Information Needs and Self-Care Practices of Diabetic Patients in Mbala, Northern Province, Zambia

Introduction: Diabetes mellitus (DM) is a chronic disease that occurs either when the pancreas does not produce enough insulin or when the body cannot effectively use the insulin it produces. It is “a group of metabolic diseases characterized by hyperglycemia resulting from defects in insulin secretion, insulin action or both” manifested by carbohydrates, fat and protein metabolism abnormality. If untreated high blood sugar can damage the nerves, eyes, kidneys, and other organs. The purpose of this study was to assess the information needs and self-care practice of Diabetic Patients in Mbala, Northern Province Zambia. Methods: This was an analytical cross-sectional study where 105 respondents aged 18 years and above participated in the study. Participants were randomly selected. A structured interview schedule and a check list were used to collect data. Statistics Package for Social Sciences computer software package version 23.0 was used to analyze data. Chi square and fisher’s exact tests were used to test the significance of the association between Knowledge of Diabetes Mellitus, attitude towards self-care practices, self-care practices among Diabetic patients and the need for information among Diabetic patients. A 95% confidence interval and P value of 0.05 were used to ascertain the degree of significance. Multi-variate binary logistic regression model to determine predictors of self-care practices and need for information was also used. Result: On analyzing the dependent variables, more than half (61.9%), had high need for information and three quarters (85.7%) of respondents had poor self-care practices. Slightly more than half (58.1%) had high knowledge levels majority (78.1%), had a negative attitude. Significant associations were found P Conclusion: Negative attitudes and lack of information among Diabetic patients were the main reasons associated with poor self-care practices. Particular attention should therefore be given to ensuring that Diabetic patients are given adequate information on Diabetes self-care in order to improve the quality of life.

Information needs of older people with heart failure： listening to their own voice

According to a large-scale census in 2000, there were approximately 4,000,000 patients with heart failure （HF） aged between 35 and 74 years in China. Patient education shows its importance and essentiality in controlling the disease by improving the self-care abilities of patients,t21 However, a shortened period of hospitalization compromises the effectiveness and efficacy of the education. It is therefore suggested that the information needs of patients with HF should be simultaneously addressed to make education more appropriate and tailored.

A survey of the information needs of visually impaired library users

Purpose:The research aims to investigate the information needs of visually impaired library users in China in order to increase our understanding of these users and help the Chinese public libraries improve their services for them.Design/methodology/approach:A questionnaire survey was used to study the library users’ information needs.Eleven large public libraries in different areas of China,which were pioneers in implementing services for visually impaired people,were chosen to conduct the survey.Data analysis was based on 97 valid questionnaires retrieved.Findings:Radio and television were still the preferred sources of information for visually impaired users.In information seeking,they had a strong preference for obtaining information in the most convenient way,and accessing a vast amount of information,which was updated quickly.They paid more attention to the information closely related to their work and life.Their purposes of seeking information were mainly for learning,relaxation and intercommunication.Visually impaired users felt some barriers in their access to library services such as a lack of time or a sighted companion who can come along for the trip to the library.Moreover,it was difficult for them to use the Internet to search for information,because many websites do not support the auxiliary software designed especially for visually impaired users or the websites offer only a paid subscriber service.Research limitations:A majority of the respondents were young and middle-aged people and engaged in work.The sample size needs to be enlarged,and different groups of users such as old people and students should be included to yield more useful results.Practical implications:The survey results provide insights into the information needs of the Chinese visually impaired library users.Meanwhile,the research can serve as a reference source for the future studies of the service for visually impaired library users.Originality/value:So far,few studies were conducted to investigate the information needs of visually impaired library users in China.

