소금 농도와 삭힘 시간에 따른 깻잎 장아찌의 전처리 조건의 최적화

이종미,이혜란,남상민 한국식생활문화학회 2002 韓國食生活文化學會誌 Vol.17 No.1

Jangachi(salted and fermented vegetable) has been made by Korean traditionally using several kinds of vegetables, which is a good source of variety of nutrients and vitamins. There are many methods for making Jangachi. Generally soy sauce Jangachi is made through two steps. First, as a pretreatment, vegetables are soaked in salt water. Second, soaked vegetables are fermented in various ingredients like soy sauce, sugar, garlic, ginger and so on. This study was performed to observe changes in contents of chemical components and sensory evaluation of pretreated perilla leaf. Perilla leaf was soaked in water with different levels of salt concentration(2, 5 and 8 %) and soaking time(1, 3 and 5 days). The optimal level of salt and soaking time was determined with the results of sensory evaluation by response surface methodology and analysis of composition. The moisture contents decreased as the levels of salt and soaking time increased. The moisture content of untreated sample was 87.5 % and when soaked for 5 days in the water of 8 % salt concentration, it became 78.27 %. pH of Perilla leaf was high in high levels of salt concentration and short soaking time. Total acidity was so opposite to pH that was low in high levels of salt concentration and short soaking time. In the water of 8 % salt concentration, total acidity was 0.14 when soaked for 1 day, 0.20 % for 3 days and 0.30 % for 5 days. Salt contents became greater as the soaking time increased. As the results of puncture test, soaked Perilla leaf's toughness increased as the levels of salt increased and soaking time decreased. Among the sensory attributes, greenness increased as the levels of salt concentration increased when soaked for more than 3 days. Saltiness and bitterness became greater as the levels of salt concentration increased. Perilla flavor decreased with the short soaking time. Off-flavor increased with the increased levels of soaking time and decreased salt concentration when soaked for more than 3 days. Toughness decreased as the levels of soaking time increased. Crispness increased with the increased levels of salt concentration. The condition of pretreated Perilla was optimum when it soaked for 42 hours in 4 % salt concentration.

SPECT/CT의 획득시간 증감에 따른 방사능농도 추정치의 변화

김지현,이주영,손현수,박훈희,Kim, Ji-Hyeon,Lee, Jooyoung,Son, Hyeon-Soo,Park, Hoon-Hee 대한핵의학기술학회 2021 핵의학 기술 Vol.25 No.2

