Determination of Weak Points Based on Risk Theory and Application to Transmission Network Planning

In the traditional power transmission network planning,deterministic analysis methods are widely used.In such methods,all contingencies are deemed to have the same occurrence probability,which is not reasonable.In this paper,risk assessment is introduced to the process of transmission network planning considering the probabilistic characteristics of contingencies.Risk indices are given to determine the weak points of the transmission network based on local information,such as bus risk,line overload risk,contingency severity.The indices are calculated by the optimal cost control method based on risk theory,which can help planners to quickly determine weak points in the planning and find solution to them.For simplification,only line overload violation is considered.Finally,the proposed method is validated by an IEEE-RTS test system and a real power system in China from two aspects.In the first case,the original system is evaluated by the proposed method to find the weak points,and then four planning schemes are established,among which the best scheme is selected.In the second case,four initial planning schemes are established by combining the experiences of planners,and after the evaluation by using the proposed method,the best planning scheme is improved based on the information of weak points in the initial schemes,and the risk of improved scheme is reduced from 42 531.86 MW·h per year to 4 431.26 MW·h per year.

Risk factors affecting the mother-to-infant transmission of hepatitis B virus: a meta analysis

Objective:To search for risk factors that affect mother-to-infant transmission of hepatitis B virus (HBV). Methods: To obtain studies eligible for meta-analysis, China biological medicine discs and MEDLINE citations were surveyed. Mother HBV DNA or HBeAg positivity, neonate HBeAg positivity, mode of delivery, threatened abortion and threatened premature labor were processed with meta analysis. Criteria for selection of published studies for meta analysis were based on principle by Abdolmaleky HM[1]. Odds ratio (OR) was calculated and summarized by fixed effect model or random-effects model using RevMan software. The heterogeneity of the group of ORs was assessed using an x2 test. The significance of the pooled OR was determined by the u-test. The strength of association was assessed using the OR. An OR>1. 0 indicated a positive association between the risk factor and neonate HBV infection. Results: After meta analysis of factors concerned, a significant association was found between the positivity of HBeAg in mother and neonate, of HBV DNA in mother peripheral serum, and HBV mother-to-infant transmission, with a pooled OR equal to 19.43 (95% CI=8. 77-43. 06), 36.5 (95% 01=19.85-67.11), and 36. 5 (95% CI=19. 85-67. 11) respectively. Mode of delivery, threatened abortion and threatened premature labor proved not to be of risk factors on the mother-to-infant transmission of HBV. Conclusion: Mother HBV DNA or HBeAg positivity and neonate HBeAg positivity were proved to be of risk factors affecting the transmission of HBV from mother to fetal.

Review of the risk factors for SARS-CoV-2 transmission

The severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)pandemic,which has lasted for nearly a year,has made people deeply aware of the strong transmissibility and pathogenicity of SARS-CoV-2 since its outbreak in December 2019.By December 2020,SARS-CoV-2 had infected over 65 million people globally,resulting in more than 1 million deaths.At present,the exact animal origin of SARS-CoV-2 remains unclear and antiviral vaccines are now undergoing clinical trials.Although the social order of human life is gradually returning to normal,new confirmed cases continue to appear worldwide,and the majority of cases are sporadic due to environmental factors and lax self-protective consciousness.This article provides the latest understanding of the epidemiology and risk factors of nosocomial and community transmission of SARS-CoV-2,as well as strategies to diminish the risk of transmission.We believe that our review will help the public correctly understand and cope with SARS-CoV-2.

Risk Factors in the Transmission of Tuberculosis in Nairobi: A Descriptive Epidemiological Study

