E-readers and other electronic devices may now store entire books in computer memory, but some readers still prefer books in hardcover formperhaps even borrowed from libraries. To assist them with such transactions, a wireless system has been developed that can check in and check out books at a counter, with receipts sent to a patron's e-mail address. The system is fully automated and environmentally friendly, with no paper receipts. It has some minimum power requirements for detecting books at check-in and check-out operations, with typical processing times of 19.5 and 18.4 s, respectively. The system is implemented in hardware using a CSL CS771 reader, personal computer (PC), and two CSL antennas. It is written in C# programming language with structured-query-language (SQL) database. In any library, two of the key functions are book check in and book check out.1 Most of the check-out and check-in systems currently used in libraries require a great deal of effort on the part of the user.2 These systems are time consuming and inefficient. In addition, most of the current systems still use paper receipts to verify completion of a check-in or check-out transaction. By replacing these with an electronic receipt via e-mail, cost can be reduced, and the system made more efficient and environmentally friendly.3-5
The wireless library system employs a timer to control all transactions and minimize user involvement. When an item must be checked out, a user puts his or her radio-frequency-identification (RFID) identity card and the items to be checked out on a counter. An RFID reader at the counter will detect the RFID card and the RFID tags attached to the books, and the data for each will be retrieved from the system's database. The system displays information by means of a graphical user interface (GUI) designed to let the user know what the system has recorded. To check in books, a user need only drop them into a slot in the counter. The RFID tags for each book will be detected and the information will be retrieved for the remainder of the transaction. The GUI will also update the user in this case. At the end of the transaction, an electronic receipt will be sent to a user's e-mail address.
The mechanical part of the system (the counter) was designed and drawn using AUTOCAD design software. The computer-aided-design (CAD) software and the system's GUI were created using C Sharp programming language. In the following sections, the electrical, mechanical, and software design will be presented, along with the final results.
The software component of the hands-free check-out and check-in system has one main program (the check-out and check-in program) and one subprogram (the registration system for items and users). The hands-free check-out and check-in system was divided into three subsystems: the main, check-out, and check-in systems.
The main system is used to determine whether a user is going to check out or check in the items. When there is a RFID tag detected by the RFID antenna, the RFID tag's ID will be retrieved and sent to a PC's SQL database for temporary storage through the RFID reader. The main system will then determine what needs to be done next based on the data in the database. If one RFID card represents the user and one or more RFID tags represent the items detected, the main system will proceed to the check-out transaction. If any RFID tags that represent items that are currently checked out are detected by antenna 2, the main system will proceed to the check-in transaction. If both conditions stated above occur at the same time, the main system will proceed to the check-in transaction first. Figure 1 shows the main program flow chart.
For the check-out system, once the IDs of the RFID card and the RFID tags have been retrieved, the identity of the user is determined by referring to the database. The system also determines the quantity of books that have been checked out by the user and whether the user has any unpaid penalty. If the user has an unpaid penalty or has checked out the maximum number of books allowed, that user will not be allowed to check out any items. The system will always make sure that the number of books to be checked out by the user does not exceed the maximum number. After confirming that all of these conditions are fulfilled, the system will process the items. If there are any items that cannot be checked out, the system will inform the user by stating the reason (borrowed or for reference only). The items that have been processed through the check-out transaction will be updated in the item database. At the end of the transaction, the system will send a receipt to the user's e-mail account. The GUI of the system is designed to inform the user what the system is doing at all times. Figure 2 shows a flow chart for the check-out system.
For the check-in system, once the IDs of the RFID tags have been retrieved, the status of each book is determined. In the check-in system, a user can return many books at the same time. Every time the system detects a book that has been dropped into the slot, the system will wait for five seconds until no more books are dropped in. After the waiting period, the check-in system will process the books to be checked in. When the system is processing the books, the GUI will display the books that have been processed. The system will determine whether the book that has been processed was returned on time. If a book is returned late, the penalty will be calculated according to the rate set by the librarian through the system settings. The penalty charged will then be recorded in the user database. A receipt will be sent to the user's email account at the end of the transaction. Figure 3 shows the check-in system flow chart.
The registration system can be divided into two parts: item and user registration. Item registration is used to register all of the items in the library in a database. All of the information regarding the items will be saved into the item database. The system is designed to simplify the management work of the librarian. This registration system is also equipped with the ability to update, edit, search, and delete the data inside the item database.
User registration is used to register new users into the database, with user information stored in the database through this system. There are many types of important user information that must be provided to the libraryincluding the e-mail address of the user, which is used for sending receipts. In addition, this system was equipped with the ability to update, edit, search, and delete the data in the user database.
