KR20210055971A - Online Golf Lesson Service Systems and Methods - Google Patents

Abstract

In accordance with the present invention, in regard to an online golf lesson in a remote place, when a learner performs a golf swing through a golf simulator, golf swing image and voice information of the learner is transmitted as data to an instructor in real time, and then, the instructor checks and analyzes transmitted video data to transmit a correct golf swing posture in image and voice formats to the learner such that the online golf lesson procedure can be performed in real time. In accordance with the present invention, provided are an online golf lesson service system and a method thereof. The system comprises: a learner terminal device and an instructor terminal device configured to transmit and receive an image made by photographing the learner's golf swing posture as an online golf lesson is conducted through first and second golf simulators in a remote place; and a main server connected to the Internet through a web server. The web server includes: a learner management part for the registration and information management of a learner; an authentication processing part performing login and authentication procedures of the learner; and a game proceeding part enabling the learner terminal device to proceed with a golf game. The main server includes: a main management part controlling communication by the web server; a community management part managing login management and website management for the web connection of the learner; and a database building program control with respect to an operation management program of the web server.

Description

Online Golf Lesson Service Systems and Methods

The present invention relates to an online golf lesson service system and method, and more specifically, in conducting an online golf lesson from a remote location, when a learner performs a golf swing using a golf simulation device, the golf swing posture of the learner is determined. Through a real-time two-way communication that allows video and audio information to be transmitted to the instructor by shooting a video, the instructor checks and analyzes the transmitted video data, and transmits the corrected golf swing posture to the instructor in video and audio. The present invention relates to an online golf lesson service system and method for effectively performing an online golf lesson process.

In general, online golf lessons correspond to a kind of video education, which means an educational method that is conducted without time and space constraints using information and communication technologies such as the Internet. This is a form of service provided through the Internet after real-time transmission or recording by producing a teaching scene as a video.

However, the online golf lesson method took a method in which the lessons were delivered only in one direction. For example, online lesson providers store content related to the swing posture during a golf game produced in a database server, and only deliver it in one direction through online to certified instructors.

In other words, when an online instructor plays a golf game using a golf simulation device like offline, this is because the instructor could not immediately respond to information on golf correction posture such as swing posture during the golf game. There is a problem in that the reliability of online golf lessons is deteriorated since it did not substantially help to improve the golf lessons of the instructor.

KR 10-1110357 KR No. 10-0627659 KR No. 10-0898317 (Patent Publication No. 0004) KR No. 10-2018-0034195

The present invention is to solve such a problem, and when a golf lesson is conducted online at a remote location, but mutual matching is made through a message between the instructor and the instructor, and the terminal device of the learner is activated through the authentication process of the web server, When the student's golf swing is progressing using the golf simulation device of the learner's terminal device, the first video recording unit captures a video of the golf swing posture, and the golf swing image is displayed through the first display unit, and the video and audio information is displayed by the first video processing unit. After the information is generated as data, data is transmitted to the instructor through the first data communication unit, and the instructor checks and analyzes the golf swing image of the instructor through the second display unit, and then the corrected golf swing posture by the instructor is removed. 2 It is to provide a line golf lesson service system and method in which lessons are taken through a real-time two-way communication that is photographed by a video recording unit and transmitted to the learner in video and audio through a second video processing unit and a second data communication unit.

The present invention provides a golf lesson using a golf simulation device of a learner online at a remote location, but the golf swing posture is photographed and transmitted and received as an image. The learner's terminal device and the instructor's terminal device are connected to the Internet through a web server. With the main server,

The web server includes: a learner management unit for registering and managing information of the learner; An authentication processing unit that performs a log-in and authentication procedure of the learner; It includes a game progress unit to proceed with the golf game by the terminal device of the learner,

The main server may include a main management unit for controlling communication by a web server; A community management unit that manages the web site and login management for the learner's web access; It features an online golf lesson service system including; a database in which a program control is established for an operation management program of a web server.

