Coefficient of variation of underwater irradiance fluctuations

2010 ◽  
Vol 53 (1) ◽  
pp. 13-27 ◽  
Author(s):  
V. L. Weber
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

2013 ◽  
Vol 3 (2) ◽  
Author(s):  
Isdiantoni Isdiantoni

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


Author(s):  
Svitlana Lobchenko ◽  
Tetiana Husar ◽  
Viktor Lobchenko

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.


2018 ◽  
Vol 5 (01) ◽  
Author(s):  
TAPAN K. KHURA ◽  
H. L. KUSHWAHA ◽  
SATISH D LANDE ◽  
PKSAHOO . ◽  
INDRA L . KUSHWAHA

Floriculture is an age-old farming activity in India having immense potential for generating selfemployment and income to farmers. However, the cost of cultivation of flower is high as compared to cereal crop. Level of mechanization for different field operations is one but foremost reason for the higher cost of cultivation. As most of the Indian farmers are marginal and small, a need for manually operated gladiolus planter was felt. The geometric properties of gladiolus corm were determined for designing the seed metering system and seed hopper of the planter. The planter was evaluated in the field when pulled by two persons as a power source and guided by a person. The coefficient of variation and highest deviation from the mean spacing was observed as 12.93% and 2.65cm respectively. The maximum coefficient of uniformity of 90.59% was observed for a nominal corm spacing of 15cm at 0.56 kmh-1 forward speed. An average MISS percentage was observed as 2.65 and 2.25 for nominal corm spacing of 15 and 20 cm. The multiple index was zero for two levels corm spacing and forward speed of operation. The QFI was found in the range of 97.2 and 97.9 percent. The average field capacity of the planter was observed as 0.02 hah-1.The average draft requirement of the planter was found as 821 ± 50.3 N.


2019 ◽  
Vol 23 (10) ◽  
pp. 4323-4331 ◽  
Author(s):  
Wouter J. M. Knoben ◽  
Jim E. Freer ◽  
Ross A. Woods

Abstract. A traditional metric used in hydrology to summarize model performance is the Nash–Sutcliffe efficiency (NSE). Increasingly an alternative metric, the Kling–Gupta efficiency (KGE), is used instead. When NSE is used, NSE = 0 corresponds to using the mean flow as a benchmark predictor. The same reasoning is applied in various studies that use KGE as a metric: negative KGE values are viewed as bad model performance, and only positive values are seen as good model performance. Here we show that using the mean flow as a predictor does not result in KGE = 0, but instead KGE =1-√2≈-0.41. Thus, KGE values greater than −0.41 indicate that a model improves upon the mean flow benchmark – even if the model's KGE value is negative. NSE and KGE values cannot be directly compared, because their relationship is non-unique and depends in part on the coefficient of variation of the observed time series. Therefore, modellers who use the KGE metric should not let their understanding of NSE values guide them in interpreting KGE values and instead develop new understanding based on the constitutive parts of the KGE metric and the explicit use of benchmark values to compare KGE scores against. More generally, a strong case can be made for moving away from ad hoc use of aggregated efficiency metrics and towards a framework based on purpose-dependent evaluation metrics and benchmarks that allows for more robust model adequacy assessment.


2021 ◽  
Vol 13 (5) ◽  
pp. 2705
Author(s):  
Hagen Deusch ◽  
Pantelis T. Nikolaidis ◽  
José Ramón Alvero-Cruz ◽  
Thomas Rosemann ◽  
Beat Knechtle

(1) Background: Compared with marathon races, pacing in time-limited ultramarathons has only been poorly discussed in the literature. The aim of the present study was to analyze the interaction of performance level, age and sex with pacing during 6 h, 12 h or 24 h time-limited ultramarathons. (2) Methods: Participants (n = 937, age 48.62 ± 11.80 years) were the finishers in 6 h (n = 40, 17 women and 23 men), 12 h (n = 232, 77 women and 155 men) and 24 h (n = 665, 166 women and 409 men) ultramarathons. The coefficient of variation (CV), calculated as SD/mean, was used to described pacing. Low scores of CV denoted a more even pacing, and vice versa. A two-way analysis of variance examined the main effects and interactions of sex and race duration on age, race speed and pacing. (3) Results: More men participated in the longer race distances than in the shorter ones and men were older and faster than women. Comparing the 6 h, 12 h and 24 h races, the finishers in the 6 h were the fastest, the finishers in the 12 h were the oldest and the finishers in the 24 h showed the most variable pacing. Furthermore, the faster running speed in the 12 h (women, r = −0.64; men, r = −0.49, p < 0.001) and the 24 h (r = −0.47 in women and men, p < 0.001) was related to less variable pacing. (4) Conclusions: These data might help runners and coaches to choose the the proper duration of a race and training programs for their athletes.


2021 ◽  
pp. 112067212110065
Author(s):  
Murat Serkan Songur ◽  
Yavuz Selim İntepe ◽  
Seray Aslan Bayhan ◽  
Hasan Ali Bayhan ◽  
Ender Şahin ◽  
...  

Purpose: In the present study we evaluate the corneal endothelium using specular microscopy in patients with obstructive sleep apnea syndrome (OSAS). Methods: The study included a total of 100 patients including 35 patients with mild OSAS, 34 patients with moderate OSAS and 31 patients with severe OSAS, and the right eyes of 30 patients as a control group. Patients were examined to exclude the possibility of ocular diseases. Cellular density in the cornea epithelium (cell/mm2), corneal thickness (µ), percentage of hexagonal cells (%) and the coefficient of variation were evaluated using a specular microscope. Results: Corneal thickness was significantly decreased in all OSAS groups when compared to the control group ( p = 0.002), while no significant difference was identified among the OSAS groups. The corneal endothelial cell density, percentage of hexagonal cells and coefficient of variation were significantly different between the OSAS groups and the control group ( p < 0.001). Conclusion: More significant impairments were noted in the corneal endothelium of the patients in the OSAS group than in the control group, and specular microscopy is in valuable in the follow-up and treatment of such patients.


Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 436 ◽  
Author(s):  
Hilary Mary Clayton ◽  
Sarah Jane Hobbs

The piaffe is an artificial, diagonally coordinated movement performed in the highest levels of dressage competition. The ground reaction forces (GRFs) of horses performing the piaffe do not appear to have been reported. Therefore, the objective of this study was to describe three-dimensional GRFs in ridden dressage horses performing the piaffe. In-ground force plates were used to capture fore and hindlimb GRF data from seven well-trained dressage horses. Peak vertical GRF was significantly higher in forelimbs than in the hindlimbs (7.39 ± 0.99 N/kg vs. 6.41 ± 0.64 N/kg; p < 0.001) with vertical impulse showing a trend toward higher forelimb values. Peak longitudinal forces were small with no difference in the magnitude of braking or propulsive forces between fore and hindlimbs. Peak transverse forces were similar in magnitude to longitudinal forces and were mostly directed medially in the hindlimbs. Both the intra- and inter-individual variability of longitudinal and transverse GRFs were high (coefficient of variation 25–68%). Compared with the other diagonal gaits of dressage horses, the vertical GRF somewhat shifted toward the hindlimbs. The high step-to-step variability of the horizontal GRF components is thought to reflect the challenge of balancing on one diagonal pair of limbs with no forward momentum.


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