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Updating the PSVD of this matrix is much more efficient than recalculating it after each change.
This shows that the differential properties in the matrix case are much more complicated than in the scalar situation.
Open accessJournal ArticleDOI
13 Citations
We prove that a C^1 real-valued function always induces a C^1 matrix function and give an explicit formula for the derivative.
Finally, we prove that all compact Cauchy matrices could be modified into an involution compact Cauchy matrix, and show how to maximize the occurrences of entry “1” in a compact Cauchy matrix.
Open accessJournal ArticleDOI
Dongpo Xu, Danilo P. Mandic 
73 Citations
Illustrative examples show how the proposed quaternion matrix derivatives can be used as an important tool for solving optimization problems in signal processing applications.
Further study of this analysis suggests that the taking of arbitrary variations in the 1‐matrix at a certain point in their study may result in an invalid Euler equation for the 1‐matrix energy functional, although this does not alter the main results of that work.

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Is MD2 a monomer or dimer?
5 answers
MD-2, a protein essential for Toll-like receptor 4 (TLR4) activation by lipopolysaccharide (LPS), exists as a mixture of disulfide-linked oligomers, indicating its dimeric nature. The Rho GTPase binding domain of Plexin-B1 (RBD) also exhibits dimerization, affecting its dynamic structure and conformational entropy. In contrast, the monomer-dimer (MD) problem on a random planar honeycomb lattice model involves calculating the MD partition function for bipartite graphs, corresponding to the permanent of a matrix, indicating a dimeric state. Additionally, the study on Mdm2 and MdmX proteins highlights the significance of dimerization for their E3 ubiquitin ligase activity, with mutations affecting dimer formation and subsequent protein degradation, emphasizing the role of dimerization in their functions. Collectively, these findings suggest that MD-2 can exist as a dimeric protein.
What are the most common physical characteristics of suspects in criminal investigations?
10 answers
In criminal investigations, the identification and analysis of suspects' physical characteristics are crucial for narrowing down suspects and solving cases. Recent research has highlighted various physical characteristics that are commonly analyzed. Gestures, including hand movements and body language, are significant indicators of a suspect's behavior and can be automatically identified using deep learning techniques with high accuracy levels. Beyond gestures, the anatomical features on the dorsal surface of the hand, such as the occurrence rate of specific hand features, have been studied to assist in forensic investigations, showing significant variation between males and females. DNA analysis has become routine in forensic science, providing not only the genetic profile but also the potential to estimate the biological age of the individual from biological stains, adding another layer of physical characteristic useful in investigations. The ICM_Apriori algorithm has improved the efficiency of mining criminal data, including suspects' characteristics, by significantly reducing the time required for analysis. Interviews and the study of white-collar crime also reveal that socioeconomic status and occupational roles can be considered indirect physical or demographic characteristics relevant in certain criminal investigations. Dermatological conditions affecting fingerprints can complicate the identification process, indicating the importance of skin conditions as a physical characteristic in criminalistics. Facial attributes, defined and extracted using automated algorithms, serve as critical identifiers in the absence of traditional eyewitness sketches, highlighting the role of describable facial features in suspect identification. The personality and lifestyle choices, including substance abuse, can indirectly influence physical characteristics or the perception thereof in criminal profiles. Forensic dentistry emphasizes the uniqueness of dental structures as a vital physical characteristic in identifying suspects or victims in crimes. Lastly, the use of subjective feature-based mug shot retrieval systems demonstrates the importance of witnesses' perceptions of suspects' physical features, further underscoring the variety of characteristics used in criminal investigations.
What are the most common characteristics of suspects in criminal investigations?
10 answers
The most common characteristics of suspects in criminal investigations can be discerned through various analytical lenses, including behavioral evidence analysis, psychological profiling, interrogation outcomes, and the application of technology and algorithms in criminal investigations. Behavioral evidence analysis suggests that investigatively relevant characteristics of suspects include criminal skill, knowledge of the victim, the crime scene, and methods and materials, although profilers often err in deducing characteristics like age, sex, and intelligence. The application of technology, specifically deep learning techniques, has shown efficacy in identifying suspects based on unique behavioral cues such as body language and hand gestures, with a high accuracy level in distinguishing between positive and negative gestures. Psychological profiling, particularly through polygraph surveys, highlights the importance of emotional and behavioral traits such as reactive aggression, emotional lability, and a tendency towards emotional instability among suspects. This is complemented by the use of the Behavior Analysis Interview (BAI), which effectively differentiates between deceptive and truthful suspects by assessing verbal and nonverbal cues, with a notable accuracy in identifying deceptive behaviors. Criminal investigations also benefit from the analysis of suspects' characteristics through algorithms like the ICM_Apriori, which improves the efficiency of mining criminal rules and clues from crime data. Moreover, the study of criminal careers reveals patterns of generalist and specialist behaviors among suspects, influenced by factors such as age and gender, with women showing a propensity towards certain types of crimes like fraud. Interrogation outcomes further elucidate suspects' characteristics, indicating that previous contact with the police and personal traits significantly influence the truthfulness and content of suspects' confessions. Additionally, psychological assessments of detainees have identified mental health, memory and suggestibility, previous criminality, and literacy and IQ as significant factors. In summary, the most common characteristics of suspects in criminal investigations encompass a broad spectrum of behavioral, emotional, psychological, and demographic traits, as well as criminal skills and knowledge, all of which are crucial for effective profiling, interrogation, and investigation processes.
