134 research outputs found
Real Interference Alignment: Exploiting the Potential of Single Antenna Systems
In this paper, the available spatial Degrees-Of-Freedoms (DOF) in single
antenna systems is exploited. A new coding scheme is proposed in which several
data streams having fractional multiplexing gains are sent by transmitters and
interfering streams are aligned at receivers. Viewed as a field over rational
numbers, a received signal has infinite fractional DOFs, allowing simultaneous
interference alignment of any finite number of signals at any finite number of
receivers. The coding scheme is backed up by a recent result in the field of
Diophantine approximation, which states that the convergence part of the
Khintchine-Groshev theorem holds for points on non-degenerate manifolds. The
proposed coding scheme is proved to be optimal for three communication
channels, namely the Gaussian Interference Channel (GIC), the uplink channel in
cellular systems, and the channel. It is proved that the total DOF of the
-user GIC is almost surely, i.e. each user enjoys half of its
maximum DOF. Having cells and users within each cell in a cellular
system, the total DOF of the uplink channel is proved to be .
Finally, the total DOF of the channel with transmitters and
receivers is shown to be .Comment: Submitted to IEEE Transaction on Information Theory. The first
version was uploaded on arxiv on 17 Aug 2009 with the following title:
Forming Pseudo-MIMO by Embedding Infinite Rational Dimensions Along a Single
Real Line: Removing Barriers in Achieving the DOFs of Single Antenna System
The User-Education Programs in the University Libraries of Khyber Pakhtunkhwa: A Quantitative Study
This study evaluated the User Education Programs (UEPs) in the Public Sector Universitiesā libraries of Khyber Pakhtunkhwa. This study aimed to explore the overall scenario of the userās education, to probe how much time is allotted for UEPs, what methods and approaches of UEPs are in practice and to suggest the measures for improving user education programs in the libraries. The data from the target sample was collected through questionnaire which was then analyzed as per the objectives of the study. The study identified 34 central and departmental libraries in the six universities of the Southern Part of the province of Khyber Pakhtunkhwa. All the universitiesā central and departmental libraries offered users education programs to their users. The UEPs were conducted by the library staff and the faculty members of the respective departments. The most adopted methods or approaches for user education programs were lecture library tours and demonstration. Most of the respondents suggested that there should be a written policy for UEPs, the instruction sessions should be conducted on regular basis, and the UEPs should be organized at the departmental level
The Epidemiological Aspects of Tuberculosis in Hamadan Province during 2005ā11
Background: Epidemiological information on tuberculosis (TB) is required to plan control and prevention strategies
and to inform service delivery systems. The aim of present study was to determine the epidemiological status of TB in
Hamadan Province covering a seven-year period.
Methods: In this cross-sectional study all registered TB patients suffering from any form of smear-positive, smearnegative
or extra pulmonary from 2005 to 2011 were assessed. Age-adjusted incidence trend was studied. The CochranArmitage
(C-A) test was used for testing the trends over time.
Results: The mean age of TB patients was 57.0 (Ā±21.1), 49.9% were males, 52.8% were aged 61 years or older and 39.7%
were rural residents. Previous history of jailed was present in 13 (2.2%) patients and 12 (2.0%) were HIV positive. From
all TB patients, 60.8% were smear-positive, 87.6% were new cases, and 87.3% of smear-positive patients were cured
cases. Also, 23.6% patients had history of hospitalization for TB. More than half (55.4%) of TB patients were reported by
public health system. Age-adjusted incidence rates of all TB cases during 2005ā11 was 3.4, 3.2, 3.6, 4.7, 3.3, 4.4 and 7.3
in 100,000 respectively (C-A trend test, P< 0.001).
Conclusion: Although, the incidence rate of TB in Hamadan Province is lower than countryās average, increasing trend
of TB incidence is not concordant with its decreasing trend in Iran. An epidemiological study is required to evaluate risk
factors associated with TB to identify ways to decrease the prevalence of TB
Drug-related Atrioventricular Block: Is It a Benign Condition?
