The assessment of students' understanding of the difficulty levels in physics, provided by Rasch analysis, is carried out here using two different tests as measurement tools. We used a poly tomous version of the standard FCI test by select ing items that maintain the core of this concep tual inventory. To do this, we randomly divided the 380 responses collected during a recent FCI analysis into five groups and then restructured six items into six separate evaluation scale items. At this stage, we carefully selected items to high light the dominance of one common-sense error in mechanics. Next, we created our own test with items designed to cover six levels of difficulty, al ternating simpler calculation steps within phys ics-based problems. For both cases, the threshold parameter was estimated using the polytomous Rasch model. The results were analysed and dis cussed.

The teaching of climate and environmental issues to undergraduate students in our education system and usually elsewhere is primarily oriented towards educating them with responsibility and care for nature and therefore, the corresponding knowledge is offered through several subjects mostly as supplementary or illustrative acquaintance. These specifics impose changes in the corresponding learning structure compared to fundamental subjects such as physics, mathematics, etc., inflicting additional complexity on studying and measuring it. This work was initiated as an assessment of the level of knowledge of students on climate, environment and earth sciences within the framework of the 2024 National Conference on Climate and Environment of the Department of Physics, and then is expanded into a comparative analysis of the structure of learning and acquisition of knowledge which are offered through distributed sources, with those presented by structured and fundamental disciplines In this regard, this work also aims to evoke some methodologies for measuring the level of students’ knowledge in general and identifying problems in the learning and teaching process. This analytical assessment was carried out through the CI Knowledge Inventory technique, index theory and the Rasch model.

The effect of informal economy on the behavior of exchange rate is complex and difficult to evaluate in common economic conditions. But if informal sector is sizeable and a certain foreign currency is used for transactions therein without being converted, the supply and the demand for this currency, the velocity of the money circulation, and several other variables would be impacted, implicating a measurable response in the corresponding FX rates’ behavior, while the other currencies’ prices will be less affected. Consequently, distinguishable dissimilarities regarding dynamics and statistical features are expected for the exchange rates of the currencies traded in the country. By evidencing and analyzing them, we can proceed with a backward analysis to identify the hidden relationships between informal economy and exchange rates. As a case study we analyzed the FX rates of main currencies traded in Albania, considering that specifically the Euro is used at a non-neglected volume as national currency substitute in the informal sector. Recognizing the complexity of the relationship under investigation, we have employed an interdisciplinary approach by incorporating econometrics and econophysics approaches. After examining the multifractal features of each FX series, the non-stationarity measure for distributions of the corresponding rate of returns, and the significance of self-organizing regimes on FX time series, we noticed that the price of the EU currency behaves distinguishably different. We described the specific features observed for the Euro-ALL exchange rates as an indication of their response to the informal economy and partial usage of the Euro in the role of national currency in this sector. Those findings are used also for opinionizing regarding formalization issues and scenarios of replacement of national currency by the Euro. Acknowledging that informality is undoubtedly harmful for the economy, this work is limited to providing an alternative explanation of specific FX rates comportment observed in the country, and to offer a descriptive analysis for similar systems.

The assessment of the effect of the informal use of a foreign currency on the corresponding FX rates toward the national currency is a very difficult task, requiring direct calculation and modeling. It comes mostly because of the unknown quantity of foreign money used in the informal sector, but also because of the lack of quantitative calculation models. To overcome this gap and to realize a qualitative description of this effect in a concrete economic environment, we propose herein a comparative analysis between the behavior of two typical FX rate series recorded in the Albanian currency market, the Euro-ALL and USD-ALL, providing that the Euro is used commonly as a national currency substitute in the informal economy and the USD is not. So, we have evidenced that the un-stationarity degree of the Bid and Ask spread distribution for the Euro-ALL FX series is higher than for the corresponding USD-ALL case, but with a lower variance. Those features occurring simultaneously can be explained by assuming that informal use of the Euro acts as an additional perturbation on the FX system, imposing high nonstationary, but at the same time it provides reservoir or source features for the money disbalances, reducing the average fluctuations. Next, the depth of the market measured by the average Bid-Ask Spread has resulted in a smaller price for the Euro currency, indicating a lower cost of the transactions and reinforcing the assumption regarding the distribution’s in-stationarity features. Based on those indicatory findings, we propose to realize indirect evidence for our assumptions by comparing the reproduction of the corresponding distribution using autoregressive models. In this case, we have evidenced that the distribution of the FX Euro-ALL spread can be reproduced better if we include in standard ARCHX (m, n, p) models a term that mimics the informality measure. When applying the same procedure for the USD-ALL spread, the resulting distribution has not matched equally well with the original ones. Those findings have been discussed in the framework of an alternative description of the effect of the informal use of foreign currency in a small economy with a sizeable informal sector, which convene our current system under analysis, but we believe that they can be applicable for similar economic environments. Doi: 10.28991/HEF-2024-05-01-02 Full Text: PDF

