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Towards CIM Based Control CentersGelli Ravikumar, Student Member, IEEE, S. A. Khaparde, Senior Member, IEEE, Rushikesh K. Joshi

Abstract—New generation of future power system controlcenters need a paradigm shift in their utility IT operations,coordinated use of applications and the architectural designsto meet new challenges. However, literature on comprehensivearchitectural design and implementation towards this direction isscarce. In this paper, an architecture design and implementationaspects are demonstrated for integrating applications and formigrating legacy control centers towards future generation smartgrid. Appropriate adoption of open standards such as thecommon information model (CIM) is endorsed. Though the CIMstandard is matured at model level, many utilities are facingdifficulties in managing data exchanges. As a consequence of thelack of integration capabilities, difficulties are faced in deliveringprompt and accurate decisions in response to grid disturbances.Standards-based integration of systems and applications has be-come imperative. This paper presents an approach for integratinginter-utility and intra-utility application systems through CIMframework. The architecture comprises components for dataintegration & access, CIM based plug-in adapters and third-partyapplication integration. The details of this architecture along withthe intricate relationships between various layers and the opensource technologies are described. The proposed architectureincludes components such as CIM XML creators, CIM XMLdatabase adapters, CIM XML application adapters for powersystem applications. The applications over this architecture workas web applications. A case study involving WR 400 kV networkis illustrated to demonstrate migration strategy. Another casestudy involving load flow and topology processing applications isillustrated to elaborate the proposed architecture on data froma 400 kV 20-substation state network.

Index Terms—CIM, Client-Server model, Control Center,Legacy Migration, Power System Applications, Smart GridArchitecture, SVG.

I. INTRODUCTION

Utility application integration and coordination under the

smart power grid environment can be facilitated more effec-

tively only with standards based implementation of control

center application systems. In order to meet the ever growing

demand for energy and to achieve a competitive electricity

market, the present power utility business all over the world

is moving towards restructuring of the power industry and

towards interconnection of power networks at all levels. But

the existing utility infrastructure encompasses heterogeneous

components in both software and hardware systems. These

components are built on incongruent information models and

communication protocols, thus creating hurdles for integration.

It has been observed that the number and the complexity

of the utility business functions performed by the power

control centers are significantly higher in this power industry

Gelli ravikumar (gravikumar@iitb.ac.in) and S. A. Khaparde(sak@ee.iitb.ac.in) are with the Department of Electrical Engineering,and Rushikesh K. Joshi (rkj@cse.iitb.ac.in) is with the Department ofComputer Science and Engineering, at Indian Institute of TechnologyBombay, Powai, Mumbai, India.

environment which is enabled by a change towards the smart

power grid architecture [1].

To enable inter-operable environment at intra-utility and

inter-utility control center application systems in the new

smart power grid environment, the development of common

information model (CIM) standard is a core research in this

field. In this paper a brief overview of CIM is presented

and the rationale for the inevitability of the approach in

modern power systems is discussed. In spite of availability

of adequate literature and standards documents on CIM, the

adoption of CIM in coordination with proprietary applications

for integration is still cumbersome at utility level due to a lack

of information on how to implement and manage CIM based

applications. In this context, the focus of this paper has been

to present a framework for integrating utility control center

applications through CIM, and to demonstrate the solution

architecture with case studies. The framework is aimed at

facilitating seamless integration of applications so that system

operators can coordinate with multiple application systems for

performing a grid functionality.

The rest of the paper is organized as follows: Section II

presents the overview of common information model. Section

III explains the high level strategy for migration of control

centers towards adopting CIM. Section IV elaborates the

utility application integration architecture based on the CIM

framework. Finally, two illustrative case studies are presented

in Section V.

II. A BRIEF OVERVIEW OF CIM

The field of power system industry has come across prob-

lems associated with information interoperability at conven-

tional control centers since electrical utilities relied on in-

house or proprietary systems and non-ISO standard protocols

to achieve information exchange. Therefore, the power system

architecture discipline is motivated by the need to address

information interoperability with the standard information

model such as Common Information Model (CIM) [2], which

has been designed to model the power system domain and its

applications. The goal, however, is to make minimum effort

and get maximum benefit in terms of non functional quality

attributes such as flexibility, accessibility and re-usability over

power grid applications.

