• ETRI Journal
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• v.32 no.1
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• pp.93-101
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• 2010

A true random number generator (TRNG) is widely used to generate secure random numbers for encryption, digital signatures, authentication, and so on in crypto-systems. Since TRNG is vulnerable to environmental changes, a deterministic function is normally used to reduce bias and improve the statistical properties of the TRNG output. In this paper, we propose a linear corrector for secure TRNG. The performance of a linear corrector is bounded by the minimum distance of the corresponding linear error correcting code. However, we show that it is possible to construct a linear corrector overcoming the minimum distance limitation. The proposed linear corrector shows better performance in terms of removing bias in that it can enlarge the acceptable bias range of the raw TRNG output. Moreover, it is possible to efficiently implement this linear corrector using only XOR gates, which must have a suitable hardware size for embedded security systems.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.511-512
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• 2006

Three stage(CIC-FIR-FIR) decimation filter in delta-sigma A/D converter for audio is designed. A canonical signed digit(CSD) code method is used to minimize area of multipliers. This filter is designed in 0.25um CMOS process and incorporates $1.36\;mm^2$ of active area. Measured results show that this decimation filter is suitable for digital audio A/D converters.

• Journal of the Korean Institute of Navigation
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• v.10 no.2
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• pp.57-81
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• 1986

The conventional school affairs management, with an example of Korea Martitime University (KMU), is studied through the university codes and its internal regulations and the inevitable problems of the conventional school affairs are analyzed. From the view points of complexity of the educational structure and increase in educational population, the computerized school affairs management is increasingly requested. Therefore, in order to design and implement a computerized school affairs management system, a code-system suitable for the KMU is, first of all, constructed and then a data base which copes with various reforms or changes is developed by using the code system and the IMAGE/DMBS of a HP-9040AM computer. A FORTRAN example program shows that the designed data base can be easily transformed into on-line system and made good use of managing school affairs. Furthermore, it is recommended that the university authority organize a research team for designing the total system in future university administration and solving difficult problems occurring through the computerization.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.6
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• pp.1114-1120
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• 2011

Shaped Charge's penetration performance is depended on the shape of warhead and explosive, liner materials. The liner that manufactured to small homogeneous grain increase the penetration performance and decrease the deviation of penetration performance. This texture is obtained by forging process but, creating the process that remove crack and get small homogeneous grain is very hard. In this study, We success to get the homogeneous small grain texture through appling the most suitable process by DEFORM CODE analysis.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.3
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• pp.615-619
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• 2012

Reverse engineering via static analysis is an essential step in software security and it focuses on reconstructing code structures and data abstractions. In particular, reverse engineering of data abstractions is critical to understand software but the previous scheme, VSA, is not suitable for applying to fragmented binaries. This paper proposes an enhanced method through dynamic region assignment.

• Structural Engineering and Mechanics
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• v.50 no.3
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• pp.323-347
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• 2014

This paper proposes a Particle Swarm Optimization (PSO) algorithm, which is improved by making use of the Harmony Search (HS) approach and called HS-PSO algorithm. A computer code is developed for optimal sizing design of non-linear steel frames with various semi-rigid and rigid beam-to-column connections based on the HS-PSO algorithm. The developed code selects suitable sections for beams and columns, from a standard set of steel sections such as American Institute of Steel Construction (AISC) wide-flange W-shapes, such that the minimum total cost, which comprises total member plus connection costs, is obtained. Stress and displacement constraints of AISC-LRFD code together with the size constraints are imposed on the frame in the optimal design procedure. The nonlinear moment-rotation behavior of connections is modeled using the Frye-Morris polynomial model. Moreover, the P-${\Delta}$ effects of beam-column members are taken into account in the non-linear structural analysis. Three benchmark design examples with several types of connections are presented and the results are compared with those of standard PSO and of other researches as well. The comparison shows that the proposed HS-PSO algorithm performs better both than the PSO and the Big Bang-Big Crunch (BB-BC) methods.

• International Journal of Highway Engineering
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• v.16 no.2
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• pp.43-52
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• 2014

PURPOSES : To solve problems in current compaction control DCPT(Dynamic Cone Penetrometer Test), highly correlated with various testing methods, simple, and economic is being applied. However, it、s hard to utilize DCPT results due to the few numerical analyses for DCPT have been performed and the lack of data accumulation. Therefore, this study tried to verify the validation of numerical modeling for DCPT by comparing and analyzing the results of numerical analyses with field tests. METHODS: The ground elastic modulus and PR(Penetration Rate) value were estimated by using PFC(Particle Flow Code) 3D program based on the discrete element method. Those values were compared and analyzed with the result of field tests. Also, back analysis was conducted to describe ground elastic modulus of field tests. RESULTS : Relative errors of PR value between the numerical analyses and field tests were calculated to be comparatively low. Also, the relationship between elastic modulus and PR value turned out to be similar. CONCLUSIONS : Numerical modeling of DCPT is considered to be suitable for describing field tests by carrying out numerical analysis using PFC 3D program.

• Structural Engineering and Mechanics
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• v.49 no.5
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• pp.631-644
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• 2014

Seismic assessment and retrofitting of existing structure is a complicated work that typically requires more sophisticated analyses than performing a new design. Before the implementation of a Code for seismic design of buildings (GBJ 11-89), not enough attention has been paid on seismic performance of structures and a great part of the existing reinforced concrete structures built in China have been poorly designed according to the new version of the same code (GB 50011-2010). This paper presents a case study of seismic assessment of a non-seismically designed reinforced concrete building in China. The structural responses are evaluated using the nonlinear static procedure (the so-called pushover analysis), which requires its introduction within a process that allows the estimation of the demand, against which the capacity is then compared with. The capacity of all structural members can be determined following the design code. Based on the structural performance, suitable retrofitting strategies are selected and implemented to the existing system. The retrofitted structure is analyzed again to check the effectiveness of the rehabilitation. Different types of retrofitting strategy are discussed and classified according to their complexity and benefits. Finally, a proper intervention methodology is utilized to upgrade this typical low-rise non-ductile building.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.113-118
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• 2011

This paper has analyzed recognizing performance depending on the size of iris codes extracting by iris recognition algorithm using scale-space filtering. The iris images were created through pre-processing, the features were extracted by scale-space filtering, and the codes of 16 sizes were generated. The generated code's performance was compared for each code to calculate FAR and FRR by matching method utilizing Hamming distance. Every code had little overlapping portion between same person and other persons group so that the proposed algorithm's superiority was proved, and the performance of iris codes was analyzed for each size focused on convenience to use when implementing in realization. In addition, the iris codes suitable to iris recognition system that is high-reliable and is able to reduce user's inconvenience due to mis-rejection has been presented considering for commercialization.

• Journal of Korea Multimedia Society
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• v.13 no.3
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• pp.359-368
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• 2010

Algorithm visualization is useful for program testing, debugging and evaluating, as well as visual aids in education. When teaching algorithms and data structures, showing exact behaviors by graphics or animation is more suitable than just explaining them. Current systems for algorithm animation are limited to a couple of specific applications and need a special environment. In the proposed system, programmer writes source program in C and animator embeds visualization scripts in the appropriate location of the program. Then user can get an animation code in form of SVG and see a graphical representation on the web browser. Generated SVG animation code is platform independent and can also interact with other XML applications or HTML.