China in the Arctic : A Perception of European Arctic States

The Arctic region is under great transformation due to climate change. The retreating sea and land ice has revealed opportunities for potential natural resources and new shipping routes, which have attracted both Arctic and non-Arctic states competing for them. They basically manage the Arctic affairs under the auspices of the Arctic Council. China, identifying itself as a “near-Arctic” state, has also joined the “Arctic rush”, hoping to be benefited from the Arctic resources. This thesis, through qualitative research method and the lens of realistic international relations theory, does a research on the participation of China in Arctic affairs and the opinions and attitudes of the European Arctic states towards it. The result is that the European Arctic states hold twofold attitudes and opinions towards China: they engage with it in an active yet cautious attitude; they regard it as an indispensable partner and a potential destabilizer in the region as well. This thesis also makes discussions on three questions regarding the geopolitical situations in the Arctic involving China and gives corresponding recommendations

Exploring Student Check-In Behavior for Improved Point-of-Interest Prediction

With the availability of vast amounts of user visitation history on location-based social networks (LBSN), the problem of Point-of-Interest (POI) prediction has been extensively studied. However, much of the research has been conducted solely on voluntary checkin datasets collected from social apps such as Foursquare or Yelp. While these data contain rich information about recreational activities (e.g., restaurants, nightlife, and entertainment), information about more prosaic aspects of people's lives is sparse. This not only limits our understanding of users' daily routines, but more importantly the modeling assumptions developed based on characteristics of recreation-based data may not be suitable for richer check-in data. In this work, we present an analysis of education "check-in" data using WiFi access logs collected at Purdue University. We propose a heterogeneous graph-based method to encode the correlations between users, POIs, and activities, and then jointly learn embeddings for the vertices. We evaluate our method compared to previous state-of-the-art POI prediction methods, and show that the assumptions made by previous methods significantly degrade performance on our data with dense(r) activity signals. We also show how our learned embeddings could be used to identify similar students (e.g., for friend suggestions).Comment: published in KDD'1

End-to-end Online Speaker Diarization with Target Speaker Tracking

This paper proposes an online target speaker voice activity detection system for speaker diarization tasks, which does not require a priori knowledge from the clustering-based diarization system to obtain the target speaker embeddings. By adapting the conventional target speaker voice activity detection for real-time operation, this framework can identify speaker activities using self-generated embeddings, resulting in consistent performance without permutation inconsistencies in the inference phase. During the inference process, we employ a front-end model to extract the frame-level speaker embeddings for each coming block of a signal. Next, we predict the detection state of each speaker based on these frame-level speaker embeddings and the previously estimated target speaker embedding. Then, the target speaker embeddings are updated by aggregating these frame-level speaker embeddings according to the predictions in the current block. Our model predicts the results for each block and updates the target speakers' embeddings until reaching the end of the signal. Experimental results show that the proposed method outperforms the offline clustering-based diarization system on the DIHARD III and AliMeeting datasets. The proposed method is further extended to multi-channel data, which achieves similar performance with the state-of-the-art offline diarization systems.Comment: Submitted to IEEE/ACM Transactions on Audio, Speech, and Language Processin

Exploring supervised and unsupervised methods to detect topics in biomedical text

BACKGROUND: Topic detection is a task that automatically identifies topics (e.g., "biochemistry" and "protein structure") in scientific articles based on information content. Topic detection will benefit many other natural language processing tasks including information retrieval, text summarization and question answering; and is a necessary step towards the building of an information system that provides an efficient way for biologists to seek information from an ocean of literature. RESULTS: We have explored the methods of Topic Spotting, a task of text categorization that applies the supervised machine-learning technique naïve Bayes to assign automatically a document into one or more predefined topics; and Topic Clustering, which apply unsupervised hierarchical clustering algorithms to aggregate documents into clusters such that each cluster represents a topic. We have applied our methods to detect topics of more than fifteen thousand of articles that represent over sixteen thousand entries in the Online Mendelian Inheritance in Man (OMIM) database. We have explored bag of words as the features. Additionally, we have explored semantic features; namely, the Medical Subject Headings (MeSH) that are assigned to the MEDLINE records, and the Unified Medical Language System (UMLS) semantic types that correspond to the MeSH terms, in addition to bag of words, to facilitate the tasks of topic detection. Our results indicate that incorporating the MeSH terms and the UMLS semantic types as additional features enhances the performance of topic detection and the naïve Bayes has the highest accuracy, 66.4%, for predicting the topic of an OMIM article as one of the total twenty-five topics. CONCLUSION: Our results indicate that the supervised topic spotting methods outperformed the unsupervised topic clustering; on the other hand, the unsupervised topic clustering methods have the advantages of being robust and applicable in real world settings

