Patent Publication Number: US-6993472-B2

Title: Method, apparatus, and program for chaining machine translation engines to control error propagation

Description:
RELATED APPLICATIONS 
     The present application is related to commonly assigned and co-pending U.S. patent application Ser. No. 09/919,257 entitled “METHOD, APPARATUS, AND PROGRAM FOR CHAINING SERVER APPLICATIONS,” filed on even date herewith, and hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to data processing systems and, in particular, to machine translation. Still more particularly, the present invention provides a method, apparatus, and program for chaining machine translation engines to control error propagation. 
     2. Background of the Invention 
     Machine translation (MT) is a computer technology wherein a computer software program or computer hardware translates a textual source human language into some textual target human language. An example is translation from English to German. Machine translation services are provided for many pairs of languages. Typically, a language pair supplier may develop language pair engines that can provide translation for common language pairs. However, to provide a machine translation for every possible combination of source language and target language would require an extremely large amount of time and code. Thus, it is unrealistic to provide a language pair for every possible combination, especially considering that demand for most pairs may be very low or nonexistent. 
     Machine translation may be provided for some pairs by chaining pairs together. For example, translation from German to French may be provided by chaining a German-to-English translation with an English-to-French translation. However, each translation engine may have a degree of inaccuracy or error. By increasing the number of translation engines in a translation, the likelihood of inaccuracy or error is also increased. 
     Therefore, it would be advantageous to provide an improved mechanism for chaining machine translation engines to control error propagation. 
     SUMMARY OF THE INVENTION 
     The present invention provides a mechanism for chaining machine translation engines using linguistic annotation language in the intermediate language. A first machine translation engine is provided that translates the source language text into an intermediate language text marked up with linguistic annotation language. A second machine translation engine translates the intermediate language text into the target language using the linguistic annotation language. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein: 
         FIG. 1  depicts a pictorial representation of a network of data processing systems in which the present invention may be implemented; 
         FIG. 2  is a block diagram of a data processing system that may be implemented as a server in accordance with a preferred embodiment of the present invention; 
         FIG. 3  is a block diagram illustrating a data processing system in which the present invention may be implemented; 
         FIG. 4  depicts an example translation in accordance with a preferred embodiment of the present invention; 
         FIG. 5  is a block diagram illustrating the functional components of a server in accordance with a preferred embodiment of the present invention; 
         FIG. 6  illustrates the functional components of a specific example of a server in accordance with a preferred embodiment of the present invention; and 
         FIG. 7  is a flowchart illustrating the operation of a chain of machine translation engines in accordance with a preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference now to the figures,  FIG. 1  depicts a pictorial representation of a network of data processing systems in which the present invention may be implemented. Network data processing system  100  is a network of computers in which the present invention may be implemented. Network data processing system  100  contains a network  102 , which is the medium used to provide communications links between various devices and computers connected together within network data processing system  100 . Network  102  may include connections, such as wire, wireless communication links, or fiber optic cables. 
     In the depicted example, server  104  is connected to network  102 . In addition, clients  108 ,  110 , and  112  are connected to network  102 . These clients  108 ,  110 , and  112  may be, for example, personal computers or network computers. In the depicted example, server  104  provides data, such as documents, to clients  108 – 112 . In a specific example, server  104  may be a Web server. Clients  108 ,  110 , and  112  are clients to server  104 . Network data processing system  100  may include additional servers, clients, and other devices not shown. In the depicted example, network data processing system  100  is the Internet with network  102  representing a worldwide collection of networks and gateways that use the TCP/IP suite of protocols to communicate with one another. At the heart of the Internet is a backbone of high-speed data communication lines between major nodes or host computers, consisting of thousands of commercial, government, educational and other computer systems that route data and messages. Of course, network data processing system  100  also may be implemented as a number of different types of networks, such as for example, an intranet, a local area network (LAN), or a wide area network (WAN).  FIG. 1  is intended as an example, and not as an architectural limitation for the present invention. 
