19672 research outputs found
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The Anglerfish algorithm: a derivation of randomized incremental construction technique for solving the traveling salesman problem
No full textCombinatorial optimization focuses on arriving at a globally optimal solution given constraints, incomplete information and limited computational resources. The combination of possible solutions are rather vast and often overwhelms the limited computational power. Smart algorithms have been developed to address this issue. Each offers a more efficient way of traversing the search landscapes. Critics have called for a realignment in the bio-inspired metaheuristics field. We propose an algorithm that simplifies the search operation to only randomized population initialization following the Randomized Incremental Construction Technique, which essentially compartmentalizes optimization into smaller sub-units. This relieves the need of complex operators normally imposed on the current metaheuristics pool. The algorithm is more generic and adaptable to any optimization problems. Benchmarking is conducted using the traveling salesman problem. The results are comparable with the results of advanced metaheuristic algorithms. Hence, suggesting that arbitrary exploration is practicable as an operator to solve optimization problems. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature
Epithelial‐to‐mesenchymal transition (EMT) to sarcoma in recurrent lung adenosquamous carcinoma following adjuvant chemotherapy
No full textAdjuvant chemotherapy has long been indicated to extend survival in completely resected stage IB to IIIA non-small cell lung cancer (NSCLC). However, there is accumulating evidence that chemotherapy or chemoradiotherapy can induce epithelial-to-mesenchymal transition (EMT) in disseminated or circulating NSCLC cells. Here, we describe the first case of EMT as the cause of recurrence and metastasis in a patient with resected stage IIB lung adenosquamous carcinoma after adjuvant chemotherapy. We review the literature and explore the possible mechanisms by which EMT occurs in disseminated tumor cells (DTC) or circulating tumor cells (CTC) in response to adjuvant chemotherapy (cisplatin) as a stressor. We also explore the possible therapeutic strategies to reverse EMT in patients with recurrence. In summary, although adjuvant cisplatin-based chemotherapy in resected NSCLC does extend survival, it may lead to the adverse phenomenon of EMT in disseminated tumor cells (DTC) or circulating tumor cells (CTC) causing recurrence and metastasis. © 2019 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Lt
Travel motivation among cross border tourists: Case study of Langkawi
No full textResearch that focuses on regional tourists in Malaysia is scarce in literature. This study examined the influence of travel motivations; economic, nature, and cultural aspects on tourists’ loyalty intention in the context of Langkawi Island, Malaysia. A total of 200 fully answered questionnaires were collected from ASEAN tourists on the island using the purposive sampling technique, and the data were analyzed using the structural equation modeling technique. The results confirmed that the ‘economic aspect’ and ‘nature aspect’ are important motivational factors affecting tourists’ loyalty intention to revisit Langkawi. Although cultural aspect influences loyalty intention, its effect was weak. Managerial and marketing recommendations were made for tourism in Langkawi based on these findings. © 2019 Elsevier Lt
Electrical transportation mechanisms of molybdenum disulfide flakes-graphene quantum dots heterostructure embedded in polyvinylidene fluoride polymer
No full textIn the interest of the trend towards miniaturization of electronic gadgets, this study demonstrates a high-density data storage device with a very simple three-stacking layer consisting of only one charge trapping layer. A simple solution-processed technique has been used to fabricate the tristable non-volatile memory. The three-stacking layer was constructed in between two metals to form a two-terminal metal-insulator-metal structure. The fabricated device showed a large multilevel memory hysteresis window with a measured ON/OFF current ratio of 10 7 that might be attributed to the high charge trapped in molybdenum disulphide (MoS 2 ) flakes-graphene quantum dots (GQDs) heterostructure. Transmission electron microscopy was performed to examine the orientation of MoS 2 -GQD and mixture dispersion preparation method. The obtained electrical data was used further to speculate the possible transport mechanisms through the fabricated device by a curve fitting technique. Also, endurance cycle and retention tests were performed at room temperature to investigate the stability of the device. © 2019, The Author(s)
Gender difference in understanding ageing and retirement
No full textThe age-old wisdom is that “women live longer than men”. Gender difference in life expectancy is becoming a worldwide phenomenon both in developed and developing countries. The process of ageing may be viewed from the perspectives of physical, psychological, and social-economic wellbeing. We investigated gender difference in understanding ageing in relation to life expectancy, fears relating to diseases and deteriorating economic status, and perceived old age comfort and their preparedness. Data were obtained from an online survey and in-person interview of 518 respondents aged 40 years and older residing in Malaysia, which was based on a convenience sample collected from May 2015 to January 2016. Data were analysed using chi-squared tests and multinomial logistic regression. There were varying views between men and women when it came to understanding ageing in relation to life expectancy, fears of ageing, deteriorating economic status and their perception of old age comfort. Women were more optimistic about living longer compared to men but feared more the consequences of old age diseases. In spite of displaying less concern about financial preparedness, women were, however, willing to cut down expenses, while men would prefer longer working hours to ensure a comfortable retirement. © 2019, Faculty of Medicine, University of Malaya. All rights reserved
NSQM: A non-intrusive assessment of speech quality using normalized energies of the neurogram
