Archives- 

MIMO techniques increases the spectral efficiency of the transmission and increasing capacity by using Spatial Multiplexing and Precoding. MIMO Spatial Multiplexing is the simultaneous use of the same frequencies to transmit independent data streams. Precoding (mixing) of the two streams is used to optimize the transmission into the channel so that the receiver has the best chance of recovering the original data streams. Several nonlinear precoding methods including dirty paper coding is used to achieve the capacity region for MIMO. In this paper capacity of the MIMO system and sum rate comparison is analyzed by suggesting a modified precoding technique and a round robin user scheduling algorithm.

An innovative concept of International Mobile Telecommunications – Advanced (IMT-Advanced) which is specified by the International Telecommunications Union – Radio Communication Sector (ITU-R), aims to perform a peak data rate of up to 1 Gbps for low mobility and 100 Mbps for high mobility. A study item on Long Term Evolution (LTE)-Advanced has been commenced to meet the above need by the 3rd Generation Partnership Project (3GPP), that supports the transmission over a much wider bandwidth than the LTE systems. The techniques for efficient resource allocation for LTE-Advanced systems with aggregation of multiple Component Carriers (CC) are deeply analyzed in this paper. Bandwidth based resource allocation using carrier load balancing methods like Round-robin, Mobile Hashing and Walsh code methods, have been used and their performance analysis is done in terms of the throughput and coverage. It proposes a cross component carrier packet scheduling algorithm for an effective resource allocation among the users with aggregation of component carrier in comparison with the independent packet scheduling per CC. To study the multi carrier system, Long Term Evolution (LTE)-Advanced users and LTE Rel’8 users are selected. The various carrier load balancing methods are compared based on independent and cross CC packet scheduling and then coverage performance, cell throughput and user throughput are analyzed with the help of Full buffer and finite buffer transmission system.

Knowledge management is a process that helps organizations to find important information, select, organize and publish them; and it’s a proficiency that will be necessary for actions like solving problems, dynamic learning, decision making. Knowledge management can improve a wide range of organization performance properties by enabling company to more intelligent performance, but it’s not enough alone; because knowledge management to be useful needs undertaking staff to organization and their job, that accept the knowledge management process with spirit and heart and perform it (Wiig,1999:14). With considering the importance of this topic, the current discussion will study the relation between knowledge management and professional commitment of staff at a petroleum company in the south of Iran. Formation of this study was based on this question that with considering the importance of professional commitment and organizational commitment of staff, what the relation between knowledge management and professional commitment and organizational commitment of staff is. The tools of data collection in order to knowledge management evaluation is the 21 questions questionnaire of Proset et al., to evaluation of professional commitment and organizational commitment, that’s combination and native 27 questions questionnaire of Allen and Meyer et al.; the stability of professional commitment and organizational commitment obtained 83% and the stability of knowledge management evaluation was 0.87 and because of being Kronbakh alpha of questionnaires both more than 0.7, both questionnaires had obligatory stability. To determine being normal, the data obtained of Colmogroph-Smirnoph was applied and confirmed the results of being normal test. Hypothesizes of the study were examined by performing of Spearman correlation test and their significant and positive effects were proved, this means that knowledge management totally has a direct and significant relation with organizational commitment and professional commitment.

The objective of this research is to assess the adequacy of probability distribution for development of Rainfall IDF relationship at South-Eastern region of Bangladesh. Two common frequency analysis techniques Gumbel and Log Pearson Type III (LPTIII) distribution were used to develop the IDF relationship from rainfall data of this region. Yearly extreme rainfall data for last 41 years (1974-2014) from Bangladesh Meteorological Department (BMD) was used in this study. Indian Meteorological Department (IMD) empirical reduction formula was used to estimate the short duration rainfall intensity from yearly maximum rainfall data. The effects obtained using Gumbel method are slightly higher than LPT III distribution method. The chi-square goodness of fit test was used to determine the best fit probability distribution. The parameters of the IDF equations and coefficient of correlation for different return periods (2, 5, 10, 25, 50 and 100 years) were calculated by using nonlinear regression method. The results obtained offered that in all the cases the correlation coefficient is very high representing the goodness of fit of the formulae to estimate IDF curves in the region of interest. It was found that intensity of rainfall decreases with increase in rainfall duration. Further, a rainfall of any given duration will have a larger intensity if its return period is large. In other words, for a rainfall of given duration, rainfalls of higher intensity in that duration are rarer than rainfalls of smaller intensity.

