• The KIPS Transactions:PartB
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• v.8B no.1
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• pp.105-113
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• 2001

최근 축약 분산 기억 장치(SDM)가 적응적 문제 해결 능력과 하드웨어화의 용이성으로 인해 현실성이 있는 신경망의 한 모델로 제안되었다. 그러나 다층 인식자의 개별 뉴런이 선형 또는 비선형 결정 함수로 해 공간을 이분하고 그들이 다양하게 결합함으로써 일반적인 문제 해결 능력을 갖는데 비해, 축약 분산 기억 장치의 뉴런은 해 공간에서 자신을 중심으로 한 일정 반경 영역을 안과 밖으로 이분하고 이들을 단순하게 합하므로써, 해 공간이 실수 공간과 같이 크기 관계를 갖는 경우 비효율적인 모델로 된다. 본 논문에서는 이러한 축약 분산 기억 장치의 특성과 그 원인을 규명하고, 문제의 해 공간이 단조 증가 또는 감소 결정 함수로 양분되는 경우, 기존의 축약 분산 기억 장치에 크기 비교 과정을 도입함으로써, 주어진 문제를 효율적으로 해결할 수 있는 수정된 축약 분산 기억 장치 모델을 제안한다. 아울러 제안된 모델을 ATM망에서의 호 수락 제어 과정에 적용한 예를 보인다.최근 축약 분산 기억 장치(SDM)가 적응적 문제 해결 능력과 하드웨어화의 용이성으로 인해 현실성이 있는 신경망의 한 모델로 제안되었다. 그러나 다층 인식자의 개별 뉴런이 선형 또는 비선형 결정 함수로 해 공간을 이분하고 그들이 다양하게 결합함으로써 일반적인 문제 해결 능력을 갖는데 비해, 축약 분산 기억 장치의 뉴런은 해 공간에서 자신을 중심으로 한 일정 반경 영역을 안과 밖으로 이분하고 이들을 단순하게 합하므로써, 해 공간이 실수 공간과 같이 크기 관계를 갖는 경우 비효율적인 모델로 된다. 본 논문에서는 이러한 축약 분산 기억 장치의 특성과 그 원인을 규명하고, 문제의 해 공간이 단조 증가 또는 감소 결정 함수로 양분되는 경우, 기존의 축약 분산 기억 장치에 크기 비교 과정을 도입함으로써, 주어진 문제를 효율적으로 해결할 수 있는 수정된 축약 분산 기억 장치 모델을 제안한다. 아울러 제안된 모델을 ATM망에서의 호 수락 제어 과정에 적용한 예를 보인다.

• Korean Journal of Cognitive Science
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• v.21 no.2
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• pp.359-386
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• 2010

In order to evaluate the domain-specific model and process-specific model of spatial and nonspatial working memory (WM), this study manipulated the memory load of the delayed response task and examined how the neural correlates of memory load effect was influenced by the stimulus domain (face and location) at the maintenance stage of WM using an event-related fMRI experiment. One or three face stimuli were presented as target stimuli and participants were asked to maintain the face itself (face WM) or the location of face stimuli (spatial WM). The results of recognition judgment accuracy showed no difference between face WM and spatial WM, and showed equivalent memory load effects of both WM. As a result of brian image analysis, memory load effect at maintenance stage showed that inferior, middle, and superior PFC were recruited by both face WM and spatial WM, and showed that VLPFC was the commonly activated area by both WM, supporting functional specialization of PFC by process components of WM. This study provides evidence for process-specific model in which maintenance of WM is associated with VLPFC.

