• 대한물리의학회지
• /
• 제5권3호
• /
• pp.395-404
• /
• 2010

Purpose : The object of this study was to examine the effect of motor learning on brain activation depending on the method of motor learning. Methods : The brain activation was measured in 9 men by fMRI. The subjects were divided into the following groups depending on the method of motor learning: actually practice (AP, n=3) group, action observation (AO, n=3) group and motor imagery (MI, n=3) group. In order to examine the effect of motor learning depending on the method of motor learning, the brain activation data were measured during learning. For the investigation of brain activation, fMRI was conducted. Results : The results of brain activation measured before and during learning were as follows; (1) During learning, the AP group showed the activation in the following areas: primary motor area located in precentral gyrus, somatosensory area located in postcentral gyrus, supplemental motor area and prefrontal association area located in precentral gyrus, middle frontal gyrus and superior frontal gyrus, speech area located in superior temporal gyrus and middle temporal gyrus, Broca's area located in inferior parietal lobe and somatosensory association area of precuneus; (2) During learning, the AD groups showed the activation in the following areas: primary motor area located in precentral gyrus, prefrontal association area located in middle frontal gyrus and superior frontal gyrus, speech area and supplemental motor area located in superior temporal gyrus and middle temporal gyrus, Broca's area located in inferior parietal lobe, somatosensory area and primary motor area located in precentral gyrus of right cerebrum and left cerebrum, and somatosensory association area located in precuneus; and (3) During learning, the MI group showed activation in the following areas: speech area located in superior temporal gyrus, supplemental area, and somatosensory association area located in precuneus. Conclusion : Given the results above, in this study, the action observation was suggested as an alternative to motor learning through actual practice in serial reaction time task of motor learning. It showed the similar results to the actual practice in brain activation which were obtained using activation of mirror neuron. This result suggests that the brain activation occurred by the activation of mirror neuron, which was observed during action observation. The mirror neurons are located in primary motor area, somatosensory area, premotor area, supplemental motor area and somatosensory association area. In sum, when we plan a training program through physiotherapy to increase the effect during reeducation of movement, the action observation as well as best resting is necessary in increasing the effect of motor learning with the patients who cannot be engaged in actual practice.

• 한국생산제조학회지
• /
• 제20권1호
• /
• pp.114-119
• /
• 2011

There is a limit to technology of improving luminous intensity uniformity and glare, known as a weakness of existing LED lamp. Because of Using many LED, LED lamp not only waste energy but have bad effect on efficiency. Our goal is to develop security lights solution which is contented with suitable area in KS(Korean Industrial Standards) and to remove glare by combining asphere in optical system with different concept. To improve luminous intensity uniformity, a reflect mirror system was used after an aspheric optical system design for this study. We made a mirror and measured it after analysing luminance changes depend on aspheric shapes with simulation program to see if aspheric shapes effect luminance distribution. We made progress to find problems and improve them by comparing measured data and analysed data. This result of the study will contribute to industry of LED lighting through developing solution of emotional illumination of LED security lights by knowing the importance of reflectivity with this study and improving luminous intensity uniformity with solving the problem.

• 전자공학회논문지A
• /
• 제31A권9호
• /
• pp.128-138
• /
• 1994

In 1.55.mu.m DFB lasers with two non-AR mirrors, I have analyzed the effect of the sturctures of indes and/or gain gratings and mirror positions on the threshold gains, the lasing frequencies, and the beam profiles in longitudinal direction of lasers. I have obtained the optimum condition of static characteristics that ${\Delta}{\Omega}$(the phase difference betweeen index grating and gain grating is 3${\pi}$/4, $({\kappa}L)_{i}$=4~6 in case of $({\kappa}L)_{i}$=0.9 and $({\kappa}L)_{i}$=3~5 in case of $({\kappa}L)_{i}$=0.7. The modal selectivity and intensity uniformity of this optimum condition are 2~2.5 times better than those of the gain-coupled DFB lasers ${\Delta}{\Omega}$=0). The gain-coupled DFB lasers${\Delta}{\Omega}$=0) have 10$^{10) times better modal selectivity and intensity uniformity than the loss-coupled DFB lasers(TEX>${\Delta}{\Omega}$=${\pi}$).

