Total Variance Approach on Commercial Vehicle Handling Dynamics

The suspension roll motion can produce roll steer, which are functions of roll angle, thus producing extra lateral forces. This paper develops the total variance approach to analyze the effect of suspension roll on commercial vehicle handling dynamics. The side-slip angle unified transfer function, reaction time, transition time, damping ratio and total variance are introduced with the effect of suspension. The vehicle designers could use this approach to get optimization design parameters of vehicle without numerical calculation. For the two-axle commercial vehicles, the total variance approach is useful and could serve as an important tool for evaluating the effect of vehicle suspension roll on commercial vehicle dynamics.

PERBANDINGAN KINERJA PORTOFOLIO SAHAM DI JAKARTA ISLAMIC INDEX DAN IDX30 PERIODE 2016–2018

ABSTRAKPenelitian ini bertujuan untuk mengetahui perbedaan antara kinerja portofolio saham Jakarta Islamic Index (JII) dan IDX30 periode 2016–2018. Jenis penelitian ini adalah penelitian verifikatif dengan metode explanatory survey dan menggunakan teknik statistik komparatif. Penelitian ini menggunakan metode analisis Markowitz dengan pendekatan minimum variance. Sampel yang digunakan adalah 189 saham Jakarta Islamic Index (JII) dan 200 saham IDX30. Hasil pengujian kinerja portofolio dengan menggunakan uji beda independent sample t-test, tidak terdapat perbedaan antara kinerja portofolio Jakarta Islamic Index (JII) dengan kinerja portofolio IDX30. Kemudian, dari hasil perhitungan Sharpe Ratio pada Jakarta Islamic Index (JII) dan IDX30 pada setiap periodenya bernilai positif. Hal ini menunjukkan bahwa portofolio dari kedua indeks selalu memperlihatkan kinerja yang bernilai positif atau baik. Implikasinya adalah tidak ada return tambahan yang dapat diperoleh investor dengan cara membedakan saham yang memiliki kiteria syariah dengan yang bukan syariah. ABSTRACTThis study aims to determine the difference between the performance of the Jakarta Islamic Index (JII) and IDX30 stock portfolios for the 2016–2018 period. This type of research is a verification research with an explanatory survey method and using comparative statistical techniques. This research uses Markowitz analysis method with Minimum Variance approach. The sample used is 189 shares of Jakarta Islamic Index (JII) and 200 shares of IDX30. The results of portfolio performance testing using the independent sample t-test difference test, there is no difference between the performance of the Jakarta Islamic Index (JII) portfolio and the performance of the IDX30 portfolio. Then, from the results of the calculation of the Sharpe Ratio on the Jakarta Islamic Index (JII) and IDX30 in each period it is positive, this shows that the portfolios of the two indexes always show positive or good performance. The implication is that there is no additional return that can be obtained by investors by distinguishing stocks that have sharia criteria from those that are not sharia.

Effectiveness of offline and online learning during COVID-19 pandemic

This study aims to determine the effectiveness of offline learning and online learning with a two-factor analysis of variance approach. The subjects in this study were undergraduate students of FKIP PGRI Banyuwangi University from the history education study program. method Quasi Experimental Design which has two groups, namely online and offline, which cannot fully function to control external variables that can affect the experiment. The population of this research is the students of the Faculty of Teacher Training and Education as many as 132 students. Based on the results of the two-way ANOVA test, a significance result of 0.056> from 0.05 was obtained, it can be concluded that there is no difference between Learning Effectiveness based on study programs at the teaching and education faculty at PGRI Banyuwangi University. but if seen from the results of the significance of 0.00 <0.05, it can be concluded that there is a difference between the effectiveness of learning based on teaching methods in the faculty of teacher training and education science at the PGRI Banyuwangi university.

Students Perception about the Use of Media Platforms

With the emergence of technology, there is a remarkable growth in media platforms for accessing information. With the increase of information exchange, information about the usage of different media platforms may play a significant role in making strategies for providing information to different sections of society. Students are the major part of the population who access information through different media platforms for various purposes and make their decision accordingly. The objective of the present work is to investigate highly popular and reliable media platforms among students. For the purpose, an online survey was conducted to get information about the usage and reliability of various media platforms among students. We use analysis of variance approach to check whether all media platforms are equally popular among students and apply t-test to find highly popular and reliable media platforms. We found that different media platforms are not equally popular among students and we further observed that YouTube is a highly accessible and reliable media platform among students.

Cognitive throughput and working memory raw scores consistently differentiate resilient and vulnerable groups to sleep loss

Study Objectives Substantial individual differences exist in cognitive deficits due to sleep restriction (SR) and total sleep deprivation (TSD), with various methods used to define such neurobehavioral differences. We comprehensively compared numerous methods for defining cognitive throughput and working memory resiliency and vulnerability. Methods 41 adults participated in a 13-day experiment: 2 baseline, 5 SR, 4 recovery, and one 36h TSD night. The Digit Symbol Substitution Test (DSST) and Digit Span Test (DS) were administered every 2h. Three approaches (Raw Score [average SR performance], Change from Baseline [average SR minus average baseline performance], and Variance [intraindividual variance of SR performance]), and six thresholds (±1 standard deviation, and the best/worst performing 12.5%, 20%, 25%, 33%, 50%) classified Resilient/Vulnerable groups. Kendall’s tau-b correlations compared the group categorizations’ concordance within and between DSST number correct and DS total number correct. Bias-corrected and accelerated bootstrapped t-tests compared group performance. Results The approaches generally did not categorize the same participants into Resilient/Vulnerable groups within or between measures. The Resilient groups categorized by the Raw Score approach had significantly better DSST and DS performance across all thresholds on all study days, while the Resilient groups categorized by the Change from Baseline approach had significantly better DSST and DS performance for several thresholds on most study days. By contrast, the Variance approach showed no significant DSST and DS performance group differences. Conclusion Various approaches to define cognitive throughput and working memory resilience/vulnerability to sleep loss are not synonymous. The Raw Score approach can be reliably used to differentiate resilient and vulnerable groups using DSST and DS performance during sleep loss.