静态和动态相结合的病毒检测方法研究

传统的计算机病毒检测方法主要有长度检测法、病毒签名检测法、特征代码检测法、校验法、行为监测法等。这些方法依据的原理不同，大体上分为病毒静态检测和动态检测两类，这两类计算机病毒的动态检测与静态检测各有其优缺点。但随着计算机病毒技术的不断更新，使传统的病毒检测技术已经无法有效地检测已知病毒的变种或未知病毒，由此笔者想到能否将二者结合起来，扬长避短，以实现病毒的高效检测。本文引入Dempster—Shafer证据理论用于融合病毒动态检测器和静态检测器的结果，实现计算机病毒的自动检测。     

项目教学在《饲料分析与检测》中的应用

针对“项目教学”法、高职院校学生和《饲料分析与检测》课程的特点，提出了“项目教学”在《饲料分析与检测》课程中的应用方法及注意事项。     

氟喹诺酮药物残留的检测方法研究进展

氟喹诺酮是一种人工合成的广谱抗生素,在防治动物及人类的感染性疾病中具有重要应用。由于抗生素药物的不合理使用,导致在动物源性食品中残留超标,长期食用将严重危害人体健康,因此,对于动物源性食品中氟喹诺酮残留检测具有重要的意义。有关氟喹诺酮残留的检测方法大致可分为微生物法、免疫法、色谱法和光谱法等。     

固体废弃物毒性浸出液重金属的检测

生活垃圾焚烧飞灰等固体废弃物中由于含有大量重金属等污染物而被列为危险废物,药剂稳定化填埋是其处置的最佳途径,无害化后毒性浸出液中重金属含量应满足GB 16889-2008的限值。由于浸出液成分复杂,而重金属铅的限值浓度仅为0.25mg/L.检测方法的选择至关重要。本文对现行国标规定的以铅为代表的重金属检测方法进行了系统总结及对比,指出各种方法在检测时存在的问题,优先推荐采用ICP-MS法对浸出液进行检测。     

基于瞬时无功功率理论的电流高次谐波检测方法研究

介绍了基于瞬时无功功率理论的谐波检测方法原理,通过对基于瞬时无功功率理论的ip-iq检测方法在电流谐波检测应用中的分析研究,在ip-iq检测方法的基础上,提出了一种适于电流高次谐波检测的改进ip-iq检测方法.这种方法通过在原检测方法中补加上负序分量检测环节,可检测出电流高次谐波的正序和负序分量,进而实现电流高次谐波的检测.最后,通过仿真实验表明了改进的方法对电流高次谐波的检测比原方法具有更好的准确性,更适于对具体的高次谐波进行检测.     

小议汉译英中的词语省译

汉译英时可以采用多种方法将汉语翻译成英语,如音译法、直译法、意译法、增补法、减词法、转换词性的方法等等,应根据不同的情况灵活运用各种翻译方法,以达到准确翻译的目标。本文对汉译英中的省译方法进行了分析,并举例说明。     

案例教学法在汽车检测技术教学中的应用

<正>汽车检测技术是一门实践性较强的课程,涉及汽车检测设备的原理、构造、使用方法;汽车检测程序、方法;汽车故障诊断与排除等内容。汽车使用性能的下降、故障的产生,影响因素是多方面的,如按部就班地采用传统的     

构造法的数学思想及其运用

构造的思想方法是解决数学问题常用的思想方法。本文介绍了方程构造法、命题构造法、模型同类构造、解图形构造、函数构造等构造法的运用。     

《汽车检测与故障诊断技术》课程教学方法改革探索

汽车检测与故障诊断技术是汽车检测维修技术专业的主干课程,是汽车检测与维修技术专业群针对于汽车维修工岗位能力进行培养的一门核心课程.主要包括汽车总成、零部件的结构、工作原理,汽车拆装工具的使用方法、各主要总成的拆装顺序及调整调试方法,汽车故障诊断、检测、维修以及必备的技术服务.该课程在汽车专业人才培养方案中具有重要的地位,是专业技能培养的核心环节.     

电阻常用测量方法的分析及应用

测量电阻的方法较多,分类方法也较多。如按所使用的仪表,常用电阻测量方法可分为伏安法、直流单臂电桥法、直流双臂电桥法和利用万用表测电阻等。     

A comparative assessment of track plates to quantify fine scale variations in the relative abundance of Norway rats in urban slums

Norway rats (Rattus norvegicus) living in urban environments are a critical public health and economic problem, particularly in urban slums where residents are at a higher risk for rat borne diseases, yet convenient methods to quantitatively assess population sizes are lacking. We evaluated track plates as a method to determine rat distribution and relative abundance in a complex urban slum environment by correlating the presence and intensity of rat-specific marks on track plates with findings from rat infestation surveys and trapping of rats to population exhaustion. To integrate the zero-inflated track plate data we developed a two-component mixture model with one binary and one censored continuous component. Track plate mark-intensity was highly correlated with signs of rodent infestation (all coefficients between 0.61 and 0.79 and all p-values?<?0.05). Moreover, the mean level of pre-trapping rat-mark intensity on plates was significantly associated with the number of rats captured subsequently (Odds ratio1.38; 95 % CI 1.19–1.61) and declined significantly following trapping (Odds ratio 0.86; 95 % CI 0.78–0.95). Track plates provided robust proxy measurements of rat abundance and distribution and detected rat presence even when populations appeared ‘trapped out’. Tracking plates are relatively easy and inexpensive methods that can be used to intensively sample settings such as urban slums, where traditional trapping or mark-recapture studies are impossible to implement, and therefore the results can inform and assess the impact of targeted urban rodent control campaigns.     

