• Title/Summary/Keyword: Memory performance

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Verbal Memory Function and Characteristics of Memory Process in Schizophrenia and Affective Disorder (정신분열병과 기분장애 환자의 언어적 기억능력과 기억과정의 특성에 대한 연구)

  • Lee, So-Youn;Lee, Bun-Hee;Lee, Jung-Ae;Kim, Kye-Hyun;Kim, Yong-Ku;Park, Sun-Wha
    • Korean Journal of Biological Psychiatry
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    • v.12 no.2
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    • pp.207-215
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    • 2005
  • Objectives:This study was to compare verbal memory ability among patients with schizophrenia, bipolar manic patients and unipolar depressive patients, and to understand their charicteristics of memory process. Methods:All subjects were hospitalized patients and had been interviewed by using the Structured Clinical Interview for DSM-IV(SCID). Schizophrenic patients(N=40), bipolar manic patients(N=17), and unipolar depressive patients(N=20) were assessed with K-AVLT for verbal memory and with K-WAIS for verbal IQ. Three groups were compared regarding total immediate recall, delayed recall, delayed recognition, learning curve, memory retention, and retrieval efficiency under controlled verbal IQ. Multiple regression analysis was performed to find which clinical factors have an influence on verbal memory ability. Results:In MANCOVA, differences of verbal memory test scores among the groups were statistically significant(F=1.800, p<.05). In post hoc analysis, Patients with schizophrenia and bipolar mania showed poorer performance in immediate recall, delayed recall, delayed recognition, retrieval efficiency than unipolar depres- sive patients. And schizophrenics performed poorly in delayed recall, delayed recognition, retrieval efficiency than nonpsychotic affective disorder group, but no difference in total immediate recall, delayed recall, delayed recognition, retrieval efficiency between the schizophrenic group and the psychotic affective group. Conclusions:These results partially confirm previous reports of verbal memory ability among major psychiatric disorders. Our results showed that psychotic symptoms were related with verbal memory, and longer duration of illness was related with poorer performance in schizophrenia and unipolar depression.

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Implementation of External Memory Expansion Device for Large Image Processing (대규모 영상처리를 위한 외장 메모리 확장장치의 구현)

  • Choi, Yongseok;Lee, Hyejin
    • Journal of Broadcast Engineering
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    • v.23 no.5
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    • pp.606-613
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    • 2018
  • This study is concerned with implementing an external memory expansion device for large-scale image processing. It consists of an external memory adapter card with a PCI(Peripheral Component Interconnect) Express Gen3 x8 interface mounted on a graphics workstation for image processing and an external memory board with external DDR(Dual Data Rate) memory. The connection between the memory adapter card and the external memory board is made through the optical interface. In order to access the external memory, both Programmable I/O and DMA(Direct Memory Access) methods can be used to efficiently transmit and receive image data. We implemented the result of this study using the boards equipped with Altera Stratix V FPGA(Field Programmable Gate Array) and 40G optical transceiver and the test result shows 1.6GB/s bandwidth performance.. It can handle one channel of 4K UHD(Ultra High Density) image. We will continue our study in the future for showing bandwidth of 3GB/s or more.

A Fast Scalable Video Encoding Algorithm (고속 스케일러블 동영상 부호화 알고리듬)

  • Moon, Yong Ho
    • IEMEK Journal of Embedded Systems and Applications
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    • v.7 no.5
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    • pp.285-290
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    • 2012
  • In this paper, we propose a fast encoding algorithm for scalable video encoding without compromising coding performance. Through analysis on multiple motion estimation processes performed at the enhancement layer, we show redundant motion estimations and suggest the condition under which the redundant ones can efficiently be determined without additional memory. Based on the condition, the redundant motion estimation processes are excluded in the proposed algorithm. Simulation results show that the proposed algorithm is faster than the conventional fast encoding method without performance degradation and additional memory.