The CIM standard is a power systems domain model which

has been evolving for more than two decades of collaborative

efforts by experts from multiple domains world wide [3]. CIM

has evolved into an overarching domain model that represents

the entire value chain of power sector covering wide range

of concepts. The inception, need, semantic understanding, the

static and dynamic data exchanges through CIM/RDF/XML

files, evolution of CIM, and more such case studies have

2

been reported in [2], [4]–[7]. Converters from proprietary to

CIM format using object oriented methodologies [8] and using

database methodologies [9] have also been developed. With

these CIM developments, it becomes an attractive choice for

flexible and persistent representation of data in both object-

oriented and relational database paradigms.

Although CIM has been developed as an exhaustive model

in the last two decades span, efforts are still being made to

extend the CIM to account for various factors such as market

models and graphics models [10]–[13]. CIM is already gaining

worldwide recognition and acceptance as a standard for power

system domain [14]. The power system applications of CIM

at transmission and at distribution level are described in [15]–

[17]. Thus CIM plays a significant role in the power system

industry. An implicit list of several benefits from development

and utility perspectives are as follows.

A. Benefits from Development Perspective

1) Model driven approach and a systematic development

paradigm comprising of common structure and common

semantics improves application design time complexity

and achieves better compatibility. This approach can

also avoid many semantic compatibility errors which are

otherwise difficult to find and correct.

2) CIM oriented software systems (COSS) store informa-

tion in CIM format, which removes the extra layer of

CIM translation during information exchange among

applications.

3) Improves the confidence level in information retrieval

since standard mapping is followed, eliminating the need

for interpretation of values for which documentation is

incomplete.

4) Faster implementation of application functionality and

business processes in a model driven paradigm due to

the use of proven existing technology and architectural

solutions.

5) Smoother processes for maintaining and extending ex-

isting applications due to openness and standardization

in architecture.

6) Redundancy due to replicated or overlapping data in

multiple applications can be avoided following a model

driven approach.

B. Benefits from Utility Perspective

1) Rapid integration of application systems and information

will improve utility’s capability to respond quickly to

business changes.

2) Due to standardized commercial-off-the-shelf (COTS)

applications, integration of utility functionality and busi-

ness applications can be faster and smoother.

3) Flexibility to plug-in and change third party applications.

4) Easy and fast access to intricate relationship of every

object or asset of a utility.

With this foundation of CIM, the application integration

architecture with CIM-oriented database for control centers

is described in the subsequent sections of the paper.

Fig. 1. Migration Architecture for Movement Towards Future Control Centers

III. CONTROL CENTER MIGRATION

In the above sections we have identified the problems faced

by present control centers. While addressing these problems,

it is desirable to establish a migration architecture to pave

the way towards a smooth migration of legacy control centers

to seamless control centers. Therefore the paper contemplates

on the present control center issues, and envisions an archi-

tecture for future control centers with design objectives such

as seamless integration of utility applications, availability of

information in a common model, ability to integrate third-party

applications, and seamless data exchange in inter-utility and

intra-utility application networks.

A bird’s-eye-view of the proposed architecture is depicted

in Fig. 1. The picture shows a vertical and horizontal section

looking like the mathematical symbol ∞ (infinity). The shape

infinity is depicted to suggest that every layer is open to

unbounded extension due to standardization. Further they can

inter-operate through the utility integration bus (UIB). The

vertical infinity ring is envisaged to accommodate power

system applications and third-party applications. The hori-

zontal infinity ring accommodates more general information

exchangers and CIM based adapters. These infinity layers are

integrated through a standardized UIB.

The architecture comprises of CIM oriented database repos-

itory (CIMODB) layer encompassing the third-party applica-

tion database layer. The development of CIMODB for third-

party databases mainly include three steps of identification of

third-party objects to be migrated, their mapping on the CIM

class model, and the development of converters which can

be plugged into the CIMODB to convert a third-party non-

standardized database into CIMODB. If a mapping fails to

identify CIM classes due to lack of suitable CIM classes, a

local or global extension in CIM can be proposed.

With this model as the basis, the paper demonstrates a spe-

cific solution architecture which is applied to two case studies.

The first case study brings out a process of smooth integration

of information, application and the graphical displays, while

the second case study suggests a migration path from legacy

3

Fig. 2. Architecture for CIM Integrated Applications in a Control Center

to seamless control centers.

