Impact of User Mobility on the Provided Quality of Service in Mobile Networks

U ovome radu objašnjen je razvoj mobilnih mreža kroz generacije, te za svaku generaciju zasebno su prikazane ključne činjenice. Definirana je kvaliteta usluge i detaljno objašnjeni parametri koji utječu na nju, te su prikazane definirane vrijednosti tih parametara kroz razne primjere aplikacija koje su isto tako detaljno analizirane zajedno sa zahtjevima koje postavljaju. Objašnjena je važnost mobilnosti korisnika uz razne pogodnosti, kao i vrste poziva. Navedene su metode mjerenja kvalitete usluge, te utjecaj na zadovoljstvo korisnika mobilnih mreža.This paper explains the development of mobile networks through generations, for each generation, key facts are presented separately. The quality of service and detailed parameters that affect it are defined, the values of these parameters are defined through various applications that have been analyzed in detail along with the requirements they set. The importance of user mobility has been explained with various benefits, as well as types of calls. The methods of measuring quality of service and the impact on the satisfaction of mobile network users are mentioned

Impact of User Mobility on the Provided Quality of Service in Mobile Networks

U ovome radu objašnjen je razvoj mobilnih mreža kroz generacije, te za svaku generaciju zasebno su prikazane ključne činjenice. Definirana je kvaliteta usluge i detaljno objašnjeni parametri koji utječu na nju, te su prikazane definirane vrijednosti tih parametara kroz razne primjere aplikacija koje su isto tako detaljno analizirane zajedno sa zahtjevima koje postavljaju. Objašnjena je važnost mobilnosti korisnika uz razne pogodnosti, kao i vrste poziva. Navedene su metode mjerenja kvalitete usluge, te utjecaj na zadovoljstvo korisnika mobilnih mreža.This paper explains the development of mobile networks through generations, for each generation, key facts are presented separately. The quality of service and detailed parameters that affect it are defined, the values of these parameters are defined through various applications that have been analyzed in detail along with the requirements they set. The importance of user mobility has been explained with various benefits, as well as types of calls. The methods of measuring quality of service and the impact on the satisfaction of mobile network users are mentioned

Impact of User Mobility on the Provided Quality of Service in Mobile Networks

U ovome radu objašnjen je razvoj mobilnih mreža kroz generacije, te za svaku generaciju zasebno su prikazane ključne činjenice. Definirana je kvaliteta usluge i detaljno objašnjeni parametri koji utječu na nju, te su prikazane definirane vrijednosti tih parametara kroz razne primjere aplikacija koje su isto tako detaljno analizirane zajedno sa zahtjevima koje postavljaju. Objašnjena je važnost mobilnosti korisnika uz razne pogodnosti, kao i vrste poziva. Navedene su metode mjerenja kvalitete usluge, te utjecaj na zadovoljstvo korisnika mobilnih mreža.This paper explains the development of mobile networks through generations, for each generation, key facts are presented separately. The quality of service and detailed parameters that affect it are defined, the values of these parameters are defined through various applications that have been analyzed in detail along with the requirements they set. The importance of user mobility has been explained with various benefits, as well as types of calls. The methods of measuring quality of service and the impact on the satisfaction of mobile network users are mentioned

Phytosociological analysis of beech forests in the Žumberak and Samobor highlands (Croatia)

The Žumberak and Samobor highlands are situated in the north-western part of Croatia where the characteristics of the Dinarides, the Alps and the Pannonian Plain meet. The greater part of the area is occupied by beech forests. The aim of the study was to determine the syntaxonomic affiliation of these forest communities, and to explore their floristic and main ecological features. Numerical analyses of floristic compositions were conducted on a data-set consisting of 144 new relevés and 99 relevés from the existing literature. Relevés were made following the standard Braun-Blanquet method. For descriptions of ecological conditions Ellenberg’s indicator values were used. Six plant associations and two subassociations of beech forests were established in Luzulo-Fagion and Aremonio-Fagion alliances. The higher altitudes of the studied area are occupied by ass. Cardamini savensi-Fagetum, whereas the lower altitudes are occupied by ass. Lamio orvalae-Fagetum and Hacquetio-Fagetum. Ass. Hacquetio-Fagetum spreads on southern slopes and ridges, whereas ass. Lamio orvalae-Fagetum occurs in ditches and on northern slopes. In the warmer habitats with shallow soils on a dolomite base ass. Ostryo-Fagetum occurred. A small part of the area is characterized by silicate substrate which is occupied by ass. Luzulo-Fagetum and Gentiano asclepiadeae-Fagetum

