• 제목/요약/키워드: stimulus-duration

검색결과 76건 처리시간 0.026초

기계학습을 이용한 단일 관련자극 P300기반 숨김정보검사 (One-probe P300 based concealed information test with machine learning)

  • 김혁;김현택
    • 인지과학
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    • 제35권1호
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    • pp.49-95
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    • 2024
  • 국내 형사소송절차에서 진술의 진위여부 확인을 위해 사용하는 도구는 폴리그래프검사, 진술타당도분석, P300 기반 숨김정보검사 등이 있고, 이 중에서 폴리그래프검사의 사용빈도가 다른 도구들에 비하여 높다. 하지만, 검사결과를 뒷받침해 줄 수 있는 근거의 부족으로 인하여 재판과정에서 증거채택 가능성이 낮다. 폴리그래프검사를 뒷받침해 줄 수 있는 방법으로, 사전연구가 풍부한 P300기반 숨김정보검사가 주목을 받아 왔지만, 기존의 검사기법은 두 가지 제한점이 있어 실제 사건에서의 활용도는 낮은 편이다. 첫째, 검사에 필요한 관련자극만 3개 또는 6개 등, 사전에 노출되지 않은 정보가 다수 필요하기 때문에 실제 사건에서 사용 가능성이 낮다. 둘째, 기존의 P300기반 숨김정보검사 프로토콜에서는 관련자극과 무관련자극에 대한 P300요소 전위값을 명확하게 구분하기 위하여 오드볼패러다임을 사용하기 때문에 무관련자극에 대한 P300요소 전위값이 과소 추정될 가능성이 있다. 본 연구에서는 검사의 사용 가능성을 높이기 위하여 사전에 노출되지 않은 정보가 단 하나만 있어도 검사가 가능한 단일 관련자극을 사용하는 수정된 P300기반 숨김정보검사 프로토콜을 탐색하였고, 오드볼패러다임 사용으로 인한 무관련자극에 대한 P300요소 전위값이 과소 추정되는 문제를 보완하기 위하여 다양한 기계학습의 분류 알고리즘을 비교하였다. 연구결과 단일 관련자극으로 여성과 남성의 얼굴자극을 사용할 경우, 자극은 400ms 지속시간으로 60회 제시하고, 절단값을 유죄집단은 90%로 무죄집단은 30%로 하여 정점-정점 방법으로 P300요소 전위값을 분석하는 것이 적합함을 확인하였다. 단어자극의 경우, 지속시간을 300ms로 60회 제시하고, P300요소 전위값 분석방법은 얼굴자극과 동일하게 시행하는 것이 적합하다는 것을 확인하였다. 또한 관련자극과 무관련자극에 대한 정점-정점 P300요소 전위값을 6가지 기계학습 분류 알고리즘을 사용하여 분석한 결과, 로지스틱 회귀(LR), 선형 판별 분석(LDA), K-최근접 이웃(KNN) 알고리즘이 관련자극과 무관련자극의 분류에 적합하다는 것을 확인하였다.

대상의 크기 및 관찰거리가 시간 지각에 미치는 영향 (Effects of Object Size and Viewing Distance on Duration Perception)

  • 이원섭;김신우;이형철
    • 감성과학
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    • 제21권4호
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    • pp.91-102
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    • 2018
  • 인간이 외부 환경에 적절하게 대응하기 위해서는 정확한 시간 지각이 필요함에도 불구하고 다양한 비 시간적(non-temporal) 특성들이 시간 지각에 영향을 주는 것으로 나타났다. 그동안 시간 지각에 영향을 주는 다양한 요인들이 검증되었지만 참가자와 자극 간의 거리가 시간 지각에 영향을 주는지 직접 검증한 연구는 없다. 본 연구는 자극의 망막상 크기, 물리적 크기, 지각된 크기를 고려하여 관찰 거리가 시간 지각에 미치는 영향을 검증하였다. 연구 결과, 자극의 물리적 크기 및 지각된 크기가 동일한 실험에서 관찰 거리의 효과가 나타나지 않았으며, 자극의 망막상 크기가 동일한 실험에서만 관찰 거리의 효과가 나타났다. 이는 자극의 망막상 크기가 동일한 경우, 관찰 거리가 증가할수록 자극의 물리적 크기 또한 커지기 때문에 자극의 크기가 시간 지각에 영향을 준 결과일 수 있다. 이러한 실험 결과는 정보가 제한되지 않는 경우에 관찰거리가 변화하더라도 대상의 지속시간이 항상성 있게 지각될 수 있음을 시사한다.

