Basic Variables Research Articles

Generalized photo-thermo-microstretch elastic solid semiconductor medium due to the excitation process

A novel model in the photo-thermoelasticity theory with microstretch properties is studied. The plasma-elastic-thermal plane waves are propagated in a linear isotropic generalized photo-thermo-microstretch elastic semiconductor solid medium. The photothermal excitation occurs in the context of the microinertia of the microelement process during two-dimensional (2D) deformation. The harmonic wave techniques are used to get the solutions for the basic variables. The analytical solution of the main physical fields; carrier intensity, normal displacement components, temperature, stress load force, microstress and tangential coupled stress can be obtained. Some graphics illustrated when using the plasma, thermal and mechanical load boundary conditions are applied at the outer free surface of the elastic medium. Some semiconductor materials, as silicon (Si) and Germanium (Ge), are used to make the numerical simulation and some comparisons in different thermal memories are made. The main physical variables with new parameters are discussed theoretically and shown graphically.

The impact of relations with stakeholders on change management, innovation and competitiveness of the organization on the example of the current economic situation of enterprises in Poland

Purpose: The purpose of this article is to systematize knowledge about organizations' relationships with their stakeholders and to highlight the connection and impact that managing these relationships and functioning in their network can have on them: an organization's capacity for innovation, change management efficiency and competitive advantage. Design/methodology/approach: Approach to the subject of the paper is theoretical in its first part and in the second one is based on the case study methodology conducted in chosen organization in Poland. On the basis of the literature, the basic variables influencing the accumulation of effects that can be achieved by an organization that effectively uses the synergy of all mentioned phenomena have been analysed. The examples of organizations in Poland applying such activities in the current economic situation were cited. Findings: Organisations which deal with difficult market situation should flexibly: use support from their stakeholders, take the risk of innovation and using both of the above try to implement and manage necessary changes efficiently and quickly. All these phenomena as well as the way of dealing with them make coping with hard situation easier. Practical implications: Article’s analysis and general view confirmes the significant economic and business impact on maintaining and increasing the competitive advantage of organizations using all mentioned phenomena to deal with difficulties of global market. Mentioned positive practical effects on enterprises prove how high the potential is created as a result of combining management of relations with stakeholders on competitiveness, innovation and the ability to manage organizational change. Originality/value: The interactions and effects of the impact on the organization of: stakeholders relations, networks and change management – that have already been scientifically described many times were emphasized because only in a few sectors of the economy their’ coexistence and its effects on the organization are clearly visible, observable and possible to describe.

Evaluation of the INM RAS climate model skill in climate indices and stratospheric anomalies on seasonal timescale

The study of winter seasonal predictability with the climate model INM-CM5-0 is presented. Initial conditions were produced using ERA-Interim reanalysis data for atmosphere, SODA3.4.2 reanalysis data for ocean and the bias-correction algorithm. The seasonal 5-month re-forecasts consisting of 10 ensemble members with small initial condition perturbations for each year over the 35-yr period are conducted. A comparison of the multiyear mean winter averaged anomaly correlation for basic variables in several regions with similar results of SLAV model was conducted. An increase in the anomaly correlation for the years with El Niño and La Niña events was shown. The predictability of NAO and PNA indices was studied. INM-CM5-0 provides very high skill in predicting the winter NAO (correlation coefficient of 0.71 with ERA-Interim reanalysis and 0.68 with instrumental CRU data for 1991–2010). It was shown, that the stratospheric variability provides a significant contribution, although potentially is not the only cause of model high skill in NAO index predictability. Correlation coefficients for PNA index in December-February is 0.60. In the years of the most pronounced El Niño the values of PNA index have significantly positive values, and for La Niña years they are noticeably less than zero.

A Study on Alternative Foam Agents for Model Approval Test of Foam Extinguishing System

In this study, the performance of foam agents and test foam is compared and analyzed through experiments. The line proportioner method is used to release the foam agents at a mixing ratio of 1% and 3%. The inlet/outlet circumference of the proportioner is 40 A, and foam regulators are used at 1% and 3%, respectively. The basic variables such as flow rate, pressure, and measurement time are maintained at 200 LPM, 350 kPa, and 60 s, and the change in the mixing ratio is analyzed in the order of water, alcohol foam, and test foam. The experimental data processing method is carried out in accordance with the regulations of Korea Fire Institute (KFI). In the case of the test foam 1% mixing experiment, the performance is certified because the average emission mixing ratio is 1.19%, which is within the range of 1~1.3%. In the case of the test foam 3% mixing experiment, the average emission mixing ratio is 3.05%, which is within the range of 3~3.9%.

