Lecture Notes in Computer Science- P46 pot

Figure 13 shows a flash quiz in which the student practices how to use an array of a two dimensional sort variable of character type.. Students can understand the fact that the charac-te

Fig 11 If-else quiz made with flash

Fig 12 If-else quiz operation

figure 11 If the student inputs a value into the text-box which is a multiple of three it draws a red box If not, it draws a yellow box, as shown in figure 12 If the student wants to repeat from the beginning, he or she only needs to press the button for the first stage

Figure 13 shows a flash quiz in which the student practices how to use an array of

a two dimensional sort variable of character type If the student inputs a free character line in the text-box indicated by the finger, a character is stored in a picture of the memory , below an address value Students can understand the fact that the charac-ters are stored in a[0], a[1], a[2], a[3], in sort element variables of character form In this case it's expressed in pointer form, it can be shown as *a, *(a+1), *(a+2), *(a+3)

Fig 13 Quiz about a sort variable of the character type

Fig 14 Quiz operation about a sort variable of the character type

Figure 14 shows that this quiz is in progress, and the student has input C++, JAVA, XML, FORTRAN into the text-box and then presses the result checking button The student can verify that each character in the lines were placed into each element a[0], a[1], a[2], a[3] in a sort variable of the character form

2.2 Flash Animation Production to Understand Concepts

Assume that an integer number's data occupies two bytes of memory , and consider positive numbers and negative numbers The range of numbers which is possible is -32768-32767 If there is a smaller value than -32768 among the values assigned to variable, an overflow occurs An underflow is assigned to smaller numbers than can

be assigned to a variable An overflow is assigned to larger numbers than can be as-signed to a variable In order to make overflow and underflow concepts easier for students to understand,, we produced a scenario and implemented flash as follows A fish is compared to an integer number's data and a nursery is compared to the role of

Fig 15 An integer number’s range

Fig 16 Example of an underflow

Fig 17 Example of an overflow

data contained in variables The proper fishes only live within a fish tank, but the smaller fishes will escape from a net, as shown in figure 6 This is an underflow Very large fishes will escape by tearing a net, as shown in figure 7 Therefore, figure 7 shows that large fishes can’t be put in a net

2.3 Production of a JAVA Applet for the Purpose of Understanding Algorithms

There are educational contents which consist of a sort algorithm and hanoi-top transfer algorithms, which deal with the C language and are comparatively complex algorithms[10-11] We use JAVA to utilize an algorithm learning applet on the web Real-time technical animation with JAVA threads is used to aid in understanding an algorithm[12-15]

Firstly, figure 18 is the main screen of a sort algorithm learning applet In this study, we deal with five sort algorithms, namely, bubble sort, selection sort, insertion sort, shell sort, and quick sort

The entire applet consists of the top toolbar, the source code implementing each sort algorithm as C language, at the left side, and the animation pad, at the right side This pad is arranged randomly to sort values Based on a student's inputted sort factor,

we used it to see how to randomly arrange the numbers from one to the number of the sort factor For example, when a student performs a ten sort, the applet shows on the first screen that numerals from 1 to 10 are randomly arranged

Fig 18 Applet of sort learning algorithms

Fig 19 A numeral pad animation process

animation shows an image, as shown in figure 19 The sort animation process shown

in the figure first changes the numeral pad into a heavy yellow(a), continuously moves vertically in space(b), exchanges a pad in (c), finally moves vertically, then the color of a pad changes into the original color(d)

The animation process, such as that of figure 20, shows how numerals are sorted

By contrast, the characteristics of sort algorithms can be analyzed through graph an-imations, such as figure 20 When the student presses the ‘graphic analysis’ button to see this sort process as a graph, a new frame window is created and the sort process is shown as an animated graph Figures 20 shows examples., These are screens which display a bubble sort process

Fig 20 Sort process graphs

The axis X is j and the axis Y is the value a[j] (a) is the first stage, prior to sorting, (b) the halfway stage and (c) the final stage We can see from the graph that the upper portion sorts quickly and the lower portion is sorting gradually Thus, the time re-quired for a bubble sort is very long because of the need to search for the maximum value and sort it imprecisely

When the sorting is finished, two components of information appear in the bottom

of the applet, as shown in figure 21 Students check how often values are compared in order to sort information, and how often values are exchanged Then, this can be saved based on their sorts

Data saved will be used later, with a measure comparing advantages and disadvan-tage of the sorts For example, profitable algorithms are selected based on the number

Fig 21 Comparison of sorts and information window of the exchange times