• Korean Journal of Cognitive Science
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• v.10 no.3
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• pp.51-66
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• 1999

Selective attention induces perceptual distortions. ranging from repulsion of objects located near the attended area(Suzuki & Cavanagh. 1997) to magnification of the u unattended objects (Tsal & Shalev. 1996). Two hypothetical mechanisms have been p postulated: a shift of receptive fields' positions away from the locus of attention(receptive-field-recruitment hypothesis) or the enlargement of perceived space around the a attended location(space-enlargement hypothesis). The present study distinguished between these hypotheses by investigating the spatial and temporal properties of attention-induced d distortions. Perceptual judgements on vernier alignment. line tilt. line length were used to measure attention-induced changes in perception. Attention was induced exogenously(by blinking a specific set of dots around the test stimuli} or endogenously(by instructing the subject to selectively attend the dots). After inducing attention. the test stimuli were briefly flashed. A staircase method was used to measure the attentional effect. A vertical line was perceived as repelled from the locus of attention. and a line segment appeared longer when attention was given to its vicinity. The effects decreased as the distance between the locus of attention or the time between the onset of attention and the stimulus presentation increased. The results imply that the space-enlargement hypothesis provides a better explanation for the attention-induced changes in perception than the receptive-field-recruitment hypothesis.

• Proceedings of the KAIS Fall Conference
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• 2010.11b
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• pp.595-598
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• 2010

본 연구의 목적은 뇌졸중으로 인한 만성 편마비 환자를 대상으로 발에 시지각 자극을 적용하여 균형과 보행에 관한 운동기능에 미치는 효과를 알아보고자 하였다. 6개월 이상 된 편마비 환자 16명이 연구에 참여하였고, 무작위로 실험군(EG) 10명과 대조군(CG) 10명으로 구분하였다. 두 군 모두 기본적인 물리치료를 적용하였고 실험군은 정적균형도구인 Tetrax Multiple System을 이용하여 발목에 감각되먹임 시지각 자극을 매회 30분, 4주간 주 3회 실시하였다. 운동 중재 전과 후의 운동기능에 해당하는 균형(TUG), 보행(DGI)을 측적하여 본 연구의 효과를 비교하였다. 실험군에서 정적 균형, TUG, 그리고 동적 균형지수(DGI) 지수는 중재 전후 통계적으로 유의한 차이를 나타냈고(p<.05), 실험, 대조군간 전후의 변화율에서도 유의한 차이가 나타났다(p<.05). 대조군에서는 DGI 만 중재 전후 통계적으로 유의한 차이가 나타났다. 순수하게 유산소 운동만을 실시하였다. 통계처리 방법으로 전 후 차이를 검증하기 위하여 대응표본 t 검정을 실시하였고 대조군과의 차이 검증을 위하여 독립표본 t 검정을 실시하였다. 모든 통계적 유의수준은 0.05로 하였다. 본 연구에서는 편마비 환자에게 흥미를 촉진하고 운동 기능 회복의 효과를 강화할 수 있는 감각 되먹임이 동반된 시지각 자극을 적용하여 균형 및 보행기능의 향상을 얻을 수 있었고, 차후 연구는 장기간의 추적 관찰 연구가 지속되어야 하고 발목 뿐만 아니라 다른 관절에서의 비교연구가 필요할 것이다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2002.11a
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• pp.187-190
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• 2002

본 논문에서는 잡음 환경에서의 사람의 청각 시스템에서의 신호 에너지에 대한 지각(perception) 패턴을 나타내는 임계 대역에서의 여기(excitation)에너지와 이러한 신호 에너지 사이의 지각적인 간섭 효과를 나타내는 마스킹 특성을 이용하여 지각적인 컨벌루션 잡음(covolutional noise)해석을 통한 잡음 제어 기법을 연구하였다. 이러한 지각적 컨벌루션 잡음은 지각 영역에서 잡음 에너지에 의한 간섭 현상의 영향을 나타내며, 신호의 지각 적인 특성 변화 및 부가 잡음(additional noise) 제어 후에 신호 내에 잔존하는 잔여 노이즈를 반영하는 것이다. 실험 결과 부가 잡음 제어 필터와 컨벌루션 잡음 제어 필터가 대등한 노이즈 제어 성능을 나타내었으며, 다양한 잡음 환경에서 이러한 지각 영역에서의 부가 잡음 제어와 컨벌루션 잡음 제어를 통해 높은 SNR비 개선과 더불어 MOS 측정을 통해서도 높은 음질을 보장할 수 있음을 확인 할 수 있었다.

