Analysis of Customer Satisfaction: Bank of Bhutan Limited

Druk Holding and Investments (DHI) that holds and manages twenty State Owned Enterprises (SOEs) in Bhutan assesses customer satisfaction annually for five service oriented companies through the independent survey to measure customer service related performances of the companies. This paper uses the data collected by the consulting team in 2013 that covers twenty districts of Bhutan. The team collected the data using structured questionnaire covering different aspects of customer satisfaction. Data was collected from 2123 respondents representing various demographic characters. Besides looking into the descriptive aspects of the statistics, this paper analyses the relational between customer satisfaction level and gender, income groups and educational levels so that each group can be targeted with different strategies.  Findings suggest that all types of customers consider service reliability and value for money (price) as the most important factors that attributes to their satisfaction. It was found out that generally females are more satisfied than male respondents at the same level of service quality indicators. Study further establishes the inverse relationships between customer satisfaction level and income and with educational levels of the customers.

Comparison of super-resolution algorithms applied to retinal images

A critical challenge in biomedical imaging is to optimally balance the trade-off among image resolution, signal-to-noise ratio, and acquisition time. Acquiring a high-resolution image is possible; however, it is either expensive or time consuming or both. Resolution is also limited by the physical properties of the imaging device, such as the nature and size of the input source radiation and the optics of the device. Super-resolution (SR), which is an off-line approach for improving the resolution of an image, is free of these trade-offs. Several methodologies, such as interpolation, frequency domain, regularization, and learning-based approaches, have been developed over the past several years for SR of natural images. We review some of these methods and demonstrate the positive impact expected from SR of retinal images and investigate the performance of various SR techniques. We use a fundus image as an example for simulations

Image Restoration Methods for Retinal Images: Denoising and Interpolation

Retinal imaging provides an opportunity to detect pathological and natural age-related physiological changes in the interior of the eye. Diagnosis of retinal abnormality requires an image that is sharp, clear and free of noise and artifacts. However, to prevent tissue damage, retinal imaging instruments use low illumination radiation, hence, the signal-to-noise ratio (SNR) is reduced which means the total noise power is increased. Furthermore, noise is inherent in some imaging techniques. For example, in Optical Coherence Tomography (OCT) speckle noise is produced due to the coherence between the unwanted backscattered light. Improving OCT image quality by reducing speckle noise increases the accuracy of analyses and hence the diagnostic sensitivity. However, the challenge is to preserve image features while reducing speckle noise. There is a clear trade-off between image feature preservation and speckle noise reduction in OCT. Averaging multiple OCT images taken from a unique position provides a high SNR image, but it drastically increases the scanning time. In this thesis, we develop a multi-frame image denoising method for Spectral Domain OCT (SD-OCT) images extracted from a very close locations of a SD-OCT volume. The proposed denoising method was tested using two dictionaries: nonlinear (NL) and KSVD-based adaptive dictionary. The NL dictionary was constructed by adding phases, polynomial, exponential and boxcar functions to the conventional Discrete Cosine Transform (DCT) dictionary. The proposed denoising method denoises nearby frames of SD-OCT volume using a sparse representation method and combines them by selecting median intensity pixels from the denoised nearby frames. The result showed that both dictionaries reduced the speckle noise from the OCT images; however, the adaptive dictionary showed slightly better results at the cost of a higher computational complexity. The NL dictionary was also used for fundus and OCT image reconstruction. The performance of the NL dictionary was always better than that of other analytical-based dictionaries, such as DCT and Haar. The adaptive dictionary involves a lengthy dictionary learning process, and therefore cannot be used in real situations. We dealt this problem by utilizing a low-rank approximation. In this approach SD-OCT frames were divided into a group of noisy matrices that consist of non-local similar patches. A noise-free patch matrix was obtained from a noisy patch matrix utilizing a low-rank approximation. The noise-free patches from nearby frames were averaged to enhance the denoising. The denoised image obtained from the proposed approach was better than those obtained by several state-of-the-art methods. The proposed approach was extended to jointly denoise and interpolate SD-OCT image. The results show that joint denoising and interpolation method outperforms several existing state-of-the-art denoising methods plus bicubic interpolation.4 month

