• Applied Microscopy
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• 제9권1호
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• pp.1-11
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• 1979

Electron microscopic studies were carried out to investigate the fine structure of ommatidia of the compound eyes in Meimuna mongolica D. The crystalline cone appears round, and is composed of four double-membraned cone cells and surrounded by pigment cells having many pigment granules. The rhabdom is a closed type, and is composed of four rhabdomeres Its cross section reveals lamellated microvilli which are oriented in four different directions suggesting that these represent four photoreceptive sites. The microvilli, in a cross sectional view, are hexagonal in shape with a central axis inside. There are usually eight retinular cells arranged radially from the rhabdom, but in some retinular layers seven or nine retinular cells could be observed. The cytoplasm of each retinular cell is interconnected with that of microvilli of the rhabdomere, but the appearance of this interconnection varies depending on the number of retinular cells.'The retinlilar cells neighboring the microvilli seem to have well-developed perirhabdomal vacuoles and mitochondria as well as pigment granules surrounding these vacuoles.

• 한국산학기술학회논문지
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• 제19권8호
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• pp.353-359
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• 2018

본 연구는 타각적 굴절검사에 의한 굴절이상도를 분석하여 현재 임상에서 사용되고 있는 개방형 자동굴절력계와 내부형 자동굴절력계의 성능을 평가하고자 하였다. 시력교정 및 안질환이 없는 만 18세 이상~20세 이하(평균 $19.84{\pm}0.54$세) 초기성인을 대상으로 포롭터를 활용한 자각적 굴절검사와 개방형 자동굴절력계 그리고 내부형 자동굴절력계의 순서로 굴절이상을 검사하였다. 자각적 굴절검사와 개방형 자동굴절검사의 Power vector 성분 SE, $J_0$, $J_{45}$의 상관관계는 r=0.92(p=0.00), r=0.14(p=0.43), r=0.12(p=0.47)이고 내부형 자동굴절검사는 r=0.98(p=0.00), r=0.21(p=0.22), r=0.08(p=0.65)으로 SE 성분은 통계적으로 매우 유의한 양적 상관성을 나타냈다. 그리고 SE, $J_0$, $J_{45}$ 성분에 대한 차이의 평균은 $-0.13{\pm}0.53D$(p=0.17), $+0.33{\pm}0.68D$(p=0.01), $+0.13{\pm}0.68D$(p=0.26)로 $J_0$ 성분만 통계적으로 유의한 차이를 보였고 내부형 자동굴절검사와의 SE, $J_0$, $J_{45}$ 차이값은 $-0.30{\pm}0.42D$(p=0.00), $+0.30{\pm}0.71D$(p=0.02), $-0.02{\pm}0.63D$(p=0.88)로 SE, $J_0$ 성분에서 유의한 차이가 있었다. 정확도계수와 신뢰구간은 자각적 굴절검사와 개방형 자동굴절검사에서 SE, $J_0$, $J_{45}$ 성분이 1.04(+0.91~-1.17D), 1.33(+1.66~-1.00D), 1.34(+1.46~-1.20D)이고 내부형 자동굴절검사와는 0.83(+0.52~-1.12D), 1.40(+1.69~-1.09D), 1.24(+1.21~-1.25D)로 분석되었다. 시력검사에 활용되는 개방형 내부형 자동굴절력계에 의한 측정결과는 자각적 굴절검사의 굴절이상도를 처방하는데 예비시력 검사기기로 가능하다.

• 한국산학기술학회논문지
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• 제12권12호
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• pp.5518-5524
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• 2011

사람이 서있는 동안의 안정성 감소는 낙상에 영향을 끼치는 요인 중 하나이다. 따라서 본 논문은 낙상 발생률이 높은 65세 이상의 노인여성을 대상으로 균형기능 검사를 실시하고, 성인여성의 연령대별 비교를 통해 균형능력이 노화에 따라 변화해가는 정형외과 및 신경학적 요인들을 밝혀 낙상을 예방하고자 한다. 연구 대상자는 보조기나 약물복용 없이 독립보행이 가능한 65세 이상의 신체 건강한 노인여성 10명(평균연령: 71.9세)과 성인여성 10명(평균연령: 23.2세)으로 하였다. 균형능력 평가장치(Tetrax)를 이용하여 8가지 자세에 대한 안정성 지수(Stability Index, ST), 푸리에 지수(Fourier index, F), 체중분표(Weight Distribution (%), WD), 체중분포율 지수(Weight Distribution Index, WDI), 동기화 지수(Synchronization Index, SI), 낙상율지수(fall index, FI)를 측정하였다. 그 결과, 안정성 지수(ST)는 노인여성과 성인여성간 PO를 제외한 모든 자세에서 통계적으로 유의한 차이를 나타냈다(p<.01) 푸리에지수는 낮은주파수(low, F1)에서 PO를 제외한 모든 자세에서 노인여성과 성인여성은 유의한 차이를 나타냈다(p<.01). 또한 중간낮은 주파수(middle-low, F2-F4), 중간높은주파수(middle-high, F5-F6), 높은주파수(high, F7-F8) 모두에서 노인여성이 성인여성보다 통계적으로 유의하게 높은 수치를 나타냈다. 모든 자세에서 노인여성의 체중분포율지수가 더 높게 나타났으나, PO와 PC에서만 통계적으로 유의했다. 이는 노화에 따른 생리학적 변화로 체성감각기관, 전정기관, 중추신경계등 전반적인 부분에서 능력이 저하됨에 따라 나타난 것으로 사료된다.

