scholarly journals APPLICATION OF PRINCIPAL COMPONENT ANALYSIS TO DROUGHT INDICATORS OF THREE REPRESENTATIVE CROATIAN REGIONS

2021 ◽  
Vol 12 (22) ◽  
pp. 41-55
Author(s):  
Lidija Tadić ◽  
◽  
Tamara Brleković ◽  
Kristina Potočki ◽  
Marija Leko-Kos ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Air Temperature ◽  
Principal Component ◽  
Component Analysis ◽  
Homogeneity Test ◽  
Temperature And Precipitation ◽  
Standard Normal Homogeneity Test ◽  
Seasonal Basis ◽  
The Impact ◽  
Drought Occurrence

Drought has become a very frequent hydrological event globally, including in Croatia. It can generally be explained by air temperature and precipitation changes on an annual and seasonal basis, owing to climate change. To contribute to the knowledge on drought phenomena in Croatia, the changes in air temperature and precipitation over a relatively long period between 1951 and 2018 were analyzed. The meteorological stations included in the research were Osijek, Zagreb, and Split, which represented the climate of the entire country. Drought was estimated using the standardized precipitation evapotranspiration index, which is one of the most comprehensive drought indices. Furthermore, the drought severity and duration were calculated using run theory. These parameters were tested for homogeneity using the standard normal homogeneity test. Only the air temperature exhibited inhomogeneity, with a break year in 1991 (Zagreb and Split) and 1998 (Osijek). The existence of significant temporal trends was tested using the non-parametric Mann–Kendall trend test. The probability of drought occurrence with a certain duration and severity was calculated using the copula function. Finally, principal component analysis was applied to the computed standardized Mann–Kendall test statistic (ZMK ) to define the relevance of each parameter change and their combination in drought occurrence on a seasonal basis. Drought occurrence was less recognizable from 1951 to 1991 (1998). In the second sub-period, the impact of an increasing air temperature was the most significant variable, particularly in Zagreb.

scholarly journals The impact of temporal patterns of temperature and precipitation on silver Prussian carp (Carassius gibelio) spawning events

2019 ◽  
Vol 27 (2) ◽  
pp. 106-117 ◽  
Author(s):  
D. L. Bondarev ◽  
O. M. Kunah ◽  
M. P. Fedushko ◽  
N. L. Gubanova
Keyword(s):  
Principal Component Analysis ◽  
Water Temperature ◽  
Air Temperature ◽  
Principal Components ◽  
Temperature Regime ◽  
Linear Trend ◽  
Principal Component ◽  
Component Analysis ◽  
Water Bodies ◽  
Temperature And Precipitation

It was revealed that Gibel carp, Carassius gibelio (Bloch, 1782) spawning phenology is determined by regular patterns of variability in temperature and precipitation over the period of time after spawning in the previous year. The sensitivity to temperature of water as a stimulus to spawning was shown as being dependent on the characteristics of the environment and fish development trajectories over the previous year. Information about fish spawning was collected in the Dnipro-Orylskiy Nature Reserve in the following locations: Nikolayev system of water bodies, River Protoch system and the Obukhov floodplain, the channel of the River Dnipro, water bodies of the Taromske ledge. The materials that formed the basis of this research were collected from the waters of the reserve in the years 1997–2018. There are dependencies between the air and water temperatures that have their own characteristics depending on the type of water body. These dependencies are described by a logistic equation. The temperature regime in water bodies of the Taromske ledge is very similar to the temperature regime of Nikolayev system of water bodies. The difference is that the spring period of the temperature increase in water bodies of the Taromske ledge comes earlier – in late February – early March. The air temperature dynamics over the year is described by the fourth degree polynomial. The residuals of the polynomial regression for each year were subjected to principal component analysis. The principal component analysis allowed us to identify 8 principal components of the temperature regimes, which together describe 59.2% of the variation of the residual of the polynomial trend. Deviations from the linear trend of the precipitation are systematic throughout the year, reflecting the uneven nature of rainfall during the year. The residuals of linear trend regression models of cumulative precipitation can be used as indicators of the dynamics characteristic of precipitation during the year. The residuals were used for principal component analysis, which revealed that the dynamics of the precipitation can be divided into five orthogonal principal components. The first five principal components explain 82.6% of the feature space variation. The timing of the onset of C. gibelio spawning in 95% of cases occurs on the 113–139th days of the year (on average, it takes place on the 125th day). Regression analysis revealed that the climate principal components and types of the lake systems can explain 79% of the variation in the timing of the onset of C. gibelio spawning. The water temperature at the time of C. gibelio spawning was exposed to natural dynamics in year aspect. The local minimum of the onset of spawning temperatures occured in the mid 2000s. Total of 69% of the water temperature variation at which spawning begins can be described by climatic predictors and water biotope types. The variation explained by some temperature principal components may be increased considerably after including as covariates such variables as the precipitation principal component and the biotope type. This principal component which represents the high frequency variation of the air temperature regime with a characteristic period 20 and 45 days has the highest explanation ability of all the components and is a constant explanatory predictor for all considered spawning characteristics.

