• Title/Summary/Keyword: Cognitive science

Search Result 3,791, Processing Time 0.029 seconds

Myricetin prevents sleep deprivation-induced cognitive impairment and neuroinflammation in rat brain via regulation of brain-derived neurotropic factor

  • Sur, Bongjun;Lee, Bombi
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.26 no.6
    • /
    • pp.415-425
    • /
    • 2022
  • Memory formation in the hippocampus is formed and maintained by circadian clock genes during sleep. Sleep deprivation (SD) can lead to memory impairment and neuroinflammation, and there remains no effective pharmacological treatment for these effects. Myricetin (MYR) is a common natural flavonoid that has various pharmacological activities. In this study, we investigated the effects of MYR on memory impairment, neuroinflammation, and neurotrophic factors in sleep-deprived rats. We analyzed SD-induced cognitive and spatial memory, as well as pro-inflammatory cytokine levels during SD. SD model rats were intraperitoneally injected with 10 and 20 mg/kg/day MYR for 14 days. MYR administration significantly ameliorated SD-induced cognitive and spatial memory deficits; it also attenuated the SD-induced inflammatory response associated with nuclear factor kappa B activation in the hippocampus. In addition, MYR enhanced the mRNA expression of brain-derived neurotropic factor (BDNF) in the hippocampus. Our results showed that MYR improved memory impairment by means of anti-inflammatory activity and appropriate regulation of BDNF expression. Our findings suggest that MYR is a potential functional ingredient that protects cognitive function from SD.

An Empirical Study on the Effect of Trust between Firms in the Supply Chain on Agility and Logistics Performance

  • Soohyo KIM;Changjoon LEE;Byoung Chun HA
    • Journal of Distribution Science
    • /
    • v.22 no.7
    • /
    • pp.95-106
    • /
    • 2024
  • Purpose: This study explores the effect on supply chain agility and logistics performance of building mutual trust between manufacturing companies that have adopted supply chain management. Previous studies have categorized trust into affective and cognitive types, and speed, flexibility, and responsiveness are recognized as subfactors of supply chain agility. Methodology: A survey gathered responses from employees of domestic manufacturing firms with supply chain management implementations. 254 valid responses underwent statistical analysis using structural equation modeling (SPSS 23.0 and AMOS 23.0). Results: Affective trust positively influences speed and responsiveness but not flexibility. Cognitive trust positively affects speed, flexibility, and responsiveness. Supply chain agility positively impacts logistics performance. However, neither affective nor cognitive trust significantly influences logistics performance. Conclusions: The study suggests that cognitive trust based on capabilities is more important than affective trust for flexibility in corporate relationships, a subfactor of supply chain agility. However, trust alone cannot enhance corporate performance. This research is significant as it examines the roles of trust and agility in the context of the COVID-19 pandemic, which has exacerbated the manufacturing business environment.

The Life Cycle of the Rendezvous Problem of Cognitive Radio Ad Hoc Networks: A Survey

  • Htike, Zaw;Hong, Choong Seon;Lee, Sungwon
    • Journal of Computing Science and Engineering
    • /
    • v.7 no.2
    • /
    • pp.81-88
    • /
    • 2013
  • In cognitive radio or dynamic spectrum access networks, a rendezvous represents meeting two or more users on a common channel, and negotiating to establish data communication. The rendezvous problem is one of the most challenging tasks in cognitive radio ad hoc networks. Generally, this problem is simplified by using two well-known mechanisms: the first uses a predefined common control channel, while the second employs a channel hopping procedure. Yet, these two mechanisms form a life cycle, when they simplify the rendezvous problem in cognitive radio networks. The main purpose of this paper is to point out how and why this cycle forms.

Artificial Intelligence Based Approaches to the Effect of Cognitive Style and Physiological Phenomena on Judgmental Time series forecasting: A Proposal

  • Park, Hung-Kook;Yoo, Hyeon-Joong;Byoungho Song
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
    • /
    • 2000.04a
    • /
    • pp.318-327
    • /
    • 2000
  • Managerial intuition is a well-recognized cognitive ability but still poorly understood for the purpose of developing effective decision support systems. this research investigates whether the differences in accuracy of "time series forecasting" are related to the differences in one's cognitive style, using statistical test The hypotheses established in the research model did not have positive correlation The lack of correlation between "cognitive style and physiological measures" and accuracy in forecasting may be caused by uncontrolled external variable. Thus, further analyses on physiological characteristics and brainwaves are needed. The approaches such as neural network and data mining are proposed.

  • PDF

Vicious Cycle of MAC Protocols of Cognitive Radio Ad Hoc Networks: Problem Statement

  • Htike, Zaw;Hong, Choong-Seon
    • Proceedings of the Korean Information Science Society Conference
    • /
    • 2012.06d
    • /
    • pp.294-296
    • /
    • 2012
  • In cognitive radio ad hoc networks, secondary users need to exchange control information before data transmission. This task is not trivial in cognitive radio networks due to the dynamic nature of environment. This problem is sometime called rendezvous problem of cognitive radio network. The rendezvous problem is normally tackled by using two famous approaches: the use of common control channel (CCC) and using channel hopping (a.k.a sequence-based protocols). However, these two famous solutions form a vicious cycle while solving the rendezvous problem. The main purpose of this paper is to point out how and why this vicious cycle is formed.

Joint Scheduling and Flow Control for Multi-hop Cognitive Radio Network with Spectrum Underlay

  • Quang, Nguyen Tran;Dang, Duc Ngoc Minh;Hong, Choong-Seon
    • Proceedings of the Korean Information Science Society Conference
    • /
    • 2012.06d
    • /
    • pp.297-299
    • /
    • 2012
  • In this paper, we introduce a joint flow control and scheduling algorithm for multi-hop cognitive radio networks with spectrum underlay. Our proposed algorithm maximizes the total utility of secondary users while stabilizing the cognitive radio network and still satisfies the total interference from secondary users to primary network is less than an accepted level. Based on Lyapunov optimization technique, we show that our scheme is arbitrarily close to the optimal.

