Virtual Table Research Articles

IVT: an efficient method for sharing subtype polymorphic objects

Shared memory provides the fastest form of inter-process communication. Sharing polymorphic objects between different address spaces requires solving the issue of sharing pointers. In this paper, we propose a method, named Indexed Virtual Tables (IVT for short), to share polymorphic objects efficiently. On object construction, the virtual table pointers are replaced with indexes, which are used to find the actual virtual table pointers on dynamic dispatch. Only a few addition and load instructions are needed for both operations. Experimental results show that the IVT can outperform prior techniques on both object construction time and dynamic dispatch time. We also apply the proposed IVT technique to several practical scenarios, resulting the improvement of overall performance.

ВІРТУАЛЬНИЙ ІНСТРУМЕНТАРІЙ ДЛЯ ДОСЛІДЖЕННЯ ХВИЛЕВОДУ ПРЯМОКУТНОГО ПЕРЕТИНУ

The rectangular waveguide is the most common type of transmission line in millimeter, centimeter, and short-wave part of decimeter range. It allows to transmit quite significant levels of power with a small attenuation, is broadband and mechanically strong. The mode of operation of the transmission line is characterized by a number of parameters, which during its operation are subject to control and are maintained within certain limits by the prescribed adjustments. In order to study waves in a rectangular waveguide for educational purposes, it is often enough to simulate a computer model that can replace a complex of valuable equipment. In this work, a virtual table in a LabView environment, which allows to carry out simulation in order to determine electromagnetic wave parameters in a rectangular waveguide, is synthesized. For a wave of a given type with arbitrary coupling of m and n indices propagating over a waveguide with given geometric dimensions of the cross section, it is possible to determine critical wavelength or critical frequency. Also, the developed virtual toolkit allows to investigate the dispersion in the waveguide, to estimate the value of losses in the waveguide and the efficiency, to determine, separately for the waves of E and H types, characteristic resistance of the waveguide and reflection coefficient. Analytical expressions are obtained to calculate the breakdown power of a waveguide in the propagation of waves of E and H types, which are also implemented as appropriate virtual instruments. The developed virtual toolkit allows to organize distance learning. The synthesized virtual table is a convenient tool for studying the parameters and characteristics of a rectangular waveguide, and when used in the learning process, it will contribute to improving the understanding of the physical processes occurring in the propagation of wavelengths of E and H types in the waveguide.

Combining Deep Learning and Qualitative Spatial Reasoning to Learn Complex Structures from Sparse Examples with Noise

Many modern machine learning approaches require vast amounts of training data to learn new concepts; conversely, human learning often requires few examples—sometimes only one—from which the learner can abstract structural concepts. We present a novel approach to introducing new spatial structures to an AI agent, combining deep learning over qualitative spatial relations with various heuristic search algorithms. The agent extracts spatial relations from a sparse set of noisy examples of block-based structures, and trains convolutional and sequential models of those relation sets. To create novel examples of similar structures, the agent begins placing blocks on a virtual table, uses a CNN to predict the most similar complete example structure after each placement, an LSTM to predict the most likely set of remaining moves needed to complete it, and recommends one using heuristic search. We verify that the agent learned the concept by observing its virtual block-building activities, wherein it ranks each potential subsequent action toward building its learned concept. We empirically assess this approach with human participants’ ratings of the block structures. Initial results and qualitative evaluations of structures generated by the trained agent show where it has generalized concepts from the training data, which heuristics perform best within the search space, and how we might improve learning and execution.

A survey on wireless sensor network databases

In recent years, the use of wireless sensors has increased drastically in most fields. Wireless Sensor Networks (WSNs) have attracted the interest of industries and they have been used in several application areas (military, health, transportation, agriculture). WSNs are ad-hoc networks, composed of sensor nodes, which are deployed in an area of interest, in order to monitor and to return information requested by users. Sensor data is transmitted to users over a central station, named base station. Data collection becomes more difficult when the number of sensors increases. Since about a decade, intensive research has started in order to deal with these problems. Many researchers suggested to structure the sensor data in the form of a database and reduce the number of communications and energy consumption in the network. They have often considered the network as a large database and the sensor node as a virtual table. In this article, the existing sensor database approaches in WSNs are studied. Firstly, we will provide the definition of sensor databases, then we will present their architecture and their characteristics. Thereafter, we will present and compare existing sensor database systems. Finally, we will conclude this paper with a discussion of some research issues in the field of sensor databases.

