Pub Date : 2021-09-18DOI: 10.1177/15485129211047598
Ravi Shankar, Patteti Krishna, Naraiah R
With the tremendous increase in wireless user traffic, investigation on the end-to-end reliability of wireless networks in practical conditions such as non-homogeneous fading channel conditions is becoming increasingly widespread. Because they fit well to the experimental data, generalized channel fading distributions like κ–μ are well suited for modeling diverse fading channels. This paper analyzes the symbol error rate (SER) and outage probability (OP) performance of multiple-input multiple-output (MIMO) space-time block-code (STBC) selective decode and forward (S-DF) network over κ–μ fading channel conditions considering the additive white Gaussian noise (AWGN). First, the closed-form (CF) analytical expressions for the probability density function (PDF) and the cumulative distribution function (CDF) of the received signal-to-noise ratio (SNR) as well as its moment generating function (MGF) are derived. Second, the OP performance is then investigated for various values of the channel fading parameter and SNR regimes. The simulation findings show an increase in SER performance with an improved line-of-sight (LOS) component. Furthermore, the results show that the S-DF relaying systems can function properly even when there is no fading or LOS component. The OP has been increasing with the increase in the value of μ and κ. In medium and high SNR regimes, simulation results exactly match with analytical results.
{"title":"Examination of the multiple-input multiple-output space-time block-code selective decode and forward relaying protocol over non-homogeneous fading channel conditions","authors":"Ravi Shankar, Patteti Krishna, Naraiah R","doi":"10.1177/15485129211047598","DOIUrl":"https://doi.org/10.1177/15485129211047598","url":null,"abstract":"With the tremendous increase in wireless user traffic, investigation on the end-to-end reliability of wireless networks in practical conditions such as non-homogeneous fading channel conditions is becoming increasingly widespread. Because they fit well to the experimental data, generalized channel fading distributions like κ–μ are well suited for modeling diverse fading channels. This paper analyzes the symbol error rate (SER) and outage probability (OP) performance of multiple-input multiple-output (MIMO) space-time block-code (STBC) selective decode and forward (S-DF) network over κ–μ fading channel conditions considering the additive white Gaussian noise (AWGN). First, the closed-form (CF) analytical expressions for the probability density function (PDF) and the cumulative distribution function (CDF) of the received signal-to-noise ratio (SNR) as well as its moment generating function (MGF) are derived. Second, the OP performance is then investigated for various values of the channel fading parameter and SNR regimes. The simulation findings show an increase in SER performance with an improved line-of-sight (LOS) component. Furthermore, the results show that the S-DF relaying systems can function properly even when there is no fading or LOS component. The OP has been increasing with the increase in the value of μ and κ. In medium and high SNR regimes, simulation results exactly match with analytical results.","PeriodicalId":44661,"journal":{"name":"Journal of Defense Modeling and Simulation-Applications Methodology Technology-JDMS","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82778754","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 : 2021-09-13DOI: 10.1177/15485129211040379
Aron Wing, Tony Liu, A. Palazotto
The purpose of this work is to analyze the heat transfer characteristics of Vascomax®C300 during high-speed sliding. This work extends previous research that is intended to help predict the wear-rate of connecting shoes for a hypersonic rail system at Holloman Air Force Base to prevent critical failure of the system. Solutions were generated using finite element analysis and spectral methods. The frictional heat generated by the pin-on-disk is assumed to flow uniformly and normal to the face of the pin and the pin is assumed to be a perfect cylinder resulting in two-dimensional heat flow. Displacement data obtained from the experiment is used to define the moving boundary. The distribution of temperature resulting from transient finite element analysis is used to justify a one-dimensional model. Spectral methods are then employed to calculate the spatial derivatives improving the approximation of the function which represents the data. It is concluded that a one-dimensional approach with constant heat transfer parameters sufficiently models the high-speed pin-on-disk experiment.