Background: Tuberculosis is an infectious disease with an estimated 1.45 million deaths every year. Many patients get infected as a result of ignorance of the risk factors that contribute to disease transmission. Methodology: A descriptive epidemiological study was conducted on 258 patients presenting with pulmonary tuberculosis. Patients’ sputa were collected for laboratory analysis and patients were required to respond to a structured questionnaire on risk factors for transmission. Data among stratified groups were compared using bivariate analysis. Statistical significance was considered at p Results: There were significantly more males than females associated with pulmonary tuberculosis infection (χ2 = 0.963;df = 1;p (64.3%) patients were living in single rooms with 110 (42.6%) living with more than two people with a maximum of 10 people in a single room. Only 73 (28.3%) were living alone in a single room and only 7 families (2.7%) were living in houses with five or more rooms. Alcohol consumers and smokers were 102 (39.5%) and 93 (36%) respectively. Half of the patients (137 (53.3%)) had not completed secondary education with only 16 (6.2%) having completed tertiary education. Recurrent cases were 54 (21%) while those exposed to the disease either at home or working place were 75 (29.2%). Out of 171 patients who agreed to test for HIV, 46 (26.9%) were positive. Marital status had no effect on incidence of disease. Conclusion: Emphasis should be given to creating awareness of the risk factors associated with transmission of tuberculosis in order to reduce the rate of infection.

Guidelines on Risk Factors for HIV Transmission Are Conflicting

According to current guidelines, exposing mucous membrane to blood and body fluids of HIV infected people is risk of transmission. About 30% - 80% of HIV infected people have at least one oral manifestation. The most frequently occurring oral manifestations (pseudomembranous candidiasis, linear gingival erythema, etc.) give rise to bleeding either spontaneously or after stimulation, and strenuous stirring during oral sex and deep-mouth kissing increase risk of bleeding from oral manifestations, exposing oral and genital mucous membrane of partners to the blood. However, current guidelines assert that there’s little to no risk of getting HIV from oral sex and deep-mouth kissing. These guidelines are conflict with each other, suggesting potential problems with current prevention strategies which are based on the guidelines. After discussing existing data on animals, lesbians, young peoples, and occupational exposures, this paper suggests oral sex and deep-mouth kissing are risk factors when one partner has HIV-associated oral bleeding manifestations, and the number of infections associated with oral sex and deep-mouth kissing is significant. Current guidelines on HIV risk factors should be reevaluated urgently, and new studies should be undertaken with an open mind to explore risk factors.

Systematized Literature Review on Spatial Analysis of Environmental Risk Factors of Malaria Transmission

Malaria is still the major parasitic disease in the world, with approximately 438,000 deaths in 2015. Environmental risk factors (ERF) have been widely studied, however, there are discrepancies in the results about their influence on malaria transmission. Recently, papers have been published about geospatial analysis of ERF of malaria to explain why malaria varies from place to place. Our primary objective was to identify the environmental variables most used in the geospatial analysis of malaria transmission. The secondary objective was to identify the geo-analytic methods and techniques, as well as geo-analytic statistics commonly related to ERF and malaria. We conducted a systematized review of articles published from January 2004 to March 2015, within Web of Science, Pubmed and LILACS databases. Initially 676 articles were found, after inclusion and exclusion criteria, 29 manuscripts were selected. Temperature, land use and land cover, surface moisture and vector breeding site were the most frequent included variables. As for geo-analytic methods, geostatistical models with Bayesian framework were the most applied. Kriging interpolations, Geographical Weighted Regression as well as Kulldorff’s spatial scan were the techniques more widely used. The main objective of many of these studies was to use these methods and techniques to create malaria risk maps. Spatial analysis performed with satellite images and georeferenced data are increasing in relevance due to the use of remote sensing and Geographic Information System. The combination of these new technologies identifies ERF more accurately, and the use of Bayesian geostatistical models allows a wide diffusion of malaria risk maps. It is known that temperature, humidity vegetation and vector breeding site play a critical role in malaria transmission;however, other environmental risk factors have also been identified. Risk maps have a tremendous potential to enhance the effectiveness of malaria-control programs.

Ecology, Distribution and Risk of Transmission of Viral Haemorrhagic Fevers by Aedes Mosquitoes around the Port Areas of Tema in Southern Ghana