IV. UTILITY APPLICATION INTEGRATION ARCHITECTURE

The architecture depicted in Fig. 2 demonstrates a model

for integrating power system applications with CIM oriented

database in a web enabled framework. Solution characteristics

such as service orientation, openness, seamless application

integration, interoperability, flexibility, scalability, extensibility

and semantic message payload formats are identified as signif-

icant aspects of future power system control centers. The pro-

posed architecture comprising four services with eight layers

is designed keeping view the aforementioned solution charac-

teristics. The input services include configuration, CSV-XML

conversion, CIM RDF XML and database adapter layers. The

output services include application and presentation layers.

The data services manage the storage layer over a relational

database. The validation service includes CIM conformance

through a CIM XML validation adapter to validate CIM RDF

XML files.

The implementation of this architecture is carried out via

a coordinated use of various standards and open source tech-

nologies such as Common Information Model (CIM), Unified

Modeling Language (UML), eXtensible Markup Language

(XML), Comma-separated Values (CSV) [18], Scalable Vector

Graphics (SVG) [19], PHP [20], MySQL [21], JAVA and

Python [22]. These are supported by consortia such as IEC

TC 57, W3C, OMG and the open source community. The

description of the eight layers in the proposed architecture

shown in Fig. 2 is given below.

1) Configuration & Stream Layer: This layer consists of

configuration information pertaining to network static data,

network graphical coordinates, network profile data and net-

work dynamic data streams. This layer facilitates customiza-

Fig. 3. Sequence Diagram for CIM/XML, SLDx Generator

tion to the users of the software system. In our implemen-

tation, we have used the CSV file format for representing

the information in the configuration layer as shown in the

figure. Network static data includes information about static

configurations. Network dynamic data represents dynamic

values of the components included in network static data such

as breaker and disconnecter status, and values of frequency,

voltage, phase angle, current and power flow. Network graphi-

cal coordinates represent position of each power system object

on a canvas. Network profile data includes the corresponding

static information such as CIM classes, CIM attributes, and

CIM relationships of the above mentioned network static and

dynamic information.

2) Platform Specific CIM Classes and Validation Layer:

The layer includes CIM related processors, converters, and

validator. The CIM XML validator validates the CIM XML

files for conformance in accordance with the standard IEC

61970-552 [23]. Any power system application would only

be needing some of these UML classes. A profile structure is

4

Fig. 4. Sequence Diagram for CIM/XML Graphic Generator

created for each application. A profile represents application

requirement in CIM. The real world online power system

data can then be incorporated into XML bindings confirming

to these associated schema corresponding to the profiles. A

schema file represents rules and definitions of XML tags. The

user creates the CIM profiles using CIM profile creator of

which the output is sent to XSD generator. The XSD format is

used to represent the schema files corresponding to the domain

profile models.

3) CSV-XML and CIM/XML Layers: The layer CSV-XML

imports CSV configurations and converts them into the

CIM XML format. It uses XSD schema files which capture

structural representation of the XML. The layer includes

CIM/XML static file creator, CIM/XML dynamic file creator

and CIM/XML graphic file creator for converting the config-

uration fils defined in the above configuration layer. The con-

verters import the configuration files and refer schema file to

generate the corresponding CIM/XML files. The interactions

of CIM/XML converter are shown in Fig. 3. The CSV/XML

layer includes CIM XML static files, dynamic files and graphic

files. This CIM XML database will be used to exchange the

information across control centers.

4) Database Adapter and Database Layers: This layer

is defined in order to provide data integrity, management

and consistent access to other plug-in applications. The first

purpose is to accept data from data sources in CIM XML

format and send it to data archives. The second purpose is to

retrieve the data from archives and make it available in CIM

XML format for plug-in applications. The database adapter

layer includes CIM XML converters for converting CIM XML

file database to relational database with the database operations

such as create, read, update and delete. The database layer

includes relational database storage system to archive CIM

XML file database. We have earlier presented the CIM oriented

database schema in [24].5) Application layer: The data configuration and data in-

tegration layers form a major portion of the proposed archi-

tecture. On the basis of these layers, plug-ins can be built

independently by third party developers. Thus the architecture

addresses the problem of achieving interoperability at the ap-

plication level mentioned in above sections. This layer includes

applications such as scalable vector graphics (SVG) converter

for generating graphic network diagram files, cascade style

sheets (CSS) [25] theme generator for defining styling arti-

facts, topology processor for obtaining bus branch model from

node breaker model of a power system network and load

flow adapter for integrating proprietary load flow softwares

that compute power flows over lines. The interactions of SVG

converter which generates SVG files are shown in Fig. 4.