민어과 어류의 명음에 관한 음향학적 특성 (Characterization of sounds produced by 3 sciaenid species)

  • 이경훈;양용수;김진구;안희춘;신종근
    • 수산해양기술연구
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    • 제43권3호
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    • pp.206-211
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    • 2007
  • The sciaenid species, which has swimbladder, generates sounds by vibrating in its length wards when spawning or getting stimulus from something else. This research analyzed on sound frequency characteristics relatives to their swimbladder length of three sciaenid species, yellow croaker(Larimichthys polyactis), brown croaker(Miichthys miiuy), and white flower croaker(Nibea albiflora). As results, the dominant frequency for yellow croaker ranged over 38.08 to 141.60Hz in wide frequency band, and the averaged pulse duration expressed in $280.3{\pm}156.0ms$. For brown croaker, the dominant frequency ranged in 49.80 to 59.57Hz, and the averaged pulse duration was $129.1{\pm}36.9ms$. Moreover, the dominant frequency of white flower croaker ranged in 73.24 to 86.91Hz, and the averaged pulse duration was $88.0{\pm}15.9ms$, it has shorter pulse duration than any two species. Therefore, the dominant frequency relatives to swimbladder length of sciaenidae showed that it had widely resonant characteristics and long pulse duration as in shorter swimbladder length. Additionally, for white flower croaker, we could confirm their behavior and sounds in response to production of recorded sounds using underwater speaker.

신생아의 통증완화를 위한 포도당 경구투여 효과 (The Effect of Oral Glucose on Pain Relief in Newborns)

  • 안혜영;장미영;허명행
    • 대한간호학회지
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    • 제36권6호
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    • pp.992-1001
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    • 2006
  • Purpose: This study was done to provide data for a nursing intervention to alleviate newborn pain clinically by investigating the effect of oral glucose. Methods: Subjects were newborns hospitalized in the nursery. Informed consent was obtained from parents of 60 newborns. A heel stick was carried out for a test on 3 groups; the experimental, placebo, and control group. The Neonatal infant pain scale(NIPS), respiration rate, heart rate, peripheral oxygen partial pressure($SpO_2$), and crying duration were measured to assess pain reaction. All neonatal behaviors were recorded on videotape. Results: There were significant differences in pain behavior during stimulus(F=4.195, p=.020), pain behavior immediately after blood-sampling (F=4.114, p=.021), and pain behavior 3 minutes after that (F=3.630, p=.033). However, there were no significant differences in heart rate, respiration rate, peripheral oxygen partial pressure or crying duration after the heel stick among the groups. Conclusions: Oral administration of glucose before a heel stick caused the reduction of neonatal pain behavior, which means that it has an effect of pain relief.

가상과 실제 손의 동기화를 통한 촉각환상 유발연구 (The Tactile Illusion evoked by a synchronous Visual Stimulus on Virtual and Real Hand)

  • Jeonghun Ku;Kim, Hosung;Kim, Kwanguk;Wonyoung Hahn;Lee, Jang-Han;Kim, Sun I.
    • 한국감성과학회:학술대회논문집
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    • 한국감성과학회 2003년도 춘계학술대회 논문집
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    • pp.84-89
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    • 2003
  • The virtual reality(VR) technology can provide various stimuli, including, visual and auditory stimuli, simultaneously in the virtual environment and encourage the user to interact. Virtual reality is a set of computer technologies, which when combined, provide an interactive interface to a computer generated world. In this world the subject can see, hear and navigate in a dynamically changing environment in which he participates as an active player, by modifying the environment according to his will. Moreover, the subject can get a feeling for the virtual environment in much the same way as one feels real life situations. In the real world, a plethora of information from various modalities may be in conflict, and modulate each other to form an illusion. In this study we investigated whether a tactile illusion on a real hand could be evoked by a virtual stimulus, the time required to generate this illusion and its duration. This study shows that the illusion occurred, and that was correlated with presence score in the virtual environment.

