Pub Date : 2020-11-16DOI: 10.1109/SCCC51225.2020.9281148
Oliver Sumari H. Felix, C. Juan
The Drone is an unmanned aerial vehicle widely used to take pictures and record videos at high altitude, recording information for applications such as video surveillance, to be able to detect cars and people in real time, the main problem is that both the drone as objects are move, this make difficult the track objects with traditional techniques. Faced this problem, the present research proposes the use of convolutional neural network with multidomain learning (MDNet) and camera movement models for the detection and monitoring of cars based on aerial videos. The propouse obtaining very good results in compare with traditional methods, obtaining a 90 % of success in object tracking, which is useful for practical applications.
{"title":"Multi-Domain Network Performance Analysis for Vehicle Tracking in Aerial Video","authors":"Oliver Sumari H. Felix, C. Juan","doi":"10.1109/SCCC51225.2020.9281148","DOIUrl":"https://doi.org/10.1109/SCCC51225.2020.9281148","url":null,"abstract":"The Drone is an unmanned aerial vehicle widely used to take pictures and record videos at high altitude, recording information for applications such as video surveillance, to be able to detect cars and people in real time, the main problem is that both the drone as objects are move, this make difficult the track objects with traditional techniques. Faced this problem, the present research proposes the use of convolutional neural network with multidomain learning (MDNet) and camera movement models for the detection and monitoring of cars based on aerial videos. The propouse obtaining very good results in compare with traditional methods, obtaining a 90 % of success in object tracking, which is useful for practical applications.","PeriodicalId":117157,"journal":{"name":"2020 39th International Conference of the Chilean Computer Science Society (SCCC)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121354922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-16DOI: 10.1109/SCCC51225.2020.9281256
Roberto I. González-Ibáñez, Jacqueline Köhler, Esteban Gaete-Flores, Fernanda Estay-Cabello, Angus Pollmann-Stocker, Jonathan Catalán-Álvarez
During the last decades, the way people interact with information has drastically changed as a result of the rapid proliferation of new technologies and the arrival of the World Wide Web. This technological evolution has propitiated a transition from physical information objects such as books to their digital and ethereal versions. As a result, an interaction gap between individuals and information objects has emerged. As new technologies appear, alternative possibilities to interact with information can be envisioned, however, little is known about the benefits and costs of such interaction forms (e. g. body-based, virtual and augmented reality, among others). Furthermore, the complexity and cost of conducting studies with technologies such as the above mentioned can be particularly high. To address these problems, we introduce MOTIONS (huMan-infOrmation inTeractION System), a system to conduct evaluations and experiments on human-information interactions with multiple types of interfaces. Additionally, we present a synthesis of case studies conducted using MOTIONS with the aim to compare different types of interactions with digital information objects. On the one hand, these studies demonstrate MOTIONS’ utility as a research tool. On the other hand, results suggest that state-of-the-art interaction technology, while appealing, may not be necessarily cost-effective in terms of performance and user experience. These results shed light not only about potential uses of MOTIONS, but also about design decisions when developing new interfaces to interact with information objects in the digital realm.
