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基于Relief-F算法的心血管介入患者术后死亡风险预测
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作者 杨健斌 李咏 +3 位作者 夏淑东 齐鹏嘉 戴燕云 童基均 《浙江理工大学学报(自然科学版)》 2024年第3期378-388,共11页
针对心血管介入患者全周期病理数据普遍存在缺失、不连续、非结构化等问题,建立了心血管介入专病数据库,并采用基于Relief-F算法的预测方法,对心血管介入患者术后死亡风险进行预测。首先参照HL7、CDISC等国际心血管疾病统一标准对各数... 针对心血管介入患者全周期病理数据普遍存在缺失、不连续、非结构化等问题,建立了心血管介入专病数据库,并采用基于Relief-F算法的预测方法,对心血管介入患者术后死亡风险进行预测。首先参照HL7、CDISC等国际心血管疾病统一标准对各数据源进行标准化处理,建立研究数据集,并对数据进行清洗和预处理;其次采用Relief-F算法对特征进行选择,最终保留30个特征变量;再次选择逻辑回归、支持向量机、随机森林等3种机器学习方法进行建模分析,并采用10折交叉验证方法对分类器进行训练;最后引入准确率等模型评价指标来评估各算法在数据集上的分类预测效果。实验结果表明:随机森林的分类效果在该研究数据集上的表现最佳,准确率达到81.97%,精确率为86.90%,召回率为82.14%,F1值为0.8441。该研究提出的方法能够客观反映患者术后死亡风险,为心血管介入患者术后死亡风险预测提供了一种有效的解决方案。 展开更多
关键词 心血管介入 术后死亡风险预测 relief-F算法 特征提取 机器学习 随机森林
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Electric-controlled pressure relief valve for enhanced safety in liquid-cooled lithium-ion battery packs
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作者 Yuhang Song Jidong Hou +6 位作者 Nawei Lyu Xinyuan Luo Jingxuan Ma Shuwen Chen Peihao Wu Xin Jiang Yang Jin 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第3期98-109,I0004,共13页
The liquid-cooled battery energy sto rage system(LCBESS) has gained significant attention due to its superior thermal management capacity.However,liquid-cooled battery pack(LCBP) usually has a high sealing level above... The liquid-cooled battery energy sto rage system(LCBESS) has gained significant attention due to its superior thermal management capacity.However,liquid-cooled battery pack(LCBP) usually has a high sealing level above IP65,which can trap flammable and explosive gases from battery thermal runaway and cause explosions.This poses serious safety risks and challenges for LCBESS.In this study,we tested overcharged battery inside a commercial LCBP and found that the conventionally mechanical pressure relief valve(PRV) on the LCBP had a delayed response and low-pressure relief efficiency.A realistic 20-foot model of an energy storage cabin was constructed using the Flacs finite element simulation software.Comparative studies were conducted to evaluate the pressure relief efficiency and the influence on neighboring battery packs in case of internal explosions,considering different sizes and installation positions of the PRV.Here,a newly developed electric-controlled PRV integrated with battery fault detection is introduced,capable of starting within 50 ms of the battery safety valve opening.Furthermore,the PRV was integrated with the battery management system and changed the battery charging and discharging strategy after the PRV was opened.Experimental tests confirmed the efficacy of this method in preventing explosions.This paper addresses the safety concerns associated with LCBPs and proposes an effective solution for explosion relief. 展开更多
关键词 Pressure relief valve Liquid-cooled battery pack Explosion Flacs
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Impacts of radiation therapy on quality of life and pain relief in patients with bone metastases
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作者 Armin Hoveidaei Mehdi Karimi +2 位作者 Vida Khalafi Patrick Fazeli Amir Human Hoveidaei 《World Journal of Orthopedics》 2024年第9期841-849,共9页
