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Wing Design Optimization of a Solar-HALE Aircraft

  • Lim, JaeHoon;Choi, Sun;Shin, SangJoon;Lee, Dong-Ho
    • International Journal of Aeronautical and Space Sciences
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    • v.15 no.3
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    • pp.219-231
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    • 2014
  • We develop a preliminary design optimization procedure in this paper regarding the wing planform in a solar-powered high-altitude long-endurance unmanned aerial vehicle. A high-aspect-ratio wing has been widely adopted in this type of a vehicle, due to both the high lift-to-drag ratio and lightweight design. In the preliminary design, its characteristics need to be addressed correctly, and analyzed in an appropriate manner. In this paper, we use the three-dimensional Euler equation to analyze the wing aerodynamics. We also use an advanced structural modeling approach based on a geometrically exact one-dimensional beam analysis. Regarding the structural integrity of the wing, we determine detailed configuration parameters, specifically the taper ratio and the span length. Next, we conduct a multi-objective optimization scheme based on the response surface method, using the present baseline configuration. We consider the structural integrity as one of the constraints. We reduce the wing weight by approximately 25.3 % from that in the baseline configuration, and also decrease the power required approximately 3.4 %. We confirm that the optimized wing has sufficient flutter margin and improved static longitudinal/directional stability characteristics, as compared to those of the baseline configuration.

Factors to Predict a Remission after Short-Term Pharmacotherapy in Korean Panic Disorder Patients (한국인 공황장애 환자에서 단기간 약물치료 후 관해 예측인자 연구)

  • Sim, Hyun-Bo;Kang, Eun-Ho;Yu, Bum-Hee
    • Anxiety and mood
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    • v.3 no.2
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    • pp.110-115
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    • 2007
  • Objective : The authors examined the treatment response and remission rates in patients with panic disorder after short-term pharmacotherapy in an effort to determine the factors that can be used to predict remission in Korean patients with panic disorder. Methods : Sixty-one patients with panic disorder were recruited for participation in this study. The psychological symptoms of the patients were measured using the HAMA, HAMD, STAIS, STAIT, ASI and API at baseline and after 3 months of pharmacotherapy. Results : Patients with panic disorder showed significantly lower scores on all psychological measures after 3 months of pharmacotherapy with paroxetine. The remission rate was 44.3%, and the response rate was 54.1%. The remitters showed significantly lower HAMD, HAMA, STAIS, STAIT, and ASI scores than the non-remitters. Linear regression analysis revealed that the baseline HAMA, HAMD, and ASI scores could be used to predict the remission rate after controlling for age, sex and agoraphobia. Conclusion : Compared with previous reports, our study showed a similar remission rate in Korean patients with panic disorder. Lower baseline levels of anxiety, depression, and anxiety sensitivity were found to be predictors of treatment remission in panic disorder.

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Climate Change Impacts on Paddy Irrigation Requirement in the Nakdong River Basin (기후변화가 낙동강 권역의 논 관개용수 수요량에 미치는 영향)

  • Chung, Sang-Ok
    • Journal of The Korean Society of Agricultural Engineers
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    • v.51 no.2
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    • pp.35-41
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    • 2009
  • The impacts of climate change on paddy irrigation requirements for Nakdong river basin in Korea have been analyzed. The HadCM3 model outputs for SRES A2 and B2 scenarios and International Water Management Institute $10'{\times}10'$ pixels observed data were used with kriging method. Maps showing the predicted spatial variations of changes in climate parameters and paddy irrigation requirements have been produced using the GIS. The results showed that the average growing season temperature was projected to increase by $2.2^{\circ}C$ (2050s A2), $0.0^{\circ}C$ (2050s B2), $3.7^{\circ}C$ (2080s A2) and $2.9^{\circ}C$ (2080s B2) from the baseline (1961-1990) value of $21{\circ}C$. The average growing season rainfall was projected to increase by 15.2% (2050s A2), 24.2% (2050s B2), 41.4% (2080s A2) and 16.7% (2080s B2) from the baseline value of 900 mm. Average volumetric irrigation demands were projected to decrease by 3.7% (2050s A2), 7.0% (2050s B2), 10.2% (2080s A2) and 1.4% (2080s B2) from the baseline value of $1.25{\times}10^9\;m^3$. These results can be used for the agricultural water resources development planning in the Nakdong river basin for the future.

