• Journal of Electrical Engineering and Technology
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• v.9 no.2
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• pp.655-661
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• 2014

In this paper, a new two dimensional (2D) analytical modeling and simulation for a surrounding gate tunnel field effect transistor (TFET) is proposed. The Parabolic approximation technique is used to solve the 2-D Poisson equation with suitable boundary conditions and analytical expressions for surface potential and electric field are derived. This electric field distribution is further used to calculate the tunneling generation rate and thus we numerically extract the tunneling current. The results show a significant improvement in on-current characteristics while short channel effects are greatly reduced. Effectiveness of the proposed model has been confirmed by comparing the analytical results with the TCAD simulation results.

• Journal of the Korea Society for Simulation
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• v.7 no.1
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• pp.1-14
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• 1998

In this paper, we propose an efficient network communication scheme tailored to the network virtual reality(NVR) system. We first present the architecture and implementation of CVRAT (collaborative virtual reality authoring tool). The design goal of CVRAT is to provide consistent and scalable shared virtual environments. To achieve this goal, we classify the network messages according to their reliability and latency requirements. These conflicting requirements lead us to conceive a heterogeneous communication scheme which provides the unicast and three different multicast transport services; unreliable multicast, receiver-driven reliable multicast, fast reliable multicast. Each protocol has trade-offs in reliability, latency and bandwidth usage. The characteristics are analyzed by several experiments. Finally, applying this communication method to multi-participant battle-field tank simulation, we show the efficacy of proposed heterogeneous transport mechanism.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.459-463
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• 2001

We model and simulate master-driven TDD wireless communication systems, e.g., Bluetooth systems. We model the Bluetooth system and use the BONeS simulation tool to conduct event-drivers simulations. In order to support more than seven slave devices in a piconet, a park mode is considered and modeled. We evaluate the performance, i.e., throughput and delay, using simulations when multi-connections (bath ACL and SCO connections) are present in a piconet. We show that the data rate of ACL connections may be less than 20 kbps when SCO connection(s) and more than six ACL connections are jointly supported in a piconet. In addition, if up to five ACL connections are supported, the average delay is shown to be maintained less than 20 msec. Our results can serve as a guideline to the design of master-driven TDD wireless communication systems with performance requirements.

• Journal of the Korea Society for Simulation
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• v.3 no.1
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• pp.115-124
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• 1994

In this paper, we have developed a performance analysis tool for communication networks called COMNAS. COMNAS analyses the performance of wide area networks such as Korea Educational Network and Korea Research Environment Open Network which include local area networks such as Ethernet and Token Ring. COMNAS consists of model constructor, simulation implementor, output analyzer and user interface. Attributes of communication networks for modeling either have default values or are entered by user as object units, and implementation of simulation is automatically proceeded by user interface. Ouput results obtained by COMNAS are the status of node, link and entire network such as mean message transmission delay, throughput, utilization, and so on, and they can be selectively obtained upon the request of the user.

• Proceedings of the Korea Society for Simulation Conference
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• 2005.05a
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• pp.10-14
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• 2005

IEEE 802.15.4 low-rate Wireless Personal Area Networks(WPAN) are expected to provide ubiquitous networking between small personal/home devices and sensors with low power consumption and low cost features. The technology employs special CSMA/CA (Carrier Sense Multiple Access/collision Avoidance) to save power consumption for small or portable WPAN-enabled devices. In this paper, we simulation the slotted CSMA/CA of IEEE 802.15.4 MAC and evaluate its performance limit in order to grasp the characteristics of Medium Access Control (MAC) of IEEE 802.15.4 WPAN.

• Journal of the Korea Society for Simulation
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• v.6 no.2
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• pp.71-79
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• 1997

In this paper, operations system was designed for the centralization of data processing of various state information from the facilities of mobile communication network. And the system performance experimental system module was measured and analyzed from the designed experimental system module. The configuration of system design was presented with the centralized type to monite and control the facilities of mobile communication network in the central office. The communication process design of the internal system was implemented with the resource of message queue having a excellent transmission ability for processing of a great quantity of information in the inter-process communication among communication resources of UNIX system. The process with a server function from the internal communication processes was constructed with a single server or a double server according to the quantity of operations and implemented with the policy of the presented server. And then, we have measured performance elements in accordance with the change of input parameters from the designed experimental module : response time, waiting time, buffer length, the maximum quantity existing in message queue. And from these results, we have compared and analyzed the system state each server algorithm according to performance variations.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.4
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• pp.439-446
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• 2014

This study introduces about the analysis, verification and implementation of Digital Communication Satellite transponder. Through the pre-performance analysis of each component by the circuit level simulation, each component's performance was checked whether satisfying the specifications. When each of the components was connected in order, System's performances were evaluated through system harmonic balanced simulation whether satisfying the specifications. Through pre-analysis of the system performance, specification of each component was defined. On the basis of that specification, Components which comprise the Digital Communication Satellite repeater were manufactured, and finally, the overall system performance check was made by integrating the components of Digital Communication Satellite transponder.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.8
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• pp.883-888
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• 2014

Simulation is now using in various area as an effective decision analysis tool in complex environment of today. But, There is a focus to the simulation model development and execution better than result analysis. This article will emphasis to the importance of result analysis apart from model development in simulation, and will use R package for profit optimization simulation. R has a various function in statistic analysis and data manipulation, graphic display. So this research can show the value of R as a tool for simulation.

• Journal of the Korean Graphic Arts Communication Society
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• v.11 no.1
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• pp.57-69
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• 1993

Currently, Computer-To-Plate printing system comes into wide use, an accurate color simulation system is demanded. This paper is described some basic operational expressions known in the simulation of colors by use of halftone dots, and is proposed improved color prediction of multicolor halftone, The experimental results show that proposed color predict Eq. is useful and valid in predicting the color reproduction of multicolor halftone.

• Journal of Advanced Navigation Technology
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• v.13 no.3
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• pp.351-357
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• 2009

In this paper, we studied an efficient inter-working method in which QualNet network simulator can import WAVE channel model and physical layer simulation module pre-designed by Matlab tool. At first, we investigated physical layer and communication medium simply designed in QualNet, then we suggested practical method for QualNet network simulator to adopt different type of physical layer simulation module in which detailed multi-path fading channel model and IEEE802.11p communication modem are designed. This work should be applied to linked simulation between upper layer and lower physical layer for total simulation from higher layer to lower physical layer related to next generation DSRC/WAVE specification.