Bone metastases(BM)are a common complication in advanced cancer patients,significantly contributing to morbidity and mortality due to their ability to cause pain,fractures,and spinal cord compression.Radiation therapy... Bone metastases(BM)are a common complication in advanced cancer patients,significantly contributing to morbidity and mortality due to their ability to cause pain,fractures,and spinal cord compression.Radiation therapy(RT)is vital in managing these complications by targeting metastatic lesions to ease pain,improve mobility,and reduce the risk of skeletal-related events such as fractures.Evidence supports the effectiveness of RT in pain relief,showing its ability to provide significant palliation and lessen the need for opioid painkillers,thereby enhancing the overall quality of life(QoL)for patients with BM.However,optimizing RT outcomes involves considerations such as the choice of radiation technique,dose fractionation schedules,and the integration of supportive care measures to mitigate treatment-related side effects like fatigue and skin reactions.These factors highlight the importance of personalized treatment planning tailored to individual patient needs and tumor characteristics.This mini-review aims to provide comprehensive insights into the multifaceted impacts of RT on pain management and QoL enhancement in BM patients,with implications for refining clinical practices and advancing patient care through the synthesis of findings from various studies. 展开更多
关键词 Radiation therapy RADIOTHERAPY Quality of life Pain relief Bone metastases Bone cancer
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Stress Relief Measurements in Young Adults and Adolescents—A Comparative Pilot Study with Different Relaxation Programs
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作者 Andrea Bevelaqua Claus Muss 《Open Journal of Preventive Medicine》 2024年第6期131-142,共12页
Background: Chronic stress is a emotional challenge. Constant pressure presents a serious risk of damage to mental and physical health and hence is associated with increased incidence of various diseases. The ability ... Background: Chronic stress is a emotional challenge. Constant pressure presents a serious risk of damage to mental and physical health and hence is associated with increased incidence of various diseases. The ability to cope with chronic stress may be a function of psychological resilience including intellectual capacities, but more so of external factors such as life experience and education. Adolescents are more vulnerable to chronic stress than adults. The measures introduced during the COVID-19 pandemic brought up major societal problems. As both children and adolescents lost their life anchors, the prevalence of stress in adolescents increased from 20% to 45%. Chronic psychological stress can impede the normal development of schoolchildren. It may cause anxiety, social withdrawal, interpersonal conflicts and aggression. This applies particularly to those in puberty, with the adolescent already facing unstable social bonds and elevated fear about the future. It is likely that the puberty cohort accounts for the dramatic increase in the prevalence of stress. Since it impacts public health, chronic stress among school-age children is increasingly taking on a socio-political dimension. Non-clinical stress intervention studies can investigate how to achieve stress reduction in school children. Methods: In a small pilot study, we analysed the effects of