JP6148503B2 - Lock control method for mobile communication terminal device - Google Patents

Description

  The present invention relates to a lock control method for a mobile communication terminal device for preventing leakage of information recorded therein when a mobile communication terminal device represented by a smartphone or a tablet computer is lost.

  In recent years, mobile communication terminal devices (hereinafter sometimes simply referred to as “terminal devices”) having communication functions such as smartphones and tablet computers have rapidly spread. These are not only capable of voice calls and data communications by connecting to a mobile phone communication network or public wireless LAN, but also a multi-function tool database that implements various functions by installing and executing various applications. It can be used as

  For this reason, recently, smartphones and the like are not limited to use at the individual level, but are often used for use at the operator level, that is, for execution of business by the operator.

  Here, since mobile communication terminal devices such as smartphones are often taken out and used outdoors, it is fully conceivable that they may be lost or stolen. If the mobile communication terminal is lost, the information recorded on it may be leaked. In particular, when a mobile communication terminal device used for business is lost, very important information such as customer information and facility information may be leaked. It can be a blow. For this reason, operators have a responsibility to prevent information leakage and ensure thorough compliance, and one of the biggest issues is how to protect confidential information in terminal devices in the midst of full-scale smartphone use by businesses. It has become.

  By the way, in order to prevent misuse, abuse and information leakage by third parties who have been picked up in the event of loss or theft of smartphones, etc. A function or a so-called “remote lock” function that disables the use of all functions of the mobile communication terminal device is provided. Therefore, in the case of loss, the subscriber can minimize damage by performing “remote lock” quickly by an operation using another telephone or computer.

  In addition, the mobile communication terminal device itself also requires the input of a personal identification number, fingerprint authentication, face authentication, etc., in order to prevent misuse and abuse of the mobile communication terminal device by a third party who has been found. A “main body lock” function is provided.

  For example, in Patent Document 1 below, there is a method for prohibiting key operation and browsing of internal information by transmitting a command or the like to a mobile communication terminal device lost by a subscriber using another telephone or terminal device. It has been invented.

Japanese Patent Laid-Open No. 2002-218048

However, since the “remote lock” is performed through a communication line, it cannot be performed in an area where the communication line is not connected. In particular, the electric power company that is the applicant of the present application often performs operations such as installation and maintenance of facilities outside the communication area such as a mountainous area, and it is sufficiently assumed that a case where “remote lock” cannot be performed.
On the other hand, even within the calling range, if the SIM card (Subscriber Identity Module Card) is removed by the mobile communication terminal device finder or the like before the “remote lock” operation by the subscriber, “remote lock” becomes impossible. Therefore, there is a problem it is that such can no longer be prevented viewing of internal information.

  In addition, in the “main unit lock” function using a personal identification number, fingerprint authentication, face authentication, etc., it is necessary to enter a personal identification number etc. when using the mobile communication terminal device. Its usability deteriorates.

  On the other hand, if it is necessary to enter a password, etc. only at the initial stage of use such as at the time of start-up, if the mobile communication terminal device is picked up while “main unit lock” is released, The function did not make sense, and there was a problem that information leakage could not be prevented.

  The present invention has been made in view of such circumstances, and mobile communication terminals can be used for mobile communication without using the “main body lock” function based on a personal identification number or the like in a situation where the “remote lock” function of the mobile communication terminal device cannot be used. An object of the present invention is to provide a lock control method for a mobile communication terminal device that can effectively prevent browsing of internal information by a third party who has acquired the terminal device.

In order to solve the above problems, the present invention is a lock control method for a mobile communication terminal device in which business information is recorded,
A step of registering in advance in the mobile communication terminal device a specific use condition that is a condition according to a business purpose of use in which the mobile communication terminal device is used;
And detecting a radio wave state of the mobile communication terminal device receives from the base station,
When the radio wave condition is outside the communication range more than a predetermined time, the steps of the primary locking to disable their use to lock the mobile communication terminal device (primary locking),
Only when the authentication by non-contact communication with a predetermined release key is established, the steps of releasing the primary lock to release the mobile communication locking of the terminal device 1 (primary locking),
Next, when the primary lock of the mobile communication terminal device is released, but the specific use condition is not satisfied, the mobile communication terminal device is locked (secondary lock) to disable its use. The stage of secondary locking,
When a business using the mobile communication terminal device is performed, the mobile communication terminal device in a locked (secondary lock) state is confirmed whether the specific use condition is satisfied, and the specific use condition is satisfied. Unlocking the mobile communication terminal device (secondary lock) only when the mobile communication terminal device is locked, and releasing the secondary lock enabling the use of the mobile communication terminal device .

