• Journal of computational fluids engineering
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• v.13 no.1
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• pp.7-13
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• 2008

Several high resolution schemes such as OSHER, MUSCL, SMART, GAMMA, WACEB and CUBISTA are comparatively studied with respect to the accurate capturing of fluid interfaces throughout the application to two typical test cases of a translation test and a collapsing water column problem with a return wave. It is accomplished by implementing the high resolution schemes in the in-house CFD code(PowerCFD) for computing 3-D flow with an unstructured cell-centered method and an interface capturing method, which is based on the finite-volume technique and fully conservative. The calculated results show that SMART scheme gives the best performance with respect to accuracy and robustness.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.1
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• pp.23-29
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• 2008

Two high resolution compressive schemes, CICSAM(Ubbink, 1997) and HRIC(Muzaferija & Peric, 1999), in interface capturing method are reviewed briefly with respect to the extended forms suitable for unstructured meshes. And then those are applied to three typical test cases of translation test, shearing flow test and collapsing water problem with an obstacle. It is accomplished by implementing the high resolution schemes in the in-house CFD code(PowerCFD) for computing 3-D flow with an unstructured cell-centered method, which is based on the finite-volume technique and fully conservative. The calculated results show that CICSAM is better than HRIC with respect to accuracy and robustness, although either scheme can be used as a good choice for free surface or two-phase flow simulation.

• ETRI Journal
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• v.25 no.1
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• pp.25-33
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• 2003

This paper describes interactive dynamic simulation schemes for articulated bodies in virtual environments, where user interaction is allowed through a haptic interface. We incorporated these schemes into our dynamic simulator I-GMS, which was developed in an object-oriented framework for simulating motions of free bodies and complex linkages, such as those needed for robotic systems or human body simulation. User interaction is achieved by performing push and pull operations with the PHANToM haptic device, which runs as an integrated part of I-GMS. We use both forward and inverse dynamics of articulated bodies for the haptic interaction by the push and pull operations, respectively. We demonstrate the user-interaction capability of I-GMS through on-line editing of trajectories for 6-dof (degrees of freedom) articulated bodies.

• 한국전산유체공학회:학술대회논문집
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• 2006.10a
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• pp.51-56
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• 2006

Several high resolution schemes such as OSHER, MUSCL, SMART, GAMMA, WACEB and CUBISTA are applied to two typical test cases of a translation test and a collapsing water column problem for the accurate capturing of fluid interfaces. It is accomplished by implementing the high resolution schemes in the in-house CFD code(PowerCFD) for computing 3-D flow with an unstructured cell-centered method, which is based on the finite-volume technique and fully conservative. The calculated results are found to show that SMART scheme gives the best performance with respect to accuracy and robustness.

• ETRI Journal
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• v.27 no.1
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• pp.81-88
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• 2005

In this paper, interface circuits that are suitable for point-to-point interconnection with an over 1 Gbps data rate per pin are proposed. To achieve a successful data transfer rate of multi-gigabits per-second between two chips with a point-to-point interconnection, the input receiver uses an on-chip parallel terminator of the pass gate style, while the output driver uses the pullup and pulldown transistors of the diode-connected style. In addition, the novel dynamic voltage level converter (DVLC) has solved such problems as the access time increase and valid data window reduction. These schemes were adopted on a 64 Mb DDR SRAM with a 1.5 Gbps data rate per pin and fabricated using a 0.10 ${\mu}m$ dual gate oxide CMOS technology.

• Structural Engineering and Mechanics
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• v.6 no.7
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• pp.801-815
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• 1998

An overview of an analytical model to predict mortar joint failure in unreinforced masonry (URM) structures is presented. The validity of the model is established by comparison with experimental results at element level as well as structure level. This model is then used to study the behavior of URM walls and two commonly used retrofitting schemes. Finally, effectiveness of the two retrofitting schemes in increasing strength and stiffness of existing URM walls is discussed.

• Proceedings of the KIEE Conference
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• 2008.04a
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• pp.163-165
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• 2008

In this paper we compare performance of exponential effective SINR mapping (EESM) with traditional actual value interface (AVI) approach for various modulation and coding schemes (MCS) in terms of coded bit error rate (BER) or block error rate (BLER) using different transmission schemes. This paper provides explanation and comparison of the two algorithms for single input single output (SISO), and single input multi-output (SIMO, 1X2) in OFDM systems. We calibrate the value of beta ($\beta$) in EESM using large number of channel realizations, here $\beta$ is a calibration constant. This paper also presents importance of beta value in EESM and how it improves the performance of OFDM wireless systems. We propose different modulation and coding schemes. Here we consider Standford university interim (SUI) channel models. Furthermore this paper also shows the detail observation of the two algorithms. Finally the conclusion review given for short summary.

• The KIPS Transactions:PartC
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• v.16C no.3
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• pp.383-392
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• 2009

Next generation network (NGN) is a packet-based converged network to support session and non-session services in QoS-enabled broadband transport network. QoS based resource control must be defined to support differentiated services for various network users in NGN. This paper defined parallel control schemes for NGN resource control interfaces to minimize session and resource control delays. We simulated the existing and proposed NGN control schemes to measure and analyze control delays and completion ratios. By arrival rate of 120 in two-phase resource control, we checked out that completion ratios of sequential and parallel schemes achieved 100%, and the control delay of parallel scheme was improved by about 21.5% compared to that of sequential scheme.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1602-1605
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• 2002

Communication schemes are currently changing from circuit switched towards packet switched. These changes enable access to Internet and multimedia services in wireless network. Provision of real-time IP services in air interface introduces relatively large overhead in RTP/UDP/IP headers. To reduce the overhead, the header compression schemes are required. There exist two header compression schemes (CRTP, ROHC) which are IETF standards. We propose Context-ID detection method which reduces more efficiently the packet loss rate than two existing schemes. Its performance in WCDMA system environment is evaluated for CRTP and ROHC schemes.

• ETRI Journal
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• v.18 no.4
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• pp.229-244
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• 1997

Realization of the economical, reliable, and efficient ATM interface block becomes an important key to development of the ATM switching system when we consider new issues raised recently. In this paper, we summarize requirements for the ATM interface block and present the UNI (User Network Interface)/NNI (Network Node Interface) architecture to meet these requirements. We also evaluate the performance of the multiplexer adopting the various multiplexing schemes and service disciplines. For ATM UNI/NNI interface technologies, we have developed a new policing device using the priority encoding scheme. It can reduce the decision time for policing significantly. We have also designed a new spacer that can space out the clumped cell stream almost perfectly. This algorithm guarantees more than 99 % conformance to the negotiated peak cell rate. Finally, we propose the interface architecture for accommodation of the ABR (Available Bit Rate) transfer capability. The proposed structure that performs virtual source and virtual destination functions as well as a switch algorithm can efficiently accommodate the ABR service.