• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.888-891
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• 2005

In this paper, the prototype of a walking guide robot with tactile display is introduced, and the psychophysical experiment of the tactile recognition for a tactile display is carried out and analyzed. The objective of this research is the development of a walking guide robot for the blind to walk safely. A walking guide robot consists of a guide vehicle and a tactile display device. A guide vehicle, located in the front of the walking blind, detects the obstacle using ultrasonic sensors and offers the information of position and walking direction acquired from GPS module to the walking blind by voice. The tactile display device, located in the handle which is connected with the guide vehicle by cane, offers the processed obstacle information such as position, size, moving, shape of obstacle and safe path, etc. The psychophysical experiments for the threshold of perception and recognition ability of tactile stimulation are carried out by the estimation of the subject group. As a result the appropriate tactile stimulus intensity and frequency to recognize tactile stimulation effectively are discussed and derived.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.38 no.6
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• pp.617-629
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• 2001

The mathematical models for the receptive field of simple cells in the human visual system have been developed in the areas of psychophysics, physiology and neuroscience. The various models used in the fields of digital image processing and computer vision include Gator complex, Gaussian derivatives and Hermite functions. In this paper, the effective widths for the models are derived based on the space-frequency uncertainty principle. The center frequency and parameters related to the models are determined in accordance with the human visual filters, and resultant bandwidths are analyzed. Furthermore, the characteristics of space and frequency for the models is analyzed and compared to the experimental data obtained from psychophysics.

• Journal of the Korean Society for information Management
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• v.20 no.2
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• pp.177-198
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• 2003

The most significant part of this study is in developing an experimental medel of user-friendly PDL. This study proposes both theoretical (conceptual) and physical (operational) models. The theoretical model includes the analysis on various factors and the realtionsips among factors which have a serious impacts on the design, building, and managing of PDL. And the physical model shows the shows the detailed structure and process which could be useful for both PDL designers and managers. Also provided is the images of major user interfaces, of which a PDL would be developed on the basis of the proposed medel in near future.

• Progress in Medical Physics
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• v.7 no.1
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• pp.37-52
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• 1996

Image-guided localized, water-suppressed in vivo $^1$H MR spectroscopic studies were performed on the patients with brain tumors, acute cerebral infarction and schizophrenia, and dogs. GE Signa 1.5 T whole-body MRI/MRS system using STEAM pulse sequence was used. Proton metabolite ratios relative to creatine (Cr) were obtained using a Marquart algorithm. In vivo $^1$H MR spectra in brain neoplastic tissues revealed the changes of signal intensities of N-acetylaspartate (NAA), choline (Cho) and lactate (Lac) resonances. The present results suggest that the observed metabolite alterations from localized, water-suppressed in vivo $^1$H MR spectroscopy can be useful as an index of brain tumors, cerebral infarction and schizophrenia, and provide good quality metabolic information of cerebral tissue in the field of thanato-chronology.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10a
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• pp.172-174
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• 2003

전자우편은 인터넷의 성장과 함께 필수적인 점보교환 수단으로 자리잡고 있다. 그 신속성과 용이성을 이용하여 많은 기업과 업체들이 손쉽게 광고 수단으로 이용하여 이로 인하여 개인과 기업에 큰 피해를 초래하고 있다. 필요한 스팸메일을 선정하여 분류하는데 개인과 조직에 많은 정신적 물리적인 스트레스를 요구한다. 본 논문에서는 통계적 학습 방법인 SVM을 이용하여 지속적으로 변화하는 다양한 스팸메일을 분류하고자 한다. 실험결과는 스팸메일 분류에 안정적인 성능을 보여줄 뿐 아니라 다양한 종류의 스팸메일을 카테고리별로 구분해 내는데 높은 성능을 보여준다.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.11
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• pp.943-949
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• 2005

For the psychophysical experiment of tactile perception of shapes, experimental system consists of vibrator, tactile stimulation array, measurement and control system is designed and prepared. The psychophysical experiment for the tactile perception of shape is carried out by the estimation of the subject group. Through the experiment the threshold of tactile perception to multi-stimuli with some line shape is obtained. Also the appropriate tactile stimulus intensity and frequency of the tactile stimulation array to recognize arbitrary shapes effectively are derived and discussed.

