• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
• /
• pp.236-239
• /
• 1995

It is useful to simulate the human visual function for the purpose of image-processing. In this study, the hardware of the spatial filter with the sensitivity of lateral inhibition is realized by the combination of optical parts with electronic circuits. The diffused film with the characteristics of Gaussian type is prepared as a spatial filter. An object's image is convoluted with the spatial filter. From the difference of the convoluted images, the zero-cross position is detected at video rate. The edge of object is extracted in real-time by the use of this equipment. The resolution of edge changes with the value of the standard deviation of diffused film. In addition, it is possible to extract a directional edge selectively when the spatial filter with directional selectivity is used instead of Gaussian type of spatial filter.

• The Korean Journal of Physiology
• /
• 제21권1호
• /
• pp.91-101
• /
• 1987

The present experiment was carried out, in the rabbit and cat, in order to explore functional interrelationship between the vestibular semicircular canals and extraocular muscles, which are involved in the vestibulooculomotor reflex as the receptor and effector organ respectively. Semicircular canals were subjected to electrical stimulation, lymphatic fluid flow or acute freezing, and responses of the extraocular muscles were recorded in terms of changes in electromyographic activity and isometric tension. Electrical stimulation of a unilateral canal elicited contraction of the superio-medial muscle group (superior oblique, superior rectus and medial rectus muscles) in the ipsilateral eye and the inferio-lateral muscle group (inferior oblique, inferior rectus and lateral rectus muscles) in the contralateral eye. Thus a simple and distinct axiom was found in the pattern of the reflex-response of the extraocular muscles. Inhibition of the unilateral canals elicited the extraocular muscle responses contrary to those observed by excitation of the canal. Based on the present experimental results, it was demonstrated that the functional interrelations between the semicircular canals and extraocular muscles are rather equivalent in the frontal eyed cats (with binocular vision) and lateral eyed rabbits (with monocular vision). Therefore the previous thesis that the vestibuloocular relations vary from species to species awaits experimental reevaluation.

• Geomechanics and Engineering
• /
• 제29권1호
• /
• pp.91-97
• /
• 2022

The cohesive non-swelling soil (CNS) cushion technology has been widely applied in the subgrade and slope improvement at expansive soil regions. However, the mechanism of the inhibition effect of the CNS layer on expansive soil (ES) has not been fully understood. We performed four outdoor model tests to further understand the inhibition effect, including different kinds of upper layer and thickness, under the unidirectional seepage condition. The swelling deformation, soil pressure, and electrical resistivity were constantly monitored during the saturation process. It is found that when a CNS layer covered the ES layer, the swelling deformation and electrical resistivity of the ES layer decreased significantly, especially the upper part. The inhibition effect of the CNS layer increases with the increase of CNS thickness. The distribution of vertical and lateral soil pressure also changed with the covering of a CNS layer. The electrical resistivity can be an effective index to describe the swelling deformation of ES layer and analyze the inhibition effect of the CNS layer. Overall, the CNS deadweight and the ion migration are the major factors that inhibit the swelling deformation of expansive soil.

• 한국발생생물학회:학술대회논문집
• /
• 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
• /
• pp.24-25
• /
• 2003