A Panel Analysis of Trade Gravity between Pakistan and South Asian Countries

This paper attempts to examine Pakistan’s trade patterns with South Asian countries by using a gravity model of trade. The main objective of the study is to quantify the long‑run impacts of gravity variables. To achieve this objective, a panel data set for the period 2003 to 2017 has been used. Based on the mixed evidence of the results of panel unit root tests, Pooled Mean Group (PMG) and Panel Dynamic Ordinary Least Square (DOLS) techniques are applied. The outcome of the PMG and Panel DOLS models justifies the theoretical background of the gravity model and suggests that all the basic gravity variables haveusual signs. The RGDPs and population of both Pakistan and the partner country have a positive impact on their bilateral trade. On the other hand, the distance between the two trading countries and the exchange rate have a negative impact on bilateral trade.The uniqueness of this study is that it measures the impacts of qualitative variables along with basic gravity variables. Language similarities and common borders have a positive impact on bilateral trade. Pakistan has borders with India and Afghanistan, but their trade relations are not worth mentioning. The military conflicts between Pakistan and India, and the political suspicions between Pakistan and Afghanistan hinder their trade relations.

An attempt to realize the role of the receiver's awareness in limiting the influence of television

This research deals with a topic related to the recipient, which is considered by some of the most important people involved in media affairs, the structural engine of the media action and its structural goal, i.e. for this act, through the role played by the awareness that it possesses in limiting the effect that television intends to create in its human entity through its formative dimensions The basic of his cognitive, psychological and physical responses. From here, the research aims to: Ensure the importance of the recipient in the communication process and its actual role in it. Disclosure of the role of awareness in achieving influence in the Communi- cation process. Ensure that there is a relationship between awareness levels and the intensity of the impact of television. This research is considered descriptive research that is appropriate to understand the details of its basic variables and the interrelationships that provide us with what is happening in its space charged with reciprocal influence shipments, using the survey method through the survey interview tool, relying on two societal segments that are far apart in terms of their level of education, a research community, and from them, (40) male and female respondents were chosen, in equal proportion, between them.

Acceptance of Technology in Online Learning Perspective at Educational Institutions : A Systematic Literature Review

Today, many applications or technologies have been produced by every software developer. However, the success of all there is the decision of each user. Users have two possibilities to accept or reject a technology that is presented. The TAM model has been widely researched and undergone development and changes besides being quite reliable in predicting the level of technology acceptance in all countries in the world. In this study, we will recapitulate all studies on the acceptance of technology in the field of Education that handles online learning. The results showed that there was 51 article review publication were selected through some process of review. The period taken ranges from 2011 to 2020. The main findings show that there are differences in the models, methods, and applications identified. Since the TAM model has two basic variables, namely perceived ease of use and perceived usefulness as a framework for analyzing the make and influence technology acceptance. In this study also provides information about the results of the identification of some of the gaps in current research and also in the future. Therefore, the results of a systematic literature review were able to provide a better understanding of TAM especially in the perspective of education in online learning.

A Hybrid Method for Traffic Incident Detection Using Random Forest-Recursive Feature Elimination and Long Short-Term Memory Network With Bayesian Optimization Algorithm

Automatic Incident Detection (AID) is an important part of Intelligent Transportation Systems (ITS). A hybrid AID method using Random Forest-Recursive Feature Elimination (RF-RFE) algorithm and Long-Short Term Memory (LSTM) network optimized by Bayesian Optimization Algorithm (BOA) is proposed in this article. Firstly, a relatively comprehensive set of initial variables is constructed using basic traffic variables and their combinations. Secondly, feature variables are selected from the initial variables using the RF-RFE algorithm. Then, the feature variables are used for training the LSTM network, and the hyper-parameters of the LSTM network are optimized by BOA. In addition, Synthetic Minority Over-Sampling Technique (SMOTE) is employed to solve the problem of imbalance between incident sample size and non-incident sample size. Finally, experiments are conducted using real-world data to test performance of the proposed method and compare with several state-of-the-art AID methods on multiple evaluation criteria. The experimental results illustrate that the proposed method achieved superior performance with respect to almost all the evaluation criteria. It also shows that the proposed method is promising for dealing with the problems of imbalance and small sample size of traffic incident data.

