• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.8A
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• pp.725-732
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• 2002

Block-wise MAP (Maximum A posteriori) decoding algorithm for turbo-codes requires less memory than Log-MAP decoding algorithm. The ER (Bit Error Rate) performance of previous block-wise MAP decoding algorithm depend on the block length and training length. To maximize hardware utilization and perform successive decoding, the block length is set to be equal to the training length in previous MAP decoding algorithms. Simulation result on the BER performance shows that the EBR performance can be maintained with shorter blocks when training length is sufficient. This paper proposes an architecture for area efficient block-wise MAP decoder. The proposed architecture employs the decoding schema for reducing memory by using the training length, which in N times larger than block length. To efficiently handle the proposed schema, a pipelined architecture is proposed. Simulation results show that memory usage can be reduced by 30%~45% in the proposed architecture without degrading the BER performance.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.10
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• pp.103-108
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• 2016

With the growing trend of pervasive computing, (the idea that technology is moving beyond personal computers to everyday devices) there is a growing demand for lightweight ciphers to safeguard data in a network that is always available. For all block cipher applications, the AES is the preferred choice. However, devices used in pervasive computing have extremely constraint environment and as such the AES will not be suitable. In this paper we design and implement a new lightweight compact block cipher that takes advantage of both S-P network and the Feistel structure. The cipher uses the S-box of PRESENT algorithm and a key dependent one stage omega permutation network is used as the cipher's P-box. The cipher is implemented on iNEXT-V6 board equipped with virtex-6 FPGA. The design synthesized to 196 slices at 337 MHz maximum clock frequency.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2355-2358
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• 2000

This paper presents signal analyzer design, realization of system parameter estimation, analysis and system parameter estimation of distributed parameter systems using orthogonal function like Walsh function, block pulse function and Haar function.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.2
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• pp.123-130
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• 2016

With the development of fast construction mode in shipbuilding market, the demand on accuracy management of hull is becoming higher and higher in shipbuilding industry. In order to enhance production efficiency and reduce manufacturing cycle time in shipbuilding industry, it is important for shipyards to have the accuracy of ship components evaluated efficiently during the whole manufacturing cycle time. In accurate shipbuilding process, block accuracy is the key part, which has significant meaning in shortening the period of shipbuilding process, decreasing cost and improving the quality of ship. The key of block accuracy control is to create a integrate block accuracy controlling system, which makes great sense in implementing comprehensive accuracy controlling, increasing block accuracy, standardization of proceeding of accuracy controlling, realizing "zero-defect transferring" and advancing non-allowance shipbuilding. Generally, managers of accuracy control measure the vital points at section surface of block by using the heavy total station, which is inconvenient and time-consuming for measurement of vital points. In this paper, a new measurement method based on point clouds technique has been proposed. This method is to measure the 3D coordinates values of vital points at section surface of block by using 3D scanner, and then compare the measured point with design point based on ICP algorithm which has an allowable error check process that makes sure that whether or not the error between design point and measured point is within the margin of error.

• The Journal of Industrial Distribution & Business
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• v.10 no.8
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• pp.33-44
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• 2019

Purpose - As the scope of existing digital transformation expanded to various degrees, the Fourth Industrial Revolution came into being. In 2016, Klaus Schwab, Chairman of the World Economic Forum (WEF), said that the new technologies that lead the fourth industrial revolution are AI, Block chain, IoT, Big Data, Augmented Reality, and Virtual Reality. This technology is expected to be a full-fledged fusion of digital, biological and physical boundaries. Everything in the world is connected to the online network, and the trend of 'block chain' technology is getting attention because it is a core technology for realizing a super connective society. If the block chain is commercialized at the World Knowledge Forum (WKF), it will be a platform that can be applied to the entire industry. The block chain is rapidly evolving around the financial sector, and the impact of block chains on logistics, medical services, and public services has increased beyond the financial sector. Research design, data, and methodology - Figure analysis of data and social science analytical software of IBM SPSS AMOS 23.0 and IBM Statistics 23.0 were used for all the data researched. Data were collected from hotel employees in China from 25th March to 10th May. Results - The purpose of this study is to investigate the effect of the block chain characteristics of the existing hotel reservation system on the intention to use and to examine the influence of the block chain characteristics of the hotel reservation system on the intention to use, We rearranged the variables having the same or similar meaning and analyzed the effect of these factors on the intention to use the block chain characteristic of the hotel reservation system. 339 questionnaires were used for analysis. Conclusions - There are only sample hotel workers in this study, and their ages are in their 20s and 30s. In future studies, samples should be constructed in various layers and studied. In this study, the block chain characteristics are set as five variables as security, reliability, economical efficiency, availability, and diversity. Among them, Security and reliability made positive effects on the perceived usefulness. Also, security and economics did on the perceived ease. Availability and diversity did on both perceived usefulness and perceived ease. Perceived ease did on perceived usefulness. And perceived ease and perceived usefulness did on user intent. But security and economics did not on the perceived usefulness

• Journal of the Korea Institute of Information Security & Cryptology
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• v.11 no.1
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• pp.13-23
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• 2001

