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991.
对一种基于博弈论的发电厂商参与市场竞价的数学模型进行了研究。该模型以发电厂商的期望收益最大为目标,采用零和二人混合对策描述竞价问题,并假设市场电价符合正态分布。由于实际市场环境有很多不确定因素,模拟运行是评估和修正竞价策略的有效方法。采用实际机组和电力市场的数据,对几种报价方案进行了模拟,对收益和风险进行了统计分析,并对最优报价方案进行了调整。 相似文献
992.
浙江经济的快速发展引起了用电量的大幅增长,这给民营小水电的发展带来了极好的机遇.但机遇与风险并存,由于民营小电企业资金由民间出资和向民间借入,因此,存在着不同程度的财务风险,如不注意对财务风险的把握,可能使民营小水电企业面临困境.本文从分析民营小水电企业存在的财务风险入手,提出进行风险管理措施和方法,以提高民营小水电企业的生命力. 相似文献
993.
This review provides an evaluation of the correlates and/or risk factors associated with disordered eating and the pursuit of muscularity among adolescent boys. One of the main conclusions is that similar factors and processes are associated with both behavioral problems. Several factors found to be consistently associated with disordered eating among boys are also similar to those found with girls. These include body mass index, negative affect, self-esteem, perfectionism, drug use, perceived pressure to lose weight from parents and peers, and participation in sports that focus on leanness. However, as many of the findings have only been verified using cross-sectional designs, prospective studies are now needed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
994.
Although some studies suggest positive effects of treatment for sexual offenders, most studies have been hampered by the unknown influence of selective attrition (e.g., volunteers and drop-outs). In the 1980s, the Correctional Service of Canada began to require weekly community treatment sessions for all sex offenders released in the Pacific Region. This policy change provided a unique opportunity for comparing an unselected cohort of treated sex offenders (n = 403) to an untreated cohort (n = 321) released in earlier years. After an average 12-year follow-up period, no differences were observed in the rates of sexual (21.1% vs 21.8%), violent (42.9% vs. 44.5%) or general (any) recidivism (56.6% vs 60.4%) for treated and untreated groups, respectively. The outcome remained comparable after controlling for length of follow- up, year of release, age, and seven static risk factors coded from official criminal history records. Retrospective ratings of the treatment quality also showed no relationship to observed recidivism rates. The static risk factors coded in the current study accounted for considerable variance in recidivism and could easily be used to improve statistical controls in future evaluations. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
995.
This 6-year longitudinal study examined girls' peer-nominated social preference and aggression in childhood as predictors of self- and parent-reported externalizing symptoms, substance use (i.e.. cigarette, alcohol, and marijuana use), and sexual risk behavior in adolescence. Participants were 148 girls from diverse ethnic backgrounds, who were initially assessed in Grades 4-6 and again in Grades 10-12. Results supported a moderator model, indicating that social preference changed the nature of the association between childhood aggression and adolescent outcomes. When accompanied by peer rejection, aggressive behavior was moderately stable over time and significantly associated with adolescent girls' substance use and sexual risk behavior. However, under conditions of peer acceptance, no significant association between childhood aggression and adolescent outcomes emerged. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
996.
Guyll Max; Spoth Richard L.; Chao Wei; Wickrama K. A. S.; Russell Daniel 《Canadian Metallurgical Quarterly》2004,18(2):293
Four years of longitudinal data from 373 families participating in a randomized intervention-control clinical trial were used to examine whether intervention effects on adolescent alcohol and tobacco use trajectories were moderated by family risk, as defined by parental social emotional maladjustment. Consistent with earlier outcome evaluations based on analyses of covariance, analyses confirmed that both the Preparing for the Drug Free Years program and the Iowa Strengthening Families Program favorably influenced alcohol use index trajectories across the time frame of the study; only the latter program, however, evidenced positive effects on a tobacco use index. Concerning the primary research question, analyses provided no support for family risk moderation of any intervention effect. Findings indicate the feasibility of developing universal preventive interventions that offer comparable benefits to all families. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
997.
This study used cluster analysis to identify three patterns of sexual health risk behaviors in a sample of adult rape survivors (N=102). Women in the 1st cluster (high risk) reported substantial increases from pre- to postrape in their frequency of sexual activity, number of sexual partners, infrequency of condom use, and frequency of using alcohol and/or drugs during sex. The 2nd cluster (moderate risk) reported increases in frequency of sexual activity and number of partners but mitigated that risk with increased condom use. Survivors in the 3rd cluster (low risk) indicated that their sexual health behaviors had become much less risky postrape. An ecological model predicting cluster membership revealed that individual-level and contextual factors predict patterns of risk behaviors. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
998.
Eiden Rina D.; Leonard Kenneth E.; Hoyle Rick H.; Chavez Felipa 《Canadian Metallurgical Quarterly》2004,18(4):350
This study examined the transactional nature of parent-infant interactions over time among alcoholic and nonalcoholic families. The sample consisted of 222 families assessed at 12, 18, and 24 months of child age. Results indicated that infant behavior did not influence parental behavior across time, but parental behavior was longitudinally predictive of infant behavior during play interactions. Higher paternal alcohol consumption at 12 months was longitudinally predictive of negative parental behavior at 24 months. Other significant risk factors included marital conflict, fathers' depression, and fathers' education. Results highlight the nested nature of risk in alcoholic families and the direction of influence from parent to child during interactions and suggest that 1 pathway to risk among these children is through negative parent-infant interactions. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
999.
Relapse is a central problem in smoking treatment. Data collected at the time of relapse episodes indicate that stress and negative affect (NA) promote relapse, but retrospective data are potentially biased. The authors performed a prospective analysis of stress and NA prior to initial lapses in smokers (N = 215). Day-to-day changes in stress (daily negative and positive events and Perceived Stress Scale scores) and NA (multiple momentary affect ratings) did not predict lapse risk on the following day. However, within the lapse day itself, NA was already significantly increasing hours before lapses, but only for episodes attributed to stress or bad mood. Thus, rapid increases in NA, but not slow-changing shifts in stress and NA, were associated with relapse. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
1000.
Joiner Thomas E. Jr.; Pettit Jeremy W.; Rudd M. David 《Canadian Metallurgical Quarterly》2004,35(1):84
The authors' purpose is to provide some empirical perspective on the important but understudied possibility that when people become more energetic in the context of continued depressive symptoms, suicide risk escalates. The authors studied 109 suicidal young adults; among those who initially reported substantial depression, a subgroup was identified whose energy was increasing in context of continued depressive symptoms. They were compared with others with regard to suicidality 1 month later. Results suggested that those who have incomplete remissions (of any sort) may be more ill to begin with, and this may account for higher suicide risk. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献