Introduction: Prognosis of the patients with beta blocker or calcium channel blocker induced AV block is not well known to date.Methods: All patients with symptomatic second-degree or third-degree atrioventricular block (AV) referred to our institution during one year were recuited prospectively and classified in two groups based on drug consumption (beta blocker/calcium channel blocker versus none). They were followed for six months and then collected data was analyzed.Results: The study included 49 patients, 28 patients (age 60.1 Ā± 20, 19 male) did not use any beta blocker or calcium channel blocker (No- DU group) and other 21 patients (age 73.5 Ā± 10.4, 7 male) receivd beta blocker, calcium channel blocker or both at the time of AV block (DU group). No-DU group was significantly younger than DU group. The most common atrial rhythm in both groups was sinus. There was no significant difference in QRS wideness or ventricular rate. AV block regressed in 43% of the DU group after discontinuation of drug for five half-life, but, Mobitz type 2 or complete AV block occurred again during six months in 50% of them without Ā consumption of the culprit drug.Conclusions: More than two third of the patients who developed AV block on beta blocker and/or calcium channel blocker needed permanent pacemaker in six months of follow- up, so we concluded that the development of AV block was not as benign as it seems in these patients
Utilizing social virtual reality robot (V2R) for music education to children with high-functioning autism
Virtual Reality (VR) technology is a growing technology that has been used in various fields of psychology, education, and therapy. One group of potential users of VR are children with autism who need education and have poor social interactions; this technology could help them improve their social skills through real-world simulation. In this study, we evaluated the feasibility of conducting virtual music education programs with automatic assessment system for children with autism at treatment/research centers without the need to purchase a robot, resulting in the possibility of offering schedules on a larger scale and at a lower cost. Intervention sessions were conducted for five children with high-functioning autism ranging in age from 6 to 8 years old during 20 weeks which includes a baseline session, a pre-test, training sessions, a post-test, and a follow-up test. Each music education sessions involved teaching different notes and pieces of music according to the childās cooperation, accuracy, and skill level utilizing virtual reality robots and virtual musical instruments. Actually, by analysis of psychological tests, and questionnaires conducted by a psychologist, we observe slight improvements in cognitive skills because of the ceiling effect. Nevertheless, the effectiveness of the proposed method was proved by conducting statistical analysis on the childās performance data during the music education sessions which were obtained by using both video coding and the proposed automatic assessment system. Consequently, a general upward trend in the musical ability of participants was shown to occur in these sessions, which warrants future studies in this field
A fault-tolerant cascaded switched-capacitor multilevel inverter for domestic applications in smart grids
Cascaded multilevel inverters (MLIs) generate an output voltage using series-connected power modules that employ standard configurations of low-voltage components. Each module may employ one or more switched capacitors to double or quadruple its input voltage. The higher number of switched capacitors and semiconductor switches in MLIs compared to conventional two-level inverters has led to concerns about overall system reliability. A fault-tolerant design can mitigate this reliability issue. If one part of the system fails, the MLI can continue its planned operation at a reduced level rather than the entire system failing, which makes the fault tolerance of the MLI particularly important. In this paper, a novel fault location technique is presented that leads to a significant reduction in fault location detection time based on the reliability priority of the components of the proposed fault-tolerant switched capacitor cascaded MLI (CSCMLI). The main contribution of this paper is to reduce the number of MLI switches under fault conditions while operating at lower levels. The fault-tolerant inverter requires fewer switches at higher reliability, and the comparison with similar MLIs shows a faster dynamic response of fault detection and reduced fault location detection time. The experimental results confirm the effectiveness of the presented methods applied in the CSCMLI. Also, all experimental data including processor code, schematic, PCB, and video of CSCMLI operation are attached. Ā© 2013 IEEE
Designing EthAKUL: A mobile just-in-time learning environment for bioethics in Pakistan
