Latest Articles Rss

Effects of Increased Physiological Arousal on Upper Extremity Positional Awareness in Healthy Young Adults

Problem statement: The purpose of this investigation was to examine the effects of increased physiological arousal on the ability to perceive upper extremity positional awareness in healthy young adults. Approach: Thirty-eight participants were pre- and post-tested for upper extremity positional awareness using a manual kinesthesiometer. Participants in the experimental group underwent a combination of the Stroop color-word task and timed arithmetic problems to produce a state of physiological arousal. Heart rate and blood pressure measurements were taken during data collection to assess levels of physiological arousal. Pre-and post-test absolute error scores for each participant were compared. Results: ANCOVA revealed a significant time effect (p<0.046) between pre and post-test trials for the experimental group. Conclusion: The results suggested positional awareness is altered under a state of elevated physiological arousal and that these results may have significant implications for individuals performing various types of motor skills.

Lippia graveolens and Carya illinoensis Organic Extracts and there in vitro Effect Against Rhizoctonia Solani Kuhn

Problem statement: Plant extracts with polyphenolic compounds obtained with different solvents have been evaluated against plant pathogens. However, most of these extract have been obtained using solvents no allowed under an organic production context. Approach: In the present research was to evaluate the inhibitory effect of polyphenolic extracts from L. graveolens and C. illinoensis, obtained with alternative organic solvents (lanolin and cocoa butter), water and ethanol against R. solani in order to determine the Inhibitory Concentration (IC₅₀) of each extract. Results: The results showed that extracts of both L. graveolens and C. illinoensis obtained with lanolin and ethanol (200 and 3000 ppm of total tannins, respectively) inhibited at 100% growth of R. solani. The IC50 for each extract was highly variable, low IC50 values were obtained with L. graveolens (4.50�10¹) and C. illinoensis (4.33�10²) extract using lanolin and ethanol respectively. Tannins extraction was strongly dependent on plant species and in the solvent used. Conclusion: The alternative organic solvents lanolin and cocoa butter allowed the recovery of polyphenols compounds with antifungal activity against R. solani.

Importance of Program Development Competencies for Agricultural Extension Agents� Performance in Process of Technology Transfer

Problem statement: The movement of technology from lab to the field has been a challenge for agricultural extension agents. In this study researchers focused on program development competencies for agricultural extension agents in process of technology transfer and discuss the importance of these competencies by determining the relationship between these competencies and performance of extension agents. Approach: The study employed stratified random sampling technique. The sample consisted of 210 extension agents in four states of Malaysia. The data were analyzed using descriptive statistics, Pearson correlation and multiple regression analysis. Results: Extension agents perceived themselves competent in developing program planning, program implementation and program evaluation. The findings supported the positive relationship between competencies and extension agents� performance. Therefore hypothesis of the study was supported. The results of multiple regressions showed program development competencies explained 0.448 of variance of extension agents� performance. Conclusion/Recommendations: It can be concluded that performance of extension agents is expected to increase if they have program development competencies. Results supported the importance of these competencies for performance of extension agents in process of technology transfer. Hence to keep extension agents competent and to further improve their performance, these competencies must be considered and upgraded. Continuous assessment of extension agents� competencies and performance is recommended.

Effect of Dietary Inositol on Growth, Feed Utilization and Blood Biochemical Parameters for Juvenile Barramundi (Lates calcarifer Bloch)

Problem statement: The utilization of inositol was detected for growth performance and erum biochemical parameters of juvenile barramundi (Lates calcarifer). Approach: A 56 day feeding trial was conducted to evaluate the effect of inositol on growth, feed utilization and serum biochemical parameters for juvenile barramundi Lates calcarifer (initial size 5.51�0.07g). Six experimental fish meal-based isonitrogenous (42% crude protein) and isolipidic (10% crude lipid) diets containing levels of inositol (350, 364, 458, 507, 720, 1050 mg kg^-1 diet) were formulated. Results: Fish fed diet containing inositol 507 mg kg^-1 diet had the significantly highest weight gain (WG, %) among all the groups (p<0.05) and had significantly lower Feed Conversion Ratio (FCR) than fish fed the diet containing inositol 458 mg kg^-1 diet (p<0.05). Survival and Hepatosomatic Index (HSI) were not significantly affected by graded levels of dietary inositol (p>0.05). However, significantly lower Viscerasomatic Index (VSI) was found in fish fed diet without supplemental inositol (p<0.05). Dietary inositol levels did not affect whole body moisture, crude protein and lipid contents (p>0.05). Total protein and triacylglycerol in serum increased with increasing dietary inositol levels up to 507 mg kg^-1 diet (p<0.05). The significantly lowest blood urea nitrogen was found in fish fed dietary inositol 458 mg kg^-1 diet among all groups except for 720 mg kg^-1 diet. Total Cholesterol (TC) of fish fed dietary inositol 507-1050 mg kg^-1 diet was higher than those of fish fed dietary inositol 350-458 mg kg^-1 diet. Conclusion: Results of the present investigation demonstrated significant improvement of growth and feed utilization of juvenile barramundi can be achieved by inositol supplementation at 507 mg kg^-1 diet.

