보리·밀의 有效分蘖莖率과 主要形質과의 相關

金興培 동국대학교 농림과학연구소 1995 農林科學 論文集 Vol.19 No.-

The percentage of spike-bearing tillers in barley(Hordeum vulgare L.) and wheat(Triticum aestivum L.) was considered to be proper method in comparison of tillers instead of counting number of tillers in these crops. Varietal differences of spike-bearing tillers were significant in barley and wheat. In barley the highest percent of spike-bearing tillers was 98.4% and that of lowest was 88.6%. The percentage of spike-bearing tillers in wheat was higher than barley. The highest was 99.6% and the lowest was 90.8%. Other 6 characters also showed varietal difference both barley and wheat. Relationships between percentage of spike-bearing tillers and 6 characters of barley were all negative but only spike length showed significant correlation. Correlation coefficient between percentage of spike-bearing tillers and spike length was positive and significant in wheat. Except the spike length in wheat, other 5 characters were negatively correlated with percentage of spike-baring tillers. Of these culm length, number of grain, and spike weight showed highly significant correlation.

퍼팅그린의 마모와 골프공의 구름에 미치는 골프화의 영향

심포룡,심규열 한국잔디학회 1997 한국잔디학회지 Vol.11 No.3

The metal spikes evaluated in this study significantly affected more negative on the turf wear and ball speed of putting green than alternative plastic spikes. 1.The metal spikes caused the most amount of wear compared with plastic spikes, athletic shoes and mountain-climbing shoes. On the other hand, athletic shoes caused the least amount of wear. Plastic spikes caused wear more than athletic shoes, hut apparently wear less than metal spikes. The wear from metal spike repaired later than any other tread types. 2.The wear from all kinds of shoe treads in wetcondition green were higher than in dry-condition green and the wear from metal spikes was more severe compared with plastic spikes in both green condition. 3. Ball speed of heavy compaction area by metal spike was reduced about 9% compared with that of light compaction area, hecause metal spikes made many holes in the putting green surface. On the other hand, plastic spikes did not affect hall speed of heavy and light compaction area in the putting green. Key words: Metal spike, Plastic spike, Wear, Ball speed.

앞관자엽극파의 쌍극자전류원: 방향의 임상적 의미

김영수,권오영,정석원,손승남,김수경,강희영,박기종,최낙천,임병훈 대한신경과학회 2011 대한신경과학회지 Vol.29 No.3

Background: The voltage topography of temporal spikes has two distinct patterns, designated type I and type II; the orientation of the current-dipole source (O-CDS) of type I spikes tends to be oblique, while that of type II spikes tends to be horizontal. The purpose of this study was to identify the effects of the O-CDS of anterior temporal spikes on clinical factors including onset age, seizure frequency, secondary generalization, disease duration, intractability, polytherapy, febrile seizure, hippocampal sclerosis, and neocortical-temporal aura. Methods: We examined the scalp electroencephalograms of 24 patients with temporal lobe epilepsy (TLE) and anterior temporal spikes. A spatiotemporal dipole model was applied to determine the O-CDS of the averaged spikes in each patient. We performed current-source analysis of multiple spatiotemporal dipole models using Brain Electrical Source Analysis software. The patients were divided into two subgroups according to their O-CDS pattern: oblique and horizontal. Clinical factors were compared between the two groups. Results: Sixteen patients were classified into the oblique group, and 8 patients into the horizontal group. A neocortical-temporal aura was more commonly observed in the horizontal group (p<0.05), while drug-resistance tendencies were more commonly observed in the oblique group (p<0.1). Conclusions: The horizontal O-CDS of anterior temporal spikes may be more frequently associated with a neocortical-temporal aura than the oblique O-CDS in TLE. In addition, the oblique O-CDS pattern suggests a tendency toward drug resistance. The findings of this study imply that the oblique O-CDS pattern of anterior temporal spikes may provide additional electrophysiologic information regarding drug-resistant mesial TLE. Background: The voltage topography of temporal spikes has two distinct patterns, designated type I and type II; the orientation of the current-dipole source (O-CDS) of type I spikes tends to be oblique, while that of type II spikes tends to be horizontal. The purpose of this study was to identify the effects of the O-CDS of anterior temporal spikes on clinical factors including onset age, seizure frequency, secondary generalization, disease duration, intractability, polytherapy, febrile seizure, hippocampal sclerosis, and neocortical-temporal aura. Methods: We examined the scalp electroencephalograms of 24 patients with temporal lobe epilepsy (TLE) and anterior temporal spikes. A spatiotemporal dipole model was applied to determine the O-CDS of the averaged spikes in each patient. We performed current-source analysis of multiple spatiotemporal dipole models using Brain Electrical Source Analysis software. The patients were divided into two subgroups according to their O-CDS pattern: oblique and horizontal. Clinical factors were compared between the two groups. Results: Sixteen patients were classified into the oblique group, and 8 patients into the horizontal group. A neocortical-temporal aura was more commonly observed in the horizontal group (p<0.05), while drug-resistance tendencies were more commonly observed in the oblique group (p<0.1). Conclusions: The horizontal O-CDS of anterior temporal spikes may be more frequently associated with a neocortical-temporal aura than the oblique O-CDS in TLE. In addition, the oblique O-CDS pattern suggests a tendency toward drug resistance. The findings of this study imply that the oblique O-CDS pattern of anterior temporal spikes may provide additional electrophysiologic information regarding drug-resistant mesial TLE.

