• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.1
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• pp.33-40
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• 1998

The composite SiO$_2$/Si$_3$N$_4$/SiO$_2$(ONO) film formed by oxidation on nitride film has been widely studied as DRAM stacked capacitor multi-dielectric films. Load lock(L/L) LPCVD system by HF cleaning is used to improve electrical capacitance and to scale down of effective thickness for memory device, but is brings a new problem. Nitride film deposited using HF cleaning shows selective deposition on poly silicon and oxide regions of capacitor. This problem is avoidable by carpeting chemical oxide using $H_2O$$_2$cleaning before nitride deposition. In this paper, we study the limit of nitride thickness for abnormal oxidation and the initial deposition time for nitride deposition dependent on underlayer materials. We proposed an advanced fabrication process for stacked capacitor in order to avoid selective deposition problem and show the usefulness of nitride deposition using L/L LPCVD system by $H_2O$$_2$cleaning. The natural oxide thickness on polysilicon monitor after HF and $H_2O$$_2$cleaning are measured 3~4$\AA$, respectively. Two substrate materials have the different initial nitride deposition times. The initial deposition time for polysilicon is nearly zero, but initial deposition time for oxide is about 60seconds. However the deposition rate is constant after initial deposition time. The limit of nitride thickness for abnormal oxidation under the HF and $H_2O$$_2$cleaning method are 60$\AA$, 48$\AA$, respectively. The results obtained in this study are useful for developing ultra thin nitride fabrication of ONO scaling and for avoiding abnormal oxidation in stacked capacitor application.

• Journal of KIISE:Software and Applications
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• v.29 no.9
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• pp.654-668
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• 2002

In this paper, we present an empirical study for improving the Korean text chunking based on machine learning and feature set selection approaches. We focus on two issues: the problem of selecting feature set for Korean chunking, and the problem of alleviating the data sparseness. To select a proper feature set, we use a heuristic method of searching through the space of feature sets using the estimated performance from a machine learning algorithm as a measure of "incremental usefulness" of a particular feature set. Besides, for smoothing the data sparseness, we suggest a method of using a general part-of-speech tag set and selective lexical information under the consideration of Korean language characteristics. Experimental results showed that chunk tags and lexical information within a given context window are important features and spacing unit information is less important than others, which are independent on the machine teaming techniques. Furthermore, using the selective lexical information gives not only a smoothing effect but also the reduction of the feature space than using all of lexical information. Korean text chunking based on the memory-based learning and the decision tree learning with the selected feature space showed the performance of precision/recall of 90.99%/92.52%, and 93.39%/93.41% respectively.

• PNF and Movement
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• v.11 no.2
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• pp.9-19
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• 2013

Purpose : Study on the effects of attention(working memory) for normal adults by applying transcranial Direct Current Stimulation(tDCS). Methods : There are two groups of 10 random people aged between 20 to 30, one is an experimental group(stimulation) and the other is a comparison group(simulate stimulation). For the 1st da y, pre-stimulation test is executed, and for the 2nd day to the 4th day, tDCS is applied stimulated both on the right prefrontal lobe and the left occipital lobe through the electrode. The stimulation lasts for 15 minutes with voltage power of 1mA for each day. The post-stimulation test is executed on the day of 5th. In this paper, a FAIR attention test is used for measuring the attention. Results : As the result of the experiment, there are significant gaps both on the value of P, the ability of selective attention, and the value of C, the consistent ability after the stimulation on right prefrontal and left occipital lobe. And there is no significant gap on the value Q, the quality(Control). However, all the P, Q, and C values are increased according to the average value between the pre-stimulation test and the post-stimulation. Conclusion : Finally, ability of selective attention and self-control, and consistent attention is progressed by applying the tDCS to the normal people.

• Korean Journal of Cognitive Science
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• v.18 no.2
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• pp.113-138
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• 2007

The effects of schema on accurate and false memories of items in a scene were investigated in two experiments: Recognition of items in a scene was tested immediately in Experiment 1 and three days later in Experiment 2. In both experiments, the following three variables were manipulated: Exposure time (250ms or 10000ms), picture mode (completed pictures or scrambled pictures), and manipulation mode (missing item or substituted item). Experiment 1 had yielded three important results: First, although accurate memory for presented items got increased when the exposure time was longer, false memory of the critical lures was not changed. Second, false memory of critical lures in the missing condition, where there was not any conflict between verbatim information and gist information, was higher than that of the substituted condition, where verbatim information of the item that replaced the lure was in conflict with the gist information. Third, accurate memory for atypical items in the substituted rendition, which had replaced the critical lures and in conflict with the schema, was higher than that in the missing condition. In Experiment 2, recognition test were administered 72 hours after the participants saw the picture. The three effects mentioned in Experiment 1 had disappeared in Experiment 2. The results of Experiment 2 might be due to the selective weakening of verbatim information compared to the persistence of the gist (or schematic) information. The results of Experiments 1 and 2 showed that false memory of critical lures is more persistent than the accurate memory of non-critical information. Theoretical implications of the results were considered in terms of the function of the verbatim and gist information.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2004.11a
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• pp.49-52
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• 2004

A few studies have shown that the function of fusiform face area is selectively involved in the perception of faces including a race difference. We investigated the neural substrates of the face-selective region called fusiform face area In the ventral occipital-temporal cortex and same-race memory superiority In the fusiform face area by the event-related fMRI. In our fMRI study, twelve healthy subjects (Oriental-Korean) performed the implicit distinction of the race while they consciously made familiar-judgments, regardless of whether they considered a face as Oriental-Korean or European-American. In the race distinction as an implicit task, the fusiform face areas (FFA) and the right parahippocampal gyrus had a greater response to the presentation of Oriental-Korean than European-American faces, but in the consciously race distinction between Oriental-Korean and European-American faces, any significant difference in the FFA was not observed. These results suggest that different activation in the fusiform regions and right parahippocampal gyrus resulting from same-race memory superiority could be implicitly taken place by the physiological processes of face recognition.