6) Presentation Layer: The purpose of this layer is to

provide web enabled aforesaid services for integrating widely

spread power system applications. This approach is aimed

at facilitating remote execution, access and management the

myriad power system software application systems. The layer

comprises of components which act as front-end clients and

a back-end presentation server. The presentation server for-

mulates and forwards the concerns of the presentation clients

to the application layer. We have used a pull model approach

wherein the client sends a request in order to obtain a response

from the server. The request is sent in an encrypted form of

XML-http-request and the data is decrypted by the server-side

php scripts. The application programs located at the server

side are executed in accordance with the decrypted request

and subsequently the results are sent back to the client in a

html format.

V. CASE STUDY AND RESULTS

A. Case Study: WR 400 kV Network

In accordance with the scheme of developing CIMODB

from third-party databases discussed in Section III, in this

case study, we analyzed western region (WR) 400 kV network

for migration of third-party database into the proposed CIM

based architecture. The western region load dispatch center

(WRLDC) maintain their network through a GE SCADA

system. As per the proposed architectural solution strategy,

the following three steps were followed. Firstly, every ob-

ject in the WR 400 kV network under consideration was

analyzed to identify the objects that need to be mapped

to CIM, specifically those which are exchanged with other

control centers. Secondly, these objects were mapped to CIM

classes identifying the relevant attributes and relationships.

The second step is referred to as CIM profile creation. From

the profile, the XML schema was derived from the CIM

profile of the network model by using the XSD generator as

shown in Fig. 2. Thirdly, for the data conversion which is

represented in PSS/E system format, a format-specific adapter

was developed for converting PSS/E format into CIM format

to finally generate CIM XML objects. The resulting CIM

XML objects are then stored into the CIMODB which was

mentioned in the Section IV.

The prototype system was implemented using Python and

XML. It is noted that the process of analyzing and mapping

5

Fig. 5. Maharashtra 400 kV Network

needed domain experts having a coherent knowledge of the

GE system and its functionality. Once the mapping process is

done, the remaining exercise mainly involves implementation

of the format-specific adapter. In this way as prescribed in

Fig. 2, migration towards CIM can be achieved.

B. Case Study: Maharashtra 400 kV Network

An objective of this study has been to demonstrate the

generation of CIM/RDF/XML domain data for the existing

400 kV Maharashtra network so that they can be processed

by applications. Also graphics information for the network

was generated as graphics data files which are then translated

into SVG format so that the entire network is visualized. The

case study was carried out by deploying actual but offline

data traces over a laboratory implementation confirming with

the proposed CIM oriented architecture. A description of two

applications implemented in this case study is provided below.

1) Web-enabled Network Topology Processing (NTP): The

topology processor is implemented in python environment in

accordance with the algorithmic schemes presented in [26]–

[28]. The web enabled NTP application is provided as a

service by integrating it with Apache server and PHP scripts.

A database schema presented in [24] is used for storing static

and dynamic network data (switch statuses, load and genera-

tion values), topology, and graphical coordinate information.

AJAX technology is used for facilitating asynchronous calls

to be sent to the server from the client, such as calls to report

status changes of circuit breakers manually initiated by the

user by clicking through the interactive display shown in Fig.

5. The strategy of integration of CGI, AJAX and SVG into

client-server systems that is followed in this work is as de-

scribed in [29]. Common gateway interface (CGI) is a software

technology which is used to interface external applications

to the server. In this work, AJAX technology was used to

track the user initiated changes in the substation or network

diagrams and then the CGI scripts are used accordingly to

Fig. 6. Queries for Load Flow API

trigger the associated application such as topology processing

and load flow.

In the example shown in Fig. 5, as a result of toggling

status of a few switches, three islands are formed on the

network. The islands are visualized in different colors. In this

case study, the size of configuration file is 1428 KB, and the

elapsed time of generating CIM-RDF-XML and CIM graphics

XML files are 0.164 seconds and 0.128 seconds respectively.

