Assistance system for real-time polyp detection based on convolutional neural network

Summary: The use of artifi cial intelligence as an assistive detection method in endoscopy has attracted increasing interest in recent years. Machine learning algorithms promise to improve the effi ciency of polyp detection and even optical localization of fi ndings, all with minimal training of the endoscopist. The practical goal of this study is to analyse the CAD software (computer-aided dia gnosis) Carebot for colorectal polyp detection using a convolutional neural network. The proposed binary classifier for polyp detection achieves accuracy of up to 98%, specifi city of 0.99 and precision of 0.96. At the same time, the need for the availability of large-scale clinical data for the development of artifi cial- -intelligence-based models for the automatic detection of adenomas and benign neoplastic lesions is discussed. Key words: polyp detection – convolutional neural network – artifi cial intelligence – computer-aided dia gnosis – spatial location

Results of chalazion cryosurgery with an increased risk of complications

Background. At an appointment with an ophthalmologist, patients with pathological conditions of the eyelids are often dissatisfi ed with the effectiveness of the traditional surgical treatment.The aim: assessment of the functional state of the eye adnexa after cryodestruction of the chalazion with an increased risk of complications using modern cryosurgical equipment.Material and methods. Clinical studies were carried out in 254 patients (277 eyes) with chalazion, including a complicated course of the disease, with cryodestruction of the chalazion using an autonomous cryoapplicator made of porous-permeable titanium nickelide.Results. Cryosystems of the new generation, in comparison with the well-known industrial cryoapparatus, diff er in new properties. They can signifi cantly improve the quality of cryotherapy in surgery due to a clearer localization of cryotherapy and a high rate of heat removal from the surface of altered tissues without damaging the surrounding tissues. Depending on the size of the pathological formation, the duration of the exposure, the frequency of repetitions of the applications during the session, the regression of the chalazion occurred within 1–1.5 months with the preservation of the integrity of the intermarginal space and the functional state of the eyelid.Conclusion. Analysis of the data obtained indicates a high clinical and cosmetic effi ciency of cryosurgery of the eyelid chalazion using an autonomous cryoapplicator made of porous-permeable titanium nickelide.

Role and Features of External and Internal Audit in Universities

The article substantiates the feasibility of auditing at universities, examines the main diff erences between the goals, objectives, features of external and internal audit in universities and its impact on the effi ciency of fi nancial and economic activities. New in the article is the identifi cation of the peculiarities of external and internal audit in higher educational institutions, the formulation of the concept of «internal audit at the university», the defi nition of tasks that can be set for internal audit as well as consideration of options for the formation of a subordination scheme of the internal audit unit at the university to ensure maximum the possible level of independence. The results of this study are of theoretical and practical importance for the management of the university, which forms the development strategy and is responsible for the eff ectiveness of the functioning of the university.

TADF/RTP OLED organic emitters based on concaved N-PAHs with tunable intrinsic D-A electronic structure

Polycyclic aromatic hydrocarbons (PAHs) with centrally positioned nitrogen dopants possess a unique curved structure and strong electron-donating features. However, the lack of tools to synthetically affect their bandgap engineering and charge-transfer (CT) characteristic is detrimental to their future optoelectronics use because of usually low PLQY effi-ciency. Facing this challenge, we report on developing the first fully conjugated, curved N-PAHs containing phenazine terminus with the D-A electronic structures, which are herein studied as functional optoelectronic material. We evidence the influence of curvature on minimizing HOMO-LUMO overlap, which was severely reflected in small ΔEST values, in-dispensable to enhance the RISC rate constant. Within this approach, we evaluate the utility of the concaved system as TADF/RTP emitters which has not been explored so far in the context of non-planar N-PAHs. By variable accepting strength of phenazines employed, the photoluminescence quantum yields (ΦPL) were tuned, ranging from the lowest 9% up to the highest 86% with dinitrile terminus. As a proof of concept, solid-state OLED devices were constructed, exhibit-ing yellow to orange emission with the best maximum external EL quantum efficiency (EQE) of 12% for acceptor built up on 3-(trifluoromethyl)phenyl decorated phenazine that is demonstrated for the first time for curved D-A embedded N-PAHs.