Photosyntesis Intensity andVegetative Growth of Pedunculate Oak (Quercus roburL.) in Common-Garden Experiment

U radu je analiziran utjecaj mikrostaništa na fiziološke značajke i vegetativni rast hrasta lužnjaka. Istraživanje je provedeno na dvije pokusne plohe koje se odlikuju različitim kemijskim značajkama, sadržajem vlage i temperaturom tla. Cilj rada bio je utvrditi utjecaj različitih kemijskih značajki tla na vegetativni rast i intenzitet fotosinteze hrasta lužnjaka, kao i odnos koncentracije klorofila i intenziteta fotosinteze. Biljke uzrasle na tlu s većom koncentracijom humusa, dušika, fosfora i kalija imaju veći intenzitet fotosinteze, veću koncentaraciju klorofila te bolji vegetativni rast. Zbog povoljnog odnosa volumetrijskog sadržaja vlage u tlu i vodnog potencijala istraživanih biljaka, njihov značajniji utjecaj na fiziološke i vegetativne značajke hrasta lužnjaka nije utvrđen. Rezultati ukazuju na visoku pozitivnu korelaciju između indeksa ukupnih klorofila u proljetnim listovima i većine fizioloških te vegetativnih značajki istraživanih biljaka.The effect of various types of environmental stress factors on forest trees is most often manifested through the reduced absorption of mineral nutriments. This results in lowered efficiency of photosynthetic pigments on the leaf’s cellular level and production of insufficient amounts of carbohydrates necessary for normal vegetative growth. Due to sudden increase in concentration of carotenoids in relation to chlorophyll, which is susceptible to a sudden destruction under the effect of stress factors, a change takes place in the relative amounts of chlorophyll and carotenoids. Because of this, the leaves in the crown of a tree temporarily lose their green color and turn yellow, which is indicative of plant’s lack of nitrogen nutrition, i.e. the nitrogen deficiency in the soil. The role of nitrogen as a plant nutriment is connected with numerous physiological processes responsible for successful growth and development of plants. For example, nitrogen is an essential element responsible for an uninterrupted continuation of photosynthetic process and vegetative plant growth, primarily because of its role in the synthesis of chlorophyll and certain proteins, such as ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco), which is responsible for CO2assimilation. In the previous studies of forest trees, significant differences were determined in the intensity of photosynthesis and vegetative development regarding the diverse conditions in the habitats. These variations are usually due to the lengths of summer droughts and high temperatures, the intensity of illumination, and the differences between dry and wet years. The aim of this study was to, (1) determine the effect of various chemical characteristics of the soil on the intensity of photosynthesis and the vegetative growth of pedunculate oak, (2) establish a connection between content index of the total amount of chlorophyll in the leaf, and the intensity of photosynthesis and the vegetative growth of pedunculate oak. The study was conducted during the vegetative period in 2010, on 4-yearold plants, planted with 2 – 2,5 meters of space between plants. Based on visual differences in the leaf color, two plots have been set aside – the chlorotic and the control plots (without chlorosis). Each field contained 8 plants, i.e. 16 in total. The average height of the plants under study before the start amounted to 1.96 ± 0.44 meters, and the diameter of the trunk 2.5 centimeters, measured 30 centimeters above ground. In order to determine the differences in the soil’s chemical characteristics between the two studied plots, the samples were taken on the depth of 0–30 centimeters. The soil reaction was determined with a potentiometer in the suspension of soil and water, i.e. soil and nKCl. Humus was determined by the Thorin method, and the total nitrogen level by the Kendahl method. The content of physiologically active phosphorus and potassium was determined by the Al-method. The study determined height and diameter increment for the plants studied, and also height and diameter increment for primary branches of each plant. The number of spring and summer shoots with its attending leaves was also determined. Based on the number and surface area of leaves, as well as the projection of crown surface on the ground, index of leaf surface was calculated for each tree. The measurements of photosynthesis intensity and the index of total chlorophyll content were performed early in September. The photosynthesis intensity was measured with the help of the infrared gas analizer portable device LCpro + (ADC BioScientific). While taking photosynthesis intensity measurements, each leaf was subjected to illumination intensity of 1500 µmol m-2 s-1, CO2concentration of 380 ± 10 µmol mol-1and the air temperature of 25 ± 2 °C. The chlorophyll content index was determined by using chlorophyll content meter CCM-200. By using a portable chamber for measuring water potential, the measurement of water potential was taken in the leaves (.) of plants under study. The chemical characteristics of the soil in the test plots were shown in Table 1. There was an extremely acidic reaction in the chlorotic plot, and acidic in the control plot. The chlorotic plot was marked by an extremely low nitrogen supply, while the control plot had a medium to good nitrogen supply. The content of physiologically active phosphorus in the chlorotic plot was extremely low, while the control plot was averagely supplied with physiologically active phosphorus. Both plots under study featured accessible potassium levels on the lower margins of an average supply. The humus content in the studied plots was very low, especially in the chlorotic plot. Statistically significant difference in the measured values of water potential of the plants grown in the plots was determined only during noon measuring throughout July. In August and September, statistically significant differences in the measured values of water potential were not determined (Table 3). All the parameters of the vegetative growth of the plants under study which were grown on the control plot had statistically significant higher values compared to the plants grown on the chlorotic plot, except for the number of primary branches, which showed no statistically significant differences between the two studied plot trials (Table 4). Leaf surface index, value of which was taken in the middle and near the end of the vegetative cycle, was statistically significantly higher in the control plot than in the chlorotic plot (Figure 2). There was statistically significant difference in the intensity of photosynthesis measured on spring leaves of studied plants between the control and the chlorotic plot. The intensity of photosynthesis on the control plot was 28.4 µmol CO2m-2 s-1, while its value on the chlorotic plot was 19.3 µmol CO2m-2 s-1. Content index values of total chlorophyll in the leaves of the studied plants were statistically significantly different regarding the plots under study, no matter whether the measuring of chlorophyll content was conducted on spring or summer leaves (Figure 4). Regression analysis determined a high positive correlation between the content index of total chlorophyll measured on spring leaves of studied plants with the intensity of photosynthesis, leaf surface index, tree’s girth increment, and also length and girth increment in the primary branches (Table 5). The correlation between content index of total chlorophyll and tree’s height increment was very weak. The results of the study indicate that the soil’s chemical characteristics have an effect on the photosynthetic activity and the concentration of chlorophyll in the leaves of pedunculate oak. The higher values of the total chlorophyll’s content index and the intensity of photosynthesis were recorded for plants grown on the soil with a higher concentration of humus, nitrogen, phosphorus and potassium. Positive correlations between the content indexes of total chlorophyll in leaves and the intensity of photosynthesis, as well as most of the parameters of vegetative growth, indicate the possibility of successful application of chlorophyll measuring methods when determining vitality of particular trees and forest stands of pedunculate oak

