Design and Analysis of Terminal Guidance Law for Kinetic Interceptors based on Pulse Engine

A new terminal guidance law is proposed based on a solid propellant pulse engine and an improved proportional navigation method to address the terminal guidance issue for kinetic interceptors.On this basis,the start-stop curve of the pulse motor during the terminal guidance process is designed,along with its start-up logic.The effectiveness of the proposed guidance strategy is verified through simulation.

Cooperative trajectory optimization of UAVs in approaching stage using feedback guidance methods

This paper mainly studies the problem of using UAVs to provide accurate remote target indication for hypersonic projectiles.Based on the optimal trajectory trends and feedback guidance methods,a new cooperative control algorithm is proposed to optimize trajectories of multi-UAVs for target tracking in approaching stage.Based on UAV kinematics and sensor performance models,optimal trajectory trends of UAVs are analyzed theoretically.Then,feedback guidance methods are proposed under the optimal observation trends of UAVs in the approaching target stage,producing trajectories with far less computational complexity and performance very close to the best-known trajectories.Next,the sufficient condition for the UAV to form the optimal observation configuration by the feedback guidance method is presented,which guarantees that the proposed method can optimize the observation trajectory of the UAV in approaching stage.Finally,the feedback guidance method is numerically simulated.Simulation results demonstrate that the estimation performance of the feedback guidance method is superior to the Lyapunov guidance vector field(LGVF)method and verify the effectiveness of the proposed method.Additionally,compared with the receding horizon optimization(RHO)method,the proposed method has the same optimization ability as the RHO method and better real-time performance.

Detection of wheat seedling lines in the complex environment via deep learning

Wheat seedling line detection is critical for precision agriculture and automatic guidance in early wheat field operation. Aiming at the complex wheat field environment, a method of detecting wheat seedling lines based on deep learning was proposed in this study. Firstly, a rotated bounding box was created to improve the YOLOv3 model to predict the approximate position of the wheat seedling line;Then, according to the rotated bounding region obtained by the model, the wheat seedling line was detected by fitting the extracted center points. Finally, a comprehensive evaluation method combining angle error and distance error was proposed to evaluate the accuracy of the extracted crop line. By testing images of wheat seedlings in different environments, the results showed that the mean angle error and distance error respectively reached 0.75° and 10.84 pixels while the mean running time was 63.83 ms for a 1920×1080 pixels image. And compared to the original model the improved algorithm model improved the mAP value by 13.2%. The angle error and the distance error of the improved algorithm model were reduced by 51.4% and 39.7%, respectively. The method proposed in this study can accurately detect the wheat seedling lines at different stages and it is also suitable for the environments with weeds, shadow, bright light, and dark light. At the same time, it has a certain adaptability to wheat seedling images with a yaw angle in the shooting process. The research results could provide a reference for the automatic guidance of early wheat field machinery.

Some Methods of Improving the Ability of Doing Reading Comprehension Exercises in PRETCO-A

Practical English Test for Colleges (PRETCO) examination is very important to higher vocational college students. Reading comprehension section, moreover, is the key part in the examination because it, in some degree, influences the total score of the examination. In this passage, the author is to illustrate some reading methods to help the students master the spirit of reading comprehension and grasp the methods and strategy of then so that they could get high score in this part.

An application of Genre-based Teaching Approaches into the teaching of English reading and writing

There are several teaching approaches being used to instruct the reading and writing teaching, such as the product approach, the process approach and the genre approach. In a long period, the product approach and the process approach dominate the field of writing teaching. With the development of genre and genre-analysis theory, we begin to realize that genre-based approach is effective in improving students ’ reading comprehension and writing. Based on the analysis of the theory and on the present situations of college English teaching and personal teaching experience, the genre-based teaching approach is introduced to the writing and reading comprehension teaching.

