Pub Date : 2023-06-30DOI: 10.3390/inventions8040086
Peyman Mousavi, M. Ghazizadeh, V. Vahidinasab
Despite the fact that power grids have been planned and utilized using centralized networks for many years, there are now significant changes occurring as a result of the growing number of distributed energy resources, the development of energy storage systems and devices, and the increased use of electric vehicles. In light of this development, it is pertinent to ask what an efficient approach would be to the operation and management of future distribution grids consisting of millions of distributed and even mobile energy elements. Parallel to this evolution in power grids, there has been rapid growth in decentralized management technology due to the development of relevant technologies such as blockchain networks. Blockchain is an advanced technology that enables us to answer the question raised above. This paper introduces a decentralized blockchain network based on the Hyperledger Fabric framework. The proposed framework enables the formation of local energy markets of future citizen energy communities (CECs) through peer-to-peer transactions. In addition, it is designed to ensure adequate load supply and observe the network’s constraints while running an optimal operation point by consensus among all of the players in a CEC. An open-source tool in Python is used to verify the performance of the proposed framework and compare the results. Through its distributed and layered management structure, the proposed blockchain-based framework proves its superior flexibility and proper functioning. Moreover, the results show that the proposed model increases system performance, reduces costs, and reaches an operating point based on consensus among the microgrid elements.
{"title":"A Decentralized Blockchain-Based Energy Market for Citizen Energy Communities","authors":"Peyman Mousavi, M. Ghazizadeh, V. Vahidinasab","doi":"10.3390/inventions8040086","DOIUrl":"https://doi.org/10.3390/inventions8040086","url":null,"abstract":"Despite the fact that power grids have been planned and utilized using centralized networks for many years, there are now significant changes occurring as a result of the growing number of distributed energy resources, the development of energy storage systems and devices, and the increased use of electric vehicles. In light of this development, it is pertinent to ask what an efficient approach would be to the operation and management of future distribution grids consisting of millions of distributed and even mobile energy elements. Parallel to this evolution in power grids, there has been rapid growth in decentralized management technology due to the development of relevant technologies such as blockchain networks. Blockchain is an advanced technology that enables us to answer the question raised above. This paper introduces a decentralized blockchain network based on the Hyperledger Fabric framework. The proposed framework enables the formation of local energy markets of future citizen energy communities (CECs) through peer-to-peer transactions. In addition, it is designed to ensure adequate load supply and observe the network’s constraints while running an optimal operation point by consensus among all of the players in a CEC. An open-source tool in Python is used to verify the performance of the proposed framework and compare the results. Through its distributed and layered management structure, the proposed blockchain-based framework proves its superior flexibility and proper functioning. Moreover, the results show that the proposed model increases system performance, reduces costs, and reaches an operating point based on consensus among the microgrid elements.","PeriodicalId":14564,"journal":{"name":"Inventions","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49218975","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 : 2023-06-30DOI: 10.3390/inventions8040085
S. Taraman, Amy Moss, Hieu Le, Lois Sayrs, Tianyi Li
Tremors affect pediatric and adult populations, with roughly 3% of people worldwide experiencing essential tremors. Treatments include medication, deep brain stimulation, occupational/physical therapy, or adaptive equipment. This unblinded experimental pre-test–post-test study was performed (April–September 2021) at Children’s Health of Orange County, evaluating the effectiveness of Move-D, a novel orthotic brace, on pediatric tremors. Ten participants (14–19 years old) experiencing upper extremity tremors (5 essential, 2 dystonic, 1 coarse, 1 postural, and 1 unspecified) were enrolled. Participants completed a usability survey and performance was measured utilizing the Bruininks–Oseretsky Test of Motor Proficiency, second edition, with and without the brace, using one-sided t-tests of mean differences. Move-D improved age-equivalent scores for fine motor precision by 20.5 months and upper limb coordination by 15.1 months. Manual coordination percentile rankings increased by 2.9%. Manual dexterity performance was unaffected. The usability survey revealed that 7/10 participants agreed or strongly agreed that they could move their arm freely while wearing the brace, the brace reduced their tremors, and they felt comfortable wearing the brace at home. Through standardized testing and findings from the usability survey, Move-D showed an improvement of functional abilities in a pediatric population with tremors.