Influence of Light on Natural Regeneration of Pedunculate Oak (Quercus roburL.) in the Maksimir Forest Park in Zagreb

U park-šumi Maksimir, u mješovitoj sastojini hrasta lužnjaka i običnoga graba (Carpino betuli-Quercetum roboris/Anić 1959/ Rauš 1969), analiziran je utjecaj svjetla na brojnost i kvalitetu mladog hrastovog naraštaja. Pokusna ploha obuhvatila je dvije pomladne jezgre u razvojnom stadiju mladika i površinu između jezgri u fazi ponika te mlađeg i starijeg pomlatka. Analiza podataka pokazala je da se prirodno pomlađivanje na malim površinama u park-šumi Maksimir odvija uspješno. Broj biljaka po jedinici površine je zadovoljavajući i iznosi 8,3 kom/m2. Prema vrsti smjese to je mješovita sastojina hrasta lužnjaka i običnoga graba s manjim udjelom divlje trešnje (PrunusaviumL.), klena (Acer campestreL.), lipe (Tiliasp.) i mliječa (A. platanoidesL.). Prednost mješovitih sastojina ogleda se u biološkoj i ekološkoj ravnoteži, a to su glavni ciljevi gospodarenja u park-šumi Maksimir. No, kvaliteta mladog na raštaja hrasta lužnjaka je upitna. Posljedica visoke gustoće biljaka na pom-lad noj površini je visok prosječni koeficijent vitkosti mladog hrastovog naraštaja. Velik udio deformiranih debala, loše razvijenih krošnji i prevelika zastupljenost korovske vegetacije posljedica su nenjegovanja pomlatka. Utvrđene su prosječne godišnje relativne vrijednosti difuznog i izravnog svjetla u pojedinim razvojnim stadijima hrasta lužnjaka. Ovisnost broja biljaka u različitim razvojnim stadijima o svjetlosnim uvjetima pojedinog mikrostaništa potvrđena je ?2testom. Dobivena je jaka pozitivna linearna ko re lacija između prosječnog visinskog prirasta hrasta lužnjaka i vrijednosti izravnog svjetla (r = 0,5809).In a forest park Maksimir, in a mixed forest stand of Pedunculate Oak and Common Hornbeam (Carpino betuli-Quercetum roboris/Anić 1959/ Rauš 1969), influence of light conditions on number and quality of young oak growth was investigated. Experimental plot covered two regeneration gaps and the space between, including the trees in a different stage of development (seedlings, saplings and young trees). Measurements were taken in the winter 2006 and spring 2007 in a single plot within the stand. The plot was divided in 105 sub-plots of 1.5 m x 1.5 m and on each sub-plot height (cm), tree length (cm), ground level diameter (mm) and last five height increments (cm) were measured. Parallel to the measurement, evaluation of stem quality, crown form and tree health state was conducted. Spatial distribution of old grown trees at the plot area, together with crown projections, was recorded. At each sub-plot a hemispherical photograph was taken. Average annual relative values of diffuse and direct light for different development stages of Pedunculate Oak were determined. Depending on the values of diffuse and direct light, four microsites (marked: A – D) with different light conditions were defined. Results indicate that natural regeneration in naturally occurring gaps could be considered successful. Average number of trees per square meter was 8.3. Species composition of naturally occurring young trees in the gap indicates a continuation of the same forest community, namely mixed forest stand of Pedunculate Oak and Common Hornbeam with a smaller share of Wild Cherry (Prunus aviumL.), Hedge Maple (Acer campestreL.), Norway Maple (A.platanoidesL.) and Lime (Tiliasp.). Mixed forest stands are of great biological and ecological value, but also attractive to the park visitors. Maintaining them and their stability is a main management goal in this forest park. However, in naturally occurring gaps in the absence of silvicultural treatments the quality of young trees is questionable. High density of young growth at our plot resulted with high tree slenderness coefficient of 97,7. Share of deformed tree stems was significant (30.3 %), as well as share of badly developed tree crowns (44.3 %). Great abundance of weed vegetation was recorded and can be attributed to the lack of silvicultural treatments during regeneration. Chi-square test showed statistically significant dependence of number of young oak growth in different development stages with respect to the light conditions at microsite. Lower values of direct and diffuse light (microsite C) correspond with great number of oak seedlings. Surviving of oak seedling in low light conditions confirms the fact that in first few years oak is shade tolerant. However, great abundance of oak saplings at microsites A (lower values of direct and higher values of diffuse light) and D (higher values of direct and lower values of diffuse light) indicates that oak, when it arrives to the stage of saplings, favours higher light conditions. This is further corroborated at microsite B (with high values of direct and diffuse light) where young oak trees were most abundant. Quality of oak saplings and young trees was better at microsite B. Young oak trees grown in high light conditions obtained greater height increment and stem verticality. High positive correlation is obtained between Pedunculate Oak average height increment and average values of direct light (r = 0,5809)

Odabir autohtonih aromatičnih i ljekovitih trajnica za uređenje terapijskih urbanih prostora na Mediteranu

