• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.227-230
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• 2002

In this paper, we propose an algorithm to decode Data Matrix two dimensional barcode symbology. We employ hough transform and bilinear image warping to extract the barcode region from the image scanned using a CMOS digital camera. The location of barcode can be found by applying Hough transform. However, barcode image should be warped due to the nonlinearity of lens and the viewing angle of camera. In this paper, bilinear warping transform is adopted to wa게 and align the barcode region of the scanned image. Codeword can be detected from the aligned barcode region.

• Information and Communications Magazine
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• v.32 no.8
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• pp.76-82
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• 2015

본 고에서는 그래프 상태(graph state)를 이용하여 양 자 오류 정정 부호를 설계하는 기법에 대해서 알아본다. 그래프 상태는 꼭짓점과 각 꼭짓점을 연결하는 변으로 구성된다. 그래프 상태에서 각 꼭지점은 실제 코드워드의 각 큐비트에 해당하며 꼭지 점을 연결하는 변은 양자 오류 정정 부호의 부호화 방식을 결정한다. 본 고에서는 그래프 상태의 특성을 알아보고 그래프 상태 기반 양자 오류 정정 부호 설계 기법을 이용하여 단일 오류를 검출할 수 있는 6-큐비트 양자 오류 정정 부호 설계 방법에 대해 알아본다.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11b
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• pp.1575-1578
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• 2002

본 논문에서는 공간-시간 블록 부호디자인(Space-Time Block Code) 관점에서 직교-디자인(Orthogonal-design) 즉, 최소거리가 5이면서 완전-계수(Full-Rank)인 디자인을 비교대상으로 완전-계수(Full-Rank)가 아니면서 최소거리가 5와7인 두 부호에 관하여 연구되어졌다.

• The Journal of the Korea Contents Association
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• v.17 no.6
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• pp.32-38
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• 2017

Despite the opinion that certificate is useless, half of the population in Korea (approx. 35 million) get an certificate, and use it for internet banking, internet shopping, stock trading, and so on. Most users store their certificates on a usb memory or smartphone, and certificates or passwords stored on such storage media can be easily attacked and used to disguise as legitimate users. Due to these security problem of certificate, a various authentication technologies has been proposed such as smartphone owner authentication using SMS, and a personal authentication using biometric authentication. However, a safe technique is not presented yet without user password, and certificate. In this paper, I proposed a method to secure certificate/private key without a user password using a combination of USIM card and smartphone's information. Even if a hacker gets the user password, the certificate, and the private key, he can not use the certificate. User do not need to remember complex password which is a combination of alphabetic / numeric / special characters, and use his certificate safely.

• Information and Communications Magazine
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• v.32 no.10
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• pp.41-47
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• 2015

본고에서는 해밍(Hamming) 부호화된 미지의 신호를 바탕으로 전송된 채널 코딩의 종류에 대해서 알아낼 수 있는 알고리즘을 제안한다. 우선 해밍 코드의 부호화, 복호화 과정을 설명한다. (n,k) 해밍 코드의 부호화 과정을 위하여 사용되는 제너레이터 행렬 G는 (k * n)의 크기를 갖게 되며 복호화 과정을 위하여 사용되는 패리티 체크 행렬 H는 (n-k * n)의 크기를 갖게 된다. 그리고 설계한 알고리즘의 동작원리를 수신 신호의 상태에 따라 설명한다. 수신 신호의 앞에 프리앰블이 있는 경우나 수신신호가 Inverse 또는 Reverse 되어 있는 등 여러 경우에 대비한 알고리즘 설계 방법을 알아본다. 이렇게 설계한 알고리즘은 복잡도가 낮고 확장이 용이하며 수신 신호의 코드워드의 시작점을 쉽게 알 수 있는 장점을 가지고 있어 일반 사용자의 통신 시스템 뿐만 아니라 군사용 통신 체계에 적용하기에도 적합하다.