Evaluation of the Aging Behavior of High Density Polyethylene in Thermal Oxidative Environment by Principal Component Analysis

2017 ◽  
Vol 727 ◽  
pp. 447-449 ◽  
Author(s):  
Jun Dai ◽  
Hua Yan ◽  
Jian Jian Yang ◽  
Jun Jun Guo
Keyword(s):  
Principal Component Analysis ◽  
Impact Strength ◽  
High Density Polyethylene ◽  
Tensile Modulus ◽  
Principal Component ◽  
Component Analysis ◽  
High Density ◽  
Aging Behavior ◽  
Data Set ◽  
The Impact

To evaluate the aging behavior of high density polyethylene (HDPE) under an artificial accelerated environment, principal component analysis (PCA) was used to establish a non-dimensional expression Z from a data set of multiple degradation parameters of HDPE. In this study, HDPE samples were exposed to the accelerated thermal oxidative environment for different time intervals up to 64 days. The results showed that the combined evaluating parameter Z was characterized by three-stage changes. The combined evaluating parameter Z increased quickly in the first 16 days of exposure and then leveled off. After 40 days, it began to increase again. Among the 10 degradation parameters, branching degree, carbonyl index and hydroxyl index are strongly associated. The tensile modulus is highly correlated with the impact strength. The tensile strength, tensile modulus and impact strength are negatively correlated with the crystallinity.

scholarly journals Multi-trait Analysis of Agroclimate Variations During the Growing Season in East-Central Poland (1971-2005)

2015 ◽  
Vol 29 (2) ◽  
pp. 213-219 ◽  
Author(s):  
Elżbieta Radzka ◽  
Katarzyna Rymuza
Keyword(s):  
Principal Component Analysis ◽  
Air Temperature ◽  
Meteorological Data ◽  
Principal Component ◽  
Growing Season ◽  
Component Analysis ◽  
The South ◽  
East Central ◽  
Central Poland ◽  
The North

Abstract The work is based on meteorological data recorded by nine stations of the Institute of Meteorology and Water Management located in east-central Poland from 1971 to 2005. The region encompasses the North Podlasian Lowland and the South Podlasian Lowland. Average values of selected agroclimate indicators for the growing season were determined. Moreover, principal component analysis was conducted to indicate elements that exerted the greatest influence on the agroclimate. Also, cluster analysis was carried out to select stations with similar agroclimate. Ward method was used for clustering and the Euclidean distance was applied. Principal component analysis revealed that the agroclimate of east-central Poland was predominantly affected by climatic water balance, number of days of active plant growth, length of the farming period, and the average air temperature during the growing season (Apr-Sept). Based on the analysis, the region of east-central Poland was divided into two groups (areas) with different agroclimatic conditions. The first area comprized the following stations: Szepietowo and Białowieża located in the North Podlasian Lowland and Biała Podlaska situated in the northern part of the South Podlasian Lowland. This area was characterized by shorter farming periods and a lower average air temperature during the growing season. The other group included the remaining stations located in the western part of both the Lowlands which was warmer and where greater water deficits were recorded.

