Summary of the thesis Theory and Method of Math Teaching: Teaching Mathematics for high school students majoring in physics, chemsitry, biology in orientations towards improving

Purposes of the study: Introduce and clarify the concept the competency of exploring and obtaining knowledge through elemental competencies and compatible activities in teaching maths for high school students; Find out the reality and need of improving the competency of exploring and obtaining knowledge in teaching maths for high schools students majoring in physics, chemistry and biology; Build and test the feasibility of pedagogy method applied in teaching maths at high school classes majoring in physics, chemistry, and biology to foster this capacity for students.

MINISTRY OF EDUCATION & TRAINING

VINH UNIVERSITY

-

NGUYEN TRAN LAM

TEACHING MATHEMATICS FOR HIGH SCHOOL STUDENTS MAJORING IN PHYSICS, CHEMISTRY, BIOLOGY IN ORIENTATIONS TOWARDS IMPROVING THE COMPETENCY

OF EXPLORING AND OBTAINING KNOWLEDGE

Major: Theory and Method of Math Teaching

SUMMARY OF THE THESIS

NGHE AN – 2019

The dissertation is finished at:

Vinh University

Names of supervisors:

1 Dr Nguyen Van Thuan

2 Prof Dr Dao Tam

Reviewer 1: Assoc Prof Dr Tran Kieu

Reviewer 2: Assoc Prof Dr Vũ Vu Duong Thuy

Reviewer 3: Dr Thai Huy Vinh

The research will be defened at Ministerial Thesis Evaluation

Committee held at Vinh University

Time: , date: month year 2019

The Thesis can be found at:

- Vietnam National Library

- Vinh University Library

INTRODUCTION

1 Justification of the study

1.1 Nowadays the educational systems of all countries in the world have been

facing challenges and practical requirements: being required to actively innovate to catch up with current changes because of the rapid development of technology, and the growth in the quantity and quality of human knowledge The distance between theory and practice is on the increase, so the task of Education and Training (ET) is said to create active students Together with the orientation towards action, the orientation of developing ability has been able to fulfill this important task

1.2 The concep “ability”, especially the term “ability of teaching maths”

have been found in many researches in Vietnam and in the world However, the topic Developing the competence of exploring and obtaining knowledge in teaching maths for students, especially at high school level, has not been deeply studied In fact, there are not any studies of teaching maths for high school students oriented towards improving the competency of exploring and obtaining knowledge

1.3 The students majoring in physics, chemsitry and biology are chosen to take

part in this research since practical surveys have found that these students have a habit of studying and discovering new things, and they are often interested in what they studied by themselves Moreover, the students majoring in physics, chemistry and biology are usually eager to learn maths as it is considered as a good tool to support them to studies their majors more effectively

1.4 The concept Teaching maths through activities, which can shape and

develop ability, have been researched by a large number of educators Innovating teaching method towards learner-centered has been implemented in schools Intuitively, the term "the competency of exploring and obtaining knowledge" more or less expresses the ambition as well as active participation of learners in approaching and mastering the knowledge

Basing on theoretical and practical basis, the paper has set requirements and facilitated the research on ability of discovering and acquiring knowledge on the basis of giving conception, proposing pedagogy methods to foster this capacity in teaching maths at high school and the gifted high schools

2 Purposes of the study

2.1 Introduce and clarify the concept "the competency of exploring and

obtaining knowledge" through elemental competencies and compatible activities in teaching maths for high school students;

2.2 Find out the reality and need of improving the competency of exploring and

obtaining knowledge in teaching maths for high schools students majoring in physics, chemistry and biology;

2.3 Build and test the feasibility of pedagogy method applied in teaching maths

at high school classes majoring in physics, chemistry, and biology to foster this

capacity for students

3 Scientific hypothesis

Basing on the research to identify the elemental capacity of the ability of creativity and the knowledge –grasping competennce, if methods can be given to create effective teaching activities for the high school students majoring in physics, chemistry and biology, they can improve the competence of discovering and the knowledge –grasping competence Besides, it can boost the effectiveness of teaching maths at the gifted high schools

4 Research task: The thesis will answer the following questions

Questions 1: What are the viewpoints of researchers in regard to the topic of this

thesis? What are the reasons to choose the topic?

