scholarly journals LIMOFilling: Local Information Guide Hole-Filling and Sharp Feature Recovery for Manifold Meshes

2022 ◽  
Vol 14 (2) ◽  
pp. 289
Author(s):  
Guohua Gou ◽  
Haigang Sui ◽  
Dajun Li ◽  
Zhe Peng ◽  
Bingxuan Guo ◽  
...  

Manifold mesh, a triangular network for representing 3D objects, is widely used to reconstruct accurate 3D models of objects structure. The complexity of these objects and self-occlusion, however, can cause cameras to miss some areas, creating holes in the model. The existing hole-filling methods do not have the ability to detect holes at the model boundaries, leaving overlaps between the newly generated triangles, and also lack the ability to recover missing sharp features in the hole-region. To solve these problems, LIMOFilling, a new method for filling holes in 3D manifold meshes was proposed, and recovering the sharp features. The proposed method, detects the boundary holes robustly by constructing local overlap judgments, and provides the possibility for sharp features recovery using local structure information, as well as reduces the cost of maintaining manifold meshes thus enhancing their utility. The novel method against the existing methods have been tested on different types of holes in four scenes. Experimental results demonstrate the visual effect of the proposed method and the quality of the generated meshes, relative to the existing methods. The proposed hole-detection algorithm found almost all of the holes in different scenes and qualitatively, the subsequent repairs are difficult to see with the naked eye.

2016 ◽  
Vol 18 (1) ◽  
Author(s):  
Roelof Baard ◽  
George Nel

Background: Although research shows that almost all listed companies have corporate websites with dedicated investor relations (IR) sections that enable companies to ‘push’ information to investors, it was argued that such an asymmetrical approach to communication is insufficient for companies wishing to exercise good IR. The purpose of this study was to test the effectiveness of the Internet to act as a mechanism to achieve more interactive communication between companies and investors.Objectives: The objectives of the study were to measure the responsiveness, timeliness and relevance of companies’ responses to e-mail requests, and to test for the determinants (size, market-to-book ratio, profitability, leverage and liquidity) thereof.Method: The mystery investor approach and a content analysis were used to study the e-mail handling performance of companies. The associations between company-specific characteristics were statistically tested.Results: It was found that the e-mail handling performance of companies in this study was poor compared with previous studies. Significant relationships between company size and responsiveness and relevance, and between market-to-book ratio and relevance were reported, as well as between the contact method used to request information and relevance and the use of social media and timeliness.Conclusion: Specific areas where companies could improve their investor communications were identified. The need for further research was discussed to explain some of the relationships found, as well as those not found, in contrast to what was expected. Future research is warranted to examine the relationship between the e-mail handling performance of companies and information asymmetry and the cost of equity of companies.


2021 ◽  
Vol 13 (11) ◽  
pp. 6075
Author(s):  
Ola Lindroos ◽  
Malin Söderlind ◽  
Joel Jensen ◽  
Joakim Hjältén

Translocation of dead wood is a novel method for ecological compensation and restoration that could, potentially, provide a new important tool for biodiversity conservation. With this method, substrates that normally have long delivery times are instantly created in a compensation area, and ideally many of the associated dead wood dwelling organisms are translocated together with the substrates. However, to a large extent, there is a lack of knowledge about the cost efficiency of different methods of ecological compensation. Therefore, the costs for different parts of a translocation process and its dependency on some influencing factors were studied. The observed cost was 465 SEK per translocated log for the actual compensation measure, with an additional 349 SEK/log for work to enable evaluation of the translocation’s ecological results. Based on time studies, models were developed to predict required work time and costs for different transportation distances and load sizes. Those models indicated that short extraction and insertion distances for logs should be prioritized over road transportation distances to minimize costs. They also highlighted a trade-off between costs and time until a given ecological value is reached in the compensation area. The methodology used can contribute to more cost-efficient operations and, by doing so, increase the use of ecological compensation and the benefits from a given input.