Subsample Goal Model for Multihalver on Outliers

Problem statement: In this study, a delete-half jackknife problem reformulated as a subsample multihalver was presented. Approach: In this respect, exploiting outlier nomination and estimation, since considering all possible half-sample is unpractical and unfeasible were considered. Results: We derived subsample algorithm which is unbiased multihalver and the performance of the model in formulating the subsample multihalver was shown. Conclusion: The result of subsample multihalver method of nomination and estimation is better way of resolving large population.

A Random Walk Model for Stock Market Prices

Problem statement: The stock exchange market has been one of the most popular investments in the recent past due to its high returns. The market has become an integral part of the global economy to the extent that any fluctuation in this market influences personal and corporate financial lives and the economic health of a country. The daily behavior of the market prices revealed that the future stock prices cannot be predicted based on past movements. Approach: In this study, we analyzed the behavior of daily return of Nigerian stock market prices. The sample included daily market prices of all securities listed in the Nigeria Stock Exchange (NSE). Results: The result from the study provided evidence that the Nigerian stock exchange is not efficient even in weak form and that NSE follow the random walk model. The idealized stock price in the Nigerian stock exchange is a martingale. Conclusion: Martingale defines the fairness or unfairness of the investment and no investor can alter the stock price as defined by expectation.

A Study of Naghdi�s Shell with a Unilateral Contact of a Rigid Obstacle

Problem statement: In this study we considered a shell modeled by Naghdi�s equations with a unilateral contact of a rigid body. Approach: This model has been studied by Blouza and Le Dret (1994b) but without contact. Results: In this study, we studied the existence, uniqueness and continuity of the deformation of this shell with respect to the data. Conclusion: We proposed to approximate the model by a finite element method.

Spline Estimator in Multi-Response Nonparametric Regression Model with Unequal Correlation of Errors

Problem statement: In many applications two or more dependent variables are observed at several values of the independent variables, such as at time points. The statistical problems are to estimate functions that model their dependences on the independent variables and to investigate relationships between these functions. Nonparametric regression model, especially smoothing splines provide powerful tools to model the functions which draw association of these variables. Approach: Penalized weighted least-squares was used to jointly estimate nonparametric functions from contemporaneously correlated data. We apply Generalized Maximum Likelihood (GML), Generalized Cross Validation (GCV) and leaving-out-one-pair Cross Validation (CV) for estimating the smoothing parameters, the weighting parameters and the correlation parameter Results: In this study we formulated the multi-response nonparametric regression model with unequal correlation of errors and give a theoretical method for both obtaining distribution of the response and estimating the nonparametric function in the model. We also estimate the smoothing parameters, the weighting parameters and the correlation parameter simultaneously by applying three methods GML, GCV and CV. Conclusion: Distribution of responses is normal. With multiple correlated responses it is better to estimate these functions jointly using the penalized weighted least-squares.

An Instant of Performance Criteria for Outlier Identification

Problem statement: Different approach to deal with criteria for multivariate outlier identification procedures when it was studentized was presented. Approach: In this respect, associated unpractical dynamic linear model and outlier identification were considered. Results: A resultant studentized Becker outlier version for multivariate outlier was obtained, as an improvement on the original model. Conclusion: The studentized Becker multivariate outlier incorporated the modeling change in an evolving extension.

Hybrid Connection Simulation Using Dynamic Nodal Numbering Algorithm

Problem statement: The traditional dynamic nodal numbering algorithm was proposed for generating code number to support truss and frame simulation using only one element type, frame element; it facilitates the software development process. The traditional algorithm, however, supports simulation of only two types of connection: Hinged connection and rigid connection. In many cases, the problems consist of mix-connection and hybrid connection which cannot be simulated by the traditional technique directly. Approach: In this research, an improvement of dynamic nodal numbering algorithm was proposed to support hybrid connection simulation. It required only one frame element to simulate hinged, rigid and also various hybrid connection types. Results: The implemented software following the new algorithm was tested with two hybrid structure examples. The analysis results are shown in term of shear force, bending moment and axial force. Conclusion: The proposed algorithm does not only improve the ability of connection simulation, but it is also more convenient to implement, debug and expand the finite element software. Hence it reduces the cost, time and effort in developing the computer software.