Questions 2: What are activities or cognitive activity defined? What are definitions

of discovery activities and knowledge acquisition; discovery competence and knowledge acquisition? How can compatible activities of the elemental ability, and its levels be displayed?;

Questions 3: What are characteristics of the high shcool students majoring in

physics, chemistry and biology? What are the method of teaching maths suitable for encouraging these students to improve the competency of exploring and obtaining

knowledge?;

Questions 4: What is the reality of improving discovery ability and the competency

of exploring and obtaining knowledge in teaching maths for high school students majoring in physics, chemistry and biology? What are the reasons and solutions of

this issue?

Question 5: How is the discovery ability and knowledge acquisition of the students

majoring in physics, chemistry and biology improved after being taught maths basing suggested methods in the thesis? What are the results of pedagogical experiment?

6.1.1 The paper has introduced the connotation concept of the term discovery

activity and knowledge acquisition; discovery ability and knowledge acquisition as well as elemental ability and its levels in teaching maths for the high school students

in general and the gifted high school students in particularly

6.1.2 The paper has given directions and six pedagogical measures to improve

the competency of exploring and obtaining knowledge for the students through teaching maths

6.2 Practical viewpoints

6.2.1 The paper has built learning topics that can be used in teaching maths to

improve the competency of exploring and obtaining knowledge for the students majoring in physics, chemistry and biology at the gifted high schools

6.2.2 The paper has initially tested the feasibility of the pedagogical measure

built through pedagogical experiments and expected to be successful to be implemented on a large scale

6.2.3 The paper can be used as a reference for math teachers, which aims to

improve the effectiveness of teaching maths at high schools and gifted high schools

7 The contents of the paper defended

7.1 Viewpoints on improving the competency of exploring and obtaining

knowledge based on elemental competencies in teaching maths for gifted high school students (these elements are really necessary and can be transfered to students in teaching maths at high schools)

7.2 The system of proposed measures in teaching maths is appropriate and

feasible in training compatible activities to improve the competency of exploring and obtaining knowledge for high school students in general and high school students majoring in physics, chemistry and biology in particularly

7.3 Some developed teaching topics connect with the use of pedagogical

measures proposed by the thesis are specific ways to improve the competency of exploring and obtaining knowledge in teaching maths at the gifted high schools

8 Design of the paper

In addition to the Introduction and Conclusion, the paper consists of three chapters

Chapter 1 Literature review

Chapter 2 Some pedagogical measures to improve the competency of

exploring and obtaining knowledge for high school students majoring in physics, chemistry and biology

Chapter 3 Pedagogical experiment

CHAPTER 1: LITERATURE REVIEW

1.1 Overview

1.1.1 Competence

1.1.1.1 Previous studies in the world

Perrenoud's definition of competence can be considered to be the most meaningful andaccurate among given definitions of this concept According to Perrenoud, a competence is the ability to act before an assumption, the situation that someone can master because they have both the requisite knowledge and the ability

to consciously mobilize this knowledge to identify and solve real problems [62]

1.1.1.2 Previous studies in Vietnam

There are some main characteristics in studies of competence Firstly, the ability express individual psychological, physiological characteristics that are different from that of a biological genetically inherited factor, developed or limited due to other conditions of the habitat Secondly, the ability or competence is not only an innate factor, but also develops in activities, by activities, exists and manifests itself in activities of individuals In other words, the term “competence” should be mentioned

in a specific type of activity

1.1.2 Studies relating to the thesis topic

With regard to effect of teaching through discovery activities, there were a large number of researches by researchers, such as Heather C Hill, Merrie L Blunk, Charalambos Y Charalambous, Jennifer M Lewis, Geoffrey C Phelps, Laurie Sleep

& Deborah Loewenberg Ball, [206] Besides, Martin C Libicki, Stuart E Johnson [209], indicated important roles and trends in improving the knowledge- grasping competence while Daeka [169] studied the model that was based on experience and collaboration in work group to develop the creativity of students J Bruner [164] studied teaching basing on discovering and methods of discovery activities; Malin Brännback, Patricia Wiklund[211] studied principles of improving the knowledge – grasping competence; and Peter Sullivan [214] refered teaching maths by owning the knowledge

