Efficiency In Relation Research Articles

Overvoltages at the incomplete phase modes of transformer operation in the networks of mining enterprises and methods of their limitation

The article presents analytical and graph-analytical methods of calculating overvoltages under incomplete-phase modes of power transformer operation with verification of their adequacy on mathematical models in Matlab Simulink software package. The existing solutions were analyzed for their efficiency in relation to mine networks. The overvolt-age levels at breakages in the most probable points of distribution network of one of the own open-pit mines of metal-lurgical enterprise have been determined. The circuit solutions for reducing the overvoltages on power transformers with different winding connection groups in incomplete phase modes of supply network operation have been developed and their mathematical models have been constructed. By means of Simulink package a number of calculations for deter-mining the necessary parameters of the proposed schemes of overvoltage limitation with graphical representation of the results have been made. Attention is paid to the unification of the study results for a wider and more flexible applica-tion.

Does Open Innovation Promote Innovation Efficiency in Chinese Universities?

The growing Chinese universities are implementing open innovation (OI). However, the function of OI in the innovation activities is still unclear. This article elaborates on how outbound OI (OOI) and inbound OI (IOI), which includes four types of partners [i.e., domestic research institutions, domestic higher education, domestic enterprises, and foreign institutions], influence the innovation efficiency of invention patents (IPA) and scientific papers (FPA) in the context of Chinese universities. Based on a panel dataset from 2009 to 2018 in China, we find that OOI significantly facilitates innovation efficiency of universities. IOI with DHE and FI can promote innovation efficiency in IPA and FPA, respectively. Moreover, we also investigate the moderating role of absorptive capacity in the relationship between OI and innovation efficiency. The results show some heterogeneity in the different types of OI. The study enriches the influencing factors of innovation efficiency in relation to OI and expands the research subject of OI topic. Furthermore, this article supplements the knowledge regarding the boundary conditions under which the effect of OI is strengthened or weakened.

Tremor-dominant form of Parkinson's disease

The article is of a review nature and is devoted to tremor, one of the maladaptive and difficult-to-treat symptoms of Parkinson's disease (PD). Along with the classic rest tremor, patients with PD may experience tremor of other modalities: postural tremor, kinetic tremor, which reflects a multimodal mechanism of tremor formation involving multiple neurotransmitter systems. The unpredictable response to therapeutic options, the ambiguous response to levodopa, also reflects the role of multiple underlying pathophysiological processes. Among the drug methods of tremor correction, preference is given to dopamine receptor agonists - due to the spectrum of their pharmaceutical action, high efficiency in relation to all leading motor and a number of non-motor manifestations. The evidence for advanced neurosurgical, non-invasive modalities is mixed, and there are insufficient comparative studies to assess their efficacy in patients with tremor-dominant forms of PD.

The exergetic approach for the analysis of HDH desalination process using a pulverized column

In the process of humidification-dehumidification, the cross transfer of heat and mass is due to the affinity between water and air. In the present work, a mathematical model was developed basing on the mass, thermal and exergy balances in order to analyse the performance of a freshwater productivity by desalination of seawater. Firstly, we acquired the thermodynamic properties of the binary system (air-vapour water) through the use of the virial equation of state. To determine the impact of operating variables on the performance of the unit, the concept of degrees of freedom has been introduced. Basing on a rigorous algorithm, the performance of HDH was approached by calculating the productivity of fresh water and exergetic efficiency in relation with the operating variables. The results of the simulation show that the productivity and the gained-output ratio (GOR) increase with the increase of the ratio of the flow rates and the temperature of the inlet air in the humidifier. However, it decreases simultaneously with the outlet water temperature. Besides, the humidifier and dehumidifier exergetic efficiencies increase simultaneously by increasing of the mass flow rates ratio and the temperature of the air at the inlet of the humidifier. Also, we note that the exergetic efficiency of the dehumidifier decreases with outlet water temperature. The simulation results establish that the collector performance diminishes with the liquid mass flow rate. Nevertheless, these results show that the major part of exergy destruction in the unit is localized in the collector with the lowest exergetic efficiency. The largest exergy losses are caused by increasing of the pinch of temperature.