Voltage Oriented Control Applied to a Grid Connected Photovoltaic System with Maximum Power Point Tracking Technique

Problem statement: This study presented a grid connected photovoltaic system with voltage oriented control. This system contains the problem of degradation of photovoltaic power with climatic factors and the problem of synchronization of currents to be injected to the grid. Approach: In order to optimize the photovoltaic energy generation, we developed a new maximum power point tracking algorithm and we use a phase locked loop to solve the problem of synchronization of grid voltage and current. Results: The model of the grid connected photovoltaic system had been implemented in the MATLAB/SIMULINK software and simulation studies have been presented. Conclusion: Results had proved the effectiveness of the proposed system, the utility of the maximum power point tracker and the robustness of the phase locked loop.

An Experimental Comparison Between Demand Systems of Major Food Groups in Urban Economics

Problem statement: This study examined the eleven major food groups demand for urban areas of Iran during1361-1386. Approach: AIDS, ROTTERDAM, CBS and NBR models was compare together and Sur method was applied for estimating of systems, too. Results: Results of study showed cream and fresh fruits have smallest and largest income elasticity, respectively. Also, cream, bread, dairy, egg, fresh vegetables, oils and fats and sugar and products, are necessary, meat, fresh fruits and dried fruit are luxury and grain is only inferior group, too. The exception meat, dried fruit and sugar and its products, other groups are inelastic than own price changes. Also, among them, grain and dried fruit are most inelastic and most elastic, respectively. That means that demand for them has smallest and largest sensitivity than own price influences. Also, cross price elasticity�s represented that nor of the groups, are gross strictly substitute, together and gross substitute among them is weak. About complement relation, should say fresh fruits and oils and fats are gross strictly complement for cereal and sugar and its products, respectively and gross complement relation among other groups is found weak. Conclusion: AIDS was better than other models and should be apply for analysis of major food group demand for urban areas of Iran, alternatively.

A Novel Method for Testing Digital to Analog Converter in Static Range

Problem statement: Linearity testing methods for DAC usually involves usage of non-linear analog components, which are indeed prone to various errors. Few other testing methodologies involve complex circuitry for measuring exactitude of DAC. Practically, it is difficult to build those as Built In Self Test (BIST) due to complexity of calculation, which demands more usage of ALU (or core of processing unit). This research aims to optimize and simplify the design of DAC testing scheme, while minimizing the computational overhead. Henceforth, the testing technique can be brought on to BIST level circuitry. Approach: A slope generator (more commonly known as integrator) produces a Ramp type of output voltage when it is fed with a DC voltage, slope of ramp depends upon the magnitude of DC-voltage. These varying slopes, when converted into a useful number, can provide some information, regarding voltage level of input. Results: In this research, we replace the DC input of the Slope generator by analog output of DAC, which is under test. As the output of DAC varies according to the Digital code input, various slopes can be generated. These slopes are converted here into useful numbers called tick counts, by measuring the time taken by Ramp type output to cross a defined threshold voltage interval. The proposed method makes use of an integrator to produce a ramp signal of high precision and conditioned slope. The actual slope produced by the output of the DAC is compared with the expected slope by counting the number of clock ticks. Conclusion: This system of using Time Tick based BIST eludes the usage of high precision non-linear devices like ADCs to test DACs. Also this system reduces exigency of separate ALU for computing error.

Determination of Kinetic Parameters of a Super Heavy Chisel Plow Under Various Operating Conditions