In Vietnam, Nguyen Huu Hau [62] has researched activities to dominate knowledge in teaching Algebra and Calculus The authors Dao Tam and Le Hien Duong [112] mentioned knowledge -grasping competence in general and proposed some pedagogical measures to support students to develop this capacity in teaching elementary geometry at the University of Pedagogy However, there have not been any researches

on improving the knowledge – grasping competence, which can be studied in full and in detail, especially in term of teaching for high school students majoring in physics, chemistry and biology basing on this orientation

1.1.3 Teaching perspective-oriented capacity development

1.1.3.1 In the world

Teaching from the perspective of capacity development has been paid attention

to and conducted in many nations in the world because it not only encourages students to concentrate on intellectual activities but also enhances them to develop problem - solving skills within situations of life and career; it can also link intellectual activities with practical activities Summarizing theories on competency-based teaching approaches in education, training and development, Paprock (1996) outlined five basic characteristics of this approach Firstly, competency-based approach on the learner's philosophy is the center Secondly, competency-based approach meets the requirements of professional activities Thirdly, competency-based approach is oriented to real life and real career activities Fourly, competency-based approach is very flexible and dynamic Finally, competency-based approach is formed in learners clearly

1.1.3.2 In Viet Nam

In summary, there are several core factors of the teaching from the perspective

of capacity development: Teachers organize activities to promote positive and proactive learning of students; create a supportive learning environment (linked to the real context); encourage students to reflect ideas and actions, encourage communication; enhancing the learning responsibilities of learners; creating favorable conditions for learning, sharing, exchanging, debating, connecting to learning; provide full opportunities for learners to explore, experience and create; and teaching

is like a learner's learning process

1.2 Improving the competency of exploring and obtaining knowledge

1.2.1 Activity and cognitive activity

1.2.1.1 Activity

An activity includes folowing characteristics Firstly, it always has objects and it

is done by a subject Moreover, it always has its own purpose, and can operate

according to indirect principles According to A N Leonchev [82, p 579], activity is

a process of performing the mutual exchange between two poles: the subject - the object The author described the macro structure of the activity with 6 components that have dialectical relationship with each other

1.2.1.2 Cognitive activity

The term Cognitive activity is defined as the following basic characteristics Initially, it is the subject of discovering and recreating the world, thereby forming and developing the understanding of subject of the world and its methods of movement The subject does not directly affect objects but indirectly through labor tool The Cognitive activity often takes place in direct or indirect interactions between individuals It is said to have many levels, which depends on the involvement of both cognitive and rational cognitive functions It is a dynamic, positive and creative process of the subject; which starts from unknown to knowing, from superficial to internal attributes, that is, from sensory, intuitive, separate to the complete, stable, regular, and deeper substance of a whole class of objects, phenomena and finally return to reality Cognitive activities in general and mathematical cognitive activities

in particular have three levels, which includes being aware of the problem, understanding and clarifying it

1.2.2 Activity of exploring and obtaining knowledge

We propose the concept of connotation of the concept of discovering and acquiring knowledge in accordance with that satisfies students' requirements to

positively study learning as the following viewpoints Discovering and acquiring knowledge is a series of activities that actively experience, discover, think, attempt, and use intellectual abilities (observation, comparison, analysis, synthesis and experience, verification ) along with personal qualities such as desire for learning, perseverance, flexibility, critical thinking as well as endurance towards issues that need to be addressed without specific knowledge, to capture and master the problem more fully, to be more independent, creative as well as to gradually expand it with related issues, adding to their existing knowledge Thus, it can be understood that

discovering and acquiring knowledge is a sequence of activities done by the subject, which can transform the logic of the object into the thinking process due to the subject’s active, positive participation; thereby grasping, mastering, thoroughly understanding the subject and including the expansion of research and mastering of other related subjects Discovery not only indicates what exists inside each object or phenomenon of the problem, but also shows an extension of the mastery of the subject being studied beyond what is inside the thing, the phenomenon of that problem

1.2.3 The role and meaning of organizing activity of improving the knowledge – grasping competence for students in teaching maths

According to B Maskey, J Collum: concept card (Nepal Training Institute), using verbal methods and encouraging student self-organization, combining methods

to mobilize multiple senses at the same time to participate in the learning process is limited Studies show that students want to gain in-depth understanding and long-term memory, it is important to encourage them to participate in activities directly because, they will be able to use the acquired knowledge in a better way due to their

own experience This can make the process of discovering and acquiring knowledge more fully and deeply Moreover, it is essential to give students joy and excitement because it is the motivation to promote their self-discipline and positive learning, especially the joy and excitement of a person who finds the truth on his own It is said that students should be put into real-world situations, and required to directly observe and make experiment, discuss and to solve problems in their own way Thereby, students will acquire new knowledge, learn new skills and methods as well as find out that knowledge and skills do not necessarily have to follow the existing patterns

to reveal their potential creation [12, p 3]