  Here, the specific use conditions are provided for each equipment / facility / personnel required for the work in which the mobile communication terminal device is used, the date and place where the mobile communication terminal device is used, or in the work in which the mobile communication terminal device is used. The authentication is preferably performed using an electronic tag or a two-dimensional code.

  In addition, it is also preferable that the specific use condition is reconfirmed at a predetermined time interval, and when the specific use condition is not satisfied, the mobile communication terminal device is locked to make the use impossible.

According to the lock control method for a mobile communication terminal apparatus of the present invention, the terminal apparatus is locked when the mobile communication terminal apparatus is out of the communication range (including the state where the SIM card is removed) based on the communication state of the mobile communication terminal apparatus. Thus, it is possible to prevent information recorded in the terminal device from being leaked even in a situation where the “remote lock” operation cannot be performed when the mobile communication terminal device is lost. The authorized user of the mobile communication terminal device carries an electronic tag or the like as a release key for unlocking, for example, and when the terminal device establishes authentication by non-contact communication with the release key, the communication state it is possible to avoid a disadvantage that enable the use and so as to be lever, the use of the terminal apparatus by an authorized user (subscriber) is limited in the communication service area of the terminal device regardless.

In addition, conditions (specific usage conditions) for using the mobile communication terminal device are registered in advance according to the business contents, and when the business is actually performed, the specific usage conditions (for example, the date and time when the business is performed) , lock location, lever be available to the mobile communication terminal device only if it is confirmed that such respective equipment and qualifications are required in business operations) is satisfied, the mobile communication terminal according to the radio wave condition In addition to a lock using a specific use condition (secondary lock) , it can also be locked regardless of the inside or outside of the communication area, so a lost mobile communication terminal Information leakage from the apparatus can be prevented more effectively. Incidentally, the specific operating conditions and the equipment or the like required for operations, to lever so that only the mobile communication terminal apparatus can be used if it is confirmed that the equipment or the like is aligned, for example, safe working It can be a condition of work that equipment such as helmets, safety belts, safety shoes, insulating gloves, etc. necessary for carrying out are available, and it is possible to ensure compliance with safety regulations.

Furthermore, if it is reconfirmed that the specific use condition is satisfied every certain time and the terminal device is locked when the condition is not satisfied, the condition is satisfied once and the lock (primary lock) is released. Even if the mobile communication terminal device is lost or stolen, the risk of information leakage can be minimized by re-locking (secondary lock) .

It is the figure which showed the system configuration | structure for implement | achieving the lock | rock control method of the mobile communication terminal device by a present Example. It is a block diagram which shows the structure of a mobile communication terminal device. It is a flowchart showing the primary lock control by a present Example. It is a flowchart showing the secondary lock control by a present Example.

  The present invention relates to a lock control method for a mobile communication terminal device typified by a smartphone or tablet computer, which has a communication function connectable to a public telephone communication network and can store various information therein. The object of the present invention is to prevent leakage of information recorded in the case where the mobile communication terminal device is lost or stolen. In particular, even when a mobile communication terminal device that has been used for business execution by a business operator and recorded confidential information such as customer information or facility information is lost, information leakage is effectively prevented, Contributes to thorough compliance.

  In this embodiment, the description will be made with the business in the power company, the applicant of the present application, in mind as the business in which the mobile communication terminal device is used, but the business in which the mobile communication terminal device is used is not limited to this. Needless to say.

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram showing a system configuration for realizing a lock control method for a mobile communication terminal device according to the present embodiment. The mobile communication system of the present embodiment includes a mobile communication terminal device 1, a server computer 2, a base station 3, a base station control device 4, an exchange 5, a home location register 6, an IC tag 7, and a GPS satellite. 8.

  As long as the mobile communication terminal device 1 can communicate using the mobile phone communication network 11 while moving and can record information in the mobile communication terminal device 1, a smartphone, a tablet computer, a mobile phone, a notebook, PCs, PDAs, digital cameras, etc. are included.

