Gradation of the significance level of trends in precipitation over China

2018 ◽  
Vol 49 (6) ◽  
pp. 1890-1901 ◽  
Author(s):  
Ping Xie ◽  
Yuxi Zhao ◽  
Yan-Fang Sang ◽  
Haiting Gu ◽  
Ziyi Wu ◽  
...  
Keyword(s):  
Correlation Coefficient ◽  
Global Climate ◽  
Kendall Test ◽  
Mean Value ◽  
Annual Precipitation ◽  
Significance Level ◽  
Monte Carlo Experiments ◽  
Dispersion Degree ◽  
Significance Levels ◽  
The Relationship

Abstract How to accurately detect and estimate the significance level of trends in hydroclimate time series is a challenge. Building on correlation analysis, we propose an approach for evaluating and grading the significance level of trend in a series, and apply it to evaluate the changes in annual precipitation in China. The approach involved first formulating the relationship between the correlation coefficient and trend's slope. Four correlation coefficient thresholds are then determined by considering the influence of significance levels and data length, and the significance of trends is graded as five levels: no, weak, moderate, strong and dramatic. A larger correlation coefficient reflects a larger slope of trend and its higher significance level. Results of Monte-Carlo experiments indicated that the correlation coefficient-based approach not only reflects the magnitude of a trend, but also considers the influence of dispersion degree and mean value of the original series. Compared with the Mann–Kendall test used commonly, the proposed approach gave more accurate and specific gradation of the significance level of trends in annual precipitation over China. We find that the precipitation trends over China are not uniform, and the effects of global climate change on precipitation are not strong and limited to some regions.

scholarly journals Assessment of reliability of linear relationship between spatially distributed autocorrelated variables

2018 ◽  
pp. 201-209
Author(s):  
Olexandr Mkrtchian
Keyword(s):  
Spatial Autocorrelation ◽  
Correlation Coefficient ◽  
Spatial Data ◽  
Degrees Of Freedom ◽  
Statistical Significance ◽  
Effective Sample Size ◽  
Significance Level ◽  
Spatially Distributed ◽  
Significance Levels ◽  
The Relationship

The paper deals with the problem of the assessment of the reliability of the relationship between variables when these variables show a level of spatial autocorrelation (similarity of values between near locations). Relationships between characteristics are being characterized by two different, while similar properties: the strength and the reliability. The commonly used correlation coefficient measures the relationship’s strength and cannot determine by its own whether the relationship is statistically significant. In return, statistical significance is measured with p-level, which shows the probability that the relationship revealed in the sample is non-existent in population. Significance level depends not only on the strength of the relationship but also on the degrees of freedom. Its calculation is based on the assumption of the independent samples. Yet it is often not the case when spatial data are being analyzed. These data are usually characterized by spatial autocorrelation, which leads to highly inflated degrees of freedom and overestimated significance levels. The method to deal with this problem is proposed, based on (Clifford, Richardson, Hemon, 1989). It has been implemented with R function that takes as an input raster layers and by analyzing their autocorrelation structure calculates the effective sample size. On the basis of the latter the variance of correlation coefficient r, its p-level and confidence intervals are calculated as outputs of the function. The created function has been tested by analyzing relationships between terrain parameters (elevation and slope) and land cover characteristic (NDVI index) with data gathered for a test area in the Ukrainian Carpathians and three its subareas. Key words: autocorrelation, statistical significance, R, spatial relationships.

scholarly journals HUBUNGAN KEDISIPLINAN DAN PEMAHAMAN AYAT-AYAT AL-QUR’AN DENGAN AKHLAK SISWA

QATHRUNÂ ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 1
Author(s):  
Vivi Novianti ◽  
Hunainah Hunainah
Keyword(s):  
Correlation Coefficient ◽  
Quantitative Method ◽  
Mean Value ◽  
Student Discipline ◽  
Descriptive Approach ◽  
The Relationship