{"title":"MOTIONS: Exploring Human-Information Interactions Beyond Clicks","authors":"Roberto I. González-Ibáñez, Jacqueline Köhler, Esteban Gaete-Flores, Fernanda Estay-Cabello, Angus Pollmann-Stocker, Jonathan Catalán-Álvarez","doi":"10.1109/SCCC51225.2020.9281256","DOIUrl":"https://doi.org/10.1109/SCCC51225.2020.9281256","url":null,"abstract":"During the last decades, the way people interact with information has drastically changed as a result of the rapid proliferation of new technologies and the arrival of the World Wide Web. This technological evolution has propitiated a transition from physical information objects such as books to their digital and ethereal versions. As a result, an interaction gap between individuals and information objects has emerged. As new technologies appear, alternative possibilities to interact with information can be envisioned, however, little is known about the benefits and costs of such interaction forms (e. g. body-based, virtual and augmented reality, among others). Furthermore, the complexity and cost of conducting studies with technologies such as the above mentioned can be particularly high. To address these problems, we introduce MOTIONS (huMan-infOrmation inTeractION System), a system to conduct evaluations and experiments on human-information interactions with multiple types of interfaces. Additionally, we present a synthesis of case studies conducted using MOTIONS with the aim to compare different types of interactions with digital information objects. On the one hand, these studies demonstrate MOTIONS’ utility as a research tool. On the other hand, results suggest that state-of-the-art interaction technology, while appealing, may not be necessarily cost-effective in terms of performance and user experience. These results shed light not only about potential uses of MOTIONS, but also about design decisions when developing new interfaces to interact with information objects in the digital realm.","PeriodicalId":117157,"journal":{"name":"2020 39th International Conference of the Chilean Computer Science Society (SCCC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129343869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-16DOI: 10.1109/SCCC51225.2020.9281279
Rafael Saltos-Rivas, Pavel Novoa-Hernández, Rocío Serrano Rodríguez
This paper aims to provide an overview of the reliability and validity of the instruments used to measure digital competence in higher education. Three research questions were addressed about: 1) the demographic and methodological characteristics of the literature, 2) typical assessments and reporting practices, and 3) the association between studies’ characteristics and their reporting practices. Through a systematic mapping study, 60 primary studies published in the period 2018-2020 were analyzed and classified. The results indicated that most of the studies originated in Europe and Asia; they focused on university students from Social Sciences; they administered instruments composed of cognitive items for diagnosing digital competence; they were published in journals not indexed by the Journal Citation Report; and about 50% did not report on the reliability and validity of the instrument used. Studies published in low-quality journals or focused on administration only are more susceptible to not reporting these psychometric assessments.
{"title":"On the Reliability and Validity of Digital Competence Evaluation in Higher Education","authors":"Rafael Saltos-Rivas, Pavel Novoa-Hernández, Rocío Serrano Rodríguez","doi":"10.1109/SCCC51225.2020.9281279","DOIUrl":"https://doi.org/10.1109/SCCC51225.2020.9281279","url":null,"abstract":"This paper aims to provide an overview of the reliability and validity of the instruments used to measure digital competence in higher education. Three research questions were addressed about: 1) the demographic and methodological characteristics of the literature, 2) typical assessments and reporting practices, and 3) the association between studies’ characteristics and their reporting practices. Through a systematic mapping study, 60 primary studies published in the period 2018-2020 were analyzed and classified. The results indicated that most of the studies originated in Europe and Asia; they focused on university students from Social Sciences; they administered instruments composed of cognitive items for diagnosing digital competence; they were published in journals not indexed by the Journal Citation Report; and about 50% did not report on the reliability and validity of the instrument used. Studies published in low-quality journals or focused on administration only are more susceptible to not reporting these psychometric assessments.","PeriodicalId":117157,"journal":{"name":"2020 39th International Conference of the Chilean Computer Science Society (SCCC)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130234198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-16DOI: 10.1109/SCCC51225.2020.9281219
Alan Silva, Romina Torres, Sven von Brand
"Gamification" is a contemporary pedagogic strategy that has been incorporated into the field of pedagogy. Gamification takes game’s elements and characteristics, to be used in non-recreational activities such as pedagogy with the aim of enhancing motivation and improving learning. Due to the rapid advance of technology, Gamification is no longer limited to be used only with traditional games but also has begun to be used with video games. This article aims to raise the idea of using gamification in conjunction with current technologies to create a product capable of teaching children to take care of themselves in order to prevent the contagion and spread of COVID-19 in case childrens had to return to school.