Since the introduction of the Force Concept Inventory (FCI) in 1992, the CI tests have been widely used for measuring conceptual knowledge and for studying teaching issues in almost all disciplines and levels of study. A standard concept inventory analysis includes the design of a qualitative test, adequate realization of testing, calibration procedure, and comprehensive analysis of its findings. Usually, the CI test calibration is carried out through the Rasch sociometric technique, which is also used for calculating crucial indicators of knowledge such as item difficulties, students’ abilities, and many more. Whereas the quality of the tests’ design can be guaranteed by using certified and professional CI tests, the statistical adequacy of the testing merits critical attention before going on to the final step of the analysis. Also, the analysis of CI outcomes can be advanced by contemplating auxiliary tools and complementary techniques. In this framework, we propose to enforce the test index validity requirement for qualifying the CI outcomes as local or global. Specifically, the conclusions of CI analysis are acceptable for the whole population from which the sample has been extracted if the test's indexes comply with the validity requirements provided by the index theory. In the case when test indexes are out of validity range and re-conducting them is impractical for some objective circumstances or research specifics, we suggest injecting some new records into the existing one or mixing the data gathered from different samples until the new indexes are in the desired range. Using this methodology, we have reviewed our previous FCI tests, which were initially intended to demonstrate the impairment of learning in the physics discipline triggered by online learning during the pandemic closure. Through this renormalization procedure, we obtained a credible assessment of the understanding of mechanics and electromagnetism in high school students who followed online lectures during the pandemic closure. Also, by using indexes’ validity as an auxiliary tool, we identified that for measuring the knowledge of electromagnetism in students enrolled in branches where physics is a basic discipline, a shortened version of the BEMA test was a better instrument than the corresponding shortened EMCI test. Next, we used the optimal histogram idea borrowed from distribution fitting procedures to identify the natural levels of students’ abilities for solving a certain CI test. Another intriguing proposal presented in this work consists of combining an ad-hoc Likert scale assignment for usual errors in physics exams with the FCI designation of the basic commonsense confusion in mechanics for identifying their pairing features in common exams. We believe that the methods proposed herein can improve CI analysis in more general senses. Doi: 10.28991/HEF-2023-04-01-08 Full Text: PDF

In this work, we have analyzed the presence of pharmaceutical compounds in the wastewater of a regional hospital in Vlora, Albania, during June 2020 and June 2021. For this analysis, we measured the concentration of 19 preselected pharmaceutical molecules in discharging water by direct sampling in the waters, and we investigated the presence of pharmaceuticals in the algae Ulva Lactuca. Chemical analysis has been conducted via liquid chromatography in tandem with mass spectrometry at a limit of quantization of 0.1 ng/L. It resulted that, from the ensemble of 19 pharmaceutical molecules consisting of antibiotics, analgesics, psychiatric drugs, and beta-blockers, the antibiotics were found at the highest concentration. The quantity of medical chemicals’ presence varies from 0.2 to 0.24 mg/L. Traces of pharmaceuticals are obtained from Ulva Lactucaalgae in effluent water next to the city treatment plant. The concentration for each of the 19 molecules considered in this work remains below 0.1 ng/L. Finally, the values of physicochemical parameters were found within the range reported by several studies for hospital influent waters, collected in different countries and for many years. Doi: 10.28991/HEF-2023-04-03-03 Full Text: PDF