     To provide service on a scalable range server farm  130  may be used. Server  104  may direct requests from clients to one of the servers in server farm  130  through sprayer  120 . The sprayer distributes requests to one of the servers in the server farm and may perform other functions, such as load balancing. Each server in the server farm may run all the available applications. For example, each server may run a German-to-English translation, an English-to-Spanish translation, and a verification application for verifying whether the requesting client is authorized to access each application. 
     Referring to  FIG. 2 , a block diagram of a data processing system that may be implemented as a server, such as server  104  in  FIG. 1 , is depicted in accordance with a preferred embodiment of the present invention. Data processing system  200  may be a symmetric multiprocessor (SMP) system including a plurality of processors  202  and  204  connected to system bus  206 . Alternatively, a single processor system may be employed. Also connected to system bus  206  is memory controller/cache  208 , which provides an interface to local memory  209 . I/O bus bridge  210  is connected to system bus  206  and provides an interface to I/O bus  212 . Memory controller/cache  208  and I/O bus bridge  210  may be integrated as depicted. 
     Peripheral component interconnect (PCI) bus bridge  214  connected to I/O bus  212  provides an interface to PCI local bus  216 . A number of modems may be connected to PCI local bus  216 . Typical PCI bus implementations will support four PCI expansion slots or add-in connectors. Communications links to clients  108 – 112  in  FIG. 1  may be provided through modem  218  and network adapter  220  connected to PCI local bus  216  through add-in boards. 
     Additional PCI bus bridges  222  and  224  provide interfaces for additional PCI local buses  226  and  228 , from which additional modems or network adapters may be supported. In this manner, data processing system  200  allows connections to multiple network computers. A memory-mapped graphics adapter  230  and hard disk  232  may also be connected to I/O bus  212  as depicted, either directly or indirectly. 
     Those of ordinary skill in the art will appreciate that the hardware depicted in  FIG. 2  may vary. For example, other peripheral devices, such as optical disk drives and the like, also may be used in addition to or in place of the hardware depicted. The depicted example is not meant to imply architectural limitations with respect to the present invention. 
     The data processing system depicted in  FIG. 2  may be, for example, an IBM e-Server pSeries system, a product of International Business Machines Corporation in Armonk, N.Y., running the Advanced Interactive Executive (AIX) operating system or LINUX operating system. 
     With reference now to  FIG. 3 , a block diagram illustrating a data processing system is depicted in which the present invention may be implemented. Data processing system  300  is an example of a client computer. Data processing system  300  employs a peripheral component interconnect (PCI) local bus architecture. Although the depicted example employs a PCI bus, other bus architectures such as Accelerated Graphics Port (AGP) and Industry Standard Architecture (ISA) may be used. Processor  302  and main memory  304  are connected to PCI local bus  306  through PCI bridge  308 . PCI bridge  308  also may include an integrated memory controller and cache memory for processor  302 . Additional connections to PCI local bus  306  may be made through direct component interconnection or through add-in boards. In the depicted example, local area network (LAN) adapter  310 , SCSI host bus adapter  312 , and expansion bus interface  314  are connected to PCI local bus  306  by direct component connection. In contrast, audio adapter  316 , graphics adapter  318 , and audio/video adapter  319  are connected to PCI local bus  306  by add-in boards inserted into expansion slots. Expansion bus interface  314  provides a connection for a keyboard and mouse adapter  320 , modem  322 , and additional memory  324 . Small computer system interface (SCSI) host bus adapter  312  provides a connection for hard disk drive  326 , tape drive  328 , and CD-ROM drive  330 . Typical PCI local bus implementations will support three or four PCI expansion slots or add-in connectors. 