Inflammatory bowel disease patient profiles are related to specific information needs: A nationwide survey

BACKGROUND Inflammatory bowel diseases(IBD) is a heterogenous, lifelong disease, with an unpredictable and potentially progressive course, that may impose negative psychosocial impact on patients.While informed patients with chronic illness have improved adherence and outcomes, previous research showed that the majority of IBD patients receive insufficient information regarding their disease.The large heterogeneity of IBD and the wide range of information topics makes a one-size fits all knowledge resource overwhelming and cumbersome.We hypothesized that different patient profiles may have different and specific information needs, the identification of which will allow building personalized computer-based information resources in the future.AIM To evaluate the scope of disease-related knowledge among IBD patients and determine whether different patient profiles drive unique information needs.METHODS We conducted a nationwide survey addressing hospital-based IBD clinics.A Total of 571 patients completed a 28-item questionnaire, rating the amount of information received at time of diagnosis and the importance of information, as perceived by participants, for a newly diagnosed patient, and for the participants themselves, at current time.We performed an exploratory factor analysis of the crude responses aiming to create a number of representative knowledge domains(factors), and analyzed the responses of a set of 15 real-life patient profiles generated by the study team.RESULTS Participants gave low ratings for the amount of information received at disease onset(averaging 0.9/5) and high ratings for importance, both for the newly diagnosed patients(mean 4.2/5) and for the participants themselves at current time(mean 3.5/5).Factor analysis grouped responses into six informationdomains.The responses of selected profiles, compared with the rest of the participants, yielded significant associations(defined as a difference in rating of >0.5 points with a P < 0.05).Patients with active disease showed a higher interest in work-disability, stress-coping, and therapy-complications.Patients newly diagnosed at age > 50, and patients with long-standing disease(> 10 years)showed less interest in work-disability.Patients in remission with mesalamine or no therapy showed less interest in all domains except for nutrition and long-term complications.CONCLUSION We demonstrate unmet patient information needs.Analysis of various patient profiles revealed associations with specific information topics, paving the way for building patient-tailored information resources.

Information Needs of Breast Cancer Patients at Cancer Diseases Hospital, Lusaka, Zambia

Background: Breast cancer is the second most common cancer worldwide and the second most common among Zambian women. Breast cancer diagnosis being a stressful experience, causes psychological and emotional disruption that can be abated by meeting information needs of the affected patients. In light of the escalating cases of Breast cancer among the Zambian women, the study examined a special aspect of cancer management which is usually neglected in most cases. Aim: The main objective of the study was to assess information needs of breast cancer patients at the Cancer Diseases Hospital in Lusaka, Zambia using a modified structured interview schedule adopted from the Toronto Information Needs Questionnaire-Breast Cancer (TINQ-BC). Methods: A descriptive cross-sectional design was used to elicit the information needs of breast cancer patients. One hundred and ten (97% response rate) participants were selected using simple random sampling method and data was collected using a modified structured interview schedule adopted from the Toronto Information Needs Questionnaire-Breast Cancer (TINQ-BC). Stata 10.0 (StataCorp, 2008) was employed for all quantitative data analysis and graphical presentation of data. Results: The overall score for information needs was obtained by adding the scores across all the five information needs categories which were further divided into three categories namely: low important scores, of less than 50%, moderately important scores of 50% - 70% and highly important scores ranged above 70% of the 200 total scores. Out of the 110 participants recruited, 88 (80%) indicated that the information across the five categories was moderately important. Logistic regression of information needs and posited determinants revealed that anxiety levels;education level;presence of co-morbidity;and being on treatment were significant determinants of patients’ informational needs (Effect’s p ≤ 0.05). Conclusion: The findings of this study support the idea that breast cancer patients are seeking more information on their illness, hence information provision is one of the most important factors for providing high quality cancer care across the whole cancer continuum. Therefore, appreciating the information needs of breast cancer patients is substantial in improving care.

A study of changing information needs of contemporary public library users in China

Public libraries should be vigilant and responsive to the ever changing information needs of their clientele functioning in a society undergoing through rapid change due to technological innovations. China is currently experiencing a social and technological transformation of great magnitude in terms of metamorphosing itself from a traditional society to one that is driven by information technologies. Our research study, taking this proposition into account, did a questionnaire survey on 954 library information users at five major public libraries. This research study has discovered that the information needs of public library users today reflect some of the peculiar characteristics of their society in changing times which is driven largely by the rapid development and application of new information technologies. It shows that there is a newly added demand emphasis on certain categories of library resources and services by the Chinese reading public. Our research findings have identified such needs basically in the following five functional areas of public libraries, namely, 1) Increased demands for economic resources, 2) rising expectations for more effective and efficient library services, 3) a convenient location and an amicable environment congenial to learning, 4) a suitable place for engaging in intellectual dialogues and in socialization, and 5) a few other technological amenities and information technology-based digital resources and facilities in addition to a rich repository of library materials in print format. Finally, our paper concludes its discussion with a few observation remarks about the changing trend of public libraries' visions, missions and operations vis-à-vis a contextual background of the ever heightened public expectations for getting quality information services in a timely manner in order for them to function effectively in an information-oriented society such as that of ours today.