맥류의 유수발육기 저온장해유형과 피해시기 분류

구본철,박문웅,김기준,안종국,이춘우,윤의병 韓國作物學會 2003 Korean journal of crop science Vol.48 No.3

보리, 밀 품종의 조숙화와 온난한 겨울로 인하여 봄에 나타나는 저온장해가 최근에 자주 발생하는데 생육재생기 이후 발생하는 저온장해의 양상, 발생시기 및 증상을 구명하고자 자연조건과 저온항온기 그리고 포장의 비닐 피복을 이용한 저온처리시험을 실시한 결과를 보면 다음과 같다. 1. 저온장해중 줄기 고사는 -2.4∼-10.2℃ , 퇴화, 백수, 탈색등은 -2.4∼-8.6℃ ,불임은 -1.3∼-7.6℃ 의 저온에서 6-39시간 지속될 때 발생하였는데 특히 자연포장에서 많이 나타나는 저온장해는 불임과 퇴화로, 이의 유발온도는 -2.5∼-3.0℃ 였다. 2. 보리, 밀 모두 수잉기에 불임이 많이 발생하였고 출수기, 영화분화기, 화기발육기 순으로 발생정도에 차이를 보였다 백수는 출수 전후 10일에 주로 발생하였으며 발생정도는 출수후 10일>출수기>수잉기 순이었다. 3. 유수퇴화는 출수기에 가장 많이 발생한 것으로 나타났고 수잉기, 화기발육기에도 많이 발생하였다. 부분희화도 수잉기에 많이 발생하였다. 포장에서는 영화분화기의 개체들에서도 많이 발생하였다. 4. 망 탈색은 주로 밀에서 발생하였는데 수잉기에 일부 발생하긴 했으나 출수기의 식물체에서 대부분이 발생하여 출수기에 주로 나타나는 장해라 할 수 있었다. 식물체 고사는 전 생육기에 걸쳐 발생하였고 가장 심한 피해는 출수기>수잉 >영화분화기>화기 발육기 순으로 발생한 것으로 나타났다. 5. 저온장해 발생지표로 유수장, 제1절간장, 지엽-이삭간 거리가 유용하였다. 유수장이 밀에서는 망 탈색시 9.0-9.8cm, 이삭 탈색시 7.5cm, 백수발생시 5.7-9.4cm, 이삭 퇴화시 0.2-9.2cm, 줄기고사시 0.3-3.8cm로 나타났고 보리에서는 백수발생시 평균 3.4-7.0cm, 부분퇴화가 4.2-5.2cm, 퇴화가 0.4-5.4cm, 줄기 고사가 0.4-0.6cm로 차이를 보였다. 제1절간장은 보리, 밀 각각 0.3-8.4cm, 0.2-24.2cm로 신장정도에서 저온에 따른 변이를 보였고, 지엽-이삭간 거리도 보리 -2.5∼-7.4cm, 밀 -0.6-11.5cm로 신장정도에 차이가 컸다. Although the young spike of barley (Hordeum vulgare L.) or wheat (Triticum aestivum L.) is known as the most susceptible part to spring cold injury, the risk of cold injury is apt to be ignored in most breeding program due to the importance of early maturity. Based on these aspects, the types and inducing time, temperature conditions for induction and effects of cold injury on growth and yield in this study were investigated under greenhouse and field conditions through three years (1997-1999). In natural condition, low temperature around -2.4∼-10.2~circC caused the death of plant. Several cold injury types such as partial degeneration of spike, partial discoloration of leaf, spike and awn, discoloration of culm and white spike were observed at low temperature around -3.1~circC . Low temperature around -2.4∼-8.6~circC and 1.3-7.6~circC caused degeneration and sterility of spike, respectively. Most materials were prepared to the spikelet foundation stage, spikelet differentiation stage, development stage of flower organ, booting stage and heading stage, which were known having risk for cold injury in field condition. Although most of the controlled stages were sensitive to the induced low temperature, booting stage was the most sensitive stage for cold injury. All of growth stages which were treated-heading stage, booting stage, development stage of flower organ, spikelet differentiation stage, spikelet foundation stage-were responded to low temperature treatment but the symptoms revealed were very specific according to the growth stages. Ears of plant in heading stage were discolored to white. Ears of plant in booting stage were degenerated in all or part of one. Plants in spikelet differentiation stage were sterile in all or part of one. When tried to detect the specific differences between normal and cold injured plants in appearance, spike length, distance between spike and flag leaf and the first internode length could be the critical points for occurrence of spike death caused by cold injury. In barley, the elongation of spike was stopped on 3.2cm after occurrence of spike degeneration, 4.7cm after occurrence of partial degeneration of spike, 5.0cm after occurrence of white spike. In wheat, it was stopped on 1.6cm after occurrence of stem death, 3.3cm after occurrence of spike degeneration, 8.3cm after occurrence of partial degeneration of spike, 8.1cm after occurrence of white spike, 7.5cm after partial discoloration of leaf and 9.3cm after partial discoloration of spike. The obtained results from low temperature treatment induced in growth chamber were similar to the field experiment, Beacuse the death of spikes was more when low temperature was treated two times than one times, the temperature should be upgrade to -3~circC in order to get the same condition with field test.