{"title":"Modeling a high-speed pin-on-disk experiment","authors":"Aron Wing, Tony Liu, A. Palazotto","doi":"10.1177/15485129211040379","DOIUrl":"https://doi.org/10.1177/15485129211040379","url":null,"abstract":"The purpose of this work is to analyze the heat transfer characteristics of Vascomax®C300 during high-speed sliding. This work extends previous research that is intended to help predict the wear-rate of connecting shoes for a hypersonic rail system at Holloman Air Force Base to prevent critical failure of the system. Solutions were generated using finite element analysis and spectral methods. The frictional heat generated by the pin-on-disk is assumed to flow uniformly and normal to the face of the pin and the pin is assumed to be a perfect cylinder resulting in two-dimensional heat flow. Displacement data obtained from the experiment is used to define the moving boundary. The distribution of temperature resulting from transient finite element analysis is used to justify a one-dimensional model. Spectral methods are then employed to calculate the spatial derivatives improving the approximation of the function which represents the data. It is concluded that a one-dimensional approach with constant heat transfer parameters sufficiently models the high-speed pin-on-disk experiment.","PeriodicalId":44661,"journal":{"name":"Journal of Defense Modeling and Simulation-Applications Methodology Technology-JDMS","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86793521","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 : 2021-09-06DOI: 10.1177/15485129211040782
Nathaniel Choo, D. Ahner, L. Champagne
Long-duration logistical wargames within the Air domain are complex and highly dynamic events that are driven by aircraft availability. In order to gain insight into the impact of aircraft use, this research developed a simulation tool that uses a stepwise approach for adjudication and provides the user many capabilities including, but not limited to, the ability to have multiple bases and types of aircraft. Daily aircraft availability and missions accomplished are two critical metrics of interest. Within the simulation, the user has the ability to control types of part failures, control parts availability, control maintenance capabilities, and control number of mission scheduled. Finally, the user can account for the possibility of attrition along with the effects of numerous major events present in real-life scenarios. This tool is validated through application of a space covering design along with regression modeling and shows that the tool is well-behaved, functions as expected, and can quickly provide meaningful insights into operational scenarios.
{"title":"The effects of aircraft use and available repair spares on aircraft sortie generation: a long-duration logistical wargaming simulation tool","authors":"Nathaniel Choo, D. Ahner, L. Champagne","doi":"10.1177/15485129211040782","DOIUrl":"https://doi.org/10.1177/15485129211040782","url":null,"abstract":"Long-duration logistical wargames within the Air domain are complex and highly dynamic events that are driven by aircraft availability. In order to gain insight into the impact of aircraft use, this research developed a simulation tool that uses a stepwise approach for adjudication and provides the user many capabilities including, but not limited to, the ability to have multiple bases and types of aircraft. Daily aircraft availability and missions accomplished are two critical metrics of interest. Within the simulation, the user has the ability to control types of part failures, control parts availability, control maintenance capabilities, and control number of mission scheduled. Finally, the user can account for the possibility of attrition along with the effects of numerous major events present in real-life scenarios. This tool is validated through application of a space covering design along with regression modeling and shows that the tool is well-behaved, functions as expected, and can quickly provide meaningful insights into operational scenarios.","PeriodicalId":44661,"journal":{"name":"Journal of Defense Modeling and Simulation-Applications Methodology Technology-JDMS","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88390734","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 : 2021-08-31DOI: 10.1177/15485129211033038
Dionysios Tompros, D. Mouzakis
The space environment is extremely hostile to the spacecraft but also to the equipment it carries. The materials which are used to the external side of the spacecraft, the solar panels, the sensors, and the electronics circuits, suffer greatly from their exposure to it. Extreme temperatures, ultraviolet radiation, ionizing radiation from solar proton events and cosmic rays, atomic oxygen in LEO, as well as collisions with micrometeoroids and space debris are factors that degrade the stuff, multiply the mission cost, and increase the risk. Therefore, the state-of-art of material technology is needed. In this study, a set of materials and technologies are presented, which reduce the above-mentioned risks. Extreme temperatures, ultra-vacuum, atomic oxygen, and high-energy radiation including particles as well as energy sources (X- and gamma rays) are potential extreme exposure conditions. Testing and qualification of materials exposed to these extreme conditions is a difficult task, to enable the design and manufacturing of high-endurance reliable components to be used in the world’s most sophisticated satellite and spacecraft components, as well as in future endeavors into the vicinity of the Solar System.