Anatomage Virtual Dissection Table: a Supplemental Learning Aid for Human Anatomy Education During an Undergraduate Outreach Activity

Learning anatomy from books has its limitations. Cadaver dissection and prosection had proven to be the ideal method of learning anatomy, though they also have restrictions. Commercially, there are several tools for the enhancement of learning and teaching anatomy, such as 3D virtual anatomy apps and anatomical models. The Anatomage, a virtual anatomy dissection table, is a powerful virtual table with capabilities of dissection and prosection of the complete human body or segments.PurposeEnhance anatomical learning through the use of prosections of human cadavers and the Anatomage as adjunct teaching tools in undergraduate Anatomy and Physiology (A&P) students.MethodsIn collaboration with the Dallas Campus, the Anatomy Observational Outreach (AOO) stood to target undergraduate students from the Texas Woman's University (TWU) Denton Campus with interest in learning advanced human anatomy. There were 100 A&P laboratory students recruited for the AOO. After they took a 10 question pre‐test prior to the outreach, the students were allocated to smaller groups to observe human cadavers (group A) and the Anatomage (group B), guided by two Anatomy Professors, where they identified structures related to several anatomical systems. Students then answered post‐tests (identical to the pre‐tests) for the purpose of quantifying learning parameters to measure the success of prosection/anatomage. Finally, students were asked to respond to a 10 question feedback survey reporting their AOO experience.Results81% of participating students considered the undergraduate A&P courses to be lacking without the Anatomage, and believed the table to be an imperative tool in thoroughly learning and applying human anatomy. Moreover, 98% of the students increased in knowledge of extensive human anatomy.ConclusionIntegrating the Anatomage, the virtual dissection and anatomy table, into undergraduate A&P courses is paramount to the comprehensive learning and application of human anatomy in students' future health careers.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Learning Hepatobiliary Anatomy through the Virtual 3d Anatomy Table

ABSTRACT Objective to evaluate the effectiveness of the 3D virtual anatomical table as a complementary resource to the learning of the hepatobiliary anatomy by undergraduate medical students. Method A randomized controlled study comparing the anatomical learning of hepatobiliary structures, supported by a real model versus a virtual model, both three-dimensional (3D), by undergraduate medical students. The students’ perception of the resources used to teach anatomy was also evaluated. The students were submitted to a pre-test and to two evaluations after the interventions were applied. Results Overall, both the 3D virtual anatomical table and the real liver increased students’ knowledge of the hepatobiliary anatomy in relation to their previous knowledge (p = 0.001 and p = 0.01, respectively for second and third evaluations). In the longitudinal comparison between the pre-test and the second evaluation (hepatobiliary anatomy and Couinaud’s segmentation), this increase was significantly higher in the group allocated to the real liver (p = 0.002); in the comparison of the pre-test with the third evaluation (inclusion of adjacent organs in the anatomical table or in the real liver), the increase in knowledge was significantly higher in the group allocated to the anatomical table (p = 0.04). The perception of participants’ satisfaction regarding the learning resources was considered very good, with a minimum percentage of satisfaction of 80%. Conclusion the 3D virtual anatomical table provided more hepatobiliary anatomy knowledge than a real liver for undergraduate medical students, in comparison to their previous knowledge about these structures. In the cross-sectional comparison of the post-instruction evaluations, there was no difference between the two interventions. Moreover, the 3D platform had a positive impact on the level of satisfaction of study participants. This study shows that the 3D virtual anatomical table has the potential to improve both medical students’ understanding and interest in anatomy. It is recommended, however, that future protocols such as this be carried out with larger samples and exploring other anatomical structures.

Why Virtual Round Table

Why Virtual Round Table

EFFECTIVENESS OF THE DIGITAL IMAGE LIBRARY CASES IN HUMAN ANATOMY STUDIES

In several education technologies and options for teaching and studies one of the alternatives is the Anatomage 3D virtual dissection table with included Digital Image Library. The aim of this study was to observe the effectiveness of the Digital Image Library cases in Human Anatomy studies at Rīga Stradiņš University (RSU). In 2017 it was used every second week during the autumn`s practical classes on several occasions to show variety of interesting and many unique human anatomy cases, abnormalities, diseases and detailed sectional scans. As methods for collecting data were used discussions between students groups and survays. The sample included 100 students and 1 Human Anatomy tutor. The findings suggest that the Digital Image Library cases are very interactive and effective tools of the teaching and studies in Human Anatomy at RSU. This is a new form of the communication between students, tutor, virtual reality of the body systems and it provides a lot of digital materials that develop relationships between basic and clinical study subjects.