Purpose SPECT/CT was noted for its excellent correction method and qualitative functions based on fusion images in the early stages of dissemination, and interest in and utilization of quantitative functions has been increasing with the recent introduction of companion diagnostic therapy(Theranostics). Unlike PET/CT, various conditions like the type of collimator and detector rotation are a challenging factor for image acquisition and reconstruction methods at absolute quantification of SPECT/CT. Therefore, in this study, We want to find out the effect on the radioactivity concentration estimate by the increase or decrease of the total acquisition time according to the number of projections and the acquisition time per projection among SPECT/CT imaging conditions. Materials and Methods After filling the 9,293 ml cylindrical phantom with sterile water and diluting 99mTc 91.76 MBq, the standard image was taken with a total acquisition time of 600 sec (10 sec/frame × 120 frames, matrix size 128 × 128) and also volume sensitivity and the calibration factor was verified. Based on the standard image, the comparative images were obtained by increasing or decreasing the total acquisition time. namely 60 (-90%), 150 (-75%), 300 (-50%), 450 (-25%), 900 (+50%), and 1200 (+100%) sec. For each image detail, the acquisition time(sec/frame) per projection was set to 1.0, 2.5, 5.0, 7.5, 15.0 and 20.0 sec (fixed number of projections: 120 frame) and the number of projection images was set to 12, 30, 60, 90, 180 and 240 frames(fixed time per projection:10 sec). Based on the coefficients measured through the volume of interest in each acquired image, the percentage of variation about the contrast to noise ratio (CNR) was determined as a qualitative assessment, and the quantitative assessment was conducted through the percentage of variation of the radioactivity concentration estimate. At this time, the relationship between the radioactivity concentration estimate (cps/ml) and the actual radioactivity concentration (Bq/ml) was compared and analyzed using the recovery coefficient (RC_Recovery Coefficients) as an indicator. Results The results [CNR, radioactivity Concentration, RC] by the change in the number of projections for each increase or decrease rate (-90%, -75%, -50%, -25%, +50%, +100%) of total acquisition time are as follows. [-89.5%, +3.90%, 1.04] at -90%, [-77.9%, +2.71%, 1.03] at -75%, [-55.6%, +1.85%, 1.02] at -50%, [-33.6%, +1.37%, 1.01] at -25%, [-33.7%, +0.71%, 1.01] at +50%, [+93.2%, +0.32%, 1.00] at +100%. and also The results [CNR, radioactivity Concentration, RC] by the acquisition time change for each increase or decrease rate (-90%, -75%, -50%, -25%, +50%, +100%) of total acquisition time are as follows. [-89.3%, -3.55%, 0.96] at - 90%, [-73.4%, -0.17%, 1.00] at -75%, [-49.6%, -0.34%, 1.00] at -50%, [-24.9%, 0.03%, 1.00] at -25%, [+49.3%, -0.04%, 1.00] at +50%, [+99.0%, +0.11%, 1.00] at +100%. Conclusion In SPECT/CT, the total coefficient obtained according to the increase or decrease of the total acquisition time and the resulting image quality (CNR) showed a pattern that changed proportionally. On the other hand, quantitative evaluations through absolute quantification showed a change of less than 5% (-3.55 to +3.90%) under all experimental conditions, maintaining quantitative accuracy (RC 0.96 to 1.04). Considering the reduction of the total acquisition time rather than the increasing of the image acquiring time, The reduction in total acquisition time is applicable to quantitative analysis without significant loss and is judged to be clinically effective. This study shows that when increasing or decreasing of total acquisition time, changes in acquisition time per projection have fewer fluctuations that occur in qualitative and quantitative condition changes than the change in the number of projections under the same scanning time conditions. SPECT/CT는 보급 초기에 뛰어난 보정방법과 융합영상을 기반으로 한 정성적 기능이 주목받았고, 최근 동반진단치료(Theranostics)등의 도입으로 그 정량적 기능에 대한 관심과 활용이 증가되는 추세이다. PET/CT와 달리 SPECT/CT의 절대 정량화는 조준기의 종류, 검출기 회전과 같은 조건들이 영상획득과 재구성 방법 등에 까다로운 요소로 작용하고 있다. 따라서 본 연구에서는 SPECT/CT 촬영조건 중 투영상수와 투영상당 획득시간에 따른 총 획득시간(검사시간)의 증·감이 방사능농도 추정치에 미치는 영향을 알아보고자 한다. 부피 9,293 ml의 원통형 팬텀에 멸균수를 가득 채운 후 99mTcO4- 91.76 MBq를 희석하여 총 획득시간 600 sec(10 sec/frame × 120 frames, matrix size 128 × 128)의 조건으로 기준영상을 촬영하였고, 체적감도와 교정인자를 확인하였다. 기준영상을 중심으로 총 획득시간을 60(-90%), 150(-75%), 300(-50%), 450(-25%), 900(+50%), 1200(+100%) sec/frame으로 증·감시켜 비교영상을 획득하였고, 각 영상별 세부조건은 투영상당 획득시간(sec/frame)을 1.0, 2.5, 5.0, 7.5, 15.0, 20.0 sec/frame(투영상수 120frames 고정)로, 투영상수를 12, 30, 60, 90, 180, 240 frames(투영상당 획득시간 10 sec/frame 고정)로 설정하였다. 획득된 각 영상에서 관심체적을 통하여 측정한 계수를 바탕으로 정성적 평가로서 CNR(Contrast to Noise Ratio)의 변동률(%)을 확인하였고, 방사능농도 추정치의 변동률(%)을 통해서는 정량적 평가를 시행하였다. 이때 방사능농도 추정치(cps/ml)와 실제 방사능농도(Bq/ml)의 관계는 회복계수(RC_Recovery Coefficients)를 지표로 비교·분석하였다. 투영상수 변화에 따른 결과[CNR 변동률(%), 방사능농도 추정치 변동률(%), RC]는 총 획득시간 증감률(%) -90%에서 [-89.5%, +3.90%, 1.04], -75%에서 [-77.9%, +2.71%, 1.03], -50%에서 [-55.6%, +1.85%, 1.02], -25%에서 [-33.6%, +1.37%, 1.01], +50%에서 [+33.7%, +0.71%, 1.01], +100%에서 [+93.2%, +0.32%, 1.00]이었으며, 투영상당 획득시간 변화에 따른 결과는 총 획득시간 증감률(%)-90%에서 [-89.3%, -3.55%, 0.96], -75%에서 [-73.4%, -0.17%, 1.00], -50%에서 [-49.6%, -0.34%, 1.00], -25%에서 [-24.9%, 0.03%, 1.00], +50%에서 [+49.3%, -0.04%, 1.00], +100%에서 [+99.0%, +0.11%, 1.00]이었다. SPECT/CT에서 총 획득시간의 증·감에 따라 획득된 총 계수와 그에 따른 영상품질(CNR)은 비례하여 변화하는 양상을 보였지만, 절대 정량화를 통한 정량적 평가에서는 모든 실험조건에서 5% 미만(-3.55에서 +3.90%)의 변화를 보여 큰 영향을 받지 않고 정량적 정확성(RC 0.96에서 1.04)을 유지하였다. 검사시간의 증가보다는 단축을 우선하여 고려하였을 때 총 획득시간 감소는 정성적 기능에 있어서 기존에도 배제할 수 없었던 사항이지만 정량적 기능은 큰 손실 없이 적용 가능하여 임상적으로 실효성이 있다고 판단된다. 다만 총 획득시간의 증·감 시 동일한 검사시간이라면 투영상수의 변경보다는 투영상당 획득시간의 변경이 정성적, 정량적으로 조건변화에 따른 변동 폭이 적은 것으로 나타났다.

