Bayes discriminant analysis method to identify risky of complicated goaf in mines and its application

A Bayes discriminant analysis method to identify the risky of complicated goaf in mines was presented. Nine factors influencing the stability of goaf risky, including uniaxial compressive strength of rock, elastic modulus of rock, rock quality designation （RQD）, area ratio of pillar, ratio of width to height of pillar, depth of ore body, volume of goaf, dip of ore body and area of goal, were selected as discriminant indexes in the stability analysis of goal. The actual data of 40 goals were used as training samples to establish a discriminant analysis model to identify the stability of goaf. The results show that this discriminant analysis model has high precision and misdiscriminant ratio is 0.025 in re-substitution process. The instability identification of a metal mine was distinguished by using this model and the identification result is identical with that of practical situation.

Relationship between Migration and HIV Risky Behavior: a Comparative Study of Returning Migrants and Non Migrants Based on Rural Out-of-school Youth in Jilin, China

Objective To estimate the relationship between migration and HIV risky behavior when controlling for gender, age, and educational levels and to evaluate the gender differences in migration, HIV knowledge, and HIV risky behaviors among rural youth in China. Methods A cross-sectional, anonymous, investigative questionnaire for 1710 unmarried, out-of-school rural youth, aged between 15 and 24 years, was handed out in Gongzhuling county of Jilin province, China. Results 58.5% of participants had a history of migration, irrespective of gender. There were gender differences observed in other factors such as drug abuse（4.3% for males and 5.5% for females, P〈0.01）, multiple sexual partners（24.1% for males and 44.1% for females, P〈0.01）, and HIV knowledge rate（35.2% for males and 25.5% for females, P〈0.001）. While controlling for gender, age, and educational levels, the relationships between migration and drug abuse, selling sex, and non usage of condoms during last instance of sexual activity were found to be significant. The cases of premarital sex and multiple sexual partners were both not found to be related to migration. Conclusion Among rural youth, the HIV risky behavior such as drug abuse, selling sex, and lack of condom use, is significantly related to migration, while premarital sex and multiple sexual partners seem unrelated to migration.

Health-related risky behaviors and their risk factors in adolescents with high-functioning autism

BACKGROUND Health-related risky behaviors generally refer to behaviors that have a negative impact on health and quality of life.Health-related risky behaviors in adolescents with high-functioning autism(HFA)have not been well understood so far.Adolescents with HFA may have more health-related risky behaviors than neurotypical adolescents.AIM To investigate health-related risky behaviors and their risk factors with HFA.METHODS This is an observational study.Our study enrolled 110 adolescents aged 12-19-years-old meeting Diagnostic and Statistical Manual of Mental Disorders 4th edition criteria for HFA.They were recruited from Peking University Sixth Hospital.There were also 110 age,sex and nationality matched controls enrolled who came from a public school in Beijing,China.Both groups completed the Adolescents Health-related Risky Behavior Inventory.Nonparametric tests were carried out for comparison of the Adolescents Health-related Risky Behavior Inventory scores between the two groups.Expression recognition,the Inventory of Subjective Life Quality for Child and Adolescent,Chinese Wechsler Intelligence Scale for Children,Wechsler Intelligence Scale for Adult-Chinese Revised,Theory of Mind test and Autism Spectrum Screening Questionnaire were assessed in the autism group to explore factors associated with health-related risky behaviors.Multivariate regression analysis was conducted to explore the risk factors of health-related risky behaviors in the HFA group.RESULTS The results showed that the total score of the Adolescents Health-related Risky Behavior Inventory and scores of“aggression and violence,”“suicide and selfinjury,”“health compromising behavior”and“unprotected sex”subscales in the HFA group were significantly higher than those in the control group(Z range-4.197 to-2.213,P<0.05).Among the associated factors,poor emotional experience(B=-0.268,P<0.001),depression(B=-0.321,P<0.001),low score of intelligence(B=-0.032,P=0.042),low score of Theory of Mind test(B=-1.321,P=0.003)and poor adaptation to school life(B=-0.152,P=0.006)were risk factors.These risky behaviors may promote the occurrence of health-related risky behaviors in adolescents with HFA.CONCLUSION This study showed that adolescents with HFA were more likely to be involved in health-related risky behaviors.Different health-related risky behaviors have different reasons.