{"title":"Investigative and Usability Findings of the Move-D Orthotic Brace Prototype for Upper Extremity Tremors in Pediatric Patients: An Unblinded, Experimental Study","authors":"S. Taraman, Amy Moss, Hieu Le, Lois Sayrs, Tianyi Li","doi":"10.3390/inventions8040085","DOIUrl":"https://doi.org/10.3390/inventions8040085","url":null,"abstract":"Tremors affect pediatric and adult populations, with roughly 3% of people worldwide experiencing essential tremors. Treatments include medication, deep brain stimulation, occupational/physical therapy, or adaptive equipment. This unblinded experimental pre-test–post-test study was performed (April–September 2021) at Children’s Health of Orange County, evaluating the effectiveness of Move-D, a novel orthotic brace, on pediatric tremors. Ten participants (14–19 years old) experiencing upper extremity tremors (5 essential, 2 dystonic, 1 coarse, 1 postural, and 1 unspecified) were enrolled. Participants completed a usability survey and performance was measured utilizing the Bruininks–Oseretsky Test of Motor Proficiency, second edition, with and without the brace, using one-sided t-tests of mean differences. Move-D improved age-equivalent scores for fine motor precision by 20.5 months and upper limb coordination by 15.1 months. Manual coordination percentile rankings increased by 2.9%. Manual dexterity performance was unaffected. The usability survey revealed that 7/10 participants agreed or strongly agreed that they could move their arm freely while wearing the brace, the brace reduced their tremors, and they felt comfortable wearing the brace at home. Through standardized testing and findings from the usability survey, Move-D showed an improvement of functional abilities in a pediatric population with tremors.","PeriodicalId":14564,"journal":{"name":"Inventions","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47143649","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 : 2023-06-29DOI: 10.3390/inventions8040083
Yu-Yen Chen, Pi-Chung Wang
The deployment of vehicular ad hoc network (VANET) is crucial to the development of autonomous vehicles. Radio frequency (RF) technology has been employed to transmit messages between vehicles and infrastructure in VANET. However, the limited RF bands may cause interference when vehicles transmit messages in a high-density environment. Moreover, when numerous vehicles transmit messages to the infrastructure at the same time, the simultaneous transmissions may cause channel congestion. While the issue of signal interference can be solved by the techniques of Visible Light Communication (VLC), vehicle clustering can be employed to improve the transmission performance of vehicles. VLC is an emerging technology with the advantage of immunity to electromagnetic interference. The technique of vehicle clustering categorizes vehicles into different sets, where each set has a leader for intra-cluster messaging. In this work, we present a clustering algorithm for VANET based on VLC. Our algorithm estimates the positions of vehicles based on their current movements. Then, it selects cluster heads based on the number of neighboring vehicles and generates clusters. We evaluate the performance of our scheme for both urban and highway scenarios. The simulation results show that the proposed algorithm can minimize the number of clusters and improve the transmission data rate for vehicles.
{"title":"Efficient Clustering of Visible Light Communications in VANET","authors":"Yu-Yen Chen, Pi-Chung Wang","doi":"10.3390/inventions8040083","DOIUrl":"https://doi.org/10.3390/inventions8040083","url":null,"abstract":"The deployment of vehicular ad hoc network (VANET) is crucial to the development of autonomous vehicles. Radio frequency (RF) technology has been employed to transmit messages between vehicles and infrastructure in VANET. However, the limited RF bands may cause interference when vehicles transmit messages in a high-density environment. Moreover, when numerous vehicles transmit messages to the infrastructure at the same time, the simultaneous transmissions may cause channel congestion. While the issue of signal interference can be solved by the techniques of Visible Light Communication (VLC), vehicle clustering can be employed to improve the transmission performance of vehicles. VLC is an emerging technology with the advantage of immunity to electromagnetic interference. The technique of vehicle clustering categorizes vehicles into different sets, where each set has a leader for intra-cluster messaging. In this work, we present a clustering algorithm for VANET based on VLC. Our algorithm estimates the positions of vehicles based on their current movements. Then, it selects cluster heads based on the number of neighboring vehicles and generates clusters. We evaluate the performance of our scheme for both urban and highway scenarios. The simulation results show that the proposed algorithm can minimize the number of clusters and improve the transmission data rate for vehicles.","PeriodicalId":14564,"journal":{"name":"Inventions","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46346231","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 : 2023-06-29DOI: 10.3390/inventions8040084
Ahmed Aghmadi, Hossam Hussein, Ketulkumar Hitesh Polara, Osama Mohammed
Networked microgrids (NMGs) are developing as a viable approach for integrating an expanding number of distributed energy resources (DERs) while improving energy system performance. NMGs, as compared to typical power systems, are constructed of many linked microgrids that can function independently or as part of a more extensive network. This allows NMGs to be more flexible, dependable, and efficient. The present study comprehensively investigates architecture, communication, and cybersecurity issues in NMGs. This comprehensive study examines various aspects related to networked microgrids (NMGs). It explores the architecture of NMGs, including control techniques, protection, standards, and the challenges associated with their adoption. Additionally, it investigates communication in NMGs, focusing on the technologies, protocols, and the impact of communication on the functioning of these systems. Furthermore, this study addresses cybersecurity challenges specific to NMGs, such as diverse cyberattack types, detection and mitigation strategies, and the importance of awareness training. The findings of this study offer valuable insights for NMG researchers and practitioners, emphasizing critical aspects that must be considered to ensure the safe and efficient operation of these systems.