{"title":"Space environment effects on equipment and structures—current and future technologies","authors":"Dionysios Tompros, D. Mouzakis","doi":"10.1177/15485129211033038","DOIUrl":"https://doi.org/10.1177/15485129211033038","url":null,"abstract":"The space environment is extremely hostile to the spacecraft but also to the equipment it carries. The materials which are used to the external side of the spacecraft, the solar panels, the sensors, and the electronics circuits, suffer greatly from their exposure to it. Extreme temperatures, ultraviolet radiation, ionizing radiation from solar proton events and cosmic rays, atomic oxygen in LEO, as well as collisions with micrometeoroids and space debris are factors that degrade the stuff, multiply the mission cost, and increase the risk. Therefore, the state-of-art of material technology is needed. In this study, a set of materials and technologies are presented, which reduce the above-mentioned risks. Extreme temperatures, ultra-vacuum, atomic oxygen, and high-energy radiation including particles as well as energy sources (X- and gamma rays) are potential extreme exposure conditions. Testing and qualification of materials exposed to these extreme conditions is a difficult task, to enable the design and manufacturing of high-endurance reliable components to be used in the world’s most sophisticated satellite and spacecraft components, as well as in future endeavors into the vicinity of the Solar System.","PeriodicalId":44661,"journal":{"name":"Journal of Defense Modeling and Simulation-Applications Methodology Technology-JDMS","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80944520","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 : 2021-08-27DOI: 10.1177/15485129211041963
D. Tryhorn, Richard Dill, D. Hodson, M. Grimaila, Christopher W. Myers
This research identifies specific communication sensor features vulnerable to fog and provides a method to introduce them into an Advanced Framework for Simulation, Integration, and Modeling (AFSIM) wargame scenario. Military leaders use multiple information sources about the battlespace to make timely decisions that advance their operational objectives while attempting to deny their opponent’s actions. Unfortunately, the complexities of battle combined with uncertainty in situational awareness of the battlespace, too much or too little intelligence, and the opponent’s intentional interference with friendly command and control actions yield an abstract layer of battlespace fog. Decision-makers must understand, characterize and overcome this “battlespace fog” to accomplish operational objectives. This research proposes a novel tool, the Fog Analysis Tool (FAT), to automatically compile a list of communication and sensor objects within a scenario and list options that may impact decision-making processes. FAT improves wargame realism by introducing and standardizing fog levels across communication links and sensor feeds in an AFSIM scenario. Research results confirm that FAT provides significant benefits and enables the measurement of fog impacts to tactical command and control decisions within AFSIM scenarios.
{"title":"Modeling fog of war effects in AFSIM","authors":"D. Tryhorn, Richard Dill, D. Hodson, M. Grimaila, Christopher W. Myers","doi":"10.1177/15485129211041963","DOIUrl":"https://doi.org/10.1177/15485129211041963","url":null,"abstract":"This research identifies specific communication sensor features vulnerable to fog and provides a method to introduce them into an Advanced Framework for Simulation, Integration, and Modeling (AFSIM) wargame scenario. Military leaders use multiple information sources about the battlespace to make timely decisions that advance their operational objectives while attempting to deny their opponent’s actions. Unfortunately, the complexities of battle combined with uncertainty in situational awareness of the battlespace, too much or too little intelligence, and the opponent’s intentional interference with friendly command and control actions yield an abstract layer of battlespace fog. Decision-makers must understand, characterize and overcome this “battlespace fog” to accomplish operational objectives. This research proposes a novel tool, the Fog Analysis Tool (FAT), to automatically compile a list of communication and sensor objects within a scenario and list options that may impact decision-making processes. FAT improves wargame realism by introducing and standardizing fog levels across communication links and sensor feeds in an AFSIM scenario. Research results confirm that FAT provides significant benefits and enables the measurement of fog impacts to tactical command and control decisions within AFSIM scenarios.","PeriodicalId":44661,"journal":{"name":"Journal of Defense Modeling and Simulation-Applications Methodology Technology-JDMS","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87510952","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 : 2021-08-27DOI: 10.1177/15485129211040369
M. Hocaoğlu
Threat evaluation is a vital process for any defense system, and it consists of a series of calculation and evaluation based on the inferred capabilities and intents of the targets that aim to give damage to defended assets. Target evaluation is proceeded in a wargame and the aim is to compare weapon target pairs according to a set of criteria. The target evaluation cycle is repeated anytime a new detection is received and when any change happens in the target currently detected. The whole process consists of a set of tasks that are shared between Command and Control units and the tasks require different responsibilities. Each task is succeeded by a specific behavior that is represented as a reasonably ordered set of actions. The task sharing is organized by taking the C2 architectures into account. In this paper, an agent-based command and control entity, which is in charge of target evaluation and giving engagement decision, is designed and it is situated in an air defense simulation environment. The study aims to propose an agent design in military decision-making domain, bringing analytic methods with the first-order logic together, and combine aspect orientation with agent design. The study also improves dynamic aspect management in agent programming using the relation concept.