An Integrated Game Theoretical Approach for Primary and Secondary Users Spectrum Sharing in Cognitive Radio Networks

  • Kim, Jong-Gyu;Nguyen, Khanh-Huy;Lee, Jung-Tae;Hwang, Won-Joo
    • Journal of Korea Multimedia Society
    • /
    • v.14 no.12
    • /
    • pp.1549-1558
    • /
    • 2011
  • In this paper, we address the problem of bandwidth sharing among multiple primary users and multiple secondary users in a cognitive radio network. In cognitive radio networks, effective spectrum assignment for primary and secondary users is a challenge due to the available broad range of radio frequency spectrum as well as the requisition of harmonious coexistence of both users. To handle this problem, firstly, Bertrand game model is used to analyze a spectrum pricing in which multiple primary users emulate with each other to acquire maximal profit. After that, we employ Cournot game to model the spectrum sharing of secondary users to obtain optimal profit for each user also. Simulation results show that our scheme obtains optimal solution at Nash equilibrium.

Dynamic Spectrum Allocation MAC Protocol based on Cognitive Radio for QoS Support (QoS 보장을 위한 Cognitive Radio 기반의 동적인 스펙트럼 할당 MAC 프로토콜)

  • Sun, Xianfeng;Joe, In-Whee
    • Proceedings of the Korean Information Science Society Conference
    • /
    • 2008.06d
    • /
    • pp.155-159
    • /
    • 2008
  • 비능률적인 스펙트럼 이용률과 제한적인 스펙트럼 밴드 사용의 문제점을 해결하기 위하여, Cognitive Radio가 중요한 솔루션으로써 많은 연구가 진행되고 있다. 본 논문에서는 다중 채널 무선 네트워크에서의 QoS 보장을 위하여 Cognitive Radio 기반의 동적인 스펙트럼 할당 (Dynamic Spectrum Allocation)을 이용한 새로운 MAC 프로토콜을 제안한다. 사용자의 요청에 따라서, 유동적인 스펙트럼은 DSA 메커니즘을 통한 QoS 보장을 위하여 할당 된다. 그리고 동적인 스펙트럼 할당 (DSA)은 컨트롤 채널의 FRQ/FRP/ACK-hello와 데이터 채널의 DATA/ACK에 의하여 동작한다. 스펙트럼 공유의 성능을 증가시키기 위한 협력 검출 (Cooperative Detection)을 위하여, MAC 프로토콜에서는 Hello 메시지가 주기적으로 교환된다. 추가적으로, 성능 평가를 통하여 본 논문에서 제안한 DSA-MAC이 IEEE 802.11 MAC에 비하여 높은 데이터 처리량을 보임을 증명했다.

  • PDF

Cognitive Behavioral Therapy of Paraphilia or Sexual Offenders (성도착증 혹은 성적 가해자의 인지행동치료)

  • Lim, Myung Ho;Yoo, Dong Soo;Lee, Jae Woo
    • Anxiety and mood
    • /
    • v.10 no.2
    • /
    • pp.85-94
    • /
    • 2014
  • Non-pharmacological treatments have long been used for paraphilia or sexual offenders, but few clinical studies were conducted. However, recently there were issued cognitive behavioral therapy of paraphilia or sexual offenders based on the research findings obtained so far. In addition, there were the changes of Diagnostic and Statistical Manual of Mental Disorder by American Psychiatric Association at 2014. The methods of cognitive behavioral therapy for paraphilia or sexual offenders were electric aversion therapy, olfactory aversion therapy, ammonia aversion therapy, covert sensitization, masturbatory reconditioning, directed masturbation, verbal satiation, social skill training, assertiveness training etc. By synthesizing the newly reported foreign guidelines for treatment and review articles, the aim of this study is to investigate the non-pharmacologic therapies used for treatment of paraphilia or sexual offenders.

A Study of Automotive IP Design based on the Driver's Cognitive Characteristics (운전자의 인지특성을 고려한 자동차 IP 설계에 관한 연구)

  • Kang, Seon-Mo;Paik, Seung-Youl;Park, Peom
    • Science of Emotion and Sensibility
    • /
    • v.1 no.2
    • /
    • pp.81-91
    • /
    • 1998
  • 운전자의 안전과 감성적 요구사항이 중요시 되는 차세대 자동차의 IP(Instrument Panel) 설계를 위해 운전자으 인지특성을 고려하였다. 오디어 유닛과 HVAC(Heat, Ventilation and Air Condition)등의 주요 IP 구성요소 설계에 중점을 두었으며, 운전자의 인지특성과 가장부합하는 형태의 IP를 도출하기 위해 인지실험을 실시하였다. 첫 번째로, 기존의 차량에 설계된 IP 궁성요소를 분석하였으며, 이를 바탕으로 버튼의 수와 배열, LCD패널의 위치등을 조합하여 총 16개의 IP 프로토타입을 제작하였다. 다음으로, 제작된 프로타입을 각각 0.2, 0.4, 0.6초의 간격으로 Tachisto scope를 이용하여 피실험자에게 제시한후, 인간의 인지 지도(Human cognitive Map)에 근거한 '그리가 방법(Drawing Method)'을 이용하여 그들의 단기기억(Short-term Memory)상의 정보를 주어진 답안지에 그리도록 하였다. 이 인지실험의 다구찌 분석을 통하여 운전자의 인지특성을 고려한 최적의 IP형태를 제시하였다.

  • PDF