Compression before Fusion: Broadcast Semantic Communication System for Heterogeneous Tasks

Semantic communication has emerged as new paradigm shifts in 6G from the conventional syntax-oriented communications. Recently, the wireless broadcast technology has been introduced to support semantic communication system toward higher communication efficiency. Nevertheless, existing broadcast semantic communication systems target on general representation within one stage and fail to balance the inference accuracy among users. In this paper, the broadcast encoding process is decomposed into compression and fusion to improves communication efficiency with adaptation to tasks and channels.Particularly, we propose multiple task-channel-aware sub-encoders (TCE) and a channel-aware feature fusion sub-encoder (CFE) towards compression and fusion, respectively. In TCEs, multiple local-channel-aware attention blocks are employed to extract and compress task-relevant information for each user. In GFE, we introduce a global-channel-aware fine-tuning block to merge these compressed task-relevant signals into a compact broadcast signal. Notably, we retrieve the bottleneck in DeepBroadcast and leverage information bottleneck theory to further optimize the parameter tuning of TCEs and CFE.We substantiate our approach through experiments on a range of heterogeneous tasks across various channels with additive white Gaussian noise (AWGN) channel, Rayleigh fading channel, and Rician fading channel. Simulation results evidence that the proposed DeepBroadcast outperforms the state-of-the-art methods

Comparative Analysis of ELV Recycling Policies in the European Union, Japan and China: Analiza porównawcza regulacji dotyczących recyklingu ELV w Unii Europejskiej, Japonii i Chinach

This research aims at revealing the current status of the End-of-Life Vehicle (ELV) recycling systems in the European Union (EU), Japan and China which are known to have big vehicle manufacturers. The purpose of this research is to clarify their characteristics and issues, such as existing ELV recycling policy, limitations of Extended Producer Responsibility (EPR) and environmental problems caused by secondhand car export. Japanese ELV recycling system will be analyzed as a specific example. Automakers’ effort to improve ELV recycling rate and the potential influence on recycling policy from large secondhand car export and Next-Generation Vehicle’s (NGV) popularization in Japan will be discussed and generalized. In addition, interview investigation for vehicle makers and government agencies has been conducted to have a comparative analysis of stakeholders’ (mainly automakers) attitude towards current ELV recycling law and future plans which can support Next-Generation Vehicle recycling well, as well as cross-border environmental/international resources recycling problems caused by secondhand car export

A Bibliometric Research on Next-Generation Vehicles Using CiteSpace

Next-generation vehicles (NGVs), which mainly refers to hybrid vehicles (HVs), plug-in hybrid vehicles (PHVs), electric vehicles (EVs), fuel-cell vehicles (FCVs), and clean diesel vehicles (CDVs), are becoming more and more popular as the potential answer to decreasing fossil fuel consumption and CO2 emission from traffic sectors. Although the research on NGVs started in the 1990s, a systematic observation or summarization of the research on NGVs has not been performed yet. Thus, the current status, characteristics, latest trends, and issues of the research on NGVs have not been clarified yet. This research analyzed the research on NGVs recorded in the Web of Science published between 1990 to 2020 using CiteSpace, from a macro perspective. The results show that HVs and EVs are the crucial research objects in comparison with FCVs and CDVs. The research on NGVs was mainly performed by countries that own large vehicle makers or markets. However, it is noticeable that many developing countries have also started to study NGVs, which proves that NGVs have become popular globally. On the other hand, the research topics and categories of NGV study have always had a strong bias in favor of their function and technology development. Since NGVs have been sold for years in many countries already, there will be a considerable number of waste NGVs generated in the future, and so, future research should focus on recycling policies and/or recycling technology for NGVs to guarantee their sustainable development