• Korean Journal of Cognitive Science
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• v.16 no.3
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• pp.155-174
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• 2005

Oh and Kim (2004) and Woodman and Lurk (2004) demonstrated that spatial working memory (SWM) load Interfered concurrent visual search and that search process also impaired the maintenance of spatial information implying that visual search and SWM task both require access to the same limited-capacity mechanism. Two obvious possibilities have been suggested about what this shared limited-capacity mechanism is: common demand for attention to the locations where the items f9r the two tasks were presented (spatial attention load hypothesis), and common use of working memory to maintain a record of locations have been processed(SWM load hypothesis). To test these two hypothetical explanations, Experiment 1 replicated the mutual interference between visual search and SWM task in spite of difference of procedure with preceding researches; possible areas where the items for two tasks were presented were not separated. In Experiment 2, we presented the items for visual search either in the same quadrants where the items for SWM task had appeared (same-location rendition) or in the different quadrants (different-location condition). As a result, search efficiency was more impaired in the different-location condition than in the same-location condition. The memory accuracy was worse in the different-location rendition than in the same-location rendition. Overall results of study indicate that the mutual interference between SWM and visual search might be related to the overload of spatial attention, but not to that of SWM.

• Korean Journal of Cognitive Science
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• v.19 no.2
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• pp.125-142
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• 2008

This study investigated the effects of space- and object-based attention on spatial and visual working memory, by measuring recognition of working memory on the spatial Stroop task including two modalities of attention resource. The similarity condition of stimulus arrangement between working memory task and spatial stroop task was manipulated in order to examine the effects of space-based attention on spatial rehearsal during working memory task, while Stroop rendition was manipulated in order to examine the effects of object-based attention on object rehearsal during working memory task. The results showed that in a condition that stimulus arrangement was highly similar for the spatial working memory task and the spatial Stroop task, recognition accuracy of the spatial working memory was high, but it was not significantly different with the Stroop conditions. In contrast, the recognition accuracy of visual working memory in the incongruent Stroop condition was lower than that in the congruent Stroop condition, but it was not significantly different with the similarity conditions (25% vs. 75%). The results indicated that selective attention has effects on working memory only when resource modality of working memory is the same as that of selective attention.

• Korean Journal of Cognitive Science
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• v.10 no.4
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• pp.41-50
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• 1999

It is widely known that the hippocampus plays an important role in spatial memory. Recent studies have suggested that the posterior parietal cortex (PPC) is involved in spatial memory. However it is unclear whether the PPC is involved in w working memory or reference memory of spatial learning. The purpose of the present study was to determine contribution of the hippocampus and the PPC to spatial working memory and acquisition of reference memory. Using an eight-arm radial maze in which e each arm was baited. working memory was tested by measuring rat's ability to remember arms they had visited. Reference memory was tested by measuring rat's ability to avoid visiting four consistently unbaited arms. Effects of hippocampal or PPC lesion on working memory or acquisition of reference memory in radial-arm maze learning were investigated Working memory was impaired by hippocampal lesion whereas not affected by PPC lesion. Acquisition of reference memory was impaired by lesion in either site. The results suggest that the hippocampus plays an important role in the spatial working memory while both the hippocampus and the PPC contribute to the acquisition of spatial reference memory.

• The Journal of Korean society of community based occupational therapy
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• v.9 no.2
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• pp.13-22
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• 2019

Objective : The purpose of this technical research is to determine decline of episodic memory by normal aging focucing on object, spatial location, and temporal order memory. Methods : We allocated seventy-seven of healthy adults from twenty to eighty years old, and performed computer-based cognitive tasks which were consisted of the object, spatial location, and temporal order memory. We used OpenSesame(OpenSesame Inc, OR), put ten pictures people normally see in their daily life, and evaluated those aspects through asking the objects types, object spatial locations, and picture temporal orders from 10 sheets of the picture. Results : Object and spatial location memory were not affected by normal aging whereas, temporal order memory significantly decreased with normal aging. Specifically, temporal order memory for in their age of forty was significantly decreased compared with their age of twenty and object memory at their age of eighty was relatively high compared to spatial location and temporal order memory. We found out that temporal order memory worse fastest and object memory lasted longest. Conclusion : In this study, we confirmed characteristics of declines of episodic memory consisting of object, spatial location, and temporal order memory. Notably, we could specifically identify declines of spatial location and temporal order memory with normal aging previous studies investigated on a limited basis using conventional neuropsychological assessments. These findings would be helpful to screen impairment in episodic memory by normal aging and provide an evidence that cognitive intervention for healthy older adults needs to include spatial and temporal aspect of memory.

