VECTOR MEASURES APPLIED TO OPTIMAL CONTROL FOR A CLASS OF EVOLUTION EQUATIONS ON BANACH SPACES

Ahmed, Nasir Uddin Korean Mathematical Society 2020 대한수학회논문집 Vol.35 No.4

In this paper we consider a class of nonlinear evolution equations on infinite dimensional Banach spaces driven by vector measures. We prove existence and uniqueness of solutions and continuous dependence of solutions on the control measures. Using these results we prove existence of optimal controls for Bolza problems. Based on this result we present necessary conditions of optimality.

Factors associated with intention to take COVID-19 vaccine among the university students in Bangladesh

Nasir Ahmed Shuvo,Md Sanaul Haque Mondal 대한백신학회 2022 Clinical and Experimental Vaccine Research Vol.11 No.3

Purpose: This study examined the Bangladeshi university students’ intention to take coronavirus disease 2019 (COVID-19) vaccines by assessing the Health Belief Model and Theory of Planned Behavior. Materials and Methods: University students were queried on their intention to take COVID-19 vaccines. The sample used in this study (n=310) was obtained through an online survey among university students (age, 18–25 years old) from August 7 to September 18, 2021. Results: Although over 90% of respondents showed their willingness to take the COVID-19 vaccine, around 37.3% of respondents still desired to wait and see to take the vaccine. The most frequently cited reasons for vaccines hesitancy were concerns over side effects (62.4%). There is still an unmet need for adequate information on COVID-19 vaccines (81.4%). Results of the binary logistic regression model showed that students from private universities (odds ratio [OR], 0.19; 95% confidence interval [CI], 0.04–0.97), respondents who concerned about the vaccine safety (OR, 0.07; 95% CI, 0.01–0.44) and side effects of vaccine (OR, 0.21; 95% CI, 0.05–0.89) were less willing to take COVID-19 vaccine. On the other hand, desire to wait to take COVID-19 vaccines was associated with marital status (OR, 7.76; 95% CI, 1.50–40.27); COVID-19 preventive behavior, including use of facemask (OR, 0.25; 95% CI, 0.09–0.70) and maintain social distance (OR,1.75; 95% CI, 1.00–3.07); COVID-19 infection (OR, 0.50; 95% CI, 0.26–0.99); provide more information on vaccines (OR, 2.32; 95% CI, 1.06–5.09); the perceived side effects (OR, 2.82; 95% CI, 1.54–5.17); and effectiveness of COVID-19 vaccines (OR, 2.41; 95% CI, 1.16–5.01). Conclusion: Public health managers should provide adequate information on COVID-19 vaccines to address the concerns about the safety and side effects of the vaccines.

Synthesis of Novel Quinoxalinone Derivatives by Conventional and Microwave Methods and Assessing their Biological Activity

Waqar Nasir,Munawar Ali Munawar,Ejaz Ahmed,Ahsan Sharif,Saeed Ahmed,Amjad Ayub,Misbahul Ain Khan,Faizul Hassan Nasim 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.10

In this study, twenty-one arylaminoquinoxalinone derivatives were synthesized and their antibacterial activities against Staphylococci aureus, Pseudomonas aureus, Escherichia coli, Bacillus subtilis, Salmonella typhi, and Shigella pneumoniae were evaluated relative to known antibiotics; augmentin, ampicillin, and chloramphenicol. The insecticidal activities of the prepared compounds were also investigated against Tribolium castaneum using permethrin as a standard insecticide. The derivatives were synthesized using both conventional and microwave techniques. Their structures were confirmed using spectral techniques and elemental analysis.

Indigenous Radiosynthesis of [131I]Iodobenzylguanidine ([131I]mIBG) for Neuroblastoma Imaging

Nadeem Ahmed Lodhi,Muhammad Irfan,Muhammad Nasir Saddique,Kahkshan Bashir Mir,Naseer Ahmed,Shazia Fatima,Mumtaz Khan,Muhammad Wasim,Samina Roohi 대한방사성의약품학회 2022 Journal of radiopharmaceuticals and molecular prob Vol.8 No.2

