• Korean journal of applied entomology
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• v.50 no.4
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• pp.383-393
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• 2011

Because communication facilitates behaviors that are critical for survival and reproduction, it is central to the study of behavior and evolution. One of the most important and difficult issues with respect to communication has been the definition of communication itself. Broadly, it can be defined as an exchange of information from a signaler to a receiver. However, evolution of a signal is likely possible only under conditions in which both the signaler and receiver increase fitness from the exchange of information, often referred to as "true communication." The three primary sensory channels of communication used by animals are chemical, visual, and acoustic. Chemical signals are the oldest and most widespread method of communication. Visual and acoustic signals convey a great deal of information due to ease of modulation, flexibility of signal production, and fast transmission. The most widespread contexts in which animals communicate are sexual interaction and conflict resolution. Signals used for sexual interaction typically contain information about species identity and sexual attractiveness, whereas signals used for conflict resolution may contain information about resource holding potential. Other contexts under which animals communicate include territorial defense, parent-offspring interactions, social integration, sharing of environmental information, and auto-communication.

• Journal of the Institute of Convergence Signal Processing
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• v.19 no.1
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• pp.7-13
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• 2018

In the current study, we proposed an optimized brain-computer interface (BCI) which employed blind source separation (BBS) approach to remove noises. Thus motor imagery (MI) signal and steady state visual evoked potential (SSVEP) signal were easily to be detected due to enhancement in signal-to-noise ratio (SNR). Moreover, a combination between MI and SSVEP which is typically can increase the number of commands being generated in the current BCI. To reduce the computational time as well as to bring the BCI closer to real-world applications, the current system utilizes a single-channel EEG signal. In addition, a convolutional neural network (CNN) was used as the multi-class classification model. We evaluated the performance in term of accuracy between a non-BBS+BCI and BBS+BCI. Results show that the accuracy of the BBS+BCI is achieved $16.15{\pm}5.12%$ higher than that in the non-BBS+BCI by using BBS than non-used on. Overall, the proposed BCI system demonstrate a feasibility to be applied for multi-dimensional control applications with a comparable accuracy.

• Journal of Yeungnam Medical Science
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• v.37 no.2
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• pp.90-97
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• 2020

Background: To minimize damage to the ovarian reserve, it is necessary to evaluate the follicular density in the ovarian tissue surrounding endometriosis on preoperative imaging. The purpose of the present study was to evaluate the usefulness of subtraction pelvic magnetic resonance imaging (MRI) to detect ovarian reserve. Methods: A subtracted T1-weighted image (^subT1WI) was obtained by subtracting unenhanced T1WI from contrast-enhanced T1WI (^ceT1WI) with similar parameters in 22 patients with ovarian endometriosis. The signal-to-noise ratio (SNR) in ovarian endometriosis, which was classified into the high signal intensity and iso-to-low signal intensity groups on the T2-weighted image, was compared to that in normal ovarian tissue. To evaluate the effect of contrast enhancement, a standardization map was obtained by dividing ^subT1WI by ^ceT1WI. Results: On visual assessment of 22 patients with ovarian endometriosis, 16 patients showed a high signal intensity, and 6 patients showed an iso-to-low signal intensity on T1WI. Although SNR in endometriosis with a high signal intensity was higher than that with an iso-to-low signal intensity, there was no difference in SNR after the subtraction (13.72±77.55 vs. 63.03±43.90, p=0.126). The area of the affected ovary was smaller than that of the normal ovary (121.10±22.48 vs. 380.51±75.87 ㎟, p=0.002), but the mean number of pixels in the viable remaining tissue of the affected ovary was similar to that of the normal ovary (0.53±0.09 vs. 0.47±0.09, p=0.682). Conclusion: The subtraction technique used with pelvic MRI could reveal the extent of endometrial invasion of the normal ovarian tissue and viable remnant ovarian tissue.