Research on the Reform of the Course“Reading of Concrete Structure Plan and Construction Drawings”Under the Background of“Promoting Teaching and Learning Through Competitions”

The inherent teaching approach can no longer meet the demands of society.In this paper,current issues within the teaching landscape of architectural engineering technology in higher vocational colleges as well as the policies and teaching demands that formed the basis of this model were analyzed.The study shows the importance of the implementation of the teaching model“promoting teaching and learning through competitions.”This model puts emphasis on the curriculum and teaching resources,while also integrating the teaching process and evaluation with competition.These efforts aim to drive education reform in order to better align with the objectives of vocational education personnel training,while also acting as a reference for similar courses.

3-47 Reproducibility of Breathing Guidance Method for Respiratory Motion Management in Synchrotron-based Gated Heavy-ion Beam Delivery

A novel breathing guidance method by combining the personalized audio-visual biofeedback (BFB) system, the breath hold (BH) method, and the synchrotron-based gating technique have been developed to help patients synchronize their respiratory patterns with the synchrotron pulsed operation manner so as to overcome typical limitations such as low efficiency and residual motion[1;2]. This year we chose four fractions to evaluate the reproducibility of subject compliance with the breathing guidance maneuvers among different fractions for the breathing guidance technique.

Use of the Method of Guidance by a Required Velocity in Control of Spacecraft Attitude

We apply the method of guidance by a required velocity for solving the optimal control problem over spacecraft’s reorientation from known initial attitude into a required final attitude.We suppose that attitude control is carried out by impulse jet engines.For optimization of fuel consumption,the controlling moments are calculated and formed according to the method of free trajectories together with principle of iterative control using the quaternions for generating commands to actuators.Optimal solution corresponds to the principle“acceleration-free rotation-separate corrections-free rotation-braking”.Rotation along a hitting trajectory is supported by insignificant correction of the uncontrolled motion at discrete instants between segments of acceleration and braking.Various strategies of forming the correction impulses during stage of free motion are suggested.Improving accuracy of achievement of spacecraft's final position is reached by terminal control using information about current attitude and angular velocity measurements for determining an instant of beginning of braking(condition for start of braking based on actual motion parameters is formulated in analytical form).The described method is universal and invariant relative to moments of inertia.Developed laws of attitude control concern the algorithms with prognostic model,the synthesized control modes are invariant with respect to both external perturbations and parametric errors.Results of mathematical modeling are presented that demonstrate practical feasibility and high efficiency of designed algorithms.

Optimum Design of the Control System for a Laser Beam Riding Guidance Anti-Tank Missile

The optimum theory and methods were adopted to design the laser beam riding guidance anti tank missile's control system in the short run. Through building the mathematical model of system, selecting a proper method and taking advantage of computer's high speed calculation and logic traits, an optimal controller was designed. Simulation results showed that the designed control system has fair performance and it satisfies the tactical and technical requirements. The results also demonstrate that by the combination of the optimizing methods and the computer the control system could be designed as soon as possible.

An Action Research Project Aiming to Improve the Students' Reading Skills and Performance in an EFL Reading Class

As is universally acknowledged,educators have endeavored for ages to seek the more effective teaching method.Then action research has become a tool which is frequently applied to the teaching practice aiming to locate the teaching mode satisfactory to both teachers and students.The English majors are required to pass the TEM-4 exam when they are sophomores.It is essential for them to acquire the effective learning skills from reading classes.But it seems that vocabulary and grammar study—so called the traditional teaching method prove boring to students.Therefore,the tapestry approach is put forward.But the question is though the tapestry approach stimulates students’interest,can it can improve their English level?In order to figure out the result,two classes will be chosen in this research—one is controlled class,the other is experimental class.The traditional teaching method and the tapestry approach will be used in these two classes respectively.The experiment will last one semester.The students will be tested on two same TEM-4 papers at the beginning and at the end of the semester.The data will be collected for comparison.If the experimental class get the higher scores in the TEM-4 paper,it demonstrates that the tapestry approach is successful in balancing the need for interests and the need for English improvement.