This research aims to investigate the morphological characteristics, chemical composition and possible sources of aerosol particles. Aerosol samples of the urban atmosphere were examined in the city of Vlora, located in the south of Albania. Scanning electron microscope JEOL JSM-563 equipped with an Oxford Link ISIS L300 for energy-dispersive X-ray [EDS] analysis was used to examine aerosol particles. In addition, images of aerosol particles were processed by ImageJ software for dimensional and morphological analyses. The primary data automatically generated by ImageJ were surface, perimeter, minimal and maximal size, circularity, and aspect ratio parameters. Then, the projected area diameter, volume equivalent diameter (dev), physical diameter, and aerodynamic diameter were calculated. Based on the results of particle morphology and chemical composition nine groups of aerosol particles were classified: aluminosilicates (fly ash and soil particles), Ca-rich particles, carbon particles (soot particles and biogenic particles), sea salt particles, Si-rich particles, Fe -rich particles, and mixed particles. The morphological analysis results indicated that aerosol particles were relatively distributed over a wide size range of 0.5 mu m to 28 mu m fitted to lognormal distributions. In the measured distributions a peak around 2 mu m is dominant. By accounting for volume equivalent and diameter aerodynamic shape factor, this study develops the method of the aerodynamic diameter calculation.

Abstract In this work we have studied the spreading of militantism in 1D and 2D square lattice by operating the q-XY opinion and its utility optimization as control mechanism for the update process. The average utility and opinion value for a pair of opinion nodes are calculated in the framework of standard statistical mechanics using the q-opinion utility U = − J 2 ( O → 2 − 2 ) − F O → + q ( J 2 ( O → 2 − 2 ) ∗ F O → ) . The agreement with an incoming zealot opinion is modelled as one by one dialogue starting from a random opinion configuration. Each time step one node updates its opinion value according to a set of rules and by specific probabilities based on local utility improvement. New opinion values are accepted with a Metropolis-like probability calculated by employing q-utilities of the nodes under updating process. For the chain opinion structure in the interaction type preserving regimes where 1 − q J 2 ( O → 2 − 2 ) > 0 given 0 ≤ O ≤ 1 it resulted that that both 1D and 2D structures accept the militant offer only partially. For bounded chain the agreement level is at average values for short chain and low values for bounded long opinion chain. Bounded chain structures are found resistant toward militantism accommodation. For square opinion lattices we obtained also that the militant attitude would never cover all the community. Homogenous-nodes group resulted somewhat deterring in accepting the militant opinion with an agreement level of around 0.6. For heterogonous communities the edge agreement level closed up to around 0.7-0.8. The model reproduces the fact that there would be always a fraction of opposition whatsoever regime is applied. It produces various outcomes imitating the complexity of the social behaviour.

The topology of a biological network may differ, depending on the type of elements and the interactions between them. A protein signaling pathway considered as a directed network can be studied through the centralities analysis. The knowledge about the centralities is crucial to determine the most important network nodes, which can somehow define the further analysis needed for that network. Here we make a structural analysis of two networks, the AMPK-signaling pathway, and the mTOR-signaling pathway. The commonalities between these two networks are visible, and calculation of the centralities for all the nodes of the two networks show that they both have the same most important nodes, meaning that the signal inside the networks passes mostly through the same most important proteins such as AMPK, mTOR, RHEB, Akt, ELK1.2, and TSC1/2. However, we aim to go beyond this process. Our purpose is to make a dynamic study of a new bigger network composed of the most important nodes of these two elementary nodes. In this way, we can better predict all these vital proteins' effects on other elements, inside or outside the network.

Log-periodic (LP) functions of the general form y = y 0 + A ( t − t c ) m (1 + Bcos( ω ∗ log( t − t c ) + ϕ 1 )) have been demonstrated effective in the analysis of the processes characterized by the discrete scale of invariance (DSI) structure and also self-organization behaviour. If other self-organization processes opposing or supporting the principal activity would be present, a multilevel DSI structure is expected to develop and the resulting dynamics would depart from the log-periodic shape. When discussing the processes characterising the daily new positive records for the COVID-19 cases in the country (Albania) we have identified the elements that are responsible to generate modified LP behaviour. The new records that initially represented simply the findings of the state laboratories, are modified each successive days by the pressure for more tests form anxious individuals and other effects which produce a herding behaviour which emergence a LP dynamics. Meanwhile, the reactive behaviour aiming to oppose undesired occurrence would generate additional LP sub-processes that can be trapped by a modified LP function of the form y = y 0 + A ( t − t c ) m + B ( t − t c ) m cos ( ω ∗ log( t − t c ) + ϕ 1 ) + C cos ( ( ω − ω 1 ) log( t − t c ) + ϕ 2 )+ D ( t − t c ) m cos (( ω + ω 1 ) log( t − t c ) + ϕ 3 ). During the period of the self-organization behaviour the process is highly nonlinear and therefore the classical models (SIR) based on the mean field assumption and the corresponding ODE equations are not effective to represent the system dynamics. In our case the LP fit to the Covid-19 new cases data series, has challenged the ODE models for the time interval of initial appearance of the positive cases in the country (as of 2 March 2020) up to 3 month later. Also, the LP function has predicated the multiphase waving behaviour and we have forecasted two peak, each of them weeks before recurrence, respectively at 28 April and 10-12 June. Those peaks have been confirmed later within 2 days uncertainty. It resulted that the first regime have been succeeded by another new self-organization regime due to drastic condition changes as result of the socio-economic opening which started in the end of the May 2020. As result, the new regime is juxtaposed over the old one and the LP dynamics remained characteristic and another critical time has appeared. The new critical time has been reproduced with good certainty (1 August) and also the magnitude of the new cases. We observed that our empirical LP function is effective in the describing long term dynamics whereas local techniques involving neural networks approaches have reproduced very well the new cases after the first regime. We concluded that after identification of the LP regimes, we can adopt successfully short time forecasting for new occurrence when working away from the critical time identified by the first method.

