Open Access Letter to the Editor

Low Latency, Low Power in A. I. Perception Modules Development and Implementation for Autonomous Driving

Rajdip Das

Journal of Engineering Research and Reports, Page 5-6
DOI: 10.9734/jerr/2021/v20i917368

Self-service vehicles can combine data to boost the understanding of that of other cars, and thus improve safety drive and identification performance. However, it is burdensome to share in between autonomous vehicles, because due to the quantity of data generated by different vehicle types of sensors. In the search for ever faster and more efficient computing, researchers and manufacturers are busy exploring novel processing architectures. Among these, neuromorphic engineering, the emulation of brain function inside computer chips are showing particular promise for applications involving deep learning, an increasingly common form of artificial intelligence (AI) that uses neural networks inspired by brains to uncover patterns in large datasets. In this research, we will examine an ultra-low-power protocol related to low-latency data exchange and Deep Learning Neural Network (DLNN) using neuromorphic computing for addressing AI perception issues in autonomous driving.

Open Access Original Research Article

Wire Shorting Defect Mitigation on Substrate LGA Device Through Wirebond Capillary Adjustment

Jonathan Pulido, Frederick Ray Gomez, Raymond Albert Narvadez

Journal of Engineering Research and Reports, Page 1-4
DOI: 10.9734/jerr/2021/v20i917367

Semiconductor packaging technologies are getting more challenging with regards to assembly manufacturing due to several factors such as complex package layout, process and machine capability, and materials compatibility. This paper discusses the wirebonding process difficulty and the solution to mitigate the wire-to-wire shorting defect on a substrate land grid array (LGA) device that causes low yield on engineering trials. Using a high-speed camera equipment, the actual process was monitored. It was then noticed that the cause of wire-to-wire shorting issue was a capillary hitting on previous wire. Ultimately, with the new capillary design and process optimization, wire-to-wire shorting defect was successfully mitigated.

Open Access Original Research Article

Assembly Wirebond Process Solution for Mitigating Leadframe Bouncing on Multi-Die QFN Device

Raymond Albert A. Narvadez, Frederick Ray I. Gomez, Anthony R. Moreno, Edwin M. Graycochea Jr.

Journal of Engineering Research and Reports, Page 7-12
DOI: 10.9734/jerr/2021/v20i917369

Modification and improvement of an existing tooling design in semiconductor packaging industry has been a usual practice, to enhance the current setup and to provide a solution to a specific assembly problem. This paper discusses the solution in eliminating the smashed ball defect occurrence observed after wirebond process. Smashed ball is usually encountered if the unit is unstable and creates a bouncing effect during wirebond process. It is therefore important to mitigate this micro-bouncing effect by analyzing the package design and the window clamp and top plate (WCTP). The objective is to increase the stability of the unit during wirebonding, especially for quad-flat no-leads (QFN) package with no tape. To achieve this, the solution is to alter the vacuum hole design of the top plate from single hole per unit to multiple holes of varied sizes per unit. Ultimately, after changing the design of the top plate, the micro-bouncing encountered during wirebond process was significantly reduced. This in turn created a consistent ball formation in all bonded wires. The comparative data presented in this paper confirmed the effectivity of the redesigned WCTP. For future works and studies, the improvement and learnings could be used on devices with comparable configuration.

Open Access Original Research Article

Resolution of Low IMC on Multi-Stacked Dice Device with Different Bond Pads

Freddie B. Folio, Roy B. Guingab, Frederick Ray I. Gomez, Jonathan C. Pulido

Journal of Engineering Research and Reports, Page 13-17
DOI: 10.9734/jerr/2021/v20i917370

The continuing advances of die technology of integrated circuits (IC) miniaturization bringing more complexity in the product. At unusual conditions one may encounter new challenges intrinsic to the structure of the package. The study aims to qualify a product such as multi-stacked dice configurations with baseline reference using same die technology. The only difference is the substrate layout in which defined for the electrical purpose. The challenge is to understand and resolve low intermetallic coverage (IMC) on each die which may lead to manufacturability and reliability problems over time.

