JPEG steganography: A performance evaluation of quantization tables

The two most important aspects of any image based steganographic system are the imperceptibility and the capacity of the stego image. This paper evaluates the performance and efficiency of using optimized quantization tables instead of default JPEG tables within JPEG steganography. We found that using optimized tables significantly improves the quality of stego-images. Moreover, we used this optimization strategy to generate a 16x16 quantization table to be used instead of that suggested. The quality of stego-images was greatly improved when these optimized tables were used. This led us to suggest a new hybrid steganographic method in order to increase the embedding capacity. This new method is based on both and Jpeg-Jsteg methods. In this method, for each 16x16 quantized DCT block, the least two significant bits (2-LSBs) of each middle frequency coefficient are modified to embed two secret bits. Additionally, the Jpeg-Jsteg embedding technique is used for the low frequency DCT coefficients without modifying the DC coefficient. Our experimental results show that the proposed approach can provide a higher information-hiding capacity than the other methods tested. Furthermore, the quality of the produced stego-images is better than that of other methods which use the default tables

High capacity steganographic method based upon JPEG

The two most important aspects of any image-based steganographic system are the quality of the stegoimage and the capacity of the cover image. This paper proposes a novel and high capacity steganographic approach based on Discrete Cosine Transformation (DCT) and JPEG compression. JPEG technique divides the input image into non-overlapping blocks of 8x8 pixels and uses the DCT transformation. However, our proposed method divides the cover image into nonoverlapping blocks of 16x16 pixels. For each quantized DCT block, the least two-significant bits (2-LSBs) of each middle frequency coefficient are modified to embed two secret bits. Our aim is to investigate the data hiding efficiency using larger blocks for JPEG compression. Our experiment result shows that the proposed approach can provide a higher information hiding capacity than Jpeg-Jsteg and Chang et al. methods based on the conventional blocks of 8x8 pixels. Furthermore, the produced stego-images are almost identical to the original cover images

Optimum design of composite prestressed concrete girder railway bridges

This paper deals with the formulation of design optimisation of pretsressed concrete bridges. The bridge is of a slab-on-girder type, hence modeled as an equivalent orthotropic plate. The whole bridge system is considered as a simply supported right angle plate. Following linear elastic behaviour, the governing fourth order differential equation of the plate for patch load is solved in order to find out load distribution on the girders forming the bridge as well as the deflections and internal forces at critical sections of the whole bridge. The optimisation problem is formulated for various cross sectional geometries including rectangular, symmetrical I, unsymmetrical I, box, T and inverted T sections. The design variables are the main cross sectional dimensions, prestressing force and tendon eccentricity. The objective function comprises the cost of concrete material, formwork and prestressing steel tendons. The constraint functions are set to satisfy design requirements as per British Standards for bridges (BS 5400). Nonlinear optimisation method based on sequential unconstrained minimisation technique (SUMT) is employed to achieve optimum bridge configuration for specific design parameters of span length, concrete compressive strength and railway loading patterns. A purpose built computer program is set up to carry out the solution of the design optimisation problem efficiently in terms of time and effort. A typical example of unsymmetrical I-section having a small bottom flange as compared to the top flange width with composite deck effect is presented. The results show that the total cost increases as the span increases due to the increase of the initial prestressing force. Furthermore, the total cost decreases as the concrete compressive strength increases in spite of the increasing of the prestressing force. This is due to decrease of the overall depth, top and bottom flange widths, hence leading to a smaller girder size. Such finding will encourage engineers to adopt high strength concrete for bridges as it will help reducing not only the initial cost but also the life cycle cost of the bridge over its entire life

Job Satisfaction of the Employees in the Mobile Phone Corporates in Bangladesh: A Case Study

Optimizing employee satisfaction is a key to the success of any business that relies on a variety of organizational and psycho-economic factors. This study was conducted to identify that sort of key factors, which are responsible to influence on the overall job satisfaction in the growing mobile phone corporate in Bangladesh. The phone corporates, which are included here in the study, are Grameen Phone (GP), Bangla Link and Aktel. The factors included in the investigation as independent variables are Compensation Package, Supervision, Career Growth, Training and Development, Working atmosphere, Company Loyalty and Performance Appraisal. The result indicates that training and performance appraisal, work atmosphere, compensation package, supervision, and company loyalty are the key factors that impact on employees’ job satisfaction in these corporations. The study also finds that the employees of these three corporations possessed above of the moderate level and positive attitude towards job satisfaction, which could be nudged up to excellent status of employee satisfaction if the management takes those identified factors with a little more rigorous weight into their considerations and acts further accordingly.