This paper presents an optimum design technique of broadband two elements Yagi array antenna. The optimization parameter for the proposed antenna is the impedance bandwidth using appropriate dimensions of ground plane and in Yagi array, dipole is replace by patch, all element design in form patch. In this paper we observed effect with and without ground plane on impedance bandwidth. Appropriate Spacing is used between elements; all elements designed on scale of reflector, the proposed antenna can be used for C-Band application. For validation of proposed geometry IE3D Simulator is used.

The advent of wireless communications both inside and outside the home-office environment has led to an increased demand for effective encryption systems. The beauty of encryption technology comes out in more pronounced way when there is no absolute relation between cipher and original data and it is possible to rebuild the original image in much easier way. As chaotic systems are known to be more random and non-predictable, they can be made utilized in achieving the encryption. The transposition technology of encryption systems requires scrambleness behaviour in order to achieve the encryption of the data. This srambleness behaviour can be derived from the randomness property of chaos which can be better utilized in the techniques like transposition system. In wireless communication systems, bandwidth utilization is an important criterion. In order to use encryption system in wireless communication; key space plays an important role for the efficient utilization of the bandwidth. In this paper we present a chaos-based encryption algorithm for images. This algorithm is based on pixel scrambling where inthe randomness of the chaos is made utilized to scramble the position of the data. The position of the data is scrambled in the order of randomness of the elements obtained from the chaotic map and again rearranged back to their original position in decryption process.

With the rapid increase in number of women suffering from breast cancer, it’s early detection aids in fast and effective treatment. Mammography, which is currently the most popular method of breast screening has some limitation and microwave imaging offers an attractive alteration. Microwave imaging is attractive due to high contrast in dielectric properties between cancerous and non-cancerous tissue. The paper presents different type of feeding mechanism to the micro strip patch antenna used in microwave imaging and its comparison in an urge of getting an ultra-wide band of 3GHz within the frequency range of 3.2 GHz to 10.6 GHz. The antenna is Designed and simulated using Ansoft High Frequency Structure Simulator (HFSS)

The aim of this paper is to inspect the dares of female entrepreneurship in Lahore (n=150). Through a questionnaire, major obstacles are found among women on jobs and those who running their traditional business like; boutiques, parlor and embroidery. Descriptive analysis and Factor Analysis Model is used for data analysis. The results are proposed that females want to work and can manage their business self-sufficiently but due to social culture issues they are not taking any initiative to start a new business. Government does not support the female’s entrepreneurship and does not take action for providing the basic education to the females. The female entrepreneurship development is not only due to dearth of financial resources but also lack awareness for facilities available to develop their skills.

This paper proposes Artificial Neural Network (ANN) model for the required DC-DC Converter Duty Cycle feeding Maximum Power to resistive load to be used for distributed generation (DG) applications. It proposes a PV module when coupled to a load through DC-DC Converter to supply this resistive load with the maximum power from the PV module. Some of DC-DC converters topologies are discussed in brief with concentration on Cúk and SEPIC Converters operations. The mechanism of load matching is described to give the required converter duty cycle at maximum power point (MPP). Relations in 3D figures are introduced for the most probable situations for irradiance and temperature with the corresponding PV voltage and current. Also, 3D figures for the desired duty cycle, output voltage and current of DC-DC converter to gain the maximum power to the resistive load at various irradiance and temperature values. Moreover; Artificial Neural Network (ANN) is used to implement a neural model with its algebraic function to take the probable system situations and outs the proposed converter duty cycle to give maximum power for the load. All the neural model are done with their hidden and output layers’ suitable neurons numbers and suitable performance goals depending on the 3D simulation figures shown in the paper.

The detection of benzene vapor composition formed inside the cars cabin has been investigated. Benzene is an organic chemical compound. The sample of benzene vapor composition is taken from a cars cabin and then the samples are analyzed by the gas chromatography-mass spectrometer (GCMS). The data is recorded and plotted by using the 4000 GCMS version 6’s software. Finally, the results show that there are different gases compositions inside the cars cabin. Beside of the gas (Z)-1-(Ethoxycarbonyl-1-Fluoro-2-(Methoxycarbonyl)-1, 3-Butadiene, that found inside the cars cabin, there are other gases as - (3-Oxo-3H-Benzo [F] Chromen-2-Yl)-2, 4(1H,3H) - Quinolinedione, Ethane-D6, Ethylene-D4, Heptacosafluoro-Tributylamine, Nonanal, Decanal, Tetradecanoic Acid, 11-Dodecen-1-Al, benzeneethanamine, 3-fluoro-a, 5-dihydroxy-N-methyl-, 2-Pyridinepropanoic Acid, a-Methyl-a-Oxo-Ethyl Ester, Silane Methyl-, Hexadecanoic Acid.