• 한국소음진동공학회논문집
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• 제22권1호
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• pp.15-21
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• 2012

This paper deals with an experimental study on the reaction of muscles by functional electrical stimulation(FES) with the design and fabrication of an ankle reaction apparatus. The ankle reaction apparatus consists of a circuit part and a kinematic part, and it monitors reaction time for a particular angle of joint rotation according to FES. The experimental results showed that the change of the ankle rotation angle was linearly proportional to the change of the magnitude of FES. It also showed that the muscle's reaction time was constant no matter how large the magnitude of the stimulus. The results of this paper can be applied to develop an active-type walking-assistance robot.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1578-1583
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• 2003

Time-Optimal solutions for attitude control with reaction wheels as well as with thrusters are studied. The suggested varying-time-sharing ratio thrusting is found to reduce the maneuvering time enormously. The hybrid control such as sequential hybrid and simultaneous hybrid with reaction wheels and thrusters are considered. The results show that simultaneous hybrid method reduces the maneuver time very much. Spacecraft model is KOrea Multi-Purpose SATellite(KOMPSAT)-II, which is being developed by KARI in KOREA as an agile maneuvering satellite.

• 한국식품영양학회지
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• 제17권3호
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• pp.313-321
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• 2004

Maillard reaction을 이용하여 제조한 여러 종류의 reaction meat flavor로부터 함유황 이원자고리 화합물을 분리, 농축한 다음 GC와 GC-MSD를 이용하연 함유황 이원자고리 화합물의 profile을 얻어 성분의 확인 및 정량분석을 시도하여 다음과 같은 결론을 얻었다. 1. Reaction meat flavor의 함유황 이원자고리 화합물의 profile을 조사한 결과 7종의 thiozole과 11종의 thiophene을 동정 할 수 있었으며, thiophene, thinzolidine, 4-methyl-5-thiazole ethanol이 주요 생성 화합물이었다. 2. 함유황 이원자고리 화합물의 경우 반응조건(온도, 시간)의 변화에 따라 생성성분의 종류에는 거의 차이가 없었지만 그 양에 있어서는 상당한 차이가 나타났고, 반응온도가 높을수록, 반응시간이 길수록 구조가 복잡한 함유황 이원자고리 화합물과 caramellike note를 갖는 함산소 이원자고리 화합물이 보다 많이 생성되었으며, 반대로 반응온도가 낮고 반응시간이 짧을수록 함유황이 원자고리 화합물의 생성이 비교적 적었다. 3. 수분함량 50%, 반응온도 10$0^{\circ}C$, 반응시간 2시간의 반응조건에서 thiophene과 thiazole 같은 비교적 구조가 단순한 함유황 이원자고리 화합물의 생성율이 가장 높았으며, reaction meat flavor의 발현을 위하여는 10$0^{\circ}C$ 이내의 온도에서 2시간을 넘기지 않고 반응시키는 것이 좋았다. 4. 수분함량이 낮으면 반응온도 및 시간을 낮고 짧게, 수분함량이 높을수록반응온도 및 시간은 높고 길게 반응시키는 등 수분함량은 반응온도 및 시간과 밀접한 관계에 있으므로 수분함량에 따라 반응조건을 변화시킴으로써 일정한 flavor profile을 계속하여 얻을 수 있었다. 이와 같이 원료를 단순화하여 reaction meat flavor를 제조한 다음 함유황 이원자고리 화합물을 추출, 분리, 농축하여 분석함으로써 향료산업 및 조미식품산업에서 reaction meat flavor의 생산에 필요한 하나의 방향을 제시할 수 있었다.

• 환경위생공학
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• 제10권1호
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• pp.98-105
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• 1995

In the treatment of wastewater or sewage plant sludge with high solid concentration, high rate digestion process in which heating and mixing occur at a time is mainly used, and in the case of wastewater containing solid matter below 1000mg/ℓ the recently developed AF or UASB is developed Recently and commonly utilized. But these processes have weakpoints such as clogging of packing media and need of long period of trial run after microorganism granulation. In this point of view, there are active researches on the ASBR( anaerobic sequence batch reaction ) that is capable of treating of organic matter with reactor that has no packing materials and controlling the inflow time, reaction time sedimentation time and outflow time by time control without loss of microorganisms. The objectives of this study are to evaluate the efficiency of ASBR process according to the reaction time, change of treated water quality and gas output rate in the treatment of wheat plant wastewater.