{"title":"Agent-based target evaluation and fire doctrine: an aspect-oriented programming view","authors":"M. Hocaoğlu","doi":"10.1177/15485129211040369","DOIUrl":"https://doi.org/10.1177/15485129211040369","url":null,"abstract":"Threat evaluation is a vital process for any defense system, and it consists of a series of calculation and evaluation based on the inferred capabilities and intents of the targets that aim to give damage to defended assets. Target evaluation is proceeded in a wargame and the aim is to compare weapon target pairs according to a set of criteria. The target evaluation cycle is repeated anytime a new detection is received and when any change happens in the target currently detected. The whole process consists of a set of tasks that are shared between Command and Control units and the tasks require different responsibilities. Each task is succeeded by a specific behavior that is represented as a reasonably ordered set of actions. The task sharing is organized by taking the C2 architectures into account. In this paper, an agent-based command and control entity, which is in charge of target evaluation and giving engagement decision, is designed and it is situated in an air defense simulation environment. The study aims to propose an agent design in military decision-making domain, bringing analytic methods with the first-order logic together, and combine aspect orientation with agent design. The study also improves dynamic aspect management in agent programming using the relation concept.","PeriodicalId":44661,"journal":{"name":"Journal of Defense Modeling and Simulation-Applications Methodology Technology-JDMS","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72571929","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}
Ensuring the secure communication is the prime concern for all kinds of data communication infrastructure. Several data encryption techniques are in use for secure communication. There is a scope for further improvement in the security level, as well as for the received signal quality. The selection of a proper combination of encryption and modulation techniques can improve the overall effectiveness of both the security level and the received signal quality. The combination of asymmetric cryptography (here use RSA (Rivest–Shamir–Adleman) algorithm) algorithm with the proposed reflex klystron-based frequency shift keying (FSK) modulation technique provides a high level of secure communication system. The performance of the proposed technique is experimentally verified. The conventional FSK modulation technique operates in the low-frequency band, but the proposed FSK modulation technique is powered by high-power microwave devices, which operate in the X band. The experimental result has been demonstrated and successfully verified for secured communication using the X band.
{"title":"RSA encrypted FSK RF transmission powered by an innovative microwave technique for invulnerable security","authors":"Prashnatita Pal, Bikash Chandra Sahana, Jayanta Poray","doi":"10.1177/15485129211031670","DOIUrl":"https://doi.org/10.1177/15485129211031670","url":null,"abstract":"Ensuring the secure communication is the prime concern for all kinds of data communication infrastructure. Several data encryption techniques are in use for secure communication. There is a scope for further improvement in the security level, as well as for the received signal quality. The selection of a proper combination of encryption and modulation techniques can improve the overall effectiveness of both the security level and the received signal quality. The combination of asymmetric cryptography (here use RSA (Rivest–Shamir–Adleman) algorithm) algorithm with the proposed reflex klystron-based frequency shift keying (FSK) modulation technique provides a high level of secure communication system. The performance of the proposed technique is experimentally verified. The conventional FSK modulation technique operates in the low-frequency band, but the proposed FSK modulation technique is powered by high-power microwave devices, which operate in the X band. The experimental result has been demonstrated and successfully verified for secured communication using the X band.","PeriodicalId":44661,"journal":{"name":"Journal of Defense Modeling and Simulation-Applications Methodology Technology-JDMS","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79949066","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 : 2021-08-18DOI: 10.1177/15485129211040373
Jan Drozd, L. Rak, P. Zahradníček, P. Stodola, J. Hodický
The paper sets out the results of an experiment carried out using MASA SWORD simulator to verify the use of the unmanned aerial vehicle (UAV) reconnaissance model during battalion force protection activities. The authors focus particularly on the first phase of the battle—enemy approaching and early reconnaissance. The reconnaissance was planned using the UAV reconnaissance model which is part of the Tactical Decision Support System (TDSS). The aim of the experiment is to verify the possibilities of using the UAV reconnaissance model for battalion-size unit force protection and to compare this model with ordinarily used tactical procedures. The experiment proves the hypothesis defined in the introduction and quantifies some defined variables. Based on the result of the experiment, it is possible to state that UAV reconnaissance has significant impact on the effectiveness of the military mission. Moreover, the simulation environment opens a wide range of possibilities for future research including multiple simulations of the scenario, comparison of achieved results in dependence on the set conditions and variable settings, tailoring tactics for the scenario at hand, and so on.