Silent information regulator sirtuin 1 ameliorates acute liver failure via the p53/glutathione peroxidase 4/gasdermin D axis

BACKGROUND Acute liver failure(ALF)has a high mortality with widespread hepatocyte death involving ferroptosis and pyroptosis.The silent information regulator sirtuin 1(SIRT1)-mediated deacetylation affects multiple biological processes,including cellular senescence,apoptosis,sugar and lipid metabolism,oxidative stress,and inflammation.AIM To investigate the association between ferroptosis and pyroptosis and the upstream regulatory mechanisms.METHODS This study included 30 patients with ALF and 30 healthy individuals who underwent serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST)testing.C57BL/6 mice were also intraperitoneally pretreated with SIRT1,p53,or glutathione peroxidase 4(GPX4)inducers and inhibitors and injected with lipopolysaccharide(LPS)/D-galactosamine(D-GalN)to induce ALF.Gasdermin D(GSDMD)^(-/-)mice were used as an experimental group.Histological changes in liver tissue were monitored by hematoxylin and eosin staining.ALT,AST,glutathione,reactive oxygen species,and iron levels were measured using commercial kits.Ferroptosis-and pyroptosis-related protein and mRNA expression was detected by western blot and quantitative real-time polymerase chain reaction.SIRT1,p53,and GSDMD were assessed by immunofluorescence analysis.RESULTS Serum AST and ALT levels were elevated in patients with ALF.SIRT1,solute carrier family 7a member 11(SLC7A11),and GPX4 protein expression was decreased and acetylated p5,p53,GSDMD,and acyl-CoA synthetase long-chain family member 4(ACSL4)protein levels were elevated in human ALF liver tissue.In the p53 and ferroptosis inhibitor-treated and GSDMD^(-/-)groups,serum interleukin(IL)-1β,tumour necrosis factor alpha,IL-6,IL-2 and C-C motif ligand 2 levels were decreased and hepatic impairment was mitigated.In mice with GSDMD knockout,p53 was reduced,GPX4 was increased,and ferroptotic events(depletion of SLC7A11,elevation of ACSL4,and iron accumulation)were detected.In vitro,knockdown of p53 and overexpression of GPX4 reduced AST and ALT levels,the cytostatic rate,and GSDMD expression,restoring SLC7A11 depletion.Moreover,SIRT1 agonist and overexpression of SIRT1 alleviated acute liver injury and decreased iron deposition compared with results in the model group,accompanied by reduced p53,GSDMD,and ACSL4,and increased SLC7A11 and GPX4.Inactivation of SIRT1 exacerbated ferroptotic and pyroptotic cell death and aggravated liver injury in LPS/D-GalNinduced in vitro and in vivo models.CONCLUSION SIRT1 activation attenuates LPS/D-GalN-induced ferroptosis and pyroptosis by inhibiting the p53/GPX4/GSDMD signaling pathway in ALF.

Influence of initial check, information exchange, final accuracy check, reaction information nursing on the psychology of elderly with lung cancer