Aedes-borne diseases remain a public health challenge for many countries globally. The extent of spread of invasive species of Aedes mosquitoes and risk of transmission of the diseases especially around the point of entry of goods such as ports is not well known in Ghana. This study investigated the ecology, distribution and risk of transmission of viral haemorrhagic fevers by Aedes mosquitoes around the port areas of Tema, Southern Ghana. The mosquitoes from this study were collected using human landing catches, ovitraps and larval collections for a period of six months. A total of 1092 containers were inspected in both seasons and of these, 237 (21.7%) were positive for mosquito larvae or pupae in rainy season while 181 (16.6%) were positive in dry season. A total of 6498 mosquitoes were collected and identified morphologically using taxonomic keys. 6038 (92.9%) were Aedes aegypti, 337 (5.2%) were Culex spp. and 123 (1.9%) were Anopheles gambiae. The Ae. aegypti larvae were found breeding in a series of water-holding containers which included disposed plastic containers, earthenware pots, car tyres, plastic barrels, plastic basins, buckets, metal drums, jerrycans and poly tank. A high proportion of Aedes aegypti eggs were found in the ovitraps during the rainy season than in the dry season in the study sites. Ae. aegypti was the most common mosquitoes biting mostly outdoors (65.6%) with more bites occurring in the rainy season (63.6%) in the two residential sites (Tema Community One and Tema New Town). The risk of transmission of viral haemorrhagic fever in the study sites was assessed using House Index, Container Index, Breteau Index and was found to be higher in Tema New town area with seasonal variations within the sites. The man-vector contact rates for the two residential sites were also found to be higher in rainy season than the dry season. These observations indicate that the risk of transmission of viral haemorrhagic fevers in the study areas is high especially in the rainy season. The implications of the findings in the formulation of future vector control programmes around the port areas in the country are discussed in the paper.

Risk assessment of hepatitis E transmission through tissue allografts

Hepatitis E virus(HEV)is a small non-enveloped single stranded RNA virus whose genotypes 3 and 4 have been associated with zoonotic transmission in industrialized countries.HEV infection is considered the main cause of acute hepatitis worldwide.In some cases,transfusion of blood components or organ transplantation have been reported as the source of infection.We have conducted a literature review on the risk of transmission through cell and tissue allografts.Although no case was found,measures to control this risk should be taken when donor profile(based upon geographical and behavioural data)recommended it.Issues to be considered in donor screening and tissue processing to assess and to reduce the risk of HEV transmission are approached.

Risks of Viral Hepatitis B Transmission in Mother-to-Infant of Pregnant Women Carriers of Chronic Viral Hepatitis B in Cote d’Ivoire

The aim of this study was to identify the risk factors of mother-to-child transmission of HBV in positive Ag Hbs pregnant women in Cote d’Ivoire. Methods: This was a transversal prospective study that took place over a period of 7 months (from February 2016 to August 2016) in 2 university hospital and 2 private clinics. We consecutively recruited 91 pregnant women who were positive for HBs Ag in prenatal consultations. For each pregnant woman record included in the study, we provided Socio-demographic (Age, marital status, education level, social rank, gravidity, parity) and biological data (HBs Ag, Anti-HBc Total Ac, Hbe Ag, Ac anti-Hbe Ac, DNA-VHB, Ac anti-HCV Ac, retroviral serology, transaminases). All of these data were collected using a survey sheet developed for the study. Results: The age of our pregnant women HBs positive ranged from 18 years to 44 years with a mean age of 30.10 years. The age group from 20 to 39 years was the most represented with a frequency of 92.31%. Almost of all positive HBs Ag pregnant women was HBe Ag negative, only 3.3% was HBe Ag positive. The viral load above 2000 IU/ml was found in 21 (23.03%) patients. There were 4 co-infected patients, which 3 HBV-HIV and 1 HBV-HCV. Only 19 (20.88%) pregnant HBs Ag positive women were able to bring back the supplementary virological assessment within a period less than one month. Conclusion: According to our work the virologic profile of positive HBs Ag in pregnant women in Cote d’Ivoire is characterized by an important viral replication objectified by a high viral load in about 23% pregnant women, a negativity of HBe antigen in 96.6% of them.

Molecular study of HCV detection,genotypes and their routes of transmission in North West Frontier Province,Pakistan