In this work we study the system of the votes, the mechanism of the electoral support formation, and also the elements of its dynamics, by analyzing the data from several election processes in Albania. Firstly, we evidence the specific features and the characteristics of the distributions of votes through a descriptive approach, and next we use those findings to identify the nature of the elementary processes of the agreement, the defects of the system and dynamical issues. The distributions of the votes for the majority or majority-like election as by polling stations reference results a two-parts function. The part of the distribution located in the small vote fraction fits to a power law or to a q-exponential function, therefore the foremost factor of the electoral support for the subjects populating this zone is based in the preferential attachment rule, with some modification. Consequently, the small subjects or independent candidates, realize their electoral attractiveness based on the individual performance. Also, their voters act rationally and usually gather sufficient information before deciding to support them. The bell-shaped part of the distribution which describes the votes of the candidates of the main parties, fits better to the q-gaussian functions. In this case, electoral support is affected strongly by the political activists (militants) which harvest local influences to convict people producing an extra support for the candidates of big parties, regardless of their performance and electoral values. This physiognomy is characteristic for all legislative and administrative majority voting or other majority-like elections as practically behave the closed-lists elections of 2009, 2013, 2017 and also the semi-opened list of the 2021. The distributions of the closed-list votes in the administrative elections are mostly of the exponential or q-exponential type. Also, the distributions based on the data from electoral constituencies which include many polling stations resulted q-exponentials for all types of elections. We connected the q-exponential form of the distribution with the electoral network failures, system deficiencies and heterogeneity effects. In 2021, the distributions of the votes for subjects is obtained similar to the typical recent majority voting distribution, a mix of the power law and q-gaussian functions. The distribution of the votes for the candidates on the semi-open list for those elections resulted a mix of two q-exponentials. We associated this last with the difficulties of the voters to understand new electoral rules and additional other causes of the non-electoral nature. Also, the electorate network might have suffered extra irregularity issues due to the inadequate sizes of elections units, etc. The distributions of the votes for the two main parties are found q-gaussians with q ∼ 1.32 and q ∼ 1.57 for the right and the left wing respectively. Based on the non-stationarity level measured by the q-value, significant redistribution events are expected for the left-wing network, whereas the right-wing network would experience fewer changes in ceteris paribus socio-electoral conditions. Interestingly, the mix of the votes for two main political parties has produced a q-gaussian with q=1.004, and subsequently, the joint system is found in a more relaxed state. Therefore, the compound network including two main parties is likely to not undergo significant redistribution of the votes in the near future. This means that the small subjects or the fresh-born ones are not likely to cause changes on the system. Based on the deductions for electoral agreement formation, we used our recently introduced q-opinion approach to model the electoral opinion formation. In this model, the q-opinion produces an additional term that multiplies the modified preferential attachment probability for the link establishment. Herein, the q-parameter is calculated by using an ad-hoc formula involving the performance of the candidate as utility function, which associates the agreement behavior as the response, with the candidate performance as the offer or the cause factor. The quantity q henceforth acts as activation-inhibition switch of the extra utility involved in the q-opinion model, and particularly it provides a nonzero voter’s support for the high-performance opponent candidates. The model has reproduced the distributions analyzed in this study. It resulted that many voters in this electorate system act rationally, despite their affiliations.

