arXiv subjects

Jaderick P. Pabico

Publications and source records attributed to Jaderick P. Pabico.

At least 19 recordsLinked to original sources

arXiv2017

Insertion Sort with Self-reproducing Comparator P System

We present in this paper a self-reproducing comparator P~system that simulates insertion sort. The comparator $Π_c$ is a degree-2 membrane and structured as $μ= [_{h_0} [_{h_1}]_{h_1} [_{h_2}]_{h_2} ]_{h_0}$. A maximizing $Π_c$ compares two multisets $a$ and $b$ where $\min(|a|,|b|)$ is stored in compartment $h_1$ while $\max(|a|,|b|)$ is stored in compartment $h_2$. A conditional reproduction rule triggers $Π_c$ to clone itself out via compartment division followed by endocytosis of the cloned compartment. We present the process of sorting as a collection of transactions implemented in hierarchical levels where each level has different concurrent or serialized steps.

cs.ET↗

arXiv2016

Improved Sampling Techniques for Learning an Imbalanced Data Set

This paper presents the performance of a classifier built using the stackingC algorithm in nine different data sets. Each data set is generated using a sampling technique applied on the original imbalanced data set. Five new sampling techniques are proposed in this paper (i.e., SMOTERandRep, Lax Random Oversampling, Lax Random Undersampling, Combined-Lax Random Oversampling Undersampling, and Combined-Lax Random Undersampling Oversampling) that were based on the three sampling techniques (i.e., Random Undersampling, Random Oversampling, and Synthetic Minority Oversampling Technique) usually used as solutions in imbalance learning. The metrics used to evaluate the classifier's performance were F-measure and G-mean. F-measure determines the performance of the classifier for every class, while G-mean measures the overall performance of the classifier. The results using F-measure showed that for the data without a sampling technique, the classifier's performance is good only for the majority class. It also showed that among the eight sampling techniques, RU and LRU have the worst performance while other techniques (i.e., RO, C-LRUO and C-LROU) performed well only on some classes. The best performing techniques in all data sets were SMOTE, SMOTERandRep, and LRO having the lowest F-measure values between 0.5 and 0.65. The results using G-mean showed that the oversampling technique that attained the highest G-mean value is LRO (0.86), next is C-LROU (0.85), then SMOTE (0.84) and finally is SMOTERandRep (0.83). Combining the result of the two metrics (F-measure and G-mean), only the three sampling techniques are considered as good performing (i.e., LRO, SMOTE, and SMOTERandRep).

cs.LG↗

arXiv2015

Social Loafing Among Members of Undergraduate Software Engineering Groups: Persistence of Perception Seven Years After

We surveyed 169 undergraduate students who are enrolled in various courses. They were members of software engineering groups formed to solve various real-world computational problems by implementing software projects as part of the requirements of the course. This time, our analysis show that task visibility is negatively associated with social loafing while contributions, dominance, aggression and sucker effect are positively correlated. We further found out that perception of social loafing exists and still persists among members of computer programming groups. Compared to our 2008 analysis, we provide in this paper detailed analysis based on demographic parameters such as gender, course taken, age group, type of residence (urban or rural), and region of residence. The implication of this result is that aside from the usual problems that an instructor faces in teaching software engineering-related courses, the presence of social loafing also adds to the impediment of teaching effectiveness. Thus, it is imperative that instructors and course designers consider the implications associated with social loafing when designing group projects.

cs.CY↗

arXiv2015

On Gobbledygook and Mood of the Philippine Senate: An Exploratory Study on the Readability and Sentiment of Selected Philippine Senators' Microposts

This paper presents the findings of a readability assessment and sentiment analysis of selected six Philippine senators' microposts over the popular Twitter microblog. Using the Simple Measure of Gobbledygook (SMOG), tweets of Senators Cayetano, Defensor-Santiago, Pangilinan, Marcos, Guingona, and Escudero were assessed. A sentiment analysis was also done to determine the polarity of the senators' respective microposts. Results showed that on the average, the six senators are tweeting at an eight to ten SMOG level. This means that, at least a sixth grader will be able to understand the senators' tweets. Moreover, their tweets are mostly neutral and their sentiments vary in unison at some period of time. This could mean that a senator's tweet sentiment is affected by specific Philippine-based events.