Figure 4 (a) shows the main page for the hands-free check-out/check-in system. The logo Senstech refers to functionality that is used to load into the settings part of the system. The system settings can be divided into two categories: librarian settings and RFID settings. In the librarian settings, several sections are important to be set. The quantity of books can be adjusted to set the maximum number of books that can be borrowed by a library patron. The e-mail address, password for the e-mail address, SMTP host, and SMTP address are used to send an e-mail receipt to a patron. The penalty in the setting part shows the rates of penalty charged to the patron for late return of a book. For the RFID settings, all important adjustable antenna settings and reader settings are included. The form's animation shows instructions for using the system. At the bottom of the form, there is an "EXIT" button, which is used to close the hands-free check-in/check-out program.
After the RFID antenna detects a patron's library card and book, the system screen will appear like Fig. 4(b). The system will display the quantity of books that can be checked out and the quantity of books checked out to that point . If a book cannot be checked out, it will be displayed in the "Book cannot be checked out" section. The reason why the book cannot be checked out also will be shown. When a book to be checked in is dropped into the check-in slot, the screen of Fig. 4(c) will appear. Following the transactions, an e-mail e-receipt will be sent to the patron. If a patron is late in returning a book, the book will be highlighted and, subsequently, an e-receipt with penalty will be generated and sent to the patron.
Figure 4(d) shows the log-in menu for the registration portion of the software. Each librarian will have a different ID and password to log into the system. When the system identifies an authorized user, it will set up the RFID reader and switch to the menu part of the software. On the menu page Fig. 4(e)>, the librarian can choose either to manage a customer's database or a book's database. This menu is divided into those two sections (customer and book). Figure 4(f) shows where a new student can be registered. By scanning a student's library card, the student's library card ID will be shown in the system's text box. The system will then prompt a librarian for important information for the transaction, including matriculation number, name, and e-mail address.
As the table shows, the books' RFID tags can be effective read in either vertical Fig. 5(a)> or horizontal Fig. 5(b)> positions. But it has been found that the RFID system is less effective when the books are not arranged in an orderly fashion on top of the system hardware Fig. 5(c)>. When the books are arranged in order, about 10 books can be detected (a thickness of about 15 cm). When the RFID tags overlap, performance can be affected. The average number of books can be detected at about 8 to 10 books at an average thickness of 21 cm. For books with an average thickness of 26.56 cm, the average quantity that can be detected is about 12 books.
As the table shows, reference books with difference sizes lead to enhanced RFID performance compared to books with equal size, or as many as 13 to 16 books of different sizes can be detected with the RFID system. Since a book for a thesis tends to be thin (about 1.5 cm thickness), the distance between RFID tags is shorter, leading to overlapping tags and interference for the RFID reader. Hence, the maximum quantity of thesis books that can be detected is five books and the maximum quantity of reference books that can be detected is 10 books.
When books are being dropped back into the system (checked in), they may fall into many positions. Figure 6 shows a book position for which the RFID tag inside the book cannot be detected by the RFID reader. The difficulty in reading the tags is because the RFID tags inside the books are perpendicular to the RFID reader's antenna. Not enough power can be generated to transfer information from the tags to the reader in this situation. From tests conducted on the system, it was found that the RFID reader's antenna must have minimum transmit power of about +20.5 dBm for book check-out for antenna 1 and about +16.1 dBm minimum transmit power for check-in with antenna 2. This analysis was performed with a thesis book, which was placed in vertical and horizontal positions (Fig. 7, Fig. 8 and Fig. 9).
After completing the interface between the control software and the RFID hardware for this system, an analysis was performed to get an idea for the time required for different transactions. It was found that checking out a book consumed about 18.42 s on average while checking in a book consumed about 19.5 s on average.
In conclusion, RFID technology can be effectively applied to a library book check-in/check-out system. The system can be automated and is efficient and environmentally friendly, as it sends notices by means of e-mail rather than printed paper forms. Based on the initial results of this system, it is believed that it could be quite useful when implemented on a large scale. For check-out, it can detect five books at the same timeat relatively low power levelswhile requiring less than 20 s time for either check-in or check-out operations.
JEENG JI LEE, Student
MIK KIAN HING, Student
YIN FEN NG, Student
J.S. MANDEEP, Researcher
M.T. ISLAM, Researcher
A.A.A. BAKAR, Researcher
N. ZAINAL, Researcher
N.H. TALIB, Student
Department of Electrical
Electronic & System Engineering
Faculty of Engineering & Build Environment
Universiti Kebangsaan Malaysia
Selangor Darul Ehsan
e-mail: firstname.lastname@example.org (Lee)
The authors would like to thank Universiti Kebangsaan Malaysia and SENSTECH (PKT 1/2010) for supporting this work.