Objective:To determine hepatitis C virus(HCV) genotypes and explore the associated risk factors in chronic HCY patients.Methods:A total of 116 patients with chronic hepatitis C were subjected to polymerase chain reaction(PCR) based detection out of which 112 chronic HCV patients[53 male(47.32%),59 female(52.68%);mean age(43.76±16.40) years;mean BMI(23.8± 3.9)kg]were enrolled in this study.The frequency of 6 HCV genotypes and associated risk factors were evaluated from five districts of North West Frontier Province(NWFP).Results:Genotype 3was the most prevalent in 73 samples(65.17%) followed by genotype 1 in 24(21.42%) and genotype2 in 13(11.60%) samples.Genotype3 had significantly high prevalence(P=0.0002).The results showed that 48(42.85%) samples were infected with HCV 3a:25(22.32%) with 3b;14(12.50%) with 1a;10(8.92%)with 1b;11(9.82%) with 2a;2(1.78%) with 2b;and 2 were untypable.The distribution of HCV genotypes in Murdan.Charsadda,Peshawar.Sawabi and Nowshehra districts was different.Use of unsterile equipment lor medication,barbers and previous history of hospitalization were the main risk factors for HCV transmission.Conclusions:Cenotype 3a and 3b.1a.1b and 2a are the common genotypes in NWFP.Genotype 4.5.and 6 can not be found in a single sample.The level of awareness about various modes ot transmission of HCV among the population is found to be verv low.

Basic Concept and Theoretical Study of Condition-based Maintenance for Power Transmission System

状态检修背景下,为解决电网运行整体与输变电设备个体之间的矛盾和冲突,在已有研究成果基础上,提出电网状态检修的概念,在输变电设备状态检修决策过程中,给出电网故障风险和电网检修风险的定义以及相应的量化表达式。依据设备状态预测,以电网故障风险和电网检修风险的和最小为目标,将设备检修、运行以及电网整体性能在概率引导下相互牵制,形成电网状态检修的数学模型,并给出相应的解决方法。最后,为验证该理论研究的可行性,分别以可靠性测试系统RBTS-BUS6和IEEE-RTS79系统为例,对各种情况进行分析,体现了预期的效果,并期望为电网检修与运行协调决策理论的深入研究提供必要的理论基础。

Vertically acquired hepatitis C virus infection:Correlates oftransmission and disease progression

The worldwide prevalence of hepatitis C virus(HCV)infection in children is 0.05%-0.4% in developed countries and 2%-5% in resource-limited settings, where inadequately tested blood products or un-sterile medical injections still remain important routes of infection. After the screening of blood donors, motherto-child transmission(MTCT) of HCV has become the leading cause of pediatric infection, at a rate of 5%. Maternal HIV co-infection is a significant risk factor for MTCT and anti-HIV therapy during pregnancy seemingly can reduce the transmission rate of both viruses. Conversely, a high maternal viral load is an important, but not preventable risk factor, because at present no anti-HCV treatment can be administered to pregnant women to block viral replication. Caution is needed in adopting obstetric procedures, such as amniocentesis or internal fetal monitoring, that can favor fetal exposure to HCV contaminated maternal blood, though evidence is lacking on the real risk of single obstetric practices. Mode of delivery and type of feeding do not represent significant risk factors for MTCT. Therefore, there is no reason to offer elective caesarean section or discourage breast-feeding to HCV infected parturients. Information on the natural history of vertical HCV infection is limited. The primary infection is asymptomatic in infants. At least one quarter of infected children shows a spontaneous viral clearance(SVC) that usually occurs within 6 years of life. IL-28 B polymorphims and genotype 3 infection have been associated with greater chances of SVC. In general, HCV progression is mild or moderate in children with chronic infection who grow regularly, though cases with marked liver fibrosis or hepatic failure have been described. Non-organ specific autoantibodies and cryoglobulins are frequently found in children with chronic infection, but autoimmune diseases or HCV associated extrahepatic manifestations are rare.

Demographic and risk characteristics of healthcare workers infected with SARS-CoV-2 from two tertiary care hospitals in the United Arab Emirates

