Engineering and Technology

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69 Gb/s DMT direct modulation of a Heterogeneously Integrated InP-on-Si DFB Laser
(In Optical Fiber Communication Conference, 2017) Rahim, Abdul; Abbasi, Amin; Sequeira André, Nuno; Katumba, Andrew; Louchet, Hadrien; Van Gasse, Kasper; Baets, Roel; Morthier, Geert; Roelkens, Gunther
Emerging applications such as high definition video streaming and cloud computing are the main drivers for the user-driven increase in the Internet traffic for the past few years. This has led to an increase in the processing capacity of the data centers demanding high-speed intra-datacenter communication links [1]. To address the expected growth of such short reach high speed links, the use of Wavelength Division Multiplexing (WDM) [2] and advanced modulation formats such as Quadrature Amplitude Modulation (QAM), multiband Carrierless Amplitude Phase Modulation (multi-CAP), Pulse Amplitude Modulation (PAM), and Discrete Multi-Tone (DMT) modulation [3,4] have been reported. Among these approaches, DMT has gained a lot of attention recently due to its ability to deliver 100G transmission using as low as ~20GHz optical devices [5]. Important considerations for such short reach communication links are low cost, small form factor and low power consumption. Silicon photonics is an emerging technology expected to deliver these attributes. Recently, data rates of 400 Gb/s by multiplexing 4 channels [5] and 0.88 Tb/s by multiplexing 10 channels [6] have been reported using silicon photonics. The power consumption of the optical frontend and footprint can be further reduced by implementing Directly Modulated Lasers (DMLs) on a heterogeneously integrated InP-on-Si platform [7]. Further more such lasers have been shown recently to have state-of-the-art modulation bandwidth performance [8]. In this paper we demonstrate single channel 69 Gb/s DMT modulation using a directly modulated heterogeneously integrated InP-on-Si DFB laser.
Acceptance and Use of Electronic Library Services in Ugandan Universities
(ACM/IEEE-CS joint conference, 2008) Tibenderana, Prisca K. G.; Ogao, Patrick J.
University libraries in Developing Countries (DCs), hampered by developmental problems, find it hard to provide electronic services. Donor communities have come in to bridge this technology gap by providing funds to university libraries for information technology infrastructure, enabling these university libraries to provide electronic library services to patrons. However, for these services to be utilized effectively, library endusers must accept and use them. To investigate this process in Uganda, this study modifies “The Unified Theory of Acceptance and Use of Technology” (UTAUT) by replacing “effort expectancy” and “voluntariness” with “relevancy”, “awareness” and “benefits” factors. In so doing, we developed the Service Oriented UTAUT (SOUTAUT) model whose dependent constructs predict 133% of the variances in user acceptance and use of e-library services. The study revealed that relevancy moderated by awareness plays a major factor in acceptance and use of e-library services in DCs.
An Accurate Indoor User Position Estimator For Multiple Anchor UWB Localization
(IEEE, 2020) Poulose, Alwin; Emeršic, Žiga; Eyobu, Odongo Steven; Seog Han, Dong
UWB-based positioning systems have been proven to provide a significant high level of accuracy hence offering a huge potential for a variety of indoor applications. However, the major challenges related to UWB localization are multipath effects, excess delay, clock drift, signal interferences and system computational time to estimate the user position. To compensate for these challenges, the UWB system uses multiple anchors in the experiment area and this gives accurate position results with minimum localization errors. However, the use of multiple anchors in the UWB system means processing large amounts of data in the system controller for localization, which leads to high computational time to estimate the current user position. To reduce the complexity of the UWB systems, we propose a position estimator for multiple anchor indoor localization, which uses the extended Kalman filter (EKF). The proposed UWB-EKF estimator was mathematically analysed and the simulation results were compared with classical localization algorithms considering the mean localization errors. In the simulation, three classical localization algorithms: linearized least square estimation (LLSE), weighted centroid estimation (WCE) and maximum likelihood estimation (MLE) were used for performance comparison. Thorough extensive simulation done in this study achieves results which demonstrate the effectiveness of the proposed UWB-EKF estimator for multiple anchor UWB indoor localization.
