• Journal of applied mathematics & informatics
• /
• v.28 no.1_2
• /
• pp.209-216
• /
• 2010

A spectrally arbitrary complex sign pattern A is a complex sign pattern of order n such that for every monic nth degree polynomial f(x) with coefficients from $\mathbb{C}$, there is a matrix in the qualitative class of A having the characteristic polynomial f(x). In this paper, we show a necessary condition for a spectrally arbitrary complex sign pattern and introduce a minimal spectrally arbitrary complex sign pattern $A_n$ all of whose superpatterns are also spectrally arbitrary for $n\;{\geq}\;2$. Furthermore, we study the minimum number of nonzero parts in a spectrally arbitrary complex sign pattern.

• Journal of Trauma and Injury
• /
• v.20 no.2
• /
• pp.144-148
• /
• 2007

Purpose: The management of hemorrhagic shock is critical for trauma patients. To assess hemorrhagic shock, the clinician commonly uses a change in positional blood pressure, the shock index, an estimate of the diameter of inferior vena cava based on sonography, and an evaluation of hypoperfusion complex shown on a CT scan. To add the finding for the hypoperfusion complex, the 'halo sign' was introduced recently. To our knowledge, this 'halo sign' has not been evaluated for its clinical usefulness, so we designed this study to evaluate its usefulness and to find the useful CT signs for hypoperfusion complex. Methods: The study was done from January 2007 to May 2007. All medical records and CT images of 124 patients with trauma were reviewed, of which 103 patients were included. Exclusion criteria was as follows: 1) age < 15 year old and 2) head trauma score of AIS ${\geq}$ 5. Results: The value of kappa, to assess the inter-observer agreement, was 0.51 (p < 0.001). The variables of the halo-sign-positive group were statistically different from those of the halo-sign-negative group. The rate of transfusion for the halo-sign-positive group was about 10 times higher than that of the halo-sign-negative group and the rate of mortality was about 6 times higher. Conclusion: In the setting of trauma, early abdominal CT can show diffuse abnormalities due to hypoperfusion complex. Recognition of these signs is important in order to prevent an unwanted outcome in hemorrhagic shock. We conclude that the halo sign is a useful one for hypoperfusion complex and that it is useful for assessing the degree of hemorrhagic shock.

• Proceedings of the Korea Society of Design Studies Conference
• /
• 2005.05a
• /
• pp.116-117
• /
• 2005

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.47 no.9
• /
• pp.37-43
• /
• 2010

An Interference Cancellation Wireless Repeater transmitts directly amplified the RF signal input to extend the coverage of the base station. Such a repeater inevitably suffers from the feedback interferences due to the environment and the adaptive Interference Cancelling System(ICS) is necessary. In this paper, the Variable Stepsize Complex Sign -Sign(VSCSS) LMS algorithm for ICS is presented. The algorithm can be implemented without multiplication/division arithmetic operation so that the required logic resources can be dramatically reduced in FPGA implementation. The performance of the proposed algorithm was analyzed in comparison with CSS-LMS algorithm and the learning curves obtained from simulation showed an excellent agreement with the theorical prediction. The simulation result with ICS in fading feedback channel environment showed the performance of the proposed algorithm is competible with NLMS algorithm.

• The Journal of the Korea Contents Association
• /
• v.5 no.4
• /
• pp.85-93
• /
• 2005

In this paper, we propose recognition system which tracks the unmarked hand of a person performing sign language in complex background. First of all, we measure entropy for the difference image between continuous frames. Using a color information that is similar to a skin color in candidate region which has high value, we extract hand region only from background image. On the extracted hand region, we detect a contour and recognize sign language by applying improved centroidal profile method. In the experimental results for 6 kinds of sing language movement, unlike existing methods, we can stably recognize sign language in complex background and illumination changes without marker. Also, it shows the recognition rate with more than 95% for person and $90\sim100%$ for each movement at 15 frames/second.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.14 no.3
• /
• pp.133-142
• /
• 2019

The existing auxiliary communicating aids for the hearing-impaired have an inconvenience of using additional expensive sensing devices. This paper presents a hand image detection based algorithm to interpret the sign language of the hearing-impaired. The proposed sign language recognition system exploits the hand image only captured by the camera without using any additional gloves with extra sensors. Based on the hand image processing, the system can perfectly classify several numeric sign language representations. This work proposes a simple lightweight classification algorithm to identify the hand image of the hearing-impaired to communicate with others even further in an environment of complex background. Experimental results show that the proposed system can interpret the numeric sign language quite well with an accuracy of 95.6% on average.