유역 집중시간 및 저류상수의 이론적 배경과 경험식

이지호,유철상,신지예 한국수자원학회 2013 한국수자원학회논문집 Vol.46 No.2

본 연구에서는 유역 집중시간과 저류상수의 이론적 배경을 바탕으로 적절한 경험식의 형태를 제시하고 기존의 경험식의 형태와 비교·평가하였다. 추가로, 제시된 경험식의 형태를 이용하여 충주댐 유역의 집중시간 및 저류상수의 경험식을 유도하고, 유도된 경험식과 기존의 경험식들을 비교하였다. 그 결과를 정리하면 다음과 같다. (1) 유역의 집중시간에 대한 경험공식의 형태는 유로연장의 제곱에 비례하고 유로경사에 반비례하는 형태로 나타난다. (2) 저류상수는 집중시간에 비례하는 형태로 나타난다. (3) 기존 매개변수에 관한 경험식을 검토한 결과, 집중시간의 경우에는 Kirpich 공식, Kraven (I) 공식, Kraven (II) 공식, California DoT 공식, Kerby 공식, SCS 공식 및 Morgali and Linsley 공식 등이 이러한 이론적 배경을 잘 따르고 있는 것으로 나타난다. 저류상수의 경우, Clark 공식, Russell 공식, Sabol 공식 및 정성원 공식 등이 본 저류상수와 집중시간의 비례관계를 매우 잘 만족하는 것으로 나타난다. (4) 기존의 경험식을 충주댐 유역에 적용한 결과, 집중시간의 경험식 중 정성원 공식, 윤태훈 등 공식, Kraven (I) 공식 및 Kraven (II) 공식은 추정한 집중시간과 비교적 유사한 결과를 보였으나, Rziha 공식은 비정상적인 결과를 나타내는 것으로 나타났다. 저류상수의 경우에는 윤석영과 홍일표 공식, 정성원 공식, 이정식 등 공식 및 윤태훈 등 공식이 어느 정도 합리적인 결과를 보인 반면, Sabol 공식의 경우에는 비정상적인 결과가 유도되었다. 결론적으로 국내의 집중시간 및 저류상수에 대한 경험공식이 국내 유역의 특성을 잘 반영하는 것으로 나타났다. This study proposes proper forms of empirical formulas for the concentration time and storage coefficient based on their theoretical backgrounds and evaluates several existing empirical formulas by comparing them with the formula proposed in this study. Additionally, empirical formulas for the concentration time and storage coefficient of the Chungju Dam basin were derived using the forms proposed by considering their theoretical backgrounds, and compared with exiting empirical formulas. The results derived are summarized as follows. (1) The concentration time of a basin is proportional to the square of the main channel length, but inversely proportional to the channel slope, as the flood flow is generally turbulent. (2) The storage coefficient is proportional to the concentration time. (3) The comparison results with existing empirical formulas for the concentration time indicates that the empirical formulas like the Kirpich, Kraven (I), Kraven (II), California DoT, Kerby, SCS, and Morgali & Linsley are in line with the form proposed in this study. Among existing empirical formulas for the storage coefficient, the Clak, Russell, Sabol and Jung are found to be well matched to this study. (4) The application results to Chungju Dam basin indicates that among empirical formulas for the concentration time, the Jung, Yoon, Kraven (I), and Kraven (II) show relatively similar results to the observed in this study, but the Rziha shows abnormal results. Among the empirical formulas for the storage coefficient, the Yoon and Hong, Jung, Lee, and Yoon show somewhat reasonable results, but the Sabol shows abnormal results. In conclusion, the empirical formulas for the concentration time and storage coefficient developed in Korea are found to reflect the basin characteristics of Korea better.

다중이용업소 방문자 그룹의 피난 시 혈중알코올농도별 반응시간 비교

오지석(Oh, Ji-Seok),오륜석(Oh, Ryun-Seok),최준호(Choi, Jun-Ho) 대한건축학회 2021 대한건축학회논문집 Vol.37 No.7

In order to evaluate the risk of fire in multi-use establishments with a higher occupancy rate than other buildings, data on the evacuation behavior (evacuation time, walking speed, etc.) of drinkers are necessary. However, since the data on the evacuation behavior of drinkers are not generalized, fire risk assessments are being carried out on the evacuation behavior data of non-drinkers. Therefore, the results of assessments cannot be fully trusted. In this study, a real experiment was conducted to analyze the evacuation behavior of South Korean adults when they are drunken. In the experiment, the experimental participants were classified into groups according to the levels of drinking and the amounts of required time by group were measured by evacuation stage (recognition time, activity time, pre-travel time and response time). According to the experimental results, the required time of the group with the largest volume of drink was about 11.11 times longer in the recognition time, about 3.02 times in the activity time, and about 1.63 times longer in the pre-travel time than that of the group with the smallest volume of drink. However, it was found that their response time was shortened by about 0.5 times. When the experimental results were put together, in general, the amounts of required time by evacuation stage increased as the volume of drink increased.