In developing countries such as Pakistan, bioethics has not been included in mainstream thinking in medical education. The authorsā experiences suggest that current methods of teaching bioethics are problematic as students are unable to translate theory to practice. Alternative pedagogies, such as just-in-time learning (JiTL) using mobile devices, may be able to foster the development and implementation of ethical reasoning among nurses, doctors, and medical and nursing students. This research was conceived to determine the effectiveness of mobile JiTL ā anytime, anyplace learning through mobile devices ā for teaching bioethics. After obtaining ethical clearance, a participatory design (PD) approach was adopted to ensure input from all stakeholders for the design of āEthAKULā, comprising a mobile app, five modules and just-in-time pedagogy. The name of the app is an acronym evoking ethics, learning and the university where the project originated. As a part of the design process, three PD workshops were held with junior doctors, nurses, nursing students, medical students and bioethics teaching faculty, and five meetings were held with faculty members, to discuss functional specifications and user-acceptance testing of the app. The feedback related to the nature of common ethical issues encountered in clinical settings, the existing process of teaching and learning bioethics, and the requested features of the app were recorded. These data sets were analyzed and synthesized into functional and technical specifications for the mobile app. The software programmers developed the app with the close involvement of the stakeholders. The development of teaching content continued alongside this process. While this enabled EthAKULās developers to incorporate needs of all stakeholders, challenges were encountered in the process relating to the pragmatic and conceptual aspects of JiTL, ML and PD. We discuss the implications of this research in bringing about transformative changes in higher education
Variation of Biophysical Parameters of the Skin with Age, Gender, and Body Region
Background. Understanding the physiological, chemical, and biophysical characteristics of the skin helps us to arrange a proper approach to the management of skin diseases. Objective. The aim of this study was to measure 6 biophysical characteristics of normal skin (sebum content, hydration, transepidermal water loss (TEWL), erythema index, melanin index, and elasticity) in a normal population and assess the effect of sex, age, and body location on them. Methods. Fifty healthy volunteers in 5 age groups (5 males and females in each) were enrolled in this study. A multifunctional skin physiology monitor (Courage & Khazaka electronic GmbH, Germany) was used to measure skin sebum content, hydration, TEWL, erythema index, melanin index, and elasticity in 8 different locations of the body. Results. There were significant differences between the hydration, melanin index, and elasticity of different age groups. Regarding the locations, forehead had the highest melanin index, where as palm had the lowest value. The mean values of erythema index and melanin index and TEWL were significantly higher in males and anatomic location was a significant independent factor for all of 6 measured parameters. Conclusion. Several biophysical properties of the skin vary among different gender, age groups, and body locations
The epidemiological aspects of tuberculosis in Hamadan Province during 2005ā11
Background:
Epidemiological information on tuberculosis (TB) is required to plan control and prevention strategies
and to inform service delivery systems. The aim of present study was to determine the epidemiological status of TB in
Hamadan Province covering a seven-year period.
Methods:
In this cross-sectional study all registered TB patients suffering from any form of smear-positive, smear-
negative or extra pulmonary from 2005 to 2011 were assessed. Age-adjusted incidence trend was studied. The Cochran-
Armitage (C-A) test was used for testing the trends over time.
Results:
The mean age of TB patients was 57.0 (Ā±21.1), 49.9% were males, 52.8% were aged 61 years or older and 39.7%
were rural residents. Previous history of jailed was present in 13 (2.2%) patients and 12 (2.0%) were HIV positive. From
all TB patients, 60.8% were smear-positive, 87.6% were new cases, and 87.3% of smear-positive patients were cured
cases. Also, 23.6% patients had history of hospitalization for TB. More than half (55.4%) of TB patients were reported by
public health system. Age-adjusted incidence rates of all TB cases during 2005ā11 was 3.4, 3.2, 3.6, 4.7, 3.3, 4.4 and 7.3
in 100,000 respectively (C-A trend test,
P
< 0.001).
Conclusion:
Although, the incidence rate of TB in Hamadan Province is lower than countryās average, increasing trend
of TB incidence is not concordant with its decreasing trend in Iran. An epidemiological study is required to evaluate risk
factors associated with TB to identify ways to decrease the prevalence of TB
- ā¦