{"title":"A Comprehensive Review of Architecture, Communication, and Cybersecurity in Networked Microgrid Systems","authors":"Ahmed Aghmadi, Hossam Hussein, Ketulkumar Hitesh Polara, Osama Mohammed","doi":"10.3390/inventions8040084","DOIUrl":"https://doi.org/10.3390/inventions8040084","url":null,"abstract":"Networked microgrids (NMGs) are developing as a viable approach for integrating an expanding number of distributed energy resources (DERs) while improving energy system performance. NMGs, as compared to typical power systems, are constructed of many linked microgrids that can function independently or as part of a more extensive network. This allows NMGs to be more flexible, dependable, and efficient. The present study comprehensively investigates architecture, communication, and cybersecurity issues in NMGs. This comprehensive study examines various aspects related to networked microgrids (NMGs). It explores the architecture of NMGs, including control techniques, protection, standards, and the challenges associated with their adoption. Additionally, it investigates communication in NMGs, focusing on the technologies, protocols, and the impact of communication on the functioning of these systems. Furthermore, this study addresses cybersecurity challenges specific to NMGs, such as diverse cyberattack types, detection and mitigation strategies, and the importance of awareness training. The findings of this study offer valuable insights for NMG researchers and practitioners, emphasizing critical aspects that must be considered to ensure the safe and efficient operation of these systems.","PeriodicalId":14564,"journal":{"name":"Inventions","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41693337","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 : 2023-06-28DOI: 10.3390/inventions8040082
Alexander Titov, Matteo Russo, M. Ceccarelli
The idea of an extension of life for CubeSats is proposed to reduce space debris in a low-earth orbit. In this work, a gripper is designed for geometry-based grasping in berthing tasks. The grasping operation is outlined for square- and rectangle-shaped CubeSats. Equilibrium conditions are formulated to design the fingertips’ shape and parameters for grasping CubeSat bodies. A design scheme is proposed to provide the required accuracy. A design concept is developed into a lab prototype by using low-cost 3D printing manufacturing, and a mock-up grasping task that is representative of the berthing operation is evaluated with the lab prototype. Center-mass hanging setup for the prototype and grasped body is used to evaluate the impact of grasping, partially replicating the conditions in space by reducing the effect of gravity on the system.
