목적 : 본 연구의 목적은 가상현실 기반 주방 과제 수행 시 나타나는 수행오류의 종류와 인지기능과의 상 관관계를 알아보고자 함이다. 연구방법 : 신경학적 결함이 없는 만 60세 이상 건강한 노인 38명을 대상으로 가상현실 환경 내에서 주방 과제를 수행하였다. 주방 과제는 잼 버터 샌드위치 만들기를 시행하였다. 주방 과제를 수행하는 동안 나타나는 수행오류 의 종류를 2명의 작업치료사가 각각 평가하였다. 아울러 캠브리지 전산화 신경 심리평가(Cambridge Neuropsychological Test Automated Battery; CANTAB)의 Stocking of Cambridge(SOC), Executive Function와 Spatial Working Memory(SWM)평가를 실시하였다. 주방 과제 시 보이는 수행오류의 빈도수와 각 인지 영역의 점수 간의 상관관계를 분석하였다. 평가자 간 신뢰도는 SPSS 12.0을 통해 분석하고, 상관관계 분석은 Python을 사용하였다. 결과 : Omission 오류는 SOC의 움직임 횟수와 SWM의 전략 사용과 통계적으로 유의미한 양의 상관을 보였다(p < .05). 반면 commission 오류는 SOC의 움직임 횟수와 통계적으로 유의미한 양의 상관관계 를 보였다(p < .001). 주방 과제를 수행하는 데 걸린 시간과 총 수행오류는 SOC의 움직임 횟수와 통계 적으로 유의미한 양의 상관관계를 보였다(p < .05). 결론 : 가상현실 기반 주방 과제에서 나타나는 수행오류는 작업기억 및 집행기능과 상관관계가 있고, 생태 학적 타당성이 높은 집행기능 평가로써 임상적으로 활용 가능성이 크다. 향후 연구에서 환자 그룹을 대 상으로 인지기능에 따른 수행오류의 특성을 더욱 면밀하게 연구해나갈 필요가 있다.

Failure to comply with the performance test requirements for the centrifugal pumps at power plants often results in performance dissatisfaction as a result of field tests. This study proposed a method of reducing the uncertainty of the field test results by evaluating the systematic error in the measurement system caused by failure to follow the test requirements using the computational fluid dynamics(CFD) technique. As a result of the evaluation of the systematic error and reflecting it in the performance test data, it was confirmed that the error occurred at a constant rate with respect to the flowrate and that the pump, which showed a difference in performance actually had the same performance.

  Enhanced machine reliability has dramatically reduced the rate and number of railway accidents but for further reduction human error should be considered together that accounts for about 20% of the accidents. Therefore, the objective of this study was t

This study is aimed at investigating the influence of different quantitative knowledge of results on the measurement error during lumbar proprioceptive sensation training. Twenty-eight healthy adult men participated and subjects were randomly assigned into four different feedback groups(100% relative frequency with an angle feedback, 50% relative frequency with an angle feedback, 100% relative frequency with a length feedback, 50% relative frequency with a length feedback). An electrogoniometer was used to determine performance error in an angle, and the Schober test with measurement tape was used to determine performance error in a length. Each subject was asked to maintain an upright position with both eyes closed and both upper limbs stabilized on their pelvis. Lumbar vertebrae flexion was maintained at for three seconds. Different verbal knowledge of results was provided in four groups. After lumbar flexion was performed, knowledge of results was offered immediately. The resting period between the sessions per block was five seconds. Training consisted of 6 blocks, 10 sessions per one block, with a resting period of one minute. A resting period of five minutes was provided between 3 blocks and 4 blocks. A retention test was performed between 10 minutes and 24 hours later following the training block without providing knowledge of results. To determine the training effects, a two-way analysis of variance and a one-way analysis of variance were used with SPSS Ver. 10.0. A level of significance was set at .05. A significant block effect was shown for the acquisition phase (p<.05), and a significant feedback effect was shown in the immediate retention phase (p>.05). There was a significant feedback effect in the delayed retention phase (p<.05), and a significant block effect in the first acquisition phase and the last retention phase (p<.05). In conclusion, it is determined that a 50% relative frequency with a length feedback is the most efficient feedback among different feedback types.

Concrete has recently been modified to have various performance and properties. However, the conventional method for predicting the compressive strength of concrete has been suggested by considering only a few influential factors. so, In this study, nine influential factors (W/B ratio, Water, Cement, Aggregate(Coarse, Fine), Fly ash, Blast furnace slag, Curing temperature, and humidity) of papers opened for 10 years were collected at 4 conferences in order to know the various correlations among data and the tendency of data. The selected mixture and compressive strength data were used for learning the Deep Learning Algorithm to derive a prediction model. The purpose of this study is to suggest a method of constructing a prediction model that predicts the compression strength with high accuracy based on Deep Learning Algorithms.

본 논문은 IMT-2000 기지국용 15 Watt Feedforward 선형전력증폭기(Linear Power Amplifier; LPA)의 구현을 위한 에러증폭기를 설계 및 제작하여, 그 성능을 평가하였다. 에러증폭기는 상호 변조 왜곡 신호(Intermodulation Distortion: IMD)만을 검출하기 위한 빼기회로, RF 신호의 세기 및 위상을 제어하기 위한 가변 감쇠기, 가변 위상변환기, 그리고 신호의 증폭을 위한 저전력증폭기, 대전력증폭기로 구성되었다. 이들 구성요소는 RO4350 기판 위에 구현되어, 틴 도금한 알루미늄 기구물 안에 바이어스 회로와 함께 집적하였다. 제작시 RF 회로부의 바이어스 회로에 전원을 공급하기 위하여 내벽에 관통형 커패시터를 삽입하여 DC 전원에 의한 스퓨리어스 성분이 제거되도록 하였다. 제작된 에러증폭기는 45 dB 이상의 이득, ± 0.66 dB의 이득평탄도, -15 dB 이하의 입력반사 손실 특성을 나타내었다. 또한 성능을 평가하기 위해 Feedforward 방식의 LPA에 적용한 결과 주증폭기의 IM3 성분이 34 dBc에서 61 dBc,개선되었다. 이때 오차루프의 상쇄지수는 약 27 dB, 최종 출력 전력은 15 W로 나타났다.