BACKGROUND Understanding the transmission dynamics of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection among healthcare workers(HCWs)and their social contacts is crucial to plan appropriate risk-reduction measures.AIM To analyze the socio-demographic risk factors and transmission of SARS-CoV-2 infection among HCWs in two tertiary care hospitals in Dubai,United Arab Emirates.METHODS The demographic and clinical characteristics were available for all HCWs in both facilities from the human resources department.A cross-sectional survey was conducted from January-April 2022 among HCWs who tested positive through Reverse Transcriptase Polymerase Chain Reaction of the nasopharyngeal swab for SARS-CoV-2 between March 2020 and August 2021 in two tertiary-level hospitals.The survey included questions on demographics,work profile,characteristics of coronavirus disease 2019(COVID-19),and infection among their household or co-workers.The survey also checked the knowledge and perception of participants on the infection prevention measures related to SARS-CoV-2.RESULTS Out of a total of 346 HCWs infected with SARS-CoV-2,286(82.7%)HCWs consented to participate in this study.From the sample population,150(52.5%)of participants were female,and a majority(230,80.4%)were frontline HCWs,including 121 nurses(121,42.4%).Only 48(16.8%)participants were fully vaccinated at the time of infection.Most infected HCWs(85%)were unaware of any unprotected exposure and were symptomatic at the time of testing(225,78.7%).Nearly half of the participants(140,49%)had co-infection among household,and nearly one-third(29.5%)had coinfection among three or more household.Another 108(37.8%)participants reported crossinfection among co-workers.The frontline HCWs were significantly more infected(25.1%vs 8.6%,P<0.001)compared to non-frontline HCWs.Another significant risk factor for a high infection rate was male sex(P<0.001).Among the infected frontline HCWs,a significantly higher proportion were male and shared accommodation with family(P<0.001).COVID-19 vaccination significantly reduced the infection rate(83.2%vs 16.8,P<0.001)among HCWs.Most participants(99.3%)were aware about importance of appropriate use of personal protective equipment.However,only 70%agreed with the efficacy of the COVID-19 vaccination in preventing an infection and severe disease.CONCLUSION The risk profiling of the HCWs infected with SARS-CoV-2 found that working at frontline and being male increase the rate of infection.COVID-19 vaccination can effectively reduce the rate of transmission of SARS-CoV-2 among HCWs.

中国实现碳中和:降碳风险的识别与应对

中国实现碳中和目标必将引发能源利用模式的深度变革,重塑各领域生产生活方式既是一场系统性变革,也面临微观与宏观的转型风险。从系统视角阐释中国零碳转型过程中降碳风险及其风险的系统传导机制,并基于低碳/零碳/负碳技术创新及转化的“研发—应用—推广”的阶段过程,解析了零碳转型过程中风险因素的传导路径;指出技术成熟度、产品绿色溢价、资产沉没成本、技术应用及供应链保障五类主要降碳风险,评估其对中国碳中和目标实现和社会经济发展的影响。提出中国需从系统视角慎重把握目标实现过程中的降碳风险,从政策引领、监测核算、科技人才、创新环境、国际合作等多方面共同发力和协同推进,全局把控设计应对政策措施,应深入实施低碳技术领跑者政策、加强碳排放核算与碳减排风险评估、积极培育壮大低碳技术研发力量、营造有利于低碳创新的社会环境。

商业银行气候风险管理的国际经验与借鉴

气候变化带来的风险是当前国际国内社会关注的焦点,气候风险会通过产业链和供应链,对企业和经济产生一定程度的影响,进而在金融机构间形成风险传导。为更好地应对气候风险,国家金融监督管理总局于2023年11月发布《商业银行资本管理办法》,将气候风险纳入其他风险评估范围,从政策层面开始重视气候风险管理。为此,本文梳理国际上主要组织的气候风险管理进展及相关措施,总结其风险管理经验,并结合当前国内商业银行面临的气候风险挑战情况,从推动商业银行绿色金融发展战略、构建气候风险管理组织架构、全面了解自身气候风险分布和风险敞口、研发有效的分析工具及压力测试场景、全方位建立气候风险专业数据库等方面,提出气候风险管理措施,以健全商业银行的风险治理体系,确保有力、有序、有效地支持经济社会绿色低碳转型。

国际贸易供应链韧性评估与风险传导研究--基于重大突发事件冲击下的国际视角

重大突发事件频发使得国际贸易供应链安全问题成为各国政府关注的重要议题。全文基于全球重大卫生事件冲击下的国际视角,采用CoDEA模型分步评估供应链初始节点、子链和整体链条韧性,并利用社会网络分析法,进一步探究各节点经济体在风险传导中的角色与功能。结果表明:(1)此次疫情的冲击存在于国际贸易供应链的上游、中游与下游三个节点,对整体韧性的补偿作用有限且成本高昂;(2)风险传导与风险抵御能力不同步,在此次疫情冲击下,风险传导影响力较强的经济体通常不具备较强的供应链韧性,而中国较强的风险抵御能力对强化国际供应链网络韧性起到积极作用;(3)经济体因风险厌恶情绪,试图通过边缘化规避冲击,但并未产生实质性的避险效果;(4)相较于主受益板块与经纪人板块,此次风险传导关系以溢出板块为主,过多的外溢促使风险交叉迭代传播,加剧了疫情对国际贸易供应链的冲击损伤。基于此文章提出国际贸易供应链韧性提升与风险防范的政策启示。