Turning the Virtual Tables: Government Strategies for Addressing Online Opposition with an Application to Russia

We introduce a novel classification of strategies employed by autocrats to combat hostile activity on the web and in social media in particular. Our classification looks at these options from the point of view of the end internet user and distinguishes both online from offline response and exerting control from engaging in opinion formation. For each of the three options – offline action, infrastructure regulation and online engagement – we provide a detailed account for the evolution of Russian government strategy since 2000. In addition, for online engagement option we construct the tools for detecting such activity on Twitter and test them on a large dataset of politically relevant Twitter data from ∗Corresponding author: sanovich@nyu.edu.

A robot-aided visuo-motor training that improves proprioception and spatial accuracy of untrained movement

Proprioceptive function can become enhanced during motor learning. Yet, we have incomplete knowledge to what extent proprioceptive function is trainable and how a training that enhances proprioception may influence performance in untrained motor skills. To address this knowledge gap, healthy young adults (N = 14) trained in a visuomotor task that required learners to make increasingly accurate wrist movements. Using a robotic exoskeleton coupled with a virtual visual environment, participants tilted a virtual table through continuous wrist flexion/extension movements with the goal to position a rolling ball on table into a target. With learning progress, the level of difficulty increased by altering the virtual ball mechanics and the gain between joint movement and ball velocity. Before and after training, wrist position sense acuity and spatial movement accuracy in an untrained, discrete wrist-pointing task was assessed using the same robot. All participants showed evidence of proprioceptive-motor learning. Mean position sense discrimination threshold improved by 34%. Wrist movement accuracy in the untrained pointing task improved by 27% in 13/14 participants. This demonstrates that a short sensorimotor training challenging proprioception can a) effectively enhance proprioceptive acuity and b) improve the accuracy of untrained movement. These findings provide a scientific basis for applying such somatosensory-based motor training to clinical populations with known proprioceptive dysfunction to enhance sensorimotor performance.

SAVI objects: sharing and virtuality incorporated

Direct sharing and storing of memory objects allows high-performance and low-overhead collaboration between parallel processes or application workflows with loosely coupled programs. However, sharing of objects is hindered by the inability to use subtype polymorphism which is common in object-oriented programming languages. That is because implementations of subtype polymorphism in modern compilers rely on using virtual tables stored at process-specific locations, which makes objects unusable in processes other than the creating process. In this paper, we present SAVI Objects, objects with Sharing and Virtuality Incorporated. SAVI Objects support subtype polymorphism but can still be shared across processes and stored in persistent data structures. We propose two different techniques to implement SAVI Objects and evaluate the tradeoffs between them. The first technique is virtual table duplication which adheres to the virtual-table-based implementation of subtype polymorphism, but duplicates virtual tables for shared objects to fixed memory addresses associated with each shared memory region. The second technique is hashing-based dynamic dispatch which re-implements subtype polymorphism using hashing-based look-ups to a global virtual table. Our results show that SAVI Objects enable direct sharing and storing of memory objects that use subtype polymorphism by adding modest overhead costs to object construction and dynamic dispatch time. SAVI Objects thus enable faster inter-process communication, improving the overall performance of production applications that share polymorphic objects.

Development of a Virtual Multi-Axial Simulation Table to Enhance the Prognosis of Loads on Powertrain Mounting System During Durability Applications

Development of a Virtual Multi-Axial Simulation Table to Enhance the Prognosis of Loads on Powertrain Mounting System During Durability Applications

The Virtual Table: A Framework for Online Teamwork, Collaboration, and Communication.

This chapter reviews the complex relationship between technology and leadership, focusing on how technology affects the development and demonstration of skills in communication, teamwork, and collaboration. The chapter also proposes a framework for identifying and assessing key leadership competencies in the digital space.

Student learning performance in human anatomy using a virtual dissection table

In medical training it is fundamental to have a 3D understanding of human anatomy [1]. Body dissection is considered mandatory in most of the bio-medical schools. Medical schools around the world, constantly face the problem of availability of the cadavers. Apart from the classic methods (lectures, podcasts, atlas or photographs, models) technology advances made available new instruments to learn/teach 3D anatomy, which allow cadaverless dissection with the help of simulator software or virtual cadavers. The Anatomage® and Sectra® tables are advanced anatomy visualization systems, adopted by many of the world’s leading medical schools and institutions [2,3]. Here we report our experience with Anatomage® during the Academic Year 2016-17, in the Postgraduate Courses of Medical and Surgical Specialization, Master degrees in Medicine, Dental Medicine, Biology of Health and Nutrition, as well as Basic Degrees in Nursing and Biotechnology, of the University of L’Aquila. We enrolled 30 MD postgraduate students, and 440 undergraduate students. Both postgraduate and undergraduate medical students were allowed to handle the table. The other students assisted to class table demonstrations. An evaluation test was administered to all students at the end of the Courses. Our preliminary observations suggest that the use of virtual dissection table into the anatomical curriculum improves the learning student performance. Each student have a different set of needs, and the base line skills may be different. So, the teacher should take in consideration the variable scope of practice of the specific health professions. We are currently evaluating the efficacy of this technology at the end of the examinations. In the present preliminary report, we account with our results that are indicative of a positive impact on both basic and advanced anatomical learning.