a training program with four different standard interventions, i.e. mindfulness training, progressive muscle reflection, autogenic training, and sound meditation. We obtained baseline scores of 10 stress-indicators, and re-tested after the interventions were performed. Results: The four applied interventions resulted in a reduction of 8 (out of 10) stress-indicators, such as “feeling stressed” or stress related symptoms (headaches, dizziness, sweating). This positive impact of the interventions significantly reduced “Fears about the future” (p Discussion: School children recognise the positive potential of stress reducing training or interventions. Our results provide evidence in support of integrating the training of relaxation techniques in the school curriculum. We propose that a larger study be undertaken to determine which methods would be most effective. 展开更多
关键词 Stress in Children and Young Adults Comparison of Different Stress relief Interventions in a Cohort of Pupils
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Palliative care with adequate pain relief challenges the need for euthanasia legislation
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作者 Renald Blundell Martina Cini Kimberley Blundell 《History & Philosophy of Medicine》 2024年第2期6-13,共8页
Background:In today’s society the ongoing discussion about euthanasia triggers emotionally charged debates surrounding the delicate balance between valuing life and respecting an individual’s autonomy.With the persi... Background:In today’s society the ongoing discussion about euthanasia triggers emotionally charged debates surrounding the delicate balance between valuing life and respecting an individual’s autonomy.With the persistence of this debate,there has been the emergence of the concept of the so-called alternative:palliative care.Positioned as a substitute for euthanasia,palliative care aims to alleviate suffering in terminally ill patients without engaging in the ethical dilemmas associated with euthanasia.Methods:This paper explores the facets of palliative care highlighting its core objectives such as providing adequate pain relief as a compassionate alternative to euthanasia.Results:By examining palliative care as a comprehensive approach to end of life support,this study challenges the perceived necessity of euthanasia and advocates,for compassionate and dignified end of life experiences.Conclusion:In conclusion,palliative care emerges as a viable and ethically sound alternative to euthanasia,emphasizing the importance of compassionate end-of-life care and pain management. 展开更多
关键词 palliative care adequate pain relief euthanasia legislation end-of-life care patient-centered care policy development
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Application of STEEP and Interpretive Structural Modeling in the Design Imagery of Taiwan Public Ceramic Relief Murals
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作者 Chuan-Chin Chen Jiann-Sheng Jiang Shaolei Zhou 《Journal of Contemporary Educational Research》 2024年第5期117-127,共11页