The sizes of these generated files are 1562 KB and 1872 KB

respectively. The SVG files for the network diagram and for

all the substation diagrams are generated on-line whenever

the user triggers the click event on the browser. The SVG file

sizes and their generation times are as follows: The elapsed

time of generating the graphics SVG file for the network

diagram is 0.143 seconds and the file size is 72.9 KB. The

elapsed time of generating the graphics SVG file for each

substation diagram varies from 0.109 to 0.137 seconds, and

the file sizes are 23.4 KB to 39.8 KB in accordance with the

number of graphical objects in the diagram. In addition, the

6

time of taken by only the topology processor component is

0.112 seconds. A computer with the dual operating system

(windows 7 and ubuntu 13.04) and 4GB RAM is used for

executing the developed programs, and preparing the set-up

of both the database and the web server.

2) Load Flow Application: A load flow analysis is also

carried out by integrating Matpower, a load flow software

Matlab package into the framework. The example queries

shown in Fig. 6 are used to retrieve the required values from

the database (schema presented in [24]) for use by the load

flow application. An adapter is developed for conversion of

CIM/XML files to MatPower compatible format.

VI. CONCLUSION

Though the concept of CIM standard for coordinated use

of SCADA/EMS application systems has been dealt with

in the literature, the information on smooth migration and

implementation is scarce. Such a migration to open design and

implementation needs a paradigm shift in the basic structure.

Utilizing the recent advancements in technologies and archi-

tecture philosophy, the paper demonstrated an architecture and

related implementation aspects for migration and subsequent

application development towards future control centers. The

proposed architecture is CIM based. The solution organizes

into horizontal and vertical extensible rings with database

layers at the core.

A demonstration implementation of the architecture has

been developed with a coordinated use of open source, pro-

prietary (PSS/E) and in-house (code developed) software. A

case study of WR 400 kV network is implemented as a

demonstration of migration of a legacy utility to a CIM

based seamless utility. Another case study of 400 kV 20-

substation Maharashtra network model is implemented over

this implementation to elaborate integration of application and

web enabled visualization. Also a case study of 400 kV 20-

substation Maharashtra network model is implemented over

this implementation to elaborate integration of application

and web enabled visualization. The design of CIM oriented

application integration architecture is envisaged to be advan-

tageous from the perspectives of developers and the utilities

from the point of view of compatibility, interoperability, user-

friendliness, extensibility and openness.

ACKNOWLEDGMENT

The authors like to thank the officials of Maharashtra

State Load Dispatch Center (MSLDC) and Western Region

Load Dispatch Center (WRLDC) for providing the data of

the practical power system networks. Thanks are due to Dr.

Pradeep for his valuable technical suggestions.

REFERENCES

[1] NIST, “Smart grid conceptual model - national institute of standards andtechnology,” 2013. [Online]. Available: http://collaborate.nist.gov/twiki-sggrid/bin/view/SmartGrid/SGConceptualModel

[2] S. Lee, “The epri common information model for operation and plan-ning,” in Power Engineering Society Summer Meeting, 1999. IEEE,vol. 2, 1999, pp. 866 –871 vol.2.

[3] IEC TC 57, Energy management system application program interface

(EMS-API), Part 61970-301, 2nd ed., 2011.

[4] G. Huang and N.-K. Nair, “Static and dynamic cim-xml documents forproprietary ems,” in Power Engineering Society General Meeting, 2003,

IEEE, vol. 2, Jul. 2003, p. 4 vol. 2666.[5] J. Britton and A. deVos, “Cim-based standards and cim evolution,”

Power Systems, IEEE Transactions on, vol. 20, no. 2, pp. 758 – 764,May 2005.

[6] A. McMorran, G. Ault, C. Morgan, I. Elders, and J. McDonald, “Acommon information model (cim) toolkit framework implemented injava,” Power Systems, IEEE Transactions on, vol. 21, no. 1, pp. 194 –201, Feb. 2006.

[7] A. McMorran, “An introduction to iec 61970-301 & 61968-11: The com-mon information model,” Technical Report, University of Strathclyde,

Glasgow, UK, pp. 1 – 42, Jan 2007.[8] A. McMorran, G. Ault, I. Elders, C. Foote, G. Burt, and J. McDonald,

“Translating cim xml power system data to a proprietary format forsystem simulation,” Power Systems, IEEE Transactions on, vol. 19, no. 1,pp. 229 – 235, Feb. 2004.