Problem statement: Tillage is a process of creating a desirable soil condition for seed germination and growth. The tillage of soil is considered to be one of the biggest farm operations as the tillage operation requires the most energy on the farm. Chisel plow is widely used by farmers as a primary tillage tool. Performance data for chisel plow operation is essential in order to reduce the cost of tillage operation. Approach: Field experiments were conducted using a fully instrumented MS 3090 tractor to measure the draft of a super heavy chisel plow in a sandy soil over wide ranges of plowing depths and forward speeds. The data were measured and recorded using an instrumentation system and data logger. Results: The effects of plowing depth and forward speeds on draft, unit draft, vertical specific draft, horizontal specific draft and coefficient of pull were evaluated. The results indicated that increasing the plowing depth and/or the forward speed increased the draft, unit draft and vertical specific draft. Also, increasing the plowing depth increased the horizontal specific draft and the coefficient of pull, while increasing the forward speed decreased the horizontal specific draft and the coefficient of pull. Conclusion: About 21.8% of the draft force was directed towards cutting the soil and 78.2% was consumed in pulverization of soil particles. The values of the vertical specific draft were much higher than those of the horizontal specific draft for all plowing depths and forward speeds. The plowing depth had more pronounced effect on the draft, unit draft, specific draft and coefficient of pull than the forward speed. The optimum forward speed was 1.75 m sec^-1. The recommended plowing depth should be based on the type of crop (depth of the root system).

Link Stability and Node Energy Conscious Local Route-Repair Scheme for Mobile Ad Hoc Networks

Problem statement: A mobile ad hoc network is a self-configuring network of mobile nodes connected by wireless links. As the nodes are free to move randomly, topology of the network may change rapidly and unpredictably. As a result, intermediate nodes in the communication routes tend to lose connection with each other during the communication process. In order to repair a broken link, an end-to-end (from source to destination) route discovery is typically performed to establish a new route for communication. The mechanism results in huge communication overhead and long delay in completion of the communication. So, it is rational to locally repair a link, as much as possible, than to discover a whole new route. Approach: In the present article, we proposed a Link Stability and Node Energy Conscious (LSNEC) local route repair scheme for mobile ad hoc networks. In case of breakage of a link from node n_a to another node n_b in between a communication session, LSNEC instructs n_a to broadcast a ROUTE-REPAIR message within its radio-range specifying n_b or any successor of n_b in the broken route, as a desirable destination. If any node residing within the radio-range of n_a has an already established single/multi-hop path to any one of those destinations mentioned in the ROUTE-REPAIR message, it sends a REPAIR-ACK message back to n_a. Attributes of REPAIR-ACK include the identification number (s) of the destination (s) as well as identification numbers, geographical positions (in terms of latitude and longitude), radio-ranges and residual energies of nodes present in the associated path to that destination along with the intuitively computed stability of links between the consecutive nodes. The stability is computed depending upon relative velocities of the involved nodes, distance between them and the history of survival of the link. The optimal path is chosen depending upon the residual energy of nodes, stability of links and number of hops in that path. Results: In simulations we compared the LSNEC embedded versions of the protocols Ad hoc On-demand Distance Vector routing (AODV) and Associatively Based Routing (ABR) with their ordinary versions as well as PATCH and �Quick Local Repair� scheme (to be referred to as QLR subsequently in this study) embedded versions. Both PATCH and QLR are well-known local repairing schemes for ad hoc networks. It is found that, LSNEC-AODV dramatically saves 57% control overhead compared to ordinary AODV, 32.7% compared to PATCH-AODV and 36.3% compared to QLR-AODV. Similarly, LSNEC-ABR saves 29.3% control overhead than ordinary ABR, 10.7% than PATCH-ABR and 12.8% than QLR-ABR. Accordingly decrease the power consumption of network nodes and delay in recovery. Conclusion: The simulation results emphatically illustrated the performance benefit of our proposed scheme LSNEC compared to the other state-of-the-art local route-repair schemes, in respect of control overhead, overall energy consumption of the network, data packet delivery ratio and route recovery delay. LSNEC has its application wherever an ad hoc network is used. Please note that ad hoc networks are extremely useful in military and other tactical applications such as emergency rescue, exploration missions and other scenarios w here cellular infrastructure is unavailable.

Increasing the Reliability of Fuzzy Inference System-Based Skin Detector

Problem statement: Skin detection is a common primitive for many human-related image processing applications, such as video surveillance, naked image filters and face detection. Skin color is considered as a useful and discriminating spatial feature for many applications, but it is not robust enough to deal with complex image environments. Skin tones range from dark (some Africans) to light white (Caucasians and some Europeans). In addition, both the light-changing conditions and the existence of objects with skin-like colors could cause some major difficulties faced pixel-based skin detector depending only on a color feature. Approach: This study proposed a novel Fuzzy Inference System (FIS) for skin detection, which combines both color and texture features. To increase the reliability of the skin detection process, neighborhood pixel information is incorporated into the proposed method. The color feature is represented using RGB color model, while the texture feature is estimated using three statistical measures: standard deviation, entropy and range. The subtractive clustering-based fuzzy system method and the Sugeno type reasoning mechanism are used for modeling FIS-based skin detection. The proposed approach builds a fuzzy model of skin detection from existing images within skin and non-skin regions (output data) and from both color and texture features of the skin regions (input data). Results: The proposed skin detection method achieved a true positive rate of approximately 90% and a false positive rate of approximately 0.22%. Furthermore, this study analyzes and compares the obtained results from the proposed skin detection with threshold-based skin detector to show the level of robustness, using both color and texture features in the proposed skin detector. Conclusion: It was found that a skin detector based on both color and texture features can lead to an efficient and more reliable skin detection method compared with other state-of-the-art threshold-based skin detectors. The proposed detector reduces the FP rate to 0.22% compared with a skin detector based on predefined color rules.