Cloud manufacturing architecture: a critical analysis of its development, characteristics and future agenda to support its adoption

Purpose: In the last decade, cloud manufacturing (CMfg) has attracted considerable attention from academia and industry worldwide. It is widely accepted that the design and analysis of cloud manufacturing architecture (CMfg-A) are the basis for developing and applying CMfg systems. However, in existing studies, analysis of the status, development process and internal characteristics of CMfg-A is lacking, hindering an understanding of the research hotspots and development trends of CMfg-A. Meanwhile, effective guidance is lacking on the construction of superior CMfg-As. The purpose of this paper is to review the relevant research on CMfg-A via identification of the main layers, elements, relationships, structure and functions of CMfg-A to provide valuable information to scholars and practitioners for further research on key CMfg-A technologies and the construction of CMfg systems with superior performance. Design/methodology/approach: This study systematically reviews the relevant research on CMfg-A across transformation process to internal characteristics by integrating quantitative and qualitative methods. First, the split and reorganization method is used to recognize the main layers of CMfg-A. Then, the transformation process of six main layers is analysed through retrospective analysis, and the similarities and differences in CMfg-A are obtained. Subsequently, based on systematic theory, the elements, relationships, structure and functions of CMfg-A are inductively studied. A 3D printing architecture design case is conducted to discuss the weakness of the previous architecture and demonstrate how to improve it. Finally, the primary current trends and future opportunities are presented. Findings: By analyzing the transformation process of CMfg-A, this study finds that CMfg-A resources are developing from tangible resources into intangible resources and intelligent resources. CMfg-A technology is developing from traditional cloud computing-based technology towards advanced manufacturing technology, and CMfg-A application scope is gradually expanding from traditional manufacturing industry to emerging manufacturing industry. In addition, by analyzing the elements, relationships, structure and functions of CMfg-A, this study finds that CMfg-A is undergoing a new generation of transformation, with trends of integrated development, intelligent development, innovative development and green development. Case study shows that the analysis of the development trend and internal characteristics of the architecture facilitates the design of a more effective architecture. Research limitations/implications: This paper predominantly focuses on journal articles and some key conference papers published in English and Chinese. The reason for considering Chinese articles is that CMfg was proposed by the Chinese and a lot of Chinese CMfg-A articles have been published in recent years. CMfg is suitable for the development of China’s manufacturing industry because of China’s intelligent manufacturing environment. It is believed that this research has reached a reliable comprehensiveness that can help scholars and practitioners establish new research directions and evaluate their work in CMfg-A. Originality/value: Prior studies ignore the identification and analysis of development process and internal characteristics for the current development of CMfg-A, including the main layers identification of different CMfg-As and the transformation process analysis of these main layers, and in-depth analysis of the inner essence of CMfg-A (such as its elements, relationships, structure and functions). This study addresses these limitations and provides a comprehensive literature review

The DKU-DUKEECE System for the Manipulation Region Location Task of ADD 2023

This paper introduces our system designed for Track 2, which focuses on locating manipulated regions, in the second Audio Deepfake Detection Challenge (ADD 2023). Our approach involves the utilization of multiple detection systems to identify splicing regions and determine their authenticity. Specifically, we train and integrate two frame-level systems: one for boundary detection and the other for deepfake detection. Additionally, we employ a third VAE model trained exclusively on genuine data to determine the authenticity of a given audio clip. Through the fusion of these three systems, our top-performing solution for the ADD challenge achieves an impressive 82.23% sentence accuracy and an F1 score of 60.66%. This results in a final ADD score of 0.6713, securing the first rank in Track 2 of ADD 2023.Comment: The DKU-DukeECE system description to Task 2 of Audio Deepfake Detection Challenge (ADD 2023

Fe plaque assisted aquatic U rhizofiltration by Phragmites australis Trin ex Steud. –: Performance and influence factors in natural-like wetland and mesocosm environments

