• Korean Journal of Ecology and Environment
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• v.52 no.1
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• pp.13-20
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• 2019

Heavy metals resulted from the increase of human industrial activity are introduced into the environment through rainfall and wastewater, and have harmful effects on inhabitants. In this study, we investigated biological responses such as survival rate, growth rate, emergence rate and sex ratio, and morphological effects of mentum deformity in Chironomus plumosus, an indicator organism to evaluate pollutions on aquatic ecosystem. The survival rate of C. plumosus showed time- and dose-dependent decrease after chromium and copper exposures. Growth rate decreased at $4^{th}$ day after chromium exposure and significantly reduced at exposure to relatively high concentration (copper $1000mg\;L^{-1}$) for all exposure times. In addition, we observed that the emergence rate by exposure to copper $1000mg\;L^{-1}$ was significantly lower than that of the control group. The imbalance of sex ratios showed at relatively low concentrations (chromium 10 and $50mg\;L^{-1}$) with the high proportion of female and at the relative high concentration (copper $1000mg\;L^{-1}$) with the high proportion of male. Furthermore, the morphological mentum deformities of C. plumosus observed in the exposed group according to chromium and copper exposure. These results suggest that the heavy metal exposure in environment may influence biosynthetic and morphological stresses of benthic invertebrate C. plumosus, and aquatic midge C. plumosus are potential indicators for toxicity assessment of heavy metals such as chromium and copper.

• The Korean Journal of Mycology
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• v.19 no.4
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• pp.258-265
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• 1991

Ubiquinone compounds of strains in Leucosporidium scottii, Leucosporidium fellii, Leucosporidium lari-marini, and Rhodosporidium fluviale were analyzed by the high performance liquid chromatography. The Q-9 or Q-l0 compounds, independent on mating or self-sporulating type, were determined in the analyses of Leucosporidium scottii strains. Particularly, there is heterogenous in the quinone compounds in the same strain of L. scottii. These results showed reassessment of the quinone compounds as a taxonomic criterion; L. fellii had the Q-9 compound, L. lari-marini the Q-8 compound, and R. fluviale the Q-10 compound, Taxonomic position of L. lari-marini should be elucidated on the basis of analysis of Q-compound with other aspects.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.05a
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• pp.448-450
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• 2023

본 논문에서는 복부 CT 의료영상에서 근감소증 진단을 위한 지표로 활용하는 요추 3번 슬라이스를 분류하기 위해서 CNN 기반의 EfficientNetV2를 사용하여 자동분류모델을 개발하였다. 이를 위해 먼저 전체 복부 CT 의료영상에서 Thoracic, L1, L2, L3, L4, L5, Sacral 7개의 슬라이스를 검출하도록 하였다. 자동분류모델의 정확성을 측정하기 위해서 Test 데이터셋을 사용하여 Confusion Matrix 결과를 통해 개발된 모델의 성능을 검증한 결과를 보였다. 본 연구결과는 복부 CT 영상에서 기존 L3 레벨의 특정 단면에서 근육량을 측정하는 것에서 다양한 부위에서 측정할 수 있는 장점을 갖게 된다. 그리고 의료영상기반의 근감소증 진단 연구에 도움을 줄 것으로 기대하고 있다.

• Tuberculosis and Respiratory Diseases
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• v.42 no.3
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• pp.332-341
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• 1995

