17,916 research outputs found
Masalah-masalah dalam Kelulusan Merancang Pembangunan Perumahan
Praktis perancangan pembangunan tidak memberikan kuasa kepada pihak berkuasa tempatan menyediakan pelan pembangunan. Perancangan dan kawalan pembangunan terletak di bawah bidang kuasa Majlis Perancangan Negeri. Pertumbuhan pesat dalam sektor perumahan menunjukkan petanda positif terhadap pertumbuhan bandar di Sarawak. Kajian ini mendapati bahawa proses pemusatan yang dilakukan adalah adil kepada semua pihak bagi memastikan keseimbangan di semua bahagian. Selain itu, terdapat juga kekeliruan peranan dimainkan oleh pihak-pihak terlibat. Hasil kajian juga turut mengenalpasti beberapa masalah yang kerap berlaku, antaranya prosedur yang rumit, proses mendapat kelulusan lambat, birokrasi, serta risiko dalam perancangan dan pasaran. Walau bagaimanapun, amalan perancangan pembangunan mementingkan aspek kualiti dan kuantiti agar tidak membebankan pembeli. Kerajaan negeri melalui Majlis Perancangan Negeri mengawal harga perumahan bagi memastikan keseimbangan dan mengelak daripada berlakunya projek perumahan terbengkalai
Characterisation of a phantom for multiwavelength quantitative photoacoustic imaging
Quantitative photoacoustic imaging (qPAI) has the potential to provide high- resolution in vivo images of chromophore concentration, which may be indicative of tissue function and pathology. Many strategies have been proposed recently for extracting quantitative information, but many have not been experimentally verified. Experimental phantom-based validation studies can be used to test the robustness and accuracy of such algorithms in order to ensure reliable in vivo application is possible. The phantoms used in such studies must have well-characterised optical and acoustic properties similar to tissue, and be versatile and stable. Polyvinyl chloride plastisol (PVCP) has been suggested as a phantom for quality control and system evaluation. By characterising its multiwavelength optical properties, broadband acoustic properties and thermoelastic behaviour, this paper examines its potential as a phantom for qPAI studies too. PVCP's acoustic properties were assessed for various formulations, as well as its intrinsic optical absorption, and scattering with added TiO2, over a range of wavelengths from 400-2000 nm. To change the absorption coefficient, pigment-based chromophores that are stable during the phantom fabrication process, were used. These yielded unique spectra analogous to tissue chromophores and linear with concentration. At the high peak powers typically used in photoacoustic imaging, nonlinear optical absorption was observed. The Grüneisen parameter was measured to be   =  1.01  ±  0.05, larger than typically found in tissue, though useful for increased PA signal. Single and multiwavelength 3D PA imaging of various fabricated PVCP phantoms were demonstrated
Measurement of the temperature-dependent speed of sound and change in Gruneisen parameter of tissue-mimicking materials
Knowledge of the temperature dependence of the material properties of tissue-mimicking materials is useful or essential for many applications. This includes photoacoustic thermometry where the temperature dependence of the Grüneisen parameter of tissues leads to changes in the recorded photoacoustic signal amplitude with temperature. Here, a setup is described that can measure the temperature dependence of the speed of sound and photoacoustic conversion efficiency (μ a Γ) of tissue-mimicking materials. Agar-based phantoms, copolymer-in-oil, gel wax, PVCP, silicone and water were characterised in the newly developed setup for temperatures between 22°C and 50°C. This information provides a valuable resource for material characterisation and future development of tissue-mimicking materials
Dictionary Learning and Sparse Coding-based Denoising for High-Resolution Task Functional Connectivity MRI Analysis
We propose a novel denoising framework for task functional Magnetic Resonance
Imaging (tfMRI) data to delineate the high-resolution spatial pattern of the
brain functional connectivity via dictionary learning and sparse coding (DLSC).
