Java-based distance learning environment for electronic instruments

Abstract

Computer-assisted instruction has been used to assist both teachers and students. Recently, the rapid emergence of the World Wide Web (WWW) and its associated tools have provided educators with an opportunity to incorporate this technology into their courses. The undergraduate students in the Mechanical Engineering Department utilize electronic instruments or mechanical instruments frequently. They learn how to use these instruments primarily through a teacher's oral instructions and demonstration. In this paper, the authors developed a computer-aided instruction (CAI) system consisting of four modules: information module, instrument module, examination module, and frequently asked question (FAQ) module. These four modules were arranged to implement a CAI system for electronic instruments. This system is used to teach students how to use oscilloscopes, function generators, and logic analyzers. The CAI system can be used for distance learning.

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88IEEE TRANSACTIONS ON EDUCATION, VOL. 46, NO. 1, FEBRUARY 2003
Java-Based Distance Learning Environment for
Electronic Instruments
Han-Pang Huang, Member, IEEE, and Chiou-Hwa Lu
Abstract—Computer-assistedinstruction hasbeen usedtoassist
both teachers and students. Recently, the rapid emergence of the
World Wide Web (WWW) and its associated tools have provided
educators with an opportunity to incorporate this technology into
their courses. The undergraduate students in the Mechanical En-
gineering Departmentutilizeelectronicinstruments ormechanical
instruments frequently. They learn how to use these instruments
primarilythroughateacher’soralinstructionsanddemonstration.
In this paper, the authors developed a computer-aided instruction
(CAI) system consisting of four modules: information module, in-
strumentmodule,examinationmodule,andfrequentlyaskedques-
tion (FAQ) module. These four modules were arranged to imple-
ment a CAI system for electronic instruments. This system is used
toteachstudentshowtouseoscilloscopes,functiongenerators,and
logic analyzers. The CAI system can be used for distance learning.
Index
distance learning, internet teaching, WWW.
Terms—Computer-aidedinstruction(CAI)system,
I. INTRODUCTION
R
with an opportunity to incorporate this technology into their
courses. The undergraduate students in the Mechanical Engi-
neeringDepartmentutilizeelectronicinstruments,suchasoscil-
loscopes and function generators, frequently to do experiments.
They learn how to use these electronic instruments primarily
through the instructor’s oral teaching and demonstration. Most
of the time this form of instruction is adequate and repeated. In
order to assist the instructor in teaching undergraduate students
how to use these electronic instruments through the Internet, it
is necessary to design a computer-aided instruction system.
Computer-aided instruction or computer-assisted instruction
(CAI)researchiswidelyusedinengineeringapplications.Many
CAI systems are topic-oriented, and different applications can
be constructed in different ways. Generally, a CAI system can
be constructed asan interactivetutorial system, richingraphics,
audio, or video. In some cases, a CAI system is composed of
simulation programs with many functions to simulate the real
instruments. One kind of CAI system can be thought of as a
tutorial system, which is a guided system to provide well-con-
structed information. Students can use this system to learn how
tousea technicalsystemorhowtooperatean instrument.Susan
and William [1] presented a process for constructing a hyper-
ECENTLY, the rapid emergence of the World Wide Web
(WWW) and its associated tools have provided educators
Manuscript received November 2, 1999; revised April 25, 2002. This paper
wassupportedinpartbyGrantNSC-88–2212-E-002-069fromtheNationalSci-
ence Council, Taiwan, R.O.C.
The authors are with the Robotics Laboratory, Department of Mechanical
Engineering,NationalTaiwanUniversity,Taipei10660,Taiwan,R.O.C(e-mail:
hanpang@ntu.edu.tw).
Digital Object Identifier 10.1109/TE.2002.808271
text system. Burks [2] presented computer-based tutorials and
network-based homework and quizzes. A tutorial system using
artificialintelligencewaspresentedin[3].Someresearchersuti-
lized auxiliary software to enhancetheir tutorial system [4]–[6].