The learner's terminal device uses a first golf simulation device to capture a golf swing image from various angles while a golf swing is in progress, but the captured image is applied to a first image processing unit and a first display unit. 1 video recording unit; A first image processing unit that generates the golf swing image, is displayed on the first display unit, applies it to the first data communication unit, and processes the golf swing image received from a remote instructor terminal device to be displayed in real time; A first data communication unit for transmitting or receiving a swing image and swing data transmitted from the remote instructor terminal device in real time; A first terminal device control unit configured to receive and display a swing image and swing data transmitted from a remote tutor terminal device through the first data communication unit on a first display unit; And a first display unit that displays the swing image and swing data processed by the first image processing unit.

The instructor's terminal device is a second video for capturing a golf swing image from various angles when the instructor's corrected golf swing is in progress in the correction management room, but the captured image is applied to the second image processing unit and the second display unit. Photographing department; A second image processing unit that generates the golf swing image, is displayed on a second display unit, applies it to a second data communication unit, and processes a golf swing image received from a remote learner's terminal device to be displayed in real time; A second data communication unit for transmitting or receiving in real time the swing image and swing data transmitted from the remote learner's terminal device; A second terminal device control unit configured to receive a swing image and swing data transmitted from a remote learner's terminal device through the second data communication unit and display it on a second display unit; And a second display unit that displays the swing image and swing data processed by the second image processing unit.

The correction management room is provided with a second golf simulation device, and the second video recording unit is configured to capture an image of the instructor's corrected golf swing posture using the second golf simulation device.

Preparing an online golf lesson through a message chat between the instructor and the instructor; A step of starting an online golf lesson between the instructor and the instructor when the learner performs a login and authentication procedure to match each other through the Internet; Capturing and generating a golf swing image when a golf swing is progressed using a first golf simulation device in a learner's terminal device; The step of displaying the student's golf swing image on a first display unit and transmitting it to a remote teacher terminal device in real time so that the student's swing image and swing data are displayed on the second display unit; Checking and analyzing the student's swing image and swing data by the second display unit, and then photographing the corrected golf swing posture by the instructor's terminal device; The golf swing posture corrected by the instructor is characterized by an online golf lesson service method comprising: a lesson step performed through real-time communication in which video and audio are transmitted to the instructor.

In the step of starting the online golf lesson, the learner performs a login and authentication procedure through the authentication processing unit of the web server, and when mutual matching is made through the Internet, the instructor terminal device and the instructor terminal device are activated. It is characterized.

In the step of capturing and generating the golf swing image, when a golf swing using the first golf simulation device is performed by the instructor, the golf swing image is photographed from various angles by the first video recording unit, and the first image processing unit It is characterized in that the swing image is generated in

In the step of displaying the learner's swing image and swing data, the first data communication unit of the learner's terminal device transmits the swing image and the swing data to the remote learner's terminal device in real time, and the second terminal device control unit transmits the swing image and swing data in real time. The second display unit is characterized in that the student's swing image and swing data are displayed.

In the step of photographing the corrected golf swing posture, the instructor's swing image and swing data are checked and analyzed by the instructor in the second display unit, and then the corrected golf that the instructor intends to transmit using the second golf simulation device. It is characterized in that the swing posture is photographed and generated by the second video recording unit.

Preparing online golf lessons through message chat between the learner and the instructor: When the learner performs a login and authentication process and mutually matches through the Internet, online golf lessons between the learner and the instructor are provided, but the instructor avoids in advance. Classifying the instructor's golf level by class and opening a lesson room to start an online golf lesson; An image of the instructor's swing through the lesson room opened during the golf swing using the first golf simulation device on the student's terminal device Photographing and generating shot data; The step of displaying the student's golf swing image on a first display unit and transmitting it to a remote teacher terminal device in real time so that the student’s swing image and swing data are displayed through the lesson room opened on the second display unit. ; In the second display unit, the instructor confirms and analyzes the student's swing image and swing data through the opened lesson room, and then photographs the corrected golf swing posture in the instructor terminal device; The online golf swing posture corrected by the instructor is transmitted to the instructor in video and audio, but the instructional instruction for selecting the continuously repetitive swing posture and target point and club is taught through real-time communication. It features a lesson service method.

In the present invention, when mutual matching is made through a message between the instructor and the instructor at a remote location, the instructor passes through the authentication process of the web server, and the instructor shoots a video while the golf swing is in progress using a golf simulation device and transmits data to the instructor in real time. After this, the instructor checks and analyzes the video of the instructor's golf swing, and then the corrected golf swing posture by the instructor is transmitted to the instructor through video and audio. You can effectively proceed the golf lesson process up to the master.