Portfolio optimization of credit risky bonds: a semi-Markov process approach

This article presents a semi-Markov process based approach to optimally select a portfolio consisting of credit risky bonds.The criteria to optimize the credit portfolio is based on l_(∞)-norm risk measure and the proposed optimization model is formulated as a linear programming problem.The input parameters to the optimization model are rate of returns of bonds which are obtained using credit ratings assuming that credit ratings of bonds follow a semi-Markov process.Modeling credit ratings by semi-Markov processes has several advantages over Markov chain models,i.e.,it addresses the ageing effect present in the credit rating dynamics.The transition probability matrices generated by semi-Markov process and initial credit ratings are used to generate rate of returns of bonds.The empirical performance of the proposed model is analyzed using the real data.Further,comparison of the proposed approach with the Markov chain approach is performed by obtaining the efficient frontiers for the two models.

Risky Meetings Despite Knowledge of the Risk: A Qualitative Study of Young Adults Treated for Chlamydia Infection at a Sexual Transmitted Infection Clinic

The aim of the study was to describe the attitudes to risk behavior among patients diagnosed with a Chlamydia infection at a Sexual Transmitted Infection (STI) clinic. Qualitative interviews face-to-face were conducted with twenty patients, aged 18 - 30 years, with confirmed Chlamydia infections were included. An interview guide was used and the participants described the behavior that had led to the infection. The material was analyzed using qualitative content analysis. Eighteen informants were included and the theme was risk. Recurrent among the informants was risk behavior in sexual relations when using alcohol, while risk behavior in life in general was almost non-existent. Of the 18 informants, sixteen had previously been tested for STIs, and ten had had an STI before. Alcohol consumption emerged as a common denominator among the informants and as a contributor to risk. In contrast, almost none of the informants exposed themselves to any unnecessary risks in life in general.

Internet Usage and Household Investment on Risky Financial Assets

Using panel data from the China Family Panel Studies for 2010,2014 and 2016,this paper uses a two-part model,with the first part using a fixed-effects panel logit model and the second part using a linear logit fixed-effects model to study the impact of Internet usage on Chinese households’participation in risky financial markets and the intensity of investment in risky assets after participation.The results find that Internet usage can promote household participation in the risky finance market and increase household investment in risky assets.Therefore,accelerating Internet usage can promote Chinese households’participation in the risk finance market.

Childhood Adversity Phenotypes and Risky Health Behaviors among Chinese Adolescents: Extending the Concept of Adversity

ObjectiveTo present an approach to phenotyping ACEs and explore the association between ACEs and adolescent health risky behaviors based on the social context of China.Methods Totally,5,726 adolescents aged 12-18 years were investigated about their ACEs in the family,peer,school,and personal domains and the occurrence of six types of risky health behaviors(i.e.,smoking,drinking,sexual intercourse,self-harm,and suicidal ideation and attempts).Latent class analysis(LCA)was used to explore the ACE patterns.Results Six latent classes of ACEs were identified,including low adversity,school adversity,school adversity and peer victimization,peer victimization,maltreatment and peer victimization,and high adversity,and associated with risky health behaviors in adolescents.Being physically punished by a teacher,experiencing sexual abuse,and experiencing family trauma most strongly differentiated from the six AcE classes and were correlated with an increased risk for risky adolescent health behaviors.ConclusionThis study supports a positive association between ACEs and risky adolescent health behaviors.Peer victimization,school adversity and associated contexts need to be considered in future ACEstudies.

Asymptotics of discounted aggregate claims for renewal risk model with risky investment

Under the assumption that the claim size is subexponentially distributed and the insurance surplus is totally invested in risky asset, a simple asymptotic relation of tail probability of discounted aggregate claims for renewal risk model within finite horizon is obtained. The result extends the corresponding conclusions of related references.