  The server computer 2 is used by a business operator who is a subscriber of the mobile communication terminal device 1 to perform lock control of the mobile communication terminal device 1 and can be wirelessly connected to the mobile communication terminal device 1 through the Internet line 12. ing. The business operator connects the mobile communication terminal device 1 with a condition for using the terminal device, that is, a specific use condition that is a condition for releasing the lock, by connecting to the mobile communication terminal device 1 using the administrator authority. Set and memorize.

  The base station 3 is a facility installed by a communication company in various places to establish a telephone communication network over a wide area, and includes a base station antenna 13 for performing wireless communication with the mobile communication terminal device 1. The base station control device 4 is a device for controlling and managing a large number of base stations 3, and is connected to the exchange 5 by wire.

  The home location register 6 is a database that checks in which area the mobile communication terminal device 1 is located and manages its location information. When the terminal device is turned on or when the area changes due to movement, the location information is registered in the home location register 6 by communication with the terminal device, and the communication company determines each mobile communication terminal device based on the location information. Know where you are and perform communications such as telephone calls.

  The IC tag 7 is a kind of RFID (Radio Frequency IDentification), and information is exchanged by radio communication using an electromagnetic field or radio wave from a tag in which identification information is embedded. The IC tag 7 used here has a communication distance of about several meters with the IC tag reader of the mobile communication terminal device 1. Information for identifying the solid to which the IC tag 7 is attached is recorded. In the present invention, the IC tag 7 is mounted on an employee ID card carried by an employee of a business operator who is a user. To be used as a release key (identification information) for use, helmets, safety belts, safety shoes, insulated gloves, etc. It may be used to check whether or not

  The GPS satellite 8 is an artificial satellite used in a global positioning system, and the mobile communication terminal device 1 can measure the current position by receiving radio waves from the GPS satellite 8.

FIG. 2 is a block diagram showing the configuration of the mobile communication terminal device 1.
In FIG. 2, the mobile communication terminal device 1 includes an antenna 21, a radio communication circuit unit 22, a signal processing unit 23, a control circuit unit 24, a storage circuit unit 25, a position detection unit 26, a clock unit 27, The lock unit 28, the handset 29, the display unit 30, the key operation unit 31, and the IC tag reader 32 are configured.

The control circuit unit 24 executes various processes based on the program.
The memory circuit unit 25 is a program executed by the control circuit unit 24, identification information of the user (subscriber) of the mobile communication terminal device 1 and various personal information (for example, telephone directory data, mail address, etc.), as well as a business operator Stores confidential information such as customer information, facility information, and the like, and stores a release key for using the mobile communication terminal device 1 and information for collating specific usage conditions described later.

The position detecting means 26 receives radio waves from the base station 3 and detects the current position based on these. Then, the position information is registered in the home location register 6, and the position information is updated at a constant cycle. Further, the position detecting means 26 can detect an accurate current position by receiving radio waves from the GPS satellite 8.
The detection of the current position by the position detection means 26 is normally performed by receiving radio waves from the base station 3, but when the radio waves from the base station 3 cannot be received, the radio waves from the GPS satellite 8 are detected. It is done by receiving. In that case, the position information cannot be registered in the home location register 6, and the position information is updated and registered in the home location register 6 again when moving to the communication area again.

  The lock unit 28 stores information when a remote lock operation is performed according to a radio command sent from the base station 3, when the radio wave state is out of the communication range for a certain time or when a specific use condition described later is not satisfied. The reading and writing of various kinds of information in the circuit unit 25 is locked, and it is locked so as not to accept any input by an external operation, except for a response operation for incoming calls. Further, when a predetermined condition is satisfied, the lock unit releases the lock of the mobile communication terminal device 1 once locked, and enables the use.

  The IC tag reader 32 is a device that reads information recorded on the IC tag 7 by performing non-contact communication with an external IC tag 7 (passive tag).

  In the mobile communication terminal device 1, the operations of the antenna 21, the wireless communication circuit unit 22, the signal processing unit 23, the clock unit 2717, the handset 29, the display unit 30, and the key operation unit 31 are well known, and the description thereof will be given. Omitted.