Effect of Sparse Random Connectivity on the Stochastic Spiking Coherence of Inhibitory Subthreshold Neurons

홍덕근,임우창,김상윤 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.4

We study the e®ect of network structure on the stochastic spiking coherence (i.e., collective coherence emerging via cooperation of noise-induced neural spikings) in an inhibitory population of subthreshold neurons (which cannot ¯re spontaneously without noise). Previously, stochastic spiking coherence was found to occur for the case of global coupling. However, \sparseness" of a real neural network is well known. Hence, we investigate the e®ect of sparse random connectivity on the stochastic spiking coherence by varying the average number of synaptic inputs per neuron Msyn. From our numerical results, stochastic spiking coherence seems to emerge if Msyn is larger than a threshold M^*_(syn) whose dependence on the network size N seems to be quite weak. This stochastic spiking coherence may be well visualized in a raster plot of neural spikes. For a coherent case, partially-occupied \stripes" (composed of spikes and indicating collective coherence) appear. As Msyn is decreased from N ¡ 1 (globally-coupled case), the average occupation degree of spikes increases very slowly. On the other hand, the average pacing degree between spikes (representing the precision of spike timing) decreases slowly, but near M^*_(syn) its decrease becomes very rapid. This decrease in the pacing degree can also be well seen through merging of multiple peaks in the interspike interval histograms. Due to the e®ect of the pacing degree, the degree of stochastic spiking coherence decreases abruptly near the threshold M^*_(syn).