scholarly journals PARAMETER FISIKA, KIMIA, DAN BIOLOGI PENCIRI HABITAT IKAN BELIDA (Chitala lopis)

2017 ◽  
Vol 15 (1) ◽  
pp. 13
Author(s):  
Arif Wibowo ◽  
Mas Tri Djoko Sunarno ◽  
Safran Makmur
Keyword(s):  
Principal Component Analysis ◽  
Discriminant Analysis ◽  
Dissolved Oxygen ◽  
Air Temperature ◽  
Oxygen Demand ◽  
Principal Component ◽  
Environmental Parameters ◽  
Component Analysis ◽  
Biological Oxygen Demand ◽  
Total Dissolved Solid

Penelitian mengenai parameter fisika, kimia, dan biologi penciri habitat ikan belida (Chitala lopis) dilakukan tahun 2005 - 2006 di perairan umum daratan di Sumatera, Kalimantan, dan Jawa. Tujuan nya adalah untuk mendapatkan informasi parameter lingkungan yang menjadi karakteristik habitat ikan belida dari berbagai badan air di Jawa, Sumatera, dan Kalimantan. Metode survei dan kegiatan laboratorium digunakan dalam penelitian ini. Parameter lingkungan yang diamati meliputi suhu udara, suhu air, Total Dissolved Solid (TDS), Daya Hantar Listrik (DHL), klorofil-a, kecepatan arus, Biological Oxygen Demand (BOD), oksigen terlarut, pH, alkalinitas, CO2 bebas, kedalaman air, dan kecerahan pada 116 lokasi pengambilan yang ditentukan secara sengaja di Sungai Tulang Bawang (Provinsi Lampung), Sungai Kampar, Sungai Siak (Provinsi Riau), Sungai Musi (Provinsi Sumatera Selatan), Sungai Citarum (Provinsi Jawa Barat), Sungai Kapuas (Provinsi Kalimantan Barat), dan Waduk Riam Kanan (Provinsi Kalimantan Selatan). Analisis data menggunakan pendekatan analisis multivariabel regresi berganda Metode Backward yang didasarkan pada Analisis Komponen Utama (Principal Component Analysis) dan pembeda (Discriminant Analysis), serta korespondensi analisis (correspondency analysis). Hasil penelitian menunjukkan habitat ikan belida dapat dibedakan menjadi tiga tipe, yaitu tipe yang menyerupai sungai utama, waduk, dan anak sungai. Pembeda utama sekaligus parameter lingkungan utama adalah parameter TDS yang paling besar, dan selanjutnya parameterparameter DHL, suhu udara, klorofil-a, kecepatan arus, BOD, Oksigen terlarut, pH, alkalinitas, dan CO2 bebas menyumbang yang paling sedikit. Kehadiran plankton genus Ulothrix dan Mytilina secara tidak langsung teridentifikasi sebagai penciri habitat spesifik ikan belida. Research on physical, chemical, and biological parameters indicating specific habitat of clown knife fish (Chitala lopis) was carried out at 2005 - 2006 in inlands waters of Sumatera, Borneo, and Java. This study purposed to obtain information of environmental parameters indicating habitat characteristic of the knife fish in various inland waters bodies in Sumatera, Borneo, and Java. Survey method and laboratory activities were employed in this research. Environmental parameters observed were air temperature, water temperature, Total Dissolved Solid (TDS), conductivity, water velocity, Biological Oxygen Demand (BOD), dissolved oxygen, pH, alkalinity, free C02, water depth, and water transparancy taken on 116 sampling stations distributing in Tulang Bawang River (Lampung Province), Kampar and Siak River (Riau Province), Musi River (South Sumatera Province), Kapuas River (West Kalimantan Province), Riam Kanan Reservoar (South Kalimantan Province), and Citarum River (West Java Province). Data analysis used multivariate approach of multiple regression of Backward Method such as Principal Component Analysis, Discriminant Analysis, and Corre spondency Analysis. The results showed that the clown knife fish habitats could be divided by three types of specific habitat, namely water bodies similar with main rivers, reservoir, and tributaries. Parameter of TDS indicated the primary differentization as well as habitat characteristics of the clown knife fish.Whilst the parameters of conductivity, air temperature, chlorophyill-a, water current, BOD, dissolved oxygen, pH, alcalinity, and free CO2 contributed less significance. The existence of plankton from genus Ulothrix and Mytilina was identified indirectly as the specific habitat of the clown knife fish.