SOCIAL OFFICIAL FOR YOUTH IN THE FACE OF RUMORS A COMPARATIVE STUDY IN DIFFERENT SETTINGS

The current study aims to reveal the social responsibility of young people in the face of rumors and the interest in responding to what was published on Facebook, and the researchers identified a sample of (308) from rural and urban areas in the age stages of (18:30). The researchers used the descriptive approach and applied the scale form. The sample of the study in rural and urban areas was also processed using (T) test, correlation factor, Ca2 coefficient, arithmetic mean, standard deviation, weighted percentage mean, numbers and percentages for all scale questions, Older youth are less likely to use the Internet than younger youth (18-30), as it was found that they use Facebook by 80% and make sure that the difference in usage may be affected by age, education, and income, as for gender and origin has no effect, The study also proved that there is no statistically significant relationship between some basic variables and the total scale as a variable. Study recommendations: 1- There must be awareness programs, as many Facebook users have become victims of breaches 2- Legislation must be enacted to control those who spread rumors on Facebook 3- Optimizing the energy and strength of youth, refining them with knowledge and training experiences, and utilizing free time

Emerging behaviours from cyclical, incremental and uniform movements of hyper-redundant and growing robots

The purpose of this work consists of finding a simple and general method to control hyper-redundant manipulators. By definition, hyper-redundant robots have a large number of degrees of freedom which makes it difficult to find fast and stable solutions. In the case of growing robots, where the number of degrees of freedom can even increase, the problem is exacerbated. This work proposes a new approach. By modifying and reinterpreting the three basic variables needed for operation in a three-dimensional space, our framework gives rise to a number of novel, decentralized control behaviours. These behaviours were not designed but rather emerged as a result of cyclical, incremental and uniform movements in the robot body. They include different modes of attraction, repulsion, surrounding, straightening, folding and circumnutations. As opposed to traditional control approaches which are typically programmed for one specific application, this framework provides a set of general behaviours that can be combined using different motion strategies for a wide number of applications. We demonstrate the usefulness of this approach in a number of scenarios for hyper-redundant and growing robots.

A Study of Clinical Profile and Fetomaternal Outcome of Obstetric Patients Admitted to Intensive Care Unit: A Prospective Hospital-based Study

Aims and objectivesTo study clinical profile of obstetric patients admitted to intensive care unit (ICU) and to analyze the relation of demographic factors such as age, parity, literacy level, socioeconomic status, acute physiology and chronic health evaluation II (APACHE II) score, and level of delay with fetomaternal outcome.DesignIt is a prospective cross-sectional observational study.Materials and methodsAfter admission to ICU a detailed history, analysis of basic demographic variables along with level of delay was done. APACHE II score was calculated. These parameters were correlated with fetomaternal outcome. The Chi-squared test was used to compare categorical variables. The one-way analysis of variance was used to compare the continuous variables among the strata with Tukey's post hoc test.ResultsIncidence of obstetric ICU admission was 0.77%. Mean age was 26.03 years. Most common indication of ICU admission was obstetrical hemorrhage (37.1%) followed by hypertensive disorders of pregnancy (25.8%). Type I delay was the most common followed by type II delay. Mean APACHE II score was 14.77 ± 6.85. Observed mortality rate (30.6%) was found to be higher than predicted mortality rate (25%). APACHE II score was significantly high in the presence of level 1 (p = 0.003) and level 2 delays (p = 0.0001). Also, it was significantly increased with the duration of delays.ConclusionUnbooked and referred cases had high incidence of ICU admission. The presence of delay was associated with poor outcome.How to cite this articleMiglani U, Pathak AP, Laul P, Sarangi S, Gandhi S, Miglani S, et al. A Study of Clinical Profile and Fetomaternal Outcome of Obstetric Patients Admitted to Intensive Care Unit: A Prospective Hospital-based Study. Indian J Crit Care Med 2020;24(11):1071–1076.