BAPTA-AM이 뇌허혈손상에 미치는 신경방어적효과

오재인,유계희,박윤관,정흥섭,이기찬,이훈갑 대한신경외과학회 1997 Journal of Korean neurosurgical society Vol.26 No.3

Stochastic spike synchronization in a small-world neural network with spike-timing-dependent plasticity

Kim, Sang-Yoon,Lim, Woochang Elsevier 2018 Neural networks Vol.97 No.-

<P><B>Abstract</B></P> <P>We consider the Watts–Strogatz small-world network (SWN) consisting of subthreshold neurons which exhibit noise-induced spikings. This neuronal network has adaptive dynamic synaptic strengths governed by the spike-timing-dependent plasticity (STDP). In previous works without STDP, stochastic spike synchronization (SSS) between noise-induced spikings of subthreshold neurons was found to occur in a range of intermediate noise intensities. Here, we investigate the effect of additive STDP on the SSS by varying the noise intensity. Occurrence of a “Matthew” effect in synaptic plasticity is found due to a positive feedback process. As a result, good synchronization gets better via long-term potentiation of synaptic strengths, while bad synchronization gets worse via long-term depression. Emergences of long-term potentiation and long-term depression of synaptic strengths are intensively investigated via microscopic studies based on the pair-correlations between the pre- and the post-synaptic IISRs (instantaneous individual spike rates) as well as the distributions of time delays between the pre- and the post-synaptic spike times. Furthermore, the effects of multiplicative STDP (which depends on states) on the SSS are studied and discussed in comparison with the case of additive STDP (independent of states). These effects of STDP on the SSS in the SWN are also compared with those in the regular lattice and the random graph.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An excitatory small-world network of subthreshold neurons is considered. </LI> <LI> Effect of spike-timing-dependent plasticity on spike synchronization is investigated. </LI> <LI> Both the additive and the multiplicative case are considered. </LI> <LI> A “Matthew” effect in synaptic plasticity is found to occur. </LI> <LI> Emergence of potentiation and depression is investigated via microscopic studies. </LI> </UL> </P>

시계열 데이터를 위한 스파이크 인코딩 최신 연구 동향

권나애,최윤선,유연경,이병한 대한전자공학회 2024 전자공학회논문지 Vol.61 No.6

스파이킹 신경망(Spiking Neural Network, SNN)은 실제 생물학적 뇌의 동작을 모사하여 스파이크로 알려진 이산 데이터를 통해 정보를 처리한다. 스파이크는 막전위가 임계치를 초과할 때 생성되며, 이렇게 생성된 스파이크는 SNN 내의 노드 간 정보 통신에 사용된다. 스파이크를 통한 정보 전송 방법은 스파이크 데이터의 희소성 특징 덕분에 에너지 절약에 있어서 효율적이다. SNN 모델은 스파이크의 발화 타이밍을 활용하여 시간 데이터를 처리하는 데에 적합하며, 심층 신경망(Deep Neural Network, DNN)에 비해 비교적 낮은 계산 비용으로 유사한 성능을 달성할 수 있는 이점을 제공한다. 본 연구에서는 시간 관련 정보를 효율적으로 처리하는 스파이크 인코딩 방법을 조사하고, 최근 스파이크 인코딩 기술을 아날로그 시계열 데이터에 적용하는 데 중점을 둔다. 본 논문에서는 HSA, BSA, Burst 및 TTFS 네 가지 인코딩 방법을 역합성곱 기반 인코딩 및 발화 시간 코딩 방법으로 분류한다. 더불어, 간단한 분류 모델을 사용하여 각 인코딩 방법에 따른 정확도를 측정하고 분석을 수행하고, 시계열 데이터 분류 작업에 가장 적합한 인코딩 방법을 제시한다. A Spiking Neural Network (SNN) processes information through discrete electrical events, emulating the behavior of neurons observed in the brain, known as spikes. Spikes are generated when the membrane potential exceeds a specific threshold, and these generated spikes are used to communicate information between nodes within SNNs. This event-driven method of information transmission is energy-efficient because of the sparsity of spike data. SNN models can provide the advantage of accomplishing tasks with reduced computational resources, while enabling comparable performance to Deep Neural Networks (DNNs) in processing temporal data by leveraging spike timing. This research investigates methods for efficiently handling time-related information, with a focus on applying recent trends in spike encoding techniques to analog time-series data. We categorize four encoding methods - HSA, BSA, Burst, and TTFS - into deconvolution-based encoding and temporal coding methods. We measure their accuracy by utilizing a simple classification model and conduct analysis to identify the most suitable encoding method for time-series data classification task.