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족하수 환자에서의 보행기능 보조를 위한 표피 자극형 전기자극기 개발 (Development of surface electrode type electrical stimulator or supporting walk function in foot drop patients)

  • 임승관;정호춘;김규겸;진달복;박병림
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1997년도 추계학술대회
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    • pp.9-13
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    • 1997
  • The present study was designed to develop the functional electrical stimulation system in order to restore motor function of paralytic patients. We attempt to establish adequate stimulus parameters for the recovery of work unction in lower limb paralysis patients and to develop the electrical stimulation system, which is effective to protect foot drop in these patients. In our animal and human experiment, adequate stimulus condition for surface electrode on the lower limb were 0.2-0.3ms at the duration and 50 Hz, which contain 600Hz train pulse. This parameter has efficiently prevented the foot drop from lower limb paralysis, decreased muscle fatigue and induced powerful contraction of lower limb muscle.

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주정의존에서 성기능장애와 말초신경염의 연관성 (Association of Sexual Disorders with Peripheral Neuropathy in Alcohol Dependence)

  • 전진숙;한호성;김기찬;정호중
    • 생물정신의학
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    • 제4권1호
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    • pp.108-115
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    • 1997
  • The alcoholic neuropathies developed in approximately 34% of chronic alcoholics and the sexual dysfunction had been experienced in 8-54% of male alcoholics(Schiavi 1990). The aims of this study were to identify the prevalence of subclinical polyneuropathies and sexual disorders in alcohol dependence, and to evaluate the association between them. The nerve conduction velocity(NCV), electromyography(EMG), and pudendal somatosensory evoked potentials(SEPs) were tested for the male alcoholics(N=34) and controls(N=17 for NCV & EMG, N=25 for pudendal SEPs). The pudendal SEPs were measured by the following procedures, in which we stimulated the dorsal nerve of penis attached by the ring electrode(stimulus intensity, three times of threshold : stimulus rate, 1-4.7Hz : stimulus duration, 0.1 or 0.2msec), and recorded at the scalp(active electrode, 2cm behind Cz : reference electrode, Fz). The NCV and EMG detected signs of peripheral neuropathies in 79.4% of alcoholics. Among the alcoholics, 64.7% were abnormal on the pudendal SEPs. Among the alcoholics who revealed abnormality on EMG and NCV, 81.4% were abnormal on the pudendal SEPs, in which 51.9% were not responded. The P1 latencies of pudendal SEPs on neuropathic alcoholics were significantly delayed(p<0.05) than non-neuropathic alcoholics. There was a relative correlation between peripheral neuropathies and sexual disorders in the alcoholics. The prevalence of subclinical neuropathies and sexual disorders seemed to be much higher in alcohol dependence than expectation, and these two problems were relatively correlated, and our results suggested that the peripheral polyneuropathies were one of the prerequisites of sexual disorders.