Ceramic relief mural is a contemporary landscape art that is carefully designed based on human nature,culture,and architectural wall space,combined with social customs,visual sensibility,and art.It may also become the... Ceramic relief mural is a contemporary landscape art that is carefully designed based on human nature,culture,and architectural wall space,combined with social customs,visual sensibility,and art.It may also become the main axis of ceramic art in the future.Taiwan public ceramic relief murals(PCRM)are most distinctive with the PCRM pioneered by Pan-Hsiung Chu of Meinong Kiln in 1987.In addition to breaking through the limitations of traditional public ceramic murals,Chu leveraged local culture and sensibility.The theme of art gives PCRM its unique style and innovative value throughout the Taiwan region.This study mainly analyzes and understands the design image of public ceramic murals,taking Taiwan PCRM’s design and creation as the scope,and applies STEEP analysis,that is,the social,technological,economic,ecological,and political-legal environments are analyzed as core factors;eight main important factors in the artistic design image of ceramic murals are evaluated.Then,interpretive structural modeling(ISM)is used to establish five levels,analyze the four main problems in the main core factor area and the four main target results in the affected factor area;and analyze the problem points and target points as well as their causal relationships.It is expected to sort out the relationship between these factors,obtain the hierarchical relationship of each factor,and provide a reference basis and research methods. 展开更多
关键词 Interpretive structural modeling(ISM) STEEP analysis Public ceramic relief murals(PCRM)
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半监督Relief-F特征选择算法 被引量:2
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作者 靳炳烨 王锋 魏巍 《河北师范大学学报(自然科学版)》 CAS 2023年第4期348-353,共6页
数据规模的不断增加,使得为数据库中全部样本做标记变得尤为困难,数据集也因此呈现出了明显的弱标记性.为此,针对大规模少数标记数据集的特征选择问题,基于经典的Relief-F算法,通过综合考虑有标记样本与无标记样本对数据样本近邻的影响... 数据规模的不断增加,使得为数据库中全部样本做标记变得尤为困难,数据集也因此呈现出了明显的弱标记性.为此,针对大规模少数标记数据集的特征选择问题,基于经典的Relief-F算法,通过综合考虑有标记样本与无标记样本对数据样本近邻的影响,重新定义样本近邻的搜索策略,提出了一种面向符号数据的半监督特征选择算法.为进一步分析新算法的有效性,仿真实验中选取了5组UCI数据集,并引入机器学习中3个常用分类器对新算法和对比算法的特征选择结果的分类性能作了分析和比较,实验结果很好地验证了本文中提出的新算法的有效性和可行性. 展开更多
关键词 特征选择 relief-F算法 半监督学习 距离度量
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Effect of Dynamic Pressure Feedback Orifice on Stability of Cartridge-Type Hydraulic Pilot-Operated Relief Valve
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作者 Yaobao Yin Dong Wang +1 位作者 Junyong Fu Hong-chao Jian 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第4期227-241,共15页
Current research on pilot-operated relief valve stability is primarily conducted from the perspective of system dynamics or stability criteria,and most of the existing conclusions focus on the spool shape,damping hole... Current research on pilot-operated relief valve stability is primarily conducted from the perspective of system dynamics or stability criteria,and most of the existing conclusions focus on the spool shape,damping hole size,and pulsation frequency of the pump.However,the essential factors pertaining to the unstable vibration of relief valves remain ambiguous.In this study,the dynamic behavior of a pilot-operated relief valve is investigated using the frequency-domain method.The result suggests that the dynamic pressure feedback orifice is vital to the dynamic characteristics of the valve.A large orifice has a low flow resistance.In this case,the fluid in the main spring chamber flows freely,which is not conducive to the stability of the relief valve.However,a small orifice may