In order to address the limitations of the unsupervised DLSC-based fMRI
studies, we utilize the prior knowledge of task paradigm in the learning step
to train a data-driven dictionary and to model the sparse representation. We
apply the proposed DLSC-based method to Human Connectome Project (HCP) motor
tfMRI dataset. Studies on the functional connectivity of cerebrocerebellar
circuits in somatomotor networks show that the DLSC-based denoising framework
can significantly improve the prominent connectivity patterns, in comparison to
the temporal non-local means (tNLM)-based denoising method as well as the case
without denoising, which is consistent and neuroscientifically meaningful
within motor area. The promising results show that the proposed method can
provide an important foundation for the high-resolution functional connectivity
analysis, and provide a better approach for fMRI preprocessing.Comment: 8 pages, 3 figures, MLMI201
Test materials for characterising heating from HIFU devices using photoacoustic thermometry
High intensity focused ultrasound (HIFU) is a non-invasive thermal therapy during which a focused ultrasound beam is used to destroy cells within a confined volume of tissue. Due to its increased use and advancements in treatment delivery, various numerical models are being developed for use in treatment planning software. In order to validate these models, as well as to perform routine quality checks and transducer characterisation, a temperature monitoring technique capable of accurately mapping the temperature rise induced is necessary. Photoacoustic thermometry is a rapidly emerging technique for non-invasive temperature monitoring, where the temperature dependence of the Gruneisen parameter leads to changes in the recorded photoacoustic signal amplitude with temperature. In order to use this technique to assess heating induced by HIFU in a metrology setting, a suitable test material must first be selected that exhibits an increase in the generated photoacoustic signal with temperature. In this study, the temperature dependence of the photoacoustic conversion efficiency (μaΓ) of several tissue-mimicking materials was measured for temperatures between 22 °C and 50 °C. Materials included were agar-based phantoms, copolymer-in-oil, gel wax, PVA cryogels, PVCP and silicone. This information provided a basis for the development of a volumetric phantom, which was sonicated in a proof-of-concept integrated photoacoustic thermometry system for monitoring of HIFU-induced heating. The results show the suitability of agar-based phantoms and photoacoustic thermometry to image the 3D heat distribution generated by a HIFU transducer
Predicting sustainable arsenic mitigation using machine learning techniques.
This study evaluates state-of-the-art machine learning models in predicting the most sustainable arsenic mitigation preference. A Gaussian distribution-based Naïve Bayes (NB) classifier scored the highest Area Under the Curve (AUC) of the Receiver Operating Characteristic curve (0.82), followed by Nu Support Vector Classification (0.80), and K-Neighbors (0.79). Ensemble classifiers scored higher than 70% AUC, with Random Forest being the top performer (0.77), and Decision Tree model ranked fourth with an AUC of 0.77. The multilayer perceptron model also achieved high performance (AUC=0.75). Most linear classifiers underperformed, with the Ridge classifier at the top (AUC=0.73) and perceptron at the bottom (AUC=0.57). A Bernoulli distribution-based Naïve Bayes classifier was the poorest model (AUC=0.50). The Gaussian NB was also the most robust ML model with the slightest variation of Kappa score on training (0.58) and test data (0.64). The results suggest that nonlinear or ensemble classifiers could more accurately understand the complex relationships of socio-environmental data and help develop accurate and robust prediction models of sustainable arsenic mitigation. Furthermore, Gaussian NB is the best option when data is scarce
A comparative study of hiv/aids knowledge and attitudes of hearing-impaired and non-hearing-impaired secondary school students in Ibadan
The study showed that the hearing-impaired students had poorer knowledge and attitudes to HIV/AIDS compared with their non-hearing-impaired counterparts. There is a pressing need for developmentA cross-sectional survey of all the hearing impaired students and an equal number of nonhearing-impaired students enrolled in a half way school in Ibadan was conducted. Four non-hearingimpaired students did not complete the survey and their responses were excluded from the finalanalysis. Data was analysed using the Statistical Package for the Social Sciences (version 11.0). Seventy-eight hearing-impaired and non 74 non-hearing impaired students completed the survey. Thirty (38.5%) hearing-impaired and 67 (90.5%) and non-hearing-impaired students knew that HIV could be transmitted via semen, vaginal fluid and blood, (
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