Internal Transactions for Multiple Risky Assets

Most of the articles about insider trading assume that there is only one risky asset in the market. On the basis of these papers, this thesis is mainly divided into three parts to study the situation of multiple risky assets in the market. In the first part, the situation of multiple risky assets in the market when two transactions are in progress is studied and then, the equilibrium when the market requires the internal traders to disclose the trading volume after each transaction is analyzed. In the second part, the equilibrium of multi-period based on the two phases of transaction is derived. The third part is the summary of the paper.

Peer Pressure Is the Prime Driver of Risky Sexual Behaviors among School Adolescents in Addis Ababa, Ethiopia

Background: Understanding ecological factors that influence risky sexual behavior of adolescents is vital in designing and implementing sexual risk reduction interventions in specific contexts. Interventions undertaken without understanding the critical factors may not produce the desired results. Objective: The objective of this study was to identify the factors associated with adolescent risky sexual behavior among school adolescents in Addis Ababa, Ethiopia. Methods: This cross-sectional study was done among randomly selected school adolescents in Addis Ababa, Ethiopia. Data were collected by an anonymous self administered questionnaire. Risky sexual behavior was assessed by asking question about sexual activity, consistent condom use and faithfulness to a single partner. Logistic regression analysis was done to identify factors related to sexual behavior using the ecological framework. Result: Overall 377(10.6%) of the 723 sexually active students were involved in risky sexual practices. Risky sexual behavior was significantly and very strongly associated with perception of peers' involvement in sexual intercourse [AOR = 11.68 (95% CI: 8.76 - 15.58)]. Conclusion: This study demonstrated that peer pressure is the most important factor associated with risky sexual behavior among school adolescents in Addis Ababa. Interventions aimed at reducing sexual behavior among school adolescents should target adolescents as a group rather than individually.

Risky Sexual Behaviour among Big Construction Enterprise Workers;Bahir Dar City, Amhara Regional State, Northwest Ethiopia

Background: Risky sexual behaviors are the major factors in rising sexually transmitted infections among adolescents and young adults. In Ethiopia construction industry is on increasing and deriving young people from rural area to the cities. Therefore, the aim of this study was to determine the prevalence of risky sexual behaviour and factors associated with among construction workers. Methods: A cross sectional study was conducted in March 2012 among construction workers in Bahir Dar city. The analysis was carried out using SPSS version 16. The data were analyzed in bivariate and multivariate logistic regression. Result: The prevalence of risky sexual behavior among construction workers was 44.9%. Female workers were about four times more likely to have had risky sexual practices than males (AOR = 3.86, 95% CI: 2.34 - 6.37). Respondents whose educational level less than fourth grade were 12 times more likely to be engaged in risky sex than whose educational level tenth grade or more (AOR = 12.13, 95% CI: 1.84 - 79.78). Divorced individuals were about five times more likely to have had risky sexual activities than married individuals (AOR = 4.63, 95% CI: 1.32 - 16.12). Respondents whose first sexual commencement from 15 - 19 years were about three times more likely to have had risky sexual behavior than from 20 - 24 years (AOR = 2.89, 95% CI: 1.70 - 4.91). Besides, the odds of having risky sexual behaviour among construction workers who had sexual partner at the time of the study were about 0.6 times less likely to have had risky sexual behaviours than workers who did not have (AOR = 0.6, 95% CI: 0.38, 0.96). Conclusion: The prevalence of risky sexual behavior among construction workers was 44.9%. Variables such as sex, educational level, marital status, age at first sexual intercourse, presence of current sexual partner and casual sex were found to be independent predictors of risky sexual behaviour. Therefore, interventions targeting on these factors were recommended.