  Next, a lock control method for a mobile communication terminal device according to the present invention will be described. Hereinafter, when there is a mobile communication terminal device outside the communication range and remote lock is impossible by communication, the lock control method of the mobile communication terminal device for preventing information leakage is [primary lock control], regardless of the communication range outside the communication range. First, the lock control method of the mobile communication terminal device for complying with specific usage conditions, which are necessary conditions for preventing information leakage and performing business, will be described as [secondary lock control]. It is assumed that business information is recorded in the mobile communication terminal device 1 and that it is necessary to use the mobile communication terminal device 1 to start the business.

[Primary lock control]
FIG. 3 is a flowchart showing the primary lock control method.
The present invention relates to a lock control method for a mobile communication terminal apparatus in which business information is recorded, wherein the mobile communication terminal apparatus 1 detects a radio wave state received from a base station 3, and the radio wave state is longer than a predetermined time. The mobile communication terminal device 1 is locked only when the mobile communication terminal device 1 is locked and cannot be used when it is outside the communication range, and when authentication by non-contact communication with a predetermined release key is established. Releasing.

―Start-up stage―
This stage is a stage in which the user is first confirmed when the mobile communication terminal device 1 is powered on.
First, the mobile communication terminal apparatus 1 acquires position information by establishing communication with the base station 3 and registers the position information in the home location register 6. In addition, the mobile communication terminal device 1 normally asks the user to input a password when the power is turned on, thereby confirming whether the user has a legitimate authority, and authenticating with a password. Only the terminal device can be used. In addition, when the place at the time of power-on is out of the communication range, in addition to inputting the password, the following release key is also verified.

―Radio signal detection stage―
This stage is a stage in which whether or not the mobile communication terminal device 1 is in the communication area is confirmed at regular intervals.
The mobile communication terminal apparatus 1 detects the current position by receiving radio waves from the base station 3, and updates and registers the position information in the home location register 6 at regular intervals such as every 15 seconds.

― (Primary) lock phase―
This stage is a stage in which the input operation is locked when the mobile communication terminal device 1 is outside the communication range.
The mobile communication terminal apparatus 1 receives radio waves from the base station 3 at regular intervals, and if the reception state is out of the communication range where position information cannot be acquired for a certain period of time or more, for example, 30 seconds or more, the current position is the base station 3. The lock unit 28 locks the operation in order to prohibit the use of the mobile communication terminal device 1.
Even when the SIM card is removed, communication with the base station 3 becomes impossible, and the lock unit 28 locks the operation in the same manner as when the SIM card is out of the communication range.

― (Primary) unlocking stage―
This stage is a stage in which the mobile communication terminal device 1 locked outside the communication area can be used by releasing the lock using the release key.
When it is determined that the user has moved out of the communication range due to movement (or is determined to be out of communication range since the power was turned on), or when the SIM card is removed, the mobile communication terminal device 1 is an employee. Attempts to communicate with the IC tag 7 as a release key (identification information) attached to the certificate. When the communication with the IC tag 7 is established and the collation (authentication) between the release key and the information recorded in the mobile communication terminal device 1 is completed, it is determined that the user is an authorized user and the lock is released. The mobile communication terminal device 1 can be used. On the other hand, when collation cannot be completed, it is determined that the user is not an authorized user, the locked state is maintained, and use of the mobile communication terminal device 1 remains prohibited. The communication range of the IC tag is up to about several meters.

  As described above, according to the [primary lock control] method of the present embodiment, even when the mobile communication terminal device 1 is lost or the like and is out of the communication range, the “remote lock” operation cannot be performed. It is possible to prevent the information recorded in the information from leaking. In addition, by enabling the use of terminal devices by non-contact authentication using a release key carried by authorized users outside the communication range, the inconvenience of restricting the use of authorized user terminal devices outside the communication range can be avoided. In addition, it is not necessary to input a password or the like every time the terminal device is used.

  The present invention is not limited to the case where a business operator who is a communication contract subscriber uses the mobile communication terminal device 1 as a tool for performing business, but the individual who is a communication contract subscriber uses the mobile communication terminal device for personal use. The present invention can also be applied when 1 is used.