1.2.4 The concept of improving the competency of exploring and obtaining knowledge

From psychology and education perspectives, from studies on activities, awareness, competence, which are being applied in teaching mathematics at high schools, and the concept that considers discovering and acquiring knowledge as an

important competence to be develop, the competency of exploring and obtaining knowledge can be defined as personal psychological characteristics, through a combination of elemental competencies expressed in activities of individuals in order to actively explore, comprehend, master and address concerned issues flexibly and creatively

1.3 Expression and elemental competencies, as well as compatible activities

of the competence of exploring and obtaining knowledge in teaching maths

The ability of discovering and acquiring knowledge of students in learning maths can be evaluated according to the following criteria Firstly, they can Mobilize math knowledge related to discovering and mastering a specific math content Secondly, they can be able to conduct activities such as doing exercises, understanding mathematical concepts and proving theorems properly, and gaining results consistent with required purposes For example, in proving the theorem, students' ability to discover and gain knowledge is shown through their understanding

of theoretical proof, independently conducting theoretical proof In addition, learners also know how to apply creatively in many other related exercises, or other topics of which a higher level is applied in life Students have clear attitude and emotions with problem solutions, such as finding mistakes and correcting mistakes, realizing the good and profound sides of each solution Moreover, students learn to be persistent in expanding assignments and problems

The competence of exploring and obtaining knowledge of learners in studying mathematic can be described basing on the following six elemental competencies and

21 suitable activities

1.3.1 The first elemental competence: The ability to experience, explore situations, detect problems, detect contradictions appearing in situations and problems

This component competence includes compatible activities, such as hands-on experience, consideration of ongoing issues It also includes experiencing, discovering signs of nature, general properties as well as mathematical relationships

of things and phenomena Another important characteristic is to limit problems, identify the hypotheses and the conclusions of the theorem, and the relationships of

those elements as well The last point is said to discover and detect contradictions that appear in the problem

1.3.2 The second elemental competence: The ability to observe, intuitively solve problems, formulate and implement problem solving in common logic ways for similar problems

This component competence includes compatible activities, such as discover and detect visual symbols and their relationship that appears in the problem and know how to choose good images to support the problem domination The second criterion

is to analyze and explore knowledge through research and observation of visual images or animation Besides, it is necessary to make good use of the mathematical software or visual images, which can create symbols and images relating to the problem as well as point out mistakes to solve them Finally, a suitable approach should be given to solve problems in an appropriate sequence

1.3.3 The third elemental competence: ability to predict and infer reasonably, associate and mobilize knowledge, perform thinking manipulations

in the process of acquiring knowledge

This component competence includes compatible activities, such as making reasonable predictions and inference, selecting reliable predictions Besides, it is required to associate, mobilize knowledge to the "nearest development zone" to facilitate in finding a way to solve the problem Finally, it is essential to implement systematization as well as infer effectively in the process of discovering and mastering the problem

1.3.4 The fourth elemental competence: Ability to use language in mathematical communication

There are some compatible criteria The first requirement is to express mathematics content in different ways accurately to have better access to the problem

to be solved The second requirement is to be able to "interpret" from the common language form of maths clauses to mathematical terms and symbols, and vice versa Thirdly, it is required to use language of set theory and mathematical logic along with mathematical symbols and terminology accurately and rationally to express solutions Moreover, it is necessary to use the right rules of proof, reciprocal clauses Last but not least, it is required to explain the nature of a formula or the final steps of an exercise Below is the example of this competence

Example 1.1 (cited [139, p 109 - 110]) According to the design, the original

height of the Eiffel Tower is 300m, but the antenna mast on the top of the tower increases its height reaching at 325m The lowest temperature in March 2015 in Paris was 8oC on March 1, 2015 and the highest temperature in July 2015 was 26oC and measured on July 18, 2015 Calculate how many centimeters the tower has grown from March to July 2015, assuming the tower is 325 meters tall on March 1

To do this exercise, the students majoring in physics relate and mobilize to the following contents