{"title":"Brigada Covid: health education game for preschoolers","authors":"Alan Silva, Romina Torres, Sven von Brand","doi":"10.1109/SCCC51225.2020.9281219","DOIUrl":"https://doi.org/10.1109/SCCC51225.2020.9281219","url":null,"abstract":"\"Gamification\" is a contemporary pedagogic strategy that has been incorporated into the field of pedagogy. Gamification takes game’s elements and characteristics, to be used in non-recreational activities such as pedagogy with the aim of enhancing motivation and improving learning. Due to the rapid advance of technology, Gamification is no longer limited to be used only with traditional games but also has begun to be used with video games. This article aims to raise the idea of using gamification in conjunction with current technologies to create a product capable of teaching children to take care of themselves in order to prevent the contagion and spread of COVID-19 in case childrens had to return to school.","PeriodicalId":117157,"journal":{"name":"2020 39th International Conference of the Chilean Computer Science Society (SCCC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124110140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-16DOI: 10.1109/SCCC51225.2020.9281261
J. Salas-Morales, J. Munoz-Gama
Nowadays, programming courses are based on the Learning by Doing, where students interactively code, and programming judges automatically assess their codes against testcases. Although the use of students computers is common for both formative and long summative assessments, many short summative assessments (e.g., exams) still rely on institution computers to avoid plagiarism. The number of computers and access to internet necessary for massive courses makes this an inapplicable option for lots of institutions. This works presents OSTIA (Offline System for Testcase Interactive Assessments), a low cost alternative based on the students computers, without requiring internet, but guaranteeing that the assessment is done individually. The system involves a pendrive-based operating system, containing an offline programming judge and testcases. It allows the student to program interactively and assess their codes locally, restricting the access to other resources. The grades are collected using QR codes and an offline mobile app.
{"title":"OSTIA: A Low Cost Alternative for Short Summative Assessments in Massive Programming Courses","authors":"J. Salas-Morales, J. Munoz-Gama","doi":"10.1109/SCCC51225.2020.9281261","DOIUrl":"https://doi.org/10.1109/SCCC51225.2020.9281261","url":null,"abstract":"Nowadays, programming courses are based on the Learning by Doing, where students interactively code, and programming judges automatically assess their codes against testcases. Although the use of students computers is common for both formative and long summative assessments, many short summative assessments (e.g., exams) still rely on institution computers to avoid plagiarism. The number of computers and access to internet necessary for massive courses makes this an inapplicable option for lots of institutions. This works presents OSTIA (Offline System for Testcase Interactive Assessments), a low cost alternative based on the students computers, without requiring internet, but guaranteeing that the assessment is done individually. The system involves a pendrive-based operating system, containing an offline programming judge and testcases. It allows the student to program interactively and assess their codes locally, restricting the access to other resources. The grades are collected using QR codes and an offline mobile app.","PeriodicalId":117157,"journal":{"name":"2020 39th International Conference of the Chilean Computer Science Society (SCCC)","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128319505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-16DOI: 10.1109/SCCC51225.2020.9281266
Marco A. Palomino, Aditya Padmanabhan Varma
Anecdotal evidence suggests that Twitter trends are characterised by highly polarised tweets. However, specific experiments intended to measure the correlation between the emergence of a trend and the overall sentiment expressed on it have been few and limited. Thus, we have launched an investigation to ascertain the nature of the relationship between trends and strength of sentiment. As a testbed for our experimentation, we have retrieved a large collection of tweets related to the COVID19 pandemic, in the particular context of the UK Government briefings broadcasted in the media. Our results highlight the presence of a significant percentage of trends with a nearly neutral sentiment. Indeed, there does not seem to be an apparent correlation between trends and polarity.
