• JSTS:Journal of Semiconductor Technology and Science
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• v.8 no.1
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• pp.11-20
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• 2008

The structure of 2-bit/cell flash memory device was characterized for sub-50 nm non-volatile memory (NVM) technology. The memory cell has spacer-type storage nodes on both sidewalls in a recessed channel region, and is erased (or programmed) by using band-to-band tunneling hot-hole injection (or channel hot-electron injection). It was shown that counter channel doping near the bottom of the recessed channel is very important and can improve the $V_{th}$ margin for 2-bit/cell operation by ${\sim}2.5$ times. By controlling doping profiles of the channel doping and the counter channel doping in the recessed channel region, we could obtain the $V_{th}$ margin more than ${\sim}1.5V$. For a bit-programmed cell, reasonable bit-erasing characteristics were shown with the bias and stress pulse time condition for 2-bit/cell operation. The length effect of the spacer-type storage node is also characterized. Device which has the charge storage length of 40 nm shown better ${\Delta}V_{th}$ and $V_{th}$ margin for 2-bit/cell than those of the device with the length of 84 nm at a fixed recess depth of 100 nm. It was shown that peak of trapped charge density was observed near ${\sim}10nm$ below the source/drain junction.

• Wind and Structures
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• v.30 no.2
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• pp.211-217
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• 2020

Vibrations of a wind turbine blade have a negative impact on its performance and result in failure of the blade, therefore an approach to effectively control vibration in turbine blades are sought by wind industry. The small domestic horizontal axis wind turbine blades induce flap wise (out-of-plane) vibration, due to varying wind speeds. These flap wise vibrations are transferred to the structure, which even causes catastrophic failure of the system. Shape memory alloys which possess physical property of variable stiffness across different phases are embedded into the composite blades for active vibration control. Previously Shape memory alloys have been used as actuators to change their angles and orientations in fighter jet blades but not used for active vibration control for wind turbine blades. In this work a GFRP blade embedded with Shape Memory Alloy (SMA) and tested for its vibrational and material damping characteristics, under martensitic and austenite conditions. The embedment portrays 47% reduction in displacement of blade, with respect to the conventional blade. An analytical model for the actuated smart blade is also proposed, which validates the harmonic response of the smart blade.

• Phonetics and Speech Sciences
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• v.8 no.1
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• pp.63-69
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• 2016

The aims of the present study are two-fold: 1) to explore differences on speech perception between younger and older adults according to noise conditions; and 2) to investigate which cognitive domains are correlated with speech perception. Data were acquired from 15 younger adults and 15 older adults. Sentence recognition test was conducted in four noise conditions(i.e., in-quiet, +5 dB SNR, 0 dB SNR, -5 dB SNR). All participants completed auditory and cognitive assessment. Upon controlling for hearing thresholds, the older group revealed significantly poorer performance compared to the younger adults only under the high noise condition at -5 dB SNR. For older group, performance on Seoul Verbal Learning Test(immediate recall) was significantly correlated with speech perception performance, upon controlling for hearing thresholds. In older adults, working memory and verbal short-term memory are the best predictors of speech-in-noise perception. The current study suggests that consideration of cognitive function for older adults in speech perception assessment is necessary due to its adverse effect on speech perception under background noise.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.3
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• pp.374-380
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• 2022

This paper shows the results of a study that predicts changes in seawater conditions in sea farms using machine learning-based long short term memory (LSTM) algorithms. Hardware was implemented using dissolved oxygen, salinity, nitrogen ion concentration, and water temperature measurement sensors to collect seawater condition information from sea farms, and transferred to a cloud-based Firebase database using LoRa communication. Using the developed hardware, seawater condition information around fish farms in Tongyeong and Geoje was collected, and LSTM algorithms were applied to learning results using these actual datasets to obtain predictive results showing 87% accuracy. Flask and REST APIs were used to provide users with predictive results for each of the four parameters, including dissolved oxygen. These predictive results are expected to help fishermen reduce significant damage caused by fish group death by providing changes in sea conditions in advance.

• Korean Journal of Cognitive Science
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• v.13 no.4
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• pp.9-21
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• 2002

Four experiments were conducted to examine whether maintaining the same conceptual context across study and test would affect performance on a perceptual implicit memory task. The sense-specific theory of priming (Lewandowsky et al., 1989) predicts greater priming from a match in conceptual context across study and test compared with a condition in which the conceptual context is mismatched, whereas the transfer-appropriate-processing view (e.g., Blaxton, 1989) predicts no difference. In experiment 1 and 2, little or no effect of varying context was observed on a implicit task. In experiment 3 and 4, a process-dissociation procedure (proposed by Jacoby, 1991) was used to separate automatic influences from consciously controlled influence in implicit memory, which was measured by Korean word completion task. The results showed that conceptual context effect was observed in consciously controlled parts of implicit memory. These results suggest that only consciously controlled processing parts of implicit memory is sensitive to conceptual context.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.2
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• pp.59-66
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• 2013

In this paper, we proposed an optimal ILP algorithm on memory address code generation for DSP in embedded system. This paper using 0-1 ILP formulations DSP address generation units should minimize the memory variable data layout. We identify the possibility of the memory assignment of variable based on the constraints condition, and register the address code which a variable instructs in the program pointer. If the process sequence of the program is declared to the program pointer, then we apply the auto-in/decrement mode about the address code of the relevant variable. And we minimize the loads on the address registers to optimize the data layout of the variable. In this paper, in order to prove the effectiveness of the proposed algorithm, FICO Xpress-MP Modeling Tools were applied to the benchmark. The result that we apply a benchmark, an optimal memory layout of the proposed algorithm then the general declarative order memory on the address/modify register to reduce the number of loads, and reduced access to the address code. Therefor, we proved to reduce the execution time of programs.