- Every solids have changes in length because of the change of temperature, which is described by the following formula l = +l0 l0  (t−t0), in which l 0 : The

length of the object at time of temperature t 0; l: The length of the object at time of temperature t; and : Long expansion coefficient

- Students look up the board to find out the length of expansion due to the heat

1.3.5 The fifth elemental competency: Competence in mathematical modeling practical problems

This competence can be showed by the following activities Firstly, It can build mathematical models for practical issues Secondly, it can orient and solve model problems and master practical problems

1.3.6 The sixth elemental competency: critical and creative ability

This ability can be displayed via some compatible activities Firstly, it can collect results of solving problems with right situations and right limits Secondly, it can make comments on problem-solving results, compare problem-solving methods

to choose the best solution Besides, it requires students to adapt and critique in assessing the process of problem-solving, contemplate solutions, detecte and correct mistakes; and solve the problem from a new perspective and expanding

1.4 Levels of improving the competency of exploring and obtaining knowledge

in teaching maths in high school

The competency of exploring and obtaining knowledge is classified according to various levels

*) The first level: Students fulfill the basic requirements of discovering and

acquiring knowledge when situations and issues are clearly raised by teachers

*) The second level: Students have a clear awareness of situations and problems

that are raised by teachers, and they know how to complete improving the knowledge grasping actively and effectively Teachers act as acatalyst to accelerate students' discovery and acquisition of knowledge

*) The third level: Students actively identify unclear issues through activities of

discovering, predicting conditions and commenting on approaches to firmly, flexibly and critically Moreover, by this way, they also know how to expand and master the subject

Below is example showing the levels of improving the competency of exploring and obtaining knowledge

Example 1.2 There is a park showed in Figure 1.1.a It is planned to put a lamppost

to illuminate the park Find an option to locate the lamppost This problem is conducted in the following steps:

+) Step 1: Measuring and simulating the park as Figure 1.1b

+) Step 2: Design a coordinate systerm Oxy as Figure 1.1c, then the coordanetes of

the vertexes of the part are A(0;3), B(4;0) and C(4;7) respectivily Denoting I by the

location where the lamppost is put in to satisfy the condition of the issure

To determine the accurate position of the lamppost, answering the questions below:

1 In your opinion, Where should the lamppost be put? Explaining your choice

A The centriod B The center of The circumcircle

C The Orthocentre D The center of the inscribed circle

2 Depending on your knowledge to determine and expalain the local that the lamppost is put in the picture

In the first level: The probem is very clearly to give for pupils, that contain all steps above, it means that, the pupuls must answer the questions in the step 2 In the second leveli: The problem is quite clearly to give for pipuls, stopping at step 1, then

learners must solve it So, learners have to guess and finish the issure as the step 2

And at the last level: The problem is given without any adding, learners have to solve

the problem by themselves

1.5 Main characteristics of high students majoring in physics, chemistry and biology

1.5.1 Characteristics of intellectual development in high school students

According to the author Pham Sy Nam’s study [90], in regard to practical teaching, there are serveral outstanding characteristics of high school students Firstly, they are intentional, highly purposeful thrive in all cognitive processes Their purposeful knowledge has reached a very high level, and their observation becomes more purposeful, systematic and comprehensive Especially, the observation process

is more controlled by the second signal system and is not separated from linguistic thinking Therefore, it is essential for teachers to pay attention to guide children in a certain task, and not to be hurry to give conclusion without fully accumulating information

1.5.2 Characteristics of high school students majoring in physics, chemistry and biology

These students have a habit of studying and discovering new things, and they are often interested in what they studied by themselves Most of them are good at maths, which are described by the following factors Firstly, they can be able to collect information relating to the problem They can also process the obtained information during solving the problem Additionally, they can have the ability to store mathematical information and have tendency to mathematicalize the phenomena of the surrounding world In other words, these students have the trend of viewing the world "with the eyes of a mathematician" They are always excited and much

A

B O

x y

4 3

7m

3m

4m

interested in experimental activities, simulations to solve practical problems Howver,

in fact they are only good at theory not at experiment or hands-on experience

1.6 The concept of teaching maths for gifted high school studends in orientations toward developing the improving the competency of exploring and obtaining knowledge