In addition, the present invention is online in real time while visually checking shot data (speed, height angle, left and right angle spin, head speed, etc.) during a golf swing using a learner's terminal device and an instructor's terminal device if only the Internet is connected. Since you can do golf lessons, there is an effect that you can do golf lessons without being restricted by time or place.

In addition, the present invention provides real-time communication, such as opening a lesson room in which the class of the instructor's golf level is classified, and preemptively or afterwards, the target point and club selection guidance according to the hole to be played on the field through screen golf. Through this, there is an effect of being able to teach such as teaching golf directly on the field.

1 is a block diagram showing an online golf lesson service system according to the present invention.
Figure 2 is a block diagram showing step by step an online golf lesson service method according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted.

The online golf lesson service system according to the present invention includes a learner's terminal device 30 and a learner's terminal in which a golf swing posture is photographed and transmitted and received as an image during a golf lesson using a golf simulation device of a learner online at a remote location. The device 40 is provided with a main server 10 connected to the Internet through the web server 20 so that a golf lesson is performed through real-time communication between the instructor and the instructor.

The web server 20 includes a learner management unit 21 for registering and managing information of the learner; An authentication processing unit 22 that performs a log-in and authentication procedure of the learner; It consists of a configuration including a game progress unit 23 to allow the golf game to proceed by the learner's terminal device 30.

The main server 10 includes a main management unit 11 for controlling communication by the web server 20; A community management unit 12 for managing a web site and managing a login for a learner's web access; It has a configuration including; a database 13 in which program control for the operation management program of the web server 20 is built.

The tutor terminal device 30 and the tutor terminal device 40 include: first and second video recording units 34 and 44; First and second image processing units 33 and 43; First and second data communication units 32 and 42; First and second terminal device controllers 31 and 41; First and second display units 35 and 45; respectively.

In addition, an image (including audio) photographing a golf swing posture using the first golf simulation device (A) during a golf lesson of the instructor, or shot data (speed, height angle, left and right angle spin, head speed, etc.) ) Is applied to the learner's terminal device 30, but the golf simulation device (A) is installed to be interlocked with the learner's terminal device 30 so that overall golf lessons from the introductory golf course to the master course can be conducted.

In addition, the instructor performs a golf lesson in which the corrected golf swing posture is transmitted to the instructor in video and audio without using a golf simulation device in the correction management room (C), and a second golf simulation device ( After B) is provided, golf lessons can be performed using the second golf simulation device B, and at this time, the instructor's second golf simulation device B is installed to be interlocked with the instructor terminal device 40.

The first video recording unit 34; During the golf swing process using the first golf simulation device (A) of the learner, the golf swing image is photographed from various angles, and the image captured by the first video photographing unit 34 is a first image processing unit 33 ) And the first display unit 35.

In addition, the second video recording unit 44; An image of the instructor's corrected golf swing posture is taken, and the image captured by the second video recording unit 44 is applied to the second image processing unit 43 and the second display unit 45, and the second It goes without saying that even when the golf simulation device B is used, the process of capturing an image and applying it to the second display unit 45 is performed in the same manner.

The first image processing unit 33; The golf swing image is generated and displayed on the first display unit 35, is applied to the first data communication unit 32, and the golf swing image received from the remote instructor terminal device 40 can be displayed in real time. Processing, the first data communication unit 32; A swing image (including audio) and swing data transmitted from the remote instructor terminal device 40 are transmitted or received in real time.

The first terminal device control unit 31; Controls to receive and display the swing image and swing data transmitted from the remote instructor terminal device 40 through the first data communication unit 32 on the first display unit 35, and the first display unit 35 Is; The swing image and swing data processed by the first image processing unit 33 are displayed.

The first image processing unit 33; A golf swing image can be generated and displayed on the second display unit 45, applied to the second data communication unit 42, and displayed in real time, the golf swing image received from the learner's terminal device 30 at a remote location. and processing to the second data communication unit 42 is a swing image (including audio), and swing data transmitted from the gyoseupja terminal device 40 of the remote location is transmitted or received in real time.

The second terminal device control unit 41 receives the swing image and swing data transmitted from the remote learner terminal device 30 through the second data communication unit 42 and displays it on the second display unit 45. And the second display unit 45; The swing image and swing data processed by the second image processing unit 43 are displayed.