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새로운 해열, 진통, 소염제인 HP228의 단독 또는 Morphine과의 병용투여가 제통효과에 미치는 영향 (Effects of HP228 on Analgesia Alone or in Combination with Morphine)

  • 이승구;이승훈;김태성;김현수;김광민
    • The Korean Journal of Pain
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    • 제12권1호
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    • pp.64-69
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    • 1999
  • Background: The new drug HP228 is a cytokine restraining agent with a broad spectrum of anti-inflammatory, analgesic, and antipyretic activity. Six healthy, adult, male volunteers were studied to determine the independent and interactive effects of HP228 and morphine on pain perception. Methods: Two groups of stimuli were applied to each volunteers before drug administration as control, 20 min after morphine and HP228 administration, and 20 min after combined administration of these two drugs. Two adhesive electrically-conducting pads were applied on opposite sides of the arm approximately 8 cm apart. The electrode were connected to an electrical impulse generator and 50 Hz 1 msec pulses of incrementally increasing intensity were delivered at 1 sec intervals. The analgesic endpoints were the current intensity (mA) at which the subject first detected the stimulus (THRESH), the intensity at which the stimulus was first idenfied as being painful (PAIN), and the intensity at which the subject requested that the stimulus be terminated due to discomfort (LIMIT). A second series of stimuli were applied immediately thereafter using 1-sec duration 50 Hz tetanus pulses with increasing intensities at 2~5 sec intervals. Results: There were significant differences between drug treatments (Morphine, HP228, HP228/Morphine) and control (No drugs) in any of the measurements (PAIN, LIMIT) except THRESH with the twitch and tetanus test. Conclusions: The data suggests that HP228 is an analgesic, but it does not appear to interact with morphine in an additive manner.

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저작근의 근전도 휴지기와 근육피로와의 관계 (A Relationship Between the EMG Silent Period and Muscle Fatigue of the Masticatory Muscle)

  • 김태훈;양덕진;강병길;조일준;이진;김성환
    • 대한전기학회논문지:시스템및제어부문D
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    • 제50권5호
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    • pp.247-254
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    • 2001
  • Silent period(SP) is transient stops of muscle activity that are induced by mechanical or electrical stimulus and the duration of silent period is a important parameter that have been associated with symptoms of masticatory dysfunction. Muscle fatigue is induced by sustained muscular contractions. It is associated with the external manifestations as the inability to maintain a desired force output, muscular tremor, and localized pain. Muscle fatigue is a parameter that have been measured or monitored the deterioration of a performance of muscles. On the study of relationship between SP and masticatory muscle fatigue, Nagasawa suggested that SP increases up to 3 min. from the beginning of clenching when the subjects performed sustained contractions at 50% maximum clenching level. In this paper, in order to evaluate a relationship between SP and muscle fatigue, 10 SPs per 1 minute are measured at 10%, 20%, 50% maximum clenching level. We used the median frequency in order to quantify the degree of muscle fatigue. However, the results shows that the duration of silent period was not significantly affected by differing levels of muscle fatigue. Therefore, we suggest that the SP is not increased or decreased as the results of muscle fatigue, also the origin of the SP generation mechanism is discussed.

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T-반사 응답의 분석을 위한 디지탈 신호 처리 시스템의 설계 (Design of a Digital Signal Processing System for Analysis of Tendon Reflex Response)

  • 김재국;권도철
    • 대한의용생체공학회:의공학회지
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    • 제17권2호
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    • pp.221-226
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    • 1996
  • Tendon reflex responses generated from mechanical stimulus had been studied for quantitative analysis of activity of tendon reflex, especially patellar tendon reflex responses are known to be a criterion for diagnosing the L3 or L4 radiculopathy. In this paper, we developed a digital signal processing system for analysis of the tendon reflex response. The system parameter, i.e., $\textit{sampling frequency, pre-amplification gain, input channel and filter bank}$ are selected by Using software switches. From the view points of flexibility, the system hardware is connected to an IBM PC for analyzing the tendon reflex parameters, amplitude, latency duration We applied the proposed system to the analysis of the patellar tendon reflex reponses. In the experiment, we measured latency, duration, amplitude of the reflex action potentials generated from vastus medialis, vastus lateralis and rectus femoris that compose quadriceps, and the measured data are analyzed througll the ANOVA test which has 5% significant level. As a result, we showed that the mean amplitude of reflex action potential at the vastus lateralis is larger than any other muscle and the mean latency of the reflex action potential at the rectus femoris is shorter than any other muscle.

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