{"title":"Any Publicity is Good Publicity: Positive, Negative and Neutral Tweets Can All Become Trends","authors":"Marco A. Palomino, Aditya Padmanabhan Varma","doi":"10.1109/SCCC51225.2020.9281266","DOIUrl":"https://doi.org/10.1109/SCCC51225.2020.9281266","url":null,"abstract":"Anecdotal evidence suggests that Twitter trends are characterised by highly polarised tweets. However, specific experiments intended to measure the correlation between the emergence of a trend and the overall sentiment expressed on it have been few and limited. Thus, we have launched an investigation to ascertain the nature of the relationship between trends and strength of sentiment. As a testbed for our experimentation, we have retrieved a large collection of tweets related to the COVID19 pandemic, in the particular context of the UK Government briefings broadcasted in the media. Our results highlight the presence of a significant percentage of trends with a nearly neutral sentiment. Indeed, there does not seem to be an apparent correlation between trends and polarity.","PeriodicalId":117157,"journal":{"name":"2020 39th International Conference of the Chilean Computer Science Society (SCCC)","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130243616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-16DOI: 10.1109/SCCC51225.2020.9281223
J. Cedeño, A. Lozada, R. Olivares, N. Jara
One of the main problems in the design of elastic optical networks is the Routing, Modulation-Level, and Spectrum Assignment problem (RMLSA). In this work, we propose new strategies to solve the spectrum assignment (SA) sub-problem for EONs architectures with static network operation. To this end, we developed two new approaches called Sliding-Fit (SF) and Parcel-Fit (PF), focused on minimizing the spectrum fragmentation obtained when attending network demands. These strategies change to standard paradigm use to search an amount of consecutive FSUs for a given user by choosing a subset of FSUs in the frequency spectrum and later finding users for the selected FSUs. Additionally, the method relies on a physical-later impairment (PLI) model to compute the maximum optical reach and bandwidth demands based on the modulation level - bitrate pair.Experimental results showed that the proposed algorithms obtain less spectrum fragmentation than the best found in the literature, allowing to assign a higher number of users, decreasing the network capacity or increasing the efficiency in the use of resources.
{"title":"Fragmentation-aware spectrum assignment strategies for elastic optical networks with static operation","authors":"J. Cedeño, A. Lozada, R. Olivares, N. Jara","doi":"10.1109/SCCC51225.2020.9281223","DOIUrl":"https://doi.org/10.1109/SCCC51225.2020.9281223","url":null,"abstract":"One of the main problems in the design of elastic optical networks is the Routing, Modulation-Level, and Spectrum Assignment problem (RMLSA). In this work, we propose new strategies to solve the spectrum assignment (SA) sub-problem for EONs architectures with static network operation. To this end, we developed two new approaches called Sliding-Fit (SF) and Parcel-Fit (PF), focused on minimizing the spectrum fragmentation obtained when attending network demands. These strategies change to standard paradigm use to search an amount of consecutive FSUs for a given user by choosing a subset of FSUs in the frequency spectrum and later finding users for the selected FSUs. Additionally, the method relies on a physical-later impairment (PLI) model to compute the maximum optical reach and bandwidth demands based on the modulation level - bitrate pair.Experimental results showed that the proposed algorithms obtain less spectrum fragmentation than the best found in the literature, allowing to assign a higher number of users, decreasing the network capacity or increasing the efficiency in the use of resources.","PeriodicalId":117157,"journal":{"name":"2020 39th International Conference of the Chilean Computer Science Society (SCCC)","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123130199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-16DOI: 10.1109/SCCC51225.2020.9281214
Julio Rojas-Mora, O. Herrera, P. Mirabal, M. Lévano
The pandemic context forced most of the Higher Education Institutions, and therefore their faculties, to face a semester of teaching in an online mode. The universities defined general guidelines and strategies to try to guarantee a minimum quality of the process. However, the literature reports that, depending on its particularities, preparing a semester-long online course requires a design of several months. Therefore, each lecturer worked according to her experience, guidelines, and support she received: "What could be done, was done." This article reports the teaching experience of the 1st semester 2020 of the Computer Science undergraduate program at the Universidad Católica de Temuco. Some lecturers of this undergraduate program had previous experience in online training; hence they designed strategies that differed in teaching, evaluation, and interaction methodologies while using several technologies available to them. A sample of 115 of our students answered a questionnaire to assess the preferences and problems during this semester. The results show a heterogeneous set of clusters. However, they point to a constructivist asynchronous vision in a group of our students that prefer short videos uploaded by their professors, and the resources that, by their means, they find on the Internet, point towards a constructivist asynchronous vision in a group of our students. The results also allowed us to rescue good practices that help in proposing an emergency online teaching model that will guide the design of the second-semester courses.