Speech intelligibility in virtual restaurants.

Speech reception thresholds (SRTs) for a target voice on the same virtual table were measured in various restaurant simulations under conditions of masking by between one and eight interferers at other tables. Results for different levels of reverberation and different simulation techniques were qualitatively similar. SRTs increased steeply with the number of interferers, reflecting progressive failure to perceptually unmask the target speech as the acoustic scene became more complex. For a single interferer, continuous noise was the most effective masker, and a single interfering voice of either gender was least effective. With two interferers, evidence of informational masking emerged as a difference in SRT between forward and reversed speech, but SRTs for all interferer types progressively converged at four and eight interferers. In simulation based on a real room, this occurred at a signal-to-noise ratio of around -5 dB.

Abiding Chance: Online Poker and the Software of Self-Discipline

Online poker gamblers employ software to track and algorithmically analyze play-by-play game information in real time, parsing opponents’ behavioral patterns and tendencies into color-coded numerical values that hover over their respective positions at the virtual table. These continuously updated statistical dashboards, along with retrospective game analysis and methodical routines of self-adjustment, help gamblers abide swings of chance and avoid falling into the emotionally clouded, fiscally dangerous state of “tilt.” Drawing on interviews with gamblers, observations of online poker play, and discussion threads from poker forum archives, the article explores how the game and its data-intensive software teach gamblers to act from the vantage of an infinite temporal field in which probabilistic values can be trusted to bear out. Although digital media is often associated with choice paralysis and the disappearance of the subject, here it serves as a technology of the self. The composure toward chance events that gamblers cultivate online carries over to their lives off-line, lending them a subjective “readiness” for living with uncertainty. The case of online poker offers a window onto broader predicaments of choice making under conditions of heightened economic volatility.

A novel data storage logic in the cloud.

Databases which store and manage long-term scientific information related to life science are used to store huge amount of quantitative attributes. Introduction of a new entity attribute requires modification of the existing data tables and the programs that use these data tables. The solution is increasing the virtual data tables while the number of screens remains the same. The main objective of the present study was to introduce a logic called Joker Tao (JT) which provides universal data storage for cloud-based databases. It means all types of input data can be interpreted as an entity and attribute at the same time, in the same data table.

A novel data storage logic in the cloud

Databases which store and manage long-term scientific information related to lifescience are used to store huge amounts of quantitative attributes. Introduction ofa new entity attribute requires modification of the existing data tables and the programsthat use these data tables. The solution is increasing the virtual data tableswhile the number of screens remains the same. The main objective of the presentstudy was to introduce a logic called Joker Tao (JT) which provides universal datastorage for cloud-based databases. It means all types of input data can be interpretedas an entity and attribute at the same time, in the same data table.

Buffer overflow vulnerabilities in CUDA: a preliminary analysis

We present a preliminary study of buffer overflow vulnerabilities in CUDA software running on GPUs. We show how an attacker can overrun a buffer to corrupt sensitive data or steer the execution flow by overwriting function pointers, e.g., manipulating the virtual table of a C++ object. In view of a potential mass market diffusion of GPU accelerated software this may be a major concern.

실행시간 침입 방지 평가 프로그램(RIPE)의 개선

Runtime Intrusion Prevention Evaluator (RIPE), published in 2011, is a benchmark suite for evaluating mitigation techniques against 850 attack patterns using only buffer overflow. Since RIPE is built as a single process, defense and attack routines cannot help sharing process states and address space layouts when RIPE is tested. As a result, attack routines can access the memory space for defense routines without restriction. We separate RIPE into two independent processes of defense and attacks so that mitigations based on confidentiality such as address space layout randomization are properly evaluated. In addition, we add an execution mode to test robustness against brute force attacks. Finally, we extend RIPE by adding 38 attack forms to perform format string attacks and virtual table (vtable) hijacking attacks. The revised RIPE contributes to the diversification of attack patterns and precise evaluation of the effectiveness of mitigations.