Background: Measurement of bronchodilator response is necessary to establish reversibility of airflow obstruction that was helpful to estimate the diagnosis, treatment, and prognosis in obstructive airway disease. An useful index should be able to detect the bronchodilator response more sensitively not related with degree of airflow obstruction and also be independent of initial $FEV_1$. Method: Sensitivities of bronchodilator response in each group classified by degree of airflow obstruction in $FEV_1$, FVC, $FEF_{25\sim75%}$, Isovolume $FEF_{25\sim75%}$, sGaw were studied and correlation coefficients were calculated between initial $FEV_1$ and reversibilities expressed as absolute, %initial, % predicted, %possible in $FEV_1$. Result: Sensitivities of bronchodilator response were 61.5% in FVC, Isovolume $FEF_{25\sim75%}$ and sGaw, in severe group, and 56.3% in Isovolume $FEF_{25\sim75%}$ and sGaw, in moderate group, and 62.5% in $FEV_1$ and sGaw and 50.0% in FVC and Isovolume $FEF_{25\sim75%}$, in mild group, and 60.0% in sGaw and 58.0% in Isovolume $FEF_{25\sim75%}$ in total patients. Correlation coefficients between initial $FEV_1$(L) and absolute, % initial, % predicted, % possible were 0.15, -0.22(p<0.05), 0.02, 0.24(p<0.05) and correlation coefficients between initial $FEV_1$(% predicted) and absolute, % initial, % predicted, %possible were 0.06, -0.28(p<0.05), 0.08, 0.39(p<0.05). Conclusion: Volume related parameters were more sensitive index not related with degree of airway obstruction and the change in $FEV_1$ expressed as % predicted was the least dependent on initial $FEV_1$ and reversibilities, expressed as % initial or as % possible(predicted minus initial $FEV_1$)were correlated with initial $FEV_1$.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.954-961
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• 2010

Ground-based remote sensing can be used as one of the non-destructive, fast, and real-time diagnostic tools for quantifying yield, biomass, and nitrogen (N) stress during growing season. This study was conducted to assess biomass and nitrogen (N) status of paddy rice (Oryza sativa L.) plants under N stress using passive and active ground-based remote sensors. Nitrogen application rates were 0, 70, 100, and 130 kg N $ha^{-1}$. At each growth stage, reflectance indices measured with active sensor showed higher correlation with DW, N uptake and N concentration than those with the passive sensor. NIR/Red and NIR/Amber indices measured with Crop Circle active sensors generally had a better correlation with dry weight (DW), N uptake and N content than vegetation indices from Crop Circle passive sensor and NDVIs from active sensors. Especially NIR/Red and NIR/amber ratios at the panicle initiation stage were most closely correlated with DW, N content, and N uptake. Rice grain yield, DW, N content and N uptake at harvest were highly positively correlated with canopy reflectance indices measured with active sensors at all sampling dates. N application rate explains about 91~92% of the variability in the SI calculated from NIR/Red or NIR/Amber indices measured with Crop Circle active sensors on 12 July. Therefore, the in-season sufficiency index (SI) by NIR/Red or NIR/Amber index from Crop Circle active sensors can be used for determination of N application rate.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.313-318
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• 2001

In this paper, the well-conditioned observer is designed to be insensitive to the ill-conditioning factors in transient and steady-state observer performance. A condition number based on $L_2-norm$ of the eigenvector matrix of the observer matrix has been proposed on a principal index in the observer performance. For the well-conditioned observer design, the non-normality measure and the observability condition of the observer matrix are utilized. The two constraints are specified into observer gain boundary region that guarantees a small condition number and a stable observer. The observer gain selected in this region guarantees a well-conditioned and observable property. In this study, this method is applied to the Luenberger observer and Kalman filters. In designing Kalman filters for small order systems, the ratio of the process noise covariance to the measurement noise covariance is a design parameter and its effect on the condition number is investigated.

• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.547-552
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• 2015

이번 연구에서는 Ali & Ramadhayni[2]에 의해 실험된 corrugated fin에 Cross-Cutting을 하여 압력강하를 2-D Laminar 영역에서 분석하였다. 분석 지표로는 Pressure drop의 무차원화된 지표인 friction factor를 사용하였고, corrugation angle을 $10^{\circ}$, $20^{\circ}$, $30^{\circ}$로 변화 시켜가며 진행하였다. Cross-Cutting의 길이는 $0.3D_h$길이로 고정시켜 계산하였고, 모든 값은 $D_h=2l$로 무차원화 하였다. Corrugated Fin의 경우, Corrugation Angle에 따라 층류영역에서 주기성을 가진 vortex shedding이 일어나는데, 그 때의 레이놀즈 수를 본 연구에서는 임계 레이놀즈 수라 하고, Vortex Shedding이 일어나기 시작하는 $Re_{cr}$ 이하에서 연구를 진행하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.10
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• pp.2067-2072
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• 2002

