• 제목/요약/키워드: Memory function

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정신분열병 환자에서 인지기능 및 정신병적 증상의 상관관계 (Correlation between Cognitive Functions and Psychotic Symptoms in Schizophrenic Patients)

  • 김용구;이정애;이소연;이분희;한창수
    • 생물정신의학
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    • 제13권3호
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    • pp.191-201
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    • 2006
  • Objectives : The purpose of this study was to investigate whether the cognitive functions would be correlated with psychotic symptoms and whether antipsychotic treatments would affect the cognitive functions after 8 weeks. Methods : The thirty-five schizophrenic patients were conducted in this study. The psychopathology was measured using PANSS. The memory function, executive function, and sustained attention were measured using Memory Assessment Scale(MAS), Wisconsin Card Sorting Test(WCST), and Vigilance(VIG) and Cognitrone(COG) in Vienna Test System. After 8 weeks of antipsychotic treatment, we retested the cognitive tests. Results : 1) The cognitive tests after the 8 week's treatment showed significant improvements in memory and executive function in the schizophrenic patients. On the other side, sustained attention did not show improvement. 2) The change of PANSS were correlated with perseverative response, perseverative error and total correct in WCST at baseline. WCST scores at baseline were correlated with negative symptoms, but not positive ones. Conclusion : These study suggests that 1) the impaired sustained attention could be a vulnerability marker in schizophrenia, 2) memory & executive function deficit could be reversible after treatment, and 3) medication might have a benefit in improving the cognitive functions in schizophrenia. Furthermore, the data supports that the better premorbid executive function was, the more favorable was the treatment response in schizophrenic patients. Finally, this study indicates that executive function might be an index of treatment improvement.

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어플리케이션의 가상 메모리 보호를 위한 연구 (A Study for Protecting the Virtual Memory of Applications)

  • 김동율;문종섭
    • 대한임베디드공학회논문지
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    • 제11권6호
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    • pp.335-341
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    • 2016
  • As information technology advances rapidly, various smart devices are becoming an essential element in our lives. Smart devices are providing services to users through applications up on the operating system. Operating systems have a variety of rules, such as scheduling applications and controlling hardwares. Among those rules, it is significant to protect private information in the information-oriented society. Therefore, isolation task, that makes certain memory space separated for each application, should highly be guaranteed. However, modern operating system offers the function to access the memory space from other applications for the sake of debugging. If this ability is misused, private information can be leaked or modified. Even though the access authority to memory is strictly managed, there exist cases found exploited. In this paper, we analyze the problems of the function provided in the Android environment that is the most popular and opened operating system. Also, we discuss how to avoid such kind of problems and verify with experiments.

부유게이트 트랜지스터를 이용한 아날로그 연상메모리 설계 (Design of an Analog Content Addressable Memory Implemented with Floating Gate Treansistors)

  • 채용웅
    • 대한전기학회논문지:시스템및제어부문D
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    • 제50권2호
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    • pp.87-92
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    • 2001
  • This paper proposes a new content-addressable memory implemented with an analog array which has linear writing and erasing characteristics. The size of the array in this memory is $2{\times}2$, which is a reasonable structure for checking the disturbance of the unselected cells during programming. An intermediate voltage, Vmid, is used for preventing the interference during programming. The operation for reading in the memory is executed with an absolute differencing circuit and a winner-take-all (WTA) circuit suitable for a nearest-match function of a content-addressable memory. We simulate the function of the mechanism by means of Hspice with 1.2${\mu}m$ double poly CMOS parameters of MOSIS fabrication process.

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성인의 스마트폰 중독이 기억손상에 영향을 미치는 과정에서 집행기능결함의 매개효과 (The Effect of Adult Smartphone Addiction on Memory Impairment: Focusing on the Mediating effect of Executive Function Deficiencies)