• 한국산학기술학회논문지
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• 제17권8호
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• pp.17-22
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• 2016

고차 QAM 시스템에 대한 자기적응 등화에서 눈 모형이 완전히 닫힌 등화 초기에 적용하여 눈 모형을 빠르게 열뿐만 아니라 정상상태 오차 레벨을 크게 낮추는 새로운 SDD 알고리즘을 제안한다. 제안 방법은 M-QAM 응용에서, 관찰에 가장 인접한 두 심볼을 추정의 기반으로 함으로써 기존 SDD의 계산 복잡성을 최소화하고, QAM 차수에 무관하게 연판정을 크게 단순화하였다. 아울러 심볼 추정에 임계 함수에 비해 오판정 회피가 우수한 시그모이드 함수를 적용, 추정의 신뢰도를 높였다. 또한 등화기 갱신을 위한 오차 발생 시 임계 함수에 의한 심볼 판정 값을 오차에 가중하여 오차 변동 범위를 확장함으로써 제안한 자기적응 등화기의 초기화 성능을 개선하였다. 결과적으로 제안 방법은 기존 SDD의 계산 복잡성과 초기화 및 수렴 특성을 현저히 개선하였다. 부가 잡음이 존재하는 다중경로 채널 조건에서 64-QAM 및 256-QAM에 대한 모의실험을 통해 CMA와 제안한 2-SDD 및 가중된 2-SDD의 두 가지 형태의 성능을 비교하고 제안 방법의 유용성을 확인하였다.

• 한국산학기술학회논문지
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• 제17권2호
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• pp.601-609
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• 2016

본 논문은 관절염을 앓고 있는 노인여성(환자군; $65.25{\pm}5.9$세, 11명)과 일반 노인여성(통제군; $64.50{\pm}7$세, 11명)을 대상으로 12주간의 수중운동(주 3회)을 실시 한 후 동적평형성과 통증(통증자각도)의 변화를 알아보고자 실시되었다. 동적평형성은 시각정보의 유무에 따라 개안 시와 폐안 시로 나누어 측정하였다. 12주간의 수중운동에 따른 개안 시 동적평형성은 관절염 환자군(p<.001)과 통제군(p<.05)에서 유의하게 향상되었고, 폐안 시 관절염 환자군에서도 유의하게 향상된 결과를 보였다(p<.05). 또한, 통증자각도(VAS) 평가에 의한 통증 변화는 관절염 환자군의 10요인(푹신한 의자에 똑바로 앉아있기 힘든가, p<.01), 11요인(누워있을 때 통증이 덜해지는가, p<.05), 12요인(통증때문에 일상생활에 지장이 있는가, p<.05), 13요인(통증 때문에 직장일 또는 집안일에 지장이 있는가, p<.01)에서 유의한 통증 감소가 나타났다. 본 연구 결과를 통해 12주간의 수중 운동은 골관절염 노인 환자에게 개안 시와 폐안 시 모두 동적평형 능력을 향상 시키고, 일부 통증요인 감소에 효과적인 운동임을 알 수 있었다.

• 한국전문물리치료학회지
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• 제7권2호
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• pp.35-54
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• 2000

The purposes of this study were to assess variation of body sway prior to and after submaximal treadmill exercise; to determine the time course of the effects of a fatiguing performed on a treadmill on body sway; and to compare position sense prior to and after exercise in order to assess any variance in proprioception caused by submaximal treadmill exercise. The subjects were twenty-four healthy men in their twenties. They stood barefoot on the Kinesthetic Ability Training Balance Platform to measure body sway. Control trials were performed with eyes alternately open and closed. In the eyes open condition, they were asked to look at a target placed at eye level 1 m in front them. A total of 10 trials, each lasting 20 seconds, were performed. After this series of trials, position sense was measured. Subjects then exercised on the treadmill until 85% of each person's maximal heart rate was reached. The first series of postural sway measurements began immediately after this exercise. The second identical series of postural sway trials was performed at approximately 10 minutes after exercise. The third series was performed approximately 20 minutes after exercise. This allowed approximately 5 minutes of rest between each experimental series. Position sense was measured at approximately 15 and 25 minutes after exercise. The results were as follows: 1) There was a significant increase in body sway after submaximal treadmill exercise compared to pre-exercise values under both visual conditions (p<.05). 2) After submaximal treadmill exercise, under the eyes open condition, the mean value of body sway was significantly increased after both the first and second series (p<.05). Under the eyes closed condition, the mean value of body sway increased significantly after the first series but decreased significantly after the third series (p<.05). 3) Position sense, measured repeatedly after submaximal treadmill exercise, did not change significantly with respect to pre-exercise values (p>.05). These results suggest that fatigue induced by submaximal treadmill exercise produced an increase in body sway in young healthy subjects with or without visual input, but the increase appeared to be lasting less than 15 minutes. No significant change in position sense suggested that proprioception was unaffected by submaximal treadmill exercise-induced fatigue.