Geopolitical Constructs Understanding and Survey with Constructivism Geography Approach Case Study: IRI and Its Confronting Challenges in Central Asia

Problem statement: After dissolution of Soviet Union, both of political geography system and dominance ideational structure have deconstructed in central Asia region. In year of 1979 with revolution, Iranian actors was accepted the Islamic republic system in their country, so new actors, structure and exigencies were revealed in Iran and central Asia relations, that cause create new challenges in confronting of Islamic republic of Iran government. Our fundamental question in this research is that: How geopolitical constructs have constituted confronting challenges for Islamic republic of Iran in Central Asia region? Approach: Therefore in this study we tried to explain the question in geographical framework and constructivism approach (on ground as constructivism geography). We had utilized qualitative research method and hermeneutic-positivist procedure in this study. As attention implicated question, the purpose of this article is understand challenges how constitute in reason of geopolitical constructs. Results: Differences in geopolitical constructs, between Iran and countries of central Asia region and also being harmonious construct, these countries with the present actors in the region, has caused an opposition in regional anarchic system between IRI and these countries in region and actors in the region and also form of distribution of capabilities between actors which has caused challenges for IRI. Conclusion: For following its goals against, high level fruition enemies of IRI like USA, Israel and Russian, China competitors from distribution of capabilities in national and international caused many challenges and double-deficiency for IRI.

Evidence-Based Study on Performance Evaluation of Social Education Institutions with Balanced Scorecard

Problem statement: Based on the concept of Balanced Scorecard (BSC), this study was intended to assist the establishment of performance evaluation system for social education institutions in transforming phase. Approach: An evidence-based analysis was processed to examine the objectivity of the indicators and the weights of key factors of the current performance evaluation. Results: Based on the concept of BSC, literature analysis, expert interviews and Analytic Hierarchy Process (AHP), this study investigated the propriety of the performance management indicators currently used by social education institutions in transforming phase, with the intention to establish a more objective and practical system. Conclusion: The advantage of this study it can provide a practical framework for will construct and carry out the management system of the performance evaluation for other social education institutions in the future.

Relationships Between Background Factors and Female Marital Satisfaction

Problem statement: In spite of the importance of marital satisfaction in couple relation, there is a little research in the Iranian context that examined the relationship between background factors and marital satisfaction. Thus, this study examined the relationship between duration of marriage, number of children, years of education and family income with female marital satisfaction. Approach: The study was carried out among a sample of 337 wives in Shiraz City, Iran. The Kansas Marital Satisfaction (KMS) was used to measure marital satisfaction. The study employed correlations test to determine the relationships between duration of marriage, number of children, years of education and family income with marital satisfaction. Results: The study found that there were no significant relationships between duration of marriage and family income and marital satisfaction. There was a negative significant relationship between respondents� age and number of children and marital satisfaction. There was a positive significant relationship between respondents� years of education and marital satisfaction. The Multivariate Regression Analysis was used to answer the last objective. The analysis showed that the predictor variable, women age, was found to be significant in explaining the observed variation in marital satisfaction (DV). Conclusion: Generally, the final model has explained 4% of total observed variance to marital satisfaction.

Predicting Insurance Investment: A Factor Analytic Approach

Problem statement: In the last decade growing attention has been paid to the pattern of investments by the insurance industry and the question of how to evaluate such investments. In an economy where the capital market is huge and active, mathematical considerations come into play in the selection of investments to ensure yield maximisation. Approach: This study examined the use of factor analysis as an emerging technique for the analysis of insurance investment in Nigeria. Results: The proposed technique described a number of methods designed to analyze interrelationships within the investment variables in terms of few underlying but unobservable random quantities called factors. The factors were constructed in a way that reduces the overall complexity of the data by taking advantage of inherent interdependencies. Conclusion: The result obtained through this approach were promising and shows that two principal components of the factor loadings have a cumulative proportion of variance accounted for 94.5% of the total variations of the investments pattern.