Kroz dugo vremensko razdoblje, aromatično, ljekovito, kao i začinsko bilje pronalazi svoju primjenu u različite svrhe. U novije vrijeme, kada raste svijest i potreba o sve većoj integraciji prirodnog okruženja u urbanoj sredini (biofilni dizajn), sve je aktualnije uređenje unutarnjih i vanjskih zelenih prostora s terapijskom i rehabilitacijskom namjenom. Aromatična i druga svojstva takvih biljaka potencijalnom prostoru dodaju novi aspekt (uz onaj dekorativni) u vidu jačanja motoričkih, senzoričkih, kognitivnih te socijalnih potencijala osjetljivih skupina posjetitelja, čime doprinose njihovom skladnijem životu i zdravlju. Specifičnim mirisima, raznolikošću oblika, struktura, boja i listova, ove biljke omogućuju višeosjetilni doživljaj uređenog prostora. S obzirom na svoje biološke značajke i ekološke zahtjeve, iziskuju različite stupnjeve njege i održavanja te ih u tom pogledu treba promišljeno odabrati i uklopiti u prostor koji se uređuje kako bi kontinuirano održavale svoju namjenu, kako u estetskom, tako i u terapijskom smislu, pružajući potpuni učinak za osjetila posjetitelja

Nondestructive estimation of photosynthetic pigment concentrations in pedunculate oak (Quercus robur L.) leaves

U radu je predstavljena nedestruktivna procjena koncentracije fotosintetskih pigmenata (ukupnih klorofila i karotenoida) u lišću hrasta lužnjaka pomoću prijenosnog optičkog klorofilmetra CCM-200. Istraživanje je provedeno 2015. godine na biljnom materijalu izloženom različitim tretmanima vlažnosti tla. U kontrolnom tertmanu sadržaj vlage u tlu održavan je iznad poljskog vodnog kapaciteta, dok je u sušnom tretmanu biljkama voda bila uskraćena 112 dana (1. 4. – 21. 7.). U drugom dijelu vegetacijskog razdoblja (22. 7. – 22. 10.) u oba tretmana vlaga tla održavana je iznad poljskog vodnog kapaciteta. Na temelju lišća uzorkovanoga istovremeno u oba tretmana i to sredinom jeseni (27. 10.) izrađene su kalibracijske jednadžbe koje opisuju odnos indeksa relativnog sadržaja klorofila izmjerenoga pomoću klorofilmetra i stvarne koncentracije fotosintetskih pigmenata (utvrđene laboratorijski) pred sam kraj vegetacijskog razdoblja. Jednadžbe su konstruirane posebno za kontrolni, a posebno za sušni tretman. S obzirom na takav dizajn pokusa i vrijeme uzorkovanja, primarni cilj rada bio je ispitati utjecaj dugotrajnog sušnog razdoblja na homogenost parametara kalibracijskih jednadžbi (Y-odsječaka i nagiba pravaca). Na temelju dobivenih rezultata zaključeno je da parametri kalibracijskih jednadžbi nisu bili utjecani sušnim tretmanom. Prema tome, rezultati istraživanja ukazuju na to da klorofilmetar CCM-200, uz primjenu odgovarjućih kalibracijskih jednadžbi, predstavlja pouzdan alat za nedestruktivnu procjenu koncentracije ukupnih klorofila i karotenoida u lišću hrasta lužnjaka, bez obzira na različite režime vlažnosti tla kojima je biljni materijal bio izložen tijekom vegetacijskog razdoblja. Uz to, u radu je utvrđeno da bi preciznost procjene stvarne koncentracije fotosintetskih pigmenata bilo moguće i dodatno poboljšati korekcijom klorofilnog indeksa sa specifičnom lisnom masom.The concentration of photosynthetic pigments (chlorophylls and carotenoids) in leaves of forest trees is a good indicator of the photosynthetic efficiency, level of nutrition with nitrogen and autumn leaf senescence. Thus the photosynthetic pigment concentrations is one of the most significant parameters related to the physiological status of plant. Change in pigment concentrations of leaves indicate presence of environmental stress. Well-timed detection of