  • 임지영
    • 디지털융복합연구
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    • 제16권7호
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    • pp.299-308
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    • 2018
  • 본 연구는 성인의 스마트폰 중독이 기억손상에 영향을 미치는 과정에서 집행기능결함의 매개효과를 검증하고 상담개입과정에서의 함의를 알아보기 위해 수행되었다. 성인 300명(남 146명, 여 154명)을 대상으로 스마트폰 중독 진단척도, 집행기능결함을 측정하기 위한 Barkley Deficits in Executive Functioning Scale-Short Form(BDEFS-SF), 기억손상을 측정하기 위한 다요인 기억설문지를 실시하였다. 분석결과는 다음과 같다. 첫째, 스마트폰 중독은 집행기능결함 및 기억손상과 정적 상관을 나타냈고, 집행기능결함은 기억손상과 정적 상관을 나타냈다. 둘째, 스마트폰 중독 위험집단은 일반사용자집단에 비해 집행기능결함과 기억손상의 모든 하위요인들에서 유의미하게 높은 점수를 나타냈다. 셋째, 스마트폰 중독과 집행기능결함의 하위요인들이 기억손상에 미치는 상대적 영향력을 파악하기 위해 단계적 회귀분석을 실시한 결과, 자기조직화/문제해결, 시간에 대한 자기관리, 자제, 금단의 순으로 기억손상에 대한 설명력을 나타냈다. 넷째, 집행기능결함은 스마트폰 중독과 기억손상 간의 관계에서 완전매개역할을 했다. 본 연구결과는 스마트폰 중독경향이 있는 성인을 위한 상담개입과정에서 인지기능 향상을 위한 집행기능 재활훈련 프로그램의 개발 필요성을 시사하였다.

Memory Effect of $In_2O_3$ Quantum Dots and Graphene in $SiO_2$ thin Film

  • Lee, Dong Uk;Sim, Seong Min;So, Joon Sub;Kim, Eun Kyu
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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    • pp.240.2-240.2
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    • 2013
  • The device scale of flash memory was confronted with quantum mechanical limitation. The next generation memory device will be required a break-through for the device scaling problem. Especially, graphene is one of important materials to overcome scaling and operation problem for the memory device, because ofthe high carrier mobility, the mechanicalflexibility, the one atomic layer thick and versatile chemistry. We demonstrate the hybrid memory consisted with the metal-oxide quantum dots and the mono-layered graphene which was transferred to $SiO_2$ (5 nm)/Si substrate. The 5-nm thick secondary $SiO_2$ layer was deposited on the mono-layered graphene by using ultra-high vacuum sputtering system which base pressure is about $1{\times}10^{-10}$ Torr. The $In_2O_3$ quantum dots were distributed on the secondary $SiO_2$2 layer after chemical reaction between deposited In layer and polyamic acid layer through soft baking at $125^{\circ}C$ for 30 min and curing process at $400^{\circ}C$ for 1 hr by using the furnace in $N_2$ ambient. The memory devices with the $In_2O_3$ quantum dots on graphene monolayer between $SiO_2$ thin films have demonstrated and evaluated for the application of next generation nonvolatile memory device. We will discuss the electrical properties to understating memory effect related with quantum mechanical transport between the $In_2O_3$ quantum dots and the Fermi level of graphene layer.

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Docosahexaenoic acid가 전기충격성 뇌장애 마우스의 기억력 및 Acetylcholine량 변화에 미치는 영향 (The Effect of Docosahexaenoic Acid on Brain Function and Acetylcholine Level in Cerebral Cortex of Electroconvulsive Shock Induced Mice)

  • 김문정;신정희;윤재순
    • 약학회지
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    • 제39권3호
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    • pp.231-242
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    • 1995
  • Electroconvulsive shock (ECS) increases the activity of acetylchohnesterase and decreases in brain acetylcholine levels. A large amount of free fatty acids accumulated in the brain tissue affects cerebral blood flow, brain edema and inflammation and results in brain injury. The present study examined the effect of docosahexaenoic acid (DHA) and D,L-pyroglutamic acid (D,L-PCA) on the learning and memory deficit using the passive avoidance failure technique and on the change of acetylcholine and choline level in the cerebral cortex of ECS-induced mice. The application of ECS (25mA, 0.5sec) induced a significant decrease in memory function for 30 min. ECS-induced a significant decrease in cortical acetylcholine and choline levels 1 min following the ECS application, which were almost recovered to ECS control level after 30 min. DHA (20 mg/kg, i.p.). administered 24 hr before shock. prevented the ECS-induced passive avoidance failure and the decrease of acetylcholine level 1 min following the ECS application. DHA failed to elicit a change in cortical choline level. DHA did not affect memory function and the cortical Ach and choline level of normal mice. The administration of D,L-PCA (500 mg/kg, i.p.) increased the effect of DHA on memory function and the change of cortical acetylcholine level of ECS induced mice. These results suggest that DHA treatment may be contributed to the prevention against memory deficit, and to the activation of cholinergic system in the ECS induced mice.

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다중 블록 지우기 기능을 적용한 퓨전 플래시 메모리의 FTL 성능 측정 도구 설계 및 구현 (Design and Implementation of FTL Performance Measurement Tool using Multi Block Erase of Fusion Flash Memory)

  • 이동환;조원희;김덕환
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2008년도 하계종합학술대회
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    • pp.647-648
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    • 2008
  • Traditional FTL and flash file systems based of NAND flash memory may not be adaptively applied to new fusion flash memory which combines the advantages of NAND and NOR flash memory. In this paper, we propose a FTL performance measurement tool using Multi Block Erase function of fusion flash memory. The performance measurement tool shows that multi block erase function can be effectively utilized in performance enhancement of garbage collection for fusion flash memory.