The closed-loop state and input observer is a pole-placement type observer and estimates unknown state and input variables simultaneously. Pole-placement type observers may have poor performances with respect to modeling error and sensing bias error. The effects of these ill-conditioning factors must be minimized for the robust performance in designing observers. In this paper, the steady-state performance of the closed-loop state and input observer is investigated quantitatively and is represented as the estimation error bounds. The performance indices are selected from these error bounds and are related to the robustness with respect to modeling errors and sensing bias. By considering both transient and steady-state performance, the main performance index is determined as the condition number of the eigenvector matrix based on $L_2$-norm.

• Proceedings of the Korea Information Processing Society Conference
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• 2024.05a
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• pp.709-710
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• 2024

Super resolution에서 High-frequency Details를 개선하는 것이 최근 문제이다. 기존에는 Super resolution을 Regression task로 접근하므로써 L2 Loss를 사용하여 이미지가 흐릿하게 되었다. 이를 해결하기위해, Classification task로 바꾸므로써 Cross Entropy Loss을 적용하여 Cross-entropy Super-resolution (CS)를 설계한다. CS를 통해 선명도와 Details이 개선되지만, 저주파의 CE Loss 학습으로인한 Black Artifacts가 발생한다. 그래서, L2 Loss는 저주파와 같이 큰 신호에 더 초점을 맞추므로, 성능 개선을 위해 저주파를 L2 Loss에서, 고주파를 CE Loss에서 학습시킨 Frequency-specific Cross-entropy Super-resolution (FCS)을 제안한다. 우리는 왜곡에 강하며 Human의 인식과 유사한 측정지표인 Learned Perceptual Image Patch Similarity (LPIPS)로 평가한다. 실험한 모든 데이터 셋에서 우리의 FCS는 Baseline보다 LPIPS가 약 1.7배 정도 개선되었다.

• Tuberculosis and Respiratory Diseases
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• v.48 no.1
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• pp.14-23
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• 2000

Background: The evaluation of candidates for successful lung resection is important. Our study was conducted to determine the preoperative predictors of postoperative mortality and morbidity in lung cancer patients with impaired lung function. Method; Between October 1, 1995 and August 31, 1997, 36 lung resection candidates for lung cancer with $FEV_1$ of less than 2L or 60% of predicted value were included prospectively. Age, sex, weight loss, hematocrit, serum albumin, EKG and concomitant illness were considered as systemic potential predictors for successful lung resection. Smoking history, presence of pneumonia, dyspnea scale(l to 4), arterial blood gas analysis with room air breathing, routine pulmonary function test were also included for the analysis. In addition, predicted postoperative(ppo) pulmonary factors such as ppo-$FEV_1$ ppo-diffusing capacity(DLco), predicted postoperative product(PPP) of ppo-$FEV_1%{\times}$ppo-DLco% and ppo-maximal $O_2$ uptake($VO_2$max) were also measured. Results: There were 31 men and 5 women with the median age of 65 years(range, 44 to 82) and a mean $FEV_1$ of $1.78{\pm}0.06L$. Pneumonectomy was performed in 14 patients, bilobectomy in 8, lobectomy in 14. Pulmonary complications developed in 10 patients; cardiac complications in 3, other complications(empyema, air leak, bleeding) in 4. Twelve patients were managed in the intensive care unit for more than 48 hours. Two patients died within 30 days after operation. The ppo-$VO_2$max was less than 10 ml/kg/min in these two patients. MVV was the only predictor for the pulmonary complications. However, there was no predictor for the post operative death in this study. Conclusions: Based on the results, MVV was the useful predictor for postoperative pulmonary complications in lung cancer resection candidates with impaired lung function In addition, ppo-$VO_2$max value less than 10 ml/kg/min was associated with postoperative death, so exercise pulmonary function test could be useful as preoperative test. But further studies are needed to validate this result.