• Journal of the Ergonomics Society of Korea
• /
• v.26 no.4
• /
• pp.143-146
• /
• 2007

Due to the expansion of cities and the increasing number of large-scale and complex public spaces, there is an increase in public signage. Moreover, the information described on these signs tends to be diverse and complicated. Complex signs that contain multiple destinations or other information must be considered to determine not only the proper size, color, etc. but also the most effective arrangement of design elements. In the previous research, the cognitive utility of complex public signs was estimated using computer simulation software. In the current research, we focused on the objective estimation of the effectiveness of the results obtained in the previous research utilizing an eye mark recording system. Two cognitive engineering experiments clarified five points for improvement in the usability of complex signs, as follows: 1) Parallel construction of characters and pictograms is more efficient. 2) Grouping elements result in rapid recognition of information chunks. 3) Visual characters and pictograms are effective, along with proper density of information. 4) Specific arrangement of sign arrows is effective. 5) Figures on signs influence the sequence of information searches.

• The Research Journal of the Costume Culture
• /
• v.10 no.3
• /
• pp.213-235
• /
• 2002

The purpose of this study was to recognize the meanings of plastic language by analyzing the sign of the Graffiti depicted in western modern costumes. And the scope of this study was focused on analysing the costumes from 1980's when the Graffiti was recognized as one of the plastic arts. Graffiti was an unprofessional and covert desire of self-expression, having a close relation with our lives. It was used in diverse ways with repeating creation, development, and extinction, from expressing liveliness in Old Stone Age through describing symbolic meaning in the modern art. Graffiti means rude, humorous, or political writing and pictures on the walls of buildings. It's different from the delicate letters or pictures to inscript on the tree or rocks. Being introduced as part of Post-modernism in the 1970s, Graffiti was acknowledged as a new artistic action with the culture of hip-hop. In addition the Graffiti, the expression of sign was reflected artist's internal consciousness with boundless sign. The sign is something to transmit message from the nonverbal point of view, the oldest sign was the sign for petition or the expression of something as a primitive form. Sign can be defined as a framework of life inherited as a practice from the primitive age long past. Graffiti was cited as a concrete example of sign, theme of this paper, and general understanding on sign expression was pursued through free work which all artists present with essential and positive ways using signs, their own languages, and life style. The result of this study was summarized as follows: Since the end of the 20th century, a lot of fashion designers have represented symbolic images, such as letter and signs, as purely personal ways of expression through the western costumes. It was found that fashion designers of the Graffiti whose free work style from inherent inner consciousness might provide a basic framework to search for complex signs of modem costumes naturally understood life itself as plastic art, and sublimated human inherent desire and their inner world through their works.

• Journal of the Ergonomics Society of Korea
• /
• v.18 no.1
• /
• pp.133-147
• /
• 1999

Traffic signs without a cognitive consideration in their design may cause information-processing problem that could result in a mental confusion among drivers often lead to a serious traffic accident. Therefore, in this study, several traffic signs currently used in Seoul Metropolitan area have been sampled and analyzed to identify design problems that usually caused by neglecting drivers cognitive ability. To classify the practical design problems, five major information-processing problems have been suggested: indistinguishable information, information conflict, missing information, sign-load mismatch, and information overload. In order to solve these cognitive problems, new traffic signs have been suggested in this study. An experiment was also performed to validate the new traffic sign. Twenty-four healthy subjects participated in the experiment. They were asked to answer the Question after observing the traffic signs continuously displayed on computer screen. The result indicated that subjects improved the accuracy in understanding the signs by 1.4 times when they used the suggested traffic sign compared to the old one. Based upon the results, a cognitive guideline was suggested for correct and speedy reading of traffic signs by improving information processing and reducing of human error. In conclusion, the traffic sign may well be applied to design an intelligent traffic sign system to increase the safety and comfort of drivers, especially in complex load condition.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2011.10a
• /
• pp.415-418
• /
• 2011

This paper describes a circuit-level optimization of DFU(decoding function unit) for LDPC decoder which is used in wireless communication systems such as WiMAX and WLAN. The conventional DFU which is based on min-sum decoding algorithm needs conversions between two's complement values and sign-magnitude values, resulting in complex hardware. In this paper, a new design of DFU that is based on sign-magnitude arithmetic is proposed to achieve a simplified circuit and high-speed operation.