Some concepts are approved The first concept is to increase in using centered teaching methods, focusing on experience activities of students The second one is to focus on mathematical modeling activities and practice the language conversion activities in students' maths communication Thirdly, it is essential to promote an individual role in cooperation and group activities, personalizing learners, practicing critical and creative thinking The fourth viewpoint is strengthening interdisciplinary content and topics, creating an E-Learning environment in teaching, linking mathematics with practice, focusing on the role of mathematics in solving practical content Additionally, it is important to create a pedagogical environment with teachers acting as the guiders to adjust and promote students’creativity, and their duties are to focus on organizing activities to promote positive and proactive learning

learner-of students Finally, students should be encouraged to self-study

1.7 The reality of improving the competency of exploring and obtaining knowledge in teaching maths in gifted high schools

1.7.1 Aim: Having investigated the actual situation, a survey of two main

subjects including math teachers and high school students majoring in physics,

chemistry and biology was conducted for the following purposes

For students: Understanding the difficulties of students and their experience

activities in learning maths; learning students' understanding of the relationship between mathematical contents and real life

For teachers: Understanding the difficulties of teachers and students in teaching maths to high school students majoring in physics, chemistry, and biology; Learning about the implementation and viewpoints of maths teaching in particular and teaching

in general according to orientation toward developing competences for the gifted high school students

1.7.2 Surveyed participants: math teachers and students at some gifted high

schools in Nghe An, Ha Tinh, Thanh Hoa, and Hochiminh Gifted school

1.7.3 Surveyed content: Learning about the teacher's understaing of activities;

actual situation of exploitation and operation training; the need of improving and practicing for students the manifesting activities of the ability to discover and

dominate knowledge in learning maths

1.7.4 Method: search and statistic information/data by conducting interviews,

observing classes, questionnaires with subjects that are teachers and students majoring in physics, chemistry, and biology Besides, summarizing experience methods are applied with researching materials related to the teaching situation in gifted high schools

1.7.5 The Findings

1.7.5.1 Qualitative results

a) Students have dfficulties in learning the content of subjects: Because

learners bring incomplete insights into the subject, they often bring the previous

knowledge into the relevant content

b) Some research findings on teachers: straight teachers will greatly influence students' style, ability, and learning outcomes

c) The obstacles from the current textbook program: Author Dao Trong Thi

wrote: “The program and the amount of knowledge shown in the textbooks is too much compared to the understaning of students to Besides, the content puts more emphasis on theory and imparting knowledge without paying much attention to train students' skills and personality” [195]

1.7.5.2 Analysis of quantitative results

Most of surveyed participants (93.8%) find that it is necessary to design and organize activities for students to discover and gain knowledge Only 6.2% of them did not see the need to organize this activity In contrast, 100% of teachers and administrators agree on the necessity of organizing discovery activities and gaining knowledge, and most of teachers and managers are interested in the manifest activities of discovering and acquiring knowledge, but the capacity and organization

of those activities are not equal Students are encouraged to practice activities that are part of the ability to discover and dominate knowledge, but these activities are not conducted regularly It is said that students’ improving the competency of exploring and obtaining knowledge is only at fair level Besides, there are some activities that shows their ability only at average level, accounting for nearly 50% This shows that the capacity to discover and dominate knowledge should be paid attention and continue research Most of students want to be trained in compatible activities to improve the knowledge – grasping competence, but the training of those activities in learning is chaired and controlled by teachers has not been focused properly Teachers and students also think that about 25% -30% of students often face difficulties and passively when actively implementing compatible activities of discovering and acquiring knowledge in the classroom

1.7.6 Cause of the situation

There are some main reasons Firstly, the teacher has not really considered improving the competency of exploring and obtaining knowledge in terms of competencies of component activities, and has not clearly identified the elemental competencies of this capacity, as well as typical manifestations of these competencies

so that activities can be organized in accordance with the teaching content, which aims to formulate and train students' ability to discover and acquire knowledge Secondly, generally teachers have not identified measures and ways to implement measures to improve the competency of exploring and obtaining knowledge in association with the content of maths teaching Finally, teachers have difficulty identifying and exploring opportunities for students to be experienced, trained, and fostered improving the competency of exploring and obtaining knowledge in the teaching process

1.8 Conclusion of Chapter 1

On the basis of research, analysis and practical experience, in Chapter 1, we

draw some results as follows: Firstly, the thesis has codified the views of a number