VHDL Modeling, Simulation and Prototyping of a Novel Arbitrary Signal Generation System

Problem statement: Arbitrary signal generators play an important role in many applications. Several different techniques utilizing both analog and digital approaches are being used for the generation of periodic signals. However, all of them suffer from many drawbacks. In this study, we present modeling, simulation and prototyping of a novel periodic arbitrary signal generation system using FPGAs. The proposed system utilizes orthogonal functions to generate a variety of periodic arbitrary signals. Approach: A new approach for designing arbitrary signals utilizing Walsh and Rademacher functions had been used. The design had been done using state-of-the-art high level design techniques and has been targeted to the latest available FPGA chips from Xilinx and Altera. Results: The simulation results demonstrated both the digital and analog versions were presented. It was found that all the signals generated showed precisely zero error and the signal generated was exactly the same as the desired one. Conclusion: Excellent accuracy with zero error is achieved. The designed and implemented Arbitrary signal Generation System is stand-alone and doesn�t require the support of any computer hardware or software, as was needed in earlier attempts It has been concluded that virtually any periodic signal can be generated using the technique developed.

VLSI Implementation of Novel Class of High Speed Pipelined Digital Signal Processing Filter for Wireless Receivers

Problem statement: The need for high performance transceiver with high Signal to Noise Ratio (SNR) has driven the communication system to utilize latest technique identified as over sampling systems. It was the most economical modulator and decimation in communication system. It has been proven to increase the SNR and is used in many high performance systems such as in the Analog to Digital Converter (ADC) for wireless transceiver. Approach: This research presented the design of the novel class of decimation and its VLSI implementation which was the sub-component in the over sampling technique. The design and realization of main unit of decimation stage that was the Cascaded Integrator Comb (CIC) filter, the associated half band filters and the droop correction are also designed. The Verilog HDL code in Xilinx ISE environment has been derived to describe the proposed advanced CIC filter properties. Consequently, Virtex-II FPGA board was used to implement and test the design on the real hardware. The ASIC design implementation was performed accordingly and resulted power and area measurement on chip core layout. Results: The proposed design focused on the trade-off between the high speed and the low power consumption as well as the silicon area and high resolution for the chip implementation which satisfies wireless communication systems. The synthesis report illustrates the maximum clock frequency of 332 MHz with the active core area of 0.308�0.308 mm². Conclusion: It can be concluded that VLSI implementation of proposed filter architecture is an enabler in solving problems that affect communication capability in DSP application.

Flexural Behaviors of Damaged Full-Scale Highway Bridge Girder Strengthened by External Post Tension

Problem statement: Prestressed Concrete (PC) I section girder with Reinforced Concrete (RC) topping slab has been widely applied to long span bridge girders for several years. A bridge girder is subjected to severe conditions caused by an aggressive environment and overloading. A crack can be initiated and propagate when the tensile stress exceeds the tensile strength of concrete due to overloading. Deterioration of the girder may be caused by a wide crack due to corrosion of the reinforcement and other mechanisms. Prestressing force and flexural stiffness (EI) of PC-I section girder are reduced depending on the level of overloading and the corresponding damage. Approach: Full scale tests of Type III AASHTO highway girder with a 20 cm thick RC topping slab were performed to study both the degradation process due to overloading and also the effects of external post-tension in the recovery of structural performance of a damaged highway PC bridge girder. Results: The results showed that degradation, loss of internal prestressing force in the PC-I girder and flexural stiffness of the composite girder depend directly on Damage Index (DI) expressed in terms of permanent deformation. External post tension with three levels of prestressing forces was applied to strengthen the damaged girder to recover its structural performance, flexural stiffness and strength. A simplified analytical model, verified by test results, was developed to predict flexural behaviors, loss of internal prestressing force and flexural stiffness of highway girder due to overloading and also structural performance of the strengthened girder. Conclusion: It was found that the required external prestressing force to effectively recover structural performance of a damaged girder depended directly on the damage index of the girder.