BACKGROUND As one of the fatal diseases with high incidence,lung cancer has seriously endangered public health and safety.Elderly patients usually have poor self-care and are more likely to show a series of psychological problems.AIM To investigate the effectiveness of the initial check,information exchange,final accuracy check,reaction(IIFAR)information care model on the mental health status of elderly patients with lung cancer.METHODS This study is a single-centre study.We randomly recruited 60 elderly patients with lung cancer who attended our hospital from January 2021 to January 2022.These elderly patients with lung cancer were randomly divided into two groups,with the control group taking the conventional propaganda and education and the observation group taking the IIFAR information care model based on the conventional care protocol.The differences in psychological distress,anxiety and depression,life quality,fatigue,and the locus of control in psychology were compared between these two groups,and the causes of psychological distress were analyzed.RESULTS After the intervention,Distress Thermometer,Hospital Anxiety and Depression Scale(HADS)for anxiety and the HADS for depression,Revised Piper’s Fatigue Scale,and Chance Health Locus of Control scores were lower in the observation group compared to the pre-intervention period in the same group and were significantly lower in the observation group compared to those of the control group(P<0.05).After the intervention,Quality of Life Questionnaire Core 30(QLQ-C30),Internal Health Locus of Control,and Powerful Others Health Locus of Control scores were significantly higher in the observation and the control groups compared to the pre-intervention period in their same group,and QLQ-C30 scores were significantly higher in the observation group compared to those of the control group(P<0.05).CONCLUSION The IIFAR information care model can help elderly patients with lung cancer by reducing their anxiety and depression,psychological distress,and fatigue,improving their tendencies on the locus of control in psychology,and enhancing their life qualities.

Attribute Reduction of Hybrid Decision Information Systems Based on Fuzzy Conditional Information Entropy

The presence of numerous uncertainties in hybrid decision information systems(HDISs)renders attribute reduction a formidable task.Currently available attribute reduction algorithms,including those based on Pawlak attribute importance,Skowron discernibility matrix,and information entropy,struggle to effectively manages multiple uncertainties simultaneously in HDISs like the precise measurement of disparities between nominal attribute values,and attributes with fuzzy boundaries and abnormal values.In order to address the aforementioned issues,this paper delves into the study of attribute reduction withinHDISs.First of all,a novel metric based on the decision attribute is introduced to solve the problem of accurately measuring the differences between nominal attribute values.The newly introduced distance metric has been christened the supervised distance that can effectively quantify the differences between the nominal attribute values.Then,based on the newly developed metric,a novel fuzzy relationship is defined from the perspective of“feedback on parity of attribute values to attribute sets”.This new fuzzy relationship serves as a valuable tool in addressing the challenges posed by abnormal attribute values.Furthermore,leveraging the newly introduced fuzzy relationship,the fuzzy conditional information entropy is defined as a solution to the challenges posed by fuzzy attributes.It effectively quantifies the uncertainty associated with fuzzy attribute values,thereby providing a robust framework for handling fuzzy information in hybrid information systems.Finally,an algorithm for attribute reduction utilizing the fuzzy conditional information entropy is presented.The experimental results on 12 datasets show that the average reduction rate of our algorithm reaches 84.04%,and the classification accuracy is improved by 3.91%compared to the original dataset,and by an average of 11.25%compared to the other 9 state-of-the-art reduction algorithms.The comprehensive analysis of these research results clearly indicates that our algorithm is highly effective in managing the intricate uncertainties inherent in hybrid data.

Robust Information Hiding Based on Neural Style Transfer with Artificial Intelligence

This paper proposes an artificial intelligence-based robust information hiding algorithm to address the issue of confidential information being susceptible to noise attacks during transmission.The algorithm we designed aims to mitigate the impact of various noise attacks on the integrity of secret information during transmission.The method we propose involves encoding secret images into stylized encrypted images and applies adversarial transfer to both the style and content features of the original and embedded data.This process effectively enhances the concealment and imperceptibility of confidential information,thereby improving the security of such information during transmission and reducing security risks.Furthermore,we have designed a specialized attack layer to simulate real-world attacks and common noise scenarios encountered in practical environments.Through adversarial training,the algorithm is strengthened to enhance its resilience against attacks and overall robustness,ensuring better protection against potential threats.Experimental results demonstrate that our proposed algorithm successfully enhances the concealment and unknowability of secret information while maintaining embedding capacity.Additionally,it ensures the quality and fidelity of the stego image.The method we propose not only improves the security and robustness of information hiding technology but also holds practical application value in protecting sensitive data and ensuring the invisibility of confidential information.