The macrophytes have the ability accumulating multiple metals/metalloids species from the terrestrial and aquatic environments. The environmental-friendly phytoremediation technologies via these plant species have been applied for non-degradable pollutants removal. The macrophytes derived rhizofiltration is a major and efficient technology for metals/metalloids removal, especially in aquatic environments (e.g. wetland). Comparing with the common metals/metalloids often studied, aquatic U rhizofiltration via macrophytes has been just considered recently. In this study, the field investigation in a U tailing basin wetland showed that the rhizofiltration was crucial for aquatic U retention via Phragmites australis Trin ex Steud. (water to root bioconcentration factor (BCF): 670 to 1556). The aquatic U retention efficiency in aboveground biomass of P. australis was insufficient (BCF: 0.4 to 5.3), comparing with the rhizofiltration. However, the high productivity (1.2 to 1.9 kg•m-2 per growing season) of P. australis still resulted in a notable yearly U accumulation in the areal total aboveground biomass (0.04 to 0.35 mg•m-2 per growing season). It was potentially promoted by the enhanced aquatic U rhizofiltration. The U within aboveground biomass could be released to submerse soil with the degradable or recalcitrant fallen litters. It enhanced the organic carbon supply in rhizosphere together with the root litter, and potential water to root U translocation within mobilized organic compounds. Hence the rhizofiltration stood in the crucial position of the plant-litter-water-soil U recycling in aquatic environment. The results from field investigation and mesocosm experiment further suggested that the Fe plaque (IP) on root surface was crucial for aquatic U rhizofiltration. The IP contained most of root retained U in both environments (proportion of U within IP: 55.8 to 82.6% in field and 66.7 to 86.0% in mesocosm). However, the efficiency of IP assisted aquatic U rhizofiltration was affected by the redox state gradient (-179 to 220 mV) related redox processes. Field investigation suggested that high content of dissolved oxygen (up to 8.2 mg•l-1) was capable to rapidly oxidize soluble Fe(II) as sparingly soluble Fe(III) oxides precipitated in subhydric soil. It consequently limited the aquatic Fe availability for root uptake and precipitation as IP. However, the strong oxidation ability also relatively increased aquatic U(VI) availability incorporated with inorganics and degradable organic matters. It was adverse for controlling the aquatic U concentration (66.7 to 92.0 μg•l-1 in field). On the other hand, it also benefited the U uptake by inner root tissue and upward translocation to aboveground biomass of P. australis. The different inorganic N species also significantly influenced IP assisted aquatic U rhizofiltration. The aquatic NH4+ sustained the reduction and acidification (via nitirification) potential for Fe(III) and U(VI) bioreduction in rhizosphere (-87 to 21 mV in NH4+ cultured mesocosm pots). It improved the root uptake (mainly within IP) of Fe and U (2992.9 to 5010.7 mg•kg-1 Fe and 45.7 to 62.8 mg•kg-1 U in NH4+ cultured root). On the contrary, the NO3- depended strong oxidation ability (23 to 224 mV in NO3- cultured mesocosm pots) inhibited the IP formation and the related aquatic U rhizofiltration efficiency (1568.5 to 2569.5 mg•kg-1 Fe and 26.2 to 49.6 mg•kg-1 U in NO3- cultured root). The aquatic U availability in rhizosphere was also increased via NO3- depended oxidation processes (aquatic U concentration in mesocosm: 1.6 to 589.3 μg•L-1 (NO3-) vs. 1.4 to 58.2 μg•L-1 (NH4+)). The sufficient nitrogen supply is also a significant driving force for high biomass productivity of P. australis. The higher biomass of P. australis increased the U accumulation capacity for root and aboveground tissues. The nitrogen related high biomass accumulation of P. australis also potentially enhanced the share of organic bound U in subhydric soil via plant litters supply. The IP assisted aquatic U rhizofiltration was also affected by the co-existing metals/metalloids in rhizosphere. The field investigation indicated that high As availability (aquatic As/U ratio: 0.7 to 1.6) inhibited the U retention within IP through the competitive absorption, due to its high affinity to IP. The Ca improved the aquatic U(VI) availability by forming the soluble Ca-uranyl-carbonate compounds. The Ca also potentially competed with hydrated Fe(III) oxides within IP by incorporating with U and encourage the U retention within inner root tissue. The P was beneficial for U retention within IP possibly in form of U-Fe-phosphate complexes. However, it was still need to be proofed in further studies. Despite of the biogeochemical conditions in rhizosphere, the aboveground transpiration of P. australis also affected the IP formation and related aquatic U rhizofiltration. The higher transpiration rate (TR) of P. australis (3.3±1.2 mm•d-1 in field, 4.5±2.0 mm•d-1 (NH4+)/5.0±2.2 mm•d-1(NO3-) in mesocosm) increased the aquatic nutrient/non-essential elements availability for root uptake. For this reason, the aquatic U rhizofiltration of P. australis (21.8±3.1 mg•kg-1 in field, 62.1±1.0 mg•kg-1 (NH4+)/47.6±1.8 mg•kg-1 (NO3-) in mesocosm) was enhanced under higher TR. The higher TR also promoted the formation of IP and its U retention capacity. Furthermore, the U translocation from root to above ground biomass (mainly in leaves) of P. australis was also enhanced under higher TR. It was potentially benefited by the increased transpirational pull and root uptake of other active mediator (e.g. Ca). The effect of transpiration was also coupled with the different N species on IP assisted aquatic U rhizofiltration. The higher TR depended strong root uptake and assimilation of N increased the biomass accumulation of P. australis. Furthermore, the higher TR also potentially increased the share of root in biomass partition of P. australis. Consequently, the stronger transpiration resulted in the higher aquatic U accumulation in area related root biomass (up to 84.0±3.6 mg•m-2 (NH4+) and 86.4±5.8 mg•m-2 (NO3-) U per season in mesocosm). In conclusion, it was possible for eutrophic P. australis stands to retain the aquatic U via rhizofiltration. The IP on root surface was a crucial mediator contributing the aquatic U rhizofiltration, especially in iron rich milieu. The efficiency of IP assisted aquatic U rhizofiltration could be further improved under suitable environmental conditions. In this study, these conditions might include: i) reductive rhizosphere environment with active reducers (e.g. NH4+) encouraging Fe(II) generation for IP formation and U retention within it; ii) limited competitive elements (e.g. As and Ca) co-existed with Fe and U in rhizosphere; iii) sufficient nutrients (e.g. N) supply and related high biomass productivity of plant; iv) strong transpiration effect improved the nutrient assimilation of root and also the aquatic U/Fe availability for root uptake. By adjusting these conditions (also include other potential factors not discussed in this study), an effective rhizofiltration technology was supposed to be applied for aquatic U removal