The zebrafish (Danio rerio) is now the pre-eminent vertebrate model system for clarification of the roles of specific genes and signaling pathways in development. I will talk about positional cloning of two developmental mutants in zebrafish. The first mutant is headless: The vertebrate organizer can induce a complete body axis when transplanted to the ventral side of a host embryo by virtue of its distinct head and trunk inducing properties. Wingless/Wntantagonists secreted by the organizer have been identified as head inducers. Their ectopic expression can promote head formation, whereas ectopic activation of Wnt signalling during early gastrulation blocks head formation. These observations suggest that the ability of head inducers to inhibit Wntsignalling during formation of anterior structures is what distinguishes them from trunk inducers that permit the operation of posteriorizing Wnt signals. I describe the zebrafish headless (hdl) mutant and show that its severe head defects are due to a mutation in T-cell factor-3 (Tcf3), a member of the Tcf/Lef family. Loss of Tcf3 function in the hdl mutant reveals that hdl represses Wnt target genes. I provide genetic evidence that a component of the Wntsignalling pathway is essential in vertebrate head formation and patterning. Second mutant is mind bomb: Lateral inhibition, mediated by Notch signaling, leads to the selection of cells that are permitted to become neurons within domains defined by proneuralgene expression. Reduced lateral inhibition in zebrafish mib mutant embryos permits too many neural progenitors to differentiate as neurons. Positional cloning of mib revealed that it is a gene in the Notch pathway that encodes a RING ubiquitin ligase. Mib interacts with the intracellular domain of Delta to promote its ubiquitylation and internalization. Cell transplantation studies suggest that mib function is essential in the signaling cell for efficient activation of Notch in neighboring cells. (중략)

• 한국발생생물학회지:발생과생식
• /
• 제7권2호
• /
• pp.69-80
• /
• 2003

대량의 발생 유전학적 연구가 가능한 척추동물로서 최근 제브라피쉬가 새로운 동물모델로 급부상하고 있다 다양한 형태의 돌연변이들로부터 새로운 유전자들이 발굴되어지고 있으며, 인간 유전체의 기능 분석 수단으로 활용되어지고 있다. 신경계의 형성과 분화에 이상이 있는 hendless와 mind bomb이라는 두 가지 돌연변이주에서 positional cloning에 의한 원인 유전자의 발굴과 기능 분석의 예로써 현재 제브라피쉬의 연구 현황을 살펴보고자 한다. headless의 원인 유전자로 Tcf-3가 밝혀졌으며, 초기 발생단계에서 Wnt 신호전달이 두뇌의 형태형성과 영역 결정에서 핵심적 역할을 하고 있다는 사실이 밝혀졌다. mind bomb에서의 비정상적인 신경세포의 운명 결정은 lateral inhibition과 Notch 신호전달의 결함에 의한 것이고, 그 원인 유전자는 Notch ligand인 Delta에 결합하는 새로운 ubiquitin E3 ligase로 밝혀졌다. 이러한 돌연변이를 통한 연구는 현재 인간 질환모델의 개발이라는 방향으로 확대되고 있다.

• Journal of Ginseng Research
• /
• 제20권3호
• /
• pp.248-255
• /
• 1996

This study was devised to observe in vitro, the inhibitory effects of acidic polysaccharide fractions from Korean red ginseng (KRG) and white ginseng (KWG) on the lipolytic action of loxohormone-L and on angiotensin converting enzyme (ACE, peptidyldipeptidase hydrolase, EC 3.4.15.1) . The crude acidic polysaccharides (CAP) extracted from main and lateral roots of KRG and KWG were separately purified through several procedures. The total inhibitory activities on the lipolytic action of toxohormone-L of CAP from main roots of KRG and KWG was higher than those of CAP from lateral roots of KRG and KWG, respectively, and that of CAP from main root of KRG was 3.1 times higher than that of CAP from main root of KWG. The specific activity of CAP from main root of KRG was measured as 5.40 units/mg, when one unit was defined as the amount giving 50% inhibition on toxohormone-L induced lipolysls. A subfraction named PG4 3 obtained by replanted chromatography on DEAE-TOYOPEARL 650M gave the specific activity of 24.4 units/mg. On the other hand, it was found that the total inhibitory activity on ACE of CAP from lateral root of KRG was the highest among the 4 kinds of CAP, but the specific activity of CAP from lateral root of KWG was the highest.

