A Critical Look into the Beuk Standard-Setting Method     

Adam E. Wyse 《Educational Measurement》2020,39(1):52-60

One commonly used compromise standard-setting method is the Beuk (1984) method. A key assumption of the Beuk method is that the emphasis given to the pass rate and the percent correct ratings should be proportional to the extent that the panelists agree on their ratings. However, whether the slope of Beuk line reflects the emphasis that panelists believe should be assigned to the pass rate and the percentage correct ratings has not be fully tested. In this article, I evaluate this critical assumption of the Beuk method by asking panelists to assign importance weights to their percentage correct and pass rate judgments. I show that in several cases that the emphasis suggested by the Beuk slope is noticeably different from what one would expect and is inconsistent with importance weight ratings. I also suggest two ways that the importance weights can be used to calculate alternate cut scores, and I show that one of the ways of calculating cut scores using the importance weights leads to larger potential differences in cut score estimates. I suggest that practitioners should consider collecting importance weights when the Beuk method is used for determining cut scores.  相似文献   

Searching high gray scale FPD scanning matrix based on PSO     

严利民  王念  田锋 《上海大学学报(英文版)》2011,15(3):207-211

With the increase of gray scale and flat panel display (FPD) size, subspace bitwise scanning strategy can be replaced traditional scanning method to cut down frame frequency. However, the direct searching strategy (DSS) becomes unfeasible to obtain corresponding high gray scale scanning matrix. Thus, particle swarm optimization (PSO) is introduced to accelerate searching for high gray scale weights scanning matrix (WSM) with its parallelism and global optimization feature. Finally a WSM of 256 gray scales is found out successfully with Matlab, which both gray linearity and scanning efficiency are satisfied.  相似文献   

Optimization of some factors affecting the performance of query expansion     

Young Mee Chung  Jae Yun Lee 《Information processing & management》2004,40(6):29

This paper examines the factors affecting the performance of global query expansion based on term co-occurrence data and suggests a way to maximize the retrieval effectiveness. Major parameters to be optimized through experiments are term similarity measure and the weighting scheme of additional terms. The evaluation of four similarity measures tested in query expansion reveal that mutual information and Yule's Y, which emphasize low frequency terms, achieve better performance than cosine and Jaccard coefficients that have the reverse tendency. In the evaluation of three weighting schemes, similarity weight performs well only with short queries, whereas fixed weights of approximately 0.5 and similarity rank weights were effective with queries of any length. Furthermore, the optimal similarity rank weight achieving the best overall performance seems to be the least affected by test collections and the number of additional terms. For the efficiency of retrieval, the number of additional terms needs not exceed 70 in our test collections, but the optimal number may vary according to the characteristics of the similarity measure employed.  相似文献   

一种改进的基于加权属性的SLOF离群点挖掘算法     

赵向兵 《雁北师范学院学报》2011,27(3)

SLOF算法采用了空间对象的空间属性和空间关系确定空间邻域,并结合非空间属性的权值来计算对象在其邻域内的离群度,但在计算属性权值时,仍然由邻域专家决定,存在人为因素。文中采用计算每个对象的每个非空间属性的去一划分信息熵增量,并通过这个值来反映各个属性对对象离群的贡献程度,给出一种改进的SLOF算法。实验结果表明,算法具有计算效率高和对用户依赖性小的优点。  相似文献   

利用平衡板测人体运动环节重量和重心位置方法的理论推导   总被引：10，自引：1，他引：9  

金季春 《北京体育大学学报》1998,(2)

人体运动环节重量和重心位置是运动生物力学定量计算与分析的基础材料,如何简便、迅速地计算出受试运动员的环节惯性参数一直是本学科中从未攻克过的难题。运用平衡板测人体重心的基本原理,通过让受试者在二维平衡板上移动四肢而改变环节重心位置,同时在不动环节上附加重量的方法推算出了人体总重心与各运动环节重心之间的关系,最终得出了各运动环节的重量与重心位置。这项研究是对人体环节重量与重心位置测量的突破性探索,具有深远的意义。  相似文献   

