scholarly journals Variation in the “coefficient of variation”: Rethinking the violation of the scalar property in time-duration judgments

2021 ◽  
Vol 214 ◽  
pp. 103263
Author(s):  
Yue Ren ◽  
Fredrik Allenmark ◽  
Hermann J. Müller ◽  
Zhuanghua Shi
Keyword(s):  
Coefficient Of Variation ◽  
Scalar Property ◽  
Time Duration

scholarly journals The precision of temporal judgement: milliseconds, many minutes, and beyond

2009 ◽  
Vol 364 (1525) ◽  
pp. 1897-1905 ◽  
Author(s):  
P.A. Lewis ◽  
R.C. Miall
Keyword(s):  
Standard Deviation ◽  
Coefficient Of Variation ◽  
Human Subjects ◽  
Short Interval ◽  
Time Measurement ◽  
Scalar Property ◽  
Timing Mechanisms ◽  
Timing Data ◽  
The Mean ◽  
Different Levels

The principle that the standard deviation of estimates scales with the mean estimate, commonly known as the scalar property, is one of the most broadly accepted fundamentals of interval timing. This property is measured using the coefficient of variation (CV) calculated as the ratio between the standard deviation and the mean. In 1997, John Gibbon suggested that different time measurement mechanisms may have different levels of absolute precision, and would therefore be associated with different CVs. Here, we test this proposal by examining the CVs produced by human subjects timing a broad range of intervals (68 ms to 16.7 min). Our data reveal no evidence for multiple mechanisms, but instead show a continuous logarithmic decrease in CV as timed intervals increase. This finding joins other recent reports in demonstrating a systematic violation of the scalar property in timing data. Interestingly, the estimated CV of circadian judgements fits onto the regression of decreasing CV, suggesting a link between short interval and circadian timing mechanisms.

Improving time duration estimation with training on working memory

2012 ◽  
Author(s):  
Yoshihiro S. Okazaki ◽  
Yukio Tsuchida ◽  
Masamichi Yuzawa ◽  
Keigo Minakuchi ◽  
Nozomi Notsuyama ◽  
...  
Keyword(s):  
Working Memory ◽  
Time Duration ◽  
Duration Estimation

400-P: High Levels of Glycemic Coefficient of Variation Are Associated with Higher Hypoglycemia Episodes in T1D Adults in a Brazilian Tertiary Hospital

Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 400-P
Author(s):  
THAIS B. BRASIL ◽  
ANDREI C. SPOSITO ◽  
BEATRIZ ADACHI ◽  
WALKYRIA M. VOLPINI ◽  
ELIZABETH J. PAVIN
Keyword(s):  
Coefficient Of Variation ◽  
Tertiary Hospital

Rainfall Prediction in South-Eastern Part of Bangladesh by Linear Regression Method

2018 ◽  
Vol 6 (6) ◽  
pp. 119
Author(s):  
Mohammad Shohidul Islam ◽  
Sultana Easmin Siddika ◽  
S M Injamamul Haque Masum
Keyword(s):  
Linear Regression ◽  
Correlation Coefficients ◽  
Rain Gauge ◽  
Regression Method ◽  
Linear Regression Method ◽  
Climate Data ◽  
Rainfall Forecasting ◽  
Statistical Parameters ◽  
Time Duration ◽  
Rainfall Prediction

Rainfall forecasting is very challenging task for the meteorologists. Over the last few decades, several models have been utilized, attempting the successful analysing and forecasting of rainfall. Recorded climate data can play an important role in this regard. Long-time duration of recorded data can be able to provide better advancement of rainfall forecasting. This paper presents the utilization of statistical techniques, particularly linear regression method for modelling the rainfall prediction over Bangladesh. The rainfall data for a period of 11 years was obtained from Bangladesh Meteorological department (BMD), Dhaka i.e. that was surface-based rain gauge rainfall which was acquired from 08 weather stations over Bangladesh for the years of 2001-2011. The monthly and yearly rainfall was determined. In order to assess the accuracy of it some statistical parameters such as average, meridian, correlation coefficients and standard deviation were determined for all stations. The model prediction of rainfall was compared with true rainfall which was collected from rain gauge of different stations and it was found that the model rainfall prediction has given good results.

KELAYAKAN DAN RISIKO USAHATANI JERUK KEPROK MADURA DI KABUPATEN SUMENEP

2013 ◽  
Vol 3 (2) ◽  
Author(s):  
Isdiantoni Isdiantoni
Keyword(s):  
Discount Rate ◽  
Coefficient Of Variation