Spike Frequency Adaptation in Neurons of the Central Nervous System

Ha, Go Eun,Cheong, Eunji The Korean Society for Brain and Neural Science 2017 Experimental Neurobiology Vol.26 No.4

<P>Neuronal firing patterns and frequencies determine the nature of encoded information of the neurons. Here we discuss the molecular identity and cellular mechanisms of spike-frequency adaptation in central nervous system (CNS) neurons. Calcium-activated potassium (K<SUB>Ca</SUB>) channels such as BK<SUB>Ca</SUB> and SK<SUB>Ca</SUB> channels have long been known to be important mediators of spike adaptation via generation of a large afterhyperpolarization when neurons are hyper-activated. However, it has been shown that a strong hyperpolarization via these K<SUB>Ca</SUB> channels would cease action potential generation rather than reducing the frequency of spike generation. In some types of neurons, the strong hyperpolarization is followed by oscillatory activity in these neurons. Recently, spike-frequency adaptation in thalamocortical (TC) and CA1 hippocampal neurons is shown to be mediated by the Ca<SUP>2+</SUP>-activated Cl- channel (CACC), anoctamin-2 (ANO2). Knockdown of ANO2 in these neurons results in significantly reduced spike-frequency adaptation accompanied by increased number of spikes without shifting the firing mode, which suggests that ANO2 mediates a genuine form of spike adaptation, finely tuning the frequency of spikes in these neurons. Based on the finding of a broad expression of this new class of CACC in the brain, it can be proposed that the ANO2-mediated spike-frequency adaptation may be a general mechanism to control information transmission in the CNS neurons.</P>

솟는 고드름의 형성과정에 관한 관찰, 실험 및 분석

윤마병,김희수,손정호,양종우 한국지구과학회 2009 한국지구과학회지 Vol.30 No.4

In this study, from January 2006 to February 2009, we observed 107 ice spikes formed in a natural state, and analyzed their environment. We developed an experimental device to reproduce ice spikes in laboratory and successfully made 531 ice spikes. We analyzed the process of the formation and the principle of how those ice spikes grow through videotaped data of the formation in the experiment. In the natural world, when the surface of water and the lower part of a vessel begin to freeze, a vent(breathing hole) develops at the surface where an ice is not frozen; this vent serves as the seed of an ice spike. It is assumed that the volume expansion of ice in the vessel which occurs when water freezes makes the supercooled water go upward through the vent and becomes an ice bar called an ice spike. In the laboratory, however, when distilled water is poured into an ice tray cube and kept in the experimental device for about one and a half hours at a temperature of -12--13℃, a thin layer of ice then begins to develop on the surface of the water, the vent is formed, and ice spikes form for about 10-30 minutes. These spikes stop growing when the end becomes clogged. Ice spikes can be described as falling into seven categories of shape, with the apex type topping the list followed by the slant type in the natural state and the vertical type predominating in the laboratory. 본 연구에서는 2006년 1월부터 2009년 2월까지 자연 상태에서 만들어진 솟는 고드름(n=107)을 관측, 분석하여 실험실에서 솟는 고드름을 재현할 수 있는 실험 장치를 개발했다. 이 장치를 이용하여 동영상 관측과 실험(531개의 솟는 고드름 생성)을 통해 그 생성과 성장 원리를 연구했다. 용기의 아래 부분이 위쪽 보다 더 차가운 상태에서 용기 바닥과 물 표면에서부터 얼음이 얼기 시작하는데, 표면에서 얼음이 얼지 않는 부분을 숨구멍이라고 하며 이곳으로부터 솟는 고드름이 만들어지기 시작한다. 솟는 고드름이 만들어지기 시작한 후 계속 성장하기 위해서는 용기 하부의 물이 얼음으로 변할 때의 부피 팽창 효과와 숨구멍을 통해 올라오는 과냉각수의 빠른 빙결 효과 등이 관련된다. 실험 장치에서 아이스 트레이 큐브에 증류수를 넣고, -12--13℃의 온도를 약 1시간 30분 정도 유지시키면 수면에 살얼음과 숨구멍이 생기기 시작한다. 숨구멍으로부터 생기기 시작한 솟는 고드름은 10-30분 동안 성장하고, 끝이 막히면서 성장을 멈춘다. 솟는 고드름의 형태는 7가지로 분류되며 자연 상태에서는 꼭지형과 기운형이 많았고, 실험실에서는 수직형이 가장 많았다.