• Title/Summary/Keyword: "The cat"

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Sensitivity and Acuity Trade-off in the Cat Visual System (고양이 시각신경계에서 보는 민감도-세감도의 균형)

  • Lee, Chun-Gil
    • Korean Journal of Cognitive Science
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    • v.8 no.4
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    • pp.11-18
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    • 1997
  • 야간 시각은 민감도를 극대화하고 주간 시각은 세감도를 극대화한다. 민감도와 세감도는 시각 기능의 두 목표이지만 상쇄적인 작용때문에 균형적인 선택이 요구된다. 민감도와 세감도를 결정하는 중요한 요인으로는 광학적인 요인과 신경학적인 요인이 있다. 망막의 지역적 분화는 바로 이러한 민감도-세감도 문제에서 기인하는데 망막의 2차원적인 제약이 시각신경계의 병행적인 경로와 이에 기초한 적응적 진화를 통해서 어느 정도 해소되는 듯이 보인다. 이 글은 야행-주행 습성을 동시에 갖추어 민감도와 세감도의 균형 문제가 각별히 부각되는 고양이의 초기 시각신경계에서 민감도와 세감도의 균형을 최적화하는 신경 기전을 소개한 것이다.

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Jumping Control of a Cat Robotic System by Model Transformation (모델변환에 의한 고양이 로봇 시스템의 점핑제어)

  • Suh, Jin-Ho;Yamakita, Masaki;Kim, Sang-Bong
    • Proceedings of the KIEE Conference
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    • 2002.07d
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    • pp.2427-2429
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    • 2002
  • 본 논문에서는, 지붕위로 뛰어오르기 위하여 벽의 반동을 이용하는 고양이의 운동상태를 흉내내어 수직의 방향으로 운동하는 고양이 로봇 시스템을 연구한다. 또한 이러한 로봇 시스템의 3-link 부분시스템의 운동은 slider-link에서 구속되어지고, 또한 singular자세를 쉽게 피할 수 있는 운동계획방법(motion planning method)을 제안한다. 제안되어진 연구결과는 수직동작에 대한 메카니즘에 유용한 방법이고 이론적 개념, 모델링, 그리고 제어를 논의한다. 마지막으로, 모의실험을 통한 결과로서 제안되어진 방법의 유용성을 설명한다.

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A Study of CAT Bond with Flood Risk (홍수위험의 대재해채권화에 관한 연구)

  • 신동호
    • Proceedings of the KAIS Fall Conference
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    • 2003.06a
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    • pp.146-149
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    • 2003
  • 본 연구에서는 대재해채권의 개념과 장단점, 필요성, 그리고 우리나라에서 발생가능성에 대해서 연구하였다. 우리나라도 급변하는 금융환경하에서 대재해채권과 같은 새로운 금융상품에 대해서 연구할 필요가 있다. 대재해채권은 보험시장과 자본시장의 상이한 요구조건을 동시에 충족시켜줄 수 있는 새로운 혁신적인 금융상품이다. 우리나라의 보험시장과 자본시장도 세계 시장의 조류에 발 맞추어 대재해채권에 대한 관심 및 투자가 필요한 시기이다.

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Antioxidant effect of flavonoid, myricetin with GSH, vitamin E, vitamin C on B16F10, murine melanoma cell

  • Yu, Ji-Sun;Kim, An-Keun
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.144.2-145
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    • 2003
  • Reactive Oxygen Species (ROS) are produced during normal cellular function. ROS are very transient species due to their high chemical reactivity that leads to lipid peroxidation and oxidation of some enzyme, massive protein oxidation and degradation. Under normal conditions, antioxidant are substances that either directly or indirectly protect cells against adverse effects of ROS. Several biologically important compounds have been reported to have antioxidant functions. These incluce vitamin C, vitamin E, GSH, flavonoids. superoxidee dismutase(SOD), glutathione peroxidase(GPX) and catalase(CAT). (omitted)

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영상처리를 이용한 이차원 형상측정

  • 김희식
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.10a
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    • pp.193-198
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    • 2001
  • 생산현장 업무에서는 측정검사업무의 비중이 크다. 측정검사의 업무는 품질향상을 위한 활동이며 또한 고부가가치의 제품을 위해서도 중요하다. 고품질 고정밀도는 철저한 측정검사를 통하여 이루어진다. 제품의 치수를 정확히 측정하여 정밀도 있는 부품을 제작하고 불량부품이나 파손된 부품을 검사하여 제거함으로써 제품의 성은과 품질이 우수하게 인정된다. 이러한 측정검사작업의 정밀도향상, 생산성 향상을 위해서는 자동화가 필요하다. 측정검사의 자동화 (CAT : Computer Aided Testing)에는 영상처리를 이용하는 시각검사의 자동화가 중요한 분야이다. 영상처리를 이용한 시각검사의 대상은 결함검사, 두께검사, 형상칫수 검사, 물체의 위치, 방향, 종류의 파악 등이 있다.