Some provided interactive tutorials for manuals with a user-
friendlygraphical userinterface [7]orwithrichmultimediafor-
mats [8], [9].
Because of the pervasive presence of WWW applications, a
CAI environment was developed via WWW browsers through
the Internet. This CAI system was developed, primarily using
Java language which has the property of cross platform com-
munication and can be embedded in WWW browsers. This CAI
system provides an environment for students to learn the use of
instruments and test themselves using examination programs in
the CAI system. The instructor can acquire information about
the students’ learning status using the CAI server program. In
the CAI system, four modules are developed to complete the
teaching and learning process of the instructors and students.
The four modules consist of an information module, an instru-
ment module, an examination module, and a FAQ module. The
information module provides the course contents. The instru-
ment module is used to practice the functions of the instrument
and can be launched by the information module to reinforce the
instruction. Theexaminationmoduleis used totest studentsand
demonstrate how much they have learned from the CAI system.
The instructor can monitor the examination results of the stu-
dents,andifrequired,revisetheinstructionalcontents.TheFAQ
module gives students a place to post their questions.
II. CAI SYSTEM FOR ELECTRONIC INSTRUMENTS
The way for learning new electronic instruments can be di-
vided into two steps: getting information and using the instru-
ment. First, students get an overview of the instrument from a
manual or classroom instruction. After instruction, students can
practiceon theinstrumenttobecome familiar withits functions,
and use a manual for review. Through practicing, students be-
come more familiar with the operation of an instrument. Then
theycanutilizethisinstrumenttoperformexperimentscorrectly
and more safely.
From the learning procedure discussed above, the modules
of this learning procedure must satisfy two important functions.
The modules must provide the correct information to assist
students in getting necessary information about the instrument.
The instrument manual satisfies this requirement. Second,
the modules must provide simulations of the functions of the
instrument for practicing. That is, the role of the instrument. In
the CAI system, the “information module” helps students get
information about the instrument, and the “instrument module”
0018-9359/03$17.00 © 2003 IEEE
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HUANG AND LU: JAVA-BASED DISTANCE LEARNING ENVIRONMENT89
Fig. 1.CAI learning procedure for the electronic instruments.
provides a practicing environment. In a more complicated
learning process, students may acquire more understanding
of the instrument by asking the teacher questions. Then,
the students can reinforce their learning through exercises
and examinations provided by the teacher. To achieve these
enhancements, the learning procedure should include two
additional modules, i.e., “examination module” and “FAQ
module.” The process for learning the electronic instruments is
shown in Fig. 1.
The CAI system is not intended to be an on-line teacher.
Rather, it is an on-line auxiliary guide that helps students learn
the information the instructor wants to teach, and helps the
teacher administer student data and query students’ learning
progress. The four modules illustrated above are discussed
later.
III. INFORMATION MODULE
The information module arranges the instructional material
of a given topic into a number of learning steps. The topic is
part of the general information about the instrument, which can
be arranged into a step-by-step learning process. In the CAI
system, each step is a web page on the WWW browser through
the Internet, since the CAI system is presented via the WWW.
If necessary, an instrument module composed of a simulation
Java applet program is provided for practicing. Practice can be
learning by trial and observation, but the simulation program is
focusedonaspecifictopicoftheinformation.Whenthelaststep
of the information module is completed, the examination con-
tents are launchedby theexaminationmodule. Theexamination
module acquires the related material concerning this topic from
the WWW server through the Internet and displays it for the
students. When a student completes the examination, the exam-
ination module reports the results to the student, and records
it in the WWW server. Fig. 2 shows a flowchart of the rela-
tionship between the information, instrument, examination, and
FAQ modules.
IV. INSTRUMENT MODULE
The instrument module primarily provides simulation pro-
grams of theinstrument. This module helps students understand
how to use the instrument by trial and observation. It serves as
an assistant to the information module. In order to give students
more understanding, the simulation program of this module fo-
cuses only on the functions of a specific topic.