[Secondary lock control]
This invention is a lock control method for a mobile communication terminal device in which business information is recorded,
A step of registering in advance in the mobile communication terminal device 1 a specific use condition that is a condition according to the purpose of use for business in which the mobile communication terminal device 1 is used, and a radio wave state received by the mobile communication terminal device 1 from the base station 3 A step of detecting, a step of locking (primary) the mobile communication terminal device 1 when the radio wave condition is outside the communication range for a certain time or more, and disabling the use, and authentication by non-contact communication with a predetermined release key Only when the mobile communication terminal device 1 is established, the mobile communication terminal device 1 is unlocked (secondary) in advance when the mobile communication terminal device 1 is unlocked (primary) and when the mobile communication terminal device 1 is used. The device 1 confirms whether or not the specific use condition is satisfied, and only when the specific use condition is satisfied, unlocks (secondary) the mobile communication terminal device 1 and enables its use. Including.

  In this [secondary lock control], in addition to the primary lock control of the mobile communication terminal device 1 based on the communication state with the base station 3 in the above [primary lock control], the specific use condition is satisfied. The secondary lock is controlled so that the lock is released only when the condition is satisfied. Note that the “start-up stage”, “radio wave state detection stage”, “(primary) lock stage”, and “(primary) lock release stage” described above are not particularly changed and will not be described.

―Specific usage conditions registration stage―
This stage is a stage in which conditions (specific use conditions) for enabling the use of the mobile communication terminal device 1 are set in accordance with a business schedule performed by the administrator using the mobile communication terminal device 1.
First, prior to performing a task using the mobile communication terminal device 1, an administrator such as a supervisor who directly belongs to the user of the mobile communication terminal device 1 connects to the mobile communication terminal device 1 from the server computer 2 using administrator authority. Then (or by direct input to the mobile communication terminal device 1 to be used), the specific use condition is written and stored in the storage circuit unit 25.
Here, the specific use conditions are the date and place where the work performed using the mobile communication terminal device 1 is performed, and the items required for the work, such as helmets, safety belts, safety shoes, insulating gloves, etc. Equipment, machinery and equipment that are essential for work, the number of personnel and qualifications that are necessary for business execution. In order to judge the suitability of these specific use conditions, each item is affixed with an IC tag 7 on which identification information for identifying each item is recorded, and the employee ID card carried by the employee also has its tag. An IC tag 7 on which information for identifying an employee and determining the qualification possessed by the employee is recorded.

―Specific usage condition confirmation stage―
This stage is a stage in which the mobile communication terminal device 1 in a locked state confirms the suitability of the specific use conditions at the site where the business is performed.
First, the mobile communication terminal device 1 detects the time from both the clock unit 27 and the radio wave from the GPS satellite 8. At this time, when the time can be detected from both, the time detected by the radio wave of the GPS satellite 8 is prioritized. Then, it is confirmed whether or not the current time is within the date and time that is a schedule for performing the work, which is a specific use condition registered and stored in the mobile communication terminal device 1 in advance.
Next, the mobile communication terminal device 1 tries to detect the current position by receiving the radio wave from the base station 3, and also tries to detect the current position by receiving the radio wave from the GPS satellite 8. Here, it is sufficient that the current position can be detected with an accuracy of a radius of several tens of meters. The current position may be detected by either radio waves from the base station 3 or radio waves from the GPS satellite 8. Then, it is confirmed whether or not there is a current position in a place (in the area) in the schedule for performing the business, which is a specific use condition registered and stored in the mobile communication terminal device 1 in advance.
Furthermore, the mobile communication terminal device 1 performs wireless communication with the IC tag 7 around (several m to about 10 m) by the IC tag reader 32, so that the specific use condition registered and stored in the mobile communication terminal device 1 in advance is stored. Confirm that all the items essential for the work, the number of personnel and qualifications required for the work are all available.

― (Secondary) unlocking stage―
This stage is a stage in which when it can be determined that all the specific use conditions are satisfied, the (secondary) lock of the mobile communication terminal device 1 is released and the use is enabled.
When the mobile communication terminal apparatus 1 in the locked state determines that the specific use condition stored in advance is satisfied, the user can use the mobile communication terminal apparatus 1 by releasing the (secondary) lock. Is possible. As a result, the user can start the scheduled work.
Note that this lock release is limited to the execution of specific functions related to the scheduled work and data reference, and other functions and data are kept locked so that they cannot be executed or referenced. May be.
On the other hand, if any part of the specific use conditions is not satisfied, the mobile communication terminal device 1 does not release the lock, and notifies the user to that effect (which specific use conditions are inadequate). . The (secondary) lock is released only when all of the specific use conditions are satisfied.
By the way, if this unlocking is attempted at the time of departure from the work site, it is possible to check whether the goods and personnel necessary for the work are available. In other words, at the time of departure, the specific use conditions other than the date and place where work is performed must be satisfied in principle, so it is possible to check for missing goods and personnel by trying to unlock. .