This paper implemented into hardware SEED which is the KOREA standard 128-bit block cipher. First, at the respect of hardware implementation, we compared and analyzed SEED with AES finalist algorithms - MARS, RC6, RIJNDAEL, SERPENT, TWOFISH, which are secret key block encryption algorithms. The encryption of SEED is faster than MARS, RC6, TWOFISH, but is as five times slow as RIJNDAEL which is the fastest. We propose a SEED hardware architecture which improves the encryption speed. We divided one round into three parts, J1 function block, J2 function block J3 function block including key mixing block, because SEED repeatedly executes the same operation 16 times, then we pipelined one round into three parts, J1 function block, J2 function block, J3 function block including key mixing block, because SEED repeatedly executes the same operation 16 times, then we pipelined it to make it more faster. G-function is implemented more easily by xoring four extended 4 byte SS-boxes. We tested it using ALTERA FPGA with Verilog HDL. If the design is synthesized with 0.5 um Samsung standard cell library, encryption of ECB and decryption of ECB, CBC, CFB, which can be pipelined would take 50 clock cycles to encrypt 384-bit plaintext, and hence we have 745.6 Mbps assuming 97.1 MHz clock frequency. Encryption of CBC, OFB, CFB and decryption of OFB, which cannot be pipelined have 258.9 Mbps under same condition.

• Journal of the Korean housing association
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• v.14 no.2
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• pp.77-88
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• 2003

The access area, so called "core" in the housing block, makes a buffer zone between public open space and private interior space, as well as offers chances of communication for the users. Planning and design of this area, however, tend to be not attended, comparing with another spaces in the multifamily housing block. This paper is aimed at investigating examplary model European cases and, thus, finding out some positive and applicable planning skills for multifamily housing in Korea. This study covers following aspects; firstly, the important social meaning of core area was analyzed in comparison of Korea and Europe, secondly, intensive studies on the spots, visiting German, Austrian and Dutch cases, made it possible to grasp the prevailling tendency toward assessment of this area in the Continent, Thirdly, useful planning elements and skills by European examples for more user friendliness, more economization and raising the quality of spatial design and sequential experience were founded out with regard to various core types. and lastly, some concrete guidelines for planning are presented for the improvement of so far monotnousely designed core area in the local multifamily housing. Consequently those European cases made it clear that the planning of core area is closely related to the total design of housing blocks. This study maybe conducive not only to the planning of this area, but also further to the increase of the quality of life in multifamily housing.y housing.

• International Journal of Aeronautical and Space Sciences
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• v.1 no.1
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• pp.13-20
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• 2000

The applications of CFD in the design process of a transonic civil transport at Korea Aerospace Research Institute (KARI) are outlined. Three Navier-Stokes solvers, developed at KARI with different grid approaches, are used to predict the aerodynamic coefficients and solve the flowfield of various configurations. Multi-block, Chimera, and unstructured grids are the approaches implemented. The accuracy of the codes is verified for the transonic flow about RAE wing/fuselage configuration. The multi-block code is used to provide the detailed data on the flowfield around a wall interference model with different test section sizes which will be used in establishing the wall interference correction method. The subsonic and transonic flowfields about K100-04A, one of the configurations of a 100-seater transport developed by KARI and Korea Commercial Aircraft Development Consortium (KCDC), are computed to predict the aerodynamic coefficients. The results for the subsonic flow are compared with those of wind tunnel test, and the agreement is found to be excellent. The interference effect of nacelle installation on the wing of K100-04A is also investigated using the unstructured grid method, and about 10% reduction in wing lift is observed. The accuracy of the three developed codes is verified, and they are used as an efficient tool in the design process of a transonic transport.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.12
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• pp.3071-3095
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• 2013

Configuring optimization of wireless sensor networks, which can improve the network performance such as utilization efficiency and network lifetime with minimal energy, has received considerable attention in recent years. In this paper, a cross layer optimal approach is proposed for multi-source linear network and grid network under Rayleigh block-fading channels, which not only achieves an optimal utility but also guarantees the end-to-end reliability. Specifically, in this paper, we first strictly present the optimization method for optimal nodal number $N^*$, nodal placement $d^*$ and nodal transmission structure $p^*$ under constraints of minimum total energy consumption and minimum unit data transmitting energy consumption. Then, based on the facts that nodal energy consumption is higher for those nodes near the sink and those nodes far from the sink may have remaining energy, a cross layer optimal design is proposed to achieve balanced network energy consumption. The design adopts lower reliability requirement and shorter transmission distance for nodes near the sink, and adopts higher reliability requirement and farther transmission distance for nodes far from the sink, the solvability conditions is given as well. In the end, both the theoretical analysis and experimental results for performance evaluation show that the optimal design indeed can improve the network lifetime by 20-50%, network utility by 20% and guarantee desire level of reliability.

• Broadcasting and Media Magazine
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• v.11 no.1
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• pp.68-77
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• 2006

The Cognitive Radio (CR) technology is a promising solution for exploiting the limited spectrum resources and providing flexibility of spectrum usage. Future interactive broadcasting service can be realized by utilizing CR concept, since the up-link return channel can be found by the spectrum sensing method, which is core functional block of the CR system. In this paper, the spectrum sensing technologies of CR system is presented. First the system architecture of the CR with spectrum sensing block is presented. The suggested spectrum sensing technique consists of the coarse and the fine spectrum sensing. The coarse spectrum sensing technique adopted the wavelet transform to provide the multi-resolution sensing feature - Multi-Resolution Spectrum Sensing (MRSS). The fine spectrum sensing technique uses the beneficial properties of the autocorrelation function Analog Auto-Correlation (AAC). The simulation results for the proposed sensing technologies are presented for various incumbent signals.