The Application of English New spaper Reading in English Learning and Its Problems

Reading is the basic way for learners to study English,to obtain various information as well as knowledge,and to improve the proficiency of understanding and expressing.English newspaper reading,owing to its own characteristics,will make up for the shortcomings of conventional textbooks at quite a high level.The primary goal of this research is to investigate the general situation of English newspaper reading among college students,their attitudes toward the teaching of English newspaper reading and their problems in reading newspapers by conducting a questionnaire among non-English majors.Finally,it suggests a reasonable method of English newspaper learning based on the problems this questionnaire indicates.

Analysis of an Extensive Heavy Rainfall Weather Process during 23-24 April, 2021 in China

An extensive rainfall occurred in central and eastern China during 23-24 April, 2021. This research mainly uses the reanalysis data of NCEP/NCAR every 6 hours to analyze this heavy rainfall weather process. The results show that the main reason for this precipitation process is the shear formed between the cold air and the warm and humid air flow in the southwest. The low temperature on the ground allows the warm and humid air flow to lift up to form precipitation. The shear system is strengthened to a low vortex, which greatly strengthens the vertical ascent movement. Good water vapor and dynamic conditions form a large range of heavy rainfall.

Study on Numerical Comparison Method of Four-bar Straight-line Guidance Mechanism

In order to solve four-bar straight-line guidance mechanism synthesis problem for the arbitrarily given straight-line’s"angle requirement"and"point-position requirement",a numerical comparison synthesis method for single and double straight-line guidance mechanism is presented,which is convenient to realize by computer program.The basic idea of this method is:to select a four-bar linkage whose relative bar length of crank is 1 as a basic four-bar linkage.Then the other three relative bars’length is changed,and a lot of basic four-bar linkage can be obtained.There are many single and double ball-points of each basic four-bar linkage.With the motion of a basic four-bar linkage,there is straight-line segment of each Ball-point’s path.The data of these basic four-bar linkages is saved to a database.When designing a four-bar straight-line guidance mechanism,the design data is compared with the data in database and a satisfactory four-bar linkage can be obtained.The method effectively solves the straight-line guidance mechanism synthesis problem.

Plotinian Methodology and Hermeneutics： Philosophy or History of Philosophy？

The present paper has a double aim： （1） it attempts to present an aspect of Plotinus＇ philosophical and hermeneutical methodology on the basis of relevant remarks in the treatise ＂On Eternity and Time＂; （2） it seeks to connect this attitude with contemporary methodological questions concerning the relation between philosophy and history of philosophy. After an introduction where it is emphasized that the term ＂Neo-Platonism＂ is of recent coinage, I exploit David Sedley＇s remarks regarding the function of ancient philosophical schools： the quest for the ＂correct＂ interpretation of the school＇s founder as a philosophical enterprise in itself is not an exclusively Neoplatonic characteristic. Nonetheless, the example of Plotinus＇ Enneads III.7, owing to the complexity of its theme, shows that Plotinus does not pay attention only to the Platonic teachings regarding eternity and time, but also to all the other philosophical schools＇ theories, including the Epicurean. The aim is the ascertainment of the truth inherent in them and its apt interpretation. Hence, I follow Steven K. Strange （1950-2009）, who relates the Plotinian methodology to Aristotle＇s endoxic method. After a presentation of similarities and differences between the two philosophers, I conclude that the problematic features posed by several philosophical theories are resolved via an innovative Plotinian reading of Plato. Thus, the non-Platonic theories play a role in the more adequate interpretation of Plato, which is identified with the successful answer to the philosophical problems. This fact makes us wonder as to the best characterization of Plotinus＇ enterprise： philosophy or history of philosophy？ Although the question is somehow anachronistic, Plotinus gives an explicit response in his aforementioned tractate： to the extent that he is interested in solving philosophical problems, rather than compiling a ＂catalogue＂ of past philosophical positions, his enterprise is not historical, but philosophical. Two final corollaries stem from this： （i） to a certain extent, the previous enunciation explains the Neoplatonic reading of Plato; （ii） it teaches us that the difference between philosophizing and a historical treatment of philosophy does not lie only on the content, but also on the manner according to which the interpreter approaches past or contemporary philosophers.