environmental stress play a crucial role in preventing damage on seedlings and saplings in forest nurseries and wood mass production in forest cultures and plantations. Traditional methods for determining the concentrations of photosynthetic pigments represent an obstacle to continuous monitoring concentrations of photosynthetic pigment in leaves of forest trees, primarily because they are relatively expensive, long lasting and require destruction of plant material. However, portable optical chlorophyll meters such as CCM-200 (Opti-Sciences, Tyngsboro, Massachusetts, USA) and SPAD-502 (Minolta Camera Co., Osaka, Japan) is a reliable alternative to traditional laboratory methods. To use chlorophyll meters as a tool for estimating photosynthetic pigment concentrations in leaves, it is necessary to construct regression equations (calibration equations) that reliably describe the relationships between the relative index of the total chlorophyll content in leaves (CCI) and the total pigment concentrations in leaves, determined by standard laboratory methods. In the present study, we set up experiment to establish the ability of the hand-held CCM-200 chlorophyll meter to accurately estimate the content of the photosynthetic pigments in leaves of Quercus robur L. with contrast level of soil moisture. The objectives of the present work were: (i) determine whether the long-lasting drought period significantly influences the relationship between the CCI obtined by CCM-200 and the concentration of photosynthetic pigments (total chlorophyll and carotenoid); (ii) construct calibration equations for non-destructive estimation of photosynthetic pigments in Q. robur leaves; (iii) to analyse the improvement estimation of photosynthetic pigments concentration when CCI was corrected with specific leaf mass. The research was carried out during the year 2015 on 60 two-years old plants grown in the greenhouse located in the Croatian Forestry Institute Jastrebarsko. Plant material was grown in 50 liter containers previously filled with soil originating from a natural oak stand. In the spring of the 2015, at the beginning of the study the mean height of investigated plants was 23.9 ± 4.8 cm. During the study, plant material was exposure to different level of soil moisture. In control treatment soil water content was kept above field capacity, while in drought treatment plants were exposed to water reduction during 112 days (1st of April – 21st of July). In second part of growing season (22nd of July – 22nd of October) in both treatments soil water content was kept above field capacity (Figure 1). Calibration equations, that describe relationship between relative chlorophyll content index measured with chlorophyll meter and actual photosynthetic pigment concentrations in sampled leaves (laboratory determined) at the end of growing season (27th of October), were constructed for both treatments (Table 2 and 3; Figure 4 and 5). Obtined results show that parameters of calibration equations were not affected by drought treatment (Table 4). Therefore, when using appropriate calibration equations, clorophyll meter CCM-200 can be considered as reliable tool for non-destructive estimation of total chlorophylls and carotenoids in Q. robur leaves, regardless of different soil water regimes during the growing season. Additionaly, this research confirmed that it is possible to improve the estimation of actual photosynthetic pigment concentration by using chlorophyll content index corrected with specific leaf mass (Table 2 and 3; Figure 4 and 5)

