• 제목/요약/키워드: cognitive mechanism

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유아 언어학습에 대한 하이퍼망 메모리 기반 모델 (Hypernetwork Memory-Based Model for Infant's Language Learning)

  • 이지훈;이은석;장병탁
    • 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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    • 제15권12호
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    • pp.983-987
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    • 2009
  • 유아들의 언어습득에 있어서 중요한 점 하나는 학습자에 대한 언어환경의 노출이다. 유아가 접하는 언어환경은 부모와 같은 인간뿐만 아니라 각종 미디어와 같은 인공적 환경도 포함되며, 유아는 이러한 방대한 언어환경을 탐색하면서 언어를 학습한다. 본 연구는 대용량의 언어 데이터 노출이 영향을 미치는 유아언어학습을 유연하고 적절하게 모사하는 인지적 기제에 따른 기계학습 방식을 제안한다. 유아의 초기 언어학습은 문장수준의 학습과 생성 같은 행동들이 수반되는데, 이는 언어 코퍼스에 대한 노출만으로 모사가 가능하다. 모사의 핵심은 언어 하이퍼망 구조를 가진 기억기반 학습모델이다. 언어 하이퍼망은 언어구성 요소들 간의 상위차원 관계 표상을 가능케 함으로써 새로운 데이터 스트림에 대해 유사구조의 적용과 이용을 도모하여 발달적이고 점진적인 학습을 모사한다. 본 연구에서는 11 개의 유아용 비디오로부터 추출한 문장 32744개를 언어 하이퍼망을 통한 점진적 학습을 수행하여 문장을 생성해 유아의 점진적, 발달적 학습을 모사하였다.

다자간 협동 공학설계를 위한 DCWA 시스템의 설계 및 구현 (Design and Implementation of Distributed Collaborative Writing System for Engineering Design Process)

  • 이병걸
    • 한국멀티미디어학회논문지
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    • 제3권1호
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    • pp.63-76
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    • 2000
  • 기존의 CSCW (Computer Supported Collaborative Work) 시스템은 단순히 문서나 메시지를 구성하고 전달하는 기능만을 지원할 뿐 협동 작업자들간의 조직구성, 업무분할 및 통합, 작업흐름 제어와 같은 인지학적 기능등은 효과적으로 반영하지 못하고 있다. 본 연구는 협동작업환경에서의 CAD(Computer Aided Design)/CASE(Computer Aided Software Engineering)와 같은 공학 디자인 프로세스를 인지학적으로 지원하기 위한 CSCW 시스템을 개발하는 데 그 목적이 있다. 제안된 DCWA (Distributed Collaborative Writing Aid) 시스템은 CAD/CASE 및 시뮬레이션 기능을 하나의 시스템으로 통합함으로써 조직구성, 업무분할, 작업흐름제어가 이들 기능에 통일적으로 적용될 수 잇도록 하였다. 특히 CAD 도구에서는 다중 사용자들 소유의 그림객체 간의 바인딩, 어태치먼트, 스케일링 기능들은 제공하여 결합 형태 및 정도를 나타내는 관계성 표현이 가능하도록 함으로써 업무분할 및 병합이 CAD 도구에서도 명확히 드러나도록 하였고, CASE 도구에서는 소프트웨어 시뮬레이션 기능과 연계하여 작업흐름 제어가 용이하도록 하였다. 이는 또한 제품을 생산하기 전에 미리 모형을 시뮬레이션 해봄으로써 제품 개발의 시간과 비용을 단축할 수 있는 효과를 가져다 준다.

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A Computational Model of the Temperature-dependent Changes in Firing Patterns in Aplysia Neurons

  • Hyun, Nam-Gyu;Hyun, Kwang-Ho;Hyun, Kwang-Beom;Han, Jin-Hee;Lee, Kyung-Min;Kaang, Bong-Kiun
    • The Korean Journal of Physiology and Pharmacology
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    • 제15권6호
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    • pp.371-382
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    • 2011
  • We performed experiments using Aplysia neurons to identify the mechanism underlying the changes in the firing patterns in response to temperature changes. When the temperature was gradually increased from $11^{\circ}C$ to $31^{\circ}C$ the firing patterns changed sequentially from the silent state to beating, doublets, beating-chaos, bursting-chaos, square-wave bursting, and bursting-oscillation patterns. When the temperature was decreased over the same temperature range, these sequential changes in the firing patterns reappeared in reverse order. To simulate this entire range of spiking patterns we modified nonlinear differential equations that Chay and Lee made using temperature-dependent scaling factors. To refine the equations, we also analyzed the spike pattern changes in the presence of potassium channel blockers. Based on the solutions of these equations and potassium channel blocker experiments, we found that, as temperature increases, the maximum value of the potassium channel relaxation time constant, ${\tau}_n(t)$ increases, but the maximum value of the probabilities of openings for activation of the potassium channels, n(t) decreases. Accordingly, the voltage-dependent potassium current is likely to play a leading role in the temperature-dependent changes in the firing patterns in Aplysia neurons.