On the three-layer passage reading method in English extensive reading

This paper raises, for the first time, with a model reading passage, a three-layer passage reading method （3LPRM in brief ） in English reading： reading beyond paragraphs; reading within paragraphs and sentences, and reading with coherences of words and expressions. The paper illustrates the definition, contents, characteristics and application of the method which is easy to master and apply. The paper aims at supplying readers especially beginners of E/S/FL （English as second/foreign language） with a practical passage reading method so as to improve their reading efficiency. The paper has some practical significance and directing value.

Analysis of the Factors Influencing English Teaching in Junior and Senior High Schools and Countermeasures

Smooth degree of connection on English teaching in Junior and Senior high schools directly affects the quality of English Teaching in senior high school. At present, the separate school running system from many local junior and senior high schools makes it difficult for senior high school English teachers to exchange teaching communication. This paper probes into the factors that influence the connection between junior high school English teaching and senior high school English teaching, and explores how to deal with the connection in English teaching between junior and senior high schools from four aspects, such as, psychological guidance, teaching strategies, learning strategies and evaluation methods.

Exploration of Arabic reading, in terms of the vocalization of the text form by registering the eyes movements of pupils

The intrinsic factors such as the visual constraints, extrinsic such as biomechanics, interface such as the support: the writing, the linguistics, the typography, the sense of progress of the language, have their impact on the habit, and the fittest and particularly the efficiency in reading. We suspect that circuits and zones involved in horizontal orientation “right to the left” are not the same the other way around hanging the linguistic collection. Reading Arabic provided with a specific difference in vocalization proves to be a valuable model verification two major issues which arouse language perception: [lexical processing: is it instantaneous (visual memory) or delayed (memory-tampon)? ···]. And a comparison with other models of language detection mechanisms and brain areas mnemonics which is involved in making information. Results are significatively: children vocalized mode is best seen. It must extend the duration of the mode without vowels. In our opinion, our study is original, and we introduced what a valuable tool in the diagnosis of visual and cognitive strategy by the biotechnology technical based on variations in terms of reading. This opens a horizon of opportunity for the application of the method to the Arabic language to determine the differences in eye size reflecting the effects of task variables in reading and a comparative study of other languages.

Exploration of Teaching Methods in English Reading Lessons

With the increasing of globalization on social life and economic activities,English has already become one of the basic and essential accomplishments for citizens all over the world.English education,in five-year higher vocational education,not only need adapt to the requirements of social and economic development,giving service in order to cultivate high-quality and high-skilled talents,but also should consider students' mental and emotional attitude as well as other factors,thereby meeting their stainable needs in employment and life after graduated.Therefore,the English education of five-year higher vocational education possesses multiply social and cultural significance.Though the analysis and understanding of the course objectives,ideas,contents and implementation suggestions brought up by The English Curriculum Standards of the Five-year Higher Vocational Education in Jiangsu Province,this paper explores the educational methods of higher vocational English reading lessons.

STUDY OF OPTIMAL SLIDING-MODE GUIDANCE LAW

An optimal guidance law based on missile-target line-of-sight (LOS) angular rate is presented for intercepting a nonmaneuvering target. It is then integrated with sliding-mode control theory by using reaching-law of sliding-mode, in order to derive an optimal sliding-mode guidance law for intercepting a maneuvering target. The new guidance method's robustness against target maneuvers and good miss distance performance are proved by the second method of Lyapunov and simulation results. The presented guidance law is simple to implement in practical applications.

An Experimental Method to Read Novels Without Literary Criticism

Though novel reading is a common experience to everybody,little has been researched to help average readers to understand a novel.In practice,there are two ways for them to understand a novel:one is to use literary criticism theories and the other is to refer to professional critics'criticism directly.However,the trouble is that the two methods are either time-consuming or far from convincing.In this paper,an experimental reading method is discussed to help average readers enhance reading experience.It aims at reaching the goal of reading without criticism,which,through making clear the aim of reading,putting main focus on the story only,will help readers to have a better understanding of reading.