cs.CL↗

arXiv2015

The Interactive Effects of Operators and Parameters to GA Performance Under Different Problem Sizes

The complex effect of genetic algorithm's (GA) operators and parameters to its performance has been studied extensively by researchers in the past but none studied their interactive effects while the GA is under different problem sizes. In this paper, We present the use of experimental model (1)~to investigate whether the genetic operators and their parameters interact to affect the offline performance of GA, (2)~to find what combination of genetic operators and parameter settings will provide the optimum performance for GA, and (3)~to investigate whether these operator-parameter combination is dependent on the problem size. We designed a GA to optimize a family of traveling salesman problems (TSP), with their optimal solutions known for convenient benchmarking. Our GA was set to use different algorithms in simulating selection ($Ω_s$), different algorithms ($Ω_c$) and parameters ($p_c$) in simulating crossover, and different parameters ($p_m$) in simulating mutation. We used several $n$-city TSPs ($n=\{5, 7, 10, 100, 1000\}$) to represent the different problem sizes (i.e., size of the resulting search space as represented by GA schemata). Using analysis of variance of 3-factor factorial experiments, we found out that GA performance is affected by $Ω_s$ at small problem size (5-city TSP) where the algorithm Partially Matched Crossover significantly outperforms Cycle Crossover at $95\%$ confidence level.

cs.NE↗

arXiv2015

Perceived Social Loafing in Undergraduate Software Engineering Teams

We surveyed 237 undergraduate students who are enrolled in various subjects and are members of software engineering teams. Their being a member in a team is part of the requirements of the course. We found that each of task visibility, distributive justice, and intrinsic task involvement were negatively associated with social loafing. We also found out that dominance, aggression and sucker effect each were positively correlated with social loafing. We further found out that perception of social loafing exists among members of software engineering teams.

cs.CY↗

arXiv2015

Inferences in a Virtual Community: Demography, User Preferences, and Network Topology

This paper presents a computational procedure for extracting demography data, mining patterns of human preferences, and measuring the topology of a virtual network. The network was created from the personal and relationships data of an online Internet-based community, where persons are considered nodes in the network, and relationships between persons are considered edges. A community of Friendster users whose listed hometown is Los Baños, Laguna was used as a test bed for the methodology. The method was able to provide the following demographic, preferential, and topological results about the test bed: (1) There are more female users (52.34\%) than male (47.66\%); (2) Homophily (i.e., birds-of-a-feather adage) is observed in the preferences of users with respect to age levels, such that they are strongly biased towards being friends with users of a similar age; (3) There is heterophily in gender preference such that friendship among users of the opposite gender occurs more often. (4) It exhibits a small-world characteristic with an average path length of 4.5 (maximum=12) among connected users, shorter than the well-known {\em six degrees of separation}~\cite{travers69}; And (5) The network exhibits a scale-free characteristics with heavily-tailed power-law distribution (with the power $λ= -1.02$ and $R^2 = 0.84$) suggesting the presence of many users acting as the network hubs. The methodology was successful in providing important data from a virtual community which can be used by several researchers in the fields of statistics, mathematics, physics, social sciences, and computer science.