A detailed description of a golf lesson service method using the online golf lesson service system configured as described above is as follows.

First, an online golf lesson is prepared through a message chat between the instructor and the instructor, and then the instructor performs a log-in and authentication procedure, and when mutual matching is established through the Internet, the online golf lesson between the instructor and the instructor starts. When the golf swing is performed using the student simulation device by means of the instructor, the golf swing image of the instructor is photographed and generated, displayed on the first display, and transmitted in real time to the terminal device of the instructor at a remote location to the learner on the second display. The swing image and swing data of

When the analysis is completed by checking and analyzing the student's swing image and swing data by the instructor in the second display unit, a golf lesson corrected by the instructor is performed, but the corrected golf swing posture is photographed on the instructor terminal device, and then corrected. The golf lesson that has been completed is a golf lesson through real-time communication that is transmitted to the learner through video and audio. This is a golf lesson in the following process.

That is, the present invention prepares an online golf lesson through a message chat between the instructor and the instructor in the step (S1) of preparing an online golf lesson, which is provided with an online lesson system that enables online golf lessons by the instructor. In this state, through a message chat (application through wired, wireless phone, text, etc.) between the instructor and the instructor, a mutual 1:1 match is made to receive online golf lessons including various golf swing postures.

Subsequently, in the step (S2) of starting the online golf lesson, the instructor logs in through the authentication processing unit 22 of the web server 20 in a state in which the instructor and the instructor are ready to do the online golf lesson through message chat. And when mutual matching is completed through the Internet by performing the authentication procedure, the instructor terminal device 30 and the instructor terminal device 40 are activated and start an online golf lesson between the instructor and the instructor.

In the step (S3) of photographing and generating the golf swing image of the learner, when the golf swing using the first golf simulation device A is performed by the learner who wants to receive the golf lesson, the learner's terminal device ( The golf swing image of the learner is photographed from various angles by the first moving image photographing unit 34 of 30), and the first image processing unit 33 generates a swing image.

In the step (S4) of displaying the student's swing image and swing data on the second display unit provided in the remote teacher's terminal device, the first video recording unit 33 of the learner's terminal device 30 takes a picture. The swing posture image of the learner is controlled to be displayed on the first display unit 35 by the first terminal device control unit 31 so that the learner can directly check the swing posture, etc. through the first display unit 35. do.

In addition, the swing posture image of the learner captured by the first video photographing unit 33 is transmitted to the learner's terminal device 40 at a remote location by the first data communication unit 32 of the learner's terminal device 30. The data is transmitted so that the second terminal device control unit 41 displays the learner's swing image and swing data on the second display unit 45.

In the step (S5) of photographing the corrected golf swing posture that the instructor wants to transmit in the instructor terminal device, the instructor's swing image and swing transmitted to the instructor terminal device 40 and displayed on the second display unit 45 The data can be checked and analyzed by the instructor, and the instructor takes a golf lesson based on the instructor's swing image and swing data, but the corrected golf swing posture that the instructor wants to convey is the instructor's terminal device (40). The second video photographing unit 44 photographs and generates it.

In the step (S6) in which the corrected golf swing image is transmitted in real time to the learner as video and audio, the golf swing image corrected by the instructor is a second image processing unit 43 and second data of the instructor terminal device 40. An online golf lesson is performed through real-time communication between the learner and the instructor as a means to transmit the video and audio through the communication unit 42 to the instructor terminal device 40 of the instructor in real time.

On the other hand, as another embodiment of the present invention, golf lessons are provided through real-time communication between the instructor and the instructor by steps S1 to S6 as described above, but the instructor (professional) is avoided in consideration of the convenience and effect of the lesson in advance. After classifying the instructor's golf level into high, middle, low, etc., a lesson room (golf lesson room) suitable for the instructor's current handiness is opened.At this time, the lesson room may be an 18-hole golf course that is normally played in screen golf. In addition, after selectively opening a golf course consisting of a few separate golf courses with only a few holes, such as par 4, par 5, and par 3, online golf lessons are started between the instructor and the instructor.