大流行的背景迫使大多数高等教育机构，因此他们的教师，面临一个学期的在线教学模式。大学定义了一般的指导方针和策略，试图保证最低质量的过程。然而，文献报道，根据其特殊性，准备一个学期的在线课程需要几个月的设计。因此，每位讲师都根据自己的经验、指导方针和得到的支持来工作:“能做的，都做了。”本文报告了Católica de Temuco大学2020年第一学期计算机科学本科课程的教学经验。本专业部分讲师有网络培训经验;因此，他们设计了不同于教学、评估和互动方法的策略，同时使用了几种可用的技术。我们的115名学生回答了一份调查问卷，以评估本学期的偏好和问题。结果显示了一个异构的簇集。然而，他们指出，在我们的一群学生中，有一种建构主义的异步观点，他们更喜欢教授上传的短视频，而他们在互联网上找到的资源，也表明，在我们的一群学生中，有一种建构主义的异步观点。研究结果还使我们能够挽救一些好的做法，这些做法有助于提出一种紧急在线教学模式，该模式将指导第二学期课程的设计。
{"title":"Methodological recommendations to face an online semester in a catastrophic situation: the case of a computer science program during the COVID-19 lockdown","authors":"Julio Rojas-Mora, O. Herrera, P. Mirabal, M. Lévano","doi":"10.1109/SCCC51225.2020.9281214","DOIUrl":"https://doi.org/10.1109/SCCC51225.2020.9281214","url":null,"abstract":"The pandemic context forced most of the Higher Education Institutions, and therefore their faculties, to face a semester of teaching in an online mode. The universities defined general guidelines and strategies to try to guarantee a minimum quality of the process. However, the literature reports that, depending on its particularities, preparing a semester-long online course requires a design of several months. Therefore, each lecturer worked according to her experience, guidelines, and support she received: \"What could be done, was done.\" This article reports the teaching experience of the 1st semester 2020 of the Computer Science undergraduate program at the Universidad Católica de Temuco. Some lecturers of this undergraduate program had previous experience in online training; hence they designed strategies that differed in teaching, evaluation, and interaction methodologies while using several technologies available to them. A sample of 115 of our students answered a questionnaire to assess the preferences and problems during this semester. The results show a heterogeneous set of clusters. However, they point to a constructivist asynchronous vision in a group of our students that prefer short videos uploaded by their professors, and the resources that, by their means, they find on the Internet, point towards a constructivist asynchronous vision in a group of our students. The results also allowed us to rescue good practices that help in proposing an emergency online teaching model that will guide the design of the second-semester courses.","PeriodicalId":117157,"journal":{"name":"2020 39th International Conference of the Chilean Computer Science Society (SCCC)","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131124128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-16DOI: 10.1109/SCCC51225.2020.9281199
Mauricio Moyano, Guillermo Cabrera-Guerrero
Radiotherapy (also called Radiation therapy) is a cancer treatment that uses high doses of radiation to destroy cancer cells and shrink tumors. Into external radiotherapy, there is the Intensity Modulated Radiation Therapy (known as IMRT), where it is taken a specific part of the body through the deliver the dose from different angles to damage the tumor, avoiding surrounding organs.When IMRT is approached as a sequential problem, we first need to establish a set of beam angles from which radiation will be released. Then, the radiation intensities for each selected beam angles are computed. Finally, the sequence of apertures we need to deliver the computed treatment plan is generated. Unlike this sequential approach, in the Direct Aperture Optimization (DAO) problems, constraints associated with the number of deliverable aperture shapes, just as some physical constraints, are taken into consideration while the intensities optimisation process is taking place. According to some authors, DAO generates better treatments with fewer apertures for IMRT.In this work, we propose a heuristic algorithm, mixing a local search algorithm and mathematical programming to solve the DAO problem. We apply our algorithm on a prostate cancer case and compare ours results with those obtained in the sequential approach. Results show that our algorithms can find treatment plans in competitive time when considering the number of deliverable aperture shapes.
