• Current Optics and Photonics
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• v.5 no.1
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• pp.23-31
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• 2021

We propose a wheel screen type Lamina 3D display, which realizes a 3D image that can satisfy the accommodation cue by projecting volumetric images encoded by varying polarization states to a multilayered screen. The proposed system is composed of two parts: an encoding part that converts depth information to states of polarization and a decoding part that projects depth images to the corresponded diffusing layer. Though the basic principle of Lamina displays has already been verified by previous studies, those schemes suffered from a bottleneck of inferior resolution of the 3D image due to the blurring on the surfaces of diffusing layers in the stacked volume. In this paper, we propose a new structure to implement the decoding part by adopting a form of the wheel screen. Experimental verification is also provided to support the proposed principle.

• Current Optics and Photonics
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• v.5 no.1
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• pp.32-39
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• 2021

We propose a three-dimensional (3D) streaming system based on a lamina display that can convey field information in real-time by creating floating 3D images that can satisfy the accommodation cue. The proposed system is mainly composed of three parts, namely: a 3D vision camera unit to obtain and provide RGB and depth data in real-time, a 3D image engine unit to realize the 3D volume with a fast response time by using the RGB and depth data, and an optical floating unit to bring the implemented 3D image out of the system and consequently increase the sense of presence. Furthermore, we devise the streaming method required for implementing augmented reality (AR) images by using a multilayered image, and the proposed method for implementing AR 3D video in real-time non-face-to-face communication has been experimentally verified.

• Phonetics and Speech Sciences
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• v.13 no.2
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• pp.9-17
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• 2021

Voice onset time (VOT) is known to be a primary acoustic cue that differentiates voiced from voiceless stops in the world's languages. While much attention has been given to the sound change of Korean stops, little attention has been given to that of English stops. This study examines VOT of stop consonants as produced by English speakers in comparison to Korean speakers to see whether there is any VOT change for English stops and how the effects of stop, place, gender, and individual on VOT differ cross-linguistically. A total of 24 native speakers (11 Americans and 13 Koreans) participated in this experiment. The results showed that, for Korean, the VOT merger of lax and aspirated stops was replicated, and, for English, voiced stops became initially devoiced and voiceless stops became heavily aspirated. English voiceless stops became longer in VOT than Korean counterparts. The results suggest that, similar to Korean stops, English stops may also undergo a sound change. Since it is the first study to be revealed, more convincing evidence is necessary.

• American Studies
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• v.44 no.1
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• pp.113-135
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• 2021

The Civil War is widely accepted as the single most meaningful event in American history that overcame the most fatal crisis of internal division of the nation with much success. That meaningfulness in turn glorifies the North's triumph over the South and justifies hierarchical differences between the two. Yet, as shown in the studies of Civil War literature, such glorification and justification relies too much on the North-centered historical paradigm. This essay aims to offer a way of rectifying it by examining a short story by one of the persistently obscured writers of the period: Elizabeth Stoddard. The essay follows the cue of Alice Fahs's cultural-studies methodology of using popular wartime periodicals as the main resource of the war literature, and reads Stoddard's "Sally's Choice" as one of the examples that expose the hegemonic bias inside the North-directed discourse of the time. This essay is expected to demonstrate the necessity of expanding and deepening our conception of 'literature,' 'the Civil War,' and 'Civil War literature' in an ever-flexible and ever-changeable manner.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2022.06a
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• pp.58-60
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• 2022

본 논문에서는 복소(complex) 공간큐를 활용한 다채널 오디오 부호화 기술을 제안한다. 복소 공간큐 방식의 다채널 오디오 부호화 기술은 시간영역에서 수행된다. 시간영역의 오디오 채널 신호를 복소 데이터로 변환하여 각 오디오 채널 간의 상관관계를 복소 공간큐로 표현하고, 이를 활용하여 채널 부호화를 수행하기 위한 오디오 채널 신호를 생성한다. 참조 기술로는 최고 성능의 오디오 코덱인 USAC의 예측 부호화 방식의 다채널 오디오 부호화 기술과 비교하여 정보량 감축 측면에 있어서 평균 2.24 dB 이상의 높은 SNR을 나타냄을 관측할 수 있었다.

• Phonetics and Speech Sciences
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• v.14 no.4
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• pp.11-17
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• 2022

This study investigates closure durations of Korean stops in terms of laryngeal contrasts, places of articulation, and three positions within words. Twenty-two Korean speakers produced the nonsense words containing Korean stops found in word-initial and word-final positions and between vowels. The statistical results showed that the closure durations differed significantly by laryngeal contrast and place of articulation. In addition, the differences by position within words were marginally significant. The closure durations were in the order of lenis < aspirated < fortis stops by laryngeal contrast, velar < alveolar < bilabial stops by place of articulation, and word-final < word-initial < between vowels by positions within words. The laryngeal contrasts were neutralized in word-final position as per coda neutralization in Korean phonology. This study shows that closure durations should be considered a valuable phonetic cue to identify stops on par with voice onset time and f0.

