• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.825-832
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• 2008

A simulation program is developed for analysing thermal networking process between the District heating and the CES(Community Energy Supply) systems. The effects of thermal networking on the District heating facilities previously being operated are implemented using mathematical correlations in terms of the fuel consumption and energy load such as heating and electricity. The operational characteristics according to the prime movers is modeled based on the materials of efficiency as a function of operational load. The unit energy load model is also developed extensively for several building types such as apartment complex, hotel, hospital, buildings for business and commercial use respectively. The specific features of the newly developed program in simulation of thermal networking process in district heating is described in terms of the reliability and the easiness for operating it etc.

• Journal of Ocean Engineering and Technology
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• v.20 no.4 s.71
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• pp.24-30
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• 2006

Different methods exist for the estimation of thermaldeformation of plates in the line heating process. These are based on the assumption of residual strains in the heat-affected zone, known as the method of inherent strains, or simulated relations between heating conditions and residual deformations. The purpose of this paper is to develop a simulator of thermal deformation in the line heating, using the artificial neural network. Curvature deformations for the plate-forming are investigated, which can be used as a prime deformation parameter in the process. The curvature of plates are calculated using the approximation of plate surface by NURBS. Line heating experiments for 11 specimens of different thickness and heating conditions were performed. Two neural networks predicting the maximum temperature and curvature deformations at the heating line are studied. It was concluded that the thermal deformations predicted by the neural network can be used in a line heating simulator, which is considered an attractive and practical alternative to the existing methods.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.1
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• pp.60-69
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• 2014

Footstep detection using seismic sensors for security is a very meaningful task, but readings can easily fluctuate due to noise in outdoor environment. We propose NSSC method based on nonlinear spectral subtraction and cross-correlation using prime footstep model signal as a footstep signal refining process that enhances the signal-to-noise ratio (SNR) and attenuates noise. After de-noising, a detection event classification method is presented as further refining process to ensure that the detection result is a footstep. To validate the proposed algorithm, representative experiments including sunny and rainy-day cases are demonstrated.

• Smart Structures and Systems
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• v.7 no.4
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• pp.289-302
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• 2011

In marine clay deposits, naturally formed or artificially reclaimed, the evaluation and monitoring of the consolidation process has been a critical issue in civil engineering practices due to the time frame required for completing the consolidation process, which range from several days to several years. While complementing the conventional iconographic method suggested by Casagrande and recently developed in-situ techniques that measure the shear wave, this study suggests an alternative experimental procedure that can be used to evaluate the consolidation state of marine clay deposits using the shear wave velocity. A laboratory consolidation testing apparatus was implemented with bimorph-type piezoelectric bender elements to determine the effective stress-shear wave velocity (${\sigma}^{\prime}-V_s$) relationship with the marine clays of interest. The in-situ consolidation state was then evaluated by comparing the in-situ shear wave velocity data with the effective stress-shear wave velocity relationships obtained from laboratory experiments. The suggested methodology was applied and verified at three different sites in South Korea, i.e., a foreshore site in Incheon, a submarine deposit in Busan, and an estuary delta deposit in Busan. It is found that the shear wave-based experimental procedure presented in this paper can be effectively and reliably used to evaluate the consolidation state of marine clay deposits.

• Transactions of the Society of Information Storage Systems
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• v.3 no.3
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• pp.149-153
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• 2007

Perpendicular patterned magnetic media have been regarded as a prime candidate to achieve an ultra-high magnetic recording density of over 1 Tera-bits/$inch^2$. Patterned magnetic media with nanoscale patterns have been fabricated using various nanopatterning technologies. We focused on the two technical issues of nanoinjection molding technology. Firstly, we have investigated a cost-effective method to fabricate metallic stamps. Secondly, we focused on the analysis of nanoinjection molding with passive heating, where the replication of 50 nm nanopillar arrays was successful. The effect of the thermal insulation layer on the replication quality was examined by analytical and experimental methods. Finally, we deposited a magnetic layer on a injection molded nanopillars and measured. Our methodology can provide cost-effective mass-production for patterned magnetic media.