The objectives of this study were 1) to determine student discipline, 2) to determine the students 'understanding of the verses of the Koran, 3) to determine the students' morals, 4) to determine the relationship between discipline and student morals, 5) to determine the relationship between understanding the verses. -say of the Al-Qur'an students with student morals, 6) to determine the relationship between discipline and understanding of the verses of the Qur'an together with the students' morals. The method used in this research is a quantitative method with a descriptive approach, namely to obtain an overview of the relationship between discipline and understanding of the verses of the Qur'an related to morals (surah Al-Ahzab verse 21, surah Al-Ahqof verse 15 and surah Ali. Imron 110) with the morals of MAN 2 Serang City students. The result of the research states that discipline is included in the good category with a mean value of 127.72, understanding of the verses of the Qur'an is in the medium category with a mean acquisition of 73.92, student morals are in the very good category with mean acquisition of 151.44, the coefficient relationship The correlation between the discipline and the students' morals is 0.749, the correlation coefficient of understanding the verses of the Qur'an with the students' morals is 0.218 and the relationship between discipline and understanding of the verses of the Qur'an together with the students' morals has a correlation coefficient of 0.749 which means it has an influence on student morals by 74.9%. 

scholarly journals Trend analysis of rain indicators for the state of Bahia, Brazil

2020 ◽  
Vol 4 (2) ◽  
pp. 67-74
Author(s):  
Yagho de Souza Simões ◽  
Heráclio Alves de Araújo ◽  
Eduardo Cohim
Keyword(s):  
Climate Change ◽  
Linear Regression ◽  
Global Climate Change ◽  
Global Climate ◽  
Specific Region ◽  
The State ◽  
Annual Precipitation ◽  
Precipitation Regime ◽  
Historical Series ◽  
Significance Levels

The concern about the climate issue has been increasing since climate change influence the water resources system. For this reason, this study sought to identify the presence of trends in the historic series of two meteorological variables: total annual precipitation and number of rain days, in the state of Bahia, Brazil, in order to verify if the precipitation regime is being affected by the global climate change. Two trend tests were applied: Mann-Kendall and Linear Regression, with significance levels of 5% and 10%, in the historical series of 32pluviometric stations distributed throughout the state. The results of the two testes were similar, which guarantees that both can be used for detection of changes in rain pattern. The study confirms that in a specific region of Bahia, more specifically in the central and eastern areas, there is a reduction trend in the historical series of annual precipitation. Regarding the number of rain days, no trend conclusions were observed.

scholarly journals HUBUNGAN ANTARA KONSEP DIRI DENGAN KECENDERUNGAN GAYA HIDUP HEDONISME PADA MAHASISWI PSIKOLOGI UST YOGYAKARTA

2017 ◽  
Vol 5 (2) ◽  
pp. 45
Author(s):  
Ayentia Brilliandita ◽  
Flora Grace Putrianti
Keyword(s):  
Correlation Coefficient ◽  
Negative Relationship ◽  
Female Students ◽  
The Self ◽  
Self Concept ◽  
Measuring Instrument ◽  
Significance Level ◽  
The Relationship ◽  
Program Version

ABSTRACT  This study aims to determine the relationship between self-concept and lifestyle trends hedonism student of Psychology, University of SarjanawiyataTamansiswaYogyakart. The hypothesis of this study is that there are ties between the negative self-concept and lifestyle of hedonism on a college student.The subjects were female students of UST Psychology Yogyakarta, 18-22 years old, female, amounting to 87 people. Measuring instrument used was a self-concept scale and the scale of the lifestyle of hedonism. Analysis of data using Product Moment correlation with SPSS statistics program version 17.0 for Windows.Based on the analysis Product Moment correlation coefficient between the variables of self-concept and lifestyle trends hedonism is -0.382 with a significance level of P = 0.000 (p <0.05). This shows that the hypothesis that there is a negative relationship between self-concept and lifestyle of hedonism in coed acceptable. This means that the lower the self-concept, the higher the tendency of hedonistic lifestyle, otherwise the higher the self-concept, the lower the tendency of hedonism lifestyle.Keywords: Adolescent Self-Concept, Lifestyle Trends Hedonism.

scholarly journals Kecerdasan Emosi dan Perilaku Agresi di Social Media Pada Remaja

2017 ◽  
Vol 7 (2) ◽  
pp. 82
Author(s):  
Waya Ratna Dewi ◽  
Siti Ina Savira
Keyword(s):  
High School ◽  
Social Media ◽  
Emotional Intelligence ◽  
Aggressive Behavior ◽  
Correlation Coefficient ◽  
Senior High School ◽  
Significance Level ◽  
The Relationship