• Therapeutic Science for Rehabilitation
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• v.10 no.1
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• pp.105-114
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• 2021

Objective : The purpose of this study was to identify and compare the sex differences in episodic memory and spatial cognition in healthy young adults. Methods : Forty-eight undergraduates (male=24, female=24) were assessed for sex differences using the visual stimuli episodic memory task and the virtual reality-based spatial cognition task. The accuracy rates (%) for the What, Where, and When conditions of the episodic memory task and the average distance error (cm) for 10 trials of the spatial cognition task were analyzed. Results : There were no significant sex differences between the three conditions. The male participants showed a significantly higher performance on the spatial cognition task than the female participants Conclusion : The results of this study indicated that the sex differences in episodic memory could be altered by the test methods. Although episodic memory and spatial cognition mainly depend on the hippocampus, the sex-related differences between the two functions were inconsistent, suggesting that these two functions are independent.

• The Korean Journal of Archival Studies
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• no.40
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• pp.279-284
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• 2014

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.214-214
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• 2010

단위면적 당 메모리 집적도를 높이기 위해 플래시 기억소자의 크기를 줄일 때, 셀 사이의 거리의 감소에 의한 간섭효과가 매우 커져 소자 크기의 축소가 한계에 도달하고 있다. 이러한 문제점을 개선하기 위해 본 연구에서는 fringing field 효과를 이용한 SONOS 구조 게이트 위에 금속 공간층을 가지는 플래시 메모리 소자를 연구하였다. 소자에 소스와 드레인에 도핑을 하는 공정단계를 거치지 않아도 되는 fringing field 효과를 이용한 SONOS 구조를 가진 기억소자에서 트랩층 양 쪽에 절연막을 증착하고 게이트 외측으로부터 트랩층 양 쪽 절연막까지 금속을 증착시켜 금속 공간층을 형성하였다. 게이트에 전압을 인가할 때 트랩층 절연막 외측의 금속 공간층 영역에도 동시에 전압이 인가되므로 게이트가 스위칭 역할을 충분히 하게 하기 위해서 트랩층 양 쪽 절연막 두께를 블로킹 산화막 두께와 같게 하였다. 소자의 누설전류를 감소하기 위하여 채널 아래 부분에 boron으로 halo 도핑을 하였다. 제안한 기억소자가 fringing field 효과에 의해 동작하는 것을 확인하기 위하여 Sentaurus를 사용하여 제시한 SONOS 구조를 가진 기억소자의 전기적 특성을 조사하였다. 시뮬레이션을 통해 얻은 금속 공간층이 있을 때와 없을 때에 대한 각 상태에서 같은 조건으로 트랩층에 전하를 트랩 시켰을 때 포획된 전하량이 변하였다. 각 상태에서 제어게이트에 읽기 전압을 인가하여 전류-전압 특성 곡선을 얻었으며, 각 상태에서의 문턱전압의 변화를 통해 금속 공간층이 있을 때 간섭효과가 감소하였다.

• The Journal of the Korea Contents Association
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• v.22 no.8
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• pp.126-139
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• 2022

This study aims to present the criteria of location selection and contents composition of Sewol ferry memorial space from the perspective of placeness and dark tourism, one of the main concepts of cultural tourism theory, and to draw academic concepts and implications related to it. First, the location selection of Sewol ferry memorial space was proposed by applying the concept of placeness to each important location, and the direction of the contents composition was presented based on the contents components such as characters, stories, places and dark tourism composition directions. As a result, when the Sewol ferry memorial space is designed in use of systemizing the narrative structure of the storytelling method and implementing it specifically, it is suggested that it is possible to construct a Sewol ferry memorial space by distributing and course-making based on the narrative structure rather than focusing on the location selection of a specific place. In addition, it was argued that the contents composition criteria should be more complex and systematically established and applied considering the connection between placeness and dark tourism when the Sewol ferry memorial space is constructed in various sites like 416 life safety parks and Mokpo New Port. This study, which aims to answer research questions related to major issues based on the perspective of placeness and dark tourism on the Sewol ferry memorial space, is expected to be used as a reference for the construction of the memorial space in the future.