• Korean Journal of Cognitive Science
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• v.29 no.1
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• pp.17-38
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• 2018

The purpose of present study was to examine whether the perceived distance is compressed to different extent according to the length of the tool in the object that is not reachable even when using the tool, and whether the perceived distance is compressed according to the tool length only in the object being pointed. In Experiment 1, we found by measuring the egocentric distance that the length of the tool causes the distance to the target to be closer to that of the object placed at a far distance. In Experiment 2, we found by measuring the egocentric distance that when the operated object and the non-operated object coexisted in the visual field, the length of the tool does not affect the distance perception to the non-pointed object. In Experiment 3, we found that the tool length affects only the distance perception of the operated object by measuring the exocentric distance which is the distance between the operated object and the target in the same environment as Experiment 2. The results of present experiment suggest that the compression of the perceived distance occurs at a distance that can not be reached by using the tool, and that the compression of the perceived distance is limited to the pointed object.

• Phonetics and Speech Sciences
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• v.12 no.1
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• pp.11-17
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• 2020

Non-tonal language speakers may have difficulty learning second language lexical tones. In the present study, we explored this issue with Korean-speaking learners of Mandarin Chinese (i.e., non-tonal first language speakers) by examining their perception and production of Mandarin lexical tones. In the perception experiment, the Korean learners were asked to listen to the tone of each stimulus and assign it to one of four Mandarin lexical tones using the response keys; in the production experiment, the learners provided speech production data for the lexical tones and then their productions were identified by native listeners of Mandarin Chinese. Our results showed that the Korean learners of Mandarin Chinese had difficulty in perceptually distinguishing Tone 2 and Tone 3, with the most frequent production error being the mispronunciation of Tone 3 as Tone 2. We also investigated whether unfamiliar non-native phonemes (i.e., Chinese phonemes) that do not exist in the native language phonemic inventory (i.e., Korean) may hinder the processing of the non-native lexical tones. We found no evidence for such effects, neither for the perception nor for the production of the tones.

• Phonetics and Speech Sciences
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• v.15 no.4
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• pp.17-26
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• 2023

This study aimed to reveal how Vietnamese adult learners at three different proficiency levels perceive Korean word-initial obstruents and whether errors can be corrected through perceptual training. To this end, 105 Vietnamese beginner, intermediate, and advanced learners were given perceptual training on Korean word-initial. The training materials were created by actively utilizing Korean minimal pairs as natural stimuli recorded by native speakers. Learners in the experimental group performed five 20-40 minute self-directed perceptual training sessions over a period of approximately two weeks, while learners in the control group only participated in the pretest and posttest. The results showed a significant improvement in the perception of sounds that were difficult to distinguish before training, and both beginners and advanced learners benefited from the training. This study confirmed that large-scale perceptual training can play an important role in helping Vietnamese learners learn the appropriate acoustic cues to distinguish different sounds in Korean.

• Explosives and Blasting
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• v.21 no.1
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• pp.9-17
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• 2003

본 기술사례는 과학기술부가 주도하는 자연재해방재기술개발 국가중점연구사업 중 기상청주관의 기상지진기술개발사업의 한반도 지각속도 구조연구 과제 중 서산지역과 포항지역을 연결하는 200km 측선에서 2차원 지각구조를 밝히기 위한 지각규모 굴절파탐사의 지진동 source 제공을 위해 발파로 실시하였다. 본 연구를 위하여 국내에서는 거의 실행해 본 경우가 없는 지발당 장약량이 500~1000kg발파를 실시하였다. 200개의 계측지점에 지진동이 전달될 수 있도록 충분한 폭속을 가진 폭약과 외부의 충격과 우수한 기폭력, 시차가 정확한 비전기뇌관을 특수 제작하여 사용하였다. 시추공내로 유출되는 물에 의한 사압을 방지하기 위하여 폭약은 철관용기를 제작하여 벌크형태로 장약을 하여 발파를 하였다. 발파전 용기 밀폐 시험 및 용기제작 후 기폭실험, 수압작용으로 인한 폭약 및 뇌관에 미치는 영향 등을 실험을 통하여 사전 파악을 하였다. 또한 실제 발파 중 진동차를 측정한 결과 보안물건에 대한 진동치값은 미광무국식(USBM)을 이용하여 예측한 진동치보다 평균 180% 정도 높게 나타났다.