{"title":"Local Search for the Direct Aperture Optimisation in IMRT","authors":"Mauricio Moyano, Guillermo Cabrera-Guerrero","doi":"10.1109/SCCC51225.2020.9281199","DOIUrl":"https://doi.org/10.1109/SCCC51225.2020.9281199","url":null,"abstract":"Radiotherapy (also called Radiation therapy) is a cancer treatment that uses high doses of radiation to destroy cancer cells and shrink tumors. Into external radiotherapy, there is the Intensity Modulated Radiation Therapy (known as IMRT), where it is taken a specific part of the body through the deliver the dose from different angles to damage the tumor, avoiding surrounding organs.When IMRT is approached as a sequential problem, we first need to establish a set of beam angles from which radiation will be released. Then, the radiation intensities for each selected beam angles are computed. Finally, the sequence of apertures we need to deliver the computed treatment plan is generated. Unlike this sequential approach, in the Direct Aperture Optimization (DAO) problems, constraints associated with the number of deliverable aperture shapes, just as some physical constraints, are taken into consideration while the intensities optimisation process is taking place. According to some authors, DAO generates better treatments with fewer apertures for IMRT.In this work, we propose a heuristic algorithm, mixing a local search algorithm and mathematical programming to solve the DAO problem. We apply our algorithm on a prostate cancer case and compare ours results with those obtained in the sequential approach. Results show that our algorithms can find treatment plans in competitive time when considering the number of deliverable aperture shapes.","PeriodicalId":117157,"journal":{"name":"2020 39th International Conference of the Chilean Computer Science Society (SCCC)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132680136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-16DOI: 10.1109/SCCC51225.2020.9281215
P. Mirabal, José Ignacio Abreu Salas, Diego Seco, Oscar Pedreira, Edgar Chávez
The median string problem is NP-hard under several formulations, being the most competitive heuristics those using perturbation-based iterative algorithms. The initial string and the policy to order possible edit operations are key to the efficiency of such approaches. In this work, we tackle both sub-problems. We hypothesized that a better starting point for the algorithm can reduce the number of edit distances computed to obtain the median string, improving time performance without degrading the quality of the solution. Regarding the starting point, we use the median of a few strings of the input, that is selected as the Half Space Proximal (HSP) neighbors of the median of the set. The HSP neighbors are simultaneously close to the center but also diverse among them. To validate these results, we present comparative experiments, attending mainly to the quality of the median obtained, the time to compute such median, and the number of edit distances computed.
{"title":"New initialization for algorithms to solve Median String Problem","authors":"P. Mirabal, José Ignacio Abreu Salas, Diego Seco, Oscar Pedreira, Edgar Chávez","doi":"10.1109/SCCC51225.2020.9281215","DOIUrl":"https://doi.org/10.1109/SCCC51225.2020.9281215","url":null,"abstract":"The median string problem is NP-hard under several formulations, being the most competitive heuristics those using perturbation-based iterative algorithms. The initial string and the policy to order possible edit operations are key to the efficiency of such approaches. In this work, we tackle both sub-problems. We hypothesized that a better starting point for the algorithm can reduce the number of edit distances computed to obtain the median string, improving time performance without degrading the quality of the solution. Regarding the starting point, we use the median of a few strings of the input, that is selected as the Half Space Proximal (HSP) neighbors of the median of the set. The HSP neighbors are simultaneously close to the center but also diverse among them. To validate these results, we present comparative experiments, attending mainly to the quality of the median obtained, the time to compute such median, and the number of edit distances computed.","PeriodicalId":117157,"journal":{"name":"2020 39th International Conference of the Chilean Computer Science Society (SCCC)","volume":"124 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114746516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：