What are the stages of new technology adoption?
5 answers
The stages of new technology adoption encompass various dimensions and factors. Initially, the diffusion process involves decomposing adoption traces into sequential stages based on user involvement and adoption speed, ensuring a structured transition. Factors influencing successful adoption include readiness measures like feasibility, quality, and staff receptiveness, which can be positively impacted through targeted simulation-based interventions. Additionally, shifts in concerns (self, task, impact) and usability (trust, usefulness, ease of use) are experienced during the adoption process by healthcare professionals. Risks associated with adopting new IT technologies include innovation risks, security concerns, and productivity impacts, necessitating a comprehensive risk assessment and management strategy. Understanding how new technologies interact with existing routines can reveal change triggers and stabilization mechanisms, influencing the early adoption dynamics in construction contexts.
What is ASCII file?
5 answers
An ASCII file is a type of file format that utilizes ASCII (American Standard Code for Information Interchange) characters for encoding data. ASCII art, a form of ASCII file, represents images using character shapes and is commonly used on internet bulletin boards. ASCII-based encryption/decryption applications can be applied to various file types, such as images, data files, audio files, and more, by translating ASCII values of characters into binary mode. Additionally, an ASCII file format has been proposed for exchanging large systems of nonlinear ordinary differential matrix equations, supporting dense and sparse matrices with the inclusion of nonlinear functions and couplings. Furthermore, ASCII text-cover centric data hiding schemes are being researched to enhance information security through steganography, addressing issues like copyright infringement and e-theft.
How does CDOM absorption compare with other methods for predicting water pollution, in terms of accuracy and efficiency?
10 answers
The comparison of CDOM absorption methods with other techniques for predicting water pollution reveals a nuanced landscape of accuracy and efficiency across various studies. CDOM, or chromophoric dissolved organic matter, plays a crucial role in the biogeochemical and carbon cycles of aquatic environments, with its absorption being a significant part of light absorptions in these systems. The use of machine learning algorithms, such as Gaussian process regression (GPR), has shown high stability and estimation accuracy for CDOM absorption coefficients, outperforming traditional empirical models in inland waters. This suggests a potential for high accuracy in CDOM-based monitoring approaches. In contrast, other predictive models for water quality, such as those targeting chemical oxygen demand (COD) using spectral technology and particle swarm algorithms, have also demonstrated good prediction effects. These methods, while distinct from CDOM absorption techniques, offer a stable, fast, and real-time measurement capability that is crucial for effective water pollution control and treatment. UV-visible imaging spectroscopy, an emerging technology, has been anticipated to improve the remote sensing of coastal waters by facilitating the detection of CDOM in optically complex waters. This method, especially when incorporating UV reflectance, significantly improves the retrieval of CDOM absorption coefficients, indicating its efficiency and accuracy in monitoring coastal water quality. Furthermore, the exploration of CDOM sources and dynamics through machine learning models like XGBoost has provided insights into the spectral slopes of CDOM, offering a more detailed understanding of its characteristics in marine environments. The identification of fluorescent components of CDOM in urban waters and their correlation with pollution levels further underscores the utility of CDOM analysis in real-time water quality monitoring. Comparatively, studies on the spectral characteristics of CDOM in highly polluted waters have highlighted the importance of understanding CDOM optical properties and their relationship with water quality. Seasonal characteristics of fluorescent CDOM components in polluted watershed tributaries have also been examined, demonstrating the influence of environmental factors on CDOM dynamics. In summary, while CDOM absorption methods offer promising accuracy and efficiency in monitoring water pollution, especially when enhanced by machine learning algorithms and UV-visible imaging spectroscopy, they are part of a broader toolkit that includes other predictive models for water quality assessment. Each method has its strengths and applications, suggesting that a comprehensive approach, possibly integrating multiple techniques, could provide the most accurate and efficient water pollution prediction.
What are the limitations and challenges associated with using CDOM absorption for predicting water pollution?