[9] J. Wu and N. Schulz, “Overview of cim-oriented database design anddata exchanging in power system applications,” in Power Symposium,

2005. Proceedings of the 37th Annual North American, Oct. 2005, pp.16 – 20.

[10] E. Haq and E. Dobrowolski, “Cim-based network models in a multi-vendor environment at caiso,” in IEEE Power Engineering Society

General Meeting, Jun. 2007, pp. 1–2.[11] X. Wang and S. V. Ausdall, “Representing Business Data Semantics In

CIM using UML,” PSCE, 2006.[12] A. McMorran, R. Lincoln, and E. Wuergler, “Cim graphics exchange,”

in 2011 Proc. IEEE/PES Power Syst. Conf. Expo. (PSCE)., Mar. 2011,pp. 1–3.

[13] G. Ravikumar, Y. Pradeep, and S. Khaparde, “Graphics model for powersystems using layouts and relative coordinates in cim framework,” Power

Systems, IEEE Transactions on, vol. 28, no. 4, pp. 3906–3915, 2013.[14] CIMUG, “Introduction to cim and its role in the utility enterprise data

preparation, exchange, integration, and enterprise information manage-ment,” Tutorial, CIM User Group Meeting Vesteras, Sweden, Jun. 2008.

[15] X. Wang and N. Schulz, “Development of three-phase distribution powerflow using common information model,” in Power Engineering Society

Summer Meeting, 2000. IEEE, vol. 4, 2000, pp. 2320 –2325 vol. 4.[16] Y. Zhou, W. Zheng, T. Xu, and L. Fu, “Study on design and maintenance

methods of cim-based spatial database for distribution network,” inInformation Science and Engineering (ICISE), 2010 2nd International

Conference on, dec. 2010, pp. 4062 –4066.[17] J. Y. Tian, Y. Zhu, Z. C. Liang, and H. Wei, “A method for online

calculation of line loss in distribution networks based on cim,” inElectricity Distribution (CICED), 2010 China International Conference

on, sept. 2010, pp. 1 –4.[18] Y. Shafranovich, “Comma-separated values (csv) files,” 2013. [Online].

Available: http://tools.ietf.org/html/rfc4180[19] C. Lilley and D. Schepers, “Scalable vector graphics (svg),” 2013.

[Online]. Available: http://www.w3.org/Graphics/SVG/[20] “Php manual,” 2013. [Online]. Available: http://php.net/[21] “Mysql manual,” 2013. [Online]. Available: http://www.mysql.com/[22] “Python manual,” 2013. [Online]. Available: http://www.python.org/[23] Draft IEC 61970, IEC Standard Energy management system applica-

tion program interface (EMS-API) – 61970-55x:CIM Based Graphic

Exchange Format (CIM/G). under proposal by Chinese NC, 2011.[24] G. Ravikumar, S. A. Khaparde, and Y. Pradeep, “Cim oriented database

for topology processing and integration of power system applications,”in Accepted for Proc. 2013 IEEE Power Energy Soc. Gen. Meet., Jul.2013, pp. 1–5.

[25] B. Bos, “Cascading style sheets (css),” 2013. [Online]. Available:http://www.w3.org/Style/CSS/

[26] A. McMorran, G. Ault, I. Elders, C. Foote, G. Burt, and J. McDonald,“Translating cim xml power system data to a proprietary format forsystem simulation,” IEEE Trans. Power Syst., vol. 19, no. 1, pp. 229–235, Feb. 2004.

[27] C. Wang, Q. Chen, R. Bo, X. Huang, M. Hu, and L. Yang, “A new cim-based cross-platform graphic system for power system applications,” inProc. 2008 IEEE 3rd Int. Conf. Electr. Util. Deregulation, Restructuring,

Power Technol. (DRPT), Apr. 2008, pp. 846–851.[28] Y. Pradeep, P. Seshuraju, S. Khaparde, and R. Joshi, “Cim-based

connectivity model for bus-branch topology extraction and exchange,”IEEE Trans. Smart Grid, vol. 2, no. 2, pp. 244–253, Jun. 2011.

[29] W. Zhangjin, H. Xingwen, D. Ying, Z. Rui, and Z. Qingguo, “Acgi+ajax+svg based monitoring method for distributed and embeddedsystem,” in Proc. 2008 IEEE 1st Int. Conf. Ubi-Media Computing, Aug.2008, pp. 144–148.