• BMB Reports
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• v.49 no.1
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• pp.1-2
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• 2016

Of the numerous events that occur in daily life, we readily remember salient information, but do not retain most less-salient events for a prolonged period. Although some of the episodes contain putatively emotional aspects, the information with lower saliency is rarely stored in neural circuits via an unknown mechanism. We provided substantial evidence indicating that synaptic plasticity in the dorsal ITC of amygdala allows for selective storage of salient emotional experiences, while it deters less-salient experience from entering long-term memory. After activation of D4R or weak fear conditioning, STDP stimulation induces LTD in the LA-ITC synapses. This form of LTD is dependent upon presynaptic D4R, and is likely to result from enhancement of GABA release. Both optogenetic abrogation of LTD and ablation of D4R at the dorsal ITC in vivo lead to heightened and over-generalized fear responses. Finally, we demonstrated that LTD was impaired at the dorsal ITC of PTSD model mice, which suggests that maladaptation of GABAergic signaling and the resultant LTD impairment contribute to the endophenotypes of PTSD. [BMB Reports 2016; 49(1): 1-2]

• Journal of Fashion Business
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• v.16 no.2
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• pp.124-137
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• 2012

This study aims to identify the meaning and formation cause of a style, and the essential elements of style formation, through psychobiological research as well as an analysis of the designs of Iris Van Herpen, a fashion designer, who in just 6 years has developed into a world-renowned new designer. As a result, it has been found that the psychobiological causes to form a style stem from the action of 'long-term memory', which is consolidated by 'selective attention', 'perceptional subjectivity', the principle of the 'neuron's connection specificity and invariance', and the principle of a 'neuronal signal's unilateral flow'. With such action, Herpen could develop her own original composition techniques. The formative shapes created by such composition techniques are characterized by enumeration, superposition, and hanging. The study has also found that the essential elements for a designer to be able to form his/her own style include 'aesthetic originality' in which the designer views the property of a thing from his/her inherent perspective, and finds the uniqueness from the thing that only he/she can express, 'technical differences' that are creative and original, and 'formative specificity' that is summarized into one property through an impressive shape.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.279-279
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• 2010

Smart gels have recently associated with photonic crystals to form photonic gels. Since these photonic gels are capable of reversibly converting the volume change of gels induced in response to external chemical or electric stimuli into characteristic optical signals, they have been considered not only as a good platform for label-free chemical or biological detection, actuators or optical switches but also as a good model system to investigate gel swelling behaviour. Recently, we reported block copolymer photonic gels self-assembled from polystyrene-b-poly(2-vinyl pyridine) (PS-b-P2VP) block copolymers, and demonstrated that selective swelling of lamellar structure allows extremely large tunability of the photonic stop band from UV region to IR region ($\lambda$ peak=350~1,600 nm). Herein we report block copolymer photonic gels which exhibit strong tunable optical hysteresis and their applications. As nonlinear responses in swelling of hydrogels were often observed, photonic gels exhibit optical hysteresis with change of external pH. We demonstrate such optical hysteresis can be precisely programmed by controlling ion-pairing affinity. We anticipate that photonic gels with carefully tunned optical hysteresis are applicable to optical memory devices.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.11
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• pp.1000-1009
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• 2013

This study investigated changes in behavioral performance before and after watching a multi-view 3D content by using auditory stimuli based on the selective attention theory in order to quantitatively evaluate 3D visual fatigue. Twenty-one undergraduates were asked to report on their current visual and physical condition both in the pre- and post-experiment. A selective attention task was conducted before and after mobile 3D viewing to compare the changes in performance. After performing a Wilcoxon's matched-pairs signed-ranks test on the subjective ratings of 3D visual fatigue, participants were categorized into two groups, unfatigued and fatigued group with a definite criterion. For the unfatigued group, no significant fatigue effects were found in behavioral response times and accuracies to specific auditory targets. In sharply contrast to the unfatigued group, the fatigued group showed significantly delayed response times and less response accuracies. However, no significant changes in accuracies for a working memory task were observed in both groups.

• Journal of IKEEE
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• v.24 no.1
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• pp.1-8
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• 2020

In this paper, a semi-infinite array analysis method is proposed to analyze the defects that may occur during the fabrication of the frequency selective radome. In the analysis of N×N finite array structure using 3D analysis software, much analysis time and memory are required, whereas the semi-infinite array structure analysis proposed in this paper can predict relatively accurate electromagnetic performance while reducing the analysis time. In comparison with the results of the periodic simulation, the simulation of the semi-infinite array structure confirmed the error within ±3%. To verify the results of the simulation, the results were compared with the measured results, and the same tendency at the point of performance change and similar performance degradation at the band of interest were investigated. Using the proposed semi infinite array structure analysis, it is confirmed that the analysis of defects in the electromagnetic periodic structure is possible.