Principal component analysis of air temperature in Belgium

1992 ◽  
Vol 45 (1) ◽  
pp. 61-63 ◽  
Author(s):  
R. Sneyers ◽  
M. Vandiepenbeeck ◽  
R. Vanlierde
Keyword(s):  
Principal Component Analysis ◽  
Air Temperature ◽  
Principal Component ◽  
Component Analysis

The Comprehensive Evaluation on Financial Performance of the Ceramic Company Based on Principal Component Analysis

2012 ◽  
Vol 512-515 ◽  
pp. 1098-1102 ◽  
Author(s):  
Bao Cheng He ◽  
Hong Tao Jiang
Keyword(s):  
Principal Component Analysis ◽  
Financial Performance ◽  
Performance Indicator ◽  
Comprehensive Evaluation ◽  
Principal Component ◽  
Component Analysis ◽  
Indicator System ◽  
Financial Report ◽  
Components Method ◽  
The Impact

The ceramic company financial performance indicator has multilayers, many dimensions and intersect characters, and the comprehensive evaluation on it is a big challenge. Firstly, this paper introduces principal component analysis theory and tool. Secondly, it constructs the four-dimensional evaluating indicator system based on “debt-paying ability, operation capability, profitability, and development capability”. In the end, based on the financial report data, this paper conducts an empirical principal component analysis on 20 typical ceramic enterprises’ financial performance. The conclusion is that the ceramic business finance performance is mainly decided by four greatest factors including “debt-paying ability, profitability, efficiency, development” and the impact of the four greatest factors upon the finance performance degree is different. This research’s innovation lies in using the principal components method to give the weight to the evaluating indicators objectively, providing not only the new tool for the ceramic enterprise financial performance assessment method’s evolution, but also the new mentality for the ceramic enterprise financial performance’s improvement.

scholarly journals Principal Component Analysis in the Nonlinear Dynamics of Beams: Purification of the Signal from Noise Induced by the Nonlinearity of Beam Vibrations

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
A. V. Krysko ◽  
Jan Awrejcewicz ◽  
Irina V. Papkova ◽  
Olga Szymanowska ◽  
V. A. Krysko
Keyword(s):  
Nonlinear Dynamics ◽  
Principal Component Analysis ◽  
Differential Equations ◽  
Geometric Nonlinearity ◽  
Nonlinear Differential Equations ◽  
Principal Component ◽  
Component Analysis ◽  
Harmonic Load ◽  
Linear And Nonlinear ◽  
The Impact

The paper discusses the impact of the von Kármán type geometric nonlinearity introduced to a mathematical model of beam vibrations on the amplitude-frequency characteristics of the signal for the proposed mathematical models of beam vibrations. An attempt is made to separate vibrations of continuous mechanical systems subjected to a harmonic load from noise induced by the nonlinearity of the system by employing the principal component analysis (PCA). Straight beams lying on Winkler foundations are analysed. Differential equations are obtained based on the Bernoulli-Euler, Timoshenko, and Sheremetev-Pelekh-Levinson-Reddy hypotheses. Solutions to linear and nonlinear differential equations are found using the principal component analysis (PCA).

Sign in / Sign up

Export Citation Format

Share Document