面向高比例分布式能源接入的输配网两阶段风险调度研究

随着大量高比例可再生能源接入配电网,潮流呈现双向化,输电网和配电网互联性增加,分散独立的调度影响电网可靠稳定运行水平。面对输网与配网间互济需求增强的现状,提出了面向高比例分布式能源接入的输配电网两阶段风险调度研究。首先以最小运行成本为目标,构建考虑输配电网不同运行风险的日前经济调度模型,在风险限值约束情况下协同优化系统源网荷储多种可调资源;其次构建目标函数为综合风险值最小的日内风险调度模型,计算三类运行风险指标值,对日前可调控资源进行出力计划调整;最后通过改进的粒子群算例求解模型,证明了该模型可使输配电网间交互协调,协同优化运行成本与运行风险,验证了所提两阶段风险调度模型的有效性和优越性。

基于系统论事故分析模型的油气智慧管道系统信息物理风险辨识

为了辨识油气智慧管道系统中存在的信息安全风险,通过基于系统论事故分析模型(systems-theoretic accident modeling and process,STAMP)的方法,对油气智慧管道系统的信息物理安全进行全面评估与分析。首先,系统综合分析了油气智慧管道涉及的设备、设施、工艺、元件,评估其安全性。其次,通过建立STAMP模型,深入分析了各层级、元件之间的反馈信息与控制动作,形成了明确的控制反馈回路,突显了元件之间的关联与控制关系。在此基础上,系统辨识出了潜在的信息风险因素,推导并构建了可能发生的系统失效场景。以天然气输气首站油气智慧管道系统为例,研究验证了基于STAMP模型的可行性和有效性。结果显示,该方法不仅直观地描述了元件之间的关联与控制关系,而且从物理层功能安全的角度全面考虑了信息风险,特别凸显了过程控制系统(process control systems,PCS)及易受攻击的操作员站。与传统方法相比,本研究所提出的方法将信息物理安全风险因素的识别率提升至80%以上,提高了40%以上,有助于避免不必要的安全措施冗余设计,提高了安全风险管控的准确性。

面向无线网络数据安全的非对称加密传输方法

针对无线网络数据安全传输时延较长的问题,提出一种基于矩阵计算的数据开放隐私泄露评估方法。设计基于小波变换算法的无噪声数据传输通道,获取用户信息并计算网络传输数据泄露风险;依托于非对称加密技术中典型的RSA算法,设计一个密钥生成器,分别获取数据传输相关的加密秘钥、解密秘钥;基于DFT-S-OFDM模型,完成无线网络数据加密信号的高效发送与接收。实验结果表明:该方法的数据加密传输时延保持在2ms以下,平均时延约为1.02ms,数据加密传输时延降低了76.55%、88.37%。

企业社会责任存在供应链传染效应吗?——基于沪深A股上市公司的经验证据

利用沪深A股上市公司数据,考察处于供应链下游客户的社会责任表现如何影响上游供应商的社会责任履行。研究发现,社会责任表现良好的客户推动了供应商积极履行社会责任,即企业社会责任存在供应链传染效应,且主要表现在供应链责任和环境责任方面。更进一步,客户对供应商社会责任履行的促进作用具有动态效应,随着供应商与客户建立供应链关系持续的时间越长,企业社会责任的供应链传染效应越明显;当客户自愿披露社会责任报告、客户属于社会责任敏感行业或客户所在地区政府环境规制力度较大时,此时客户降低供应链风险的动机越强,企业社会责任的供应链传染效应越明显;当客户重要性水平较高、供应商产品独特性较弱或供应链关系较稳定时,此时客户降低供应链风险的能力越强,企业社会责任的供应链传染效应也越明显。研究还发现,客户驱动的供应商社会责任表现提高了供应商企业的绿色技术创新能力和企业价值。上述结果表明,客户为降低供应链风险,通过向供应商施加压力,推动了供应商积极履行社会责任。