• Journal of Electrical Engineering and Technology
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• 제6권3호
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• pp.418-422
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• 2011

For low-power sensor networks, a compact design of advanced encryption standard (AES) algorithm is needed. A very small AES core for ZigBee devices that accelerates computation in AES algorithms is proposed in this paper. The proposed AES core requires only one S-Box, which plays a major role in the optimization. It consumes less power than other block-wide and folded architectures because it uses fewer logic gates. The results show that the proposed design significantly decreases power dissipation; however, the resulting increased clock cycles for 128-bit block data processing are reasonable for IEEE 802.15.4 standard throughputs.

• Journal of applied mathematics & informatics
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• 제6권3호
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• pp.901-914
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• 1999

In [6] Schensted constructed the Schensted algorithm giving a bijection between permutations and pairs of Young standard tableaux. After knuth generalized it to column strict tableaux in [3] various analogs of the Schensted algorithm came. In this paper we describe the bumping algorithm on the shifted rim hook tableaux which is the basic building block of the Schensted algorithm for shifted rim book tableaux.

• 한국정보통신학회논문지
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• 제21권4호
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• pp.731-736
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• 2017

본 논문에서는 능동형 RFID 시스템의 표준인 ISO/IEC 18000-7의 성능을 개선하기 위하여 간소화된 태그 수집 알고리즘을 제안한다. 제안한 알고리즘에서는 태그 수집 라운드의 시작을 나타내는 수집 명령을 수정하여, 이전 라운드의 LP 구간 응답에 대한 결과를 포함시킨다. 수집 명령을 수신한 태그는 자신이 응답한 슬롯의 충돌 여부를 확인하고, 별도의 점대점 읽기 명령과 슬립 명령 없이 자신의 데이터 슬롯으로 추가적인 데이터를 전송하고 슬립 상태로 천이한다. 표준에서의 수집 라운드는 일련의 수집 명령, 수집 응답, 읽기 명령, 읽기 응답, 및 슬립 명령으로 구성된다. 반면, 제안한 태그 수집 알고리즘은 표준과는 달리 하나의 수집 라운드가 수집 명령 및 수집 응답으로만 구성된다. 성능 분석결과, 태그의 수가 300개일 때 제안한 기법의 평균 식별지연은 표준에 비하여 16% 개선됨을 알 수 있었다.

• 한국통신학회논문지
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• 제27권8B호
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• pp.809-818
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• 2002

본 논문에서는 3GPP 표준인 WCDMA 시스템에 호환성을 유지하면서 적용될 수 있는 새로운 셀 탐색 알고리즘을 제안한다. 기존 WCDMA 시스템에서는 2개의 동기 채널(P-SCH 및 S-SCH)을 이용하여 셀 탐색을 수행하는데 반해 제안하는 셀 탐색 알고리즘은 하나의 동기 채널만을 이용하여 슬롯 동기와 프레임 동기 그리고 코드 그룹 아이디를 획득할 수 있다. 이를 위하여 제안하는 알고리즘에서는 기존 WCDMA의 P-SCH에 극성 코드를 이용한 극성 변조를 수행함으로써 스크램블링 코드의 그룹핑 정보를 전송한다. 제안하는 셀 탐색 알고리즘은 기존 WCDMA 셀 탐색 알고리즘에 비해 하나의 동기 채널만을 이용하기 때문에 기지국에서 송신 신호의 이득을 얻을 수 있으며 동시에 수신기의 복잡도를 줄일 수 있는 특징을 갖는다. 제안하는 알고리즘은 특히 SNR 좋지 못한 채널 환경에서 기존 셀 탐색 알고리즘에 비하여 셀 탐색 시간면에서 우수한 성능을 보임을 시뮬레이션을 통하여 검증하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권8호
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• pp.2881-2894
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• 2014

In complicated environment, context information plays an important role in image segmentation/labeling. The recently proposed auto-context algorithm is one of the effective context-based methods. However, the standard auto-context approach samples the context locations utilizing a fixed radius sequence, which is sensitive to large scale-change of objects. In this paper, we present a scale invariant auto-context (SIAC) algorithm which is an improved version of the auto-context algorithm. In order to achieve scale-invariance, we try to approximate the optimal scale for the image in an iterative way and adopt the corresponding optimal radius sequence for context location sampling, both in training and testing. In each iteration of the proposed SIAC algorithm, we use the current classification map to estimate the image scale, and the corresponding radius sequence is then used for choosing context locations. The algorithm iteratively updates the classification maps, as well as the image scales, until convergence. We demonstrate the SIAC algorithm on several image segmentation/labeling tasks. The results demonstrate improvement over the standard auto-context algorithm when large scale-change of objects exists.