This study was aimed to examine the relationship betwen emotional intelligence and aggressive behavior on social media among students of state senior high school (SMA Negeri) 1 “X” in  Gresik regency. There were 232 students involved in this study. This study hypothesizes that emotional intelligence is correlated to aggressive behavior on social media among the subjects. Data collected using emotional intelligence and aggressive behavior scales and analyzed using Pearson’s product moment. The result shows that the correlation coefficient value is 0,859 (r = 0,859) with the significance level 0.000. The significance level is less than 0,005 (p < 0.005) which means that the hypothesis of this study is accepted. It can be concluded from the result that there is a significant correlation between emotional intelligence and aggressive behavior on social media among the subjects. The positive value of the coefficient shows that the higher the level of emotional intelligence of the students, the less aggressive their behaviors on social media will be, and vice versa.Abstrak: Penelitian ini bertujuan untuk mengetahui apakah ada hubungan antara kecerdasan emosi dengan perilaku agresivitas di social media pada remaja SMA Negeri 1 “X” Gresik. Hipotesis kerja (Ha) yang diajukan adalah sebagai berikut. Ada Hubungan antara kecerdasan emosi dengan perilaku agresi di social media pada remaja siswa SMAN 1 “X” Gresik. Subjek dalam penelitian ini adalah 232 siswa. Data dikumpulkan menggunakan kuesioner dalam bentuk skala kecerdasan emosi dan perilaku agresi di media sosial. Teknik analisis data menggunakan korelasi product moment. Hasil analisis data menunjukan nilai koefisien korelasi sebesar 0,859 (r = 0,859) dengan taraf signifikasi 0,000 (p<0,005). Hasil tersebut menunjukkan bahwa ada hubungan yang signifikan antara kecerdasan emosi dengan perilaku agresi di social media pada subjek penelitian, dan nilai positif menunjukan hubungan searah antara dua variabel yaitu kecerdasan emosi dengan perilaku agresivitas di social media. Semakin tinggi tingkat kecerdasan emosi yang dimiliki siswa maka akan semakin rendah perilaku agresi di social media, begitu pula sebaliknya.

scholarly journals Corellation between mother's knowledge and husband's support for the success of the Lactational Amenorrhea Method (LAM)

2021 ◽  
Vol 29 (3) ◽  
pp. 91
Author(s):  
Wahyunnisa Indrarosiana ◽  
Ernawati Ernawati ◽  
Ivon Diah Wittiarika
Keyword(s):  
Correlation Coefficient ◽  
Exclusive Breastfeeding ◽  
Rank Correlation ◽  
P Value ◽  
Inclusion Criteria ◽  
Significance Level ◽  
Lactational Amenorrhea ◽  
Lactational Amenorrhea Method ◽  
The Relationship ◽  
Spearman Rank Correlation Test

HIGHLIGHTS 1. Lactational Amenorrhea Method (LAM) is one of the natural contraception methods of postpartum women.2. Mothers' knowledge and husband's support for LAM contraceptive method was suggested to contribute to its success.3. Research and statistical instruments used found that the success of LAM contraceptive was related to mothers' knowledge, but not related to husband's support. ABSTRACTObjectives: This study aims to analyze the relationship between mother's knowledge and husband's support for the success of LAM contraception in Brengkok Village, Brondong District, Lamongan Regency, East Java.Materials and Methods: This study is an analytic observational study with a sample of 46 mothers who gave exclusive breastfeeding to their babies who met the inclusion criteria. The research instrument used a questionnaire to determine the level of mother's knowledge and husband's support about exclusive breastfeeding. Spearman Rank Correlation Test was used for data analysis with a significance level of 0.05.Results: More than 50% of respondents (25 respondents) successfully used the LAM method to prevent pregnancy. Statistical test showed that there was a relationship between mother's knowledge and success of LAM contraception with p value (0.000), with a correlation coefficient of 0.523. Meanwhile, husband's support is not related to the success of LAM contraception with p value (0.461) with a correlation coefficient of 0.111.Conclusion: Mother's knowledge is related to the success of LAM contraception, and there is no relationship between husband's support and the success of LAM contraception.