Menurut Direktorat Budidaya Tanaman Buah Deptan (2009), potensi pengembangan tanaman jeruk keprok Madura di Kabupaten Sumenep, cukup besar yaitu seluas 400 hektar yang tersebar di 3 (tiga) kecamatan, yaitu Kecamatan Dasuk, Kecamatan Ambunten dan Kecamatan Pasongsongan. Salah satu faktor yang dapat menenunjang keberhasilan pengembangan komoditas jeruk ini, adalah kelayakan ekonomis (menguntungkan secara finansial).Dipihak lain, petani sebagai pelaku utama kegiatan pengembangan jeruk keprok Madura dan sebagai produsen, harus mengetahui kemungkinan resiko yang akan diterimanya dan besarnya keuntungan dari usaha ini. Pengetahuan terhadap hubungan antara resiko dan keuntungan ini, akan memberikan dasar pertimbangan yang rasional bagi petani dalam mengembangkan komoditas jeruk keprok Madura. Informasi/data pada penelitian ini, diperoleh dari petani jeruk keprok Madura yang bibitnya berasal dari cangkokan dan mulai dibuahkan pada umur 3 (tiga) tahun.Pengukuran kelayakan finansial usahatani jeruk keprok Madura dilakukan dengan melihat kriteria investasi, dan pengukuran terhadap hubungan antara tingkat resiko dengan keuntungan, diukur secara statistik dengan melihat koefisien variasi (coefficient of variation) dan batas bawah keuntungan. Kriteria investasi pada usahatani jeruk keprok Madura menunjukkan nilai NPV sebesar Rp. 118,342,271 (> 0), Net B/C sebesar 1.38 (> 1) dan IRR sebsar 23,7% (> discount rate), sehingga proyek usahatani jeruk keprok Madura dapat dikatakan go! (layak dilaksanakan).Periode yang diperlukan untuk menutup biaya investasi, yaitu 9 tahun 10 bulan (di bawah dari umur ekonomis proyek), sehingga proyek ini layak diusahakan. Selama periode proyek (15 tahun) nilai koefisien variasi (CV) didapatkan 0.588 (CV > 0.5) dan nilai batas bawah keuntungan (L) didapatkan sebesar Rp. (31,204,042) yang menunjukkan L < 0.  Dengan demikian, pengusahatani jeruk keprok Madura harus berani menanggung resiko (kerugian) sebesar  Rp. 31,204,042,- pada setiap proses produksi. Kata kunci: Usahatani Jeruk Keprok Madura, Kelayakan, dan Resiko Finansial

STUDY ON WET PROCESSING OF BLOCK CHILLY

2013 ◽  
Vol 3 (1) ◽  
pp. 45-50
Author(s):  
Dwi Dian Praptanto ◽  
Kurnia Herlina Dewi ◽  
Bosman Sidebang
Keyword(s):  
Water Content ◽  
Production Method ◽  
Time Data ◽  
Time Duration ◽  
Drying Time ◽  
Significance Level ◽  
Randomized Design ◽  
Wet Processing ◽  
Analysis Application ◽  
Lower Water Content

The purpose of this study is to examine the effect of drying time in weight and water content, combination effect of drying time and size of the material, and consumer acceptance to the product in the wet processing of chili blocks production. Method used in the research is completely randomized design (CRD) with two factorials are material size and drying time. Data were analyzed using ANOVA and further analysis using DMRT at 5% significance level. Organoleptic test result was analyzed using the Kruskal-Wallis and Tukey test for further analysis. Application of the equal drying time to two different size of material: rough and finest block chili, showed the result that water content of the rough block chili is lower than the finest block chilli. Application of the different drying time duration to the same size of chili showed the lower water content with increasing duration of drying time. The water content of the material tends to decrease with increasing duration of drying time. The level of consumer’s preferences to the product of wet processing of chili blocks production is equal for scents, but it’s different for color, texture and overall preferences.

Research of the activity and viability of spermatozoa at different concentrations and proportions of diluents after incubation

2020 ◽  
pp. 88-95
Author(s):  
Svitlana Lobchenko ◽  
Tetiana Husar ◽  
Viktor Lobchenko
Keyword(s):  
Plasma Concentration ◽  
Incubation Time ◽  
Coefficient Of Variation ◽  
Incubation Medium ◽  
Wide Range ◽  
Series Of Experiments ◽  
The Subject ◽  
Boar Spermatozoa ◽  
Native Plasma ◽  
Better Than

The results of studies of the viability of spermatozoa with different incubation time at different concentrations and using different diluents are highlighted in the article. (Un) concentrated spermatozoa were diluented: 1) with their native plasma; 2) medium 199; 3) a mixture of equal volumes of plasma and medium 199. The experiment was designed to generate experimental samples with spermatozoa concentrations prepared according to the method, namely: 0.2; 0.1; 0.05; 0.025 billion / ml. The sperm was evaluated after 2, 4, 6 and 8 hours. The perspective of such a study is significant and makes it possible to research various aspects of the subject in a wide range. In this regard, a series of experiments were conducted in this area. The data obtained are statistically processed and allow us to highlight the results that relate to each stage of the study. In particular, in this article it was found out some regularities between the viability of sperm, the type of diluent and the rate of rarefaction, as evidenced by the data presented in the tables. As a result of sperm incubation, the viability of spermatozoa remains at least the highest trend when sperm are diluted to a concentration of 0.1 billion / ml, regardless of the type of diluent used. To maintain the viability of sperm using this concentration of medium 199 is not better than its native plasma, and its mixture with an equal volume of plasma through any length of time incubation of such sperm. Most often it is at this concentration of sperm that their viability is characterized by the lowest coefficient of variation, regardless of the type of diluent used, which may indicate the greatest stability of the result under these conditions. The viability of spermatozoa with a concentration of 0.1 billion / ml is statistically significantly reduced only after 6 or even 8 hours of incubation. If the sperm are incubated for only 2 hours, regardless of the type of diluent used, the sperm concentrations tested do not affect the viability of the sperm. Key words: boar, spermatozoa, sperm plasma, concentration, incubation, medium 199, activity, viability, rarefaction.

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