Optimization of Mix Proportion of High Performance Mortar for Structural Applications

Problem statement: Mortar mix is a major construction material in fabrication of ferrocement structural elements. However, there have been scarce amount of technical data available on suitable mix proportion to achieve structural grade mortar with specific strength requirement and adequate level of workability for proper placement into construction formwork. Moreover, current practice in ferrocement construction work which uses mortar mix with cement: sand ratio ranging between 1:1.5 to 1:2 incurs high requirement of cement yet producing mix with suboptimum level of compressive strength. Approach: An experimental investigation was carried out to evaluate workability and compressive strength properties of structural grade mortar mixes with various cement: sand ratios ranging from 1:2.0-1:2.75 and varying water/binder ratio between 0.35 and 0.50. Throughout the laboratory investigation, a total of 28 batches of mortar mixes with various mix proportion were designed, cast and tested in accordance to relevant standards of practice prescribed by British Standard Institute (BSI) and American Society of Testing Material (ASTM). Results: At the end of the laboratory investigation program, high performance mortar mix with compressive strength exceeding 55 MPa and slump level within 50-90 mm which is suitable for heavy duty ferrocement construction work was successfully developed. Moreover, data on mix proportion for several other grades of mortar mixes ranging from grade 35 to grade 55 were also derived. Conclusion: It was found that optimum cement: Sand ratio of structural mortar is 1:2.25. With the use of this cement: Sand ratio in the production of structural grade mortar mix in fabrication of ferrocement structural elements, consumption of cement binder will be economized hence resulting in potential savings in term of material and production cost of mortar mix in the construction industry. Besides, it was also observed that strengths of mortar mixes do not vary linearly with cement content of the mix.

Modeling Method of a Low-Pass Filter Based on Microstrip T-Lines with Cut-Off Frequency 10 GHz by the Extraction of its Wave-Scattering Parameters from its Causal Bond Graph Model

Problem statement: This study presented a jointly application of bond graph technique and wave-scattering formalism for a new realization called scattering bond graph model which has the main advantage to show up explicitly the different wave propagation. Approach: For that, we proposed to find the scattering matrix from the causal bond graph model of a low-pass filter based on Microstrip lines and with cut-off frequency 10 GHz, while starting with determination of the integro-differentials operators which is based, in their determination, on the causal ways and causal algebraic loops present in the associated bond graph model and which gives rise to the wave matrix which gathers the incident and reflected waves propagation of the studied filter. Results: The scattering parameters, founded from the wave matrix, will be checked by comparison of the simulation results. Conclusion: Thereafter, we use a procedure to model directly this scattering matrix under a special bond graph model form often called �Scattering Bond Graph Model�.

Merging Autopilot/Flight Control and Navigation-Flight Management Systems

In this abstract the following commercial aircraft 3 avionics systems will be merged together: (1) Autopilot Flight Director System (APFDS), (2) Flight Control System (FCS) and (3) Flight Management Systems (FMS). Problem statement: These systems perform functions that are dependant and related to each other, also they consists of similar hardware components. Each of these systems consists of at least one computer, control panel and displays that place on view the selection and aircraft response. They receive several similar sensor inputs, or outputs of one system are fed as input to the other system. By combining the three systems, repeated and related functions are reduced. Since these systems perform related functions, designers and programmers verify that conflict between these systems is not present. Combining the three systems will eliminate such possibility. Also used space, weight, wires and connections are decreased, consequently electrical consumption is reduced. To keep redundancy, the new system can be made of multiple channels. Approach: The new system (called Autopilot Navigation Management System, APNMS) is more efficient and resolves the above mention drawbacks. Results: The APFDS system functions (as attitude-hold or heading-hold) are merged with the FCS system main function which is controlling flight control surfaces as well as other functions as flight protection, Turn coordination and flight stability augmentation. Also the Flight Management system functions (as flight planning, aircraft flight performance/engine thrust management) are merged in the new system. All this is done through combining all 3 systems logic software�s. Conclusion/Recommendations: The new APNMS system can be installed and tested on prototype aircraft in order to verify its benefits and fruits to the aviation industry.

Reliability Assessment of Buckling Strength for Compressed Cylindrical Shells with Interacting Localized Geometric Imperfections