Needs and Opportunities for Information in Patients with Metastatic Breast Cancer Attending a Tertiary Hospital in Tanzania—A Qualitative Study

Background: The majority of breast cancer patients in Tanzania present with advanced disease, and a significant proportion has metastatic breast cancer (MBC) on presentation or develops it during the course of their follow-up. With few treatment options to choose from, such patients often benefit from empathic support and access to information to help them make treatment decisions based on their individual circumstances and needs. Patients with MBC have been shown to present with unique physical, social and psychological needs that require additional time, counselling and availability of health care providers in addition to the routine options available to other patients. In resource-limited settings, the needs of such patients are often unknown and unaddressed, which adds to the anxiety associated with the diagnosis and its treatment. Materials and methods: This descriptive qualitative study was conducted using 3 focus group discussions with a total of 17 participants with metastatic breast cancer (MBC) attending Ocean Road Cancer Institute in Dar es Salaam, Tanzania. Participants were purposively selected for the study from outpatient clinics and inpatient wards. A semi-structured FGD guide was used to moderate discussions and analysis was done using a thematic approach. Results: The median age of participants was 51 (range 33 - 81 years) with an average of 4 months (range 1 - 12 months) from diagnosis of BC to the interview. 4 (24%) were diagnosed with MBC on first presentation (denovo). Participants spoke about the importance of accurate BC-related information in allowing timely referral and treatment both in the community and within the health system. They recognized the role of mass and social media in increasing awareness about BC and identified myths surrounding cancer treatment especially mastectomy. Correct and timely information at points of care, through media platforms and via ambassadors/patient support groups was perceived as a means to avoiding delays and securing early and effective treatment. Conclusion: Patients with MBC in Tanzania have many unmet informational needs in relation to their disease. Accurate BC-related information is important in allowing early detection and diagnosis. At the community level, provision of information through established media platforms and the use of patient advocates may help to enable early referral and treatment of patients.

A framework of force of information influence and application for C4KISR system

The subversive nature of information war lies not only in the information itself, but also in the circulation and application of information. It has always been a challenge to quantitatively analyze the function and effect of information flow through command, control, communications, computer, kill, intelligence,surveillance, reconnaissance (C4KISR) system. In this work, we propose a framework of force of information influence and the methods for calculating the force of information influence between C4KISR nodes of sensing, intelligence processing,decision making and fire attack. Specifically, the basic concept of force of information influence between nodes in C4KISR system is formally proposed and its mathematical definition is provided. Then, based on the information entropy theory, the model of force of information influence between C4KISR system nodes is constructed. Finally, the simulation experiments have been performed under an air defense and attack scenario. The experimental results show that, with the proposed force of information influence framework, we can effectively evaluate the contribution of information circulation through different C4KISR system nodes to the corresponding tasks. Our framework of force of information influence can also serve as an effective tool for the design and dynamic reconfiguration of C4KISR system architecture.

Tuning the diffusion constant to optimize the readout of positional information of spatial concentration patterns

Positional information encoded in spatial concentration patterns is crucial for the development of multicellular organisms.However,it is still unclear how such information is affected by the physically dissipative diffusion process.Here we study one-dimensional patterning systems with analytical derivation and numerical simulations.We find that the diffusion constant of the patterning molecules exhibits a nonmonotonic effect on the readout of the positional information from the concentration patterns.Specifically,there exists an optimal diffusion constant that maximizes the positional information.Moreover,we find that the energy dissipation due to the physical diffusion imposes a fundamental upper limit on the positional information.

Information Conductivity:Universal Performance Measure for Semantic Communications

As a novel paradigm,semantic communication provides an effective solution for breaking through the future development dilemma of classical communication systems.However,it remains an unsolved problem of how to measure the information transmission capability for a given semantic communication method and subsequently compare it with the classical communication method.In this paper,we first present a review of the semantic communication system,including its system model and the two typical coding and transmission methods for its implementations.To address the unsolved issue of the information transmission capability measure for semantic communication methods,we propose a new universal performance measure called Information Conductivity.We provide the definition and the physical significance to state its effectiveness in representing the information transmission capabilities of the semantic communication systems and present elaborations including its measure methods,degrees of freedom,and progressive analysis.Experimental results in image transmission scenarios validate its practical applicability.