{"title":"Design and Operation of a Gripper for a Berthing Task","authors":"Alexander Titov, Matteo Russo, M. Ceccarelli","doi":"10.3390/inventions8040082","DOIUrl":"https://doi.org/10.3390/inventions8040082","url":null,"abstract":"The idea of an extension of life for CubeSats is proposed to reduce space debris in a low-earth orbit. In this work, a gripper is designed for geometry-based grasping in berthing tasks. The grasping operation is outlined for square- and rectangle-shaped CubeSats. Equilibrium conditions are formulated to design the fingertips’ shape and parameters for grasping CubeSat bodies. A design scheme is proposed to provide the required accuracy. A design concept is developed into a lab prototype by using low-cost 3D printing manufacturing, and a mock-up grasping task that is representative of the berthing operation is evaluated with the lab prototype. Center-mass hanging setup for the prototype and grasped body is used to evaluate the impact of grasping, partially replicating the conditions in space by reducing the effect of gravity on the system.","PeriodicalId":14564,"journal":{"name":"Inventions","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48851509","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 : 2023-06-24DOI: 10.3390/inventions8040080
Konstantinos Tsimnadis, Grigorios L. Kyriakopoulos, S. Leontopoulos
Since 2021, the prefectural authorities of the Attica Region in Greece have been operating a rewarding recycling program for the collection of clean recyclable waste in collaboration with the “Specialist Integrated Association of the Prefecture of Attica” (EDSNA, in Greek) and private contractors, called “THE GREEN CITY”. This program mobilizes almost 30 mobile green points (MGPs) daily, which are self-propelled trucks that collect clean recyclable materials from citizens and businesses across the Attica Region. After one year of operation, this program has shown promising results, having more than 100,000 registered citizens and having already collected over 500 tons of clean recyclable municipal solid wastes in more than 60 municipalities of Attica. However, these promising results are accompanied by some significant financial and environmental costs. This study presents two different practical improvement scenarios for THE GREEN CITY recycling program’s current situation that ensure (a) the shortening of the annual kilometers and time on the remote routes of all programs, (b) the annual fuel-cost decrease for the MGPs and (c) the annual reduction of their CO2 emissions into the atmosphere. Afterwards, we compare these two scenarios and conclude that the “first improvement scenario with main depot decentralization” is more realistic, feasible and has a bigger total sum of positive impacts than the second one. Therefore, this study strongly suggests the implementation of the “first improvement scenario with main depot decentralization” and opens the road to future improvement scenarios for various waste-management systems or recycling programs.
{"title":"Practical Improvement Scenarios for an Innovative Waste-Collection Recycling Program Operating with Mobile Green Points (MGPs)","authors":"Konstantinos Tsimnadis, Grigorios L. Kyriakopoulos, S. Leontopoulos","doi":"10.3390/inventions8040080","DOIUrl":"https://doi.org/10.3390/inventions8040080","url":null,"abstract":"Since 2021, the prefectural authorities of the Attica Region in Greece have been operating a rewarding recycling program for the collection of clean recyclable waste in collaboration with the “Specialist Integrated Association of the Prefecture of Attica” (EDSNA, in Greek) and private contractors, called “THE GREEN CITY”. This program mobilizes almost 30 mobile green points (MGPs) daily, which are self-propelled trucks that collect clean recyclable materials from citizens and businesses across the Attica Region. After one year of operation, this program has shown promising results, having more than 100,000 registered citizens and having already collected over 500 tons of clean recyclable municipal solid wastes in more than 60 municipalities of Attica. However, these promising results are accompanied by some significant financial and environmental costs. This study presents two different practical improvement scenarios for THE GREEN CITY recycling program’s current situation that ensure (a) the shortening of the annual kilometers and time on the remote routes of all programs, (b) the annual fuel-cost decrease for the MGPs and (c) the annual reduction of their CO2 emissions into the atmosphere. Afterwards, we compare these two scenarios and conclude that the “first improvement scenario with main depot decentralization” is more realistic, feasible and has a bigger total sum of positive impacts than the second one. Therefore, this study strongly suggests the implementation of the “first improvement scenario with main depot decentralization” and opens the road to future improvement scenarios for various waste-management systems or recycling programs.","PeriodicalId":14564,"journal":{"name":"Inventions","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48670363","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 : 2023-06-24DOI: 10.3390/inventions8040081
R. Elfahem, B. Abbès, B. Bouchet, S. Murer, F. Bogard, Tala Moussa, F. Beaumont, G. Polidori
(1) Background: This article presents a study that aims to provide a precise understanding of the temperature distribution within a whole-body cryostimulation (WBC) chamber, whether it is empty or occupied by one or several individuals; (2) Methods: The study employs a mixed numerical and experimental approach, utilizing simplified computational fluid dynamics (CFD) simulations and experimental analysis; (3) Results: The results reveal a non-negligible temperature difference between the setpoint and actual temperature in the middle of the cryochamber. Furthermore, it is shown that the presence of individuals inside the chamber results in both an average temperature rise and a more heterogeneous thermal behavior associated with the number of individuals present. As the number of occupants in the cryochamber increases, the magnitude of the thermal gradient (up to 10 °C) and temperature heterogeneity (up to 13%) also increase; (4) Conclusions: The results suggest that when the cryotherapy chamber is occupied by three people, it becomes necessary to extend the duration of cold exposure to obtain a dose/effect ratio and analgesic threshold equivalent to those obtained when only one person is present. The findings of this study emphasize the need for further research to establish temperature guidelines and standardize measurement methods for effective WBC treatment.