Indigenous diagnostic dose of 131I-labeled meta-iodobenzylguanidine ([131I]mIBG) was prepared via Cu+ catalyzed isotope exchange reaction generated in situ by sodium metabisulfite for imaging of neuroblastoma tumor. [131I]mIBG was produced in overall 85-90% radiochemical yield. The average amount of radioactivity of [131I]mIBG was 2164 MBq (1998-2331MBq) with an average specific activity > 1000 MBq/mg at the end of synthesis. The radiochemical purity was ≥ 99.9% after purification through Dowex-1 × 8 ion exchange resin (100-150 mesh) at the date of preparation. The stability of [131I]mIBG at concentration 480-555 MBq/mL was > 97% at 4 °C after 4 days. The room temperature (25 °C) stability of [131I]mIBG was > 98% after 24 h. Biodistribution of [131I]mIBG in patient showed uptake in salivary glands, liver, spleen and excreted though urinary bladder. Neuroendocrine medicated uptake into tumor lesion and metastatic sites were noted which strongly correlate with the morphological abnormalities of patient.

Plan Dose Evaluation of Three Dimensional Conformal Radiotherapy Planning (3D-CRT) of Nasopharyngeal Carcinoma (NPC): Experience of a Tertiary Care University Hospital in Pakistan

Abbasi, Ahmed Nadeem,Hafiz, Asim,Ali, Nasir,Khan, Khurshid Ahmed Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.10

Background: Radiation therapy is the mainstay of treatment for nasopharyngeal carcinoma. Importance of tumor coverage and challenges posed by its unique and critical location are well evident. Therefore we aimed to evaluate our radiation treatment plan through dose volume histograms (DVHs) to find planning target volume (PTV) dose coverage and factors affecting it. Materials and Methods: This retrospective study covered 45 histologically proven nasopharyngeal cancer patients who were treated with definitive 3D-CRT and chemotherapy between Feb 2006 to March 2013 at the Department of Oncology, Section Radiation Oncology, Aga Khan University Hospital, Karachi, Pakistan. DVH was evaluated to find numbers of shrinking field (phases), PTV volume in different phases and its coverage by the 95% isodose lines, along with influencing factors. Results: There were 36 males (80%) and 9 females (20%) in the age range of 12-84 years. Stage IVA (46.7%) was the most common stage followed by stage III (31.1). Eighty six point six-percent received induction, 95.5% received concurrent and 22.2% received adjuvant chemotherapy. The prescribed median radiation dose was 70Gy to primary, 60Gy to clinically positive neck nodes and 50Gy to clinically negative neck regions. Mean dose to spinal cord was 44.2Gy and to optic chiasma was 52Gy. Thirty seven point eight-percent patients completed their treatment in three phases while 62.2% required four to five phases. Mean volume for PTV3 was $247.8cm^3$ (50-644.3), PTV4 $173.8cm^3$ (26.5-345.1) and PTV5 $119.6cm^3$ (18.9-246.1) and PTV volume coverage by 95% isodose lines were 74.4%, 85.7% and 100% respectively. Advanced T stage, intracranial extension and tumor volume > $200cm^3$ were found to be important factors associated with decreased PTV coverage by 95% isodose line. Conclusions: 3D CRT results in adequate PTV dose coverage by 95% isodose line. However advanced T stage, intracranial extension and large target volume require more advanced techniques like IMRT for appropriate PTV coverage.

Evidence of spin-phonon coupling in La₂NiMnO₆ double perovskite

Nasir, Mohammad,Ahmed, Ateeq,Park, Hee Jung,Sen, Somaditya The Korea Association of Crystal Growth 2021 韓國結晶成長學會誌 Vol.31 No.3

Herein, a correlation between B-site cation order and spin-phonon coupling in La₂NiMnO₆ double perovskite has been investigated. Raman spectra of La₂NiMnO₆ double perovskite annealed at 950 and 1400℃ have been measured in the 140-598 K range. A substantial softening of the phonon modes has been observed below the Curie temperature, which emphasized the presence of the spin-phonon coupling in the system. The spin-phonon coupling was found to be stronger in relatively more ordered La₂NiMnO₆ double perovskite. Thus, the magnitude of spin-phonon coupling was influenced by the Ni/Mn cation order.