Dynamic Update Scheme of Spectrum Information Based on Spectrum Opportunity Incentive in the Database-Assisted Dynamic Spectrum Management

To solve the problem of delayed update of spectrum information(SI) in the database assisted dynamic spectrum management(DB-DSM), this paper studies a novel dynamic update scheme of SI in DB-DSM. Firstly, a dynamic update mechanism of SI based on spectrum opportunity incentive is established, in which spectrum users are encouraged to actively assist the database to update SI in real time. Secondly, the information update contribution(IUC) of spectrum opportunity is defined to describe the cost of accessing spectrum opportunity for heterogeneous spectrum users, and the profit of SI update obtained by the database from spectrum allocation. The process that the database determines the IUC of spectrum opportunity and spectrum user selects spectrum opportunity is mapped to a Hotelling model. Thirdly, the process of determining the IUC of spectrum opportunities is further modelled as a Stackelberg game by establishing multiple virtual spectrum resource providers(VSRPs) in the database. It is proved that there is a Nash Equilibrium in the game of determining the IUC of spectrum opportunities by VSRPs. Finally, an algorithm of determining the IUC based on a genetic algorithm is designed to achieve the optimal IUC. The-oretical analysis and simulation results show that the proposed method can quickly find the optimal solution of the IUC, and ensure that the spectrum resource provider can obtain the optimal profit of SI update.

Does social information affect the settlement decisions of resident birds in their second breeding attempt?A case study of the Japanese Tit(Parus minor)

Individuals may gather information about environmental conditions when deciding where to breed in order to maximize their lifetime fitness.They can obtain social information by observing conspecifics and heterospecifics with similar ecological needs.Many studies have shown that birds can rely on social information to select their nest sites.The location of active nests and the reproductive success of conspecifics and heterospecifics can provide accurate predictions about the quality of the breeding habitat.Some short-lived species can facultatively reproduce two and/or more times within a breeding season.However,few studies have focused on how multiplebrooding individuals select nest sites for their second breeding attempts.In this study,we use long-term data to test whether the Japanese Tit(Parus minor)can use social information from conspecifics and/or heterospecifics(the Eurasian Nuthatch Sitta europaea,the Daurian Redstart Phoenicurus auroreus and the Yellow-rumped Flycatcher Ficedula zanthopygia)to select a nest site for the second breeding attempt.Our results showed that the nest boxes occupied by tits on their second breeding attempt tended to be surrounded by more breeding conspecific nests,successful first nests of conspecifics,and fewer failed first nests of conspecifics than the nest boxes that remained unoccupied(the control group).However,the numbers of breeding heterospecific nests,successful heterospecific nests,and failed heterospecific nests did not differ between the nest boxes occupied by tits on their second breeding attempt and the unoccupied nest boxes.Furthermore,the tits with local successful breeding experience tended to choose areas with more successful first nests of conspecifics than those without successful breeding experience.Thus,we suggest that conspecifics'but not heterospecifics'social information within the same breeding season is the major factor influencing the nest site selection of Japanese Tits during second breeding attempts.

Witnessing quantum phase transition in a non-Hermitian trapped ion system via quantum Fisher information

Quantum Fisher information is used to witness the quantum phase transition in a non-Hermitian trapped ion system with balanced gain and loss,from the viewpoint of quantum parameter estimation.We formulate a general non-unitary dynamic of any two-level non-Hermitian system in the form of state vector.The sudden change in the dynamics of quantum Fisher information occurs at an exceptional point characterizing quantum criticality.The dynamical behaviors of quantum Fisher information are classified into two different ways which depends on whether the system is located in symmetry unbroken or broken phase regimes.In the phase regime where parity and time reversal symmetry are unbroken,the oscillatory evolution of quantum Fisher information is presented,achieving better quantum measurement precision.In the broken phase regime,quantum Fisher information undergoes the monotonically decreasing behavior.The maximum value of quantum estimation precision is obtained at the exceptional point.It is found that the two distinct kinds of behaviors can be verified by quantum entropy and coherence.Utilizing quantum Fisher information to witness phase transition in the non-Hermitian system is emphasized.The results may have potential applications to non-Hermitian quantum information technology.

