• The KIPS Transactions:PartC
• /
• v.14C no.6
• /
• pp.525-536
• /
• 2007

Network Control Platform(NCP) and Qualify of Service Switch(QSS) are being developed to realize centralized control and management technology, which is essential for guaranteeing traffic engineering and service quality in a next generation network. This paper adopts a parallel mechanism, and a thread and object pool to achieve high-speed connection management in the existing SNMP interface between NCP and QSS. We built up a connection management test-bed in laboratory environment to validate the functionality of high-speed connection management. We also measured and analyzed a performance of connection setup delay and a completion ratio using the test-bed. We ascertain that the parallel mechanism and the object pool are the most important performance parameters to achieve high-speed connection management in the SNMP interface between NCP and QSS.

• Journal of Korea Multimedia Society
• /
• v.9 no.1
• /
• pp.89-100
• /
• 2006

The introduction of GSMP open interface to OBS network can materialize to separate the transport plane and the control plane in OBS network. This makes the implementation of OBS switches simple and provides various flexibility. However, the introduction of open interface will cause the connection setup delay because of the additional processing overhead of open interface protocol. Also, in GSMP based network, the location of network management functions are not defined explicitly and the research result about the OBS network management is almost nothing. This paper proposes a parallel connection setup mechanism using centralized connection control server to minimize connection setup delay in OBS network with GSMP open interface and defines managed objects to support connection, configuration, performance, and fault management for the management of OBS network with GSMP open interface. This paper also proposes a distributed network management model, in which the above managed objects are distributed in a controller and an OBS switch according to network management functions. We verify the possibility of OBS control and network management by implementing network management function using proposed parallel connection setup mechanism and distributed network management model.

• International Journal of Highway Engineering
• /
• v.15 no.6
• /
• pp.49-60
• /
• 2013

PURPOSES : The evaluation of the pavement condition of the asphalt concrete pavement of No. 2 runway of Inchon International Airport through PMS, a supporting system for making a decision of pavement, maintenance and repair, was made, and the proper time for repair according to the PCI reduction rate was suggested. METHODS : By comparing and analyzing the evaluation results of pavements built in 2009, 2010, 2011, PCI change in each facility (No. 2 runway, C parallel taxiway, connection taxiway) was calculated. By applying the calculated change to PCI deduction rate model, the pavement condition of the target sections was estimated, and then the necessary section and time for repair were chosen. RESULTS : After careful consideration of the time for pavement and maintenance, based on the result of PCI prediction, it was estimated that the southern takeoff and landing section of No. 2 runway was required to be repaired in 2012; connection taxiway in 2013; and C parallel taxiway in 2014; however, the section which is the main moving route of connection taxiway and C parallel taxiway was needed to be repaired in 2012. CONCLUSIONS : For maintenance and repair of airport pavements, the optimal alternative should be chosen by considering economics and operability, via examining the time for repair and the aspect of management all together on the basis of this study.

• Journal of Information Technology Services
• /
• v.8 no.1
• /
• pp.193-202
• /
• 2009

Cloud computing emerges as a new computing paradigm which targets reliable and customizable services. The term builds on decades of research in virtual machine, distributed and parallel computing, utility computing, and more recently networking, web service, and software as a service. In this paper, we provide a seamless connection migration of web services. This is useful for cloud computing environment in which many client terminals have mobility. With the wireless internet facility, those mobile users can move place to place during internet communication. Therefore, we provide solutions to the two major problems in current virtualization based migration: communication failure problems and connection re-establishment. Communication channel flushing by zero window notification helps to resolve the communication failure problems and TCP port inheritance prevents connection re-establishment errors during socket reconstruction. Thus, our web service migration facility is now able to preserve open network connections, and even for server sockets. This is a highly transparent approach, in that we did not Introduce additional messages for channel flushing and did not make any modification to the TCP protocol stack. Experimental results show that the overhead due to connection migration of web services is almost negligible when compared with time to take the conventional web service migration.

• 한국태양에너지학회:학술대회논문집
• /
• 2008.04a
• /
• pp.43-48
• /
• 2008

Through simulations and field experiment on A.C. parallel operation of both Utility Interactive Photovoltaic System and Diesel Engine Revolving Field Type Synchronous Generator, following factors have been found. First, the inverter should be operated in three modes of frequency(mode.1: ${\pm}$0.3Hz, mode.2: ${\pm}$1Hz, mode.3: ${\pm}$2Hz) as default, considering properties of operating Synchronous Generator. Second, as a result of supplying 13.5kW of residual power, it has been found that Synchronous Generator takes the power input only as reactive power, because it was electrically stable with frequency of 60.14Hz and high voltage of 222.3V even when power factor was -0.94. Besides, it was mechanically stable, too, because the quake, noise, and temperature of Synchronous Generator in this case were 7.5mm/s, 97dB, and $6^{\circ}C$ respectively, which were lower than normal load connection of 145.6kW; 11.03mm/s. Thus, load share of Revolving Field Type Synchronous Generator reduces according to the supply of Photovoltaic System to the load power. In this experiment, 200kW of Synchronous Generator and 40kW of Photovoltaic System were operated in parallel. The load share was 20% in maximum. and 11.1lit/hr of fuel was saved.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.25 no.9
• /
• pp.723-726
• /
• 2012