Opportunities and Challenges for Field Experiment Equipment

Modern seed industry development could contribute up to 40 percent to increase agricultural production and effi ciency. Mechanization of fi eld experiments is an important means to improve the effi ciency and precision of fi eld breeding experiments. There is a big gap in the mechanization level and development of fi eld experiments in diff erent countries of the world. The International Association on Mechanization of Field Experiments established in 1964 has played a great role in promoting the development of fi eld experiment mechanization in the world. At present, the advanced fi eld experiment equipment is mainly concentrated in international manufacturers such as Wintersteiger in Austria, Almaco in the United States, Haldrup and Zürn in Germany. As a great agricultural country, China’s demand for rice and maize seeds, the major food crops in the last 10 years, is about 250 million kilograms and 1.15 billion kilograms, respectively. A large amount of demand for seeds prompted China’s fi eld experiment mechanization that has made great progress. The research team of Qingdao Agricultural University has developed 16 types of new plot planters and plot harvesters which have been popularized and applied in China. But diff erent crops, planting patterns and regional characteristics put forward higher requirements for adaptability of fi eld experiment equipment. The precision of the seeder, the cleaning performance of the seeding and harvesting equipment and the intelligent technology of the equipment need to be further improved. In future development, more attention should be paid to the integration of modern information technology and intelligent technology into fi eld test equipment, to improve operational effi ciency and accuracy.

Current Situation and Development Trend of China’s Agricultural Machinery Distribution

In the year of 2021, the Chinese government allocated 19 billion RMB for agricultural machinery subsidy. The data that accurately describes the scale of China’s agricultural machinery market could be calculated by analyzing the national agricultural machinery purchase investment, the total value of the parts market and the replacement market could be inferred. Since the implementation of agricultural machinery purchase subsidies, China’s comprehensive mechanization rate of crop cultivation, planting and harvesting has increased rapidly. In 2019, the national comprehensive mechanization rate of crop cultivation, planting and harvesting exceeded 70 percent, and the production of the three major food crops of wheat, rice and corn was basically mechanized. This paper analyzes the scale of the complete machinery market, the market scale of key products in the Chinese agricultural machinery market, the basic situation of Chinese agricultural machinery distribution companies, the basic situation of the Chinese agricultural machinery purchasing groups, and the main gathering platforms of the Chinese agricultural machinery distribution market, explaining the current status of China’s agricultural machinery distribution, putting forward suggestions for the development of China’s agricultural machinery distribution market. There are major contradictions in the agricultural machinery market in China. The most important one is between supply and demand. In terms of crops, the level of comprehensive mechanization of wheat, rice and maize is relatively high, while the level of comprehensive mechanization of cash crops such as cotton oil, sugar and vegetable tea is relatively low; from a regional perspective, the level of mechanization in the northern plains is relatively high, and the level of mechanization in the hilly and mountainous areas of the south is relatively low; from an industrial point of view, the level of mechanization of planting industry is relatively high, while the level of mechanization of animal husbandry, fi shery and processing is low. Meanwhile, the contradiction between manufacturers and distributors, as well as the end-users is further intensifying. This article attempts to explain the effi ciency and benefi t of agriculture and the return on investment of agricultural machinery purchase. Only when agriculture is competitive, has good effi ciency and benefi ts, and the purchase of agricultural machinery has a good rate of return on investment, can the industry develop healthily.