Mutual Information Maximization via Joint Power Allocation in Integrated Sensing and Communications System

In this paper, we focus on the power allocation of Integrated Sensing and Communication(ISAC) with orthogonal frequency division multiplexing(OFDM) waveform. In order to improve the spectrum utilization efficiency in ISAC, we propose a design scheme based on spectrum sharing, that is,to maximize the mutual information(MI) of radar sensing while ensuring certain communication rate and transmission power constraints. In the proposed scheme, three cases are considered for the scattering off the target due to the communication signals,as negligible signal, beneficial signal, and interference signal to radar sensing, respectively, thus requiring three power allocation schemes. However,the corresponding power allocation schemes are nonconvex and their closed-form solutions are unavailable as a consequence. Motivated by this, alternating optimization(AO), sequence convex programming(SCP) and Lagrange multiplier are individually combined for three suboptimal solutions corresponding with three power allocation schemes. By combining the three algorithms, we transform the non-convex problem which is difficult to deal with into a convex problem which is easy to solve and obtain the suboptimal solution of the corresponding optimization problem. Numerical results show that, compared with the allocation results of the existing algorithms, the proposed joint design algorithm significantly improves the radar performance.

A guidance and control design with reduced information for a dual-spin stabilized projectile

In this paper,an integrated guidance and control method based on an adaptive path-following controller is proposed to control a spin-stabilized projectile with only translational motion information under the constraint of an actuator,uncertainties in aerodynamic parameters and measurements,and control system complexity.Owing to the fairly high rotation speed,the dynamic model of this missile is strongly nonlinear,uncertain and coupled in pitch,yaw and roll channels.A theoretical equivalent resultant force and uncertainty compensation method are comprehensively used to realize decoupling of pitch and yaw.In response to the strong nonlinear and time-varying characteristics of the dynamic system,the quasi-linear model whose parameters are obtained by interpolation of points selected as the segmentation points in the trajectory envelope,is used for calculation in each step.To cope with the system uncertainty caused by model approximation,parameter uncertainty and ballistic interference,an extended state estimator is used to compensate the output feedback according to the test ballistic angle.In order to improve the tracking efficiency and ensure the tracking error convergence with only translational motion information,the virtual guide point,whose derivative is deduced according to the Lyapunov principle,is calculated in real time according to the projection relationship between the real-time position and the reference trajectory,and a virtual line-of-sight angle and the backstepping method are used for the design of the guidance and control system.In order to avoid the influence of control input saturation on the guidance and control performance due to the actuator limitation and improve the robustness of the system,an anti-saturation compensator is designed according to the two-step method.The feasibility and effectiveness of the path-following controller is verified through closed-loop flight simulations with measurement,control,and condition uncertainties.The results indicate that the designed controller can converge to the reference path and evidently decrease the distance between the impact point and target under different uncertainties.

Improving the Effectiveness of Image Classification Structural Methods by Compressing the Description According to the Information Content Criterion

The research aims to improve the performance of image recognition methods based on a description in the form of a set of keypoint descriptors.The main focus is on increasing the speed of establishing the relevance of object and etalon descriptions while maintaining the required level of classification efficiency.The class to be recognized is represented by an infinite set of images obtained from the etalon by applying arbitrary geometric transformations.It is proposed to reduce the descriptions for the etalon database by selecting the most significant descriptor components according to the information content criterion.The informativeness of an etalon descriptor is estimated by the difference of the closest distances to its own and other descriptions.The developed method determines the relevance of the full description of the recognized object with the reduced description of the etalons.Several practical models of the classifier with different options for establishing the correspondence between object descriptors and etalons are considered.The results of the experimental modeling of the proposed methods for a database including images of museum jewelry are presented.The test sample is formed as a set of images from the etalon database and out of the database with the application of geometric transformations of scale and rotation in the field of view.The practical problems of determining the threshold for the number of votes,based on which a classification decision is made,have been researched.Modeling has revealed the practical possibility of tenfold reducing descriptions with full preservation of classification accuracy.Reducing the descriptions by twenty times in the experiment leads to slightly decreased accuracy.The speed of the analysis increases in proportion to the degree of reduction.The use of reduction by the informativeness criterion confirmed the possibility of obtaining the most significant subset of features for classification,which guarantees a decent level of accuracy.