     An operating system runs on processor  302  and is used to coordinate and provide control of various components within data processing system  300  in  FIG. 3 . The operating system may be a commercially available operating system, such as Windows 2000, which is available from Microsoft Corporation. An object oriented programming system such as Java may run in conjunction with the operating system and provide calls to the operating system from Java programs or applications executing on data processing system  300 . “Java” is a trademark of Sun Microsystems, Inc. Instructions for the operating system, the object-oriented operating system, and applications or programs are located on storage devices, such as hard disk drive  326 , and may be loaded into main memory  304  for execution by processor  302 . 
     Those of ordinary skill in the art will appreciate that the hardware in  FIG. 3  may vary depending on the implementation. Other internal hardware or peripheral devices, such as flash ROM (or equivalent nonvolatile memory) or optical disk drives and the like, may be used in addition to or in place of the hardware depicted in  FIG. 3 . Also, the processes of the present invention may be applied to a multiprocessor data processing system. 
     As another example, data processing system  300  may be a stand-alone system configured to be bootable without relying on some type of network communication interface, whether or not data processing system  300  comprises some type of network communication interface. As a further example, data processing system  300  may be a personal digital assistant (PDA) device, which is configured with ROM and/or flash ROM in order to provide non-volatile memory for storing operating system files and/or user-generated data. 
     The depicted example in  FIG. 3  and above-described examples are not meant to imply architectural limitations. For example, data processing system  300  also may be a notebook computer or hand held computer in addition to taking the form of a PDA. Data processing system  300  also may be a kiosk or a Web appliance. 
     With reference now to  FIG. 4 , an example translation is shown in accordance with a preferred embodiment of the present invention. Machine translation engine  410  receives source language text as input and translates the text into a second language, which serves as an intermediate language. The intermediate is not an invented language, such as Esperanto, but an actual natural language or “spoken” language. Machine translation engine  420  receives the intermediate language text as input and translate the text into the target language. 
     Each translation engine may have a degree of inaccuracy or error. By increasing the number of translation engines in a translation, the likelihood of inaccuracy or error is also increased. Furthermore, any error in machine translation engine  410  may be propagated through machine translation engine  420 . Therefore, the quality of translation in the example shown in  FIG. 4  will typically be less than that for a machine translation engine written to directly translate the source language text into a target language. 
     However, the cost of developing a machine translation engine for a particular source language and target language may not be justified by the demand. For example, translation from German (Deutsche) to English and translation from English to Portuguese may be common, while translation from German to Portuguese may be very rare. In this example, the demand for German to Portuguese translation may not justify the cost of developing a specific machine translation engine for that language pair. In fact, even if the demand justifies the demand, machine translation engines may be chained together while a specific machine translation engine for the particular language pair is developed. Thus, the chaining method of  FIG. 4  may be preferred for certain cases. 
     In accordance with a preferred embodiment of the present invention, the machine translation engines may be expanded to use linguistic annotation language (LAL) to control error propagation. LAL is a markup language that is used to mark up source documents that are to be translated. For example, the English clause “he is standing near the bank” may be annotated as “he is standing near the &lt;subject=geology&gt;bank&lt;/subject&gt;.” From the annotation a subsequent machine translation engine will know that the word “bank” refers to a river and not a financial institution. 
     In the example shown in  FIG. 4 , machine translation engine  410  may translate the source language text into the intermediate language and mark up the output with LAL. Again, the intermediate is not an invented language, but an actual natural language that has been annotated to help translate it better. Machine translation engine  420  may then receive the intermediate text as input and use the LAL to more accurately translate the text into the source language. 
     With reference to  FIG. 5 , a block diagram illustrating the functional components of a server is shown in accordance with a preferred embodiment of the present invention. The server includes a controller  502  and applications  504 . The controller controls the execution of applications  504 . Applications  504  may provide services, such as machine translation, that are provided by the server. Applications may be used in conjunction with one another. For example, one application may provide a machine translation service that translates text from a source language to a target language. Another application may provide a statistics service that counts the number of words in the target language text. 
     The server also includes chaining module  510 . The chaining module allows applications to be used together without requiring specific code for passing the output of one application to the input of the next application in the chain. For example, to call a German (Deutsche (de)) to English translation engine (deen) chained with an English to French translation engine (enfr), a client may simply call the chain module to chain deen and enfr. 