• 전기학회논문지
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• 제57권5호
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• pp.902-907
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• 2008

Shape of the pulse waveform is affected by the visco-elasticity characteristics of the arterial wall and the reflection waves generated at the bifurcations of arterial branches. This study was designed to improve the accuracy for the extraction of pulse wave features, then proved the superiority of the developed algorithm by clinical evaluation. Upstroke point of the pulse wave was used as an extraction feature since it is minimally affected by the waveform variation. R-peak of the ECG was used as a reference to decide the minimum level, then intersection of the least squares of regression line was used as an upstroke point. Developed algorithm was compared with the existing minimum value detection algorithm and tangent-intersection algorithm using data obtained from 102 subjects. Developed algorithm showed the least standard deviation of $0.29{\sim}0.44\;m/s$ compared with that of the existing algorithms, $0.91{\sim}3.66\;m/s$. Moreover, the rate of standard deviation of more than 1.00m/s for the PWV values reduced with the range of $29.0{\sim}42.4%$, which proved the superiority of the newly developed algorithm.

• 한국정보통신학회논문지
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• 제13권12호
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• pp.2541-2546
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• 2009

EPCglobal Class-1 Gen-2 충돌방지 기법에서는 Q-알고리즘을 통하여 질의 라운드의 프레임 크기를 결정한다. Q-알고리즘은 리더의 식별영역 내에 있는 태그의 수를 추정하지 않고 슬롯의 상태만을 이용하여 질의 라운드의 프레임 크기를 계산하므로 다른 DFSA 알고리즘에 비하여 리더의 알고리즘이 단순한 장점이 있다. 반면, Q-알고리즘에서는 프레임 크기를 조절하기 위한 매개변수의 최적화 된 값은 정의하지 않고 있다. 따라서 본 논문에서는 시뮬레이션을 통하여 최소의 식별시간을 얻을 수 있는 최적의 매개변수 값을 제안하였다.

• Journal of information and communication convergence engineering
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• 제9권2호
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• pp.172-176
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• 2011

In the Gen-2 Q-algorithm, the values of weight C, which is the parameter for incrementing or decrementing the slot-count size, are not optimized in the standard. However, the standard suggests that the reader uses small values of C when the slot-count is large and larger values of C when the slot-count is small. In this case, if the reader selects an inappropriate weight, there are a lot of empty or collided slots. As a result, the performance will be declined because the frame size does not converge to the optimal point quickly during the query round. In this paper, we propose a scheme to select the weight based on the slot-count size of current query round. Through various computer simulations, it is demonstrated that the proposed scheme achieves more stable performances than Gen-2 Q-algorithm.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제6권2호
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• pp.138-143
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• 2006

In this paper, we have presented a Sequential Agglomerative Hierarchical Nested (SAHN) algorithm-based data clustering method in fuzzy inference system to achieve optimal performance of fuzzy model. SAHN-based algorithm is used to give possible range of number of clusters with cluster centers for the system identification. The axes of membership functions of this fuzzy model are optimized by using cluster centers obtained from clustering method and the consequence parameters of the fuzzy model are identified by standard least square method. Finally, in this paper, we have observed our model's output performance using the Box and Jenkins's gas furnace data and Sugeno's non-linear process data.

• 대한전기학회논문지:시스템및제어부문D
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• 제53권10호
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• pp.720-726
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• 2004

The data transmission over MVB(Multifunction Vehicle Bus) of TCN(Train Communication Network) is divided into the periodic transmission phase and the sporadic transmission phase. TCN standard recommends the event-polling method as the message transfer in the sporadic phase. However, since the event-polling method does not use pre-scheduling to the priority of the messages, it is inefficient for the real-time systems. To schedule message transmission, a master node should know the priority of message to be transmitted by a slave node prior to the sporadic phase, but the existing TCN standard does not support any protocol for this. This paper proposes the slave frame bit-stuffing algorithm, with which a master node gets the necessary information for scheduling and includes the simulation results of the event-polling method and the proposed algorithm.