The instrument module is written in Java programming
language since the CAI content is shown in WWW browsers
throughout the Internet. In order to simulate each specific func-
tion of an instrument in each learning topic, each simulation
program is written individually to fit that purpose. Although
each program is written individually, all programs may uti-
lize many functions in common. In order to share common
functions with one another, some common-function programs
are written in terms of standard software components. The
software component is Java Beans in the CAI system. In the
instrument module of the CAI system, the simulation programs
are constructed by utilizing these software components to
perform its simulation. In the case of oscilloscope simulation,
the simulation program is composed of some predefined
software components to perform its function. The structure
of an oscilloscope simulation program utilizing the software
componentsisshowninFig.3.Fig.4showstheimplementation
of the simulated oscilloscope. Fig. 5 shows the implementation
of the logic analyzer.
V. EXAMINATION MODULE
Afterstudents finishlearningin theinformationmodule, they
may need some quizzes to check how much they have learned
from the CAI system. The examination program of the exami-
nation module is launched after students complete the informa-
tion module. This program presents some suitable examination
material that students can use to test themselves. After students
complete the examination, they can review their examination
results momentarily. The examination program shows a list of
right and wrong answers to the students. Students can reinforce
their learning after they complete the examination.
In order to present a suitable examination format to students,
the examination program should have adequate examination
questions to cover the module material. Unlike the instrument
module, the examination module contains programs on both the
server and client sides. The examination program on the server
side allows the teacher to provide examination contents in the
form of multiple panels, such as multiple-choice questions,
true/false questions, etc. The server-side program also records
the examination grade that is sent from the client-side of the
examination program. The examination program on the client
side primarily shows the examination contents, which are pro-
vided by the teacher from the server-side to students after they
input their passwords. After students complete the examination,
the program tabulates the grade for this examination and shows
it to the students. The client-side examination program then
sends the examination grade to the server program through
the Internet, and completes the examination session. A block
diagram of the examination module is shown in Fig. 6.
In order to produce multiple forms of examination, an inter-
face that defines the common behavior of the examination con-
tents was created. Any examination content program that meets
with this interface can be used in the examination module. In
thismechanism,multipleforms oftheexaminationcontentscan
be produced for students. Thus a teacher can provide more flex-
ibleexaminationcontentstobetterdeterminetheactuallearning
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90IEEE TRANSACTIONS ON EDUCATION, VOL. 46, NO. 1, FEBRUARY 2003
Fig. 2.Flowchart of the relationship between the information, instrument, examination, and FAQ modules.
Fig. 3.
components.
Class diagram of oscilloscope simulation program using software
progress of the students. A class diagram of the multiple format
examination program is shown in Fig. 7.
Since theserver-side examinationprogram records theexam-
ination grades of the students, the examination module should
Fig. 4.Simulated oscilloscope with two signal sources.
contain a query program to allow students to query their exam-
ination grades. Students can use this query program to query
their grades in past examinations after they complete the exam-
ination. The query program shows students’ past examination
grades in histogram form. Students can review their progress
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HUANG AND LU: JAVA-BASED DISTANCE LEARNING ENVIRONMENT 91
Fig. 5.Simulated logic analyzer.
through this query program. The teacher can review the instruc-
tion progress of this CAI system by querying students’ grades.
Fig. 8 shows the query tool for the CAI system.
VI. FAQ MODULE
When students finish studying the information module, they
may not understand all of the information contained in that
module. Although the instrument module and the examination
module can reinforce students’ learning, students may still
have many questions about the topics in the CAI system. The
objective of the FAQ module is to allow students to post their
questions to the teachers through the Internet. The FAQ module
lists some common frequently asked questions in the WWW
browser. Students can read these FAQs to see if their question
has already been posted and answered.
Similartotheexaminationmodule,thereare serverand client
programs in the FAQ module. Students can post their questions
in the WWW browser, and the client-side FAQ program sends
students’ questions to the server through the Internet. The FAQ
program on the server side allows the teacher to check and an-
swer these questions. The program also receives the questions
sentfromtheclient.Afteransweringthesequestions,theteacher
can post these FAQs in HTML format or mail the answers to the
students.AblockdiagramoftheFAQmoduleisshowninFig.9.