10 answers
The use of Chromophoric Dissolved Organic Matter (CDOM) absorption as a predictor for water pollution faces several limitations and challenges, as highlighted by recent research. One primary challenge is the difficulty in accurately measuring in situ CDOM absorption coefficients due to the necessity of prefiltration of water samples, which can be cumbersome and time-consuming. Additionally, the complex optical conditions in inland waters, such as those found in eutrophic lakes, can significantly challenge the remote sensing estimates of CDOM, thereby affecting the accuracy of water pollution predictions. Moreover, the spectral characteristics of CDOM can vary significantly with the water quality and spectral parameters, especially in highly polluted waters, making it difficult to develop universally applicable bio-optical models. The variability in CDOM properties across different regions and trophic states further complicates the use of CDOM absorption for predicting water pollution, as the relationship between CDOM and dissolved organic carbon (DOC) can vary, affecting the applicability of remote sensing monitoring. The seasonal characteristics of CDOM also introduce variability, with different fluorescent CDOM components showing seasonal variations that can influence the quantity and quality of CDOM in water samples. This seasonal variability, along with the spatial discrepancy in CDOM optical properties, necessitates the development of region-specific algorithms and models. Furthermore, the emerging technology of UV-visible imaging spectroscopy, while promising for improving the remote sensing of CDOM in optically complex waters, has yet to be fully evaluated for its potential advantages in monitoring CDOM-related water quality. The fluorescence characteristics of CDOM, which can be indicative of pollution levels, also vary spatially and with pollution levels, requiring sophisticated analysis methods like EEM-PARAFAC to interpret. Lastly, the influence of anthropogenic disturbances on CDOM characteristics, as observed in the Liaohe River Delta, underscores the need for tools that can trace the sources and characteristics of CDOM to effectively monitor riverine water quality. These challenges highlight the need for continued research and development of more robust, efficient, and region-specific methods for using CDOM absorption as a predictor for water pollution.
How generate DEM from SAR satellite images?
5 answers
Generating Digital Elevation Models (DEMs) from Synthetic Aperture Radar (SAR) satellite images involves various methods. One approach involves using interferometric SAR (InSAR) technology, which utilizes phase information from SAR images to derive elevation data. Another method is based on radargrammetry, where DEMs are created by analyzing the offset between multi-aspect SAR images on the ground plane. Circular SAR imaging can also be employed, where a two-step process involving target separation and height estimation is utilized to generate DEMs with high accuracy. Additionally, a multistatic SAR system with dual-baseline interferometry has been shown to provide DEMs with exceptional resolution and vertical accuracy, surpassing previous standards. These diverse techniques showcase the advancements in utilizing SAR satellite data for precise DEM generation.
How is Hitting Set Enumeration used in data profiling/data dependencies?
5 answers
Hitting Set Enumeration is crucial in data profiling and data dependency tasks. It aids in discovering fundamental concepts like Functional Dependencies (FDs), Unique Column Combinations (UCCs), and Minimal Hitting Sets of hypergraphs. These algorithms efficiently identify hidden patterns in data, such as minimal and valid FDs on relational instances, entities in databases, and unique column combinations. By modeling metadata discovery as a hitting set enumeration problem, these techniques leverage efficient search strategies and theoretical insights to improve the speed and resource efficiency of discovering crucial data structures. The application of hitting set enumeration in data profiling allows for faster and more accurate identification of essential data relationships and patterns, enhancing data management activities in various domains.
How to do co-word analysis?
4 answers
Co-word analysis involves constructing a network of words based on their co-occurrence in scholarly publications to reveal the intellectual structure of a knowledge domain. To conduct co-word analysis effectively, one can utilize methods like knowledge mapping techniques, subject knowledge networks, and semantic relevance calculations based on meta-paths. It is essential to perform centrality analysis, cluster analysis, and filtering procedures to identify major research themes, knowledge structures, and to make the resulting network interpretable. By analyzing co-occurrence patterns of keywords, researchers can uncover research hotspots, frontiers, and trends within a specific discipline, enabling a deeper understanding of the conceptual structure and scientific evolution of the field being studied.
Whats the purpose of a stakeholder matrix
5 answers
The purpose of a stakeholder matrix is to aid in effective stakeholder management by identifying and analyzing the various stakeholders involved in a project or organization. Stakeholder matrices help in determining the level of interest and influence of each stakeholder group, guiding appropriate communication strategies and relationship-building activities. These matrices also assist in understanding stakeholders' inclinations and influences on decisions, such as land use planning in buffer zones. By utilizing stakeholder matrices, organizations can navigate complex stakeholder landscapes, enhance communication, and make informed decisions that align with stakeholders' expectations and needs. Additionally, stakeholder matrices contribute to minimizing resistance from stakeholders by considering their interests and power dynamics, ultimately facilitating smoother project implementation.