Fe plaque assisted aquatic U rhizofiltration by Phragmites australis Trin ex Steud. –: Performance and influence factors in natural-like wetland and mesocosm environments

The macrophytes have the ability accumulating multiple metals/metalloids species from the terrestrial and aquatic environments. The environmental-friendly phytoremediation technologies via these plant species have been applied for non-degradable pollutants removal. The macrophytes derived rhizofiltration is a major and efficient technology for metals/metalloids removal, especially in aquatic environments (e.g. wetland). Comparing with the common metals/metalloids often studied, aquatic U rhizofiltration via macrophytes has been just considered recently. In this study, the field investigation in a U tailing basin wetland showed that the rhizofiltration was crucial for aquatic U retention via Phragmites australis Trin ex Steud. (water to root bioconcentration factor (BCF): 670 to 1556). The aquatic U retention efficiency in aboveground biomass of P. australis was insufficient (BCF: 0.4 to 5.3), comparing with the rhizofiltration. However, the high productivity (1.2 to 1.9 kg•m-2 per growing season) of P. australis still resulted in a notable yearly U accumulation in the areal total aboveground biomass (0.04 to 0.35 mg•m-2 per growing season). It was potentially promoted by the enhanced aquatic U rhizofiltration. The U within aboveground biomass could be released to submerse soil with the degradable or recalcitrant fallen litters. It enhanced the organic carbon supply in rhizosphere together with the root litter, and potential water to root U translocation within mobilized organic compounds. Hence the rhizofiltration stood in the crucial position of the plant-litter-water-soil U recycling in aquatic environment. The results from field investigation and mesocosm experiment further suggested that the Fe plaque (IP) on root surface was crucial for aquatic U rhizofiltration. The IP contained most of root retained U in both environments (proportion of U within IP: 55.8 to 82.6% in field and 66.7 to 86.0% in mesocosm). However, the efficiency of IP assisted aquatic U rhizofiltration was affected by the redox state gradient (-179 to 220 mV) related redox processes. Field investigation suggested that high content of dissolved oxygen (up to 8.2 mg•l-1) was capable to rapidly oxidize soluble Fe(II) as sparingly soluble Fe(III) oxides precipitated in subhydric soil. It consequently limited the aquatic Fe availability for root uptake and precipitation as IP. However, the strong oxidation ability also relatively increased aquatic U(VI) availability incorporated with inorganics and degradable organic matters. It was adverse for controlling the aquatic U concentration (66.7 to 92.0 μg•l-1 in field). On the other hand, it also benefited the U uptake by inner root tissue and upward translocation to aboveground biomass of P. australis. The different inorganic N species also significantly influenced IP assisted aquatic U rhizofiltration. The aquatic NH4+ sustained the reduction and acidification (via nitirification) potential for Fe(III) and U(VI) bioreduction in rhizosphere (-87 to 21 mV in NH4+ cultured mesocosm pots). It improved the root uptake (mainly within IP) of Fe and U (2992.9 to 5010.7 mg•kg-1 Fe and 45.7 to 62.8 mg•kg-1 U in NH4+ cultured root). On the contrary, the NO3- depended strong oxidation ability (23 to 224 mV in NO3- cultured mesocosm pots) inhibited the IP formation and the related aquatic U rhizofiltration efficiency (1568.5 to 2569.5 mg•kg-1 Fe and 26.2 to 49.6 mg•kg-1 U in NO3- cultured root). The aquatic U availability in rhizosphere was also increased via NO3- depended