cs.SI↗

arXiv2015

A Neural Prototype for a Virtual Chemical Spectrophotometer

A virtual chemical spectrophotometer for the simultaneous analysis of nickel (Ni) and cobalt (Co) was developed based on an artificial neural network (ANN). The developed ANN correlates the respective concentrations of Co and Ni given the absorbance profile of a Co-Ni mixture based on the Beer's Law. The virtual chemical spectrometer was trained using a 3-layer jump connection neural network model (NNM) with 126 input nodes corresponding to the 126 absorbance readings from 350 nm to 600 nm, 70 nodes in the hidden layer using a logistic activation function, and 2 nodes in the output layer with a logistic function. Test result shows that the NNM has correlation coefficients of 0.9953 and 0.9922 when predicting [Co] and [Ni], respectively. We observed, however, that the NNM has a duality property and that there exists a real-world practical application in solving the dual problem: Predict the Co-Ni mixture's absorbance profile given [Co] and [Ni]. It turns out that the dual problem is much harder to solve because the intended output has a much bigger cardinality than that of the input. Thus, we trained the dual ANN, a 3-layer jump connection nets with 2 input nodes corresponding to [Co] and [Ni], 70-logistic-activated nodes in the hidden layer, and 126 output nodes corresponding to the 126 absorbance readings from 250 nm to 600 nm. Test result shows that the dual NNM has correlation coefficients that range from 0.9050 through 0.9980 at 356 nm through 578 nm with the maximum coefficient observed at 480 nm. This means that the dual ANN can be used to predict the absorbance profile given the respective Co-Ni concentrations which can be of importance in creating academic models for a virtual chemical spectrophotometer.

cs.NE↗

arXiv2015

Capturing the Dynamics of Pedestrian Traffic Using a Machine Vision System

We developed a machine vision system to automatically capture the dynamics of pedestrians under four different traffic scenarios. By considering the overhead view of each pedestrian as a digital object, the system processes the image sequences to track the pedestrians. Considering the perspective effect of the camera lens and the projected area of the hallway at the top-view scene, the distance of each tracked object from its original position to its current position is approximated every video frame. Using the approximated distance and the video frame rate (30 frames per second), the respective velocity and acceleration of each tracked object are later derived. The quantified motion characteristics of the pedestrians are displayed by the system through 2-dimensional graphs of the kinematics of motion. The system also outputs video images of the pedestrians with superimposed markers for tracking. These visual markers were used to visually describe and quantify the behavior of the pedestrians under different traffic scenarios.

cs.CV↗

arXiv2015

Authorship Patterns in Computer Science Research in the Philippines

We studied patterns of authorship in computer science~(CS) research in the Philippines by using data mining and graph theory techniques on archives of scientific papers presented in the Philippine Computer Science Congresses from 2000 to 2010 involving 326~papers written by 605~authors. We inferred from these archives various graphs namely, a paper--author bipartite graph, a co-authorship graph, and two mixing graphs. Our results show that the scientific articles by Filipino computer scientists were generated at a rate of 33~papers per year, while the papers were written by an average of 2.64~authors (maximum=13). The frequency distribution of the number of authors per paper follows a power-law with a power of $φ=-2.04$ ($R^2=0.71$). The number of Filipino CS researchers increases at an annual rate of 60~new scientists. The researchers have written an average of 1.42~papers (maximum=20) and have collaborated with 3.70~other computer scientists (maximum=54). The frequency distribution of the number of papers per author follows a power law with $φ=-1.88$ ($R^2=0.83$). This distribution closely agrees with Lotka's {\em law of scientific productivity} having $φ\approx -2$. The number of co-authors per author also follows a power-law with $φ=-1.65$ ($R^2=0.80$). These results suggest that most CS~papers in the country were written by scientists who prefer to work alone or at most in small groups. These also suggest that few papers were written by scientists who were involved in large collaboration efforts. The productivity of the Philippines' CS researchers, as measured by their number of papers, is positively correlated with their participation in collaborative research efforts, as measured by their number of co-authors (Pearson $r=0.7425$).

cs.DL↗

arXiv2015

Information Spread Over an Internet-mediated Social Network: Phases, Speed, Width, and Effects of Promotion