Loneliness and Purpose in Life Are Important Predictors for Future Care Planning

Experiencing purpose and social connection in later life is associated with better quality of life, better cognition, less morbidity, and lower risk of mortality. People who experience less purpose in life are more likely to report loneliness (Neville et al., 2018), and those with vision impairment are at greater risk for loneliness than the general population (Brunes et al., 2019). Planning for future care may be one way to enhance late life outcomes, but it is unclear how loneliness and purpose in life are related to planning behaviors in older people with vision loss. Using a sample of 200 older adults who were diagnosed with macular degeneration, this study explored the association of loneliness and purpose in life on future care planning variables after controlling for basic health and demographic variables. Hierarchical regressions showed that 1) people who are lonelier (β=.26, p<.05) but report greater purpose in life (β=.19, p<.05) are more aware of future care needs (ΔR2= .14, p<.001); 2) people who are lonelier (β=-.16, p<.05) but report greater purpose in life (β=-.46, p<.001) are less avoidant of planning (ΔR2= .14, p<.001); and 3) people who report greater purpose in life are more likely to gather information (β=.24, p<.05; ΔR2= .04, p<.05) and establish concrete plans related to planning for future care (β=.25, p<.05; ΔR2= .06, p<.001). These results suggest that having purpose in later life may boost planning behaviors, while those who are lonely may need help translating their awareness of future care needs into planning behaviors.

A New Generation of Thermal Energy Benchmarks for University Buildings

In 2008, the Chartered Institution of Building Services Engineers (CIBSE TM46 UC) presented an annual-fixed thermal energy benchmark of 240 kWh/m2/yr for university campus (UC) buildings as an attempt to reduce energy consumption in public buildings. However, the CIBSE TM46 UC benchmark fails to consider the difference between energy demand in warm and cold months, as the thermal performance of buildings largely depends on the ambient temperature. This paper presents a new generation of monthly thermal energy benchmarks (MTEBs) using two computational methods including mixed-use model and converter model, which consider the variations of thermal demand throughout a year. MTEBs were generated using five basic variables, including mixed activities in the typical college buildings, university campus revised benchmark (UCrb), typical operation of heating systems, activities impact, and heating degree days. The results showed that MTEBs vary from 24 kWh/m2/yr in January to one and nearly zero kWh/m2/yr in June and July, respectively. Based on the detailed assessments, a typical college building was defined in terms of the percentage of its component activities. Compared with the 100% estimation error of the TM46 UC benchmark, the maximum 21% error of the developed methodologies is a significant achievement. The R-squared value of 99% confirms the reliability of the new generation of benchmarks.

Soil–vegetation–atmosphere interaction over a hilly forest in the southern Huaihe River Basin: Long-term field experiment and preliminary analysis of basic observations 淮河流域南部丘陵森林地区土壤-植被-大气相互作用:长期野外试验观测的初步分析

To improve the understanding of the CO2 exchange and the cycling of energy and water between the land surface and atmosphere over a typical hilly forest in southeastern China, a long-term field experimental observatory was established in Huainan, Anhui Province. Here, the authors briefly describe the three parts of ongoing research activities: the environmental monitoring at the site, the meteorological observations on a high tower, and particularly the intensive measurement of soil–vegetation–atmosphere interaction on a lower tower. Specifically, the diurnal variation of basic meteorological variables on a typical clear day (13 July 2018), and their temporal variation in the first three months of the low tower's operation (4 June to 31 August 2018), and in combination with simultaneous data from the high tower, are analyzed. Results show that the data demonstrate reasonable variabilities, and the variables exhibit significant diurnal variation, characteristics of summer values, and considerable differences in summer months. The daily and monthly average albedos above the forest canopy were both 0.13. The daily average soil CO2 concentration was 1726 and 4481 ppm at 2 and 10 cm, respectively. The soil CO2 concentration changed with soil volumetric moisture contents, but showed a weak correlation with soil temperature in summer 2018. As the observatory continues to run and data continue to be collated, further investigation of the long-term variation of monsoon characteristics should be performed in the future. The experiment is useful in ecosystem and atmosphere interaction research, as well as for the development and evaluation of climate models, in the transitional climate zone of the Huaihe River basin.摘要本文简要介绍了包括三部分观测的安徽淮南长期野外试验观测站, 特别是土壤-植被-大气的集中观测, 对小塔运行前三个月 (2018年6月至8月) 的数据, 并结合同一时段大塔获得的数据, 进行了初步分析.结果表明这些资料有合理的变化特征, 日变化和夏季值特征显著, 各月份间气象变化有明显差异.土壤水分和温度受降雨影响, 在不同的下垫面条件下表现出不同的变化.土壤CO2日平均浓度在2 cm和10 cm处分别为1726和4481 ppm.2018年夏季土壤CO2浓度随土壤体积含水量的变化而变化, 但与土壤温度呈弱相关.