폭 함수를 기반으로 한 Clark 모형의 매개변수 추정

박상현,김주철,정관수 한국수자원학회 2013 한국수자원학회논문집 Vol.46 No.6

본 연구에서는 Clark 모형의 시간-면적곡선의 구성 방법과 적용성을 검토하고 모멘트 원리에 의한 도달시간, 저류상수를 합리적으로 산정하기 위한 방법론을 고찰해 보았다. 격자 기반으로 폭 함수를 구성하고 운동과정을 순수 이류현상으로 가정하여 시간-면적곡선으로 사용하였다. 또한 도달시간과 저류상수는 모멘트 법의 원리에 따라 Clark 모형 구조에 적용하여 해석적으로 산정할 수 있는 방법을 제시하였다. 적용성 검토를 위해 (1) HEC-1에서 기본적으로 제공하는 좌우 대칭형상인 무차원 시간-면적곡선을 적용하고 매개변수 산정은 관측유출수문곡선과 계산된 유출수문곡선의 오차를 최소화하는 HEC-1의 최적화 기법 사용, (2) HEC-1에 폭 함수 기반의 시간-면적곡선을 적용하고 매개변수 산정은 HEC-1의 최적화 기법 사용, (3) 폭 함수 기반의 시간-면적곡선을 이용하여 모멘트 원리에 따라 매개변수를 직접 산정하는 방법을 적용하였다. 방법별로 산정된 Clark 모형의 매개변수들을 HEC-1을 이용하여 직접유출량을 산정하고 관측 직접유출량과 비교하여 얻은 결과는 다음과 같다. (1) 정량적으로 비교하기 위해 산정한 첨두유량과 첨두발생 시간의 상대오차 및 효율계수 E(Efficiency Coefficient)를 비교한 결과, 시간-면적곡선을 폭 함수로 대체하여 HEC-1으로부터 추정된 매개변수가 관측값을 잘 반영하였다. (2) Clark 모형의 올바른 적용을 위해서는 HEC-1에서 기본적으로 제공하는 좌우 대칭형상인 무차원 시간-면적곡선보다는 적용 대상유역의 배수구조가 적절하게 반영된 시간-면적곡선의 사용이 합리적일 것으로 판단된다. (3) 본 연구 방법은 첨두유량과 첨두시간의 상대오차 범위와 재현정도를 나타내는 효율계수를 비교하여 볼 때 대체로 양호하게 모의되었고, 대상유역별 유량측정성과인 하천평균유속과 비교했을 때 본 연구 방법이 다소 실제 유속에 접근하고 있음을 확인하였다. (4) 본 연구에서 모멘트 원리를 기반으로 제안한 매개변수 추정을 위한 방법은 유역의 이류현상과 저류현상을 정량적으로 계량할 수 있는 효율적인 관계식으로 사용할 수 있음을 확인하였다. (5) 본 방법에 의해 계산된 수문곡선이 대부분 관측수문곡선의 우측으로 왜곡되고 첨두유량은 과소평가 되는 것을 보이고 있다. 이것은 평균과 분산만을 고려하여 유역을 하나의 평균이송속도로 모의한 본 연구의 한계점으로 판단된다. 만약 모멘트의 왜곡도를 고려하고 유역을 지표면과 하천으로 나누어 평균이송속도를 모의한다면 물리적인 특성을 충분히 반영하여 매개변수를 추정 할 수 있을 것으로 판단된다. This paper presents the methodology for construction of time-area curve via the width function and thereby rational estimation of time of concentration and storage coefficient of Clark model within the framework of method of moments. To this end time-area curve is built by rescaling the grid-based width function under the assumption of pure translation and then the analytical expressions for two parameters of Clark model are proposed in terms of method of moments. The methodology in this study based on the analytical expressions mentioned before is compared with both (1) the traditional optimization method of Clark model provided by HEC-1 in which the symmetric time-area curve is used and the difference between observed and simulated hydrographs is minimized (2) and the same optimization method but replacing time-area curve with rescaled width function in respect of peak discharge and time to peak of simulated direct runoff hydrographs and their efficiency coefficient relative to the observed ones. The following points are worth of emphasizing: (1) The optimization method by HEC-1 with rescaled width function among others results in the parameters well reflecting the observed runoff hydrograph with respect to peak discharge coordinates and coefficient of efficiency; (2) For the better application of Clark model it is recommended to use the time-area curve capable of accounting for irregular drainage structure of a river basin such as rescaled width function instead of symmetric time-area curve by HEC-1; (3) Moment-based methodology with rescaled width function developed in this study also gives rise to satisfactory simulation results in terms of peak discharge coordinates and coefficient of efficiency. Especially the mean velocities estimated from this method, characterizing the translation effect of time-area curve, are well consistent with the field surveying results for the points of interest in this study; (4) It is confirmed that the moment-based methodology could be an effective tool for quantitative assessment of translation and storage effects of natural river basin; (5) The runoff hydrographs simulated by the moment-based methodology tend to be more right skewed relative to the observed ones and have lower peaks. It is inferred that this is due to consideration of only one mean velocity in the parameter estimation. Further research is required to combine the hydrodynamic heterogeneity between hillslope and channel network into the construction of time-area curve.