孔板流量计在设计应用中的若干问题

介绍吴厂出厂气用孔板流量计概况及其准确度下降的原因与对策。     

影响煤气孔板流量计精确度的因素及对策

结合孔板流量计的实际使用情况,探讨了如煤气密度(组分)变化、煤气含水量、煤气中的杂质、二次仪表的误差等这些造成孔板流量计精确度下降的主要因素,并提出了诸如修正密度、处理水和水蒸气、定期清洗、吹扫计量装置、定期校验二次仪表等改进措施。     

A COMMON PROPERTY EXPERIMENT WITH A RENEWABLE RESOURCE

This series of three classroom experiments demonstrates the tragedy of the commons and suggests two possible solutions: communication and individual property rights. In the first and second experiments, students jointly own a renewable resource in the form of a plate of M&Ms. Communication is not allowed in the first experiment, whereas in the second experiment students may try to influence each other's desired harvest. The third experiment divides the plate to establish individual property rights.     

An evaluation of the nutrition education and training program : Findings from Nebraska

This paper summarizes methods and findings from a classical randomized experiment used to evaluate the Nutrition Education and Training (NET) Program that was developed and implemented in Nebraska. The evaluation focused on assessing how well the program was implemented and the impact it had on children's nutrition-related knowledge, attitudes, preferences, and habits. Data were collected from over 2,300 children in 96 classrooms distributed across grades 1–6 in 20 schools spanning the state of Nebraska. The 20 participating schools were selected from 98 volunteers and were assigned to treatment or control status using a modified random assignment procedure that resulted in equivalent pretest means on outcome measures. Pretest data and two waves of posttest data were collected. The evaluation found strong positive effects in all grades on several measures of nutrition knowledge, positive effects on reported food preference and willingness to select new foods in the school lunch line in grades 1–3, positive effects on willingness to taste previously rejected foods in grades 4–6, and no consistent effects on food attitudes, reported food habits, or plate waste.     

A BANDWAGON EFFECT IN PERSONALIZED LICENSE PLATES?

The bandwagon effect is a consumption externality that exists when an individual's demand for a good is increased by his observation of other consumers using that good. This paper models a product demand curve with a bandwagon effect and, using data on sales of personalized license plates, estimates such a demand curve. Certain more conventional models of product demand, including information diffusion and habit formation models, are observationally similar to the bandwagon model, despite being conceptually different from it. I attempt to use the license plate data to discriminate between the bandwagon model and these other models.     

BATTER UP! MORAL HAZARD AND THE EFFECTS OF THE DESIGNATED HITTER RULE ON HIT BATSMEN

American League batters have been hit by pitches 10% to 15% more frequently than National League batters since the designated hitter rule was introduced in 1973. This evidence is consistent with the idea that the American League s adoption of the designated hitter rule created a classic moral hazard problem. Because they are not required to appear at the plate, American League pitchers can throw at opposing hitters with greater impunity (i.e., at lower cost) than National League pitchers who must take their turns at bat and, hence, bear more of the costs of their own actions. (JEL D81, J28)     

The problems and prospects in the teaching of mixed methods research

There are pedagogical challenges USA students and instructors face within mixed methods classrooms. Instructors of mixed methods are often self-taught, lacking adequate training in both qualitative and quantitative approaches to research. Students are not often trained in both research approaches. These dual training gaps can result in deep pedagogical issues compromising students’ ability to fully understand mixed methods research praxis and leaving teachers feeling ill equipped to address students’ learning concerns. To tackle the myriad of challenges confronted in the mixed methods classroom requires structural changes to the current way graduate training programs in social research methods are organized and taught. Developing a team-based teaching approach to mixed methods research that provides students with instructors who have the requisite qualitative and quantitative knowledge can serve as a pedagogical model that can begin at least to address the current methods and methodological skills gap in the teaching of mixed methods research.     

Examining mixing methods in an evaluation of a smoking cessation program

Three different methods were used in an evaluation of a smoking cessation study: surveys, focus groups, and phenomenological interviews. The results of each method were analyzed separately and then combined using both a pragmatic and dialectic stance to examine the effects of different approaches to mixing methods. Results show that the further apart the methods are philosophically, the more diverse the findings. Comparisons of decision maker opinions and costs of the different methods are provided along with recommendations for evaluators’ uses of different methods.     

The psychological measurement of childhood sexual development in Western societies: methodological challenges

Children can display sexual behavior or have sexual experiences. Different psychological research methods are available for studying these kinds of behaviors and feelings, such as interviewing or observing children (direct methods), asking adolescents or adults to retrospectively report their childhood memories or using intermediaries to observe children (indirect methods). Each of these methods has its own advantages and limitations. Based on a review of the literature, this work answers three questions: (a) What research methods are generally used to study childhood sexual development? (b) What insight do these methods give into the sexual behaviors or feelings of children? and (c) What are the advantages and limitations of each of these research methods in this research domain? Almost all studies on childhood sexual behavior and feelings use either observational or retrospective methods. In both types of studies, only behavior that is considered to be sexual from an adult perspective is reported. To gain insight into the child's perspective, one has to rely on methods other than observations or retrospective research, such as interviews with children that match their developmental limitations and competencies.