FLASH : A Main Memory Storage System

  • Kim, Pyung-Chul;Jung, Byung-Gwan;Kim, Moon-Ja
    • The Journal of Information Technology and Database
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    • v.1 no.2
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    • pp.103-125
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    • 1994
  • In this paper, we introduce a new main memory storage system called FLASH that is designed for real-time applications. The FLASH system is characterized by the memory residency of data and a new fast and dynamic hashing scheme called extendible chained bucket hashing. We compared the performance of the new hashing algorithm with other well-known ones. Also, we carried out an experiment to compare the overall performance of the FLASH system with a commercial one. Both comparison results show that the new hashing scheme and the FLASH system outperforms other competitives.

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A fully digitized Vector Control of PMSM using 80296SA (80296SA를 이용한 영구자석 동기전동기 벡터제어의 완전 디지털화)

  • 안영식;배정용;이홍희
    • Proceedings of the KIPE Conference
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    • 1998.11a
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    • pp.5-8
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    • 1998
  • The adaptation to vector control theory is so generalized that it is widely used for implementing the high-performance of AC machine. Nowadays, One-Chip microprocessors or DSP chips are being well-used to implement Vector Control algorithm. DSP Chip have less flexibility for memory decoding and I/O rather than One-Chip microprocessor so that is requires more additional circuit and high cost. And the past One-Chip micro processors have difficult of implementation the complex algorithm because of small memory capacity and low arithmetic performance. Therefore we implemented the vector control algorithm of PMSM(Permanent Magnetic Synchronous Motors) using 80296SA form intel , which have many features as 6M memory space, 500MHz clock frequency, including memory decoding circuit and general I/O, Special I/O(EPA, Interrupt controller, Timer/Count, PWM generator) which is proper controller for the complex algorithm or operation program requiring so much memory capacity, So in this paper we fully digitized the vector control of PMSM included SVPWM Voltage controller using the intel 80296SA

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Time-based Prospective Memory of Children : Effect of Reminder Type (기억유발자극이 아동의 시간의존적 미래계획 기억 발달에 미치는 영향)

  • Seo, Ji-Yeon;Choi, Kyoung-Sook
    • Korean Journal of Child Studies
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    • v.28 no.5
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    • pp.161-174
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    • 2007
  • To analyze the effect of reminder type on the development of time-based prospective memory of children, 270(90 each 5-, 7-, and 9-year old) participants were randomly divided by age group into three subgroups : self-cued reminder, other-cued reminder, and control groups. Results showed that the performance of time-based prospective memory significantly increased with age, and the presentation of reminders was effective for improving the performance of time-based prospective memory. For younger children the presentation of other-cued reminder was more effective than self-cued reminder, but for the older children, presentation of self-cued reminder was more effective than other-cued reminder.

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Efficient Use of On-chip Memory through Profile-Driven Array Reorganization

  • Cho, Doosan;Youn, Jonghee
    • IEMEK Journal of Embedded Systems and Applications
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    • v.6 no.6
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    • pp.345-359
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    • 2011
  • In high performance embedded systems, the use of multiple on-chip memories is an essential architectural feature for exploiting inherent parallelism in multimedia applications. This feature allows multiple data accesses to be executed in parallel. However, it remains difficult to effectively exploit of multiple on-chip memories. The successful use of this architecture strongly depends on how to efficiently detect and exploit memory parallelism in target applications. In this paper, we propose a technique based on a linear array access descriptor [1], which is generated from profiled data, to detect and exploit memory parallelism. The proposed technique tackles an array reorganization problem to maximize memory parallelism in multimedia applications. We present preliminary experiments applying the proposed technique onto a representative coarse grained reconfigurable array processor (CGRA) with multimedia kernel codes. Our experimental results demonstrate that our technique optimizes data placement by putting independent data on separate storage. The results exhibit 9.8% higher performance on average compared to the existing method.