Triple Bottom Line, Sustainability, and Regional Development

In a study of 74 Russian regions over the period of 2013–2018, this paper demonstrates that economic, social, and ecological dimensions of the triple bottom line triad positively and significantly affect regional development, thus validating the growing emphasis on sustainable development found in the literature and among policymakers. Investments in research and development, the creation of new firms, reductions in poverty rates, and lowering emission intensity lead to regional development. The study develops four models to analyze the regional resource allocation efficiency in relation to the economic, social, and ecological goals of sustainable development. To assess regional development, this paper calculates the technical efficiency of the regions concerning technological frontiers using Data Envelopment Analysis (DEA). As one of our variables (the border region dummy) is time-invariant, the study chose to estimate models with the help of a random effects estimator. The effects of startup rates and ecological factors are moderated by the per capita income within the region. The results suggest that the triple bottom line agenda is justified as a regional development paradigm.

33.8 W Mid-infrared 2.8 μm Er-doped fiber laser with high optical efficiency

We demonstrate an efficient, high-power single-end-pumped Er-doped ZBLAN (Er:ZBLAN) fiber laser operating at 2.8 μm. A maximum laser power of 33.8 W at a wavelength of 2.87 μm was achieved with an optical efficiency of 26.4 %. A maximum slope efficiency of 32.8 % was obtained, which approaches the Stokes efficiency of the intrinsic Er3+ energy transfer up-conversion process. We examine both experimentally and theoretically, the change in optical efficiency in relation to output coupling ratios, laser wavelength, and pump power. Simulations demonstrate that the Er:ZBLAN fiber laser system exhibits high gain at 2.8 μm, and red-shifting of the laser wavelength results in reduced laser field reabsorption and increased laser efficiency. To the best of our knowledge, this work demonstrates the highest output power generated from a single-end-pumped Er-doped fluoride fiber laser.

Impact of phosphorus omission fertilizer on growth, nutritional status, biochemical and physiological parameters in a Pinus taeda L. plantation

Low availability of phosphorus (P) in the soil is one of the factors limiting the productivity of Pinus taeda plantations. Phosphate fertilizer application in Pinus shows divergence in growth responses. Thus, understanding the response of plant photosynthetic efficiency and growth in relation to phosphate fertilizer application can serve as a basis to guide management practices in Pinus taeda plantations. The study aimed to evaluate the impact of P omission fertilizer on growth parameters, nutritional, biochemical, and physiological status of a Pinus taeda L. plantation. The experiment was conducted on a Pinus taeda plantation subjected to P fertilization: Control - without addition of N, P and K; P–fertilized - with addition of N, P and K; and P–omission - addition of N and K, and P omission fertilizer. The parameters height, stem and canopy diameter and productivity factor, P concentration in needles, soil available P, electron transport rate (ETRm), maximum quantum yield of PSII (Fv/Fm), initial (Fo) and maximum (Fm) fluorescence, chlorophyll a, b and total, carotenoids, superoxide dismutase (SOD) and peroxidase (POD), hydrogen peroxide (H2O2), lipid peroxidation (TBARS), and acid phosphatase activity, were evaluated. P fertilized application increased soil available P, providing largest P uptake by roots and P concentration in needles. The increase in available soil P contributed to elevate photosynthetic parameters, such as ETRm, Fv/Fm, chlorophyll a, b and total, and carotenoids. These factors contributed to increase C assimilation, height, stem and canopy diameter and productivity factor parameters. On the other hand, the P–omission and control conditioned the growth of Pinus taeda under stress, elevating the values of Fo, Fm, SOD and POD, which reduced plant development.

Al and other critical metals co-extraction from coal gangue through delamination pretreatment and recycling strategies

Coal gangue is an underused resource and there is a lack of its utilization in the green economy. This work aims at the clean recovery of critical metals in coal gangue, with the development of a recycling extraction process through repeated utilization of ammonia and ammonium salts, and development of delamination pretreatment methods to improve the extraction efficiency in relation to structural characteristics of aluminosilicate minerals in coal measures. The results showed that the pretreatment could replace the powder process, significantly improve the extraction efficiency and, simultaneously, inhibit the leaching of harmful elements. The leaching rates of Al, Li and Ga can be increased to 62.74%, 86.56%, and 46.18%, respectively, while the leaching of Pb was inhibited. Polymetallic products are potential raw materials for low-cost composite materials. The study developed and optimized a set of new ideas to promote the green extraction and utilization of critical metals in coal gangue.