{"title":"Effectiveness evaluation of aerial reconnaissance in battalion force protection operation using the constructive simulation","authors":"Jan Drozd, L. Rak, P. Zahradníček, P. Stodola, J. Hodický","doi":"10.1177/15485129211040373","DOIUrl":"https://doi.org/10.1177/15485129211040373","url":null,"abstract":"The paper sets out the results of an experiment carried out using MASA SWORD simulator to verify the use of the unmanned aerial vehicle (UAV) reconnaissance model during battalion force protection activities. The authors focus particularly on the first phase of the battle—enemy approaching and early reconnaissance. The reconnaissance was planned using the UAV reconnaissance model which is part of the Tactical Decision Support System (TDSS). The aim of the experiment is to verify the possibilities of using the UAV reconnaissance model for battalion-size unit force protection and to compare this model with ordinarily used tactical procedures. The experiment proves the hypothesis defined in the introduction and quantifies some defined variables. Based on the result of the experiment, it is possible to state that UAV reconnaissance has significant impact on the effectiveness of the military mission. Moreover, the simulation environment opens a wide range of possibilities for future research including multiple simulations of the scenario, comparison of achieved results in dependence on the set conditions and variable settings, tailoring tactics for the scenario at hand, and so on.","PeriodicalId":44661,"journal":{"name":"Journal of Defense Modeling and Simulation-Applications Methodology Technology-JDMS","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72384411","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 : 2021-08-18DOI: 10.1177/15485129211036936
M. Coovert, Winston Bennett
Advances at the intersection of artificial intelligence (AI) and education and training are occurring at an ever-increasing pace. On the education and training side, psychological and performance constructs play a central role in both theory and application. It is essential, therefore, to accurately determine the dimensionality of a construct, as it is often employed during both the assessment and development of theory, and its practical application. Traditionally, both exploratory and confirmatory factor analyses have been employed to establish the dimensionality of data. Due in part to inconsistent findings, methodologists recently resurrected the bifactor approach for establishing the dimensionality of data. The bifactor model is pitted against traditional data structures, and the one with the best overall fit (according to chi-square, root mean square error of approximation (RMSEA), comparative fit index (CFI), Tucker–Lewis index (TLI), and standardized root mean square residual (SRMR)) is preferred. If the bifactor structure is preferred by that test, it can be further examined via a suite of emerging coefficients (e.g., omega, omega hierarchical, omega subscale, H, explained common variance, and percent uncontaminated correlations), each of which is computed from standardized factor loadings. To examine the utility of these new statistical tools in an education and training context, we analyze data where the construct of interest is trust. We chose trust as it is central, among other things, to understanding human reliance upon and utilization of AI systems. We utilized the above statistical approach and determined the two-factor structure of widely employed trust scale is better represented by one general factor. Findings like this hold substantial implications for theory development and testing, prediction as in structural equation modeling (SEM) models, as well as the utilization of scales and their role in education, training, and AI systems. We encourage other researchers to employ the statistical measures described here to critically examine the construct measures used in their work if those measures are thought to be multidimensional. Only through the appropriate utilization of constructs, defined in part by their dimensionality, are we to advance the intersection of AI and simulation and training.