create significant flow resistance,thus restricting fluid flow.In this case,the oil inside the main valve spring chamber is equivalent to a high-stiffness liquid spring.The main mass-spring vibration system has a natural frequency that differs significantly from the operating frequency of the relief valve,which is conducive to the stability of the relief valve.Good agreement is obtained between the theoretical analysis and experiments.The results indicate that designing a dynamic pressure feedback orifice of an appropriate size is beneficial to improving the stability of hydraulic pilot-operated relief valves.In addition,the dynamic pressure feedback orifice reduces the response speed of the relief valve.This study comprehensively considers the stability,rapidity,and immunity of relief valves and expands current investigations into the dynamic characteristics of relief valves from the perspective of classical control theory,thus revealing the importance of different parameters. 展开更多
关键词 Pilot-operated relief valve Dynamic pressure feedback orifice STABILITY RAPIDITY IMMUNITY
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基于Relief算法的智能车辆牌照模糊识别方法
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作者 刘洋宇 《吉林大学学报(信息科学版)》 CAS 2023年第1期158-164,共7页
由于当前已有方法未能对车牌照进行降维处理,导致车牌照识别结果不准确,为此,提出一种基于Relief算法的智能车辆牌照模糊识别方法。采用Relief算法计算不同车牌图像特征的权重系数,对特征集进行降维处理。通过序列视频图像对智能车牌进... 由于当前已有方法未能对车牌照进行降维处理,导致车牌照识别结果不准确,为此,提出一种基于Relief算法的智能车辆牌照模糊识别方法。采用Relief算法计算不同车牌图像特征的权重系数,对特征集进行降维处理。通过序列视频图像对智能车牌进行增强处理,利用全卷积网络对车牌照显著区域进行检测,粗略提取图像中的显著区域,使用滑动窗方法对候选区域车牌进行精准检测,定位车牌准确位置,加入字符的上下文信息,对字符进行精确检测和识别,最终实现智能车辆牌照模糊识别。仿真实验结果表明,所提方法可获取高精度的车牌照识别结果。 展开更多
关键词 relief算法 智能车辆牌照 模糊识别 显著区域检测 图像增强
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Investigating the Physiological Mechanisms between Resistance Training and Pain Relief in the Cancer Population: A Literature Review
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作者 Yvonne Jiang Peter C. Angeletti Amy J. Hoffman 《Journal of Cancer Therapy》 CAS 2023年第2期80-101,共22页
This literature review examines the mechanisms of how exercise, specifically in the form of resistance training, may lead to pain relief in the cancer population. Primary data from three different cancer populations: ... This literature review examines the mechanisms of how exercise, specifically in the form of resistance training, may lead to pain relief in the cancer population. Primary data from three different cancer populations: breast, prostate, and lung, will be examined. A number of experimental studies have been conducted to confirm the effectiveness of resistance training on pain relief as well as the biochemical pathways that relate to this process. In this review, we will examine 5 randomized controlled trials. For the purposes of this review, pain is defined as physical suffering or discomfort associated with illness. Pain is the body’s natural signal, bringing attention to damage that has been sustained by tissues. However, chronic pain is common in the cancer population, and often serves no good purpose but instead will negatively impact both physical and mental health. The three types of pain: nociceptive, neuropathic, and inflammatory pathways have been investigated, and the knowledge of pain mechanisms allows for the understanding of how it is associated with pain. The purpose of this exploratory literature review is to give insight on how to maximize pain-relieving effects of resistance training. Research has indicated that resistance training modulates pain pathways by upregulating the release of pain-relieving substances including beta-endorphins, anti-inflammatory cytokines, and endocannabinoids. Understanding of the benefits of resistance training may be useful in relieving cancer pain, and reproducing effects of pain-relieving strategies while minimizing the symptoms related to cancer and its treatment. 展开更多