A Bibliometric Research on Next-Generation Vehicles Using CiteSpace

Next-generation vehicles (NGVs), which mainly refers to hybrid vehicles (HVs), plug-in hybrid vehicles (PHVs), electric vehicles (EVs), fuel-cell vehicles (FCVs), and clean diesel vehicles (CDVs), are becoming more and more popular as the potential answer to decreasing fossil fuel consumption and CO2 emission from traffic sectors. Although the research on NGVs started in the 1990s, a systematic observation or summarization of the research on NGVs has not been performed yet. Thus, the current status, characteristics, latest trends, and issues of the research on NGVs have not been clarified yet. This research analyzed the research on NGVs recorded in the Web of Science published between 1990 to 2020 using CiteSpace, from a macro perspective. The results show that HVs and EVs are the crucial research objects in comparison with FCVs and CDVs. The research on NGVs was mainly performed by countries that own large vehicle makers or markets. However, it is noticeable that many developing countries have also started to study NGVs, which proves that NGVs have become popular globally. On the other hand, the research topics and categories of NGV study have always had a strong bias in favor of their function and technology development. Since NGVs have been sold for years in many countries already, there will be a considerable number of waste NGVs generated in the future, and so, future research should focus on recycling policies and/or recycling technology for NGVs to guarantee their sustainable development

Feasibility study on the evaluation of the effect of narrow-band CE-Chirp ASSR in the hearing field after hearing aid in hearing-impaired children

Objective Study: Whether the narrow-band CE-Chirp ASSR test in the sound field is an objective evaluation method for the hearing aid compensation effect, and whether there is a difference in children with different hearing loss levels. Methods: 39 children (67 ears) wearing full digital hearing aids with good rehabilitation effect and ability to cooperate with behavioral audiometry were selected. The narrow-band CE-Chirp ASSR test group in the sound field was set as the experimental group, and the sound field behavioral audiometry after hearing aid was set as the control group. According to the degree of hearing loss, it was divided into moderate hearing loss group, severe hearing loss group and extremely severe hearing loss group. The difference between test results of experimental group and control group was compared. Results: There were no significant differences between the experimental group and the control group in the moderate hearing loss group and the extremely severe hearing loss group at 0.5, 1, 2, and 4kHz (P > 0.05). The results of the experimental group and the control group in the severe hearing loss group, There was no significant difference at 0.5, 1, 2kHz (P > 0.05), there was a significant difference at 4kHz (P < 0.05), and the mean difference was - 6.4dB HL. When the degree of hearing loss was not grouped, there was no significant difference between the experimental group and the control group at 0.5, 1, 2kHz (P > 0.05), 4kHz was significantly different (P < 0.05), and the mean difference was -3.2dB HL. Conclusion: It is clinically feasible to evaluate the hearing aid compensation effect of the narrow-band CE-Chirp ASSR in the hearing-impaired children. The grouping according to the degree of hearing loss can be more accurate in evaluating the hearing aid compensation effect. The narrow-band CE-Chirp in the sound field of children with moderate and very severe hearing loss ASSR results can be directly used to assess the hearing aid compensation effect, while children with severe hearing loss need to apply correction values at 4kHz

Life-Cycle Assessment on Nickel-Metal Hydride Battery in Hybrid Vehicles: Comparison between Regenerated and New Battery: Ocena cyklu życia akumulatora niklowo-wodorkowego w pojazdach hybrydowych: porównanie akumulatora regenerowanego i nowego

To reduce air pollution and avoid petroleum exhaustion problem, many advanced countries, especially Japan installed Hybrid Vehicles (HV). As the use of HV popularizes around the world, there will be a huge amount of End-of-Life HV in the near future, and the proper treatment of these End-of-Life HVs, especially the waste NiMH (Nickel-Metal Hydride) batteries, will become a serious problem. Currently, the recycling of NiMH battery is gaining substantial attention. However, instead of recycling waste NiMH batteries directly, regenerating and reusing a used NiMH battery for a secondhand HV will largely reduce waste battery generation and demand for new NiMH battery. However, the environmental impact of regenerating and reusing a waste NiMH battery was not clear and has not been compared with the situation when using a brand-new NiMH battery. The purpose of this research is to compare the environmental performance (CO2 emission) of regenerated NiMH battery and brand-new NiMH battery in an HV from their production to usage stage and to discuss the validity of using a regenerated NiMH in Japan and in other countries using the Life-Cycle Assessment (LCA) approach. This research analyzed the composition of a NiMH battery and the CO2 emission during the manufacture, transportation, regeneration and usage process of a NiMH battery. The data used in this research was collected from reports and data published by the government of Japan, vehicle makers and previous studies. Original field survey and interview research on battery regeneration operators were also performed. The result showed that there is not a big difference in environmental effect. Moreover, by doing so, a huge amount of resource will be saved from battery manufacturing process while reducing waste generation. It is recommended that waste NiMH battery should be regenerated and reused in HV instead of being recycled directly in the future