정신치료와 신경생물학적 연구결과의 관계 (The Relationship between Psychotherapy and Neurobiological Findings)

  • 오현영;박용천
    • 생물정신의학
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    • 제19권1호
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    • pp.1-8
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    • 2012
  • The mechanism of psychotherapy is explained by the recent developments in neuroscience and neuroimaging. The purpose of this study is to understand the nature of psychotherapy and to discuss the future of psychotherapy improvement with the help of advances of the neurobiological findings in psychotherapy. For this study, we investigated a wide range of materials. We searched for various researches on psychotherapy, brain, and neurobiology. In addition to the conventional psychodynamic psychotherapy, we investigated research findings on cognitive behavioral therapy, interpersonal psychotherapy and eye movement desensitization and reprocessing (EMDR). Moreover, based on the actual experiences of treating patients, we speculated the neurobiological mechanisms of the process and results of psychotherapy. With the development of neuroscience, we are now able to understand the personal consciousness, unconsciousness and developmental process. Also subdividing the disease is made possible. Personalized treatment has become available, and we are able to predict the prognosis of patients. Our memories are composed by implicit memory and explicit memory. By psychotherapy, we can consciously remember explicit memory, and it becomes easier to explore implicit memory through free association. Through psychotherapy, we will also be able to learn the effect of acquired environment and experience. Psychotherapy is able to correct human behaviors by modifying the memories. Through the regulation of emotions, it becomes possible to modify the memories and correct the behaviors. In this process, doctor-patient relationship is the main factor which cause positive treatment effects. Furthermore imagination therapy or unconscious, non-verbal stimuli could bring about positive treatment effects. Now psychotherapy could be explained and studied by neuroscientific researches. In this sense, we could provide the direction of future advances in neuroscience by the neurobiological understanding of psychotherapy.

정지환(定志丸)의 기억 및 인지기능 향상에 대한 효능 연구 (Therapeutic Potential of Jeongjihwan for the Prevention and Treatment of Amnesia)

  • 정태영;정원춘;박종현
    • 동의생리병리학회지
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    • 제25권1호
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    • pp.37-47
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    • 2011
  • This study was aimed to investigate the memory enhancing effect of Jeongjihwan against scopolamine-induced amnesia in C57BL/6 mice. To determine the effect of Jeongjihwan on the memory and cognitive function, we have injected scopolamine (1 mg/kg, i.p.) into C57BL/6 mice 30 min before beginning of behavior tests. We have conducted Y-maze, Morris water-maze, passive avoidance and fear conditioning tests to compare learning and memory functions. Scopolamine-induced behavior changes of memory impairment were significantly restored by oral administration of Jeongjihwan (100 or 200 mg/kg/day). To elucidate the molecular mechanism underlying the memory enhancing effect of Jeongjihwan, we have examined the antioxidant defense system and neurotrophic factors. Jeongjihwan treatment attenuated intracellular accumulation of reactive oxygen species and up-regulated mRNA and protein expression of antioxidant enzymes as assessed by RT-PCR and western blot analysis, respectively. Jeongjihwan also increased protein levels of brain-derived neurotrophic factor (BDNF) compared with those in the scopolamine-treated group. Furthermore, as an upstream regulator, the activation of cAMP response element-binding protein (CREB) via phosphorylation was assessed by Western blot analysis. Jeongjihwan elevated the phosphorylation of CREB (p-CREB), which seemed to be mediated partly by extracellular signal-regulated kinase1/2 (ERK1/2) and protein kinase B/Akt. These findings suggest that Jeongjihwan may have preventive and therapeutic potential in the management of amnesia.