关键词 Lung Cancer Breast Cancer Prostate Cancer Exercise Physical Activity CANCER PAIN SYMPTOMS Pain relief Resistance Training Pain relief Biochemical Pathway
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基于Relief-PGS优化算法的数据分类
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作者 张菡玫 《河南科技》 2023年第24期31-35,共5页
【目的】在选取图像特征对图像进行分类时,选取的特征属性是否冗余会影响到图像分类的正确率。为提高分类的准确率,使用Relief-PGS优化算法对特征子集和支持向量机参数同步进行优化。【方法】首先使用Relief算法对特征数据集进行筛选,... 【目的】在选取图像特征对图像进行分类时,选取的特征属性是否冗余会影响到图像分类的正确率。为提高分类的准确率,使用Relief-PGS优化算法对特征子集和支持向量机参数同步进行优化。【方法】首先使用Relief算法对特征数据集进行筛选,其次将筛选出的特征子集数目和支持向量机参数一起编码到粒子群-遗传算法中进行同步优化,最后对处理后的数据集进行分类,能有效提高分类的准确率。【结果】选取UCI数据库中的5种数据集进行分类,与传统的SVM算法、PGS算法和Relief-SVM算法相比,Relief-PGS优化算法对图像分类的准确率分别提高了22.53%、6.05%和11.16%。【结论】研究结果表明,Relief-PGS算法在去掉不重要特征的同时,对支持向量机参数进行优化,能有效提高分类的准确率。 展开更多
关键词 特征选择 relief算法 遗传-粒子群算法 支持向量机
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不平衡数据集上的Relief特征选择算法 被引量:15
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作者 菅小艳 韩素青 崔彩霞 《数据采集与处理》 CSCD 北大核心 2016年第4期838-844,共7页
Relief算法为系列特征选择方法,包括最早提出的Relief算法和后来拓展的ReliefF算法,核心思想是对分类贡献大的特征赋予较大的权值;特点是算法简单,运行效率高,因此有着广泛的应用。但直接将Relief算法应用于有干扰的数据集或不平衡数据... Relief算法为系列特征选择方法,包括最早提出的Relief算法和后来拓展的ReliefF算法,核心思想是对分类贡献大的特征赋予较大的权值;特点是算法简单,运行效率高,因此有着广泛的应用。但直接将Relief算法应用于有干扰的数据集或不平衡数据集,效果并不理想。基于Relief算法,提出一种干扰数据特征选择算法,称为阈值-Relief算法,有效消除了干扰数据对分类结果的影响。结合K-means算法,提出两种不平衡数据集特征选择算法,分别称为K-means-ReliefF算法和K-means-Relief抽样算法,有效弥补了Relief算法在不平衡数据集上表现出的不足。实验证明了本文算法的有效性。 展开更多
关键词 特征选择 relief算法 reliefF算法 不平衡数据集
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New Challenges For International Disaster Relief
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作者 Qiu Hui 《China Report ASEAN》 2023年第2期54-57,共4页
The Türkiye-Syria earthquake is pushing global search and rescue capacity to the limit On February 6,a powerful earthquake and a series of strong aftershocks struck southern Türkiye near the Syrian border.In... The Türkiye-Syria earthquake is pushing global search and rescue capacity to the limit On February 6,a powerful earthquake and a series of strong aftershocks struck southern Türkiye near the Syrian border.International assistance has since poured into the disaster-hit areas.According to Turkish Foreign Minister Mevlut Cavusoglu,as of February 18,102 countries had offered humanitarian aid and rescue teams from 88 countries participated in search and rescue operations in Türkiye. 展开更多
关键词 EARTHQUAKE DISASTER relief
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Multi-Symptom Relief for Cough & Cold: Benefits of Adding Vicks VapoRub to the Treatment Regimen
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作者 Delyth Whiteford Juana Rios +1 位作者 David Hengehold Sue Aspley 《Open Journal of Respiratory Diseases》 2023年第2期9-27,共19页