Risky Sexual Behavior and Its Determinants among Orphan and Vulnerable Children in Addis Ababa, Ethiopia

Back Ground: Risky sexual behavior among orphans and vulnerable children and its associated physical, psychological and social consequences is becoming a major public health concern globally. Objectives: To assess the prevalence of risky sexual behavior and its determinants among orphan and vulnerable children in Addis Ababa. Methodology: A community based cross sectional study was conducted on three support and care giving organizations for orphans and vulnerable children in Addis Ababa, Ethiopia from March to June 2014. A total of 422 orphan and vulnerable children were selected using systematic sampling. Data were collected using pre tested self-administered questionnaire. Logistic regression was used to analyze the data. Result: A total of 407 (96.4%) respondents participated in this study. Among them 112 (27.5%) had sexual intercourse in their life time, of these 50 (44.6%) started sex before the age of 15, 94 (83.9%) had forced sex, 84 (75.0%) had multiple sexual partners, only 16 (14.3%) used condom the first time they had sex and 96 (85.7%) participated in transactional sex. Females were about 3.25 (2.67 - 7.3) times more likely to engage in risky sexual behavior than male respondents, double orphans had 4.32 (2.45 - 9.54) odds of risky sexual behavior compared to their counterparts. Those respondents who had knowledge of HIV transmission and prevention were less likely to be involved in risky sexual behavior 0.58 (0.41 - 0.93). Conclusion: Orphan and vulnerable children are at a higher likelihood of risky sexual behavior. Intervention targeted at multilevel such as orphan survival training, assertive communication skills, sexuality education and education about HIV risk perception, physical, psychological and human right protection, social support, and economic access for basic needs need to be given consideration.

Prevalence and Factors Associated with Risky Sexual Behaviors among Patients with Severe Mental Illness in Uganda: A Descriptive Cross Sectional Study

Background: Persons living with severe mental illness (SMI) which includes schizophrenia, bipolar affective disorder and recurrent major depressive disorder are predisposed to risky sexual behavior (RSB). There is a paucity of data on this problem in sub-Saharan Africa and where research has been undertaken, only a limited range of risk factors have been considered and most of it was undertaken before antiretroviral therapy was universally available, hence the need for this study. The objective of this study was to determine the prevalence and factors associated with risky sexual behavior among individuals with SMI attending care in central and south western Uganda. Methods: A cross sectional study was conducted among 393 persons with SMI attending two psychiatric out-patient facilities in Uganda. Psychiatric disorder was confirmed using MINI International Neuropsychiatric Interview version 7.2. RSB was defined as engaging in at least one of four risky sexual behaviours that have been associated with HIV infection in the Ugandan psychosocial environment in the last three months using an 8 item RSB questionnaire used for assessment of RSB. Prevalence of RSB and associated correlates were determined using multiple logistic regression. Results: The Prevalence of RSB in last 3 months’ periods was 24.2% (95% CI: 20.2% - 28.7%). The factors that were independently significantly associated with RSB were: trauma related (history of childhood trauma, past and current sexual abuse, past and current physical abuse) current psychosocial challenges (mental health stigma) and psychiatric illness factors (history of a past manic episode, current psychotic episode, severity of depressive symptoms and severity of manic symptoms). Conclusions: One quarter of clinic attending respondents with severe mental illness in Uganda practice risky sexual behaviour. Factors associated with risky sexual behaviour fall under the domains of past and present trauma, current psychosocial challenges and psychiatric illness factors. This calls for a multi-sectoral approach that includes community awareness about the nature of SMI and the rights of persons with SMI and measures to improve Psychiatric symptom management.

Investigation on the Deformation of Functional Elements of Risky Technical Systems

This paper examines the mutual displacement of functional elements （FE） of risky technical systems （RTS）. To this group of systems belong transport systems, technical systems operating in heavy regimes, energy and power systems, building structures. etc. A unit of mutual displacement of the functional elements of RTS is introduced, as well as a definition of the deformator of the system. The value of the deformator of a sample system is determined.