Paroxetine이 공황장애 환자의 증상 개선과 HRV 양상 변화에 미치는 영향 (The Effect of Paroxetine on Symptom Improvement and Change of Heart Rate Variability of the Patients with Panic Disorder)

  • 안주연;유범희
    • 대한불안의학회지
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    • 제2권2호
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    • pp.101-107
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    • 2006
  • Object : Since autonomic nerve system dysfunction was known as the mechanism of panic disorder, many researchers used heart rate variability (HRV) as means of measuring autonomic nerve function of patients with panic disorder. We aimed to examine the effect of paroxetine medication for 3 months on symptom improvement and change of heart rate variability of the patients with panic disorder. Methods : The subjects were patients with panic disorder who visited the psychiatric outpatient clinic of Samsung Medical Center in Seoul. We included panic disorder patients who were aged from 20 to 50 and in normal BMI range (from 18 to 30) to minimize the effect of age and weight on HRV data. We excluded the patients with EKG abnormalities, hypertension or other major psychiatric disorders. They took 20-40 mg paroxetine medication a day for 3 months. Alprazolam was used only during the first month to control the acute panic symptoms and was tapered off after that. We measured the acute panic inventory (API), Hamilton rating scale for anxiety and depression (HAM-A & HAM-D), Spielberger state-trait anxiety inventory (STAIS, STAIT), and Beck depression inventory (BDI) in order to assess clinical improvement of the patients. And we measured time and frequency domain HRV in the resting, standing and cognitive stress states to assess the change of HRV. All measurements were done before and after paroxetine treatment. Result : After paroxetine medication, patients showed significant improvement in all psychiatric scales. In time domain of HRV, standard deviations of all R-R intervals (SDNN) were significantly increased in all states. In frequency domain of HRV, the ratio of high frequency to total power (HF/TP) in the standing state was significantly increased. Conclusion : After 3 months paroxetine medication, panic disorder patients showed significant clinical improvement and change in HRV data such as SDNN in all states and HF/TP ratio in the standing state. This result suggests that paroxetine medication is effective for the improvement of autonomic nerve system dysfunction in panic disorder patients.

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스트레스 관리 시 호흡치료의 이론적 근거와 기법 적용 (Theoretical Bases and Technical Application of Breathing Therapy in Stress Management)

  • 이평숙
    • 대한간호학회지
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    • 제29권6호
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    • pp.1304-1313
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    • 1999
  • Breathing is essential for life and at the same time takes a role as a antidote for stress. In the Orient, it was recognized early that respiration, mind, and body have a relation that is inseparable and therefore proper breathing is so important. However, since the mechanism of therapeutic effect by breathing have not been verified, the treatment has been continued till recent years. From that which originated in the Orient, several techniques in the west have been developed to regulate breathing, and have been applying to the clinical situation and to studies, however scientific studies are still lacking. Recently, relaxed breathing has been used as an efficient strategy for breathing therapy as it has an effect on reducing physiological tension and arousal, and, therefore can be used as a basic technique to control or manage stress. In this study, in order to provide basic information and guidelines for clinical application, which will aid in the application of the theoretical basics of breathing therapy and its technique, a review of the literative was conducted. The findings are as follows: 1. Since proper breathing not only has, physically, the important function in supplying oxygen to the body but also gives a good emotional, or pleasant state of mind, it is the first step in controlling physical and mental health. 2. The basic types of breathing can be classified into two types; ‘diaphragmatic breathing(relaxed breathing)’ and ‘chest breathing(stress breathing)’. In yoga type breathing, there are four kinds of breathing, ‘upper breathing’, ‘mid breathing’, ‘down breathing’, and ‘complete breathing’. 3. The theoretical explanation of the positive thera peutic effect of breathing therapy techniques exemplifies good brain function, sufficient air flow through the nasal passages, diaphragmatic movement, light vagal stimulation, CO2 changes and cognitive diversion but in most studies, the hypothesis of CO2 is supported. 4. The technique of breathing is designated with many names according to the muscles and techniques used for breathing, and for control of stress, diaphragmatic breathing(relaxed breathing) is explained as a basic technique best used to manage of stress. 5. The relaxed-breathing includes slow diaphragmatic breathing, breath meditation, nasal breathing, yogic abdominal breathing, Benson's relaxed response, and quiet response.