In this study, we looked at the effect of promotion in the speed and width of spread of information on the Internet by tracking the diffusion of news articles over a social network. Speed of spread means the number of readers that the news has reached in a given time, while width of spread means how far the story has travelled from the news originator within the social network. After analyzing six stories in a 30-hour time span, we found out that the lifetime of a story's popularity among the members of the social network has three phases: Expansion, Front-page, and Saturation. Expansion phase starts when a story is published and the article spreads from a source node to nodes within a connected component of the social network. Front-page phase happens when a news aggregator promotes the story in its front page resulting to the story's faster rate of spread among the connected nodes while at the same time spreading the article to nodes outside the original connected component of the social network. Saturation phase is when the story ages and its rate of spread within the social network slows down, suggesting popularity saturation among the nodes. Within these three phases, we observed minimal changes on the width of information spread as suggested by relatively low increase of the width of the spread's diameter within the social network. We see that this paper provides the various stakeholders a first-hand empirical data for modeling, designing, and improving the current web-based services, specifically the IT educators for designing and improving academic curricula, and for improving the current web-enabled deployment of knowledge and online evaluation of skills.

cs.SI↗

arXiv2015

Towards Input Device Satisfaction Through Hand Anthropometry

We collected the hand anthropometric data of 91 respondents to come up with a Filipino-based measurement to determine the suitability of an input device for a digital equipment, the standard PC keyboard. For correlation purposes, we also collected other relevant information like age, height, province of origin, and gender, among others. We computed the percentiles for each finger to classify various finger dimensions and identify length-specific anthropometric cut-points. We compared the percentiles of each finger dimension against the actual length of the longest key combinations when correct finger placement is used for typing, to determine whether the standard PC keyboard is fit for use by our sampled population. Our analysis shows that the members of the population with hand dimensions at extended position below 75th percentile and at 99th percentile are the ones who would most likely not reach the longest key combination for the left and the right hands, respectively. Using machine vision and image processing techniques, we automated the anthropometric process and compared the accuracy of its measurements to that of manual process'. We compared the measurement generated by our automated anthropometric process with the measurements using the manual one and we found out that they have a very minimal absolute difference. The data collected from this study could be used in other studies such as determining a good design for mobile and other handheld devices, or input devices other than keyboard. The automated method that we developed could be used to easily measure hand dimensions given a digital image of the hand and could be extended for measuring the entire human body for various other applications.

cs.CY↗

arXiv2015

A System for Sensing Human Sentiments to Augment a Model for Predicting Rare Lake Events

Fish kill events (FKE) in the caldera lake of Taal occur rarely (only 0.5\% in the last 10 years) but each event has a long-term effect on the environmental health of the lake ecosystem, as well as a devastating effect on the financial and emotional aspects of the residents whose livelihood rely on aquaculture farming. Predicting with high accuracy when within seven days and where on the vast expanse of the lake will FKEs strike will be a very important early warning tool for the lake's aquaculture industry. Mathematical models to predict the occurrences of FKEs developed by several studies done in the past use as predictors the physico-chemical characteristics of the lake water, as well as the meteorological parameters above it. Some of the models, however, did not provide acceptable predictive accuracy and enough early warning because they were developed with unbalanced binary data set, i.e., characterized by dense negative examples (no FKE) and highly sparse positive examples (with FKE). Other models require setting up an expensive sensor network to measure the water parameters not only at the surface but also at several depths. Presented in this paper is a system for capturing, measuring, and visualizing the contextual sentiment polarity (CSP) of dated and geolocated social media microposts of residents within 10km radius of the Taal Volcano crater ($14^\circ$N, $121^\circ$E). High frequency negative CSP co-occur with FKE for two occasions making human expressions a viable non-physical sensors for impending FKE to augment existing mathematical models.

cs.SI↗

arXiv2015

Automatic Identification of Animal Breeds and Species Using Bioacoustics and Artificial Neural Networks

In this research endeavor, it was hypothesized that the sound produced by animals during their vocalizations can be used as identifiers of the animal breed or species even if they sound the same to unaided human ear. To test this hypothesis, three artificial neural networks (ANNs) were developed using bioacoustics properties as inputs for the respective automatic identification of 13 bird species, eight dog breeds, and 11 frog species. Recorded vocalizations of these animals were collected and processed using several known signal processing techniques to convert the respective sounds into computable bioacoustics values. The converted values of the vocalizations, together with the breed or species identifications, were used to train the ANNs following a ten-fold cross validation technique. Tests show that the respective ANNs can correctly identify 71.43\% of the birds, 94.44\% of the dogs, and 90.91\% of the frogs. This result show that bioacoustics and ANN can be used to automatically determine animal breeds and species, which together could be a promising automated tool for animal identification, biodiversity determination, animal conservation, and other animal welfare efforts.