2021 ◽  
pp. 34-37
Author(s):  
В.К. Сердеров ◽  
Д.В. Сердерова

Большое значение в увеличении продуктивности картофеля имеет внедрение в производство перспективных высокоурожайных сортов и гибридов, приспособленных к местным природно-климатическим условиям возделывания, от чего зависят эффективность отрасли и себестоимость продукции. Цель работы – изучить влияние климатических условий на продуктивность и качественные показатели сортов и гибридов картофеля, а также использование ими благоприятных почвенно-климатических условий высокогорья Республики Дагестан, для размножения и внедрения в производство новых перспективных, высокоурожайных, приспособленных к условиям среды выращивания сортов картофеля с комплексом хозяйственно-ценных признаков. Объектом изучения послужили сорта картофеля раннего, среднераннего и среднего сроков созревания российской, белорусской и иностранной селекции. Полевые опыты закладывали в 2014–2017 годах на высоте 2000–2200 м, на землях горного опорного пункта «Курахский» Курахского района и на равнинной провинции (Прикаспийской низменности) на территории дачного массива «Наука» Махачкалинского района Республики Дагестан. Схема посадки – 70×30 см, повторность – четырехкратная. Технология выращивания картофеля – гребневая. При проведении полевых опытов использовали общепринятые методики. Практически все сорта картофеля, выращенные на равнинной провинции, сформировали высокий урожай в первый год и при дальнейшем размножении в результате развития вирусных болезней резко снизили свои продуктивные качества. Наиболее высокая урожайность в среднем за три года отмечена у сортов Жуковский ранний (20,8 т/га), Импала (20,5 т/га), Невский (17,8 т/га), Предгорный (16,9 т/га) и Удача (16,3 т/га). В свою очередь, горная провинция Дагестана характеризовалась благоприятными почвенно-климатическими условиями для возделывания как продовольственного картофеля, так и для организации первичного семеноводства на безвирусной основе и размножения перспективных сортов этой культуры. В среднем за годы исследований в горной провинции по урожайности выделились сорта Сильвана (37,4 т/га), Удача (37,6 т/га), Рокко (33,3 т/га), Импала (31,7 т/га), Жуковский ранний (29,0 т/га), Предгорный (27,7 т/га) и Примобелла (27,7 т/га), а также гибриды № 12.40/17 (43,1 т/га) и № 13.61/61 (38,8 т/га). The introduction of promising high-yielding varieties and hybrids adapted to the local natural and climatic conditions of cultivation is of great importance in increasing the productivity of potatoes, which determines the efficiency of the industry and the cost of production. The aim of the work is to study the influence of climatic conditions on the productivity and quality indicators of potato varieties and hybrids, as well as their use of favorable soil and climatic conditions in the highlands of the Republic of Dagestan, for breeding and introducing into production new promising, high-yielding, adapted to the growing environment of potato varieties with a complex of economically valuable characteristics. The object of the study was potato varieties of early, mid-early and medium maturation periods of Russian, Belarusian and foreign selection. Field experiments were conducted in 2014–2017 at an altitude of 2000–2200 m, on the lands of the mountain stronghold Kurakhsky of the Kukhar district and on the plain province (the Caspian lowland) on the territory of the suburban area Nauka of the Makhachkala district of the Republic of Dagestan. The landing scheme is 70×30 cm, the repeatability is four times. The technology of growing potatoes is combed. When conducting field experiments, generally accepted methods were used. Almost all potato varieties grown in the lowland province formed a high yield in the first year and, with further propagation, as a result of the development of viral diseases, sharply reduced their productive qualities. The highest yield on average for three years was observed in the varieties Zhukovskiy ranniy (20.8 t/ha), Impala (20.5 t/ha), Nevsky (17.8 t/ha), Predgornyy (16.9 t/ha) and Udacha (16.3 t/ha). In turn, the mountain province of Dagestan was characterized by favorable soil and climatic conditions for the cultivation of both food potatoes, and for the organization of primary seed production on a virus-free basis and the reproduction of promising varieties of this crop. On average, over the years of research in the mountain province, the varieties Silvana (37.4 t/ha), Udacha (37.6 t/ha), Rocco (33.3 t/ha), Impala (31.7 t/ha), Zhukovskiy ranniy (29.0 t/ha), Predgornyy (27.7 t/ha) and Primobella (27.7 t/ha), as well as hybrids No.12.40/17 (43.1 t/ha) and No.13.61/61 (38.8 t/ha) were distinguished by yield.