Statistical Analysis of Hartmann-Shack Images of a Pre-school Population

The impact of uncoordinated growth of the optical components of the eye may stimulate different levels of monochromatic aberrations in the growing eyes of the children. This thesis aimed to examine the impact of age, visual acuity and refractive error on higher order aberrations as well as to determine the relationship between them. Hartman Shack images taken with the Welch Allyn® SureSight Autorefractor were calibrated in order to determine the Zernike coefficients up to the 8th order for a pupil diameter of 5mm. The MATLAB code proposed by Thibos et al that follows the standard for reporting the optical aberrations of the eye was the basis of code written for this study. Modification was required to suit the specific needs of the Welch Allyn® SureSight Autorefractor. After calibration the lower order aberrations could then be compared with the results from cyclopledged retinoscopy. RMS values of aberrations and Strehl ratios were computed to examine the optical performance of the eye. A total of 834 Hartmann-Shack images of 436 children (mean age 3.94± 0.94 years, range 3 to 6 years) were examined in this study (right eyes 436; left eyes 398).The sample had a mean (± STD) spherical equivalent of 1.19 ± 0.59D, a mean with-the-rule astigmatism (J0) of 0.055 ± 0.22D, and a mean oblique astigmatism (J45) of 0.01±0.14D. Visual acuity varied from 6/6 to 6/18. Moderate mirror symmetry was found between the eyes. Like refractive error, higher order aberrations declined with age in this sample. There was an impact of higher order aberrations on refractive error. Significantly higher ocular aberrations were found in the higher hyperopic group (SE>+2.0D) compared to emmetropic (-0.5<SE<+0.5D) and low hyperopic groups (+0.5<SE<+2.0D). The Strehl ratio was significantly lower in the high hyperopic group. Higher Strehl ratios were observed for better acuity groups but the average Strehl ratios among the different visual acuity groups were not statistically significant. In conclusion, there was an impact of age on the ocular aberrations. A wider range of age from birth to adolescence is required for further investigation. This could be indirectly influenced by the age related changes in refractive error as the correlation between refractive error and the higher order aberrations were significant. This finding also concludes that Strehl Ratio alone is not capable of perfectly describing the visual acuity of the eye; other metrics such as the neural transfer function and neural noise are necessary to describe the resultant visual performance of the eye

Aversive reaction between disulfiram and betel quid among inpatients with alcohol use disorder in Bhutan: A preliminary study

Betel Quid (BQ) is commonly used in the Asia-Pacific region. Disulfiram is prescribed for people with alcohol use disorders (PwAUDs) after the completion of detoxification as an alternative to rehabilitation. This prospective observational study reports the aversive reactions and common symptoms of Disulfiram and BQ in PwAUDs. Participants included PwAUDs admitted to the psychiatric ward at the Jigme Dorji Wangchuck National Referral Hospital for detoxification, who were on Disulfiram and using BQ at the same time. Aversive reactions between Disulfiram and BQ were observed for 100 patients over a year. Twenty participants showed aversive reactions between BQ and Disulfiram. Common symptoms included sweating, diarrhea, dizziness, tremors, palpitations, shortness of breath, nausea and vomiting, and headache. Since PwAUDs in Bhutan are inducted on Disulfiram after detoxification, and most use BQ simultaneously, this study will help inform health care providers to educate people about the aversive reactions of Disulfiram and BQ

Psychiatric Morbidity in Psoriasis and Vitiligo in Two Tertiary Hospitals in Bangladesh

Background: Many of the established skin diseases give rise to psychiatric disorders notably psoriasis and vitiligo. In Bangladesh, no study has yet been reported on psychiatric morbidity among psoriasis and vitiligo patients. Objectives: The objective of the study was to see the psychiatric morbidities in two chronic skin diseases, psoriasis and vitiligo, in Bangladesh. Methods: This was a cross sectional, analytical and comparative study. It was conducted to see whether psychiatric morbidity was higher among patients with psoriasis than that of vitiligo. Specific types of psychiatric disorders were identified by consultant psychiatrist assigned as per criteria of (Diagnostic and Statistical Manual for Mental and Behavioural Disorders-Fourth Edition)DSM-IV among 50 patients with psoriasis and same number of patients with vitiligo and were compared. Study places were the Departments of Dermatology and Venereology, Bangabandhu Sheikh Mujib Medical University (BSMMU) and Dhaka Medical College Hospital (DMCH) in Dhaka city. Results: Among the two dermatological conditions, psychiatric disorders were found 25 (50%) in psoriatic patients and 12 (24%) that in vitiligo patients. The proportion of major depressive disorders (MDD) was higher among psoriasis patients 15(30.0%) compared to vitiligo patients 04(8.0%). However, no statistical difference was found between two groups of patients in terms of anxiety disorders (8% in psoriasis and 12% in vitiligo patients). In patients with psoriasis, MDD was found highest (30.0%) followed by anxiety disorders (8.0%), adjustment disorder (4.0%) and somatoform disorder not otherwise specified (2.0%). Whereas, among the vitiligo patients, anxiety disorder was found highest (12.0%) followed by MDD (8.0%). The Present study showed significant association of psychiatric morbidities in these two dermatological diseases (psoriasis and vitiligo) with the variables of the study population. Conclusion: It has been found in Bangladesh that the psychiatric morbidity is higher among the patients with psoriasis than vitiligo. Key words: Psoriasis; Vitiligo; Psychiatric morbidity DOI: http://dx.doi.org/10.3329/bsmmuj.v4i2.8636 BSMMU J 2011; 4(2):88-9