Quality assessment of high density digital surface model over different land cover classes

Background and Purpose: Recent research on generation of digital surface models (DSMs) using image matching methods revealed a great potential of DSM application in forestry, especially in forest inventory. However, research dealing with DSM generation from digital aerial images are still lacking in Croatia. Therefore, the main objective of this study was to present the workflow for generating high density DSM from colour infrared (CIR) digital stereo aerial images using area-based image matching algorithm. Materials and Methods: The high density DSM was generated from colour infrared digital aerial stereo images using Dense DTM algorithm of PHOTOMOD software - an area-based image matching algorithm which operates on the principle of cross-correlation approach. To evaluate the quality of the generated DSM, an agreement assessment with manual stereo measurements was conducted over three different land cover classes (forests, shrubs, grasslands) using the same images as for DSM generation. Results: The good vertical agreement between the generated DSM and stereo measurement was achieved for all three land cover classes present at the research area. The highest vertical agreement was obtained for the grassland land cover class (RMSE=0.36), slightly lower for forest (RMSE=0.62), whereas the lowest vertical agreement was obtained for shrub land cover class (RMSE=0.83). Conclusions: The results of this research are very promising and suggest that the high density DSM generated from digital aerial stereo images and by using the proposed methodology has the potential to be used in forestry, primarily in forest inventory. Therefore, further research should be focused on generation of CHM by subtracting available DTM from the high density DSM and on the examination of its potential for deriving various forest attributes