• The Korean Journal of Physiology and Pharmacology
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• 제3권2호
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• pp.223-230
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• 1999

Alterations of cardiovascular function associated with various thyroid states have been studied. In hyperthyroidism left ventricular contractility and relaxation velocity were increased, whereas these parameters were decreased in hypothyroidism. The mechanisms for these changes have been suggested to include alterations in the expression and/or activity levels of various proteins; ${\alpha}-myosin$ heavy chain, ${\beta}-myosin$ heavy chain, ${\beta}-receptors,$ the guanine nucleotide-binding regulatory protein, and the sarcolemmal $Ca^{2+}-ATPase.$ All these cellular alterations may be associated with changes in the intracellular $Ca^{2+}$ concentration. The most important regulator of intracellular $Ca^{2+}$ concentration is the sarcoplasmic reticulum (SR), which serves as a $Ca^{2+}$ sink during relaxation and as a $Ca^{2+}$ source during contraction. The $Ca^{2+}-ATPase$ and phospholamban are the most important proteins in the SR membrane for muscle relaxation. The dephosphorylated phospholamban inhibits the SR $Ca^{2+}-ATPase$ through a direct interaction, and phosphorylation of phospholamban relieves the inhibition. In the present study, quantitative changes of $Ca^{2+}-ATPase$ and phospholamban expression and the functional consequences of these changes in various thyroid states were investigated. The effects of thyroid hormones on (1) SR $Ca^{2+}$ uptake, (2) phosphorylation levels of phospholamban, (3) SR $Ca^{2+}-ATPase$ and phospholamban protein levels, (4) phospholamban mRNA levels were examined. Our findings indicate that hyperthyroidism is associated with increases in $Ca^{2+}-ATPase$ and decreases in phospholamban levels whereas opposite changes in these proteins occur in hypothyroidism.

• 센서학회지
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• 제26권5호
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• pp.306-313
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• 2017

An early detection of infiltration in veins is essential to minimize the injuries caused during infusion therapy, which is one of the most important tasks for nurses in clinical settings. We report that bioelectrical impedance analysis is useful in the early detection of infiltration at puncture sites. When infiltration was intentionally induced in the vein of a rabbit's ear, impedance parameters showed significant difference before and after infiltration. In particular, the relative resistance at 20 kHz in the vein of rabbit's ear reduced largely at infiltration, decreased slowly, and then stayed at a constant value. This indicates that the vein in the ear of the rabbit is small, and hence the infiltrated intravenous (IV) solution no longer accumulates after 3 minutes of infiltration. However, when infiltration was induced in the vein of a human's forearm, the relative resistance at 20 kHz decreased gradually over time. In the $R-X_c$ graph, the positions in infiltration induced in the rabbit's ear rapidly shifted before and after infiltration whereas the positions in infiltration induced in the human's forearm changed gradually during infiltration. Our findings suggest that bioelectrical impedance analysis is an effective method to detect the infiltration early in a noninvasive and quantitative manners.

• 감성과학
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• 제17권2호
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• pp.63-76
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• 2014

대부분의 인지적 과제에서 관찰되는 반응시간 자료의 분포는 정적으로 편포되어 나타남에도 불구하고, 반응시간을 종속측정치로 하는 대다수의 연구들은 표본 평균에 근거한 집중경향치 분석에 의존한다. 본 연구에서는 반응시간 자료의 분포특성에 분석의 초점을 맞추어 실험적 처치의 효과를 구체적으로 추론하는 방법을 소개하였다. 평균 반응시간의 변화는 그 분포상 가우시안 및 지수 분포가 혼합된 형태로 나타난다고 가정할 수 있으며, 최대우도 추정법에 근거한 ex-Gaussian 모형 검증을 통해 반응시간 분포 특성을 수치화된 파라미터로 산출하고 확률밀도함수를 구현할 수 있다. 분석 사례를 위해 두 가지 고전적 시각탐색과제에서 얻어진 반응시간 자료를 사용하였으며, ex-Gaussian 함수를 통해 탐색배열의 항목개수의 증가가 초래하는 평균 반응시간의 지연효과에 대한 해석을 시도하였다. 수리적 모형을 통한 반응시간 분포 분석은 고전적 집중경향치 분석의 한계를 넘어 반응시간을 활용한 다양한 이론 및 개인차 연구에서 활용될 수 있을 것으로 기대된다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.183-184
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• 2006