Fungal dysbiosis predicts the diagnosis of pediatric Crohn's disease

AIM: To investigate the accuracy of fungal dysbiosis in mucosa and stool for predicting the diagnosis of Crohn’s disease (CD). METHODS: Children were prospectively enrolled in two medical centers: one university hospital and one private gastroenterology clinic in the city of Riyadh, Kingdom of Saudi Arabia. The children with confirmed diagnosis of CD by standard guidelines were considered cases, and the others were considered non-inflammatory bowel disease controls. Mucosal and stool samples were sequenced utilizing Illumina MiSeq chemistry following the manufacturer’s protocols, and abundance and diversity of fungal taxa in mucosa and stool were analyzed. Sparse logistic regression was used to predict the diagnosis of CD. The accuracy of the classifier was tested by computing the receiver operating characteristic curves with 5-fold stratified cross-validation under 100 permutations of the training data partition and the mean area under the curve (AUC) was calculated. RESULTS: All the children were Saudi nationals. There were 15 children with CD and 20 controls. The mean age was 13.9 (range: 6.7-17.8) years for CD children and 13.9 (3.25-18.6) years for controls, and 10/15 (67%) of the CD and 13/20 (65%) of the control subjects were boys. CD locations at diagnosis were ileal (L1) in 4 and colonic (L3) in 11 children, while CD behavior was non-stricturing and non-penetrating (B1) in 12 and stricturing (B2) in 3 children. The mean AUC for the fungal dysbiosis classifier was significantly higher in stools (AUC = 0.85 ± 0.057) than in mucosa (AUC = 0.71 ± 0.067) (P < 0.001). Most fungal species were significantly more depleted in stools than mucosal samples, except for Saccharomyces cerevisiae and S. bayanus, which were significantly more abundant. Diversity was significantly more reduced in stools than in mucosa. CONCLUSION: We found high AUC of fungal dysbiosis in fecal samples of children with CD, suggesting high accuracy in predicting diagnosis of CD. Key Words: Fungiome, Mycobiome, Crohn’s disease, Inflammation, Saudi children Core tip: We found high accuracy of fungal dysbiosis in predicting diagnosis of Crohn’s disease (CD), a finding similar to bacterial dysbiosis. However, the higher area under the curve for the fungal dysbiosis classifier in stool (0.85 ± 0.057) than in mucosa (0.71 ± 0.067) (P < 0.001), contrasts with bacterial studies, suggesting higher accuracy of stool samples. Although the clinical application of this finding is limited at present by the high cost of fungal analysis, such information is important from a scientific viewpoint, to increase the understanding of the role of fungal flora in CD and to stimulate further studies.The authors extend their appreciations to the Deanship of Scientific Research at King Saud University in Riyadh, Kingdom of Saudi Arabia for funding this work through Research Group No [RGP-1436-007]. This work was also supported by a grant from the Simons Foundation [No. 409704] to Kirill Korolev) and by the startup fund from Boston University to Kirill Korolev. Simulations were carried out on Shared Computing Cluster at Boston University. Rajita Menon was partially supported by a Hariri Graduate Fellowship from Boston University. Harland Winter, MD received support from Martin Schlaff and the Diane and Dorothy Brooks Foundation. (RGP-1436-007 - King Saud University in Riyadh, Kingdom of Saudi Arabia; 409704 - Simons Foundation; Boston University; Hariri Graduate Fellowship from Boston University; Diane and Dorothy Brooks Foundation)Published versio

The impact of Organizational Citizenship Behavior on Job Performance at Greater Amman Municipality

This study aims to investigate the effect of organizational citizenship behavior, henceforth (OCB) on Job Performance in Amman Greater Municipality. One hundred and fifty responses have been collected  by means of questionnaire. Statistical analysis  techniques such as descriptive statistics and correlation, multiple regressions, are  employed. To confirm the suitability of data collection instrument, a Skewnes Coefficient test and Cronbach’s Alpha are used. The findings of this  study  supported the hypotheses that (OCB) positively impacts (JP) of Amman Greater Municipality. The  OCB factors have an  impact on job performance. This means that the perception of employees toward OCB has a positive and significant influence on employees performance. The  OCB factors have an impact on work volume ,on work quality ,employee-colleagues relationship as a dependent variable and on employee-higher level relationships. This study provides suitable recommendations on the scope for improvement based on current levels of various specific impact organizational citizenship behavior and its dimensions. Also the study provides suitable recommendations on the scope of improvement based on current levels of various predominant organizational citizenship behavior criteria that directly impact Job Performance of  Amman Greater Municipality. Key Words: Organizational citizenship behavior, Job Performance, Amman Greater Municipality

The Reliability and Validity of a MLCT-Scale for the Assessment of Kindergarten Children

This study was derived from the review of literature on motivation to learn, and creative thinking, in kindergarten children. While both these themes are explored reasonably in depth, there is very little research on motivation to learn creative thinking, which is a pillar of educational development. The researcher found the reason was that there was no Scale to measure this aspect, and so he constructed a new Motivation to Learn Creative Thinking Scale (MLCT-Scale) among kindergarten children. He also investigated the psychometric characteristics of the Scale. This Scale construction and investigation findings are reported here. The methodology used in this study was Descriptive survey. In all, 21 items formed the MLCT- scale within 5 dimensions. It uses a 5-points Likert Scale. Before conducting the Study, the two validities of the scale, concept and concurrent validities, were assessed. The study sample size was a random selection of 360 Kindergarten children, restricted to Amman city in Jordan. As this was a new Scale, the researcher took utmost care, through a series of statistical tests, to ensure Reliability, Concept validity and Construct validity of the Scale. He also ensured that the factor loading of each of the 21 items onto 5 factors was very strong. The study findings showed high coefficient correlations for Reliability, Concept and Concurrent Validity. There was a strong loading of the 5 scale dimensions as shown by Exploratory Factor Analysis. It is strongly recommended by the researcher that motivation to learn creative learning in kindergarten can be assessed by implementing the Motivating Children to Learn Creative Thinking Scale

A new splitting-based displacement prediction approach for location-based services

In location-based services (LBSs), the service is provided based on the users' locations through location determination and mobility realization. Several location prediction models have been proposed to enhance and increase the relevance of the information retrieved by users of mobile information systems, but none of them studied the relationship between accuracy rate of prediction and the performance of the model in terms of consuming resources and constraints of mobile devices. Most of the current location prediction research is focused on generalized location models, where the geographic extent is divided into regular-shape cells. These models are not suitable for certain LBSs where the objectives are to compute and present on-road services. One such technique is the Prediction Location Model (PLM), which deals with inner cell structure. The PLM technique suffers from memory usage and poor accuracy. The main goal of this paper is to propose a new path prediction technique for Location-Based Services. The new approach is competitive and more efficient compared to PLM regarding measurements such as accuracy rate of location prediction and memory usage