Background: The common cold is inarguably a multi-symptom syndrome. Thus, patients commonly use several medicinal products simultaneously to treat a range of co-existing clinical manifestations. Topical ointments... Background: The common cold is inarguably a multi-symptom syndrome. Thus, patients commonly use several medicinal products simultaneously to treat a range of co-existing clinical manifestations. Topical ointments with medicated vapours are a popular and effective treatment for the relief of various respiratory tract symptoms. Vicks VapoRub (VVR), a paraffin-based therapeutic ointment containing levomenthol, eucalyptus oil, turpentine oil and camphor, is frequently combined with other cough and cold treatments. However, little is known about which medications are commonly taken together and how patients experience the combined efficacy. Methods: A 20-question online survey to assess habits and beliefs amongst cold sufferers was conducted using the Toluna Start platform. A total of 1513 adults that had suffered from a cold or mild COVID-19 infection in the preceding 12 months were recruited from five European countries. Results: Most cold sufferers combined VVR with other cold medicines, such as paracetamol (75.9%), multi-symptom relief (MSR) products (64.0%) or nasal decongestants (57.0%) to treat their symptoms. VVR was mainly used topically, at night, and on days 3 - 4 of the disease. The addition of VVR to the treatment regimen was perceived as highly effective at relieving multiple cold symptoms. Furthermore, improved sleep and a free breathing sensation were attributed to VVR when used in combination with other cold remedies. Statements on VVR regarding effectiveness, sleep, sleep + effectiveness, speed of action and user satisfaction were agreed upon by a total of 74.8% to 88.3% of panellists. Conclusion: Our survey confirms that in Europe, VVR is commonly used as part of a regimen to manage cold symptoms, and contributes to better overall perceived relief as part of a multi-facetted treatment approach. Prospective clinical data are needed to further confirm these results. 展开更多
关键词 Common Cold Vicks VapoRub Therapeutic Ointment Survey Multi-Symptom relief
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Rapturous Relief
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作者 ALAFATI MUGABO 《ChinAfrica》 2023年第3期38-38,共1页
China has cancelled Rwanda’s $7.1-million loan used for building a road Residents in the Masaka and Kabuga suburbs of Rwanda’s capital Kigali were happy to learn that the Chinese government has decided to cancel the... China has cancelled Rwanda’s $7.1-million loan used for building a road Residents in the Masaka and Kabuga suburbs of Rwanda’s capital Kigali were happy to learn that the Chinese government has decided to cancel the debt used for the construction of a road in their locality. 展开更多
关键词 decided relief LOCALITY
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基于Relief-WGS优化算法的图像分类方法
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作者 纪峰 马圆月 刘莹 《数字技术与应用》 2023年第11期5-8,共4页
针对图像特征选择问题,特征属性过多不但会造成维数灾难,而且会影响分类的正确率。在采用支持向量机分类时,特征维数较高,会造成分类准确率较低,运算速度较慢等问题。为了解决此问题,提出Relief算法、鲸鱼算法、遗传算法和支持向量机相... 针对图像特征选择问题,特征属性过多不但会造成维数灾难,而且会影响分类的正确率。在采用支持向量机分类时,特征维数较高,会造成分类准确率较低,运算速度较慢等问题。为了解决此问题,提出Relief算法、鲸鱼算法、遗传算法和支持向量机相结合的ReliefWGS优化算法,实现图像特征选择和分类。 展开更多
关键词 relief算法 支持向量机 分类准确率 图像分类 图像特征选择 运算速度 特征属性 维数灾难
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基于Relief特征量优化及SOM网络的断路器操作机构状态评估 被引量:13