COMPARISON OF FLUX AND RESIDENT CONCENTRATION BREAKTHROUGH CURVES IN STRUCTURED SOIL COLUMNS

Kim, Dong-Ju Korean Society of Soil and Groundwater Environment 1997 지하수토양환경 Vol.2 No.2

오염물질 이동현상 연구에서는 침출수 혹은 잔존수농도 형태가 사용되는데 이의 선택은 모니터링 방법에 의존하게 된다. 파과곡선 실험에서 모니터링 농도 형태에 관한 선택은 임의적이며, 각 농도 형태에서 얻어진 운송 파라미터들은 동등하며 다공성매질의 수리적 특성을 각각 대표하는 것으로 알려져왔다. 그러나, 현장상태의 구조적 발달을 보이는 토양에서는 농도 형태별 운송계수의 동등성이 의문시 된다. 본 연 구에서는 불교란 현장시료(직경 20cm, 높이 20cm)에 대하여 두가지 농도 형태에 의한 파과곡선 실험을 시행하므로써 모니터링 방법에 따른 농도 형태와 그에 따른 운송 파라미터들을 비교분석 하였다. 침출수 농도와 잔존수 농도는 토양상부에서 20cm와 loom 떨어진 지점에서 EC-meter와 TDR 을 이용하여 각각 측정하였다. 연구결과, 침출수 농도는 잔존수 농도보다 첨두농도가 훨씬 높게 그리고 첨두농도의 운송시간이 짧게 나타났음을 알 수 있었다. 따라서 침출수농도곡선으로부터 추정된 운송파 라미터들은 잔존수농도곡선으로부터 추정된 수치들과 상당한 차이를 보였으며 그 차이는 CLT 모델보다 CDE 모델에서 더 크게 나타났다. 특히 CDE 모델에서는 침출수곡선으로부터 도출된 계수값들이 잔존수곡선으로부터 도출된 계수값들보다 훨씬 크게 나타났다. 이는 구조토양내에 존재하고 있는 대공극을 통한 오염물질 우회통과와 평형조건에서의 CDE 모델이 연구대상토양에서의 오염물질 이동현상을 표현하는데 부적합하였기 때문인 것으로 사료된다. 분자 분산에 대한 동수리학적 확산의 비와 Peclet number와의 상관관계를 나타내는 도표영역에서 두가지 농도는 모두 역학적 확산이 오염물질 운송을 좌우하는 영역에 속하였다. 그러나 분자분산은 토양내 대공극부분보다 matrix 부분에서의 오염물질 확산에 더 많은 기여를 하는 것으로 나타났으며 이는 공극유속과 확산계수사이에 존재하는 비선형성에 기인하기 때문인 것으로 사료된다. In many solute transport studies, either flux or resident concentration has been used. Choice of the concentration mode was dependent on the monitoring device in solute displacement experiments. It has been accepted that no priority exists in the selection of concentration mode in the study of solute transport. It would be questionable, however, to accept the equivalency in the solute transport parameters between flux and resident concentrations in structured soils exhibiting preferential movement of solute. In this study, we investigate how they differ in the monitored breakthrough curves (BTCs) and transport parameters for a given boundary and flow condition by performing solute displacement experiments on a number of undisturbed soil columns. Both flux and resident concentrations have been simultaneously obtained by monitoring the effluent and resistance of the horizontally-positioned TDR probes. Two different solute transport models namely, convection-dispersion equation (CDE) and convective lognormal transfer function (CLT) models, were fitted to the observed breakthrough data in order to quantify the difference between two concentration modes. The study reveals that soil columns having relatively high flux densities exhibited great differences in the degree of peak concentration and travel time of peak between flux and resident concentrations. The peak concentration in flux mode was several times higher than that in resident one. Accordingly, the estimated parameters of flux mode differed greatly from those of resident mode and the difference was more pronounced in CDE than CLT model. Especially in CDE model, the parameters of flux mode were much higher than those of resident mode. This was mainly due to the bypassing of solute through soil macropores and failure of the equilibrium CDE model to adequate description of solute transport in studied soils. In the domain of the relationship between the ratio of hydrodynamic dispersion to molecular diffusion and the peclet number, both concentrations fall on a zone of predominant mechanical dispersion. However, it appears that more molecular diffusion contributes to the solute spreading in the matrix region than the macropore region due to the nonliearity present in the pore water velocity and dispersion coefficient relationship.