cs.SD↗

arXiv2015

A Hybrid Graph-drawing Algorithm for Large, Naturally-clustered, Disconnected Graphs

In this paper, we present a hybrid graph-drawing algorithm (GDA) for layouting large, naturally-clustered, disconnected graphs. We called it a hybrid algorithm because it is an implementation of a series of already known graph-drawing and graph-theoretic procedures. We remedy in this hybrid the problematic nature of the current force-based GDA which has the inability to scale to large, naturally-clustered, and disconnected graphs. These kinds of graph usually model the complex inter-relationships among entities in social, biological, natural, and artificial networks. Obviously, the hybrid runs longer than the current GDAs. By using two extreme cases of graphs as inputs, we present in this paper the derivation of the time complexity of the hybrid which we found to be $O(|\V|^3)$.

cs.GR↗

arXiv2015

Ang Social Network sa Facebook ng mga Taga-Batangas at ng mga Taga-Laguna: Isang Paghahambing

Online social networking (OSN) has become of great influence to Filipinos, where Facebook, Twitter, LinkedIn, Google+, and Instagram are among the popular ones. Their popularity, coupled with their intuitive and interactive use, allow one's personal information such as gender, age, address, relationship status, and list of friends to become publicly available. The accessibility of information from these sites allow, with the aid of computers, for the study of a wide population's characteristics even in a provincial scale. Aside from being neighbouring locales, the respective residents of Laguna and Batangas both derive their livelihoods from two lakes, Laguna de Bay and Taal Lake. Both residents experience similar problems, such as that, among many others, of fish kill. The goal of this research is to find out similarities in their respective online populations, particularly that of Facebook's. With the use of computational dynamic social network analysis (CDSNA), we found out that the two communities are similar, among others, as follows: o Both populations are dominated by single young female o Homophily was observed when choosing a friend in terms of age (i.e., friendships were created more often between people whose ages do not differ by at most five years); and o Heterophily was observed when choosing friends in terms of gender (i.e., more friendships were created between a male and a female than between both people of the same gender). This paper also presents the differences in the structure of the two social networks, such as degrees of separation and preferential attachment.

cs.SI↗

arXiv2015

Neural Network Classifiers for Natural Food Products

Two cheap, off-the-shelf machine vision systems (MVS), each using an artificial neural network (ANN) as classifier, were developed, improved and evaluated to automate the classification of tomato ripeness and acceptability of eggs, respectively. Six thousand color images of human-graded tomatoes and 750 images of human-graded eggs were used to train, test, and validate several multi-layered ANNs. The ANNs output the corresponding grade of the produce by accepting as inputs the spectral patterns of the background-less image. In both MVS, the ANN with the highest validation rate was automatically chosen by a heuristic and its performance compared to that of the human graders'. Using the validation set, the MVS correctly graded 97.00\% and 86.00\% of the tomato and egg data, respectively. The human grader's, however, were measured to perform at a daily average of 92.65\% and 72.67\% for tomato and egg grading, respectively. This results show that an ANN-based MVS is a potential alternative to manual grading.

cs.CV↗

arXiv2015

On Web-grid Implementation Using Single System Image

With the latest innovations and trend towards personalizing users' web browsing experience, the web has been increasingly dominated by dynamic contents. However, delivering dynamic content remains a challenge due to the many dependencies involved in compiling the content, specifically personalized ones. This paper presents the use of Single System Image (SSI) clustering systems for a cheap, off-the-shelf, local lightweight distributed web-grid composed of desktop PCs. The three clustering systems considered in the study are Kerrighed, OpenSSI and openMosix. Through an online simulation technique, the performance savings achieved by the clustering systems were measured. Results showed that Kerrighed has the least number of missed requests while the response time is comparable with the rest.

cs.DC↗