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Depletion of Inositol Polyphosphate 4-Phosphatase II Suppresses Callosal Axon Formation in the Developing Mice

  • Ji, Liting;Kim, Nam-Ho;Huh, Sung-Oh;Rhee, Hae Jin
    • Molecules and Cells
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    • 제39권6호
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    • pp.501-507
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    • 2016
  • The corpus callosum is a bundle of nerve fibers that connects the two cerebral hemispheres and is essential for coordinated transmission of information between them. Disruption of early stages of callosal development can cause agenesis of the corpus callosum (AgCC), including both complete and partial callosal absence, causing mild to severe cognitive impairment. Despite extensive studies, the etiology of AgCC remains to be clarified due to the complicated mechanism involved in generating AgCC. The biological function of PI3K signaling including phosphatidylinositol-3,4,5-trisphosphate is well established in diverse biochemical processes including axon and dendrite morphogenesis, but the function of the closely related phosphatidylinositol-3,4,-bisphosphate (PI(3,4)P2) signaling, particularly in the nervous system, is largely unknown. Here, we provide the first report on the role of inositol polyphosphate 4-phosphatase II (INPP4B), a PI(3,4)P2 metabolizing 4-phosphatase in the regulation of callosal axon formation. Depleting INPP4B by in utero electroporation suppressed medially directed callosal axon formation. Moreover, depletion of INPP4B significantly attenuated formation of Satb2-positive pyramidal neurons and axon polarization in cortical neurons during cortical development. Taken together, these data suggest that INPP4B plays a role in the regulating callosal axon formation by controlling axon polarization and the Satb2-positive pyramidal neuron population. Dysregulation of INPP4B during cortical development may be implicated in the generation of partial AgCC.

Apolipoprotein E in Synaptic Plasticity and Alzheimer's Disease: Potential Cellular and Molecular Mechanisms

  • Kim, Jaekwang;Yoon, Hyejin;Basak, Jacob;Kim, Jungsu
    • Molecules and Cells
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    • 제37권11호
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    • pp.767-776
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    • 2014
  • Alzheimer's disease (AD) is clinically characterized with progressive memory loss and cognitive decline. Synaptic dysfunction is an early pathological feature that occurs prior to neurodegeneration and memory dysfunction. Mounting evidence suggests that aggregation of amyloid-${\alpha}$ ($A{\alpha}$) and hyperphosphorylated tau leads to synaptic deficits and neurodegeneration, thereby to memory loss. Among the established genetic risk factors for AD, the ${\varepsilon}4$ allele of apolipoprotein E (APOE) is the strongest genetic risk factor. We and others previously demonstrated that apoE regulates $A{\alpha}$ aggregation and clearance in an isoform-dependent manner. While the effect of apoE on $A{\alpha}$ may explain how apoE isoforms differentially affect AD pathogenesis, there are also other underexplored pathogenic mechanisms. They include differential effects of apoE on cerebral energy metabolism, neuroinflammation, neurovascular function, neurogenesis, and synaptic plasticity. ApoE is a major carrier of cholesterols that are required for neuronal activity and injury repair in the brain. Although there are a few conflicting findings and the underlying mechanism is still unclear, several lines of studies demonstrated that apoE4 leads to synaptic deficits and impairment in long-term potentiation, memory and cognition. In this review, we summarize current understanding of apoE function in the brain, with a particular emphasis on its role in synaptic plasticity and the underlying cellular and molecular mechanisms, involving low-density lipoprotein receptor-related protein 1 (LRP1), syndecan, and LRP8/ApoER2.

Match Field based Algorithm Selection Approach in Hybrid SDN and PCE Based Optical Networks

  • Selvaraj, P.;Nagarajan, V.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제12권12호
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    • pp.5723-5743
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    • 2018
  • The evolving internet-based services demand high-speed data transmission in conjunction with scalability. The next generation optical network has to exploit artificial intelligence and cognitive techniques to cope with the emerging requirements. This work proposes a novel way to solve the dynamic provisioning problem in optical network. The provisioning in optical network involves the computation of routes and the reservation of wavelenghs (Routing and Wavelength assignment-RWA). This is an extensively studied multi-objective optimization problem and its complexity is known to be NP-Complete. As the exact algorithms incurs more running time, the heuristic based approaches have been widely preferred to solve this problem. Recently the software-defined networking has impacted the way the optical pipes are configured and monitored. This work proposes the dynamic selection of path computation algorithms in response to the changing service requirements and network scenarios. A software-defined controller mechanism with a novel packet matching feature was proposed to dynamically match the traffic demands with the appropriate algorithm. A software-defined controller with Path Computation Element-PCE was created in the ONOS tool. A simulation study was performed with the case study of dynamic path establishment in ONOS-Open Network Operating System based software defined controller environment. A java based NOX controller was configured with a parent path computation element. The child path computation elements were configured with different path computation algorithms under the control of the parent path computation element. The use case of dynamic bulk path creation was considered. The algorithm selection method is compared with the existing single algorithm based method and the results are analyzed.