Open Access Original Research Article

Impact of Curing Methods on the Porosity and Compressive Strength of Concrete

Francis Kwesi Nsakwa Gabriel-Wettey, Kennedy Appiadu-Boakye, Firmin Anewuoh

Journal of Engineering Research and Reports, Page 18-30
DOI: 10.9734/jerr/2021/v20i917371

An experimental investigation was conducted to evaluate the impact of different curing practices on the porosity and compressive strength of concrete. The targeted compressive strength of the concrete at 28-day of curing was 20 N/mm2. Plain concrete cubes were prepared with a mix ratio 1:1.5:3 by weight and 0.6 water-cement ratio. A total of 120 concrete cubes were tested on 7th, 14th, 21st, 28th and 56th day curing periods for slump, porosity and compressive strength. The four curing methods used were immersion, jute sack, plastic sheet and sprinkling which were all carried out in the laboratory under the same average environmental conditions of 27 ± 20°C temperature and 75% relative humidity. The results from the study showed that slump values were within the range of 52mm to 58mm which is within the medium range of 25 to 100mm, hence a true slump was achieved. The porosity of all samples decreased with age (i.e. at the dried state, immersion recorded the lowest 4.35%, followed by jute sack with 5.25%, plastic sheet 5.29% and sprinkling 5.55%). Again, the pattern of increases in concrete density (immersion curing produced concrete with the highest mean densities of 2369 kg/m3, jute 2360 kg/m3 ,plastic sheet 2277 kg/m3, sprinkling 2229 kg/m3 all for 56 days) was similar to that of the compressive strength (i.e immersion curing method yielded the highest compressive strength of 25.43 N/mm2, jute method 23.90 N/mm2, plastic method 23.47 N/mm2 , sprinkling method 22.33 N/mm2 for 56 days curing ages respectively). Therefore, increases in both compressive strength and densities of concrete cube is a function of curing method. The study concludes that the immersion curing method has the greater effect on the properties of concrete since it yielded the highest strengths. The recommendation is made for further studies on the impact of curing methods on the porosity and compressive strength of concrete on the field since this study was done in the laboratory under control conditions.

Open Access Original Research Article

Multi-Mean Scout Particle Swarm Optimization (MMSCPSO) based Reactive Power Optimization in Large-Scale Power Systems

Christophe Bananeza, Sylvère Mugemanyi, Théogène Nshimyumukiza, Jean Marie Vianney Niyodusenga, Jean De Dieu Munyaneza

Journal of Engineering Research and Reports, Page 31-42
DOI: 10.9734/jerr/2021/v20i917372

The particle swarm optimization (PSO) is a population-based algorithm belonging into metaheuristic algorithms and it has been used since many decades for handling and solving various optimization problems. However, it suffers from premature convergence and it can easily be trapped into local optimum. Therefore, this study presents a new algorithm called multi-mean scout particle swarm optimization (MMSCPSO) which solves reactive power optimization problem in a practical power system. The main objective is to minimize the active power losses in transmission line while satisfying various constraints. Control variables to be adjusted are voltage at all generator buses, transformer tap position and shunt capacitor.  The standard PSO has a better exploitation ability but it has a very poor exploration  ability. Consequently, to maintain the balance between these two abilities during the  search process by helping particles to escape from the local optimum trap, modifications were made where initial population was produced by tent and logistic maps and it was subdividing it into sub-swarms to ensure good distribution of particles within the search space. Beside this, the idle particles (particles unable to improve their personal best) were replaced by insertion of a scout phase inspired from the artificial bee colony in the standard PSO. This algorithm has been applied and tested on IEEE 118-bus system and it has shown a strong performance in terms of active power loss minimization and voltage profile improvement compared to the original PSO Algorithm, whereby the MMSCPSO algorithm reduced the active power losses at 18.681% then the PSO algorithm reduced the active power losses at 15.457%. Hence, the MMSCPSO could be a better solution for reactive power optimization in large-scale power systems.