Novel Approach for Modeling Wireless Fading Channels Using a Finite State Markov Chain

Ahmed Abdul Salam,Ray Sheriff,Saleh Al-Araji,Kahtan Mezher,Qassim Nasir 한국전자통신연구원 2017 ETRI Journal Vol.39 No.5

Empirical modeling of wireless fading channels using common schemes such as autoregression and the finite state Markov chain (FSMC) is investigated. The conceptual background of both channel structures and the establishment of their mutual dependence in a confined manner are presented. The novel contribution lies in the proposal of a new approach for deriving the state transition probabilities borrowed from economic disciplines, which has not been studied so far with respect to the modeling of FSMC wireless fading channels. The proposed approach is based on equal portioning of the received signal-to-noise ratio, realized by using an alternative probability construction that was initially highlighted by Tauchen. The associated statistical procedure shows that a first-order FSMC with a limited number of channel states can satisfactorily approximate fading. The computational overheads of the proposed technique are analyzed and proven to be less demanding compared to the conventional FSMC approach based on the level crossing rate. Simulations confirm the analytical results and promising performance of the new channel model based on the Tauchen approach without extra complexity costs.

Adaptive threshold and optimal frame duration for multi-taper spectrum sensing in cognitive radio

Ahmed O. Abdul Salam,Ray E. Sheriff,Saleh R. Al-Araji,Kahtan Mezher,Qassim Nasir 한국통신학회 2019 ICT Express Vol.5 No.1

This paper delivers an accurate approximation for adaptive threshold and optimal frame detection algorithms based on the robust multi-taper method aiming at an efficient spectrum sensing in cognitive radio systems. An appropriate adaptive thresholding allows for seamless vacation of unlicensed secondary users from certain bands upon primary users’ requests, while arbitrary optimal frame detection contributes to the computational and throughput demands. Simulation exercises corroborate the given analysis over Rayleigh channel and multiple-input multiple-output configuration and emphasize the critical role of adopting applicable adaptive threshold and optimal frame detection policies.

Analgesic and antidiarrhoeal activities of Treama orientalis Linn. in mice

Sarder Nasir Uddin,Khan Mohammad Ahsan Uddin,Firoz Ahmed 경희대학교 융합한의과학연구소 2008 Oriental Pharmacy and Experimental Medicine Vol.8 No.2

Trema orientalis Linn. is commonly grown in many parts of Bangladesh. Its leaves have been used for analgesic and anti-diarrhoeal activity in traditional medicine. This study evaluates the potential analgesic and anti-diarrhoeal activity of methanol and aqueous extracts of leaves in experimental acetic acid induced writhing and castor oil induced diarrhoea in mice. The aqueous extract of leaves showed significant (P < 0.001) analgesic effect in acetic acid induced writhing in mice at a dose of 500 mg/kg body weight In castor oil induced antidiarrhoeal screening both extract increased latent period (P < 0.025) and decrease the number of stool (P < 0.025) at the dose of 500 mg/kg body weight comparable with that of the standard drug loperamide. The results provide a support for the use of this plant in traditional medicine and suggest its further investigation. Trema orientalis Linn. is commonly grown in many parts of Bangladesh. Its leaves have been used for analgesic and anti-diarrhoeal activity in traditional medicine. This study evaluates the potential analgesic and anti-diarrhoeal activity of methanol and aqueous extracts of leaves in experimental acetic acid induced writhing and castor oil induced diarrhoea in mice. The aqueous extract of leaves showed significant (P < 0.001) analgesic effect in acetic acid induced writhing in mice at a dose of 500 mg/kg body weight In castor oil induced antidiarrhoeal screening both extract increased latent period (P < 0.025) and decrease the number of stool (P < 0.025) at the dose of 500 mg/kg body weight comparable with that of the standard drug loperamide. The results provide a support for the use of this plant in traditional medicine and suggest its further investigation.

Modeling any Obstacle Shapes for Motion Planning of Circular Robots

Md Nasir Uddin Laskar,Seung Y. Choi,Ishtiaq Ahmed,TaeChoong Chung 제어로봇시스템학회 2013 제어로봇시스템학회 국제학술대회 논문집 Vol.2013 No.10

This paper presents an algorithm to model the workspace obstacles of a circular robot. An obstacle of any shape can be represented by line and circular arc segments. Based on robot radius, geometric representation is applied for both line and circular arcs and the operation is known as offsetting. Result of our algorithm creates an efficient configuration space and helps planning high-quality motion paths. Our method works differently for line and circular arc segments. Two major steps are: (i) finding the raw offset curve for both lines and circular arcs and (ii) removing the global invalid loops. The process takes O(n) times to find the raw offset curve and O((n + k) logm) times to remove global invalid loops, where n is the number of vertices in the original polygon, k is the number of self-intersections, and m is the number of segments in the raw offset curve and always m≤n. Local invalid loops are removed before generating the raw offset curve by invoking a pair-wise intersection detection test (PIDT). Our algorithm is very fast and computational complexity is approximately linear.