• Proceedings of the KSRS Conference
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• v.1
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• pp.212-215
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• 2006

This paper describes several reliability models to estimate COMS ground segment availability and shows assessed availability according to GS function. Due to a back-up concept among three ground center, SOC will have all H/W and S/W module to be installed in MSC and KOSC site. Therefore, all configurations and availability parameters for H/W and S/W modules in MSC and KOSC are assumed as equal with those in SOC, if related modules have same function. Prior to access availability over COMS GS function, Availability related to fundamental configuration such as series, parallel, partial operation, and module combined H/W and S/W is described. Consequently, all functions are expected to operate with more than 99% of availability.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.504-511
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• 2001

In this research, we developed a computer program that designs a centrifugal impeller and diffuser, and predicts the far-field noise from the impeller. To design the impeller optimally, the TEIS model, which was originally developed by Japkise(1985), and the mean-line analysis are combined to predict the performance and design the optimal impeller simultaneously. The geometric configurations are provided by a GUI software (iDesignComp). The noise from impeller can be computed by the rapid loading procedure, which generates a surface between two blades and calculates the pressure distributions on the suction and pressure sides. The steady loading noise is computed by the rotating dipole source distribution via Ffowcs Williams & Hawkings equation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.1
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• pp.12-20
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• 1997

Physical interconnect such as Printed Circuit Board(PCB) traces introduces new challenges for parameter extraction and delay calculation for high-speed system design. PCB traces are dominated by frequency dependent LC propagation which makes precharacterization difficult for all possible configurations. Moreover, simulating the transient behavior of the trace for noise and delay analysis requries the combined used of a variety of models and techniques for efficiently handling lossy, low-loss, frequency dependent, and coupled transmission lines together with lumped elements. In this paper we explain how the frequency dependence caused by ground plane proximity and skin effects can be modeled using the adstracted models. These abstracted (lumped) models are SPICE-compatible and can be simulated in time-domain, along with precharacterized lumped parasitic elements and nonlinear driver and load models.

• International Journal of Aeronautical and Space Sciences
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• v.16 no.1
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• pp.110-122
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• 2015

In this paper, the unsteady aerodynamics and blade structural dynamics of an experimental bearingless rotor were analyzed. Due to the multiple load path and nonlinear behavior of a bearingless rotor, sophisticated structural modeling and structural-aerodynamic coupled analysis is required. To predict the internal load and deformation of an experimental bearingless rotor, trim analysis was implemented. The results showed good agreement when compared with those predicted by CAMRAD II the rotorcraft comprehensive analysis. It is possible to extend the present structural-aerodynamic combined analysis to further advanced configurations of the bearingless rotor in the future.

• Bulletin of the Society of Naval Architects of Korea
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• v.20 no.2
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• pp.21-26
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• 1983

In this light of economical engineering, the optimal configurations of ship structure that can save weights, production costs and operation costs should be investigated. This paper presents the general method of optimization based on non-linear programming and its application to weight and/or cost minimization of ship structure. Oil tanker is chosen as a ship type because of simple layout and easy calculation of stress. With the data of 16,200 DWT oil tanker built by KSEC 1980, this paper shows the procedure mentioned above by means of SUMT combined with two selected search methods. Then the differences between original and redesigned tanker structures are discussed.

• International Journal of High-Rise Buildings
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• v.6 no.2
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• pp.197-205
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• 2017

The conflict between indoor environmental quality and energy consumption has become an unneglectable problem for highrise office buildings, where occupants' productivity is highly affected by their working environment. An effective Façade, therefore, should play the role of an active building skin by adapting to the ever-changing external environment and internal requirements. This paper explores the energy-saving and indoor environment-improving potential of a phase-change material (PCM) integrated Façade. Building performance simulations, combined with parametric study and sensitivity analysis, are adopted in this research. The result quantifies the potential of a PCM-integrated Façade with different configurations and PCM properties, taking as an example a south-oriented typical office room in Shanghai. It is found that a melting temperature of around $22^{\circ}C$ for the PCM layer is optimal. Compared to a conventional Façade, a PCM-integrated Façade effectively reduces total energy use, peak heating/cooling load, and operative temperature fluctuation during the periods of May-July and November-December.

• ETRI Journal
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• v.40 no.5
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• pp.570-581
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• 2018

This work analyzes the performance of implementable detectors for the multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) technique under specific and realistic operation system conditions, including antenna correlation and array configuration. A time-domain channel model was used to evaluate the system performance under realistic communication channel and system scenarios, including different channel correlation, modulation order, and antenna array configurations. Several MIMO-OFDM detectors were analyzed for the purpose of achieving high performance combined with high capacity systems and manageable computational complexity. Numerical Monte Carlo simulations demonstrate the channel selectivity effect, while the impact of the number of antennas, adoption of linear against heuristic-based detection schemes, and the spatial correlation effect under linear and planar antenna arrays are analyzed in the MIMO-OFDM context.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.3169-3174
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• 2008

Future power plants will be required to adopt some type of carbon capture and storage (CCS) technologies to reduce their CO2 emissions. One of distinguished CCS techniques expected to resolve the green house effect is to apply the oxy-fuel combustion technique to power plant, and a lot of research/demonstration programs have been going on in the world. In this paper, CO2-capturing power plants based on gas turbine and oxy-fuel combustion are investigated over several types of configurations. As a prior step, simulation model for 500 MW-class combined cycle power plant was set and was used as a reference case. The efficiencies of several power plants was compared and the advantages and disadvanteges was investigated.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.6
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• pp.556-563
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• 2012

This study focuses on the element configuration of hybrid mounts which are combined with passive elements and active elements. The seven configurations are presented according to connection of an active element to a passive element. The dynamic characteristics and control performance of them are investigated qualitatively using Bode plots. With reference to the transmitted force from internal to external, three cases are selected. In addition, some numerical simulations for the three cases are carried out to confirm the performance quantitatively. Based on this research results, a novel hybrid mount with excellent performance will be able to be developed.

• Journal of Korea Society of Digital Industry and Information Management
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• v.18 no.4
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• pp.41-46
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• 2022

In the fourth industrial era, when various technologies are fused and combined, new and advanced technologies from other industries are used extensively in the maritime industry field. New security threats are also increasing along with the development of new technologies. In addition, in incorporating convergence technologies into the maritime industry, various problems, such as communication definitions and procedures between technologies and customer-customized delays, occur. In this paper, for the problems mentioned above, research results on the network configuration of safer autonomous vessels by supplementing and fusing existing solutions rather than developing new technologies are proposed. In conclusion, the entire network consists of VDI and presents additional configurations to ensure confidentiality, integrity, and availability, which are the three security elements. According to the composition of such a convergence network, it is intended to help prepare countermeasures to protect internal data from external threats.