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초발 주요우울장애 환자의 우울 삽화 및 관해 상태에서 신경인지기능 결함 비교 (Comparison of Neuropsychological Deficits between Depressed Episode and Remission in First-onset Patients with Major Depressive Disorder)

  • 허지원;김용구
    • 생물정신의학
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    • 제15권2호
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    • pp.92-100
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    • 2008
  • Objectives : The purpose of this study was to investigate 1) the neuropsychological deficits with major depressive disorder(MDD) in depressed state and 2) the changes of neuropsychological dysfunctions during depressed episodes and remitted periods in the MDD group. Methods : 12 patients with MDD and 70 normal controls who were diagnosed and classified by DSM-IV and SCID-IV interview participated in this study. The psychopathology was measured using the Hamilton rating scale for depression(HAM-D) and Brief Psychiatric Rating Scale(BPRS). The memory function, executive function, and sustained attention were measured by a trained psychologist using the Korean version of Memory Assessment Scale(K-MAS), Wisconsin Card Sorting Test(WCST), and Vigilance(VIG) and Cognitrone (COG) in Vienna Test System. After 6 weeks of treatment, we retested the cognitive tests in order to measure the cognitive functions in remitted states. Results : Patients with MDD achieved significantly lower score in sentence immediately recall, verbal memory score and total memory score of the K-MAS, total errors of the WCST, response time of Vigilance and response time at "Yes" response of Cognitrone than normal controls at baseline. After 6 weeks of medication, the psychiatric symptoms in the patient group were attenuated, and most of the neuropsychological functions including attention, memory, and frontal/executive function were improved except for response time of Cognitrone. Conclusions : This study provides evidence for distinct neuropsychological deficits in patients with MDD on their depressed states and remitted periods. The impairment on response time remains after remission, and this would be a trait marker of major depressive disorder.

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CMAC 제어기를 위한 효과적인 메모리 매핑 함수 (An Effective Memory Mapping Function for CMAC Controller)

  • 권호열;변증남;서일홍
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1989년도 추계학술대회 논문집 학회본부
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    • pp.488-493
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    • 1989
  • In this paper, the structure of CMAC address mapping is first revisited, and the address hashing function and the random mapping is discussed in the conventional CMAC implementation. Then the effective size of CMAC memory is derived from the modulus property of the CMAC address vector, and a new hashing function for the effective memory mapping is proposed for a CMAC implementation with feasible memory size and no troublesome random mapping. Finally, the performance of the conventional CMAC learning algorithm and that of the proposed new CMAC scheme arc compared via simulations.

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경증 외상성 뇌손상 환자에서 신체적 증상, 우울, 불안과 인지기능의 관계 (Relations between Somatic Symptoms, Depression, Anxiety, and Cognitive Function in Patients with Mild Traumatic Brain Injury)

  • 김명헌;오상우;노승호
    • 생물정신의학
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    • 제15권3호
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    • pp.194-203
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    • 2008
  • Objectives : This study was aimed at evaluating the relationship between somatic symptoms, depression, anxiety and cognitive function in the patients with Mild Traumatic Brain Injury(MTBI). Methods : Thirty seven patients with MTBI were selected from those patients who had visited the Department of Neuropsychiatry of Wonkwang University Hospital from 2003 to 2007. To assess and quantify the somatic symptoms, depression and anxiety, Personality Assessment Inventory(PAI) was used. Assessment of cognitive function was carried out by using Korean Wechsler Adult Intelligence Scale(K-WAIS), Rey-Kim Memory Test, and Kims Executive Function Test. The effects of somatic symptoms, depression, and anxiety on the cognitive function were evaluated by Pearson correlation test. Results : Somatic symptoms, depression, and anxiety, all showed inverse correlation to cognitive function. Specifically, 1) an increase in somatic symptoms was associated with a decrease in attention, verbal short term memory, verbal recall and recognition, and visual memory. 2) An increase in anxiety was associated with a decrease in verbal recall and recognition. 3) An increase in depression was associated with a decrease in cognitive function that requires high attention and verbal memory. Conclusion : The patients with MTBI displayed diverse symptoms ranging from cognitive impairment to somatic symptoms, depression, and anxiety. Somatic and emotional symptoms were correlated with cognitive function(especially executive function). Importantly, this study raises the possibility of treating the cognitive impairment associated with MTBI by treating somatic symptoms, depression, and anxiety.

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