An Expert Knowledge-Based System to Evaluate the Efficiency of Dry Construction Methods

The issues that the construction sector currently faces with regard to productivity and efficiency are well acknowledged. In the construction industry, there is plenty of space for efficiency to improve, with an increasing number of new tools and methods coming out. One of the solutions to increase efficiency is the application of modern methods of construction. The modern methods of construction, especially dry construction techniques, are developing so that there is a larger volume of high-quality production with a shorter time for procurement. Not only in the construction of skeletons but also in the finishing works, it is a huge advantage if there are implemented techniques that eliminate traditional wet construction works and thus shorten the construction time. On the other hand, however, the question of efficiency in relation to their costs is raised. Based on theoretical and empirical research, the aim of this study is to demonstrate the potential of modern dry construction systems and solutions for finishing works, especially in relation to the construction time and construction cost. For this purpose, an expert knowledge system, named the complex COMBINATOR, was developed. Through a set of simulations with the help of the COMBINATOR, the effects of different combinations of dry construction systems and techniques (DCSTs) and traditional wet construction systems and techniques (WCSTs) on the time and cost of finishing construction works were measured. Based on the results of simulations carried out through the complex COMBINATOR with an inference engine that enabled these simulations, the potential of dry construction techniques for the implementation of finishing works in the construction of residential buildings was demonstrated. Without simulating the effects of the individual technological models for finishing construction works in relation to two of the most important parameters of construction projects, namely time and cost, it would not be possible to obtain the resulting parameters for different combinations of DCSTs and WCSTs from the study presented. Therein lies the huge importance of the presented knowledge system for deciding on the benefits of DCSTs.

Application of the Monte-Carlo Method to Assess the Operational Reliability of a Household-Constructed Wetland with Vertical Flow: A Case Study in Poland

The objective of this study was to model the operation of a vertical-flow constructed wetland (VF-CW) for domestic wastewater, using Monte-Carlo simulations and selected probability distributions of various random variables. The analysis was based on collected wastewater quality data, including the values of the pollutant indicators BOD5 (biochemical oxygen demand), CODCr (chemical oxygen demand), and TSS (total suspended solids), in the 2017–2020 period. Anderson–Darling (A–D) statistics were applied to assess the fit of the theoretical distributions to the empirical distributions of the random variables under study. The selection of the best-fitting statistical distributions was determined using the percentage deviation (PBIAS) criterion. Based on the analyses that were performed, the best-fitting statistical distributions for the pollution indicators of the raw wastewater were the generalised extreme value distribution for BOD5, the Gaussian distribution for CODCr, and the log-normal distribution for TSS. For treated effluent, the log-normal distribution was the best fit for BOD5 and CODCr; the semi-normal distribution, for TSS. The new data generated using the Monte-Carlo method allowed the reliability of the VF-CW operation to be assessed by determining the reliability indices, i.e., the average efficiency of the removal of pollutants (η), the technological efficiency index (R), the reliability index (CR), and the risk index of the negative control of the sewage treatment plant operation (Re). The obtained results indicate that only in the case of CODCr, the analysed treatment facility may fail to meet the requirements related to the reduction of organic pollutants to the required level, which is evidenced by the values of the indicators CR = 1.10, R = 0.49, and η = 0.82. In addition, the risk index of the negative operation of the facility (Re) assumes a value of 1, which indicates that during the period of its operation, the VF-CW system will not operate with the required efficiency in relation to this indicator. The novelty of this work is the implementation of the indicated mathematical simulation methods for analysing the reliability of the operation of the domestic wastewater treatment facility.

Monitoring the cerebral venous drainage in space missions: the Drain Brain experiments of the Italian Space Agency

It is well known that the space environment induces major alterations to various human physiological systems, determining a general deconditioning of the body. Medical research programs aim to keep the astronaut’s health status during the mission, enable their ready operation once they arrive at their destination, and allow their safe recovery when returned to Earth. Among the programs coordinated and supported by the Italian Space Agency (ASI), the experiments called Drain Brain, performed by the University of Ferrara, are particularly relevant in this respect. The project, which began with the collaboration of Samantha Cristoforetti in 2014, has demonstrated the capability of a plethysmograph system to study the cerebral circulation and the venous return from the brain to the heart, onboard the International Space Station (ISS). Demonstrating the progressive reduction of the cross-sectional area of the internal jugular vein, particularly significant between pre-flight data collection and the last assessment after 6 months of flight on the ISS (p<0.001). Over the next two years, thanks to the Drain Brain 2.0 project, crews of the International Space Station will be studied with a new version of the plethysmograph, synchronized with the electrocardiogram, to assess cardiac efficiency and brain drainage in relation to symptoms such as blurred vision, numbness, or the feared onset of jugular thrombosis, that is linked to blood flow slowdown due to the absence of the gravitational gradient. Drain Brain 2.0 will also generate important returns to Earth, closing the virtuous circle of terrestrial application of space research.