Design of a Bias Circuit for Reducing Memory Effects (Memory Effect를 줄이기 위한 바이어스 회로의 설계)

  • Kang, Sanggee
    • Journal of Satellite, Information and Communications
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    • v.12 no.4
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    • pp.115-119
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    • 2017
  • Intermodulation distortion degrades the S/N(signal-to-noise) of the original signal and also affects the adjacent channels. Intermodulation distortion is mainly caused by the nonlinear characteristics of the power amplifier. If the power amplifier with nonlinear characteristics has a memory effect, the intermodulation distortions occurred in the power amplifier are generated in various and complex forms. The predistorter is used as a way to improve intermodulation distortions. In order to efficiently utilize the performance of the predistorter, the memory effect of the power amplifier must be reduced. In this paper, we describe the design method of bias circuit to reduce the memory effect in power amplifiers. To reduce the memory effect, the bias circuit must have a high impedance for the signal and a low impedance for the envelope(modulating signal) and the second harmonic component of the signal. To verify the performance of the bias circuit designed considering the memory effect, a power amplifier operating at 170 ~ 220MHz was designed and implemented. The designed bias circuit has a large impedance in the operating frequency band and low impedance in the envelope signal and the second harmonic of the signal. As a result of the performance measurement, it was found that the asymmetric intermodulation distortion component is improved by 3.7dB.

UI for Supporting Old Age's Prospective Memory (노인의 미래기억을 보조하는 UI)

  • Yoon, Yong-Sik;Sohn, Young-Woo
    • Journal of the HCI Society of Korea
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    • v.1 no.1
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    • pp.89-95
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    • 2006
  • Prospective memory is memory for activities to be performed in the future, such as remembering to purchase a piece of fruit on the way home or remembering to give someone a telephone message. Due to the decrease in memory ability, the aged have difficulty in remembering the tasks they intended to perform in the future. Employing survey and experimental methods, we identified the UI requirements for enhancing prospective memory (PM) performance for the aged. The survey included subjective assessments of PM performance for the aged and their preferred usability components and PM-supporting systems in an ubiquitous computing environment. The experiment examined the effect of contextual cues on PM performance for the young and the aged. Practical implications of our results were discussed in the respects of PM-supporting UI design requirements for the aged.

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A Study on the Factors of the Older Adults' Memory Performance (노인의 기억수행에 영향을 미치는 요인에 관한 연구)

  • Min, Hye-Sook
    • The Korean Journal of Rehabilitation Nursing
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    • v.3 no.2
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    • pp.181-195
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    • 2000
  • The purpose of this study is to find out the effects of personal characteristics, social support, depression, and metamemory on the older adults' memory performances. The subjects of the study consisted of 95 older adults over the age of 60 who are living in Busan. Some data were collected by means of the interview method, using questionnaires for metamemory (MIA questionnaire by Dixon, et al., 1988), and depression(GDS by Yesavage and Sheikl, 1986), social resoueces(Duke university, 1978), family support(Hyun-Sook Kang, 1985). The other data were collected by the testing method on the memory performance such as the immeadiate word recall task, the delayed word recall task, the word recognition task(Elderly Verbal Learning Test by Kyung Mi Choi, 1998), and the face recognition task(Face Recognition Task tool developed by Hye-Sook Min). The results of this study were as follows; 1. The level of metamemory is 3.4 points in the 5 point scale, the grades of the task and the achievement are relatively high and the grades of the change, the control, and the anxiety are relatively low in the sub-concepts. 2. Metamemory have significant relation with age(r=-.44), educational attainment(r=.46), depression(r=-.58), family support(r=.20), social resources(r=.20). 3. The significant variables to predict older adults' metamemory are educational attainment(22%), sex(11%), age (8.3%), depression(4.7%), and illness state(3%). 4. The strong variables to predict memory performances are metamemory, age, depression, social resources, educational attainment, illness state, and limitation of daily living activity related to illness. In conclusion, the enhancement strategies of metamemory and the social support and the prevention or reduction of depression are necessary to increase older adults' memory performances. Ultimately in this respect nurses' roles are very important in developing and performing some intervention programs for old adults' memory improvement, which have significant meanings in the field of nursing science.

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