• Proceedings of the KSR Conference
• /
• 2005.11a
• /
• pp.293-298
• /
• 2005

In this paper, we introduced a simulator to visualize the driving scenery of newly developed train called the K-AGT(Korea Automated Guideway Transit). The simulator consists of mainly two parts; control system and display system. In the control system, user can control the driving speed of the K-AGT, the driving environment(day and night), the operation of the train door and the screen door and user's views(driver's view, left window view, right window view, passenger's view). In the display system, immersive driving scenery generated by stereoscopic head mount display system and 3 channel PDP display system are displayed. We are expect to utilize the system to share the idea among customer, designer and constructor and verify the operating condition of the K-AGT intuitively.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.17 no.3
• /
• pp.1035-1048
• /
• 2023

The IEEE 802.11 WLAN adopts a random backoff algorithm for its collision avoidance mechanism, and it is well known that the contention-based algorithm may suffer from performance degradation especially in congested networks. In this paper, we design an efficient backoff algorithm that utilizes a reinforcement learning method to determine optimal values of backoffs. The mobile nodes share a common contention window (CW) in our scheme, and using a Q-learning algorithm, they can avoid collisions by finding and implicitly reserving their optimal time slot(s). In addition, we introduce Frame Size Control (FSC) algorithm to minimize the possible degradation of aggregate throughput when the number of nodes exceeds the CW size. Our simulation shows that the proposed backoff algorithm with FSC method outperforms the 802.11 protocol regardless of the traffic conditions, and an analytical modeling proves that our mechanism has a unique operating point that is fair and stable.

• Korean Journal of Construction Engineering and Management
• /
• v.6 no.5 s.27
• /
• pp.128-138
• /
• 2005

The success of mergers and acquisitions(M&A) have been evaluated by either measuring ex ante expectations for the specified time period(Window) or assessing long term-based post operating performance (ex post operating performance). In this study, utilizing cumulative abnormal return(CAR) method, M&As which are observed in both domestic and U.S. construction industries were analyzed then research outcomes are compared. Analysis results indicate that stockholders of public construction companies did not realize significant economic gains from M&As. In other words, there was no synergistic gains from the construction M&As. Also, no significant performance difference was observed between related and unrelated diversifications.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.61 no.6
• /
• pp.797-803
• /
• 2012

In this paper, for minimizing the real-time operating load losses of the power transformer, a SCADA optimum operating system was developed, and the economic analyses on the test operation were performed. Transformer loss DB which reflects the economic integration operation criteria was constructed by referring the transformer manufacturer's loss data(iron loss, copper loss). Based on the loss DB, each substation transformer real-time loss was calculated according to the size of the transformer loads, and if integration or separation transformer operating conditions minimizing the loss are met, then a window pops-up and the dispatcher performs the substation equipments operation according to the procedure provided by this system. With the existing SCADA main program, the relation database of the substation facilities and integration/separation operation algorithm were developed and applied to Auto MTR Processor and pconn Processor Task module. Seven stations test data for seven months were analyzed for the economic analyses, and the results showed that Cost-Benefit ratio was 2.64, and IRR(Internal Rate of Return), 36%, which asserted the economic justification of the proposed system.

• Journal of Energy Engineering
• /
• v.25 no.4
• /
• pp.207-213
• /
• 2016

In this study, a thermal flow analysis was performed using the commercial code, ANSYS-FLUENT to reduce room temperature in a turbine building of power plant. The selected control volume of the operating floor and deaerator floor for the turbine building was respectively modelled. The skylight windows at the deaerator floor were employed for ventilation windows. Through the study, in the first we found that all window close of the deaerator floor is one alternative for reducing the temperature of the operating floor. The next thing we knew that for windows open at the front of the deaerator floor, the temperature of deaerator zone and crane zone can be respectively reduced to $1.5^{\circ}C$ and $1.6^{\circ}C$. In addition, for windows close at the rear of the deaerator floor, the temperature of deaerator zone and crane zone can be respectively reduced to 1.4 and $0.5^{\circ}C$. Therefore, it was concluded that a better choice is to open the front windows at deaerator floor to reduce the temperature of the entire deaerator floor having high temperature.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 1996.06a
• /
• pp.39-43
• /
• 1996

This paper presents the designing scheme of the duplexer for ground station using rectangular waveguide. The duplexer consists of 2-channel bandpass filters having asymmetrical inductive window and inductive post obstacles, coupled with H-plane Apertured-coupled junction, and operating in the frequency ranges of 14.5∼14.8GHz and 11.7∼12.0 GHz which are the DBS up/downlink for the domestic Ku-band ground station.

• Proceedings of the IEEK Conference
• /
• 1998.10a
• /
• pp.7-10
• /
• 1998

In implementing real time video on demand(VOD), the increase of user on internet causes a network traffic congestion. In this paper, we programmed a CGI able to login in VOD home for limiting the number of user in solving the problem, and also applied and adaptive multimedia synchronization technique for controlling video and audio data in a network. In addition, a real time multimedia player was designed and implemented in a personal computer operating at Window95/98/NT.

• Journal of information and communication convergence engineering
• /
• v.5 no.4
• /
• pp.305-310
• /
• 2007

In this paper, an analysis has been done on the performance of SCTP header compression by using Robust Reader Compression (ROHC)[1] method. And it is assumed that the operating mode for ROHC is unidirectional mode (U-Mode) and the possible states are IR and SO states. The throughput of SCTP packets in wireless link and the impact of size of W-LSB encoding window on throughput are discussed.

• Proceedings of the KSR Conference
• /
• 2000.11a
• /
• pp.491-498
• /
• 2000

This study was carried out about the design and FEM analysis of articulated Trailer car with aluminum bodyshell for Korean High Speed Train of maximum operating speed of 350㎞/h. The integral design by extra-long extruded sections made possible through the use of aluminium alloys and continuous window shape with skin were adopted in the design of aluminium bodyshell. Articulated structures in each trailer's end were bolted laterally on end structure. FEM analysis showed that the design satisfied the specified load criteria. This study describes process and result of development of aluminum trailer bodyshell for KHST.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.33B no.7
• /
• pp.51-59
• /
• 1996

The current network environment is composed of heterogeneous H/W and S/W resources. Integrating CSCW applications in such heterogeneous environments is highly complex. This paper describes the design and implementation of ASS (application sharing server) which supprot sharing of a single application between different operating systems. The ASS supports cooperative work among user group using its own window system (X-windwo or MS-windwos). We adopted improved managing heavy-weight data. ASS also provides development environment for vaious groupware application.