航空公司机队集中调度理论研究

针对国内航空公司生产组织模式的特点,研究了实施航空公司机队集中调度的必要性和可行性进行,提出了"飞机-‘航班节’分配成本"的概念作为评估机队调度质量的技术经济指标,搭建起实施航空公司机队集中调度的理论框架。并通过实例进行了仿真模拟研究,结果表明:机队集中调度是航空公司运行管理模式的发展趋势,不仅必要而且可行。     

双线性对快速计算中的多项式选取

针对Miller算法的循环次数,分析了循环控制多项式的性质,得出某些类的循环控制多项式的次数的下限。在此基础上,给出适合于双线性对的椭圆曲线的相关参数的选取方法。最后,给出利用不可约分因子来生成适合于双线性对的椭圆曲线时,Miller算法的循环次数达到理论下限的充分必要条件。     

The Effects of a Stimulus-Stimulus Pairing Procedure on the Unprompted Vocalizations of a Young Child Diagnosed with Autism

The current study evaluated the effects of a stimulus-stimulus pairing procedure intended to increase spontaneous vocalizations of a young child diagnosed with autism. A multiple-baseline design across two target phonemes was used to evaluate the effects of the pairing procedure on the frequency of phonemes uttered by the participant. Data were collected during presession, postsession, and follow-up periods across three conditions: Baseline, Control, and Pairing. During the Pairing conditions, a target phoneme was repeatedly vocalized by the experimenter and was systematically paired with preferred stimuli. Results from postsession observations following the pairing condition evidenced no increase in the target sounds. Practical and theoretical implications of the results are discussed.     

Stimulus-Stimulus Pairing and Subsequent Mand Acquisition of Children with Various Levels of Verbal Repertoires

Effects of a stimulus-stimulus pairing procedure on the subsequent acquisition of mand operants were investigated. An attempt was made to shape novel sounds that emerged through the pairing procedure into a mand. Six children, aged two to five years, with moderate to severe language and communication delays, participated. Two conditions were used following the pairing condition: postpairing and direct reinforcement. The emergence of mands was compared across these conditions. An additional analysis was made of the relation between participants'' baseline verbal repertoires and the effects of the pairing and the emergence of mands. Results indicate the possibility of stimulus control from a stimulus-stimulus pairing to mand as shown in two of the participants who had demonstrated high rates of vocal play and low to no verbal repertoire prior to this study. Target vocal sounds during postpairing and direct reinforcement condition remained at zero to low levels for participants with high verbal repertoire and little vocal play, warranting future studies on relations between the pre-existing verbal repertoire and the effectiveness of stimulus-stimulus pairing.     

Using Stimulus-Stimulus Pairing and Direct Reinforcement to Teach Vocal Verbal Behavior to Young Children With Autism

In this study the effect of a stimulus-stimulus pairing procedure was used as part of a clinical investigation to increase vocalizations for two young children diagnosed with autism. This procedure involved pairing a vocal sound with a preferred stimulus (e.g., toy) to condition automatic reinforcement. In addition, this study assessed the effects of a direct reinforcement procedure to bring a vocalization under echoic control following the pairing procedure for 1 of the participants. The results showed the pairing procedure was used successfully to increase a vocalization for one of the participants, and the vocalization was brought under echoic control.     

韧性断裂裂尖过程区细观力学性态的微观物理机制

采用与原子间力的类型无关的原子间配对势来构造裂尖过程区的量子统计模型，根据材料韧性断裂过程中裂尖过程区显现热效磁效应的实验结果，研究了裂尖过程区的微观物理机制．证明材料的破坏过程绝非是一个纯粹的力学过程，热-力-电磁耦合效应不容忽视．     

An Intergenerational Journey to Remember

Abstract

With help from a grant from the Corporation for National Service, service learning was infused into four classes of a graduate gerontology course, Aging Well. Thirty-one students were paired with 31 older adults for a period of up to twenty hours. The impact on the emotional and social wellness of the older adults was assessed through student journals, electronic e-mail reflection, and the administration of a survey to older adults. Analysis indicated that the service provided to the older adults had a positive impact on their emotional and social wellness.     

Evaluating Stimulus-Stimulus Pairing and Direct Reinforcement in the Establishment of an Echoic Repertoire of Children Diagnosed with Autism

Many children with autism do not imitate adult vocalizations, an important skill in learning to talk. Pairing adult vocalizations with preferred stimuli has been shown to increase free-operant vocalizations but effects are temporary; thus, direct reinforcement may be necessary to establish durable vocal behaviors. In Experiment 1, directly reinforced echoic responses did not increase following stimulus-stimulus pairings in three children with autism. Similarly, pairings did not increase free-operant vocalizations in Experiment 2, a replication of Miguel et al. (2002). Experiment 3 demonstrated that shaping increased vowel frequency for one participant. Results suggest that variables are yet to be delineated that influence effectiveness of a stimulus-stimulus pairing procedure on vocalization frequency and acquisition of a verbal operant following such pairings.     

Assessing the Effects of Observational Conditioning and Response-Contingent Pairing on the Vocalizations of Children With Autism Spectrum Disorder

Children with autism spectrum disorder (ASD) often display impairments in communication, such as limited echoic behavior, few vocal-verbal responses, and a lack of functional communication. One potential way to foster the acquisition of vocal responses in individuals with disabilities is by conditioning vocalizations as reinforcers. Conditioning procedures include stimulus–stimulus pairing, response-contingent pairing (RCP), operant discrimination training, and observational conditioning (OC). However, previous research has not evaluated whether OC can be used to condition vocalizations as reinforcers. The current study assessed whether two conditioning procedures, RCP and OC, were effective in conditioning vocalizations as a reinforcer and also evaluated their effect on the rate of vocalizations. Participants included three children with ASD, ages 5–10 years old. During the conditioning phase, rates of vocalizations during the RCP and OC conditions and a control condition were compared within an adapted alternating-treatments design. Reinforcer assessments were completed in a multielement design, pre- and postconditioning, to assess whether the target vocalizations acquired reinforcing properties. A conditioning effect and an increase in the rate of vocalizations were observed for two of the three participants; however, the conditioning effect was minor for one participant. Overall, the results of this study indicate both the RCP and OC procedures may be beneficial in increasing vocalizations for some children and could be incorporated into clinical programs and further explored in future research.     

一种基于指纹身份的签密方案

使用了基于指纹身份的系统,提出了一种新的签密方案并对其安全性作了分析.该方案具有很好的应用前景.