No full textThis study proposes a new non-intrusive measure of speech quality, the neurogram speech quality measure (NSQM), based on the responses of a biologically-inspired computational model of the auditory system for listeners with normal hearing. The model simulates the responses of an auditory-nerve fiber with a characteristic frequency to a speech signal, and the population response of the model is represented by a neurogram (2D time-frequency representation). The responses of each characteristic frequency in the neurogram were decomposed into sub-bands using 1D discrete Wavelet transform. The normalized energy corresponding to each sub-band was used as an input to a support vector regression model to predict the quality score of the processed speech. The performance of the proposed non-intrusive measure was compared to the results from a range of intrusive and non-intrusive measures using three standard databases: the EXP1 and EXP3 of supplement 23 to the P series (P.Supp23) of ITU-T Recommendations and the NOIZEUS databases. The proposed NSQM achieved an overall better result over most of the existing metrics for the effects of compression codecs, additive and channel noises. © 201
Malignant Transformation of a Rosette-Forming Glioneuronal Tumor with IDH1 Mutation: A Case Report and Literature Review
No full textBackground: Rosette-forming glioneuronal tumor (World Health Organization grade I) is considered as a benign tumor with very low potential for progression. The potential for malignant transformation of this tumor is not known and has never been reported before in literature. Case Description: We report a 42-year-old man, diagnosed with rosette-forming glioneuronal tumor of the fourth ventricle with a positive isocitrate dehydrogenase 1 mutation, progressed to glioblastoma after 6 years from diagnosis. We discuss the clinical history, radiological findings, and histopathological characteristic with immunohistochemistry findings observed in this unique case. Conclusions: Despite being acceptable as benign, based on our observations in this case, there is a potential for malignant transformation of rosette-forming glioneuronal tumor. The role of isocitrate dehydrogenase 1 mutation leading to malignant transformation could not be established as our finding is novel and further prospective studies are required to prove this association. © 2019 The Author(s
The role of mass media in communicating climate science: An empirical evidence
No full textWorld leaders signed the Paris Agreement in 2015 to keep global temperatures well below 2 °C. This Paris Agreement will facilitate achieving Sustainable Development Goal-13 (Climate Action) by 2030. However, without collective action, it is quite impossible to achieve the terms of this agreement. In this regard, the mass media can contribute to making people aware of the subsequent effect of climate change at all levels. The mass media, as a source of information, might play a significant role in raising public awareness and understanding of climate sciences. This paper examines the influence of the mass media on awareness, attitudes and knowledge of climate change, which may lead to environmentally friendly behaviour. This paper employs structural equation modelling to examine the relationship among the studied variables. The results reveal that the mass media influences awareness, attitudes and knowledge of climate change. This study also finds mediating effects of awareness, attitudes and knowledge of climate change between the mass media and environmentally friendly behaviour. The results imply that the mass media contributes to creating awareness, enhancing understating and shaping favourable attitudes towards climate change. The findings could guide policymakers to take appropriate steps to promote a greater awareness of climate change using the mass media. © 201
Effect of Mobile Phase pH on the Electrospray Ionization Efficiency and Qualitative Analysis of Pharmaceuticals in ESI + LC-MS/MS
No full textThe effect of mobile phase pH on positive ionization process and retention time of nine pharmaceuticals on ultra-performance liquid chromatography-electrospray-tandem mass spectrometry (LC-MS/MS) was discussed. The effective use of high and low mobile phase pH in LC-MS/MS qualitative analyses method was also evaluated by comparing the instrument detection limit, quantification limit, precision, linearity and signal to noise (S/N) under low and high mobile phase pH. In this work, six mobile phase pH that ranged between pH 2 and pH 10 were used to evaluate the effect of the mobile phase pH changes on the ionization process in electrospray ionization. Results revealed that high mobile phase pH ionized more pharmaceuticals molecules and gave a higher signal than low mobile phase pH in positive ionization mode. The results proved that ammonium ion was better as a proton donor in high pH mobile phase than the hydronium ion in acidic mobile phase. The results revealed that the qualitative LC-MS/MS analyses method by using high mobile phase pH has better performance for most analytes in terms of sensitivity, precision, linearity and S/N than the low mobile phase pH. © 2019 The Author(s). Published by Oxford University Press. All rights reserved
Energy intensified integrated advanced oxidation technology for the treatment of recalcitrant industrial wastewater
No full textThis work aimed at providing additional information and knowledge on the possibility to overcome the limitation of conventional advanced oxidation processes (AOPs) through hybridization. In the present work, a number of photochemical and non-photochemical AOPs such as direct photolysis (UV), photolysis of hydrogen peroxide using UV light (UV/H2O2), UV assisted coagulation (UV– Fe2+ coagulation), Fenton process, Fe2+ coagulation and photo-Fenton process were compared to determine their feasibility to treat real textile wastewater. The Batik industry, which is a textile cottage industry in Malaysia has reported problems related to safe environmental disposal of its pollutants, mainly dyestuff. The comparison was made in terms of Chemical oxygen demand (COD), Total organic carbon (TOC) and colour removal together with electricity consumption. Among the processes evaluated, the highest COD removal was achieved for photo -Fenton oxidation (91.2%), followed by Fenton oxidation (81.4%), UV/H2O2 (68.0%), UV- Fe2+ coagulation (55.0%), Fe2+ coagulation (43.0%) and UV photolysis (10.0%). At the optimal operating conditions (room temperature, undiluted contaminants), the photo-Fenton hybrid process achieved complete decolourization and higher removal of COD (91.2%) and TOC (78.5%) with minimum electrical energy per order of 0.02 kWhr/m3 compared to other AOPs. About 13% reduction in the total chemical cost and 10% increase in the degradation were observed by combining the Fenton process with UV radiation compared to the conventional Fenton process. The GC/MS analysis revealed that the photo-Fenton process successfully removed 87% of organic compounds. The sludge characterization studies by Particle Size Distribution proved that the Fenton-generated sludge achieved quality suitable for disposal. Photo-Fenton is the cheapest option with highest removal (91%) as its required only 0.0021. Therefore, this study concluded that the photo-Fenton process was an economically viable and appropriate treatment method for enhancing biodegradability of recalcitrant contaminants