Some researchers proposed positive effects of whole body vibration (WBV) on osteoporotic trabecular bones of animals. In the present study, the correlation between the improvement of morphological characteristics and the effect of WBV was investigated and analyzed in OVX rats. The rats were randomly assigned to 5 groups: control, sham, WBV 17Hz, WBV 30Hz and WBV 45Hz. The WBV groups were exercised on a vibration platform (magnitude : $1mm_{peak-peak}$, frequency : 17Hz, 30Hz and 45Hz, 30 minutes/day for 5 days/week). The 4th lumbar on rats was scanned by In-vivo Micro-CT at the week 0(just before WBV) and the week 8(after WBV). Structural parameters of the 4th lumbar, based on two dimensional (2D) scan image data, were investigated and analyzed. The quantitative decrement rate of trabecular bone on WBV groups with 30Hz and 45Hz were lower than control and sham groups. The results showed the positive effect of WBV on osteoporotic bones of OVX rats.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.649-650
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• 2006

Some researchers proposed positive effects of whole body vibration (WBV) on osteoporotic trabecular bones of animals. In the present study, the correlation between the improvement of morphological characteristics and the effect of WBV was investigated and analyzed in OVX rats. The rats were randomly assigned to 5 groups: control, sham, WBV 17Hz, WBV 30Hz and WBV 45Hz. The WBV groups were exercised on a vibration platform (magnitude $1mm_{peak-peak}$, frequency : 17Hz, 30Hz and 45Hz, 30 minutes/day for 5 days/week). The 4th lumbar on rats was scanned by In-vivo Micro-CT at the week 0(iust before WBV) and the week 8(after WBV). Structural parameters of the 4th lumbar, based on two dimensional (2D) scan image data, were investigated and analyzed. The quantitative decrement rate of trabecular bone on WBV groups with 30Hz and 45Hz were lower than control and sham groups. The results showed the positive effect of WBV on osteoporotic bones of OVX rats.

• 생약학회지
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• 제17권3호
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• pp.248-254
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• 1986

Effects of vinblastine(VLB) and vincristine(VCR) on cell-mediated immunity(CMI) were studied with the microcytotoxicity test(MCT) after normal or pre-sensitized Balb/c mice had been treated in vivo with a combination of two different doses of VLB or VCR(single dose of 20% and 60% $LD_{50}$, i.p.) at different times (from day -6 to day +4) plus allo-transplantation antigen(allo-TA, cells from C3H mice at day 0). The results were that $LD_{50}$ of VLB for female Balb/c mouse was 7.3mg/kg body weight (i.p.) and $LD_{50}$ of VCR was 4.3mg/kg body weight and that VLB and VCR acted as immunosuppressive agents on the primary CMI when administered after allo-TA(antigen-drug-phase), but showed no effect when administered prior to allo-TA(drug-antigen-phase). Change of doses of VLB and VCR(20% $LD_{50}$, 60% $LD_{50}$) caused quantitative or qualitative variations in the immunomodulating effects of these two drugs. Neither VLB nor VCR had any immunomodulating effect on the secondary CMI. Lastly, the results support that the four parameters (type of drug, sensitization status, time of drug treatment in relation to antigen injection, and drug dosis) are significant for the effects of the VLB and VCR on the CMI, and that VLB and VCR may inhibit the proliferation of antigen-stimulated T effector lymphocytes but not memory-cytotoxic T lymphocytes.

• 한국물환경학회지
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• 제33권3호
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• pp.326-333
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• 2017