• The Korean Journal of Physiology and Pharmacology
• /
• 제7권6호
• /
• pp.303-306
• /
• 2003

Metabotropic glutamate receptors (mGluRs), classified into three groups (group I, II, III), play a critical role in modulation of synaptic transmission at central and peripheral synapses. In the present study, extracellular field potential recording techniques were used to investigate effects of mGluR agonists on excitatory synaptic transmission at thalamic input synapses onto the lateral amygdala. The non-selective mGluR agonist t-ACPD ($100{\mu}M$) produced reversible, short-term depression, but the group III mGluR agonist L-AP4 ($50{\mu}M$) did not have any significant effects on amygdala synaptic transmission, suggesting that group I and/or II mGluRs are involved in the modulation by t-ACPD. The group I mGluR agonist DHPG ($100{\mu}M$) produced reversible inhibition as did t-ACPD. Unexpectedly, the group II mGluR agonist LCCG-1 ($10{\mu}M$) induced long-term as well as short-term depression. Thus, our data suggest that activation of group I or II mGluRs produces short-term, reversible depression of excitatory synaptic transmission at thalamic input synapses onto the lateral amygdala. Considering the long-term effect upon activation of group II mGluRs, lack of long-term effects upon activation of group I and II mGluRs may indicate a possible cross-talk among different groups of mGluRs.

• 대한물리치료과학회지
• /
• 제29권3호
• /
• pp.21-28
• /
• 2022

Background: Hamstring shortness results in the inappropriate activation of the quadriceps femoris because of the loss of the reciprocal inhibition mechanism. The purpose of this study was to investigate the effects of that activation during lunge exercises on the vastus medialis, vastus lateralis, medial, and lateral hamstrings in participants with hamstring shortness and normal length. Design: Quasi-experimental design Methods: Participants were divided into a hamstring shortness group(n=20) and a hamstring normal length group(n=23), based on a hamstring length test. During lunge exercises, muscle activation of the vastus lateralis, vastus medialis, medial, and lateral hamstrings were measured by electromyography. Results: Each muscle tested was less activated in the hamstring shortness group than in the hamstring normal length group. However, there was no statistically significant difference between the groups (p>.05). Conclusion: Although there was no significant difference between the shortness and normal hamstring groups during short lunge exercise time, longer exercising periods will result in the inappropriate activation of the quadriceps femoris. During lunge exercise, hamstring shortness causes an imbalance activation of quadriceps femoris and hamstring, and continuous hamstring shortness can cause damage on joints of lower limb.

• 센서학회지
• /
• 제12권2호
• /
• pp.57-65
• /
• 2003

CMOS 공정을 이용한 윤곽검출 시각칩 설계시, 넓은 범위의 광강도에 대해서 이미지의 특징검출을 위하여 국소 광적응기능이 필요하다. 국소 광적응이란 망막내 수평억제(lateral inhibition) 기능을 행하는 수평세포를 이용하여 입력 광강도에 응답하는 국소적인 수평세포층의 수용야 크기를 변화시켜 동일한 출력레벨을 얻는 것이다. 따라서, 배경광보다 조금 크거나 아주 큰 입력광의 변화가 있을 때 동일한 출력레벨을 얻을 수 있다. 본 연구에서는, 망막내 수평세포를 p-MOSFET로 구성된 저항성 회로망으로 모델링 및 해석하고, 이를 이용하여 설계된 시각칩의 국소 광적응 메커니즘을 검증하였다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1989년도 하계종합학술대회 논문집
• /
• pp.655-658
• /
• 1989

The characteristics of proton-diffused $LiNbO_3$ optical waveguides with self-aligned $SiO_2$-cladding are reported. When the proton diffusion occurs, the $SiO_2$-cladding limits the lateral diffusion of protons by out-diffusion of protons in unclad region. Proton indiffusion in depth direction is promoted by inhibition of out-diffusion in clad region. Consequently, the mode profile in depth direction can be nealy symmetric. The extent of the proton exchange was observed by measuring the infrared absorption peak at about $3500cm^{-1}$. It is confirmed that proton diffusion with $SiO_2$-cladding has structural excellency.