{"title":"The importance of identifying the dimensionality of constructs employed in simulation and training for AI","authors":"M. Coovert, Winston Bennett","doi":"10.1177/15485129211036936","DOIUrl":"https://doi.org/10.1177/15485129211036936","url":null,"abstract":"Advances at the intersection of artificial intelligence (AI) and education and training are occurring at an ever-increasing pace. On the education and training side, psychological and performance constructs play a central role in both theory and application. It is essential, therefore, to accurately determine the dimensionality of a construct, as it is often employed during both the assessment and development of theory, and its practical application. Traditionally, both exploratory and confirmatory factor analyses have been employed to establish the dimensionality of data. Due in part to inconsistent findings, methodologists recently resurrected the bifactor approach for establishing the dimensionality of data. The bifactor model is pitted against traditional data structures, and the one with the best overall fit (according to chi-square, root mean square error of approximation (RMSEA), comparative fit index (CFI), Tucker–Lewis index (TLI), and standardized root mean square residual (SRMR)) is preferred. If the bifactor structure is preferred by that test, it can be further examined via a suite of emerging coefficients (e.g., omega, omega hierarchical, omega subscale, H, explained common variance, and percent uncontaminated correlations), each of which is computed from standardized factor loadings. To examine the utility of these new statistical tools in an education and training context, we analyze data where the construct of interest is trust. We chose trust as it is central, among other things, to understanding human reliance upon and utilization of AI systems. We utilized the above statistical approach and determined the two-factor structure of widely employed trust scale is better represented by one general factor. Findings like this hold substantial implications for theory development and testing, prediction as in structural equation modeling (SEM) models, as well as the utilization of scales and their role in education, training, and AI systems. We encourage other researchers to employ the statistical measures described here to critically examine the construct measures used in their work if those measures are thought to be multidimensional. Only through the appropriate utilization of constructs, defined in part by their dimensionality, are we to advance the intersection of AI and simulation and training.","PeriodicalId":44661,"journal":{"name":"Journal of Defense Modeling and Simulation-Applications Methodology Technology-JDMS","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85295807","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 : 2021-08-18DOI: 10.1177/15485129211036937
Júlio Mendonça, Jin-Hee Cho, T. Moore, Frederica F. Nelson, Hyuk Lim, Dan Dongseong Kim
Moving target defense (MTD) is a promising proactive defense technique to enhance system or network security. One caveat in developing a time-based MTD-enabled system is the potential performance degradation due to MTD operations being triggered periodically. In this work, we present our developed stochastic models based on deterministic stochastic Petri net (DSPN) formalism to assess the performance degradation introduced by periodic MTD operations. In addition, we demonstrate the effect of triggering a time-based MTD operation on performance degradation (e.g., jobs dropped or response time) and quality-of-service (QoS) of the system. We conducted comparative performance analysis with five DSPN models implemented in software packages such as TimeNet and Mercury under five different system configuration scenarios. Our key findings from this study include the following: (1) the deployment of MTD with the switchover strategy can improve the performance of services; (2) the switchover strategy showed the best cost-effectiveness among all strategies considered in this work; and (3) the interval of triggering MTD operations introduced a modest impact on job completion probability.
{"title":"Performance impact analysis of services under a time-based moving target defense mechanism","authors":"Júlio Mendonça, Jin-Hee Cho, T. Moore, Frederica F. Nelson, Hyuk Lim, Dan Dongseong Kim","doi":"10.1177/15485129211036937","DOIUrl":"https://doi.org/10.1177/15485129211036937","url":null,"abstract":"Moving target defense (MTD) is a promising proactive defense technique to enhance system or network security. One caveat in developing a time-based MTD-enabled system is the potential performance degradation due to MTD operations being triggered periodically. In this work, we present our developed stochastic models based on deterministic stochastic Petri net (DSPN) formalism to assess the performance degradation introduced by periodic MTD operations. In addition, we demonstrate the effect of triggering a time-based MTD operation on performance degradation (e.g., jobs dropped or response time) and quality-of-service (QoS) of the system. We conducted comparative performance analysis with five DSPN models implemented in software packages such as TimeNet and Mercury under five different system configuration scenarios. Our key findings from this study include the following: (1) the deployment of MTD with the switchover strategy can improve the performance of services; (2) the switchover strategy showed the best cost-effectiveness among all strategies considered in this work; and (3) the interval of triggering MTD operations introduced a modest impact on job completion probability.","PeriodicalId":44661,"journal":{"name":"Journal of Defense Modeling and Simulation-Applications Methodology Technology-JDMS","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90073798","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}
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