A current intensity convertible CLD chip was fabricated using small and large FET cell configuration. Pinch-off current of 8.82 mA and 11.56 mA were obtained for small and large cell in the CLD chip, respectively. Constant current was fairly maintained until the breakdown voltage of 60 V. Measured knee voltage, $V_k$ were 3.8 V and 4.5 V for small and large cell, respectively. We configured current amplifying chip with parallel connection of each cells, by connecting 8 individual large cells in parallel network, 92.0 mA of current was obtained. The pinch-off constant current of CLD chip was varied very linearly with respect to the number of parallel connected cell.

• Proceedings of the KIEE Conference
• /
• 2001.10a
• /
• pp.245-248
• /
• 2001

Recently, with the advancement of internet network the system has been needed to be controllable and observable through internet at industrial workplace. In this study, we developed the digital timer which has a communication function to control and observe many kinds of devices by combining relay and timer used for each type of control panel to realize control solution based on internet to be easily applicable at workplace with low cost and adding 485 serial communication module to have parallel expansibility and safety. And, this system was experimented and designed for easy system management and status check from remote station through internet. appling the developed digital timer to parallel sequence control of motor. As the result of experiment, the circuit configuration would be more simplified than the existing, and it is expected that multi-connection control and monitoring can be simply implemented with low cost equipment at industrial workplace.

• Proceedings of the KIEE Conference
• /
• 2001.10a
• /
• pp.157-160
• /
• 2001

Recently, with the advancement of internet network the system has been needed to be controllable and observable through internet at industrial workplace. In this study, we developed the digital timer which has a communication function to control and observe many kinds of devices by combining relay and timer used for each type of control panel to realize control solution based on internet to be easily applicable at workplace with low cost and adding 485 serial communication module to have parallel expansibility and safety. And, this system was experimented and designed for easy system management and status check from remote station through internet, appling the developed digital timer to parallel sequence control of motor. As the result of experiment, the circuit configuration would be more simplified than the existing, and it is expected that multi-connection control and monitoring can be simply implemented with low cost equipment at industrial workplace.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.40 no.1
• /
• pp.185-198
• /
• 2015

This study drew performance management factors analyzed a causal link between acceptance and satisfaction of performance management to present the method for promoting acceptance on the performance management system that most of the public enterprises, government-affiliated organizations are implementing. To achieve this, qualitative analysis and quantitative analysis were conducted in parallel through in-depth case studies and surveys. The results of this study are as follows. First, the analysis of the performance management factors with preceding studies shows that performance management indicators, performance management operations and performance management communications. Second, from the causal relationship of performance management factors affecting performance management acceptance reveals that performance management operation has statistical significance. Third, the analysis of the effect of performance management factors on the management satisfaction shows that operation and indicator of the performance management have statistical significance and reflecting the performance indicators to business, adequacy of target level, training, system support and CEO's Leadership have been revealed as important variables to the management satisfaction. Fourth, the result of the analysis on casual connection between acceptance and satisfaction of the performance management shows that improving management acceptance has a direct impact on satisfaction because performance management receptiveness were deemed statistically significant. Fifth, the result of the in-depth case studies on improving performance management acceptance shows that public enterprises have been putting in an effort to design indicators and try to encourage internal member's involvement during the monitoring and evaluation. The quantitative analysis based on survey has turned out that performance management operation and performance management indicators have statistical significance. The qualitative analysis by in-depth analysis shows that public enterprises put a lot of effort to performance management indicators and communication between internal members. As a result, commitment to performance management operation is required to improve the performance management acceptance. In other words, a detailed implementation plan for training, information system support, and CEO's leadership has to be established and ought to be pushed.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.51 no.7
• /
• pp.279-285
• /
• 2002

This Paper deals with the economical equipment control which is used by internet network system at the industrial workplace. If the control devices can be accessed by internet, we can have the developed possibility of work conditions. in this paper, we presented the advanced digital timer which has a communication function to control and observe panel to realize control solution based on internet to be easily applicable at workplace with low cost, and we used RS-485 serial communication module to have parallel expansibility and safety. And, this system was experimented and designed for easy system management and status check from remote station through internet. As the result for experiment, the circuit configuration would be more simplified than the existing, and it is expected that multi connection control and monitoring can be simply implemented with low cost equipment at industrial workplace.