ANALYSIS OF THE EFFICIENCY OF ACOUSTIC SCREENS OF DIFFERENT DESIGNS

Various sources of noise in cities and ways to combat them are considered. The effi ciency of two types of acoustic screens is analyzed: single-layer and two-and three-layer. The positive and negative characteristics of various designs of existing acoustic screens are listed. A fundamentally new design of the acoustic screen is described: the panels have a ridge profi le, they are located along the vertical axis of the frame with a step at which the panels above the located ridge cover the top of the lower ridge, the outer surfaces of the panels and their end parts are made of a material that has sound-refl ecting properties, and the inner surfaces of the panels are made of sound-absorbing material. Such an acoustic screen is devoid of the disadvantages inherent in acoustic screens of other structures and is more effi cient. The considered invention allows due to the use of the ridge shape of acoustic panels: prevent the refl ection of sound energy in the direction of noise sources (a small part will be directed upwards); provide almost complete absorption of sound energy as it passes through the channels formed by the ridge panels; provide the same effective protection against noise sources located on both sides of the screen; prevent the formation of snow and ice crust on sound-absorbing surfaces, which ensures the constant eff ectiveness of the screen in diff erent seasons of the year; reduce metal consumption, which will reduce the weight of the structure without reducing its effi ciency and reduce the cost of acoustic screens.

ECONOMIC DAMAGE ASSESSMENT METHODOLOGY IN CASE OF TRANSFORMER LOAD RATIO DEVIATION

The aim of the study is to develop a methodology for assessing economic damage when the transformer load factor deviates. In the process of research, a method was used to determine the optimal load of a power transformer. A method for assessing economic damage in case of a deviation of its load factor has been developed. The optimal load factor of a power transformer has been determined according to the criterion of the minimum cost of money for the transformation of electrical energy. The load level of power transformers can be assessed by two criteria: by the maximum integral value of the effi ciency and by the minimum loss of money during the transformation of electricity. According to the proposed methodology, the assessment of damage is carried out when the load factor of the transformer deviates from the optimal values, for which the relative losses of electrical energy are calculated. The results obtained when evaluating energy and fi nancial and economic effi ciency show that when the load factor is overestimated relative to the optimal values, it is much more preferable to overestimate than underestimate. The reliability of the results is confi rmed by the satisfactory agreement of the calculated results with the experimental data obtained at the operating power plant.

ANALYSIS OF THE METHOD OF DETERMINING THE OPTIMAL VOLUME OF THE STORAGE RESERVOIR FOR THE POWER COMPLEX AS PART OF THE WES-PSPP

The article considers the peculiarities of using energy complexes as part of the WPP-PSPP. It is noted that the most relevant and promising will be the use of such energy complexes in environmentally unfavorable regions that are not among the priorities for the development of wind energy. However, the energy complexes as part of the WPP-PSPP are not currently widespread, one of the reasons is the lack of methods for calculating the optimal parameters of the energy complexes, which should include calculations to determine the volume of the storage reservoir of the energy complex. As a result of solving problems using the analysis of methods of economic effi ciency, methods of ecological justifi cation for autonomous power supply systems, a methodology was developed to determine the optimal volume of the storage reservoir for the energy complex as part of the WPP-PSPP, the main provisions of which are described in this article. The presented methodology allows you to choose the most rational location and shape of the accumulating reservoir on the ground, to fi t the outline of the reservoir into natural conditions, as well as to optimize the ratio of its depth of work and cross-sectional area.

INTENSIFICATION AND STUDY OF HEAT TRANSFER AND FRICTION IN THE PLATE HEATING SURFACES OF THE KMS-2 AIR HEATER WITH A PRESSURE GRADIENT

A numerical study of heat transfer and friction in the heat exchanger channels in the presence of a variable pressure gradient is performed. The research was carried out in software complexes (Code_Saturne, Salome). The results of the validation of the research method are presented and they showed that the deviation of the numerical simulation results from the calculation data according to the known criterion equations is within the error of generalization of the experimental data by the criterion equations. According to the results of studies at Red=3000, Red=4177, Red=6000, it was found that the average value of the heat transfer coeffi cient of the channel of variable cross-section is up to 20 % higher than for the channel at dp/dx0. At the same time, the thermal-hydraulic effi ciency of the alternating channel (L=117 mm, l=58.5 mm, n=2) in the initial section at x =0...0.08 is lower than in the channel with dp/dx>0 by 26.7 %, and at x =0.08...1 it is higher by 5 ... 15 %, at dp/dx