• Korean Journal of Cognitive Science
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• v.29 no.1
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• pp.39-59
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• 2018

To elucidate the effect of working memory (WM) load on negative facial emotion processing, we examined ERP components (P1 and N170) elicited by fearful and neutral expressions each of which was presented during 0-back (low-WM load) or 2-back (high-WM load) tasks. During N-back tasks, visual objects were presented one by one as targets and each of facial expressions was presented as a passively observed stimulus during intervals between targets. Behavioral results showed more accurate and fast responses at low-WM load condition compared to high-WM load condition. Analysis of mean amplitudes of P1 on the occipital region showed significant WM load effect (high-WM load > low-WM load) but showed nonsignificant facial emotion effect. Analysis of mean amplitudes of N170 on the posterior occipito-temporal region showed significant overall facial emotion effect (fearful > neutral), but, in detail, significant facial emotion effect was observed only at low-WM load condition on the left hemisphere, but was observed at high-WM load condition as well as low-WM load condition on the right hemisphere. To summarize, facial emotion effect observed by N170 amplitudes was modulated by WM load only on the left hemisphere. These results show that early emotional processing of negative facial expression could be eliminated or reduced by high load of WM on the left hemisphere, but could not be eliminated by high load on the right hemisphere, and suggest right hemispheric lateralization of negative facial emotion processing.

• Korean Journal of Cognitive Science
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• v.18 no.2
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• pp.159-178
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• 2007

Lee & Kang (2002) showed that simultaneous phonological rehearsal significantly delayed the performance of multiplication but not subtraction, whereas holding an image in the memory delayed subtraction but not multiplication. This result indicated that arithmetic function is related to working memory in a subsystem-specific manner. The aim of the current study was to examine the neural correlates of previous finding using fMRI. For this goal, dual task conditions that required suppression or no suppression were manipulated. In general, several areas were more activated in the interference conditions than in the less interference conditions, although both conditions were dual condition. More important finding is that the specific areas activated in the phonological suppression rendition were right inferior frontal gyrus, left angular, and inferior parietal lobule, while the areas activated in the other condition were mainly in the right superior temporal gyrus and anterior cingulate gyrus. Furthermore, the areas activated in the phonological or visual less suppression condition were right medial frontal gyrus, left middle frontal gyrus, and bilateral medial frontal gyri, anterior cingulate cortices, and parahippocampal gyri, respectively. These results revealed that sharing the processing code invokes interference, and its neural basis.

• The Journal of the Acoustical Society of Korea
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• v.9 no.4
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• pp.77-85
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• 1990

This study investigated Greene and Corwder(1984)'s modified PAS model, according to which, in a short-term memory recall task, the recency and suffix effects existing in auditory and visual conditions are mediated by the same mechanisms. It also investigated whether the auditory information and mouthed information are encoded by the same codes. Though the experimental manipulation of the phonological nature, the presence of differential recall effect of consonant-and vowel-varied stimuli in auditory and mouthing conditions which has been supposed to interact with the recency and suffix effects, was investigated. The result shows that differential recall effect between consonant and vowel exists only in the auditory condition, but not in the mouthing condition. Thus, this result supported Turner.

• Korean Journal of Child Studies
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• v.7 no.1
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• pp.67-84
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• 1986

The purpose of the present research was to investigate cross-modal transfer, especially tactual-to-visual transfer in infancy and to study the relation between failure of cross-modal transfer performance and length of familiarization period. The subjects of this study were 60 infants, 10 boys and 10 girls at each level: six, nine, and twelve months of age. All were normal, healthy, full-term babies. The mothers' educational achievement was controlled at more than 12 years of schooling. There were two separate experimental conditions, one 30-sec and one 60-sec familiarization period. Each experimental condition consisted of a tactual familiarization and a visual recognition memory test. Each child was presented with these 2 sets of cross-modal stimuli in one of the 2 experimental conditions. Infants' visual responses in the visual recognition memory test were videotaped for 20 seconds. Visual fixation time to novel and familiar stimuli was observed throughout the test. The data was analyzed with t-test, percentage of total fixation time to novel stimuli, and ANOVA. The results showed that: 1) Significant differences were found in the cross-modal transfer performance from touch to vision between the 3 age groups. This is, 6 and 9 month old infants didn't show cross-modal transfer in the 30-sec condition, but 12 month old infants did show cross-modal transfer in the 30-second. 2) In all 3 age groups, no significant differences were found in cross-modal transfer performance between the two conditions.