• The Korean Publising Journal, Monthly
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• s.253
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• pp.24-25
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• 1999

책은 무형의 지식과 정보를 담으면서 동시에 물리적인 형태를 지닌다. 정신과 물질을 동시에 갖춘 이 매력적인 형태의 책은, 그래서 예부터 예술적 심미의 대상이 돼왔다. 국내 판화가를 비롯한 예술가들이 책을 테마로 한 작품을 모아 전시한 '판화 예술 책'전이 지난 2월12일부터 12일간 서울 종로구 한국문화예술진흥원(원장 차범석) 미술관에서 열렸다. 김찬동(작가).임영길(홍익대 판화과 교수).고충환(미술평론가) 등이 기획을 맡고 50여 작가가 참여한 이번 전시회에는 오브제로서 책이 지니는 특성에 착안해 무한한 상상을 펼친 실험적인 작품들이 많이 선보였다. 책의 소재인 종이, 종이의 원료인 펄프와 수제종이에 주목하거나, 책이란 정보를 담아내는 그릇이란 점에 착안하며, 정보를 전달하는 운송기능에 초점을 맞추는 등 다양한 형식의 작품들이 눈길을 끌었다. 그 가운데 몇 작품을 소개한다.

• Science of Emotion and Sensibility
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• v.22 no.2
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• pp.37-48
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• 2019

Current research explores the effect of language on the perception of facial emotion as suggested by the psychological construction theory of emotion by using a psychophysical method. In this study, we hypothesize that the perception of facial expression may be influenced if the observer is shown an affective word before he/she judges an expression. Moreover, we suggest that his/her understanding of a facial emotion will be in line with the conceptual context that the word denotes. During the two experiments conducted for this project, a control stimulus or words representing either angry or happy emotions were briefly presented to participants before they were shown a target face. These target faces were randomly selected from seven faces that were gradually morphed to show neutral to angry (in Experiment 1) and neutral to happy (in Experiment 2) expressions. The participants were asked to perform a two-alternative forced choice (2AFC) task to judge the emotion of the target face (i.e., decide whether it is angry or neutral, or happy or neutral). The results of Experiment 1 (when compared with the control condition) showed that words denoting anger decreased the point of subjective equality (PSE) for judging the emotion of the target as anger, whereas words denoting happiness increased the PSE. Experiment 2, in which participants had to judge expressions on a scale from happy to neutral, produced a contrasting pattern of results. The outcomes of this study support the claim of the psychological construction theory of emotion that the perception of facial emotion is an active construction process that may be influenced by information (such as affective words) that provide conceptual context.

• Science of Emotion and Sensibility
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• v.18 no.1
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• pp.39-48
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• 2015

It is known that P300-based concealed information test (P300 CIT) was not greatly affected by the traditional countermeasures. This study was to test whether P300 CIT is affected by the new countermeasures. We used three types of countermeasures. First type was a sequential countermeasure in which participants had to respond in alternating ways to irrelevants by pressing the left index finger covertly when the encountered irrelevant firstly, by wiggling the right big toe inside the shoe when encountered irrelevant secondly, by imaging his or her mother's name when encountered irrelevant thirdly, and by imaging his or her father's name when encountered irrelevant fourthly until all stimuli were presented. Second type was a partial matching and physical countermeasure. Participants in this type were asked to press the left index finger imperceptibly after one of the irrelevants and wiggle the right big toe after another of the irrelevants. Third type was a partial matching and mental countermeasure. Participants were required to imagine mother's name for one irrelevant and father's name for another irrelevant. The results showed that contrary to our expectation, the use of sequential countermeasure increased the detection rate from 77% to 92%. The partial matching countermeasure had a negative effect on P300 CIT. The physical countermeasure decreased the detection rate from 77% to 46%, and the mental countermeasure decreased the detection rate from 100% to 69%. The necessity for the development of methods to prevent or detect countermeasure is discussed.

• Journal of Educational Research in Mathematics
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• v.23 no.1
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• pp.53-74
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• 2013

The purpose of this paper is to analyze how mathematically gifted middle school students find out the necessary and sufficient condition for a certain hyperbolic line to be parallel to a given hyperbolic line in Non-Euclidean disc model (Poincar$\acute{e}$ disc model) using the Geometer's Sketchpad. We also investigated their characteristic of mathematical thinking and analyze how they express what they had observed while they did mental experiments in the Poincar$\acute{e}$ disc using computer-aided construction tools, measurement tools and inductive reasoning.