负重爬梯训练对大鼠腓肠肌IGF-Ⅰ、IGF-IEa、MGF和MSTN基因表达的影响   总被引：1，自引：0，他引：1  

王静  苏有存  卢健 《山东体育学院学报》2011,(5):55-58

目的:研究负重爬梯训练对大鼠腓肠肌IGF-I,IGF-I Ea,MGF和MSTN基因表达的影响。方法:12只8周龄SD雄性大鼠随机分为实验组(TG,training group)和对照组(CG,control group)。TG组采用尾部负重(负荷从体重的30%逐周增加至200%)爬梯训练模式,训练10周(3times/set,2sets/day,3days/week),采用免疫组化和RT-PCR方法分析大鼠腓肠肌IGF-I多肽、IGF-I Ea、MGF和MSTNmRNA基因表达。结果:10周训练后,相对CG组,IGF-I多肽和MGF mRNA在TG组腓肠肌的表达量上调(P<0.05),IGF-I Ea mRNA的表达量没有变化(P>0.05),MSTN mRNA的表达量下调(P<0.05)。结论:负重爬梯抗阻训练可以通过上调IGF-I多肽、MGF mRNA和下调MSTN mRNA引起大鼠腓肠肌肌肉肥大,IGF-IEa mRNA对这一过程可能没有影响。  相似文献   

一种测定金属杨氏模量的简易装置     

盛爱兰 《洛阳师范学院学报》2013,32(2):61-62

大学物理实验中,金属杨氏弹性模量的测定方法主要为光杠杆法,但该法存在调节比较困难、读数过程存在视差、成本高等不足.本文设计了一种利用激光管测定金属杨氏模量的简易装置,成本低廉且操作简单,准确度较高.  相似文献   

基于方案模糊偏好信息的一种多属性决策方法     

李甜甜  王继彬  魏翠萍 《洛阳工业高等专科学校学报》2008,18(1)

针对决策者对方案有模糊偏好信息的多属性决策问题,提出一种新的方法.通过构造优化模型,反映决策者对方案的主观偏好信息,求出属性权重向量,从而对方案进行排序.最后利用实例说明该方法的可行性.  相似文献   

On Turán type inequality with doubling weights andA * weights     

Yu Dan-sheng  Wei Bao-rong 《浙江大学学报(A卷英文版)》2005,6(7):764-768

LetH _n be the set of real algebraic polynomials of degreen, whose zeros all lie in the interval [−1,1]. The well known Turán type inequalities tell us that forf(x)∈H _n , it holds ‖f′‖≥C√n‖f‖. This note deals with the weighted Turán type inequalities with the weights having inner singularities underL ^p norm for 0<p≤∞. Our results essentially extend the result of Wang and Zhou (2002), and the method used in this paper is simpler and more direct than that of Wang and Zhou (2002). The results and methods have their own values in approximation theory and computation.  相似文献   

Nearing world-class: Singapore’s two universities in QSWUR 2015/16     

Kaycheng Soh 《Journal of Higher Education Policy & Management》2016,38(1):78-87

Many universities strive to become world-class and two of Singapore’s universities are almost there, being ranked 12th and 13th in the QSWUR 2015/16. This study looked into the details of indicator rankings and found that the two universities are comparable to those in the top 10 universities in the same ranking in practically all indicators with the exception of Citations. Further analysis of the data of the 58 highest ranking universities with complete data revealed discrepancies in the assigned and attained indicator weights. Moreover, the Academic and Citations categories were not able to be used in stepwise regression calculations. These indicate that the computed Overall result is not what the ranker intended it to be and needs re-interpretation. If rankings are not anchored in statistical ground, discussions on rankings are at the abstract and verbal level, similar to discourses on alchemy (faith) vis-a-vis chemistry (facts).  相似文献