2021 ◽  
pp. 1-62
Author(s):  
Rozenn Gazan ◽  
Florent Vieux ◽  
Ségolène Mora ◽  
Sabrina Havard ◽  
Carine Dubuisson

Abstract Objective: To describe existing online 24-hour dietary recall (24hDR) tools in terms of functionalities and ability to tackle challenges encountered during national dietary surveys, such as maximizing response rates and collecting high-quality data from a representative sample of the population, while minimizing the cost and response burden. Design: A search (from 2000 to 2019) was conducted in peer-reviewed and grey literature. For each tool, information on functionalities, validation and user usability studies, and potential adaptability for integration into a new context was collected. Setting: Not country-specific Participants: General population Results: Eighteen online 24hDR tools were identified. Most were developed in Europe, for children ≥10 years old and/or for adults. Eight followed the five multiple-pass steps, but used various methodologies and features. Almost all tools (except three) validated their nutrient intake estimates, but with high heterogeneity in methodologies. User usability was not always assessed, and rarely by applying real-time methods. For researchers, eight tools developed a web platform to manage the survey and five appeared to be easily adaptable to a new context. Conclusions: Among the eighteen online 24hDR tools identified, the best candidates to be used in national dietary surveys should be those that were validated for their intake estimates, had confirmed user and researcher usability, and seemed sufficiently flexible to be adapted to new contexts. Regardless of the tool, adaptation to another context will still require time and funding, and this is probably the most challenging step.


2018 ◽  
Vol 246 ◽  
pp. 03020
Author(s):  
Tan Wei ◽  
Xuan Liu ◽  
Chen Yi ◽  
Erfu Yang

With the development of industrial automation, location measurement of 3D objects is becoming more and more important, especially as it can provide necessary positional parameters for the manipulator to grasp the object accurately. In view of the disabled object which is in widespread use currently, its image is captured to obtain positional parameters and transmitted to manipulators in industry. The above process is delayed, affecting the work efficiency of the manipulator. A method for calculating the position information of target object in motion is proposed. This method uses monocular vision technology to track 3D moving objects,then uses contour sorting method to extract the minimum constrained contour rectangle, and combines the video alignment technology to realize the tracking. Thus, the measurement error is reduced. The experimental results and analysis show that the adopted measurement method is effective.


2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Huaping Guo ◽  
Xiaoyu Diao ◽  
Hongbing Liu

Rotation Forest is an ensemble learning approach achieving better performance comparing to Bagging and Boosting through building accurate and diverse classifiers using rotated feature space. However, like other conventional classifiers, Rotation Forest does not work well on the imbalanced data which are characterized as having much less examples of one class (minority class) than the other (majority class), and the cost of misclassifying minority class examples is often much more expensive than the contrary cases. This paper proposes a novel method called Embedding Undersampling Rotation Forest (EURF) to handle this problem (1) sampling subsets from the majority class and learning a projection matrix from each subset and (2) obtaining training sets by projecting re-undersampling subsets of the original data set to new spaces defined by the matrices and constructing an individual classifier from each training set. For the first method, undersampling is to force the rotation matrix to better capture the features of the minority class without harming the diversity between individual classifiers. With respect to the second method, the undersampling technique aims to improve the performance of individual classifiers on the minority class. The experimental results show that EURF achieves significantly better performance comparing to other state-of-the-art methods.


2019 ◽  
Vol 25 (3) ◽  
pp. 496-514 ◽  
Author(s):  
Nataraj Poomathi ◽  
Sunpreet Singh ◽  
Chander Prakash ◽  
Rajkumar V. Patil ◽  
P.T. Perumal ◽  
...  

Purpose Bioprinting is a promising technology, which has gained a recent attention, for application in all aspects of human life and has specific advantages in different areas of medicines, especially in ophthalmology. The three-dimensional (3D) printing tools have been widely used in different applications, from surgical planning procedures to 3D models for certain highly delicate organs (such as: eye and heart). The purpose of this paper is to review the dedicated research efforts that so far have been made to highlight applications of 3D printing in the field of ophthalmology. Design/methodology/approach In this paper, the state-of-the-art review has been summarized for bioprinters, biomaterials and methodologies adopted to cure eye diseases. This paper starts with fundamental discussions and gradually leads toward the summary and future trends by covering almost all the research insights. For better understanding of the readers, various tables and figures have also been incorporated. Findings The usages of bioprinted surgical models have shown to be helpful in shortening the time of operation and decreasing the risk of donor, and hence, it could boost certain surgical effects. This demonstrates the wide use of bioprinting to design more precise biological research models for research in broader range of applications such as in generating blood vessels and cardiac tissue. Although bioprinting has not created a significant impact in ophthalmology, in recent times, these technologies could be helpful in treating several ocular disorders in the near future. Originality/value This review work emphasizes the understanding of 3D printing technologies, in the light of which these can be applied in ophthalmology to achieve successful treatment of eye diseases.