• Journal of Ginseng Research
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• 제19권3호
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• pp.249-253
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• 1995

In the browning reaction of Korean ginseng, it appears that enzymatic and non-enzymatic browning reaction occurred in the initial stage of heating fresh ginseng at low temperature, and then non-enzymatic browning reaction followed in the drying period after heating. Activation energy of the browning reaction for red ginseng was about 9.0 kcal/mol. Browning reaction of red ginseng was accede- rated with an increase in steaming time, and a great extent of browning reaction occurred between 60-90 min of steaming at 10$0^{\circ}C$. Browning pigments of red ginseng were mostly water soluble subset.

• The Journal of Korean Physical Therapy
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• 제26권3호
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• pp.191-195
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• 2014

Purpose: The purpose of this study is to investigate whether types of sensory-stimuli cues in terms of visual, auditory, and visuoauditory cues can be affected to motor sequential learning in healthy adults, using serial reaction time task. Methods: Twenty four healthy subjects participated in this study, who were randomly allocated into three groups, in terms of visual-stimuli (VS) group, auditory-stimuli (AS) group, and visuoauditory-stimuli (VAS) group. In SRT task, eight Arabic numbers were adopted as presentational stimulus, which were composed of three different types of presentational modules, in terms of visual, auditory, and visuoauditory stimuli. On an experiment, all subjects performed total 3 sessions relevant to each stimulus module with a pause of 10 minutes for training and pre-/post-tests. At the pre- and post-tests, reaction time and accuracy were calculated. Results: In reaction time, significant differences were founded in terms of between-subjects, within-subjects, and interaction effect for group ${\times}$ repeated factor. In accuracy, no significant differences were observed in between-group and interaction effect for groups ${\times}$ repeated factor. However, a significant main effect of within-subjects was observed. In addition, a significant difference was showed in comparison of differences of changes between the pre- and post-test only in the reaction time among three groups. Conclusion: This study suggest that short-term sequential motor training on one day induced behavioral modification, such as speed and accuracy of motor response. In addition, we found that motor training using visual-stimuli cue showed better effect of motor skill acquisition, compared to auditory and visuoauditory-stimuli cues.

• 대한인간공학회지
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• 제36권5호
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• pp.459-466
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• 2017

Objective: This study examined two traffic signals with a countdown indicator in terms of driver's reaction time and subjective satisfaction score and their performance was compared with a standard traffic signal in driving simulation. Background: Dilemma zone is created when a traffic light changes at intersections. It often pushes drivers to rush in urgent and premature decision making whether to go or stop and thus induces unnecessary mental load among drivers, which may lead to sudden conflicts with following vehicles at intersections. Method: Forty college students (male: 20, female: 20) participated in this driving simulation study. Three traffic signals were employed: (1) standard traffic signal; (2) countdown-separated signal; and (3) countdown-overlaid signal. The countdown-separated and countdown-overlaid signals were designed to inform drivers of the remaining time of a green light before tuning to an amber light. Reaction times (sec) and satisfaction scores (7-point scale) for the two signals with a countdown indicator were compared with those for the standard traffic signal. Results: Reaction times of the countdown-separated (0.49 sec) and countdown-overlaid (0.43 sec) signals were significantly shorter than that of the standard signal (0.67 sec). Satisfaction scores of the countdown-separated (5.3 point) and countdown-overlaid (5.6 point) signals were greater than that of the standard signal (3.8 point). Lastly, the countdown-overlaid signal showed better performance than the countdown-separated signal, but their differences in reaction time (0.06 sec) and satisfaction score (0.3 point) were small. Conclusion: Traffic signals with a countdown indicator can improve drivers' reaction time and satisfaction score than the standard traffic signal. Application: Traffic signals with a countdown indicator will be useful for reducing the length of dilemma zone at intersections, by allowing drivers to predict the remaining time of a green light.