     The server may also include properties  512 . Each of applications  504  and the chaining module  510  are registered in the properties file by establishing a name and associating an application to the name. A provider may also register a chain of applications in properties  512  by establishing a name and associating the chain module to that name setting the chain of applications to be chained using a chain option recognized by the chain module. Properties  512  may be embodied as a file stored on the server. 
     The functional components illustrated in  FIG. 5  may be embodied in hardware, software, or a combination of hardware and software. For example, controller  502  may be a processor, such as processors  202 ,  204  in  FIG. 2 , and applications  504  and chaining module  510  may be software executing on the processor. The functional components of the server may also be implemented as firmware. 
     Next,  FIG. 6  illustrates the functional components of a specific example of a server in accordance with a preferred embodiment of the present invention. The server includes a controller  602 , language translation engine LTdeen  604 , and language translation engine LTenfr  606 . LTdeen provides a machine translation service that translates text from German (Deutsche (de)) to English (en). LTenfr provides a machine translation service that translates text from English to French (fr). 
     The server also includes chaining module  610 . The chaining module allows applications to be used together without requiring specific code for passing the output of one application to the input of the next application in the chain. The server also includes properties  612 . LTdeen  604  is registered in the properties file by establishing a name and associating an application to the name. The property keyword “provider” is concatenated with the service insignia to form the name. The text “Provider.deen=address.LTdeen” is used to register the LTdeen application. LTenfr  606  is registered using the text “Provider.enfr=address.LTenfr.” 
     A new service may be registered by establishing a name and associating the chaining module to the name in properties  612 . For example, a German to French translation engine may be registered using the text “Provider.defr=address.LTchain” and setting the chaining options using the text “Provider.defr.options=*chain=deen,enfr.” The defr translation service may also be registered to automatically use LAL by setting an LAL option for each translation application in the chain. for example, as seen in  FIG. 6 , the deen language translation service uses the option “*lal=output” and the enfr language translation service uses the option “*lal=input.” 
     Thus, machine translation applications may be set up to automatically use LAL to control error propagation.  FIG. 6  shows an example in which machine translation services are configured automatically; however, other configurations of language translation engines that mark up the intermediate language text with LAL may be used within the scope of the present invention. 
     With reference now to  FIG. 7 , a flowchart illustrating the operation of a chain of machine translation engines is shown in accordance with a preferred embodiment of the present invention. The process begins and receives text in a source language (step  702 ). A determination is made as to whether a current translation engine is the last machine translation in the chain (step  704 ). If the current machine translation engine is not the last in the chain, the process translates the text into the target language of the engine and marks up the target language text with LAL (step  706 ). Next, the process passes the LAL output to the next machine translation engine in the chain (step  708 ). 
     Then, the process returns to step  704  to determine whether the current translation engine is the last machine translation in the chain. If the current machine translation engine is the last in the chain in step  704 , the process translates the text into the target language without LAL output (step  710 ) and ends. 
     Thus, the present invention solves the disadvantages of the prior art by providing a mechanism for chaining machine translation engines using linguistic annotation language in the intermediate language. A first machine translation engine is provided that translates the source language text into an intermediate language text marked up with linguistic annotation language. A second machine translation engine translates the intermediate language text into the target language using the linguistic annotation language. The use of LAL helps to avoid ambiguities in translation and to control the error propagation between language translation engines. 
     It is important to note that while the present invention has been described in the context of a fully functioning data processing system, those of ordinary skill in the art will appreciate that the processes of the present invention are capable of being distributed in the form of a computer readable medium of instructions and a variety of forms and that the present invention applies equally regardless of the particular type of signal bearing media actually used to carry out the distribution. Examples of computer readable media include recordable-type media such a floppy disc, a hard disk drive, a RAM, CD-ROMs, and transmission-type media such as digital and analog communications links. 
     The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.