Design and Testing of Inertial System for Landslide Displacement Distribution Measurement.

Landslide displacement monitoring plays a fundamental role in the study of landslide evolution mechanisms, forecasting, risk assessment, prevention, and control. To fill the deficiencies of traditional instrumentation for measuring landslide displacement distributed along lateral direction, a landslide displacement measurement method based on deformation-coupled pipeline trajectory measurement is proposed, and a pipeline trajectory inertial measurement instrument is developed. The developed instrument, primarily comprised of a single shaft gyro, two axis accelerometers, and an external roller encoder, is designed as an axial half strapdown-radial half platform structure combined with a mechanical gravity platform. This structure avoids the singularity of pitch angle and roll angle and can expediently calculate a pipeline trajectory with an Eulerian transformation when obtaining several basic physical variables, e.g., the axial linear velocity, pitch angle, roll angle, and azimuth angle. Additionally, the pipeline trajectory, measured at different times, possesses the ability to reflect the displacement evolution feature of landslides. The results of prototype simulation tests imply a single measurement accuracy of a 12 cm/100 m span and a singly periodic multiple (more than five times) measurement accuracy of a 3 cm/100 m span, which meets medium-precision displacement measurement requirements for a landslide. Additionally, the finished instrument has been successfully applied to the deformation monitoring of the Majiagou I# landslide, which further verifies its feasibility and offers a reference for similar landslides.

Determinants of customers’ intentions towards environmentally sustainable banking: Testing the structural model

The increasing urbanization and changing consumption patterns are putting great strain on environmental sustainability. The consumption patterns need to be reformed due to the great contribution to rising carbon emissions. The customers are also becoming aware of the various environmental issues. The current research developed and tested a conceptual framework to scrutinize the antecedents of customers' intentions to adopt environmentally sustainable banking services and activities. Following the theory of planned behaviour (TPB), this paper incorporated the constructs namely trust, environmental consciousness, and perceived behavioural outcomes in addition to its basic variables. The data were gathered from a cross-sectional sample of 440 Indian bank customers using a survey method. PLS-based structural equation modelling technique was employed to test the research model. The results indicated that TPB constructs exert significant influence on customers’ behavioural intention. The environmental consciousness was marked as a highly significant predictor of perceived behavioural outcomes which in turn was found to be a significant determinant of trust as well as behavioural intention. Moreover, the attitude was found to be a significant outcome of trust and environmental consciousness. This research puts forth the theoretical as well as managerial implications and provides directions for further research in the concerned thrust area.

Undrained cylindrical cavity expansion in modified cam-clay soil: A semi-analytical solution considering biaxial in-situ stresses

This paper presents a semi-analytical solution for undrained cylindrical cavity expansion in modified Cam-clay soils under biaxial in-situ stresses based on the small strain and large strain assumptions in the elastic and plastic regions, respectively. The cylindrical cavity expansion problem is treated as a boundary value problem and formulated by solving a system of first-order differential equations with four stress components as basic unknown variables. The validity of the proposed solution is examined by comparing with the existing solution, where the in-situ stress is uniform. Extensive parametric studies are conducted to investigate the effects of biaxial in-situ stresses on the stress distribution, the expansion process and the shape and size of elastic-plastic boundary. The results indicate that the elastic-plastic boundary is in the shape of an ellipse due to the shear stress induced by biaxial in-situ stresses. The major axis of the elliptical elastic-plastic boundary is in accordance with the direction of the larger in-situ stress. The present solution is free of the limitation that the cavity expands under the uniform in-situ stress, therefore it is expected to provide a more general method for practical geotechnical and petroleum problems.

Postoperative hypothermia after total aortic arch replacement in acute type A aortic dissection-multivariate analysis and risk identification for postoperative hypothermia occurrence.