• 한국진공학회지
• /
• 제5권4호
• /
• pp.278-283
• /
• 1996

Field terminator를 이용하여 singl path cylindrical mirror analyser를 제작하였다. 먼저 컴퓨터 모의실험을 바탕으로 CMA의 원통형 전극양단에서 fringing field effect를 최소로 하여 log-scale의 등전위면을 그대로 유지하는 terminator의 전압비와 위치 등을 구하였다. 계산된 전압을 직렬로 연결된 금속산화물저항으로 만든 voltage divider로 field terminator에 직접 인가하여 CMA의 fringing field effect를 줄이는 방법으로 개발하였다. 이 방법으로 제작된 CMA의 분해능이 $\Delta$E/E=0.4% 이상임을 확인하였다.

• 전기학회논문지
• /
• 제63권9호
• /
• pp.1281-1285
• /
• 2014

Recently, as the wide spread of smart phone, pico projector which is used at the smart phone is appeared as a portable display device. In this paper, among several pico projectors, laser beam scanner module is dealt with in which laser is used as light source, and mems-mirror is used as optical panel. In this device, screen image quality is a special issue, and blur effect is a typical adverse effect to the quality of this device. So the enhancement of this blur effect has an important factor of the quality of the device. The definition of the blur and the main source of the blur are studied and the simulation results and way of improvement are also suggested.

• 한국군사과학기술학회지
• /
• 제3권1호
• /
• pp.58-65
• /
• 2000

A target signal simulation method for passive sonar systems is introduced. The method uses multirate signal processing techniques to simulate moving target signals in the multi-path sound propagation environment by introducing Lloyd's mirror and Doppler effect. Time and frequency variation of target signal due to the target maneuvering is also considered to provide realistic ship signatures in the LOFAR gram so that the simulated target is used for sonar operator training. Synthesized target characteristics is analyzed and compared with real target signal in terms of interference pattern and frequency variation in the LOFAR gram.

• 셀메드
• /
• 제12권2호
• /
• pp.8.1-8.2
• /
• 2022

The Yangbanchum was reconstructed based on mask play that had been handed down in Goseong, Gyeongsangnam-do, Korea. Talnori, called Goseong Ogwangdae, is a Korean folk cultural heritage designated as National Important Intangible Cultural Property No. 57. This mask play provides catharsis to the audience by unraveling the hypocrisy and lies of the aristocrats through satire and humor. Our performance team, the ensemble Better Than Medicine (eBTM) used a large fan (Boochae)to create a performance that blew away anxiety and pain. Watching this performance, the performer and the audience feel the consensus of sharing emotions and send strong bonds and support to each other. This study provides that Yangbanchum dance promotes the mental health by feeling emotional sharing through vicarious satisfaction and mirror effect.

• 대한물리치료과학회지
• /
• 제28권2호
• /
• pp.65-74
• /
• 2021

Background: The purpose of this study was investigated of effect of neuromuscular electrical stimulation combined with mirror therapy on static balance, weight support and ankle movement incline with chronic stroke patients. Design: Two-group pretest-posttest design. Methods: Thirty chronic stroke patients participated in this study. The study design is a two-group pretest-posttest design. A total of 30 people participated in the study, and 15 people were each assigned to the experimental group and control group. Experimental group received neuromuscular electrical stimulation combined with mirror therapy 30 minutes, and conventional physical therapy 30 minutes. Control group received conventional physical therapy 30 minutes. Both groups were conducted 5 times a week for 4 weeks. static balance and weight support was measured by force plate and ankle movement incline was measured by goniometer. Results: As a result of comparing the static balance, weight support and ankle movement incline change between experimental group and control group, statistically significant differences were found in all variables (p<.05). In the evaluation before and after the intervention, there was a statistically significant difference in all variables in the experimental group (p<.05), but there was no statistically significant difference in the control group (p>.05). Conclusion: Neuromuscular electrical stimulation combined with mirror therapy intervention improves static balance, increase paretic side weight support and ankle movement incline in chronic stroke patients. It could be an effective intervention for improve static balance, weight support and ankle movement for chronic stroke patients.