―Relock phase―
This stage is a stage in which once the (secondary) lock is released, the mobile communication terminal device 1 is (secondary) locked again if the specific use condition is not satisfied.
Even when it is confirmed that all the specific usage conditions stored in advance at the time of the (secondary) unlocking stage are satisfied, the mobile communication terminal device 1 can be set at a constant time interval (for example, every 3 minutes). ) To reconfirm the specific usage conditions. If even a part of the specific use condition is not satisfied, the (secondary) lock is performed again so as not to accept the input by the external operation. After the lock is performed again, the lock is not released until it is confirmed that the predetermined specific use condition is satisfied again by returning to the specific use condition confirmation stage.

  As described above, according to the [secondary lock control] method of the present embodiment, the conditions (specific use conditions) for using the mobile communication terminal device 1 are set according to the business schedule, and the confirmation can be made locally. By enabling the use of the mobile communication terminal device 1 only, for example, even when the mobile communication terminal device 1 is stolen, the risk of information leakage can be almost eliminated, and at the same time, it is necessary for business execution. It is possible to confirm that the conditions are met and to contribute to thorough compliance.

The specific usage conditions are confirmed by wireless communication using the IC tag 7 and the IC tag reader 32. In addition, QR codes (registered trademark) described on articles and employee ID cards are also used. two-dimensional code is read by using the two-dimensional code reader may be Rukoto to perform the method of transmitting the information to the mobile communication terminal device 1.

DESCRIPTION OF SYMBOLS 1 Mobile communication terminal device 2 Server computer 3 Base station 4 Base station control device 5 Switching center 6 Home location register 7 IC tag 8 GPS satellite 11 Mobile telephone communication network 12 Internet line 13 Base station antenna 21 Antenna 22 Wireless communication circuit unit 23 Signal Processing unit 24 Control circuit unit 25 Storage circuit unit 26 Position detection means 27 Clock unit 28 Lock unit 29 Handset 30 Display unit 31 Key operation unit 32 IC tag reader

Claims (5)

A lock control method for a mobile communication terminal device in which business information is recorded,
A step of registering in advance in the mobile communication terminal device a specific use condition that is a condition according to a business purpose of use in which the mobile communication terminal device is used;
And detecting a radio wave state of the mobile communication terminal device receives from the base station,
When the radio wave condition is outside the communication range more than a predetermined time, the steps of the primary locking to disable their use to lock the mobile communication terminal device (primary locking),
Only when the authentication by non-contact communication with a predetermined release key is established, the steps of releasing the primary lock to release the mobile communication locking of the terminal device 1 (primary locking),
Next, when the primary lock of the mobile communication terminal device is released, but the specific use condition is not satisfied, the mobile communication terminal device is locked (secondary lock) to disable its use. The stage of secondary locking,
When a business using the mobile communication terminal device is performed, the mobile communication terminal device in a locked (secondary lock) state is confirmed whether the specific use condition is satisfied, and the specific use condition is satisfied. The mobile communication terminal device is unlocked only when the mobile communication terminal device is locked (secondary lock), and the secondary lock enabling the use of the mobile communication terminal device is released . Lock control method. 2. The lock control method for a mobile communication terminal device according to claim 1 , wherein the specific use condition is a date and time when a business using the mobile communication terminal device is performed. 2. The lock control method for a mobile communication terminal device according to claim 1 , wherein the specific use condition is a place where a business using the mobile communication terminal device is performed. The specific conditions of use, according to claim 1, the mobile communication terminal device is the equipment required for the work to be used, the authentication by the electronic tag or two-dimensional code provided at the facility or personnel, characterized in that Lock control method for a mobile communication terminal apparatus. The specific use condition is reconfirmed at predetermined time intervals, and when the specific use condition is not satisfied, the mobile communication terminal device is locked and the use is impossible. The lock control method of the mobile communication terminal device according to 1 .