BackgroundPostoperative hypothermia (PH) is a common physiological abnormality associated with increased morbidity and mortality after non-cardiac surgery. The incidence, risk factors of PH and its impact on early outcomes after total aortic arch replacement are not clear.MethodsWe conducted a retrospective cohort study in patients with acute type A aortic dissection who underwent total arch replacement from January 2013 to December 2016 at our institution. Basic variables, procedural and postoperative early outcomes were collected. Univariate and multivariate statistical analysis were performed for statistical interpretation. The early outcomes were compared between patients with or without PH.ResultsA total of 300 patients (age 53.8±11.5 years, female 63, 21.0%) with acute type A aortic dissection underwent total arch replacement. Forty-four patients (14.7%) developed PH. The independent risk factors of PH are age and the intraoperative lowest bladder temperature. There is no significant difference in major postoperative morbidity and mortality between patients with or without PH.ConclusionsThe incidence of PH after total arch replacement in acute type A aortic dissection is relatively low. The independent risk factors of PH in this population include age and the intraoperative lowest bladder temperature. With comprehensive rewarming strategy upon arrival at the ICU, the PH is easy to be corrected, and the adverse effect of transient PH on early outcomes after arch surgery is minimal.

The effect of burn mechanism on pediatric mortality in Malawi: A propensity weighted analysis

IntroductionThe burden of global trauma disproportionately affects low- and middle-income countries, with a high incidence in children. Thermal injury represents one of the most severe forms of trauma and is associated with remarkable morbidity and mortality. The predictors of burn mortality have been well described (age, % total body surface area burn [TBSA], and presence of inhalation injury). However, the contribution of the burn mechanism as a predictor of burn mortality is not well delineated. MethodsThis is a retrospective analysis of prospectively collected data, utilizing the Kamuzu Central Hospital (KCH) Burn Surveillance Registry from May 2011 to August 2019. Pediatric patients (≤12 years) with flame and scald burns were included in the study. Basic demographic variables including sex, age, time to presentation, %TBSA, surgical intervention, burn mechanism, and in-hospital mortality outcome was collected. Bivariate analysis comparing demographic, burn characteristics, surgical intervention, and patient outcomes were performed. Standardized estimates were adjusted using inverse-probability of treatment weights (IPTW) to account for confounding. Following weighting, logistic regression modeling was performed to determine the odds of in-hospital mortality based on burn mechanism. ResultsDuring the study period, 2364 patients presented to KCH for burns and included in the database with 1794 (75.9%) pediatric patients. Of these, 488 (27.6%) and 1280 (72.4%) were injured by flame and scald burns, respectively. Males were 47.2% (n = 230) and 59.2% (n = 755) of the flame and scald burn cohorts, respectively (p < 0.001.) Patients presenting with flame burns compared to scald burns were older (4. 7 ± 3.1 vs. 2.7 ± 2.3 years, p < 0.001) with greater %TBSA burns (17.8 [IQR 10–28] vs 12 [IQR 7–20], p < 0.001). Surgery was performed for 42.2% (n = 206) and 19.9% (n = 140) of the flame and scald burn cohorts, respectively (p < 0.001.) Flame burns had a 2.6x greater odds of in-hospital mortality compared to scald burns (p < 0.001) after controlling for sex, %TBSA, age, time to presentation, and surgical status. ConclusionIn this propensity-weighted analysis, we show that burn mechanism, specifically flame burns, resulted in a nearly 3-fold increase in odds of in-hospital mortality compared to scald burns. Our results emphasize flame and scald burns have major differences in the inflammatory response, metabolic profile over time, and outcomes. We may further utilize these differences to develop specialized treatments for each burn mechanism to potentially prevent metabolic dysfunction and improve clinical outcomes.

New generalized height-diameter models for birch in European Russia

Height and diameter at breast height are basic variables that are measured in a forest inventory. Generalized models do not require measuring tree heights or number of measurements is minimal. The purpose of this study was to obtain 24 new generalized height-diameter models based on simple basic models, compare them with 9 generalized models selected from other studies, and develop an appropriate height-diameter model for birch in the European Russia. To select models which better describe the relationship between the heights and diameters of the trees, six metrics were used – root mean square error (RMSE), mean absolute percentage error (MAPE), coefficient of determination (R2), adjusted coefficient of determination (R2-adj.), Akaike information criterion (AIC) and Bayesian information criterion (BIC). Results show that there are slight differences between all models. The performance statistics showed that model M24 is the most suitable and recommended for predicting the height-diameter relationships for birch trees in this study area. The predicting variables for applying developed generalized models to estimate total tree height require less sampling effort and are derived from conventional forest inventory data which allows to reduce costs and time consumption in field work.