EVALUATING WORD EMBEDDING MODELS FOR TRACEABILITY

ABSTRACT Traceability link recovery (TLR) is a software engineering activity that helps to ensure software quality and assists with keeping track of changes by establishing links between software artifacts that are a part of the software engineering process, such as requirements, use cases, source code, test cases, and documentation. Software requirement artifacts are typically written in natural language. An Information Retrieval process is frequently used in many software activities, including the TLR activity. Recently, Word Embedding (WE) techniques have been used in many natural language processing tasks as well as in TLR tasks. We investigate the effectiveness of WE techniques in conjunction with the ABC algorithm for automating the TLR process between requirements and source code. The ABC algorithm, which is a metaheuristic search Swarm Intelligence (SI) algorithm that simulates the behavior of honeybee swarms, is useful for solving multidimensional optimization problems. We use a modified ABC algorithm in which the initial population is generated randomly based on the document ID number within the document set boundaries. We use the algorithm to optimize the objective function and find the best links between the requirements and the source code. For our investigation we use three open source pretrained models: Word2Vec, GloVe, and FastText. We experiment with three objective functions that are optimized by the ABC algorithm to find the best possible links between the documents. Our experimentation with three datasets indicates that the three objective functions result in similar success rates. We use precision, recall, and the F1 measure to determine effectiveness for the TLR task. Our results show that the recall is higher than the precision and that the resulting F1 value does not indicate promise for combining word embedding, our three objective functions, and the modified ABC algorithm as a recommended approach for automating traceability links between requirements and source code

Experience, Education, and Entrepreneurial Success: A View from Bangladesh

This paper examines the impact of education on the age earnings profiles of self-employed Bangladeshi men, using data from a survey carried out by the first author in 2010. Its results strongly support the perception that educational attainment and on-the-job experience are strongly complementary rather than mutually substitutable in increasing the likelihood of achieving a high income level. Yet the high degree of earnings heterogeneity among well-educated respondents in the sample also indicates that academic excellence is a catalyst but not a guarantor for entrepreneurial success, and that levels of education that are formally equivalent may nevertheless have very different implications for the likelihood of prosperity in business

Millimeter Wave Systems for Airports and Short-Range Aviation Communications: A Survey of the Current Channel Models at mmWave Frequencies

Millimeter-wave (mmWave) communications will play a key role in enhancing the throughput, reliability, and security of next generation wireless networks. These advancements are achieved through the large bandwidth available in this band and through the use of highly directional links that will be used to overcome the large pathloss at these frequencies. Although the terrestrial application of mmWave systems is advancing at a rapid pace, the use of mmWave communication systems in aviation systems or airports is still in its infancy. This can be attributed to the challenges related to radio technology and lack of development, and characterization of mmWave wireless channels for the aviation field and the airport environment. Consequently, one of our goals is to develop methodologies that support mmWave air to ground links, and various links at airports, by applying new localization schemes that allow for application of highly directional links that can be deployed over longer distances despite the high path loss at mmWave frequencies. However, a very thorough understanding of the mmWave channel models are needed to enable such new applications. To this end, in this paper, we present a survey of the current channel models in the mmWave band. The 3-dimensional statistical channel model is also reviewed and its parameters and typical characteristics for this model are identified and computed through simulation for the Boise metropolitan area

Variable sampling interval run sum X‾ chart with estimated process parameters

The X‾ type control chart is often evaluated by assuming the process parameters are known. However, the exact values of process parameters are hardly known and thus Phase-I dataset is needed to estimate them. In this paper, the performance of the variable sampling interval run sum X‾ chart with estimated process parameters is evaluated by using the performance measure of the average of the average time to signal (AATS) and the optimal design of the proposed chart in minimizing the out-of-control AATS is developed. The performance measure of the standard deviation of the average time to signal (SDATS) is then used to identify the number of Phase-I samples (w) needed to have an in-control AATS performance close to its known process parameter case. Results show that large w is needed to minimize the performance gap between known and unknown process parameters cases of the VSI RS X‾ chart

Resistance Pattern of Levofloxacin against Uropathogens Causing Urinary Tract Infection in Selected Areas of Dhaka city, Bangladesh

