Multi-Objective Artificial Bee Colony Algorithm for Parameter-Free Neighborhood-Based Clustering

Although various clustering algorithms have been proposed, most of them cannot handle arbitrarily shaped clusters with varying density and depend on the user-defined parameters which are hard to set. In this paper, to address these issues, the authors propose an automatic neighborhood-based clustering approach using an extended multi-objective artificial bee colony (NBC-MOABC) algorithm. In this approach, the ABC algorithm is used as a parameter tuning tool for the NBC algorithm. NBC-MOABC is parameter-free and uses a density-based solution encoding scheme. Furthermore, solution search equations of the standard ABC are modified in NBC-MOABC, and a mutation operator is used to better explore the search space. For evaluation, two objectives, based on density concepts, have been defined to replace the conventional validity indices, which may fail in the case of arbitrarily shaped clusters. Experimental results demonstrate the superiority of the proposed approach over seven clustering methods.

Validitas dan Realibilitas Instrumen Teori Pilihan Karir Holland di Indonesia

Validity and reliability are the main topics in every research instruments. It is important how to create research instrument that is connected to the construct being measured. In this article, the authors tested the validity and reliability of Holland's career instrument Indonesian version. The participants involved are in the period of career preparation and choice, within an educational institution or a job, but has not yet had satisfaction with their career. The participants' age range from 15 to 27 years. The validity test is carried out using the conventional validity type, where the item is declared valid if the correlation coefficient is ≥ 0.3. The results showed 43 items were declared valid and 5 items were declared invalid while the reliability coefficient found is 0.906. Based on the results, Holland's career instrument Indonesian version in a good instrument to measure career preparation and career choice.

A Comparative Analysis: Heuristic Self-Search Inquiry as Self-Knowledge and Knowledge of Society

In research, the standard view of credibility seeks to illuminate what the researcher did with the data vis-à-vis collection, analysis, and interpretation. This works well in standard research where data can be checked through conventional validity measures (internal validity, external validity, reliability, replicability, and objectivity). It does not work well in heuristic self-search inquiry (HSSI) method where the data are in the researcher. In previous HSSI works, there is a level of uncertainty regarding the use of the method in knowledge exploration. It seems that there is still a need for the development of methodological understanding, particularly in terms of those who favor the use of multiple participants in HSSI, as opposed to those who do not. In this article, I compared four studies to clarify HSSI’s utility in knowledge production for future use.

The Umbrella That Is Too Wide and Yet Too Small: Why Dynamic Testing Has Still Not Delivered on the Promise That Was Never Made

In this article, I reflect on potential reasons for the seemingly persistent impression that dynamic testing has not delivered on its promise. Potential reasons are embedded in a paradox. On the one hand, validity-related expectations toward dynamic tests seem too broad. This includes fuzziness in defining the diagnostic target constructs, simplistic quantitative focus on conventional validity indices, and overgeneralized expectations regarding incremental validity. At the same time, the focus on dynamic testing seems too narrow. By introducing three tests of cognitive flexibility, I exemplify that dynamic testing has potential which goes beyond the assessment of learning potential in specific subpopulations. My ambition is to help in addressing potential users’ misconceptions about dynamic testing productively.

Fast FCM with Spatial Neighborhood Information for Brain Mr Image Segmentation

Among different segmentation approaches Fuzzy c-Means clustering (FCM) is a welldeveloped algorithm for medical image segmentation. In emergency medical applications quick convergence of FCM is necessary. On the other hand spatial information is seldom exploited in standard FCM; therefore nuisance factors can simply affect it and cause misclassification. This paper aims to introduce a Fast FCM (FFCM) technique by incorporation of spatial neighborhood information which is exploited by a linear function on fuzzy membership. Applying proposed spatial Fast FCM (sFFCM), elapsed time is decreased and neighborhood spatial information is exploited in FFCM. Moreover, iteration numbers by proposed FFCM/sFFCM techniques are decreased efficiently. The FCM/FFCM techniques are examined on both simulated and real MR images. Furthermore, to considerably decrease of convergence time and iterations number, cluster centroids are initialized by an algorithm. Accuracy of the new approach is same as standard FCM. The quantitative assessments of presented FCM/FFCM techniques are evaluated by conventional validity functions. Experimental results demonstrate that sFFCM techniques efficiently handle noise interference and significantly decrease elapsed time.

Prédiction de la charge ultime de colonnes mixtes constituées de tubes remplis de béton à haute résistance : étude comparative des codes de calcul

Columns are the preferred structural application of high and very high strength concrete. The confinement of this type of concrete in steel tubes presents definite advantages from both a technical and an economical perspective. However, the present design code provisions do not allow this type of material to be considered. In certain codes, the validity limits have recently been widened, but these limits remain below the present performance of high-strength concrete. The results of a large experimental program aiming at studying the behavior of concrete columns confined in steel tubes were used in order to compare predictions by different design methods, and thus verify their applicability beyond their conventional validity limits. Based on these experimental results, a new equation is proposed to predict the ultimate load of concrete columns confined in a steel tube.Key words: high-strength concrete, ultimate load, design codes, mixed columns, confinement, slenderness.[Journal translation]