymensingh district. Three stocking densities of Thai Koi at 74,100, 86,450 and 98,800 ha-1 were assigned to treatments Ti, T2 and T3, respectively. Each treatment had two replicate ponds. The mean initial weight of Thai Koi was 0.2 g. A pelleted commercial diet containing 32-35% protein was fed twice daily at the rate of 20, 15, 12, 10, 8, 5 and 4% of the total body weight of the fish which was adjusted fortnightly. Feed conversion ratio (FCR) ranged from 1.73 to1.94 among the treatments. The water quality parameters were measured fortnightly and the ranges of temperature, pH, dissolved oxygen and total alkalinity were 27.5-29.6°C, 7.8 - 8.7, 5.1-6.2 mgC and 101-144 mgl..", respectively. Percent survival (%) of Thai Koi varied from 82.03 to 90.47. The weight gain of Thai Koi in Ti (91.0g) was significantly higher (P0.05) among the treatments. The achieved production in weight were 6,584.84, 6,388.29 and 5,700.31 kgha-lin T3, T2 and Ti, respectively. The production of Thai Koi was significantly higher (P<0.05) in T3 than those the T2 and Ti. But the highest net profit (Tk. 109.35 kgfish-1) was derived in Ti and lowest (Tk. 77..90 kgfish-1) in T3. The investment was rather highest in T3(Tk. 72.09 kgfish-1) and lowest in T1 (Tk 60.65 kgfish-1). That means the market value of per kg fish is decreasing in higher stocking density than the lower stocking density for its individual weight. Therefore, from the results of this study, it is concluded that for higher profit a total stocking density of 74100 ha "1 for Thai Koi (Anabas testudineus) monoculture in pond aquaculture system may be recommended

Value chain impact of the increased hilsa shad (Tenualosa ilisha) harvest in Bangladesh

Hilsa shad is the largest single fish species, contributing 12% of the total fish production in Bangladesh. Since the rapid decline of its harvest in early 2000, the government of Bangladesh took various initiatives to accelerate the hilsa production and introduced the hilsa fisheries management action plan in 2005. Under WorldFish led enhanced coastal fisheries project, implemented in partnership with the Department of Fisheries, the hilsa fishery reversed and experienced record harvest in 2016. Therefore, this study was undertaken to explore the contributions and benefits of this increased hilsa shad production among value chain actors. The results revealed that increased catches have significant impacts on the volumes of hilsa that were handled by the value chain actors, which depressed market price along the value chain. However, the increased amounts of hilsa harvested compensated for the reduced price and led to increased profits, increased household incomes of the value chain actors, and enhanced fish consumption at the household levels. The increased hilsa catch also had positive and significant impacts on credit repayment. Therefore, the incentive-based co-management system deserves continuation to improve the livelihood of the poor hilsa fishers, to increase the income of the value chain actors and to ensure a sustainable hilsa fishery for Bangladesh

Primary Data for the published paper entitled “Influence of seasons, habitat sanctuaries, gears and environmental variables on the catches of hilsa shad (Tenualosa ilisha) in Bangladesh waters”

Aim: Variations in catch per unit effort (CPUE) of hilsa (Tenualosa ilisha ) at different habitats (sanctuaries) of Bangladesh waters were observed to understand whether CPUE variations were due to differences in habitat complexity, environmental factors or both. Methodology: CPUE of hilsa data were collected from five different habitats in Bangladesh waters between July 2015 and June 2016. Various physico-chemical parameters were measured monthly and then examined for any relationship to CPUE. Results: The overall mean CPUE of hilsa from the investigated areas was estimated to be 7.93 ± 6.03 kg gillnet day. The monthly average values of CPUE was the highest in January 2016 amounting 11.63 ± 1.21 kg gillnet day and the lowest in March 2016 amounting 3.63 ± 0.83 kg gillnet day with significant differences among the months (p 0.05) with environmental variables and CPUE. Multiple regression analysis tests also indicated a weak overall correlation (62%) between environmental variables and CPUE of hilsa. Interpretation: Results likely indicate that habitat structure was more important in determining CPUE of hilsa (highest in Padma sanctuary) compared to environmental factors at the tested sites. This study emphasizes the need to conserve habitats that are often used as important fishing grounds for hilsa to ensure their adequate recruitment and ultimately sustainable management of this fisher

Primary Data for the published paper entitled “Catch trend and stock assessment of Hilsa Tenualosa ilisha using digital image measured length-frequency data”

The annual global average catch shares of the anadromous Hilsa, Tenualosa ilisha of Bangladesh increased rapidly from 74.5% all through 1984–2013 to 86.7% during the 2010–2015 periods. With a few exceptions, an increasing trend of Hilsa production over the last three decades was found in Bangladesh. Initially three options incorporating digital image measurements were compared to determine the best method for obtaining accurate length data. The length-frequency data measured from digital images showed that Hilsa have a moderate growth rate (K = 0.90 year−1) of up to 58.70 cm (L∞) TL. High fishing mortality (F = 2.83 year−1) and exploitation level (E = 0.67) suggest a slight overexploitation of the Hilsa fishery; the maximum sustainable yield (MSY) was estimated at 526,000 metric tons/year if therecommended TL at first capture (Lc) of 27 cm is adhered to. The present annual Hilsa catch is about 496,417 metric tons, which indicates the potential benefit of achieving MSY through sustainable fisheries management by regulating mesh size of nets and protecting brood fish. Size distribution of Hilsa within sanctuaries revealed a remarkable presence of juvenile fish during February–March in some areas, which suggests a need to readjust the fishing ban period from March–April to February–March. More fisheries management is necessary to reduce the exploitation level of Hilsa by 17% and at the same time increase the allowable Lc to potentially increase the MSY and CPUE

Reimagining large-scale open-water fisheries governance through adaptive comanagement in hilsa shad sanctuaries

Almost a half million fishers in Bangladesh are predominantly reliant on the hilsa shad (Tenualosa ilisha) fishery in the Meghna River and estuarine ecosystem. This paper adopts a broadened concept of social-ecological traps to frame the complex dynamics that emerge from social and ecological interactions in this highly natural resource-dependent social-ecological system (SES). We analyze how endogenous self-reinforcing processes in the system and poor initial conditions, particularly debt and lack of livelihood options outside fisheries, keep fishing households in poverty. We identify a policy decision in favor of incentive-based fisheries management as a critical juncture that influenced a trajectory of recovery in hilsa shad stocks in this complex adaptive system. Normative assessment of stakeholder perceptions indicates that fishers perceive a nominal improvement in well-being as a result of this policy. Compensation in return for compliance with a seasonal fishing ban in sanctuary areas does not, however, disrupt trap dynamics perpetuating the cycle of poverty, social exclusion, and political disempowerment in which fishing households are entrenched. Poverty and lack of alternative livelihood opportunities remain significant reasons for noncompliance with the ban as long as fishers do not have any meaningful representation in resource management and decision making. A secured tenure system through adaptive comanagement involving fishers in monitoring and enforcement of compliance with fishing bans, supported by sustainable finance for livelihood improvements outside of natural resource exploitation and predicated on responsive and accountable institutions for and by people who depend on the fishery, can form the foundation for local stewardship in a unique demonstration of contemporary large-scale open-water fisheries governance in this complex SES

Diagnosis of Malaria using Double Hidden Layer Extreme Learning Machine Algorithm with CNN Feature Extraction and Parasite Inflator

10.13039/501100003725-National Research Foundation of Korea-Grant Korean Government (Ministry of Science and ICT) (Grant Number: NRF-2020R1A2B5B02002478)Peer reviewedPublisher PD