Open Access Original Research Article

Cost Implications of Equipment Failures Using Life Cost Based Failure Modes and Effects Analysis (FMEA) on 365KVA Caterpillar Generator

Oghu Emughedi

Journal of Engineering Research and Reports, Page 43-51
DOI: 10.9734/jerr/2021/v20i917373

Equipment failures have implication on financial sustainability of the organization. This showcase the fact that equipment failures have cost implications and there is need to convert failures using Failure Modes and Effect Analysis, FMEA numerical analysis of 3parameters of severity, occurrence and detection that resulted to Risk Priority Number (RPN). The formula used in analyzing the results includes labour cost, material cost and opportunity cost. The labour cost is equals to the occurrence {[Delay Time.Labor of Operators]} plus [Fixing Time. Labor of Maintenance of personnel. Quantity] + [Detection Time. Labor rate no of Operators]}. Material Cost is equals to the occurrence x Quantity of parts to replace x Cost of Part. Opportunity Cost is equals to the Loss Time x Hourly Opportunity Cost. Loss Time is equals to the {Detection Time + Fixing Time + Delay Time}. This researched have proven that since installation of 365kva caterpillar generator in NNPC Lokoja that every time the generator failed to run, we can easily calculate the cost of labour, material to replace failed parts and opportunity cost of those idle times of failed production. Using the concept of FMEA, Failure Modes, Effects Analysis which produces Risk Priority Number (RPN) that is being computed by multiplying severity, occurrence and detection in which occurrence was gotten from equipment history card and logbooks since year 2005 when the installation of 365kva caterpillar generator was made till date. Likert questionnaires from industry experts were collated and Delphi method used to arrive accepted severity and detection to aid in the analysis. Millions of naira are being lost whenever equipment failures occurs and engineers from all fields, should always carry out root cause analysis whenever equipment failure occurs in order to prevent further occurrence.

Open Access Original Research Article

Comparison of Suction/Injection Effect on Flow, Heat and Mass Transfer in Porous Media Using a Combined Similarity-Numerical Solution

Falana Ayodeji, Babatope O. Pele, Abubakar A. Alao

Journal of Engineering Research and Reports, Page 52-58
DOI: 10.9734/jerr/2021/v20i917374

This investigation deals with a comparison of suction/injection effect on flow, heat and mass transfer in porous media using a combined similarity-numerical solution. With this method of transformation, the governing transport PDEs are transformed into ODE and then solved numerically. The study reveals that suction/injection effect is more pronounce on the velocity distribution of a creeping flow (Darcy flow). The Darcy-Forchheimer flow has the steepest velocity curves due to non-linearity and has higher skin friction, heat and mass transfer rate when compared to the other porous media investigated.

Open Access Original Research Article

Support Vector Machine Model for Predicting Gas Saturated and Undersaturated Crude Oil Viscosity of Niger Delta Oil Reservoir

Isemin Isemin, Akinsete Oluwatoyin, Akpabio Julius

Journal of Engineering Research and Reports, Page 59-65
DOI: 10.9734/jerr/2021/v20i917375

Oil viscosity is one of the most important physical and thermodynamic property used when considering reservoir simulation, production forecasting and enhanced oil recovery. Traditional experimental procedure is expensive and time consuming while correlations are replete however they are limited in precision, hence need for a new Machine Learning (ML) models to accurately quantify oil viscosity of Niger Delta crude oil.

This work presents use of ML model to predict gas-saturated and undersaturated oil viscosities. The ML used is the Support Vector Machine (SVM), it is applicable for linear and non-linear problems, the algorithm creates a hyperplane that separates data into two classes. The model was developed using data sets collected from the Niger Delta oil field. The data set was used to train, cross-validate, and test the models for reliability and accuracy. Correlation of Coefficient, Average Absolute Relative Error (AARE) and Root Mean Square Error (RMSE) were used to evaluate the developed model and compared with other correlations.

Result indicated that SVM model outperformed other empirical models revealing the accuracy and advantage SVM a ML technique over expensive empirical correlations.