Economic Efficiency of Public Administration in the Field of Digital Development

"In the article, based on the analysis of the essential characteristics of digitalization, it is proposed to consider the concept of efficiency in relation to the activities of public authorities as a generalized and interconnected series of such concepts as economy, qualimetricity, and effectiveness. The efficiency of public administration, including economic efficiency, is considered as the implementation of management, during which the set goals are achieved (solving a certain socially significant problem, satisfying the interests of the population, maintaining digital competitiveness of region and country) while minimizing costs and observing the current standards of digital maturity. It is proposed to understand the assessment of the effectiveness of public administration as a set of methods for measuring actual indicators that reflect the results of the public authorities’ activities within the framework of the strategies, programs, and projects being implemented in accordance with the criteria laid down in them, and in this case the assessment is seen as the direct result of such a measurement, which serves to compare the activities of public administration subjects, compare this activity with the declared goals, the results of past periods. The proposed leading and signal indicators can be used in planning and forecasting the level of digital development of regional socio-economic systems."

Physico-mechanical properties and shielding efficiency in relation to mineralogical and geochemical compositions of Um Had granitoid, Central Eastern Desert, Egypt

The current work aims to describe the physico-mechanical characteristics and shielding efficiency with reference to the mineralogical and geochemical compositions of the Neoproterozoic Um Had composite granitoid pluton in order to deduce their favorability as dimension stones. The Um Had granitoid pluton has an elliptical outline with a mean diameter of about 10 km. This pluton is a composite (ranging from white to reddish pink color), hard, massive, and medium- to coarse-grained granitoid body. It is classified as syenogranite according to their modal and bulk chemical compositions. Geochemically, the granitoid pluton is a highly calc-alkaline, peraluminous granite, formed by low degree partial melting of tonalitic source rock in a post-collisional tectonic setting. The physico-mechanical properties of the granitoid pluton under study satisfy the requirements of dimension stone in terms of their bulk density (from 2561 to 2564 kg/m3), and to some extent water absorption capacity (from 0.38% to 0.55%). However, their compressive strength values (50.4–113.4 MPa) do not achieve the minimum requirement for interior use and light duty exterior use. This study delves into the potential of some of our syenogranite samples (I, IIA, IIS, and 10) as gamma radiation shielding materials. We have assessed the mass attenuation coefficient (GMAC), effective atomic number (Zeff), exposure build-up factor (EBF), and energy absorption build-up factor (EABF) for each of these samples. The GMAC and Zeff calculations were performed using the Phy-X online software, across a photon energy range of 0.015–15 MeV. Our findings suggest an inverse relationship between photon energy and GMAC, with the highest values observed for the (I) granite sample (∼18). This study shows the promising radiation shielding capacity of our samples. The insights derived from GMAC, Zeff, EBF, and EABF can serve as a guide for the development of effective, naturally sourced radiation shielding materials.

How to Quantify the Adsorption of Cyanuric Acid on Activated Carbon Used from Swimming Pool Disinfection?