• Journal of radiological science and technology
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• v.46 no.2
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• pp.115-122
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• 2023

The purpose of this study was to examine the association between the shapes and colors of emergency exit symbols, magnetic field warning symbols, and radiation zone symbols used in hospitals for staff and patient safety and their effects on cognitive memory. The hippocampal region's signal intensity(SI) was analyzed using fMRI. The Symbol 2 (1.75±0.54) with a green background had the highest signal intensity (SI) for emergency exits, according to the findings. The black symbol 2 (1.60±0.51) with a yellow background had the highest signal intensity (SI) for the magnetic field warning symbol, followed by the black symbol 1 (1.59±0.65) with an orange background. The black symbol 2 (1.59±0.59) with a yellow background and the black symbol 3 (1.58±0.52) with an orange background had the low signal intensity with slight differences as for the radiation zone symbols. In conclusion, it was determined that the signal intensity of the black symbol with a yellow background was the highest in the magnetic field area and radiation area. This implies that symbols with a high signal intensity (SI) must be utilized intensively. To ensure that the correct meaning of the symbols is communicated in the future, they must also be utilized regularly and continually in disaster safety education.

• Korean Journal of Radiology
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• v.20 no.1
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• pp.126-133
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• 2019

Objective: To compare the lumbar vertebral bone marrow fat-signal fractions obtained from six-echo modified Dixon sequence (6-echo m-Dixon) with those from single-voxel magnetic resonance spectroscopy (MRS) in patients with low back pain. Materials and Methods: Vertebral bone marrow fat-signal fractions were quantified by 6-echo m-Dixon (repetition time [TR] = 7.2 ms, echo time (TE) = 1.21 ms, echo spacing = 1.1 ms, total imaging time = 50 seconds) and single-voxel MRS measurements in 25 targets (23 normal bone marrows, two focal lesions) from 24 patients. The point-resolved spectroscopy sequence was used for localized single-voxel MRS (TR = 3000 ms, TE = 35 ms, total scan time = 1 minute 42 seconds). A 2 × 2 × 1.5 cm³ voxel was placed within the normal L2 or L3 vertebral body, or other lesions including a compression fracture or metastasis. The bone marrow fat spectrum was characterized on the basis of the magnitude of measurable fat peaks and a priori knowledge of the chemical structure of triglycerides. The imaging-based fat-signal fraction results were then compared to the MRS-based results. Results: There was a strong correlation between m-Dixon and MRS-based fat-signal fractions (slope = 0.86, R² = 0.88, p < 0.001). In Bland-Altman analysis, 92.0% (23/25) of the data points were within the limits of agreement. Bland-Altman plots revealed a slight but systematic error in the m-Dixon based fat-signal fraction, which showed a prevailing overestimation of small fat-signal fractions (< 20%) and underestimation of high fat-signal fractions (> 20%). Conclusion: Given its excellent agreement with single-voxel-MRS, 6-echo m-Dixon can be used for visual and quantitative evaluation of vertebral bone marrow fat in daily practice.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1918-1920
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• 2005

The color and structure of urban constructions is a factor of urban landscape and shows their characteristics. Hence the modern buildings with their materials and external appearance makes up the urban image. But still yet, it was not easy to evaluate the value of visual landscape of buildings with objective measuring method. Most of all, it depends on the subjective estimation of a few talented or high educated experts with a sense of beauty. In relation to this kind of problems, it was tried here in this study to analyse the human response of brain wave pattern (EEG) with use of SD method, while the tested persons watched the urban landscape constructed in a visual reality. The tested persons were 10 adult males and females with no color blindness and intact cognitive function. Light source with color filter was used for color environment in chamber room. The signal of EEG is analysed digitally and grouped into the $\alpha$ and $\beta$ waves. The result showed that relative power of $\alpha$ wave ratio increased in natural landscape scenary clearly. From these results it was possible to evaluate the human response, which was affected by urban color and structure stimulation and it might be useful as an indicator of visual cognition amenity toward the design of urban construction environment.