Role of the Cervical Sympathetics on the Submaxillary Reflex Secretion Evoked by Stimulation of the Afferent Glossopharyngeal Nerve of the Cat (가묘(家猫)에 있어서 설인신경중추단자극(舌咽神經中樞端刺戟)에 의한 반사성(反射性) 악하선분필(顎下腺分泌)에 미치는 경부교감신경(頸部交感神經)의 영향(影響))

  • Gill, Won-Sik;Park, Sah-Hoon
    • The Korean Journal of Physiology
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    • v.21 no.2
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    • pp.313-321
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    • 1987
  • To investigate whether the cervical sympathetics contains specific secretory fibers for the salivary glands, reflex salivation was evoked and the role of the sympathetics or the reflex was examined in ketamine-anesthetized cat. Stimulation of the central end of the glossopharyngeal nerve produced a copious secretion from the submaxillary gland and the response was not affected by the section of the cervical sympathetics or by the administration of phenoxybenzamine, whereas the response was abolished by severing the chorda tympani or by the administration of atropine. The salivary response was always associated with an increase in glandular blood flow. Both salivary and blood flow responses were decreased markedly by the superimposed stimulation of the cervical sympathetics or by the administration of norepinephrine. The decreased submaxillary blood flow always preceded the decrease in salivary flow on stimulation of the cervical sympathetics and the decreased blood flow recovered prior to the salivary flow upon cessation of the sympathetic stimulation. The inhibitory effects of the sympathetics and norepinephrine were completely abolished by the pretreatment with phenoxybenzamine. These results indicate that the glossopharyngeal nerve is one of the afferent limbs of the submaxillary salivary reflex and the chorda tympani is the only efferent limb of the reflex pathway. Thus, it is suggested that the cervical sympathetics does not contain the specific secretory fibers for the gland, but plays a role in inhibiting the reflex secretion by decreasing the blood flow to the gland.

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Experimental Studies on the Cardiovascular Effects of Haloperidol in Cat and Rabbit (Haloperidol 이 심혈관계에 미치는 영향)

  • Ahn, Young-Soo
    • The Korean Journal of Pharmacology
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    • v.11 no.2
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    • pp.19-27
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    • 1975
  • Haloperidol, a butyrophenone, was synthetized by Janssen and introduced for the treatment of psychosis. Although structurally different from the phenothiazines, the butyrophenones share many of their pharmacological properties, such as inhibition of conditioned avoidance response, blocking effect of amphetamine reaction, producing catalepsy, antishock effect and protection against the lethal effects of catecholalmines. Chlorpromazine can lower the arterial blood pressure through its adrenergic blocking activity, its direct effect in relaxing vascular smooth muscle, its direct effect in depressing the myocardium and its action in a complex manner on the central nervous system. In the case of haloperidol, however, was not clarified the mechanism of lowering the blood pressure. The present paper describes the effects of haloperidol on cardiovascular system to investigate the mechanisms of its actions on the arterial blood pressure. The results are followings; 1. In anesthetized cats, intravenous administration of haloperidol and chlorpromazine in the dose of 0.1mg/kg produced a slight decrease in the blood pressure, which followed by complete recovery within $30{\sim}60$ minutes. In the dose of 3mg/kg, however, both produced an abrupt and marked decrease of the blood pressure, which followed by delayed recovery. 2. Haloperidol in the dose ranges of 0.1mg to 3.0mg/kg tended to produce the heart rate slowing in the cats, while chlorpromazine has no effect on the rate. 3. Following administration of haloperidol or chlorpromazine, epinephrine reversal in the arterial blood pressure was observed in the cat, however the responses of norepinephrine and acetylcholine were little affected. 4. In the isolated rabbit atrium the contractility was depressed by haloperidol in the doses over 0.5mg per 100ml, but the rate was not affected. In contrast, the epinephrine-induced contractility was not depressed after haloperidol treatment. However, the increased rate of atrium by epinephrine was partially blocked after haloperidol. 5. In the isolated rabbit aortic strip, epinephrine-induced contraction was blocked by haloperidol. With the above results, it may be concluded that the hypotensive effect of haloperidol was largely due to ${\alpha}$-adrenergic blocking properties and the direct effect in depressing the myocardium as well as its action on central nervous system.

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