The physical and chemical characteristics of an adsorbent are key factors determining its efficiency in relation to a particular adsorbate molecule. The adsorption of cyanuric acid (cya) on activated carbon (AC) has not been extensively explored in terms of its basic phenomenon and specific surface interactions. Cya is an important molecule in the swimming pool industry, as it protects free chlorine from UV light degradation. A proper characterization of AC will be beneficial for swimming pool product suppliers to determine the criteria while purchasing it to remove excess cya accumulated in pools. A detailed investigation of the physicochemical properties of activated carbon was conducted to assess its potential to adsorb cya from water. The effect of the adsorption capacity under various pH conditions was studied and it was found that acidic pH favors the adsorption process. With the help of temperature-programmed desorption coupled with mass spectrometry (TPD-MS) and X-ray photoelectron spectroscopy (XPS), the surface chemistry was well analyzed for a proper understanding of the adsorbent-adsorbate interaction. While conventional pool test equipment gives inconsistent readings of the cya concentration, a UV-vis spectroscopy-based methodology has been developed to accurately measure traces of cya in water. This method can be helpful to validate the accuracy of pool-testers for research and development purposes. The batch adsorption experiments revealed that cya adsorption on activated carbon follows pseudo-second-order kinetics, which confirms that the adsorption mechanism is chemisorption, which in fact, depends highly on the surface chemistry of the AC and the reaction pH.

Intrinsic brain connectivity alterations despite intact pain inhibition in subjects with neuropathic pain after spinal cord injury: a pilot study

Endogenous pain modulation in humans is frequently investigated with conditioned pain modulation (CPM). Deficient pain inhibition is a proposed mechanism that contributes to neuropathic pain (NP) after spinal cord injury (SCI). Recent studies have combined CPM testing and neuroimaging to reveal neural correlates of CPM efficiency in chronic pain. This study investigated differences in CPM efficiency in relation to resting-state functional connectivity (rsFC) between 12 SCI-NP subjects and 13 age- and sex-matched healthy controls (HC). Twelve and 11 SCI-NP subjects were included in psychophysical and rsFC analyses, respectively. All HC were included in the final analyses. Psychophysical readouts were analysed to determine CPM efficiency within and between cohorts. Group differences of rsFC, in relation to CPM efficiency, were explored with seed-to-voxel rsFC analyses with pain modulatory regions, e.g. ventrolateral periaqueductal gray (vlPAG) and amygdala. Overall, pain inhibition was not deficient in SCI-NP subjects and was greater in those with more intense NP. Greater pain inhibition was associated with weaker rsFC between the vlPAG and amygdala with the visual and frontal cortex, respectively, in SCI-NP subjects but with stronger rsFC in HC. Taken together, SCI-NP subjects present with intact pain inhibition, but can be differentiated from HC by an inverse relationship between CPM efficiency and intrinsic connectivity of supraspinal regions. Future studies with larger cohorts are necessary to consolidate the findings in this study.

An Optimal Hierarchical Approach for Oral Cancer Diagnosis Using Rough Set Theory and an Amended Version of the Competitive Search Algorithm.

Oral cancer is introduced as the uncontrolled cells' growth that causes destruction and damage to nearby tissues. This occurs when a sore or lump grows in the mouth that does not disappear. Cancers of the cheeks, lips, floor of the mouth, tongue, sinuses, hard and soft palate, and lungs (throat) are types of this cancer that will be deadly if not detected and cured in the beginning stages. The present study proposes a new pipeline procedure for providing an efficient diagnosis system for oral cancer images. In this procedure, after preprocessing and segmenting the area of interest of the inputted images, the useful characteristics are achieved. Then, some number of useful features are selected, and the others are removed to simplify the method complexity. Finally, the selected features move into a support vector machine (SVM) to classify the images by selected characteristics. The feature selection and classification steps are optimized by an amended version of the competitive search optimizer. The technique is finally implemented on the Oral Cancer (Lips and Tongue) images (OCI) dataset, and its achievements are confirmed by the comparison of it with some other latest techniques, which are weight balancing, a support vector machine, a gray-level co-occurrence matrix (GLCM), the deep method, transfer learning, mobile microscopy, and quadratic discriminant analysis. The simulation results were authenticated by four indicators and indicated the suggested method's efficiency in relation to the others in diagnosing the oral cancer cases.

Framework for identifying network attacks through packet inspection using machine learning

Abstract In every network, traffic anomaly detection system is an essential field of study. In the communication system, there are various protocols and intrusions. It is still a testing area to find high precision to boost the correct distribution ratio. Many authors have worked on various algorithms such as simple classification, K-Means, Genetic Algorithm, and Support Vector Machine approaches, and they presented the efficiency and accuracy of these algorithms. In this article, we have proposed a feature extraction technique known as “k-means clustering,” which has its roots in signal processing and is employed to divide a set of n observations into k clusters, each of which has its origin from the observation with the closest mean. K-Means method is applied in this study to investigate the stream and its implementation and applications using Python and the dataset on the KDDcup99. The effectiveness of the outcome indicates the planned work’s efficiency in relation to other widely available alternatives. Apart from the applied method, a web-based framework is designed, which can inspect an actual network traffic packet for identifying network attacks. Instead of using a static file for testing the network attack, a web page-based solution uses database to collect and test the information. Real-time packet inspection is provided in the proposed work for identifying new attacks.