Adding Value Every Sprint: A Case Study on Large-Scale Continuous Requirements Engineering
(WS on Continuous Requirements Engineering, 2017) Kasauli, Rashidah; Knauss, Eric; Nilsson, Agneta; Klug, Sara
Agile development practices, such as continuous integration and continuous delivery, promise value through shorter time to market and increased exibility. While these practices have been widely adopted in small-scale, they have shown to be challenging to adopt in large-scale, system development. This is often due to a distance between customer and developer in large scale systems, and the need to break down value from the whole system into manageable parts. The notion of value is fundamental for agile methods, especially for practices such as continuous delivery to the customer. However, how value should be handled in development practices is not clearly understood. In this paper, we investigate how the notion of adding value in every sprint has been perceived in a large-scale system development. Based on an exploratory qualitative case study, the outcome shows that it is perceived bene cial by practitioners although it comes at a price and challenges exist.
ADSMS: Anomaly Detection Scheme for Mitigating Sink Hole Attack in Wireless Sensor Network
(IEEE, 2017) Yasin, N. Mohammaed; Balaji, N.; Sambasivam, G.; Basha, M. S. Saleem; Sujatha, P.
In past years, mobile ad hoc networks (MANETs) widespread use in many applications, including for some mission-critical applications, and has become one of the major concerns such as security MANETs. MANETs due to some unique characteristics, prevention methods are not alone enough to protect them need; Therefore, the detection is possible for an attacker to breach system security, such as the need to add another before. In general, traditional wireless networks, intrusion detection techniques are not well suited for MANETs. In this case, to protect it from attacks MANETs is important to develop more efficient methods of intrusion detection. With improvements in technology and cutting hardware costs, we MANETs expanding into industrial applications are also witnessing a current trend. To cope with such a trend and we believe strongly that it was important for its potential security issues. In this paper, we propose new intrusion detection and specially designed MANETs Improved Acceptance acknowledgment (EAACK) to activate the digital signature system. Compared to contemporary approaches, while not greatly affect network shows EAACK certain conditions demonstrates the high detection rates of malicious behaviour
An Algorithm for Geo-Spatial Objects Adjustment
(Advances in Geomatics Research (, 2015) Wadembere, Ismail; Ogao, Patrick
GIS practitioners always integrate geo-spatial data from different sources using map-overlay operations in order to make decisions and solve queries that deal with multiple layers. But they are always faced with openings and overlaps among objects that form features in thematically same datasets resulting into slivers (unwanted small objects) and danglings (unwanted intersections, polylines, and end points). Most GIS users end up running clean and build algorithms that just remove unwanted objects but not achieving perfect merging originally intended with main reason being lack of geometrical object based algorithm that can be used to update and adjust spatial objects to eliminate discrepancies caused by geometry differences between features of thematically similar data. We present an algorithm for manipulating geometries of geospatial objects that make up datasets basing on spatial points as the simplest geometrical primitive. Our approach makes it possible to represent high level spatial geometrical shapes using points and allows for more comprehensive handling of all shapes still maintaining the simplicity of working with the point primitive. Representation of spatial geometry shapes comprising of spatial points, polylines, and polygons using spatial point primitive geometry is achieved by scanning all the spatial dataset, observing the different geometry shapes and topology that exist, then representation all shapes using points and primary attribute in form of text. The algorithm carries out shape transformation of objects so that all openings and overlaps between objects making up dataset are eliminated so that geo-processing, modeling, and analysis utilize the properly integrated datasets. The algorithm can be applied in spatial data management like geometrical alignment and sharing environments like spatial data infrastructure.
Analyzing the Eclipse API Usage: Putting the Developer in the Loop
(IEEE, 2013) Businge, John; Serebrenik, Alexander; van den Brand, Mark
Eclipse guidelines distinguish between two types of interfaces provided to third-party developers, i.e., APIs and non-APIs. APIs are stable and supported, while non-APIs are unstable, unsupported and discouraged as they are subject to arbitrary change or removal without notice. In our previous work, we found that despite the discouragement of Eclipse, the use of non-APIs in Eclipse third-party plug-ins (ETPs) is not uncommon. Furthermore, we found that these non-APIs are the main cause of ETP incompatibilities in forthcoming releases of the Eclipse. In the current work we conducted a survey aiming at understanding why do the ETP developers use non-APIs. We have observed that developers with a level of education of up to master degree have a tendency not to read product manuals/ guidelines. Furthermore, while for less experienced developers instability of the non-APIs overshadows their benefits, more experienced developers prefer to enjoy the benefits of non-APIs despite the instability problem. Finally, we have observed that there are no significant differences between Open Source and commercial Eclipse products in terms of awareness of Eclipse guidelines and interfaces, Eclipse product size and updating of Eclipse product in the new SDK releases.