Exposure of BALB/3T3 fibroblast cells to temporal concentration profile of toxicant inside microfluidic device

신현종,Sanjeev Kumar Mahto,김재현,이석우 한국바이오칩학회 2011 BioChip Journal Vol.5 No.3

This work describes a simple method that generates temporal concentration profiles of chemicals inside a microfluidic channel and exposes cultured cells to chemicals in order to mimic the exponential clearance curve of chemicals in the human body. The device fabricated with a poly (dimethylsiloxane)(PDMS) replica mold and a glass substrate was used to create the microfluidic channels. The fluid streams inside the channels were controlled by programmable syringe pumps. By controlling the relative flow rates of the fluidic inlets using separate syringe pumps, the resulting composition of the inlets that feed the concentration generator zone can be controlled to generate temporal profiles of chemicals in the observation zone. The concentration profiles of fluorescent dye were confirmed by analyzing the time-lapse fluorescence images. Finally, a temporal concentration profile of toxic cadmium solution with exponential clearance curve was exposed to BALB/3T3 fibroblast cells confluently cultured inside a microfluidic device for 3 h, and the behavior of the cells was monitored using a time-lapse microscope. The relative concentration of reactive oxygen species inside the exposed cells was measured indirectly by using a fluorescent probe to assess the degree of cell death. The method developed in this work offers a convenient way of controlling the concentration of chemicals inside microfluidic channels, and enables time-dependent exposure of chemicals to cells and monitoring of the behavior of cells for biological research applications.

집중력, 청각반응속도, 순발력이 민첩성에 미치는 영향

김미경,남지윤,노수영,한동욱,Kim, Mi-Kyoung,Nam, Ji-Yoon,Noh, Su-Yeong,Han, Dong-Wook 대한물리치료과학회 2012 대한물리치료과학회지 Vol.19 No.3

Background : The purpose of this study was to investigate the relationship between an agility and a concentration, an auditory reaction time and a muscle power. Methods : Twenty one healthy female college students who were 20-21 years participated in the experiment; after being introduced to the methods, they voluntarily signed a consent form. And they received several test related with this study; side step test for an agility, Harris & Harris test for a concentration, brain auditory evoked potential test for an auditory reaction time and vertical jump test for a muscle power. Result : There was no relationship between the agility and the concentration and the auditory reaction time. However, the muscle power related with the agility significantly. Conclusion : In conclusion, these findings suggest that a muscle power training is a good way to promote an agility. So, we can find out that, in an player who requires an agility, a muscle power training is the most important way for promoting an agility than a concentration training or an auditory reaction time training.