• 대한불안의학회지
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• 제4권2호
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• pp.99-103
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• 2008

Objectives : The authors sought to examine the differences in the number of P300 detected by subjects in experimental and control groups when exposed to relevant stimuli. In addition, the authors tried to determinethe subjects' reaction time when asked to respond to relevant stimuli. Methods : The subjects were 20 informed female volunteers aged 22-38 years (median age : 24). Relevant stimuli (concealed information) were created by unknowingly exposing the two groups to obscene pictures and semantic questions. The number of P300 detected and the length of reaction time were compared between the two groups. Results : Contrary to theauthors' expectations, there were no significant differences in the number of P300 detected or in the length of reaction time between the two groups. Conclusions : These results indicate that, unlike a polygraph test, concealed information tests adopting P300 and reaction time as major physiological responses ofsubjects exposed to meaningful personal information might not serve as a valid practical tool in the field of criminal psychology. However, further studies involving a greater number of subjects are needed before a final conclusion regarding the validity of this new type of concealed information test can be drawn.

• Journal of Preventive Medicine and Public Health
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• 제30권3호
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• pp.577-584
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• 1997

이 연구는 최근 개발된 컴퓨터를 이용한 정신운동 기능 검사법인 Neurobehavioral Tests fur Occupational Screening(NTOS)의 타당도 평가를 위해 시도되었다. 일개 종합병원 신경과에 등록된 파킨슨병 환자 12명과 신경독성물질에 폭로된 적이 없는 근로자 21명을 대상으로 NTOS의 단순반응시간 검사, 2가지 선택반응시간 검사, 양 손의 수지타진검사를 실시하였다. 평균 단순반응시간은 근로자군은 245 msec, 환자군은 378 msec였으며, 2가지 선택반응시간은 근로자군은 444 msec, 환자군은 671 msec 로 나타나 T 검정에서 유의한 차이를 보였다. 주로 쓰는 손의 수지타진검사는 68.6회를 나타내었고, 파킨슨병 환자군은 51.6회, 주로 쓰지 않는 손은 각각 60.9회, 43.1회로 유의한 차이를 보였다. 환자군과 근로자군의 연령과 학력차이를 통계적으로 보정하고 두군에서 차이가 나는지를 알아보기 위해 공분산분석을 실시한 결과, 단순반응시간, 선택반응시간, 수지타진이 유의한 결과를 보였다. 이상으로 볼 때, NTOS는 정신운동기능의 장애를 발견할 수 있는 도구라고 생각된다. 그러나 선택반응 시간 검사의 실수 횟수 같이 상대적으로 민감하지 못한 지표에 대한 고려가 필요하며, 혼란변수를 연구 설계에서 조정할 수 있는 큰 규모의 연구와 정신운동기능의 잠재적 장애를 보이는 집단에 대한 연구들이 추후에 있어야 할 것이다.

• 한국운동역학회지
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• 제14권3호
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• pp.191-202
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• 2004

The batting performance in baseball is a repetitive movement. In order to make the stabilization of posture and the efficient shift of body weight, both the range of stance and stride are important. The previous studies explained that the consistent stride which included the amount of time, stance, and direction were needed. However, the batting performance is frequently changed according to the several speed of ball. Therefore, this study was to analyze the reaction time, the range of stance, the change of stride, and the change of GRF during the batting movement in three kinds of ball speed (120km/h, 130km/h, & 140km/h). Seven elite players are participated in this study. 1. The reaction time of the stride phase was short whereas the time of the swing phase was long according to the increasing ball speed. 2. The range of the stance was wide and the mediolateral direction of the stride was decreased according to the increasing ball speed. 3. In the three kinds of ball speed, the change of body weight was transferred to the center, the rear foot, and the front foot directions. The ball speed of 130km/h showed the high frequency of the suitable batting. At this ball speed, the movement of the body weight was shifted smoothly and the value of the Ground Reaction Force was large enough.