Open Access Original Research Article

Performance of Active Clamp and Interleaved Active Clamp Fly back DC-DC Converters for PV Systems

Noorhan E. Elsobky, Yasmine Ashraf, Mostafa A. Hamouda, Mohamed Sabry, Sahar S. Kaddah, Basem M. Badr

Journal of Engineering Research and Reports, Page 66-79
DOI: 10.9734/jerr/2021/v20i917376

The Flyback converter topology is a well-known and widely used for AC-DC and DC-DC power converters that cover a broad-spectrum including switching power supplies, photovoltaic (PV) system, electric cars, and fuel cell-based generation systems, and among other applications. In this work, Active Clamp Flyback (ACF) and Interleaved Active Clamp (IACF) converters are designed and simulated for the use of DC-DC converters of PV system applications. Two control systems are used to control the output voltage of the DC-DC converters for various PV conditions, which are PID (proportional integral derivatives) and FLC (fuzzy logic controller). MATLAB/SIMULINK is used to model and simulate the proposed system, where the proposed control systems are developed to regulate the output voltage for the load requirements. The simulation results of the proposed PV systems indicate that the output voltage stabilizes effectively to the required voltage (24 V) for various loads/applications while the input voltage (output from the solar panel) to the converters is varying regrading to different sun radiation levels and other parameters. The efficiency of ACF and IACF converters are found to be 88% and 90%, respectively.

Open Access Original Research Article

Design of a Community-Based Anaerobic Digester for Sustainable Solid Waste Management in Ile-Oluji Ondo State Nigeria

R. I. Areola, O. O. Ipindola

Journal of Engineering Research and Reports, Page 80-91
DOI: 10.9734/jerr/2021/v20i917377

Aim: A Community-Based Anaerobic Digester was designed in this study for sustainable solid waste management in Ile-Oluji, Ondo state Nigeria.

Methodology: Waste samples were collected from selected households for a period of one month and the components and percentage composition were determined. Afterwards, the physico-chemical characteristics of the substrate was investigated and the result used to design a community-based anaerobic digester.

Results: The quantity, components and characteristics of waste generated was determined. The rate of waste generation was found to be 0.2kg/capita/day while the organic fraction of the total waste generated was found to be 55.7%. Physico-chemical characterization of the substrate was also investigated.  The pH was found to be 6.36 ± 0.18, while the alkalinity 692.81 ± 78.62.  The moisture content was found to be in the range of 71.20 ± 4.63%. Total solid was in the range 38.91 ± 5.25 while volatile solid was found to be 26.44 ± 2.83. carbon oxygen demand was found to be 834.33 ± 12.61, total phosphorus was in the range 4.20 ± 0.33. The Carbon on a dry weight basis was found to be in the range 60.41 ± 2.38, while nitrogen was found to be 4.79 ± 1.03. The C/N ration was found to be 21.61. The biogas yield ranged from 0 – 320 cm3 and 0 – 380cm3 per litre of substrate for biodegradable-only samples and biodegradable-cow dung samples respectively, for a forty days period of retention. The cylindrical dome type biogas digester was chosen for this study because of its simplicity in design and maintenance coupled with lower set up cost. The optimum volume of hydraulic chamber and gas storage chamber were designed to be the same as 850m3. Volume of fermentation chamber and sludge layer were calculated to be 2014m3 and 246m3 respectively, while the height and diameter of the fermentation chamber were 7m and 17m respectively.

Conclusion: Anaerobic digestion of the biodegradable fraction of solid waste is a viable alternative that government and non-government organizations can key into for the improvement of public health especially in developing countries. The standardization of digester design parameters may pose challenges because of varying climatic conditions and complex socio-economic factors across different geographical contexts. Solutions may have to be adapted and localized to achieve a sustainable world.

Open Access Original Research Article

Characterization and Application of Solitons in a High Nonlinearity Optical Link with Dense Wavelength Division Multiplexing (DWDM) and Ultra-Dense Wavelength Division Multiplexing (UDWDM) Technics

Aristide Mankiti Fati, Rostand Davy Martialy Loembe Souamy, Fraidy Ghislain Bouesse, . Nzonzolo, André Pasi Bengi Massata, Camille Nziengui Mabika, Badila Nkodia Chilperic

Journal of Engineering Research and Reports, Page 92-102
DOI: 10.9734/jerr/2021/v20i917378