• Korean Journal of Cognitive Science
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• v.28 no.4
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• pp.193-221
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• 2017

Grouping episodes into semantically related categories is necessary for better mnemonic structure. However, the effect of grouping on memory of subordinate details was not clearly understood. In an fMRI study, we tested whether attending superordinate during semantic association disrupts or enhances subordinate episodic details. In each cycle of the experiment, five cue words were presented sequentially with two related detail words placed underneath for each cue. Participants were asked whether they could imagine a category that includes the previously shown cue words in each cycle, and their confidence on retrieval was rated. Participants were asked to perform cued recall tests on presented detail words after the session. Behavioral data showed that reaction times for categorization tasks decreased and confidence levels increased in the third trial of each cycle, thus this trial was considered to be an important insight where a semantic category was believed to be successfully established. Critically, the accuracy of recalling detail words presented immediately prior to third trials was lower than those of followed trials, indicating that subordinate details were disrupted during categorization. General linear model analysis of the trial immediately prior to the completion of categorization, specifically the second trial, revealed significant activation in the temporal gyrus and inferior frontal gyrus, areas of semantic memory networks. Representative Similarity Analysis revealed that the activation patterns of the third trials were more consistent than those of the second trials in the temporal gyrus, inferior frontal gyrus, and hippocampus. Our research demonstrates that semantic grouping can cause memories of subordinate details to fade, suggesting that semantic retrieval during categorization affects the quality of related episodic memory.

• Korean Journal of Cognitive Science
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• v.27 no.4
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• pp.573-597
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• 2016

Recent fMRI and EEG research for neural representations of action concepts insist that processing of action concepts evoke the simulation of sensory-motor information. Moreover, there are several behavioral studies showing that understanding of action verbs or sentences describing actions interfere or facilitate current action performance. However, it is unclear that online interaction between processing of action concepts and current action is based on the simulation of sensory-motor information, or other neural mechanisms. The present research aims to explore the underlying neural mechanism that how the perception of action language influence the performance of current action using high-spacial temporal resolution EEG and multiple source analysis techniques. For this, participants were asked to perform a cued-motor reaction task in which button-pressing hand action and pedal-stepping foot action were required according to the color of the cue, and we presented auditorily action verbs describing the responding actions (i.e., /press/, /step/, /stop/) just before the color cue and examined the interaction effect from the semantic congruency between the action verbs and the current action. Behavioral results revealed consistently a facilitatory effect when action verbs and responding actions were semantically congruent in both button-pressing and pedal-stepping actions, and an inhibitory effect when semantically incongruent in the button-pressing action condition. In the results of EEG source waveform analysis, the semantic congruency effects between action verbs and the responding actions were observed in the Wernicke's area during the perception of action verbs, in the anterior cingulate gyrus and the supplementary motor area (SMA) at the time when the motor-cue was presented, and in the SMA and primary motor cortex (M1) during action execution stage. Based on the current findings, we argue that perceived action verbs evoke the facilitation/inhibition effect by influencing the expectation and preparation stage of following actions rather than the directly activating the particular motor cortex. Finally we discussed the implication on the neural representation of action concepts and methodological limitations of the current research.

• Korean Journal of Cognitive Science
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• v.34 no.3
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• pp.153-180
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• 2023

Previous research on the action effect had shown how simple action towards a stimulus can enhance the processing of that stimulus in subsequent visual search task (Buttaccio & Hahn, 2011; Weidler & Abrams, 2014). In four experiments, we investigated whether semantic representation of action word can induce the same attentional boost towards that stimulus and whether the type of action performed can modulate the action effect. In experiment 1, we replicated the same experimental paradigm displayed in previous studies. Participants were first shown an action word cue - "go" or "no". When the action cue was "go", participants were to press a designated key, but not to when the action cue was "no". Next, participants performed a visual search task, in which they reported the orientation of a tilted bar. The target could appear on top of the previously shown prime object (valid), or not (invalid). Reaction times (RTs) to the search task were measure for analysis and comparison, and the action effect had been replicated. In experiment 2, participants were instructed to respond with the keyboard for the action task, and to respond with the joystick for the visual search task. In experiment 3, participants were instructed not to press any key on the onset of prime, and then perform the visual search task to isolate the effect of semantic representation. Lastly, in experiment 4, participants were instructed to press separate keys for "go" and "no" on the onset of prime, and then perform the visual search task. Results indicate that semantic representation alone did not modulate the action effect, regardless of type of action and medium of action.

• Journal of Acupuncture Research
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• v.24 no.3
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• pp.215-229
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• 2007

Objectives : Placebo phenomena have been considered as a confounding factor of clinical trial. Expectancy and belief of acupuncture have not been evaluated quantitatively. The present study was performed to analyze the emotional and cognitive factor .of acupuncture and investigate whether the expectancy of acupuncture treatment is associated with the cognition of acupuncture. Methods : The expectancy and the perception of bodily sensation (PBS) of 22 participants were assessed using self-reported questionnaire. The subjects used the self assessment manikin (SAM) to rate each of the standard affective image of the international affective picture system (lAPS) and other acupuncture-related image. Based on the degree of expectancy, the high expectant (HE) and the low expectant (LE) group were classified. The thermal and pressure pain threshold was objectively evaluated using radiant-heat device and algometer. The degree of expected pain of acupuncture and the actual pain of painful stimulation was subjectively evaluated using facial pain scales (FPS). Results : Using SAlVI analysis, we identified the negative correlation between hedonic valence and arousal dimension on acupuncture-related visual cue. The degree of the PBS and general pain threshold did not show any significant difference between the HE and the LE group. The HE group rated the acupuncture images as more pleasant, more arousing, than the LE group. In addition, we also found that the higher expectancy marked the lower FPS of the expected pain of acupuncture, but not of the actual pain of painful stimulation. Conclusions : Our preliminary study identified the psychological dimensions of acupuncture-related visual cue. These findings indicate that the expectancy of acupuncture could affect the cognition of acupuncture.