• Journal of KIISE:Information Networking
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• v.32 no.4
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• pp.543-550
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• 2005

Demand for better services in the Internet has been increasing due to the rapid growth of the Internet, and hence next generation routers are required to perform intelligent packet classification. For a given classifier defining packet attributes or contents, packet classification is the process of identifying the highest priority rule to which a packet conforms. A notable characteristic of real classifiers is that a packet matches only a small number of distinct source-destination prefix pairs. Therefore, a lot of schemes have been proposed to filter rules based on source and destination prefix pairs. However, most of the schemes are based on sequential one-dimensional searches using trio which requires huge memory. In this paper, we proposea memory-efficient two-dimensional search scheme using source and destination prefix pairs. By constructing binary prefix tree, source prefix search and destination prefix search are simultaneously performed in a binary tree. Moreover, the proposed two-dimensional binary prefix tree does not include any empty internal nodes, and hence memory waste of previous trio-based structures is completely eliminated.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.11
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• pp.9-17
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• 2011

As semiconductor process rapidly developed, the density of chips becomes higher and the space between adjacent lines narrows smaller. This trend increases the capacitance and inductance in interconnects and the coupling-capacitance of adjacent lines grows even bigger than the self-capacitance of themselves, especially in global interconnects. Inductive and capacitive coupling observed in these phenomena may cause serious problems in signal integrity. This paper proposes a codeword generation technique using extra interconnect lines to reduce the crosstalk caused by inductive and capacitive coupling and to reduce dynamic power consumption considering probability of input data. To estimate the performance of the proposed technique, the experimental results have been obtained using FastCap, FastHenry and HSPICE, and it has been shown that the power consumption using the proposed technique has yielded approximately 15% less than the results of the previous technique.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.11
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• pp.9-14
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• 2016

In the holographic data storage system, the data can be stored more than one bit per pixel and the storage capacity and transmission rate can be increased. In this paper, we proposed a sparse-ON pixel 4/6 balanced-modulation code that the code rate is 1.33 (bit/pixel) with uniform page density. Even though the performance of the proposed sparse-ON pixel 4/6 balanced-code is similar to 2/3 and 6/9 modulation codes, it can increase the storage capacity more than these modulation codes and also store more pages in a volume by reducing the rate of ON pixels to mitigate IPI (inter-page interference).

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.4
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• pp.34-43
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• 2010

Texture information plays an important role in object recognition and classification. To perform an accurate classification, the texture feature used in the classification must be highly discriminative. This paper presents a novel texture descriptor for texture-based image retrieval and its application in Computer-Aided Diagnosis (CAD) system for Emphysema classification. The texture descriptor is based on the combination of local surrounding neighborhood difference and centralized neighborhood difference and is named as Combined Neighborhood Difference (CND). The local differences of surrounding neighborhood difference and centralized neighborhood difference between pixels are compared and converted into binary codewords. Then binomial factor is assigned to the codewords in order to convert them into high discriminative unique values. The distribution of these unique values is computed and used as the texture feature vectors. The texture classification accuracies using Outex and Brodatz dataset show that CND achieves an average of 92.5%, whereas LBP, LND and Gabor filter achieve 89.3%, 90.7% and 83.6%, respectively. The implementations of CND in the computer-aided diagnosis of Emphysema is also presented in this paper.

• Journal of Digital Convergence
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• v.12 no.2
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• pp.285-293
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• 2014

Two-dimensional PDF417 bar code has a wide range of use and has a storage capacity to compress a large amount of data. With these characteristics, PDF417 has been used in various ways to prevent the forgery and alteration of important information in documents. On the other hand, previous decoding methods in PDF417 barcode are slow and inefficient because they simply employ the standard specifications of AIM (Association for Automatic Identification and Mobility). Therefore, this paper propose an efficient and fast algorithm of decoding PDF417 bar code. As a result, the proposed decoding algorithm will be more faster and efficient than previous methods.