ANN-based Stride Detection Us ing Smartphones for Pedestrian Dead Reckoning
(IEEE, 2018) Kim, Youngwoo; Eyobu, Odongo Steven; Seog Han, Dong
Position awareness is a very important issue for internet of thing (IoT) applications using smartphones. Pedestrian dead reckoning (PDR) is one of the methods used to estimate a user’s indoor position. The accuracy of a stride detection is very important to guarantee the estimation accuracy of the user location. This paper proposes an algorithm to detect the stride using acceleration spectrogram feature by utilizing the accelerometer in a smartphone. An artificial neural network (ANN) technology is applied to detect the stride. The proposed algorithm has an accuracy of 97.7% for stride detection.
Application of Response Surface Methodology for Optimizing Tensile Strength of Rice Husk Fiber-Reinforced Polylactic Acid Composites
(MDPI, 2021) Yiga, Vianney Andrew; Lubwama, Michael; Olupot, Peter Wilberforce
Filler/fiber loading and surface modification significantly influence tensile properties of natural fiber-reinforced plastic composites. It is therefore pertinent that they are suitably selected in order to yield the optimum tensile properties. Fiber-reinforced PLA composites were prepared us-ing compression molding with Box-Behnken Design experimental design approach. Factors, namely clay filler loading (1−5 wt.%), rice husk fiber loading (10−30 wt.%), alkali concentration (0−4 wt.%), rice husk variety (K85, K98) and alkali type (NaOH, Mg(OH)2) were varied. ANOVA determined significance of the factors affecting composites’ tensile strength. ANOVA results revealed the re-duced cubic model as best fit for tensile strength response. The desirability function revealed that variable values leading to optimum tensile strength (33.67 MPa) were 4.97 wt.%, 11.16 wt.% and 3.99 wt.% for filler loading, fiber loading and alkali concentration, respectively.
Approaches Towards Effective Knowledge Management for Small and Medium Enterprises in Developing Countries - Uganda
(IIMC International Information Management Corporation, 2009) Habinka, Annabella; Sol, Henk; Baryamureeba, Venansius
In developing countries, many Small and Medium Enterprises (SMEs) collapse due to complex factors. Knowledge shortage and fragmented information are their key challenges as a result of obsolete technology and exposure. However, the Government of Uganda plans to establish nationwide knowledge service centres in its Vision 2035 [9]. Viable solutions are at stake for developing countries. However, to enable them leap frog into the future, ICT is the remedy for knowledge sharing. SME survival is determined by the amount of knowledge they have and how they manage it in decision making. This paper promotes the studio based approach as a practical solution to SMEs asymmetric knowledge sharing. The studio will provide decision enhanced services to SME stakeholders and supplement techno-centric, social-cultural-centric and access-centric approaches. This paper aims at providing a theoretical backup for studio usage as a feasible solution for SMEs in developing countries.
Automated image-based diagnosis of cowpea diseases
(AGILE, 2018) Nsumba, Solomon; Mwebaze, Ernest; Bagarukayo, Emily; Maiga, Gilbert
Cowpea is the third most important legume food crop in Uganda with the eastern and northern regions accounting for most of the production in the country. However, it is vulnerable to virus and fungal diseases, which threaten to destabilize food security in sub-Saharan Africa. Unique methods of cowpea disease detection are needed to support improved control which will prevent this crisis. In this paper, we discuss automated disease detection model for cowpea based on deep neural network computational techniques that can be used by non-experts and smallholder farmers to do the field-based diagnosis of cowpea diseases. Image recognition offers both a cost-effective and scalable technology for disease detection. New transfer learning methods offer an avenue for this technology to be easily deployed on mobile devices. Using a dataset of cowpea disease images taken in the field in Uganda, we applied transfer learning to train a deep convolutional neural network to identify three cowpea diseases and to identify healthy plants as well. The best-trained model accuracies were 98% for healthy, 95% for powdery mildew, 98% for cercospora, and 96% for the mosaic virus. The best model achieved an overall accuracy of 93% for data not used in the training process. Our results show that the transfer learning approach for image recognition of field images offers a fast, affordable, and easily deployable strategy for digital plant disease detection.