2019 ◽  
Vol 147 (1-2) ◽  
pp. 10-16
Author(s):  
Marijana Arapovic-Savic ◽  
Mihajlo Savic ◽  
Mirjana Umicevic-Davidovic ◽  
Adriana Arbutina ◽  
Nenad Nedeljkovic ◽  
...  

Introduction/Objective. Rapid developments in information technologies lead to the wider use of digital representations of dental study models in orthodontics. Most popular way of digitizing the models is to use a 3D scanner and then perform measurements on 3D models, which requires additional and expensive hardware and software resources. In this paper we present an alternative approach based on the use of photogrammetry in the newly developed OrthoPhoto4D software that calculates and corrects perspective distortion errors. Methods. We measured individual tooth width for 24 teeth, 12 two-teeth segments as well as inter-molar and inter-canine distances on 50 models. Measurements are performed in OrthoPhoto4D software that uses four photographs of each model for measurements, uses QR codes for automation, calculates the camera position and corrects perspective distortion-caused errors in measurements. Obtained measurements are compared to ones obtained from models generated by structured light 3D scanner. Results. Statistical analysis strongly indicates that there is no significant difference between the two methods. The recorded differences also have no clinical impact as they have mean values of 0.2 mm for individual tooth widths, approximately 0.2 mm for two teeth segments, and under 0.3 mm for both intercanine and inter-molar distances. All recorded differences fall within the expected measurement error. Conclusion. We concluded that the described photogrammetry measurements performed in OrthoPhoto4D can be used in diagnosis and therapy planning.


2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Kurniawan Kurniawan ◽  
Dody Hapsoro

This study examines whether there are differences in the cost of the loan risk reserves and the loan risk reserves between audit results data and financial reporting. The research sample consisted of the audit results report on 50 BKM (Badan Keswadayaan Masyarakat) in Kabupaten Bantul Provinsi Daerah IstimewaYogyakarta whichhave been audited by Budiman, Wawan, Pamudji and Partners Public Accounting Firmin 2014. This study found that the cost of the loan risk allowances and loan risk allowances between audit result and reporting differed significantly. The study concluded that almost all of BKM not charge cost and reserve risk of the loan according collectibility list that is used as the source of the audit resultscalculation. Keywords: Cost of the loan risk reserves, loan risk reserves, audit results, reporting.


Author(s):  
J. Doblas ◽  
A. Carneiro ◽  
Y. Shimabukuro ◽  
S. Sant’Anna ◽  
L. Aragão ◽  
...  

Abstract. In this study we analyse the factors of variability of Sentinel-1 C-band radar backscattering over tropical rainforests, and propose a method to reduce the effects of this variability on deforestation detection algorithms. To do so, we developed a random forest regression model that relates Sentinel-1 gamma nought values with local climatological data and forest structure information. The model was trained using long time-series of 26 relevant variables, sampled over 6 undisturbed tropical forests areas. The resulting model explained 71.64% and 73.28% of the SAR signal variability for VV and VH polarizations, respectively. Once the best model for every polarization was selected, it was used to stabilize extracted pixel-level data of forested and non-deforested areas, which resulted on a 10 to 14% reduction of time-series variability, in terms of standard deviation. Then a statistically robust deforestation detection algorithm was applied to the stabilized time-series. The results show that the proposed method reduced the rate of false positives on both polarizations, especially on VV (from 21% to 2%, α=0.01). Meanwhile, the omission errors increased on both polarizations (from 27% to 37% in VV and from 27% to 33% on VV, α=0.01). The proposed method yielded slightly better results when compared with an alternative state-of-the-art approach (spatial normalization).


Sign in / Sign up

Export Citation Format

Share Document