A crucial public health problem in developing country like Bangladesh is resistance of antibiotics to different types of bacteria and the rates of these bacterial resistances are changing for various antibiotic therapy. Our aim was to assess the susceptible pattern of Levofloxacin a 3rd generation Quinolone antibiotic against uropathogens. A total of 12943 urine samples were collected in 2016 (Jan-Dec) and out of which 1236 (9.55%) were bacteriologically positive. Among the isolated uropathogens, 95.1% were gram negative and 4.9% gram positive organism. Male were found more prone to get UTI under 10 years and between 51-90 years of age and female were more affected in 10 to 50 years and over 90 years of age group. E. coli was the most prevalent (83.9%) isolate followed by Klebsiella spp. (6.7%), Staphylococcus aureus (2.6%), Pseudomonas spp. (2.2%), Enterococcus spp. (2.0%) and Proteus spp. (1.1%). The most predominant Levofloxacin sensitive organisms were found in male Enterobacter spp. (100%) and in female patients Serretia spp. (100%), Citrobacter spp. (100%) and Streptococcus Group B (100%). On the other hand the most predominant Levofloxacin resistant organisms were found in male and female both Acinetobacter spp. (100%). Around (61.7%) male and (46.9%) female were found resistant to E. coli. Keywords: Levofloxacin, Quinolone, UTI, Resistance, Uropathogen

Millimeter-Wave Channel Measurements in Airport Environment

The wide spectrum available at millimeter-wave (mmWave) bands promises very high data rates and has been proposed as an attractive solution to provide high-speed and reliable wireless communication. Further, there are various potential usages of mmWave technology in transportation, aviation, autonomous vehicles, robotics, etc. Specifically, it is anticipated that automation through this technology will affect and improve the operations in every phase in airport environments. Consequently, the extended autonomous capabilities at airports will generate and consume more information and increase the demand for robust data transfer, which requires larger data rates than ever before. Hence, mmWave frequency, due to its large available spectrum, can be utilized for achieving such larger data rates, specifically for short-range applications. However, utilization of this technology crucially depends on precise measurement, characterization, parameterization, and modeling of the wireless channel. Moreover, our literature survey has revealed a pressing need for channel models for new airport applications of mmWave frequency band. Therefore, in this dissertation, we empirically characterize mmWave channels in a variety of settings for airport communication systems. Several measurement campaigns and environment descriptions at several bands (60, 73, and 81 GHz) are presented. A combination of line-of-sight and non-line-of-sight measurements were taken in both indoor and outdoor settings at the Boise airport. Some measurements at these high frequencies were captured at Boise State University for comparison purposes. More specifically, we captured power delay profiles during the measurement campaign for the large-scale and small-scale fading analysis. For the large-scale fading effects, path loss models were computed from the power delay profiles at 60, 73, and 81 GHz, and some critical large-scale path loss parameters were extracted and analyzed. Moreover, we obtained mmWave outdoor small-scale fading statistics from 73 and 81 GHz channel measurement campaigns at Boise Airport. Wideband spatial fading measurements were made using a Gimbal attached with a linear track to move a receiver antenna for characterizing small-scale fading. Based upon our measurement data, we compared the receive signal amplitude with Rayleigh, Ricean, and log-normal fading models. In addition, we present the penetration, attenuation, and reflection characteristics of common building materials at these high-frequency bands. Measurements were taken for both wideband and narrowband signals to estimate attenuation at mmWave bands. These results are important to estimate coverage, interference analysis, and average error rate over a fading channel. Hence, they can aid researchers and system designers in the simulation and design of mmWave communication systems. Through extensive channel measurement campaigns and analysis, this dissertation contributes various insights to the field of wideband channel measurement and modeling in airport environments

Millimeter-Wave Propagation Channel Measurements at 73 GHz in Airport Environment

In this poster, based on the indoor and outdoor channel measurements at 73 GHz, a comprehensive large-scale fading path loss models are presented. The channel sounding measurements are carried out using a horn antenna at the transmitter (Tx) and receiver (Rx). The millimeter-wave propagation channel measurements campaigns were conducted at Boise Airport and Boise State University for both line-of-sight and none-line-of-sight scenarios. Subsequently, we developed the directional path loss models using close-in reference distance (CIM) and floating-intercept (FIM) methods. These approaches are applied to extract the large-scale channel parameters based on the empirical data. Path loss exponent (PLE) and shadow factor (σ) are estimated and compared to the free-space path loss parameters. Furthermore, the antenna height of the Rx is varied during taking channel measurements, and the path loss models are analyzed for the impact of the antenna heights. The results show that PLE extracted from the CIM model is close to the free-space path loss model