Cloud amount uncertainty in merged CloudSat-CALIPSO radar-lidar observations

2020 ◽  
Author(s):  
Andrzej Kotarba ◽  
Mateusz Solecki
Keyword(s):  
Global Climate ◽  
Statistical Significance ◽  
Cloud Amount ◽  
Grid Cell ◽  
Sampling Interval ◽  
Mean Value ◽  
Point Estimation ◽  
Dimensional Structure ◽  
Significance Level ◽  
Uncertainty Range

&lt;p&gt;Three dimensional structure of cloud cover is one of the Essential Climate Variable required for accurate monitoring of the state and change of global climate. Joint CloudSat-CALIPSO space mission have provided the most reliable and comprehensive 3D information on cloud distribution worldwide to date. However, the data resulted from observations collected every 16 days &amp;#8211; sampling interval which can be considered infrequent for most of climate-oriented applications. The reliability of the data also depends on cloud regime, and area (grid cell size) over which the data are aggregated, further complicating the uncertainty aspect of lidar-radar profiling missions. The important question related to the CloudSat-CALIPSO dataset is whether 16-day revisit period for CloudSat-CALIPSO mission is sufficient to provide a climate characteristics at high statistical significance? We address that problem evaluating the full CloudSat-CALIPSO record (2006-2011), available to the scientific community as 2B-GEOPROF-LIDAR product. The analysis focuses on two aspects. First, we perform a point estimation to determine the minimum significance level at which the lidar-radar data (mean value) is statistically significant. Second, using a bootstrap approach we calculate confidence intervals for the mean value at fixed .95 and .99 thresholds. Therefore we reveal how wide is the actual uncertainty range at 16-day revisit. The analysis accounts for grid box size over which individual lidar-laser profiles were aggregated. The study was founded by National Science of Poland under the contract no. UMO-2017/25/B/ST10/01787.&lt;/p&gt;

Boundary-crossing probabilities of some random fields related to likelihood ratio tests for epidemic alternatives

1993 ◽  
Vol 30 (01) ◽  
pp. 52-65
Author(s):  
Qiwei Yao
Keyword(s):  
Likelihood Ratio ◽  
Random Fields ◽  
Mean Value ◽  
Likelihood Ratio Tests ◽  
Boundary Crossing ◽  
Square Wave ◽  
Monte Carlo Experiments ◽  
Wave Drift ◽  
Significance Levels ◽  
Crossing Probabilities

We consider the likelihood ratio tests to detect an epidemic alternative in the following two cases of normal observations: (1) the alternative specifies a square wave drift in the mean value of an i.i.d. sequence; (2) the alternative permits a square wave drift in the intercept of a simple linear regression model. To develop the approximations for the significance levels leads us to consider boundary-crossing problems of some two-dimensional discrete-time Gaussian fields. By the method which was proposed originally by Woodroofe (1976) and adapted to study maxima of some random fields by Siegmund (1988), some large deviations for the conditional non-linear boundary-crossing probabilities are developed. Some results of Monte Carlo experiments confirm the accuracy of these approximations.

scholarly journals Relationship between disaster knowledge and environmental culture with disaster preparedness behaviour

2020 ◽  
Vol 1 (1) ◽  
pp. 23-27
Author(s):  
Rosadi Rosadi ◽  
Isman Kadar ◽  
Yossa Istiadi
Keyword(s):  
Correlation Coefficient ◽  
Significant Relationship ◽  
Disaster Preparedness ◽  
Random Sampling ◽  
Statistical Test ◽  
Coefficient Of Determination ◽  
Significance Level ◽  
Independent Variables ◽  
Disaster Knowledge ◽  
The Relationship