{"title":"Whole-Body Cryostimulation: New Insights in Thermo-Aeraulic Fields inside Chambers","authors":"R. Elfahem, B. Abbès, B. Bouchet, S. Murer, F. Bogard, Tala Moussa, F. Beaumont, G. Polidori","doi":"10.3390/inventions8040081","DOIUrl":"https://doi.org/10.3390/inventions8040081","url":null,"abstract":"(1) Background: This article presents a study that aims to provide a precise understanding of the temperature distribution within a whole-body cryostimulation (WBC) chamber, whether it is empty or occupied by one or several individuals; (2) Methods: The study employs a mixed numerical and experimental approach, utilizing simplified computational fluid dynamics (CFD) simulations and experimental analysis; (3) Results: The results reveal a non-negligible temperature difference between the setpoint and actual temperature in the middle of the cryochamber. Furthermore, it is shown that the presence of individuals inside the chamber results in both an average temperature rise and a more heterogeneous thermal behavior associated with the number of individuals present. As the number of occupants in the cryochamber increases, the magnitude of the thermal gradient (up to 10 °C) and temperature heterogeneity (up to 13%) also increase; (4) Conclusions: The results suggest that when the cryotherapy chamber is occupied by three people, it becomes necessary to extend the duration of cold exposure to obtain a dose/effect ratio and analgesic threshold equivalent to those obtained when only one person is present. The findings of this study emphasize the need for further research to establish temperature guidelines and standardize measurement methods for effective WBC treatment.","PeriodicalId":14564,"journal":{"name":"Inventions","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48849138","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 : 2023-06-05DOI: 10.3390/inventions8030079
Anita So, J. Reeves, Joshua M. Pearce
To improve accessibility, this article describes a static, four-legged walker that can be constructed from materials and fasteners commonly available from hardware stores coupled by open-source 3D-printed joints. The designs are described in detail, shared under an open-source license, and fabricated with a low-cost open-source desktop 3D printer and hand tools. The resulting device is loaded to failure to determine the maximum load that the design can safely support in both vertical and horizontal failure modes. The experimental results showed that the average vertical failure load capacity was 3680 ± 694.3 N, equivalent to 375.3 ± 70.8 kg of applied weight with the fractured location at the wood dowel handlebars. The average horizontal load capacity was 315.6 ± 49.4 N, equivalent to 32.2 ± 5.1 kg. The maximum weight capacity of a user of 187.1 ± 29.3 kg was obtained, which indicates that the open-source walker design can withstand the weight requirements of all genders with a 95% confidence interval that includes a safety factor of 1.8 when considering the lowest deviation weight capacity. The design has a cost at the bottom of the range of commercial walkers and reduces the mass compared to a commercial walker by 0.5 kg (19% reduction). It can be concluded that this open-source walker design can aid accessibility in low-resource settings.
{"title":"Open-Source Designs for Distributed Manufacturing of Low-Cost Customized Walkers","authors":"Anita So, J. Reeves, Joshua M. Pearce","doi":"10.3390/inventions8030079","DOIUrl":"https://doi.org/10.3390/inventions8030079","url":null,"abstract":"To improve accessibility, this article describes a static, four-legged walker that can be constructed from materials and fasteners commonly available from hardware stores coupled by open-source 3D-printed joints. The designs are described in detail, shared under an open-source license, and fabricated with a low-cost open-source desktop 3D printer and hand tools. The resulting device is loaded to failure to determine the maximum load that the design can safely support in both vertical and horizontal failure modes. The experimental results showed that the average vertical failure load capacity was 3680 ± 694.3 N, equivalent to 375.3 ± 70.8 kg of applied weight with the fractured location at the wood dowel handlebars. The average horizontal load capacity was 315.6 ± 49.4 N, equivalent to 32.2 ± 5.1 kg. The maximum weight capacity of a user of 187.1 ± 29.3 kg was obtained, which indicates that the open-source walker design can withstand the weight requirements of all genders with a 95% confidence interval that includes a safety factor of 1.8 when considering the lowest deviation weight capacity. The design has a cost at the bottom of the range of commercial walkers and reduces the mass compared to a commercial walker by 0.5 kg (19% reduction). It can be concluded that this open-source walker design can aid accessibility in low-resource settings.","PeriodicalId":14564,"journal":{"name":"Inventions","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46656139","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 : 2023-06-02DOI: 10.3390/inventions8030078
M. Chung, Chia-Chun Hsu, Siao-Rong Huang, Pin-Rui Huang
This paper presents a small-size broadband slot monopole chip antenna for millimeter wave application. Using a 0.18 μm CMOS process, through metal_1, the artificial magnetic conductor (AMC) of the metal layer increased the impedance bandwidth of the chip antenna. The additional inverted C branch was used to achieve a better reflection coefficient. By adding an AMC and inverted C branch, the operating frequency of the chip antenna went to 33.8–110 GHz below the reflection coefficient of −10 dB, and its fractional bandwidth was 103.4%. The maximum gain was −6.3 dBi at 72 GHz. The overall chip size was 1.2 × 1.2 (mm2). Through measurement and verification, the proposed antenna reflection coefficient was close to the simulation trend and had better resonance. The frequency range of the chip antenna proposed in this paper covered the 5G NR FR2 band (24.2 GHz–52.6 GHz) and W-band (75 GHz–110 GHz). The proposed chip antenna can be applied to the Internet of Things, Industry 4.0, biomedical electronics, near field sensing and other related fields.