A Bird’s Eye View of a Sustainable Learning Game Design
(Springer, Cham., 2021) Boogere, James; Oyo, Benedict; Eilu, Emmanuel; Birevu Muyinda, Paul
We empirically explore learning games with an aim of empowering learners’ lifelong learning skills to enable them deal with complex situations sustainably. Learning is better by doing and the relation between learning and fun in games is essentially much deeper. It is also important for the players to clearly know the game system, which involves goals, entities and rules, in order to improve the vital individual social skills required to succeed. This chapter presents learning designs as a major determinant of motivation towards meaningful learning and challenge learners through continual provision of new aspects to learn, discover and develop oneself. Prior consequences designate that holistic learning game practices are more intense in a home compared to a school context. Moreover, the overall influence of context on perceived learning is significantly smaller than that of other experimental factors such as identification and enjoyment.
Blockchain-Oriented Software Variant Forks: A Preliminary Study
(IEEE, 2022) Rocha, Henrique; Businge, John
In collaborative social development platforms such as GitHub, forking a repository is a common activity. A variant fork wants to split the development from the original repository and grow towards a different direction. In this preliminary exploratory research, we analyze the possible reasons for creating a variant fork in blockchain-oriented software. By collecting repositories in GitHub, we created a dataset with repositories and their variants, from which we manually analyzed 86 variants. Based on the variants we studied, the main reason to create a variant in blockchain-oriented software is to support a different blockchain platform (65%).
Can We Find Stable Alternatives For Unstable Eclipse Interfaces?
(IEEE, 2016) Kawuma, Simon; Businge, John
The Eclipse framework is a popular and widely adopted framework that has been evolving for over a decade. Like many other evolving software systems, the Eclipse framework provides both stable and supported interfaces (APIs) and unstable, discouraged, and unsupported interfaces (non- APIs). However, despite being discouraged by Eclipse, the usage of bad interfaces is not uncommon. Our previous research has confirmed t hat a s E clipse s tates, i ndeed A PIs a re stable while non-APIs are unstable. Applications using non-APIs face compatibility challenges in new Eclipse releases. Furthermore, our previous studies further revealed that the reason why application developers use the unstable interfaces is because they cannot find s table i nterfaces w ith t he f unctionality t hat they require. Moreover, in a study we conducted, Eclipse application developers stated that they manually find t he functionality from Eclipse. Eclipse being a very large complex software system with a large number of committers, we hypothesize that as developers manually search for the functionality they they require, it is possible that they miss stable interfaces offering the same functionality. To this end, using code clone detection techniques, we analyzed 18 major releases of Eclipse for possible clones. Our findings a re t hree fold: i ) we discover that indeed there exist clones in Eclipse, ii) we also discovered that some of the identified c lones o riginate f rom different Eclipse projects, iii) our findings r eveal t hat t here i s no significant number of APIs (less than 1%) offering the same or similar functionality as the non-APIs in all Eclipse releases we studied. This reveals that there are very few syntactic clones between API and non-API, thus developers were forced to either use non-API or find a n API t hat e xists, t hat i s similar in functionality, but not in syntax.
Catching up with Method and Process Practice: An Industry-Informed Baseline for Researchers
(IEEE, 2019) Klunder, Jil; Hebig, Regina; Tell, Paolo; Kuhrmann, Marco; Nakatumba-Nabende, Joyce; Heldal, Rogardt; Prikladnickixv, Rafael; Tuzunxvi, Eray; Pfahlxvii, Dietmar; Schneider, Kurt; MacDonellxviii, Stephen G.
Software development methods are usually not applied by the book. Companies are under pressure to continuously deploy software products that meet market needs and stakeholders’ requests. To implement efficient and effective development processes, companies utilize multiple frameworks, methods and practices, and combine these into hybrid methods. A common combination contains a rich management framework to organize and steer projects complemented with a number of smaller practices providing the development teams with tools to complete their tasks. In this paper, based on 732 data points collected through an international survey, we study the software development process use in practice. Our results show that 76.8% of the companies implement hybrid methods. Company size as well as the strategy in devising and evolving hybrid methods affect the suitability of the chosen process to reach company or project goals. Our findings show that companies that combine planned improvement programs with process evolution can increase their process’ suitability by up to 5%.