• 대한통합의학회지
• /
• 제10권3호
• /
• pp.233-246
• /
• 2022

Purpose : The study aims to determine the effects of virtual and non-virtual realities in a normal person's mirror walk on gait characteristics. Methods : Twenty male adults (Age: 27.8 ± 5.8 years) participated in the study. Reflection markers were attached to the subjects for motion analysis, and they walked in virtual reality environments with mirrors by wearing goggles that showed them the virtual environments. After walking in virtual environments, the subjects walked in non-virtual environments with mirrors a certain distance away after taking a 5 min break. To prevent the order effect caused by the experiential difference of gait order, the subjects were randomly classified into groups of 10 and the order was differentiated. During each walk, an infrared camera was used to detect motion and the marker positions were saved in real time. Results : Comparison between the virtual and non-virtual reality mirror walks showed that the movable range of the leg joints (ankle, knee, and hip joints), body joints (sacroiliac and atlantoaxial joints), and arm joints (shoulder and wrist joints) significantly differed. Temporal characteristics showed that compared to non-virtual gaits, the virtual gaits were slower and the cycle time and double limb support time of virtual gaits were longer. Furthermore, spacial characteristics showed that compared to non-virtual gaits, virtual gaits had shorter steps and stride lengths and longer stride width and horizontally longer center of movement. Conclusion : The reduction in the joint movement in virtual reality compared to that in non-virtual reality is due to adverse effects on balance and efficiency during walking. Moreover, the spatiotemporal characteristics change based on the gait mechanisms for balance, exhibiting that virtual walks are more demanding than non-virtual walks. However, note that the subject group is a normal group with no abnormalities in gait and balance and it is unclear whether the decrease in performance is due to the environment or fear. Therefore, the effects of the subject group's improvement and fear on the results need to be analyzed in future studies.

• 헤리티지:역사와 과학
• /
• 제52권4호
• /
• pp.206-225
• /
• 2019

조선시대 문헌에서는 유리거울을 서양경(西洋鏡), 양경(洋鏡), 파리경(玻璃鏡), 파려경(玻瓈鏡), 석경(石鏡) 등 다양한 명칭으로 불렀고, 이를 경험하고 느꼈던 당시의 상황과 교역에 관한 자세한 내용을 살필 수 있다. 이를 통해 17세기 이후 청·러시아와의 교역을 중심으로 유리거울이 수입되었고, 조선 후기에 들어와 수입금지 품목에 포함되는 등 18세기에 들어와 사회적으로 큰 반향을 일으켰던 신문물로 확인되었다. 19세기에는 일상생활에 필요한 상품으로 더 크게 확대되었고, 특히 일본과의 교역이 눈에 띄게 성장하였다. 18~19세기의 유리거울은 개인이 용모를 확인하는 기본적인 용도에서 벗어나 상업적인 용도로까지 폭넓게 활용되었다. 당시 중국이나 일본을 방문했던 조선의 지식인들은 이에 관한 시각적 충격과 경험들을 글로 남겼고, 유리거울에 대한 유용함은 조선의 소비 욕구로 이어져 유리거울의 수입을 자극하였다. 이로 인해 18세기 이후 유리거울은 조선의 청동거울을 빠르게 대체하였고 유리거울을 이용한 새로운 공예품들이 제작 및 사용되기 시작하였다. 특히 실내에서 사용하는 공예품으로 일체식 유리경갑(一體式 琉璃鏡匣)을 개발해 전통적으로 사용해왔던 빗접과 함께 이용해 편리하였다. 당시 경갑의 인기는 국립중앙박물관 소장 <태평성시도(太平城市圖)>를 비롯해 조선시대 풍속화에서도 잘 볼 수 있다. 또한 중국의 기형으로 볼 수 있는 경대(鏡臺)도 조선에서 많이 제작했는데 서랍 개수와 크기, 상자 형태 등 다양한 방식으로 제작한 여러 형태의 경대를 살필 수 있다. 또한 휴대용의 작은 면경도 조선만의 미감으로 표현한 길상 문양, 장식 기법을 통해 품격 있는 공예품들로 제작되었다. 19세기에 들어와 프랑스, 네덜란드, 영국 등 유럽에서도 유리거울을 수입했지만 19세기 말 이후에는 일본식의 공예품들이 성행하였다. 일본 명치~대정시대에 유행했던 유리경대가 수입되었고 대형의 유리거울을 이용한 공예품들이 사용되었다. 이른 시기부터 있었던 경병의 경우 응접실처럼 큰 공간에 진설하거나 연회를 위해 중국·일본으로부터 수입했으며, 서양식으로 거울을 벽에 걸거나 부착해 공간의 밝기를 조절하고 외부의 풍경을 들여와 실내를 장식하는 방법이 도입되었다.