The geomagnetic field is among the most striking features of the Earth. By far the most important ingredient of it is generate in the fluid conductive outer core and it is known as the main field. It is characterized by a strong dipolar component as measured on the Earth’s surface. It is well established the fact that the dipolar component has reversed polarity many times, a phenomenon dubbed as dipolar field reversal (DFR). There have been proposed numerous models focused on describing the statistical features of the occurrence of such phenomena. One of them is the domino model, a simple toy model that despite its simplicity displays a very rich dynamic. This model incorporates several aspects of the outer core dynamics like the effect of rotation of Earth, the appearance of convective columns which create their own magnetic field, etc. In this paper we analyse the phase space of parameters of the model and identify several regimes. The two main regimes are the polarity changing one and the regime where the polarity remains the same. Also, we draw some scaling laws that characterize the relationship between the parameters and the mean time between reversals ( mtr ), the main output of the model.

In this article, we discuss general properties of the q-opinion model which is based on the extension of the XY magnet model. After considering a short briefing of our recently introduced q-XY model and providing the general statistical mechanics calculation for it, we analyzed specifics and application for the of the 2-node chain. The model is capable to interpret some particular features of the opinion in a couple including shifting behavior, losing interest on a given issue for specific opinion microstates etc. We proposed to use this model in a manded version of the preferential attachment rule for link establishment in a social network. Doi: 10.28991/HEF-2020-01-02-05 Full Text: PDF

The descriptive analysis for the very long-term behavior of the Euro/ALL exchange rates has identified a near to average .revert behavior which contradict some econometric arguments and economical level of the country. Apparent anxious regimes have continuously ended up without crashing and generally the national currency of the not competitive economy has shown a nearly stabilized dynamics toward EU currency. Some of those properties have been explained herein by employing the analysis of the system from complexity and econo-physics point of view. So, by approaching the trend we obtained that the time precursor is characterized by local self-organization regimes that never organized in long scale to produce dangerous move. Thermodynamic–like processes have acted constantly as stabilizer of the national currency value. More details and features have been considered by analyzing the distributions and multifractal structure of the series in the framework of the non-equilibrium statistical mechanics approach. Gathering the information about the stationarity of the states, presences of regimes and their properties, we realized to identify the optimal condition for measurement, modeling and steadfast descriptive statistics. Finally, by using neural network we have realized a forecasting example for one month time interval. The work aims to reveal the importance of interdisciplinary consideration for better results in the study of complex socioeconomic systems.

The presence of heavy metals in the maritime waters has been constantly considered as an important issue in the environmental aspects. In this framework, herein we report some findings from measurements of concentration of so called heavy metals in the sea waters of the Vlora (Albania). We obtained that the concentrations of Cu. Fe, Cd, Mn, are in the range of their average values in other Adriatic places. Usually the concentration of those elements depends on the positions where measurement have been made, indicating that isolated sources of pollution are likely to present. We observe a slight decrease of the construction of Cu and Mn following maritime local flows. Next we obtain that the concentration of Cu. Cd. Fe, Mn, Ni in the near coast line stabilize below 1m of depth supporting the idea that the sediments or the floor of the sea coast are not source and major factors of pollution with those elements are atmospheric process, water discharges and seawater flows.

In this paper we present some thematic aspects related to the study of informal sector in the Republic of North Macedonia for the period [1998, 2016]. So, by conventional application of CDA model we perceived problematic issues in the estimation of the informal economy. To recover the model aftermaths, we assisted the calculation procedures by additional descriptive analysis aimed on avoiding the regression disturbances from critical dynamics. By evidencing the presence of self-organization regimes in some money-type variables, we identified the intervals where data series behaved highly nonlinearly. Consequently, by excluding parts of series up to a reasonable point (herein before 2004), the CDA predictions for the size of informal economy and the relationship with its factors has been improved remarkably. Next, we used factorial analysis to facilitate the design of the n-p-m MIMIC model. This investigation applied in 22 candidate factors suggested the configuration 9-2-3 as optimal structure for the model. In particular this model anticipated two terms confined in the latent variable structure, respectively in the range [0.35, 0.38] and [0.023, 0.08] part of the GDP. We assigned them as subparts of informal economy reflecting differenced influences or weights of certain cause factors. We observed that the estimated effect of the factors included in the model followed theoretical expectation.