{"title":"A 0.18 μm CMOS Millimeter Wave Antenna-on-Chip with Artificial Magnetic Conductor Design","authors":"M. Chung, Chia-Chun Hsu, Siao-Rong Huang, Pin-Rui Huang","doi":"10.3390/inventions8030078","DOIUrl":"https://doi.org/10.3390/inventions8030078","url":null,"abstract":"This paper presents a small-size broadband slot monopole chip antenna for millimeter wave application. Using a 0.18 μm CMOS process, through metal_1, the artificial magnetic conductor (AMC) of the metal layer increased the impedance bandwidth of the chip antenna. The additional inverted C branch was used to achieve a better reflection coefficient. By adding an AMC and inverted C branch, the operating frequency of the chip antenna went to 33.8–110 GHz below the reflection coefficient of −10 dB, and its fractional bandwidth was 103.4%. The maximum gain was −6.3 dBi at 72 GHz. The overall chip size was 1.2 × 1.2 (mm2). Through measurement and verification, the proposed antenna reflection coefficient was close to the simulation trend and had better resonance. The frequency range of the chip antenna proposed in this paper covered the 5G NR FR2 band (24.2 GHz–52.6 GHz) and W-band (75 GHz–110 GHz). The proposed chip antenna can be applied to the Internet of Things, Industry 4.0, biomedical electronics, near field sensing and other related fields.","PeriodicalId":14564,"journal":{"name":"Inventions","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2023-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42294822","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 : 2023-05-31DOI: 10.3390/inventions8030077
M. Korobkov, F. Vasilyev, O. Khomutskaya
Currently, there is a need to increase the density of interconnections on printed circuit boards (PCBs). Does this mean that the only option for quality PCB manufacturing is to proportionally increase precision of equipment, or is there another way? One of the main constraints on increasing the density of PCB interconnections is posed by the transition holes. As the number of conductive layers increases, the number of vias increases and they cover a significant space on the PCB. On the other hand, reducing the size of the vias is limited by the capability of spatial alignment of the PCB stack during manufacturing. There are standards that set limits for the design of contact pads on a PCB (IPC-A-600G, IPC-6012B). However, depending on the precision of production, the contact pads may be of poor quality. This raises the issue of determining the reliability of a contact pad with defined parameters at the design stage, taking into account manufacturing capabilities. This research proposes an analytical method for evaluation of reliability of a via or plated through-hole based on calculation of its probability of production in accordance with the current standards. On the basis of the method, a model was developed both for the case of a contact pad without any conductors connected to it (nonfunctional contact pad) and for the real case with a connected conductor. The model estimates the probability of making an acceptable via for a given reliability class depending on parameters such as the conductor width (minimum permissible and usable), drilled hole diameter, and pad diameter, as well as the accuracy of the drilling operation. The analysis of the modeling results showed that for the real case, a reduction in the reliability class would insignificantly affect the probability of making an acceptable via due to the tight limitation on the connection place of the conductor and the contact pad. In conclusion, we propose an algorithm for determining the optimal parameters of teardrops to minimize the negative impact of the conductor on the reliability of the vias.
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