PHÂN TÍCH HIỆU QUẢ KINH DOANH TRONG MỐI QUAN HỆ VỚI ĐÒN BẨY TÀI CHÍNH CỦA CÁC CÔNG TY CỔ PHẦN SẢN XUẤT THÉP NIÊM YẾT TRÊN THỊ TRƯỜNG CHỨNG KHOÁN VIỆT NAM ANALYSIS ON¬ PROFITABLITY IN RELATION TO FINANCIAL LEVERAGE OF PUBLIC STEEL MANUFACTURING COMPANIES ON VIETNAMESE STOCK MARKET

Analyzing business efficiency in relation to financial leverage comprises a fundamental segment in enterprises financial analysis. The use of indicators such as ROI, ROA, ROE, ROS, EPS, DC can help the evaluation of economic profitability of capital, assets, costs in relation to the use of debt of the administrator. Vietnam's steel production joint stock companies have recently been affected by the world economic recession and the covid 19 epidemic, and the results of production and business activities over the years 2019-2022 have had many fluctuations and abnormalities. The author's article studies the business performance of 3 steel manufacturing joint stock companies listed on the Vietnamese stock market in relation to financial leverage. Through the analysis, the authors give recommendations on using solutions to improve business efficiency and reasonable financial leverage for these enterprises in the coming time. Keywords: business performance analysis, steel manufacturing companies, financial leverage. JEL Classification: M00, M10, M21

PRIMARY OIL REFINING AND HEAT EXCHANGER APPARATUS

Different technological processes are applied in the field of modern oil refining. Each of the processes in turn is implemented by many technological schemes and methods. In petroleum refining and chemical production, these technological processes provide the basis for many simple processes. In this way, the learning of the processes is facilitated. They process oil and its products by applying various processes. Oil refining and its main organic synthesis plants are composed of a collection of various technological processes and general plant farms. Depending on the number and quality of the products received from the factories, great attention is paid to the supply of hardware and equipment. It is through these equipment and devices that technological processes are carried out. Heat exchangers are among the most commonly used devices in the oil refining industry. The most common type of heat exchangers are shell-and-tube heat exchangers. Shell and tube heat exchangers are technological in the oil and gas industry pretreatment to improve properties and reduce viscosity of streams stages are widely used. Distribution of shell-and-tube heat exchanger design reliability and due to the variety of types and versions to work in a wide range of temperature, pressure and corrosive environment. At the current stage of production development, an important trend is increasing the efficiency of the used technological equipment, ensuring high energy efficiency in relation to heat exchange equipment. Flat cross-sections of different configurations are used to organize the cross current in the inter-tube space of the heat exchanger and to increase the cooling speed. The presence of such partitions significantly complicates the flow pattern of the cooling liquid, and is reliable for the flow around the tube bundle. Currently used methods of heat exchanger heat calculation based on criterion dependencies do not take into account all characteristics of the flow. Keywords: Boiler, reactor, heater, furnace, filter, air cooler, electrodehydrator, gasoline, diesel, catalyst, injector, pump, piping, hot flow, cold flow.

ANNA: advanced neural network algorithm for optimisation of structures

The purpose of this study is to develop an advanced neural network algorithm as a new optimisation for the optimal design of truss structures. The central concept of the algorithm is based on biological nerve structures and artificial neural networks. The performance of the proposed method is explored in engineering design problems. Two efficient methods for improving the standard neural network algorithm are considered here. The first is an enhanced initialisation mechanism based on opposite-based learning. The second relies on using a few tunable parameters to provide proper exploration and exploitation abilities for the algorithm, enabling better solutions to be found while the required structural analyses are reduced. The new algorithm's performance is investigated by using five well-known restricted benchmarks to assess its efficiency in relation to the latest optimisation techniques. The outcome of the examples demonstrates that the upgraded version of the algorithm has increased efficacy and robustness in comparison with the original version of the algorithm and some other methods.