Challenges of Aligning Requirements Engineering and System Testing in Large-Scale Agile: A Multiple Case Study
(IEEE, 2017) Gomes de Oliveira Neto, Francisco; Horkoff, Jennifer; Knauss, Eric; Kasauli, Rashidah; Liebel, Grischa
As agile methods become more pervasive, agile practices are applied to more large-scale systems with a scope that goes beyond pure software. The expansion of agile in these contexts provides benefits, but creates new challenges. Widespread use of agile has changed the way we must think about practices both in Requirements Engineering (RE) and in System Testing (ST). Our experience shows that many challenges in the application of large-scale agile development relate to either RE or ST, and in particular to the alignment between these areas. In this paper we present large-scale agile-related challenges from a multiple case study which relate to REST alignment. We map our challenges to an existing framework for REST alignment, and make an initial attempt to suggest agile RE practices from the literature which may alleviate these challenges. Our results show that the interviewed companies need to first adopt more agile RE practices to enhance REST alignment and then leverage agile testing. Future work will look more towards evaluating these best practices.
Classification and Measure of Quantitative Difference between Polyester and Cotton Fabrics Based on Sensory Analysis
(FLINS, 2016) Kamalha, Edwin; Koehl, Ludovic; Campagne, Christine
In this study we compare cotton and polyester (Polyethylene terephthalate) (PET) sensory attributes, as a precursor for sensory modification of polyester, for cotton replacement. We systematically identify the key sensory attributes that distinguish cotton from polyester fabrics. Rank Aggregation, Principal Component Analysis (PCA), Agglomerative Hierarchical Clustering (AHC), and the measure of distances are used to process elicited data.
Classifying Desirable Features of Software Visualization Tools for Corrective Maintenance
(ACM symposium on Software visualization, 2008) Sensalire, Mariam; Ogao, Patrick; Telea, Alexandru
We provide an evaluation of 15 software visualization tools applicable to corrective maintenance. The tasks supported as well as the techniques used are presented and graded based on the support level. By analyzing user acceptation of current tools, we aim to help developers to select what to consider, avoid or improve in their next releases. Tool users can also recognize what to broadly expect (and what not) from such tools, thereby supporting an informed choice for the tools evaluated here and for similar tools.
Clone-Based Variability Management in the Android Ecosystem
(IEEE, 2018) Businge, John; Openja, Moses; Nadi, Sarah; Bainomugisha, Engineer; Berger, Thorsten
Abstract—Mobile app developers often need to create variants to account for different customer segments, payment models or functionalities. A common strategy is to clone (or fork) an existing app and then adapt it to new requirements. This form of reuse has been enhanced with the advent of social-coding platforms such as Github, cultivating a more systematic reuse. Different facilities, such as forks, pull requests, and cross-project traceability support clone-based development. Unfortunately, even though, many apps are known to be maintained in many variants, little is known about how practitioners manage variants of mobile apps. We present a study that explores clone-based reuse practices for open-source Android apps. We identified and analyzed families of apps that are maintained together and that exist both on the official app store (Google Play) as well as on Github, allowing us to analyze reuse practices in depth. We mined both repositories to identify app families and to study their characteristics, including their variabilities as well as codepropagation practices and maintainer relationships. We found that, indeed, app families exist and that forked app variants fall into the following categories: (i) re-branding and simple customizations, (ii) feature extension, (iii) supporting of the mainline app, and (iv) implementation of different, but related features. Other notable characteristic of the app families we discovered include: (i) 73% of the app families did not perform any form of code propagation, and (ii) 74% of the app families we studied do not have common maintainers.
Co-evolution of the Eclipse SDK Framework and its Third-party Plug-ins
(IEEE, 2013) Businge, John
Today, when constructing a new software system, many developers build their systems on top of frameworks. Eclipse framework is one such popular and widely adopted framework that has been evolving for over a decade. Like many other evolving software systems, the Eclipse SDK framework has both stable and supported APIs (good interfaces) and unstable, discouraged and unsupported non-APIs (bad interfaces). However, despite being discouraged by Eclipse, in our experience, the usage of bad interfaces is not uncommon. In this thesis, by means of a series of empirical studies, we quantify/qualify some the challenges faced by Eclipse thirdparty plug-in developers in using the interfaces provided by the Eclipse SDK framework. Furthermore, we propose solutions to the identified challenges, like changes in development strategy to both interface providers and interface users. In particular, the lessons learned from this study can provide valuable information in particular to the interface providers, i.e., Eclipse SDK developers, and the interface uses, i.e., ETP developers, in co-evolving the Eclipse framework. In general, the lessons learned can be transferable to other framework ecosystem.

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