• Annual Conference on Human and Language Technology
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• 1990.11a
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• pp.235-246
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• 1990

McClelland와 Rumelhart (1981)의 상호작용활성화 모형과 Feigembaum과 Simon (1984)의 초보지각자-기억자 모형 (Elementary Perceiver and Memorizer, EPAM)을 두 음절 한글단어에서의 낱자 지각을 중심으로 검증한 김 재갑과 김 정오 (1990)의 실험을 새 자극 단어들과 변수를 포함시킨 두 실험을 수행하였다. 여섯 낱자들로 구성된 단어의 둘째 음절위치에서 단어 내의 낱자들은 단독으로 제시되는 낱자들보다 더 부정확하게 파악되었고 (단어열등효과), 이 결과는 다섯 낱자로 된 두 음절 단어들에서는 관찰되지 않았고, 그 배후 기제는 세 낱자들로 구성된 단어의 부분에 대한 제한된 주의 용량의 배정임을 시사하는 결과를 얻었다. 본 연구의 결과들은 상호작용활성화 모형보다 EPAM 모형에 의해 더 잘 다루어짐이 밝혀졌다.

• Phonetics and Speech Sciences
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• v.13 no.4
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• pp.23-34
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• 2021

This study aims to discuss how Egyptian learners of Korean perceive and categorize Korean vowels, how Koreans perceive Korean vowels they pronounce, and how Egyptian learners' Korean vowel categorization affects their perception and production of Korean vowels. In Experiment 1, 53 Egyptian learners were asked to listen to Korean test words pronounced by Koreans and choose the words they had listened to among 4 confusable words. In Experiment 2, 117 sound files (13 test words×9 Egyptian learners) recorded by Egyptian learners were given to Koreans and asked to select the words they had heard among 4 confusable words. The results of the experiments show that "new" Korean vowels that do not have categorizable ones in Egyptian Arabic easily formed new categories and were therefore well identified in perception and relatively well pronounced, but some of them were poorly produced. However, Egyptian learners poorly distinguished "similar" Korean vowels in perception, but their pronunciation was relatively well identified by native Koreans. Based on the results of this study, we argued that the Speech Learning Model (SLM) and Perceptual Assimilation Model (PAM) explain the L2 speech perception well, but they are insufficient to explain L2 speech production and therefore need to be revised and extended to L2 speech production.

• Science of Emotion and Sensibility
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• v.23 no.4
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• pp.3-20
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• 2020

The purpose of this study was to investigate the effect of aging on visuo-spatial attention allocation ability and emotional perception bias. We used the useful field of view (UFOV) task to measure the visuo-spatial attention allocation ability and the emotional perception task to measure positive and negative emotional perception bias. A total of 48 participants took part in this study with 23 participants in the senior group and 25 in the junior group. The senior group showed slower response time and lower accuracy than the junior group in the UFOV task, indicating that the senior group had lower visuo-spatial attention allocation ability than the junior group. In the emotional perception task, the senior group showed both positive and negative emotional perception bias more than the junior group. The correlation analysis showed that the negative emotional perception bias for accuracy in the emotional perception task showed a positive correlation with the response time to the stimuli presented in the visual angle 30° in the UFOV task (r=.289). In addition, positive emotional perception bias for the accuracy in the emotional perception task showed a positive correlation with the accuracy of the stimuli presented in the visual angles 10°, 20°, and 30° in the UFOV task (r=.305, r=.322, and r=.299, respectively). However, it showed a negative correlation with the response time of the stimuli presented in the same location in the UFOV task (r=-.345, r=-.295, r=-.308). These results suggest that aging is associated with a decrease in the visuo-spatial attention allocation ability and perceptual bias toward positive and negative emotions. In addition, the positive and negative emotional perception biases associated with aging are potentially related to the reduced visuo-spatial attention allocation ability.