oxidation processes (aquatic U concentration in mesocosm: 1.6 to 589.3 μg•L-1 (NO3-) vs. 1.4 to 58.2 μg•L-1 (NH4+)). The sufficient nitrogen supply is also a significant driving force for high biomass productivity of P. australis. The higher biomass of P. australis increased the U accumulation capacity for root and aboveground tissues. The nitrogen related high biomass accumulation of P. australis also potentially enhanced the share of organic bound U in subhydric soil via plant litters supply. The IP assisted aquatic U rhizofiltration was also affected by the co-existing metals/metalloids in rhizosphere. The field investigation indicated that high As availability (aquatic As/U ratio: 0.7 to 1.6) inhibited the U retention within IP through the competitive absorption, due to its high affinity to IP. The Ca improved the aquatic U(VI) availability by forming the soluble Ca-uranyl-carbonate compounds. The Ca also potentially competed with hydrated Fe(III) oxides within IP by incorporating with U and encourage the U retention within inner root tissue. The P was beneficial for U retention within IP possibly in form of U-Fe-phosphate complexes. However, it was still need to be proofed in further studies. Despite of the biogeochemical conditions in rhizosphere, the aboveground transpiration of P. australis also affected the IP formation and related aquatic U rhizofiltration. The higher transpiration rate (TR) of P. australis (3.3±1.2 mm•d-1 in field, 4.5±2.0 mm•d-1 (NH4+)/5.0±2.2 mm•d-1(NO3-) in mesocosm) increased the aquatic nutrient/non-essential elements availability for root uptake. For this reason, the aquatic U rhizofiltration of P. australis (21.8±3.1 mg•kg-1 in field, 62.1±1.0 mg•kg-1 (NH4+)/47.6±1.8 mg•kg-1 (NO3-) in mesocosm) was enhanced under higher TR. The higher TR also promoted the formation of IP and its U retention capacity. Furthermore, the U translocation from root to above ground biomass (mainly in leaves) of P. australis was also enhanced under higher TR. It was potentially benefited by the increased transpirational pull and root uptake of other active mediator (e.g. Ca). The effect of transpiration was also coupled with the different N species on IP assisted aquatic U rhizofiltration. The higher TR depended strong root uptake and assimilation of N increased the biomass accumulation of P. australis. Furthermore, the higher TR also potentially increased the share of root in biomass partition of P. australis. Consequently, the stronger transpiration resulted in the higher aquatic U accumulation in area related root biomass (up to 84.0±3.6 mg•m-2 (NH4+) and 86.4±5.8 mg•m-2 (NO3-) U per season in mesocosm). In conclusion, it was possible for eutrophic P. australis stands to retain the aquatic U via rhizofiltration. The IP on root surface was a crucial mediator contributing the aquatic U rhizofiltration, especially in iron rich milieu. The efficiency of IP assisted aquatic U rhizofiltration could be further improved under suitable environmental conditions. In this study, these conditions might include: i) reductive rhizosphere environment with active reducers (e.g. NH4+) encouraging Fe(II) generation for IP formation and U retention within it; ii) limited competitive elements (e.g. As and Ca) co-existed with Fe and U in rhizosphere; iii) sufficient nutrients (e.g. N) supply and related high biomass productivity of plant; iv) strong transpiration effect improved the nutrient assimilation of root and also the aquatic U/Fe availability for root uptake. By adjusting these conditions (also include other potential factors not discussed in this study), an effective rhizofiltration technology was supposed to be applied for aquatic U removal