VII. CAI SERVER MANAGEMENT
In order to create a suitable learning environment, the CAI
system is constructed in a client/server architecture. The struc-
ture on the server side is composed of two parts: service pro-
grams and tool programs. The service program consists of three
services in three threads: examination service, query service,
and FAQ service. The tool program helps the teacher generate
instructional material, manage instructional material, and ad-
minister student data and information. These three services are
monitoring in the background when the main server program is
initiated. The tool and administration programs begin whenever
they are opened. When the service program is actuated by the
client, a thread is launched to manage this service. How these
service programs work is shown in Fig. 10.
VIII. CAI SERVICES
The examination service manages examination requests
from students in the client side. When students have completed
studyingthecontentofthetopicintheinformationmodule,they
may use the examination program to test themselves. Students
must first input their passwords. After checking the password,
the service program sends an “ACCESS GRANTED” message
to the client program followed by the examination data. After
students complete the examination, the examination program in
the client side sends the grade to the service program. Finally,
the service program keeps the grade data of the students in the
server.
The query service program handles query requests from
students in the client side. This query service allows students
to know their examination results for past examinations. The
query program reads the recorded data and shows it to students.
After students input their passwords, the query program finds
their examination data and shows students the examination title
and grades. The FAQ service program manages the questions
sent from students on the client side. The FAQ service program
records students’ questions in the server, and allows the teacher
to answer these questions. Unlike the examination and query
services, the FAQ service does not check passwords, and any
one can post questions to the teacher.
The class diagram of the main server and service programs
are shown in Fig. 11.
IX. CAI TOOLS
The CAI tool program is composed of four tool programs:
examination creator program, query program, administration
program, and FAQ program. The examination creator program
helps the teacher create examination materials. The query pro-
gram helps the teacher query all student examination grades.
The administration program helps the teacher administer
student information. The FAQ tool program helps the teacher
check and answer student questions. Since there are many
topics in the information module, some examination materials
are provided at the end of some topics. The objective of the
examination creator program is to help the teacher create
examination contents in the examination module at the end of
topic in the information module. Fig. 12 shows a standard form
of examination content in view-mode, and Fig. 13 shows it in
edit-mode. Fig. 14 shows a special form of examination content
in view-mode, and Fig. 15 shows it in edit-mode.
The administration tool program can help the teacher ad-
minister student information. The teacher can use this tool to
add new student data or delete graduated student data from the
server. With this tool, the teacher can manage student identi-
fication easily. The administration tool program is shown in
Fig. 16. The last tool program is the FAQ tool. The FAQ tool
program shows student questions from the client in a list box.
Aftercheckingandansweringeachstudentquestion,theteacher
canpostthesequestionsandanswersinHTMLformat.Students
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92IEEE TRANSACTIONS ON EDUCATION, VOL. 46, NO. 1, FEBRUARY 2003
Fig. 6.Block diagram of the examination module.
Fig. 7.
be used as the examination content.
Any program that fulfills the examination interface requirements can
Fig. 8.Query tool of the CAI system.
Fig. 9.Block diagram of the FAQ module.
can read these FAQs on WWW browsers through the Internet.
The teacher can mail the answer to the student who has posted
Fig. 10.How the CAI service program handles the services.
Fig.11.Classdiagramofthemainserverprogramandthreeserviceprograms.
this question. With this FAQ tool, students can not only receive
the teaching material from the teacher, but can also send feed-
back to the teacher. Fig. 17 shows the FAQ tool.
X. CONCLUSION
In this paper, a CAI system including four modules (informa-
tion,instrument,examination,andFAQmodules)wasproposed.
Such an environment can help students learn how to use the os-
cilloscope, function generator, or logic analyzer. The informa-
tion module tells students the theory and operation methods of
the instruments and the maintenance data if necessary. The in-
strumentmoduleassiststheinformationmoduleinteachingstu-
dents. In particular, students can practice on the instrument in a
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