• 전기학회논문지
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• 제56권11호
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• pp.2033-2035
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• 2007

This paper proposes a novel iterative LMS-based decision feedback equalizer for short burst transmission with relatively short training sequence. In the proposed equalizer, the longer concatenated training sequence can provide the more sufficient channel information and the reused original training sequence can provide the correct decision feedback information. In addition, the overall adaptive processing is performed using the low complexity LMS algorithm. The study shows the performance of the proposed method is enhanced with the number of iterations and, furthermore, better than that of the conventional LMS-based DFEs with the training sequence of longer or equal length. Computational complexity is increased linearly with the number of iterations.

• 한국정보전자통신기술학회논문지
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• 제2권4호
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• pp.45-51
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• 2009

DSP 시스템에서 널리 사용되는 힐버트 변환에서 곱셈 연산은 반드시 필요한 요소이며 변환에 사용되는 계수의 차수가 높아질수록 하드웨어는 복잡하고 많은 양의 게이트를 필요로 한다. 본 연구에서는 힐버트 변환에 사용되는 곱셈연산에 MAG 알고리즘이 적용된 쉬프트와 덧셈을 사용한 곱셈블록을 구현하여 하드웨어의 복잡도를 줄일 수 있다.

• 대한인간공학회지
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• 제32권5호
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• pp.429-435
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• 2013

Objective: This study aims to analyze job satisfaction and accident prevention according to job rotation system types in a motor company. Background: The study of a motor company's job rotation system has come to attention with enhancing productivity, preventing musculoskeletal disorders, and improving quality. Method: In this study, a survey was conducted to show job satisfaction rates according to job rotation systems. Also an investigation was done regarding industrial accidents and previous workers who are receiving treatment for musculoskeletal disorder over the last five years. Results: The job rotation system in this study has been carried out by voluntary decision of workers. Out of the job rotation types, the medium rotation complexity type had high job satisfaction whereas in a high or low rotation complexity type, which many workers prefer, led to less number of accidents and days of sick leave. Application: The results of this study are expected to be a fundamental data to job design.

• Journal of Mechanical Science and Technology
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• 제20권10호
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• pp.1527-1533
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• 2006

Workflow systems have benefited the enterprise and customer in many aspects. But with the increasing complexity of the system, workflow design becomes a complicated and time-consuming process. In this paper, we model the system based on the Hierarchical Colored Petri Nets (HCPN) to avoid the complexity of the system, and the super nets of the model are abstracted as independent components to increase the flexibility, acceptability and maintainability of the system. Another important characteristic of this model is its convenience for reuse and workflow mining. The development process of the overhead traveling crane was given to demonstrate the proposed method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 D
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• pp.2447-2449
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• 2003

In this paper, optimal fuzzy systems using vector quantization and fuzzy logic controllers are designed for vision-based robot control systems. The complexity of the optimal fuzzy system for vision-based control systems is so great that it can not be applied to real vision-based control systems or it can not be useful, because there are so many input-output pairs. Therefore, we generally use the clustering of input-output pairs, in order to reduce the complexity of optimal fuzzy systems. To increase the effectiveness of the clustering, a vector quantization clustering method is proposed. In order to verify the effectiveness of the proposed method experimentally, it is applied to a vision-based arm robot control system.

• 한국통신학회논문지
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• 제22권12호
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• pp.2706-2713
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• 1997

The fast implementation algorithm of M-band discrete wavelet transform is propsed using the factorization of lossless matrix when the length of discrete orthogonal wavelet bases equals to 2M. In computational complexity when direct filtering method is employed, the number of multiplicationand addition is (2M$^{2}$) and (2M$^{2}$ -M), respectively. But by proposed algorithm, it can be reduced to (M$^{2}$+M) and (M$^{2}$+2M-1), respectively. and it is possible to reduce the compuatational complexity further when unitary matrix employed to design the discrete or thogonal wavelet basis has the fast algorithm.

• 대한방사성의약품학회지
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• 제2권1호
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• pp.51-55
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• 2016

Organofluorine compounds have become increasingly important as pharmaceuticals, radiopharmaceuticals, agrochemicals, and material science. Recent advances on the efficient introduction of fluorine to organic molecules are mainly results of development of transition metal catalysts and fluorination reagents. Among the various fluorination reagents, we have been interested in developing more efficient sulfur-based deoxyfluorinating reagents. Here we report various electronic properties of five popular sulfur-based deoxyfluorinating reagents using density functional theory calculation. We believe that the theoretical study on the reagents will assist the rational design of new deoxyfluorinating reagents.

• Asia pacific journal of information systems
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• 제15권3호
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• pp.41-64
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• 2005

The effects of information quality and the importance of information have been reported in the information Systems(IS) literature. However, little has been learned about the impact of data quality(DQ) on decision performance. Recognizing with this problem, this study explores the effects of contextual DQ on decision performance. To examine them, a laboratory experiment was conducted. Based on two levels of contextual DQ and two levels of task complexity, this study had a $2{\times}2$ factorial design. The dependent variables used to measure the outcomes of decision performance were problem-solving accuracy and time. The results demonstrated that the effects of contextual DQ on decision performance were significant. The findings suggest that decision makers can expect to improve their decision performance by enhancing contextual DQ. This research not only extends a body of research examining the effects of factors that can be tied to human decision-making performance, but also provides empirical evidence to validate and extend DeLone and McLean's IS success model.

• 한국IT서비스학회지
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• 제7권4호
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• pp.221-230
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• 2008

Green's relations are five equivalence relations that characterize the elements of a semigroup in terms of the principal ideals. The J relation is one of Green's relations. Although there are known algorithms that can compute Green relations, they are not useful for finding all J relations in the semigroup of all $n{\times}n$ Boolean matrices. Its computation requires multiplication of three Boolean matrices for each of all possible triples of $n{\times}n$ Boolean matrices. The size of the semigroup of all $n{\times}n$ Boolean matrices grows exponentially as n increases. It is easy to see that it involves exponential time complexity. The computation of J relations over the $5{\times}5$ Boolean matrix is left an unsolved problem. The paper shows theorems that can reduce the computation time, discusses an algorithm for efficient J relation computation whose design reflects those theorems and gives its execution results.

• ETRI Journal
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• 제43권2호
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• pp.197-208
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• 2021

Single-carrier frequency division multiple access (SC-FDMA) is currently being used in long-term evolution uplink communications owing to its low peak-to-average power ratio (PAPR). This study proposes a new transceiver design for an SC-FDMA system based on Walsh-Hadamard transform (WHT). The proposed WHT-based SC-FDMA system has low-PAPR and better bit-error rate (BER) performance compared with the conventional SC-FDMA system. The WHT-based SC-FDMA transmitter has the same complexity as that of discrete Fourier transform (DFT)-based transmitter, while the receiver's complexity is higher than that of the DFT-based receiver. The exponential companding technique is used to reduce its PAPR without degrading its BER. Moreover, the performances of different ordered WHT systems have been studied in additive white Gaussian noise and multipath fading environments. The proposed system has been verified experimentally by considering a real-time channel with the help of wireless open-access research platform hardware. The supremacy of the proposed transceiver is demonstrated based on simulated and experimental results.