In addition, the instructor checks the student's swing image and shot data through the opened lesson room, analyzes and corrects it, and delivers it to the instructor in real time. It is possible to do it repeatedly, and it is of course possible to provide guidance such as selection of target points and clubs according to the holes (par 3, 4, 5) that appear on the screen golf screen to be played additionally.

In addition, the instructor directly checks the left and right dogleg course displayed on the screen golf screen and the swing posture according to the position of the ball, while giving the instructor the course strategy and preemptive instruction on the swing posture, or post-correction while the trainee is swinging. In this way, it is possible to teach through real-time communication, such as receiving guidance from the instructor with instructions on how to operate the course, such as the attack direction, taking into account the terrain and distance of the hole that the learner wants to play, and the difficulty of the hole. .

As described above, in the present invention, when a golf lesson is conducted online at a remote location, but when mutual matching is made through a message between the instructor and the instructor, the instructor terminal device and the instructor terminal device are activated through the authentication process of the web server. In addition, the instructor uses a golf simulation device to shoot a video while the golf swing is in progress and transmits data to the instructor in real time, and the instructor checks and analyzes the golf swing image of the instructor, and then the golf swing posture corrected by the instructor. Through real-time two-way communication that transmits video and audio to the learner, it has the same effect as performing golf lessons on site.

In other words, the present invention is a real-time bi-directional that can check and correct shot data (speed, height angle, left and right angle spin, head speed, etc.) during a golf swing using the instructor terminal device and the instructor terminal device if only the Internet is connected. Through communication, you will be able to do golf lessons.

In addition, by opening a lesson room that categorizes the class of the learner's golf level, through screen golf, you can preemptively or follow the instruction of targeting points and club selection according to the hole you want to play on the field. You will be able to teach the same as teaching golf yourself.

In the above, the present invention has been described with reference to the above embodiments, but it is of course possible to implement various modifications within the scope of the technical idea of the present invention.

10: main server 11: main management unit
12: Community Management Department 13: Database
20: web server 21: instructor management department
22: authentication processing unit 23: game progress
30: learner terminal device 31: first terminal device control unit
32: first data communication unit 33: first image processing unit
34: first video recording unit 35: first display unit
40: learner terminal device 41: second terminal device control unit
42: second data communication unit 43: second image processing unit
44: second video recording unit 45: second display unit
A: 1st golf simulation device B: 2nd golf simulation device
C: Instructor Management Office
S1: Steps for preparing an online golf lesson between the instructor and the instructor
S2: Steps to start an online golf lesson between the instructor and the instructor
S3: Step of photographing and generating a golf swing image in the learner's terminal device
S4: The step of transmitting the golf swing image of the learner to the teacher's terminal device at a remote location in real time so that the swing image and swing data are displayed.
S5: Step of photographing the corrected golf swing posture in the instructor terminal device
S6: The corrected golf swing video is transmitted in real time to the learner in video and audio

Claims (10)