Approach Evaluating an Investment Project under Uncertainty by Risky Index of Time

The effectiveness of evaluating an investment project based on predicting cash flows depends on the uncertainty of its future cash flows. The remoter the cash flows are, the higher the uncertainty is. Because of this, this paper suggests to discount cash flows by applying risky index of time （RIT）. Thus, the discount rate used to discount the distant cash flows is higher that the discount rate used to discount the near cash flows. By this systematic method, the risk caused by the uncertainty of future cash flows can be hedged in making investment decision. To a certain degree, this approach is reasonable in evaluating investment alternatives under uncertainty. Furthermore, the paper puts forward a practical approach on determining RIT in practice.

Association of risky driving behavior with psychiatric disorders among Iranian drivers:A case-control study

Purpose:This study aimed to investigate the possible association between psychological disorders and riskydriving behavior(RDB)in Iran.Methods:This case-control study conducted in Shiraz,Iran in 2021.The case group included drivers with psychological disorders and the control group included those without any disorders.The inclusion criteria for selecting patients were:active driving at the time of the study,being 18-65 years old,having a driving license,having a psychological disorder including depression,bipolar disorder,anxiety spectrum disorder,or psychotic disorder spectrum confirmed by a psychiatrist,and completing an informed consent form.The exclusion criterion was the existence of conditions that interfered with answering and understanding the questions.The inclusion criteria for selecting the healthy cases were:active driving at the time of the study,being 18-65 years old,having a driving license,lack of any past or present history of psychiatric problems,and completing an informed consent form.The data were gathered using a researcher-made checklist and Manchester driving behavior questionnaire.First,partition around medoids method was used to extract clusters of RDB.Then,backward logistic regression was applied to investigate the association between the independent variables and the clusters of RDB.Results:The sample comprised of 344(153 with psychological disorder and 191 without confirmed psychological disorder)drivers.Backward elimination logistic regression on total data revealed that share of medical expenditure≤10%of total household expenditure(OR=3.27,95%Cl:1.48-7.24),psychological disorder(OR=3.08,95%Cl:1.67-5.70),and substance abuse class(OR=6.38,95%CI:3.55-11.48)wereassociatedwithhighlevelof RDB.Conclusion:Substance abuse,psychological illnesses,and share of medical costs from total household expenditure were found to be main predictors of RDB.Further investigations are necessary to explain the impact of different psychological illnesses on driving behavior.

Ruin probability of the renewal model with risky investment and large claims

The ruin probability of the renewal risk model with investment strategy for a capital market index is investigated in this paper.For claim sizes with common distribution of extended regular variation,we study the asymptotic behaviour of the ruin probability.As a corollary,we establish a simple asymptotic formula for the ruin probability for the case of Pareto-like claims.

Challenges of human-machine collaboration in risky decision-making

The purpose of this paper is to delineate the research challenges of human-machine collaboration in risky decision-making.Technological advances in machine intelligence have enabled a growing number of applications in human-machine collaborative decisionmaking.Therefore,it is desirable to achieve superior performance by folly leveraging human and machine capabilities.In risky decision-making,a human decisionmaker is vulnerable to cognitive biases when judging the possible outcomes of a risky event,whereas a machine decision-maker cannot handle new and dynamic contexts with incomplete information well.We first summarize features of risky decision-making and possible biases of human decision-makers therein.Then,we argue the necessity and urgency of advancing human-machine collaboration in risky decision-making.Afterward,we review the literature on human-machine collaboration in a general decision context,from the perspectives of human-machine organization,relationship,and collaboration.Lastly,we propose challenges of enhancing human-machine communication and teamwork in risky decisionmaking,followed by future research avenues.

Optimal Investment with Multiple Risky Assets for an Insurer with Modified Periodic Risk Process

This paper considers the optimal investment problem for an insurer in the sense of maximizing the adjustment coefficient of the risk process.The authors propose a modified periodic risk model in which the periodic risk process is perturbed by a standard Brownian motion.The insurer can invest in multiple risky assets and one risk-free asset and the correlations between the risky assets and the risk process are considered.Optimal strategy is obtained explicitly,which is a function of time and related to the risk process.The effects of market parameters on the optimal strategy are discussed and a numerical example is also given.