The constantly growing needs in terms of speed and bandwidth, especially all services using data has become greedy. Today optical fiber is the medium of choice for many advantages over others channels. although the optical fiber has taken the label of transmission channels, we won’t be able to do without its nonlinear character and dispersions, which are part of the major problems during optical transmission. In this article, we are presenting the use of optical solitons in the fiber optic link, with a particular way; we have considered two kind of links, the underground one and the overhead one, in the first link, we have applied optical soliton in order to just take into account the optical Kerr effect. And for the overhead link, we can transmit for short distance by using the return to zero modulation’s format and the use of optical Erbium Doped Fiber Amplifiers (EDFA). The solitons which are the impulses, capable of propagating in the nonlinear optical fiber and dispersive without any distortion; to justify our hypothesis, we compare a dense wavelength division multiplexing (DWDM) without soliton and the dense wavelength division multiplexing with solitons; we notice that, the link with soliton is better than the first because the pulse keeps its shape from the source up to the destination, its eye diagram is opened which means there is no much noises. After the simulations in Matlab and optisystem software, we went to Congo telecom, to do our test with the optical time-domain reflectometer (OTDR), for both installations. From that study while transmitting over 100km it is better to use optical solitons with the high speed.

Open Access Original Research Article

Rainfall in Bangladesh

Debajani Chakraborty, Mst. Mahbuba Khatun, Iftekharul Alam

Journal of Engineering Research and Reports, Page 103-112
DOI: 10.9734/jerr/2021/v20i917379

Rainfall is the important climatic parameter on which the agriculture and economic condition of Bangladesh depends. For this reason, the scenario of rainfall throughout the country was illustrated briefly in this paper. Secondary data which were annual rainfall data of 34 stations were mainly used for this study, and these data were collected from BBS (Bangladesh Bureau of Statistics) between 2007 and 2019. The data were analyzed and visualized with the aid of Excel. However, the highest rainfall almost 5944 mm was recorded in Sylhet during the year 2017, and the lowest was 792 mm in Rajshahi in 2010. On the contrary, the minimum fluctuation of rainfall was observed in Mongla, whereas, the maximum fluctuation was found in Sylhet.

Open Access Original Research Article

Understanding Jig Alignment Error Occurrences for Substrate 1-Map Strips

Mariane A. Mendoza, Maria Virginia S. Buera, Frederick Ray I. Gomez, Allen Jay D. Kumawit

Journal of Engineering Research and Reports, Page 113-118
DOI: 10.9734/jerr/2021/v20i917380

Singulation is a process in a semiconductor industry where high dense strips were singulated into single units. Jig saw singulation was the updated technology where strips were seated and vacuumed on a rubber nest jig during singulation. Jig saw singulation is also practical for high volume manufacturing as it demands minimal indirect materials. To cut the strips, jig alignment with the strip was measured by the machine to ensure that the rubber nest jig will not be cut and damaged while the strip is being singulated. However, with the different upstream process that the strip undergone, machine prompt frequent jig alignment errors when the machine detected that the strip saw street has high displacement with the recorded alignment of the saw street of rubber nest jig. Through this study, the authors have driven to understand the jig alignment errors occurrences as well as the assistance that can be made for the strip to be processed. The authors also included the study of the risks that might be imposed on both rubber nest jig and the affected strips, as well as the recommendations when jig alignment errors were encountered.

Open Access Original Research Article

Viscoelastic Material Characterization: A Realistic Approach to Stress Analysis

Amor Zapanta, Jefferson Talledo

Journal of Engineering Research and Reports, Page 119-128
DOI: 10.9734/jerr/2021/v20i917381

This paper presents an advanced method in materials characterization for the mold compound material in semiconductor packages to build models that can technically explain the actual warpage or stress observations under different thermal conditions and time history. In the study, the mold compound material characterization was conducted using Dynamic Mechanical Analyzer (DMA) followed by curve fitting to obtain parameters for the computer modeling input requirement. Thermo-mechanical modeling using viscoelastic material properties was conducted on a bi-material test sample model. Results showed that the new characterized viscoelastic material properties exhibited dependence on time and temperature. Slow cool down from post mold cure (PMC) to room temperature resulted in lower warpage or stress. This observed rate dependent response was explained using viscoelastic material properties in contrast to the usual linear elastic material simplification. Thus, a realistic result from stress or warpage analysis could be achieved using viscoelastic material characterization.