시선의 고정과 도약 동공지표에 나타난 성별 주시시간 특성

이정호,김종하 한국실내디자인학회 2018 한국실내디자인학회논문집 Vol.27 No.1

This research is to analyze the change of pupil size in gender through the eye-tracking experiment in large complex cultural space. It is meaningful that figured out the common characteristics and differences from gender observation characteristics. Through this research, the analyzed results of the observation time measurement that appeared from the fixation and saccades pupil indicator able to define as follows. Firstly, it was suggested that there were differences between each gender and participants through extract pupil size that can be the standard examples for the case from male and female and the process of extracting the relative pupil size change on the hourly range. From the specific time range, it was possible to indicate bending characteristics and reversal phenomena of Fixation and Saccades. Second, the result was found equally from both male and female group that the rapid increment of pupil size at initial time range immediately after the eye-tracking experiment has been initiated. This can be considered to actively accepting the stress given by the subject through the extended pupil after 10 seconds that compare to indicated very low pupil size between 0 to 10 seconds after starting the experiment. Third, meanwhile 0 to 10 seconds after initial observation are the time of sudden change in the pupil size, therefore these time range data cannot be regarded as observed in the appropriate condition. Thus, it able to define the highest times of emotional processing for male as 10 to 80 seconds, and for female as 10 to 70 seconds. There was no definition of the time range data for observation experiment from previous research, this data can be considered to stable time to observation through the pupil extension. Therefore, it is possible to set suitable time of observation experiment to be around 70 to 80 seconds exclude initial experiment time. 본 연구는 대형복합문화공간을 대상으로 시선추적 실험을 통해 성별에 나타난 동공크기 변화를 분석하였다. 성별 주시특성으로 공통적 특성과 차이점을 밝혔다는 점에서 의미가 있다. 이상의 연구를 통해서 Fixation과 Saccades 동공지표에 나타난 주시시간 측성을 분석한 결과는 다음과 같이 몇 가지로 정의할 수 있다첫째, 남녀 사례별 기준이 되는 동공크기를 추출하고 시간범위별 상대적 동공크기 변화를 추출하는 과정을 통해 성별, 참여자별로 주시특성에 차이가 있음을 제시하였다. 특정 시간범위를 기점으로 Fixation과 Saccades의 굴곡특성과 역전현상을 발견할 수 있었다. 둘째, 시선추적 실험을 시작한 직후의 초기 시간범위[1→2]에서 급격한 동공크기의 상승이 남녀 참여자그룹에서 공동으로 나타났다. 이것은 실험을 시작한 첫 시간범위0초~10초 사이에는 아주 낮은 동공크기를 가진 반면, 10초가 지난 이후에 확장된 동공을 통해 주시 대상이 주는 자극을 적극적으로 수용한 것으로 볼 수 있다. 세째, 한편 최초 주시가 이루어진 0초~10초까지는 급격한 동공크기 변화가 일어난 시간으로, 이 시간범위의 데이터는 적절한 상태에서 주시를 한 것으로 볼 수 없다. 따라서 감정적인 처리과정이 높은 시간을 남자는 10초~80초까지, 여자는 10초~70초까지로 볼 수 있다. 기존 연구에서는 주시실험을 어느 정도의 시간으로 할 것인가에 대한 정의가 없었는데, 이 시간범위가 동공확대를 통해 주시를 안정적으로 한 시간으로 볼 수 있다. 따라서 초기 실험시간을 제척한 상태에서 70~80초 정도가 주시실험의 적정시간으로 설정하는 것이 가능하다.

Flame Retardancy of Wood Products by Spreading Concentration and Impregnation Time of Flame Retardant(방염제의 도포량과 침지시간 차이에 따른 목재제품의 방염성능)

( Sohyun Park ),( Yeonjung Han ),( Dong Won Son ) 한국목재공학회 2020 목재공학 Vol.48 No.4

The flame retardancy, such as carbonized length and area, of four plank type wood products by the spreading concentration and impregnation time of flame retardant were measured according to standard of the Nation Fire Agency in Republic of Korea. To measure the flame retardancy, Korean pine plywood, Japanese larch plywood, Japanese cypress planks, and perforated birch plywood boards were treated with self-development flame retardant by 300 and 500 g/m2 spreading concentration and those were compared with control specimen. In general, the flame retardant performance of wood products improved as the spreading concentration of flame retardant increased. Except for Japanese larch plywood, there was no significant difference in the flame retardant performance by the spreading concentration. The flame retardant performance of perforated birch plywood board was positively correlated up to 60 minutes of impregnation time, but then gradually decreased. These results about the flame retardancy of wood products by spreading concentration and impregnation time were expected to be basic data for improving flame-retardant treated wood.