• Journal of Environmental Science International
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• v.15 no.4
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• pp.305-310
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• 2006

The color and structure of urban constructions is a factor of urban landscape and shows their characteristics. Hence the modern buildings deal with their materials and external appearance as an important factor, making up the urban image. But it was nearby impossible to evaluate the value of visual landscape with objective measuring method. Most of all, it depends on the subjective estimation of a few talented or high educated experts with a sense of beauty. Such kinds of estimation can in some cases include arbitrary interpretations. In relation to this kind of problems, it is tried here in this study to analyse the human response of brain wave pattern (EEG) with use of SD method, while the tested persons watch the urban landscape scenery constructed in a visual reality. The tested persons were 20 adult male and female with no color blindness and intact cognitive function. Light source with color filter was used for color environment in a dark soundproof chamber. The signal of EEG is analysed digitally and grouped into the ${\alpha}$ and ${\beta}$ waves. The result showed that relative power of ${\alpha}$ wave ratio increased in the natural landscape scenery with blue and green color. From these results it was possible to evaluate the human response, which is affected by urban and natural color and structure stimulation and it might be useful as an indicator of visual cognition amenity toward the design of urban construction environment.

• The Journal of the Acoustical Society of Korea
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• v.33 no.5
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• pp.326-334
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• 2014

This paper proposes a novel covariance matrix estimation scheme for minimum variance distortionless response (MVDR) beamforming. By accurately tracking direction-of-sound source arrival (DoA) information using audio-visual sensors, the covariance matrix is efficiently estimated by adopting a variable forgetting factor. The variable forgetting factor is determined by considering signal-to-interference ratio (SIR). Experimental results verify that the performance of the proposed method is superior to that of the conventional one in terms of interference/noise reduction and speech distortion.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2000.10a
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• pp.39-45
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• 2000

A small camera module fabricated by including bare chip bonding methods is utilized to realize advanced mobile devices. One of the driving forces is the TOG (Tape On Glass) bonding method which reduces the packaging size of the image sensor clip. The TOG module is a new thinner and smaller image sensor module, using flip chip interconnection method with the ACP (Anisotropic Conductive Paste). The TOG production process was established by determining the optimum bonding conditions for both optical glass bonding and image sensor clip bonding lo the flexible PCB. The bonding conditions, including sufficient bonding margins, were studied. Another bonding method is the flip chip bonding method for DSP (Digital Signal Processor) chip. A new AC\ulcorner was developed to enable the short resin curing time of 10 sec. The bonding mechanism of the resin curing method was evaluated using FEM analysis. By using these flip chip bonding techniques, small camera module was realized.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.2
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• pp.129-140
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• 2023

Autonomous driving systems are likely to be operated in various complex environments. However, the well-known integrated Global Navigation Satellite System (GNSS)/Inertial Navigation System (INS), which is currently the major source for absolute position information, still has difficulties in accurate positioning in harsh signal environments such as urban canyons. To overcome these difficulties, integrated Visual/Inertial/GNSS (VIG) navigation systems have been extensively studied in various areas. Recently, a Compressed-State Constraint Kalman Filter (CSCKF)-based VIG navigation system (CSCKF-VIG) using a monocular camera, an Inertial Measurement Unit (IMU), and GNSS receivers has been studied with the aim of providing robust and accurate position information in urban areas. For this new filter-based navigation system, on the basis of time-propagation measurement fusion theory, unnecessary camera states are not required in the system state. This paper presents a performance evaluation of the CSCKF-VIG system compared to other conventional navigation systems. First, the CSCKF-VIG is introduced in detail compared to the well-known Multi-State Constraint Kalman Filter (MSCKF). The CSCKF-VIG system is then evaluated by a field experiment in different GNSS availability situations. The results show that accuracy is improved in the GNSS-degraded environment compared to that of the conventional systems.