• 생물정신의학
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• 제2권2호
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• pp.257-265
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• 1995

선형적이고 정적인 뇌파 분석의 한계를 극복하고자 비선형적이고 동적인 접근방식인 혼돈이론을 이용하여 정신분열병환자 16명, 양극성 정동장애 10명, 주요 우울증 6명 및 정상 대조군 12명을 대상으로 뇌파 분석을 시도하고, 객관적인 혼돈 연구의 도입에 있어서 고려되어야 할 문제점을 살펴보고자 하였다. 각 질환에서의 상관차원의 분포가 정상대조군보다 개인에 따른 차이가 크다는 것을 알 수 있었고, 대체적으로 측두엽 부위에서 상관차원이 크게 나타나는 경향이 있었다. 이러한 결과와 관련하여 대상환자군의 특성, 혼돈이론을 뇌파분석에 이용할 때의 주의점등에 대하여 토론하였다.

• 대한물리의학회지
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• 제6권3호
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• pp.293-301
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• 2011

Purpose : The purposes of this study were to investigate the age-related difference in balance ability in the elderly over 65 years and to verify the clinical usefulness of the functional reach test (FRT) for balance evaluation of the elderly through the sensory organization test (SOT). Methods : The subjects were forty-six community dwelling elderly people over 65 years old in order to verify the correlation of balance measures and to compare the balance ability. Balance was measured using the FRT and the six sub-equilibrium scores and the composite equilibrium score of the SOT. Pearson's product correlation coefficient was used to evaluate the relationships among these measurements of balance. Results : There was a significant difference in functional reach by age in the elderly (p<.01). There was a significant negative correlation between the FRT and the age of the elderly (r=-.396, p<.01). There was also significant high positive correlation between the FRT and the eye closed sway surface (EC/SS) (r=.789, p<.01), and composite equilibrium score (r=.548, p<.01) of the SOT. Conclusion : Thus, it is possible to use the FRT as a quantitative measure of balance, rather than the SOT, which is more expensive and complicated to evaluate elderly people. According to the results of this study, the use of the FRT is required clinically to objectively measure the balance of elderly people in the future.

• 대한의용생체공학회:의공학회지
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• 제28권2호
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• pp.258-264
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• 2007

Spatiotemporal changes of brain rhythmic activity at a certain frequency have been usually monitored in real time using scalp potential maps of multi-channel electroencephalography(EEG) or magnetic field maps of magnetoencephalography(MEG). In the present study, we investigate if it is possible to implement a real-time brain activity monitoring system which can monitor spatiotemporal changes of cortical rhythmic activity on a subject's cortical surface, neither on a sensor plane nor on a standard brain model, with a high temporal resolution. In the suggested system, a frequency domain inverse operator is preliminarily constructed, considering the individual subject's anatomical information, noise level, and sensor configurations. Spectral current power at each cortical vertex is then calculated for the Fourier transforms of successive sections of continuous data, when a single frequency or particular frequency band is given. An offline study which perfectly simulated the suggested system demonstrates that cortical rhythmic source changes can be monitored at the cortical level with a maximal delay time of about 200 ms, when 18 channel EEG data are analyzed under Pentium4 3.4GHz environment. Two sets of artifact-free, eye closed, resting EEG data acquired from a dementia patient and a normal male subject were used to show the feasibility of the suggested system. Factors influencing the computational delay are investigated and possible applications of the system are discussed as well.

• 한국의류학회지
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• 제21권5호
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• pp.946-955
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• 1997

The purpose of this study is to present the aesthetic values of the Korean traditional costume for developing 'Korean' fashion design can be accepted in general in the modern times. For this purpose, documentary studies about the aesthetic values of the Korean traditional art and Korean traditional costume were preceded. And the perception of the Korean traditional costume were studied according to Belong's two criteria, body priority/ clothes priority and open/closed. Next, the aesthetic values of the Korean traditional costume were re-defined. The results can be summarized as follows; 1) The aesthetic values of the Korean traditional art are the beauty of nature, the purity, and the pleasantry. As the beauty of nature is the important one, the purity is caused by the love of nature. The pleasantry is as a way of expression. 2) The aesthetic values of the Korean traditional costume through the documentary studies stand for as the beauty of nature, the purity, the beauty of evil's eye, the beauty of symbolism, the beauty of personality, the beauty of tragedy and the beauty of tradition. 3) Korean traditional costume are perceived as clothes priority and open. 4) The aesthetic values of the Korean traditional costume can be re-defined as the beauty of nature, the purity, and the pleasantry. The beauty of nature comes from the 'natural' look, the exposure of the fabric as itself and the organic lines of the Korean traditional costume. The purity comes from the geometrical squared clothing form of Korean traditional costume which doesn't revive the human body form. The Pleasantry is seen the colors and motifs of costumes that have the human's hope and incantation and the exaggeration and distortion of human body form.