This research consists of two independent variables, the disaster knowledge and environmental culture, and a dependent variable of disaster preparedness behaviour. The objective is to determine the relationship between disaster knowledge and environmental culture with disaster preparedness behaviour, as well as the relationship between both of the together with disaster preparedness behaviour. The study was conducted through 166 students of three senior high schools in the District of West Karawang, West Java, which taken by proportional random sampling. The method of survey was employed in this study and the data analyzed by statistical test of correlation and simple linier regression as well as multiple linear correlation and regression, which was conducted at significance level of α = 0.01 and α = 0.05. Based on the results, it was found that there was a positive and significant relationship between disaster knowledge and disaster preparedness behaviour with a correlation coefficient value of ry1 = 0.22 and a coefficient of determination value of (r2) = 0.049. There is a positive and significant relationship between environmental culture and disaster preparedness behaviour with a correlation coefficient value of ry2 = 0.25 and a coefficient of determination value of (r2) = 0.064. There is a positive and significant relationship between disaster knowledge and environmental culture together with disaster preparedness behaviour with a correlation coefficient value of ry12 = 0.32 and a coefficient of determination value of (r2) = 0.097. Thus, it can be concluded that student’s disaster preparedness behaviour can be improved through either disaster knowledge and environmental culture.Penelitian ini terdiri atas dua variabel bebas, pengetahuan kebencanaan dan budaya lingkungan, serta satu variabel terikat yaitu perilaku siaga bencana. Tujuannya untuk mengetahui hubungan antara pengetahuan kebencanaan, budaya lingkungan dengan perilaku siaga bencana, serta hubungan keduanya secara bersama-sama dengan perilaku siaga bencana. Penelitian dilaksanakan melalui 166 siswa di tiga sekolah menengah atas, Kecamatan Karawang Barat, yang diambil secara proporsional random sampling. Metode survey digunakan dan data dianalisis dengan uji statistik korelasi dan regresi sederhana serta korelasi dan regresi linear ganda, dilakukan pada taraf signifikansi α = 0,01 dan α = 0,05. Hasil menunjukkan bahwa terdapat hubungan positif dan signifikan antara pengetahuan kebencanaan dengan perilaku siaga bencana dengan nilai koefisien korelasi ry1 = 0,22 dan koefisien determinasi (r2) = 0,049. Terdapat hubungan positif dan signifikan antara budaya lingkungan dengan perilaku siaga bencana dengan nilai koefisien korelasi ry2 = 0,25dan koefisien determinasi (r2) = 0,064. Terdapat hubungan positif dan signifikan antara pengetahuan kebencanaan dan budaya lingkungan secara bersama-sama dengan perilaku siaga bencana, dengan nilai koefisien korelasi ry12 = 0,32 dan koefisien determinasi (r2) = 0,097. Jadi, dapat disimpulkan bahwa perilaku siaga bencana siswa dapat ditingkatkan melalui pengetahuan kebencanaan dan budaya lingkungan. 

scholarly journals HUBUNGAN ANTARA KOORDINASI MATA TANGAN, POWER OTOT LENGAN DAN KEKUATAN OTOT PERUT DENGAN KEMAMPUAN PUKULAN SMASH DALAM PERMAINAN BULUTANGKIS

2016 ◽  
Vol 6 (02) ◽  
Author(s):  
Ghon Lisdiantoro
Keyword(s):  
Correlation Coefficient ◽  
Muscle Power ◽  
Abdominal Muscle ◽  
Male Students ◽  
Abdominal Muscles ◽  
Significance Level ◽  
Hand Eye Coordination ◽  
Study Population ◽  
Arm Muscles ◽  
The Relationship

<p>This study has a purpose to determine the relationship between each variable. This study used descriptive correlational study. The study population was students of IKIP PGRI MADIUN in total 60 students. The research sample was 30 male students with techniques purposive sampling. This research resulted in the following conclusions: (1) there is a significant correlation between hand-eye coordination with the ability to smash, the correlation coefficient of 0.550. With N = 30, 5% value rtabel 0463. Turns rhitung = 0.550&gt; 5% rtabel 0463. (2) there is a significant correlation between muscle power arm with the ability to smash, the correlation coefficient of 0.651. With N = 30, 5% value rtabel 0463. Turns r hitung = 0651&gt; r tabel 5% 0463 (3) there is a significant correlation between the strength of the abdominal muscles with the ability to smash, the correlation coefficient of 0.549. With N = 30, 5% value r tabel 0463. Turns r hitung = 0549&gt; 5% r tabel 0463. (4) there is a significant correlation between hand-eye coordination, power arm muscles and abdominal muscle strength with the ability to smash, Retrieved of 12,581 correlation coefficient, with F table db = 3 opponents 26 with a significance level of 5% = 4.64 turns F regresi price = 12.581 &gt; prices F tabel 5% = 4.64.</p>

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