Problem statement: Elastic cylindrical shells are common structures in the fields of civil engineering and engineering mechanics. These thin-walled constructions may undergo buckling when subjected to axial compression. Buckling limits to large extent their strength performance. This phenomenon depends hugely on the initial distributed or localized geometric imperfections that are present on the shell structure. Localized geometric imperfections result in general from the operation of welding strakes to assemble the shell structure. In this study, reliability of buckling strength as it could be affected by shell material and geometry parameters was investigated. The localized geometric imperfections were chosen to be entering and having either a triangular or a wavelet form. Interaction between three localized imperfections had also been considered. Approach: A special software package which was dedicated to buckling analysis of quasi axisymmetric shells was used in order to compute the buckling load via the linear Euler buckling procedure. A set of five factors including shell aspect ratios, defect characteristics and the distance separating the localized initial geometric imperfections had been found to govern the buckling problem. A parametric study was performed to determine their relative influence on the buckling load reduction. Reliability analysis was carried out by using first order reliability method. Results: Wavelet imperfection was found to be more severe than triangular form in the range of low amplitude imperfections. It was shown also by comparison with the single imperfection case that further diminution of the critical load is obtained for three interacting imperfections. The interval distance separating the localized geometric imperfections was found to have important influence on the reliability index. Conclusion/Recommendations: In the he range of investigated parameters, reliability was found to increase with the distance separating the localized geometric imperfections. This can help performing optimal design of assembled strakes.

Modeling and Analysis of MRR, EWR and Surface Roughness in EDM Milling through Response Surface Methodology

Problem statement: Electrical Discharge Machining (EDM) has grown over the last few decades from a novelty to a mainstream manufacturing process. Though, EDM process is very demanding but the mechanism of the process is complex and far from completely understood. It is difficult to establish a model that can accurately predict the performance by correlating the process parameters. The optimum processing parameters are essential to increase the production rate and decrease the machining time, since the materials, which are processed by EDM and even the process is very costly. This research establishes empirical relations regarding machining parameters and the responses in analyzing the machinability of the stainless steel. Approach: The machining factors used are voltage, rotational speed of electrode and feed rate over the responses MRR, EWR and Ra. Response surface methodology was used to investigate the relationships and parametric interactions between the three controllable variables on the MRR, EWR and Ra. Central composite experimental design was used to estimate the model coefficients of the three factors. The responses were modeled using a response surface model based on experimental results. The significant coefficients were obtained by performing Analysis Of Variance (ANOVA) at 95% level of significance. Results: The variation in percentage errors for developed models was found within 5%. Conclusion: The developed models show that voltage and rotary motion of electrode are the most significant machining parameters influencing MRR, EWR and Ra. These models can be used to get the desired responses within the experimental range.

Neural Network Change Detection Model for Satellite Images Using Textural and Spectral Characteristics

Problem statement: Change detection is the process of identifying difference of the state of an object or phenomena by observing it at different time. Essentially, it involves the ability to quantify temporal effects using multi-temporal data sets. Information about change is necessary for evaluating land cover and the management of natural resources. Approach: A neural network model based on both spectral and textural analysis is developed. Change detection system in this study is presented using modified version of back-propagation-training algorithm with dynamic learning rate and momentum. Through proposed model, the two images at different dates are fed into the input layer of neural network, in addition with Variance, Skewness and Eculedian for each image that represent different texture measure. This leads to better discrimination process. Results: The results showed that the trained network with texture measures achieve 23% higher accuracy than that without textural parameters. Conclusion: Adding textural parameters of satellite images through training phase increases the efficiently of change detection process also, it provides adequate information about the type of changes. It also found, when using dynamic momentum and learning rate, time and effort needed to select their appropriate value is reduced.

The Intracerebroventricular Administration of W-7, A Calmodulin Inhibitor, Attenuate the Development of Morphine Tolerance in Rats

Problem statement: The present study was performed to determine the effect of Intracerebroventricular (ICV) administration of W-7, a specific calmodulin inhibitor, on the analgesic effect and development of tolerance to antinociceptive effect of acute and chronic morphine administration respectively. Approach: This study was carried out on male wistar rats, weighing 200-250 g. For acute experimental protocol, Morphine was injected intraperitonealy in a single dose (5 mg kg^-1). For chronic experimental protocol, Morphine was administered daily (15 mg kg^-1 for 8 days). The threshold to thermal nociceptive stimuli was measured by tail-flick test. In acute and chronic experiments, W-7 (0.25, 0.5 and 1 �mol/rat) was injected through ICV at different paradigms. Maximal Possible Effect percentage (MPE%) was considered as analgesia index. Results: Our result showed that W-7 (0.25, 0.5 and 1 �mol/rat) injections before acute morphine administration significantly reduced the analgesic effect of morphine compared with morphine treated group (all p<0.05). Chronic morphine exposure induced tolerance to its antinociceptive effect and administration of W-7 (0.5 and 1 �mol/rat) decreased the development of tolerance to it. Conclusion: In conclusion these data showed that acute administration of W-7 reduced the analgesics effect of morphine and chronic injection of W-7 inhibited the development of morphine tolerance which indicates that calmodulin and its dependent pathways may play a role in the morphine tolerance processes.