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.47-50
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• 2004

In this paper, we implement an Elliptic Curve Cryptosystem(ECC) processor for DTCP. Because DTCP(Digital Transmission Content Protection) uses GF(p), where p is a 160-bit prime integer, we design a scalar multiplier based on GF(p). The scalar multiplier consists of a modular multiplier and an adder. The multiplier uses montgomery algorithm which is implemented with CSA(Carry-save Adder) and CLA(Carry-lookahead Adder). Our new scalar multiplier has been synthesized using Samsung 0.18 um CMOS technology and the maximum operation frequency is estimated 98 MHz, with the size about 65,000 gates. The resulting performance is 29.6 kbps, that is, it takes 5.4 msec to process a 160-bit data frame. We assure that this performance is enough to be used for digital signature, encryption/decryption, and key exchanges in real time environments.

• Journal of information and communication convergence engineering
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• v.12 no.3
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• pp.145-153
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• 2014

The improvements of embedded processors make future technologies including wireless sensor network and internet of things feasible. These applications firstly gather information from target field through wireless network. However, this networking process is highly vulnerable to malicious attacks including eavesdropping and forgery. In order to ensure secure and robust networking, information should be kept in secret with cryptography. Well known approach is public key cryptography and this algorithm consists of finite field arithmetic. There are many works considering high speed finite field arithmetic. One of the famous approach is Montgomery multiplication. In this study, we investigated Montgomery multiplication for public key cryptography on embedded microprocessors. This paper includes helpful information on Montgomery multiplication implementation methods and techniques for various target devices including 8-bit and 16-bit microprocessors. Further, we expect that the results reported in this paper will become part of a reference book for advanced Montgomery multiplication methods for future researchers.

• Korean Institute of Interior Design Journal
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• v.17 no.1
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• pp.93-101
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• 2008

One of the big difference between Aalto and other modem architects lies in an attitude that Aalto went beyond the principle of dogmatic functionalism. As an architect of Northern Europe, Aalto made unique architecture that showed both the language of modem architecture and vernacular architecture. He presented the best example which showed modernity in architecture without losing the meaning of the context including site, region and cultural tradition. With this background, Aalto developed his own typological design approach. As Wolfsburg church was designed in his prime of time, it showed the origin and evolutionary process of religious architecture as well as general features of Aalto's design. Clustered site plan, dynamic space of interior, the adequate control of natural light are representative characteristics found in Aalto's religious architecture. Wolfsburg church also demonstrate these features in more specific way including the continuity of wall and ceiling that showed spatial dynamics, free opening of wall which reflects on functions, and careful adjust of natural light. As a result, Aalto showed his typological design strategy that added new design ideas to the accumulated design vocabularies in the design of Wolfsburg church.

• Journal of the Korean Society for Heat Treatment
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• v.18 no.5
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• pp.297-304
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• 2005

This study was performed to determine the repair weldability of the damaged Ni type superalloy used for gas turbine blade. The experimental works included the evaluation of the microstructures of the damaged blade, selection of the repair welding procedure, characterization of repair weldment and finding the heat treatment procedures for repaired weldment. The morphology of the microstructure for the base metal was composed of austenite matrix with cubical ${\gamma}^{\prime}$ phase, MC type coarse precipitates located within grain and fine $M_{23}C_6$ type precipitates decorated at grain boundaries. The repair welding process using 90 amp current exhibited the best weld properties showing no weld microcracks. The solution and aging heat treatments of the repaired weldment could recover the original service properties of the damaged blade.

• Journal of the Korean Society for Heat Treatment
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• v.26 no.4
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• pp.185-190
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• 2013

Influence of solution treatment (T4) and peak-aging (T6) on damping capacity was investigated in permanent-mold cast Mg-3%Nd alloy. In as-cast state, the microstructure was characterized by eutectic $Mg_{12}Nd$ intermetallic phase network in the intergranular region. T4 treatment resulted in a dissolution of the eutectic particles, but small amount of the particles still remained in the microstructure. After T6 treatment, nano-sized ${\beta}^{\prime}(Mg_{12}Nd)$ particles were precipitated within the matrix. T4 microstructure showed higher damping capacity than as-cast and T6 ones. In view of the microstructural features, this may well be associated with the dissolution of second-phase particles which play a role in pinning the dislocations acting as a damping source.