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作者 张浩 赵莉华 +5 位作者 景伟 阳薇 姜海洋 朱林林 荣强 付荣荣 《高压电器》 CAS CSCD 北大核心 2017年第9期240-246,共7页
为提高断路器操作机构状态评估的效率及准确性,文中提出了采用Relief优化方法对分合闸线圈电流特征向量进行优化及SOM网络对线圈电流样本进行分类的高压断路器操作机构状态评估方法。仿真研究结果表明:基于Relief的分合闸线圈电流特征... 为提高断路器操作机构状态评估的效率及准确性,文中提出了采用Relief优化方法对分合闸线圈电流特征向量进行优化及SOM网络对线圈电流样本进行分类的高压断路器操作机构状态评估方法。仿真研究结果表明:基于Relief的分合闸线圈电流特征向量优化方法和SOM网络分类方法的操作机构状态评估能够实现操作机构状态的准确评估,同时采用优化后的电流特征向量数据进行状态评估减小了运算量和缩短了运算时间,提高了断路器机构状态评估的效率。 展开更多
关键词 relief 状态评估 特征向量 操作机构 SOM
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基于GF-1遥感影像和relief-mRMR-GASVM模型的小麦白粉病监测 被引量:12
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作者 黄林生 阮超 +3 位作者 黄文江 师越 彭代亮 丁文娟 《农业工程学报》 EI CAS CSCD 北大核心 2018年第15期167-175,314,共10页
选择合适的建模和特征选择算法对提高作物病害的遥感监测水平有着重要的作用。研究以河北省小麦白粉病为研究对象,基于GF-1/WFV数据共提取了4个波段反射率数据和10个对作物长势和胁迫敏感的植被指数作为初选特征。针对常用的特征提取算... 选择合适的建模和特征选择算法对提高作物病害的遥感监测水平有着重要的作用。研究以河北省小麦白粉病为研究对象,基于GF-1/WFV数据共提取了4个波段反射率数据和10个对作物长势和胁迫敏感的植被指数作为初选特征。针对常用的特征提取算法relief算法筛选出的特征存在冗余性的问题,提出了一种relief结合最小冗余最大相关(minimum redundancy maximum relevance,m RMR)的特征降维算法(relief-m RMR)。首先,通过relief算法计算出各特征的权重系数,对特征集进行加权;然后利用m RMR算法选出与类别具有最小冗余性的特征,利用支持向量机(support vector machine,SVM)对河北白粉病进行监测,并用遗传算法(genetic algorithm,GA)优化的SVM(GASVM)建立了白粉病的监测模型(relief-m RMR-GASVM),将监测结果分别与SVM和网格寻优(grid search,GS)算法优化的SVM(GSSVM)的监测结果进行对比分析,同时比较了该方法与Ada Boost、粒子群(Pso)优化的最小二乘支持向量机(least squares support vector machine,Pso-LSSVM)和随机森林(random forest,RF)3种方法的优越性。结果表明,relief-m RMR算法筛选出的特征与GASVM、SVM和GSSVM建立的监测模型精度比传统relief算法筛选特征所建模型的精度分别提高了14.3个百分点、7.2个百分点和7.1个百分点,比传统m RMR算法筛选特征所建模型的精度分别提高了14.3个百分点、14.3个百分点和14.2个百分点。relief-m RMR算法结合GASVM建立的监测模型精度为所有模型中最高,精度为85.7个百分点,分别比SVM和GSSVM所建监测模型精度提高了21.4个百分点和7.2个百分点。此外,GF-1数据结合relief-m RMR-GASVM模型的监测精度分别高出Ada Boost、Pso-LSSVM和RF方法21.4个百分点、14.3个百分点和7.1个百分点。说明GF-1数据结合relief-m RMR-GASVM模型可用于小麦白粉病的遥感监测。 展开更多
关键词 病害 遥感 监测 小麦 白粉病 支持向量机 relief算法 mRMR算法
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基于ReliefF和PSO混合特征选择的面向对象土地利用分类 被引量:56
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作者 肖艳 姜琦刚 +3 位作者 王斌 李远华 刘舒 崔璨 《农业工程学报》 EI CAS CSCD 北大核心 2016年第4期211-216,共6页
针对面向对象土地利用分类存在特征维数过高的问题,提出了一种结合Relief F和粒子群优化算法(particle swarm optimization,PSO)的混合特征选择方法,即首先利用Relief F作为特征预选器滤除相关性小的特征,然后以PSO作为搜索算法,以支持... 针对面向对象土地利用分类存在特征维数过高的问题,提出了一种结合Relief F和粒子群优化算法(particle swarm optimization,PSO)的混合特征选择方法,即首先利用Relief F作为特征预选器滤除相关性小的特征,然后以PSO作为搜索算法,以支持向量机(support vector machine,SVM)的分类精度作为评估函数在剩余特征中选择出最优特征子集。该文以吉林省长春市部分区域为研究区,采用Landsat8遥感影像为数据源,首先对其进行多尺度分割,然后提取影像对象的光谱、纹理、形状和空间关系特征,利用提出的混合特征选择方法选取最优特征子集,最后使用SVM分类器对研究区进行土地利用分类,总体分类精度和Kappa系数分别为85.88%和0.8036,与基于4种其他特征选择方法的土地利用分类结果进行比较,基于Relief F和PSO的混合特征选择方法利用最少的特征获得最高的分类精度,能够有效地用于面向对象土地利用分类。 展开更多
关键词 土地利用 分类 支持向量机 特征选择 面向对象 reliefF 粒子群优化算法
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极大熵Relief特征加权 被引量:9
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作者 张翔 邓赵红 +1 位作者 王士同 蔡及时 《计算机研究与发展》 EI CSCD 北大核心 2011年第6期1038-1048,共11页
Relief特征加权的最新研究进展表明其可近似地表述为一个间距最大化优化问题.尽管该类算法广为应用,但仍然存在一些缺陷.为了提高Relief特征加权的适应性和鲁棒性,融合间距最大化和极大熵理论,并由此探讨了新的鲁棒的具有更好适应性的Re... Relief特征加权的最新研究进展表明其可近似地表述为一个间距最大化优化问题.尽管该类算法广为应用,但仍然存在一些缺陷.为了提高Relief特征加权的适应性和鲁棒性,融合间距最大化和极大熵理论,并由此探讨了新的鲁棒的具有更好适应性的Relief特征加新方法.首先,构造了一个结合极大熵原理的间距最大化目标函数.对于该目标函数,运用优化理论得到一些重要的理论结果.在此基础上,对于两类数据、多类数据和在线数据,提出了一组鲁棒的Relief特征加权算法.利用UCI基准数据集和基因数据集进行了实验验证,结果表明提出的新Relief特征加权算法对噪音和例外点显示出了更好的适应性和鲁棒性. 展开更多
关键词 relief算法 特征选择 特征加权 间距最大化原则 极大熵
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