The lakes and reservoirs have been reported as important sources of carbon emissions to the atmosphere in many countries. Although field experiments and theoretical investigations based on the fundamental gas exchange theory have proposed the quantitative amounts of Net Atmospheric Flux (NAF) in various climate regions, there are still large uncertainties at the global scale estimation. Mechanistic models can be used for understanding and estimating the temporal and spatial variations of the NAFs considering complicated hydrodynamic and biogeochemical processes in a reservoir, but these models require extensive and expensive datasets and model parameters. On the other hand, data driven machine learning (ML) algorithms are likely to be alternative tools to estimate the NAFs in responding to independent environmental variables. The objective of this study was to develop random forest (RF) and multi-layer artificial neural network (ANN) models for the estimation of the daily $CO_2$ NAFs in Daecheong Reservoir located in Geum River of Korea, and compare the models performance against the multiple linear regression (MLR) model that proposed in the previous study (Chung et al., 2016). As a result, the RF and ANN models showed much enhanced performance in the estimation of the high NAF values, while MLR model significantly under estimated them. Across validation with 10-fold random samplings was applied to evaluate the performance of three models, and indicated that the ANN model is best, and followed by RF and MLR models.

• 비파괴검사학회지
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• 제26권2호
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• pp.122-129
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• 2006

본 논문에서는 레이저 응용 비파괴검사 기술인 Shearography를 이용하여 압력 배관 내부 결함의 검출에 있어서 미치는 전단량의 영향을 분석하였다. Shearography는 레이저 응용기법에 비하여 환경 외란에 둔감하며, 대상체 표면의 상대 변위를 검출함으로서 비파괴검사 분야에서 많은 활용이 기대된다. 현재까지 연구는 적용 가능성의 평가와 적용 대상의 확대에 중점을 두어 연구가 진행되어 왔으며, 결함의 정량평가를 위해서는 결함 검출에 있어서 영향을 주는 인자들에 대한 연구가 필요하다. 따라서 본 논문에서는 결함의 검출에 영향을 줄 수 있는 전단량의 변화에 따라 결함의 크기 측정과 길함의 위치 결정에 대한 영향을 예측하고, 압력용기 내부의 길이 방향 인공 결함에 대해 적용하여 검출 결과를 분석하였다.

• 한국측량학회지
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• 제27권4호
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• pp.429-435
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• 2009

본 연구에서는 항공 디지털 프레임 카메라에 의해 제작된 모자이크 영상의 정량적인 품질 평가를 위해 HSI 색상 모델을 이용한 색상평가 방법을 제안하였다. 이를 위하여 먼저 RGB칼라 영상을 HSI색상모델로 변환 후, 모자이크영상의 접합영상에 대해 6가지 동일한 색상에 해당하는 채도와 명도의 화소정보를 추출한다. 이 후, 접합영상을 객관적으로 평가하기 위하여 유사성과 대비 측정을 위해 4가지 평가인자를 산출하였으며, 이에 대한 정량적인 평가를 수행하였다. 그 결과 제안된 영상 평가 방법이 육안 평가 방법과 거의 유사한 결과를 보여주고 있음을 확인하였다. 따라서 본 연구에서는 모자이크영상에 대해 시각적으로 판단하기 어려운 문제점을 정량적으로 나타냄으로써 영상 자체의 품질을 평가하기 위한 객관화된 방안을 제시하였다.

• 한국식품영양학회지
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• 제26권3호
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• pp.414-420
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• 2013

The aim of this study was to investigate the effects of environmental factors such as temperature, salinity, turbidity and pH on the growth of pathogenic Vibrios. In this study, we was obtained the samples from 2 different sites of the Incheon coastal area between January 2012 and December 2012. The water temperature in August and September was the high. the Incheon port changes the width of a small, wherease in the case of Hanjin harbor of changes of larger width. Salinity and turbidity showed significant differences, whereas temperature and hydrogen ion concentration was not significant. Pathogenic vibrios was determined using the real-time PCR method. Pathogenic vibrios in the Incheon port and Hanjin harbor were detected in 11 samples (91.67%) and 9 samples (75.0%) of Vibrio cholerae, 7 samples (58.3%) and 6 samples (50.0%) of V. vulnificus, 10 samples (83.3%) and 12 samples (100.0%) of V. parahaemolyticus, respectively. Pathogenic Vibrio bacteria were the highest at $26.8^{\circ}C$ of seawater in August. Quantitative results were the following: 102 $cell/m{\ell}$ in Vibrio cholerae, 7.876 $cell/m{\ell}$ in V. vulnificus, and 503.4 $cell/m{\ell}$ in V. parahaemolyticus, respectively. The enumeration of pathogenic vibrios showed a positive correlation with temperature and pH, but was negatively correlated with salinity and turbidity.