The instructor terminal device 30 and the instructor terminal device 40, in which golf lessons are performed using the instructor's golf simulation device online at a remote location, but the golf swing posture is photographed and transmitted and received as an image, are web server 20 With the main server 10 connected to the Internet through,
The web server 20,
A learner management unit 21 for registration and information management of the learner; An authentication processing unit 22 that performs a log-in and authentication procedure of the learner; It includes a game progressing unit 23 to allow the golf game to proceed by the learner's terminal device 30,
The main server 10,
A main management unit 11 for controlling communication by the web server 20; A community management unit 12 for managing a web site and managing a login for a learner's web access; An online golf lesson service system comprising: a database (13) in which program control for an operation management program of the web server (20) is built.
The method of claim 1,
The learner's terminal device 30,
The first golf simulation device (A) is used to capture a golf swing image from various angles while the golf swing is in progress, but the captured image is applied to the first image processing unit 33 and the first display unit 35 A first motion picture photographing unit 34 to be used;
The golf swing image is generated and displayed on the first display unit 35, is applied to the first data communication unit 32, and the golf swing image received from the remote instructor terminal device 40 can be displayed in real time. A first image processing unit 33 that processes so as to be processed;
A first data communication unit 32 for transmitting or receiving a swing image and swing data transmitted from the remote teacher terminal device 40 in real time;
The first terminal device control unit 31 for controlling to receive and display the swing image and swing data transmitted from the remote instructor terminal device 40 through the first data communication unit 32 and display it on the first display unit 35 ;
And a first display unit (35) for displaying the swing image and swing data processed by the first image processing unit (33).
The method of claim 1,
The instructor terminal device 40,
In the correction management room (C), the golf swing image is photographed from various angles when the instructor's corrected golf swing is in progress, but the photographed image is applied to the second image processing unit 43 and the second display unit 45. A second video recording unit 44;
The golf swing image is generated and displayed on the second display unit 45, is applied to the second data communication unit 42, and the golf swing image received from the learner terminal device 30 at a remote location is displayed in real time. A second image processing unit 43 for processing to be performed;
A second data communication unit 42 for transmitting or receiving a swing image and swing data transmitted from the remote learner's terminal device 30 in real time;
A second terminal device control unit 41 that receives the swing image and swing data transmitted from the remote learner's terminal device 30 through the second data communication unit 42 and displays it on the second display unit 45 );
And a second display unit (45) for displaying the swing image and swing data processed by the second image processing unit (43).
The method of claim 3,
The correction management room (C) is equipped with a second golf simulation device (B), and the second video recording unit 44 captures images of the instructor's corrected golf swing posture using the second golf simulation device (B). Online golf lesson service system, characterized in that to be built.
Preparing an online golf lesson through a message chat between the instructor and the instructor (S1);
The step of starting an online golf lesson between the learner and the instructor when the learner performs a login and authentication procedure to match each other through the Internet (S2);
Capturing and generating a golf swing image when a golf swing is progressed using the first golf simulation device in the learner's terminal device (S3);
The step of displaying the instructor's golf swing image on a first display unit and transmitting it to a remote instructor terminal device in real time so that the student's swing image and swing data are displayed on the second display unit (S4);
Checking and analyzing the student's swing image and swing data in the second display unit, and then photographing the corrected golf swing posture in the instructor terminal device (S5);
The golf swing posture corrected by the instructor is a lesson step (S6) performed through real-time communication in which video and audio are transmitted to the instructor.
The method of claim 5,
In the step of starting the online golf lesson,
The online golf lesson service method, characterized in that when the learner performs a log-in and authentication procedure through an authentication processing unit of a web server and mutually matches through the Internet, the instructor terminal device and the instructor terminal device are activated.
The method of claim 5,
In the step of photographing and generating the golf swing image,
Online golf, characterized in that when the instructor proceeds with the golf swing using the first golf simulation device, the first video capture unit captures the golf swing image from various angles, and the first image processing unit generates the swing image. How to service lessons.
The method of claim 5,
In the step of displaying the learner's swing image and swing data, the first data communication unit of the learner's terminal device transmits the swing image and the swing data to the remote learner's terminal device in real time, and the second terminal device control unit transmits the swing image and swing data in real time. An on-line golf lesson service method, characterized in that a second display unit displays the instructor's swing image and swing data.
The method of claim 5,
In the step of photographing the corrected golf swing posture,
In the second display unit, the instructor's swing image and swing data are checked and analyzed by the instructor, and then the corrected golf swing posture that the instructor wants to transmit is photographed and generated by the second video recording unit using the second golf simulation device. Online golf lessons service method, characterized in that to.
Preparing an online golf lesson through a message chat between the instructor and the instructor (S1-1);
When the learner performs the login and authentication process, and the match is made through the Internet, online golf lessons are provided between the learner and the instructor, but the instructor classifies the level of the instructor's golf level in advance and opens a lesson room to provide online golf lessons. Starting step (S2-1);
Capturing an image of a student's swing through a lesson room opened during a golf swing using the first golf simulation device in the learner's terminal device and generating shot data (S3-1);
The step of displaying the student's golf swing image on a first display unit and transmitting it to a remote teacher terminal device in real time so that the student’s swing image and swing data are displayed through the lesson room opened on the second display unit. (S4-1);
In the second display unit, the instructor checks and analyzes the student's swing image and swing data through the opened lesson room, and then photographs the corrected golf swing posture in the instructor terminal device (S5-1);
A lesson step (S6-1) of transmitting the golf swing posture corrected by the instructor to the learner in video and audio, but teaching instruction for continuously repetitive swing posture and target point and club selection through real-time communication; Online golf lesson service method comprising a.

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