The Direction Finding Ambiguity Analysis for 3 Element and 4 Element Phase Interferometer DF System (3소자 및 4소자 위상인터페로미터 방탐시스템의 방탐모호성분석)

  • Lee, Jung-Hoon;Woo, Jong-Myung
    • Journal of the Korea Institute of Military Science and Technology
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    • v.17 no.4
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    • pp.544-550
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    • 2014
  • In this paper, we have proposed a novel method which can analysis the direction finding ambiguity analysis for array geometry in 3 channel and 4 channel multiple baseline direction finding system. Generally, the direction finding ambiguity in the 3 element and 4 element phase interferometer direction finding system is calculated by the simulation for the array spacing or by the probability with the selected antenna array spacing. There are some restrictions to obtain the ambiguity of direction finding system in these methods. The former performs a simulation with every antenna array spacing and the latter calculates the ambiguity with the selected antenna array spacing. To overcome those restrictions, This paper proposed the novel method to calculate the ambiguity using the imaginary antenna array spacing and the phase difference prior to the modular operation in direction finder. Using the proposed method, we obtain the ambiguity probability for each of array geometry composed of multiple baseline. After performing the simulation with the selected antenna array spacing to verify the proposed method, we compared the calculated result data with the simulation data.

A Baseline Correction for Effective Analysis of Alzheimer’s Disease based on Raman Spectra from Platelet (혈소판 라만 스펙트럼의 효율적인 분석을 위한 기준선 보정 방법)

  • Park, Aa-Ron;Baek, Sung-June
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.49 no.1
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    • pp.16-22
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    • 2012
  • In this paper, we proposed a method of baseline correction for analysis of Raman spectra of platelets from Alzheimer's disease (AD) transgenic mice. Measured Raman spectra include the meaningful information and unnecessary noise which is composed of baseline and additive noise. The Raman spectrum is divided into the local region including several peaks and the spectrum of the region is modeled by curve fitting using Gaussian model. The additive noise is clearly removed from the process of replacing the original spectrum with the fitted model. The baseline correction after interpolating the local minima of the fitted model with linear, piecewise cubic Hermite and cubic spline algorithm. The baseline corrected models extract the feature with principal component analysis (PCA). The classification result of support vector machine (SVM) and maximum $a$ posteriori probability (MAP) using linear interpolation method showed the good performance about overall number of principal components, especially SVM gave the best performance which is about 97.3% true classification average rate in case of piecewise cubic Hermite algorithm and 5 principal components. In addition, it confirmed that the proposed baseline correction method compared with the previous research result could be effectively applied in the analysis of the Raman spectra of platelet.

The Effect of Interactive Metronome Training on Attention to Autism Spectrum Disorder Children: Single Case Study (상호작용식 메트로놈(Interactive Metronome; IM) 훈련이 자폐 스펙트럼 장애아동의 주의집중력에 미치는 영향 : 단일대상연구)

  • Cho, Sun Young;Ju, Yumi
    • Therapeutic Science for Rehabilitation
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    • v.7 no.4
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    • pp.57-66
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    • 2018
  • Objective: The purpose of this study is to investigate the effect of interactive metronome (IM) training on attention among children on the autistic spectrum. Methods: This is a single case study, using ABA design, of one child with autism spectrum disorder (ASD) who had attentional difficulties. A total of 20 sessions were conducted: 3 baseline sessions (A), 14 intervention sessions (B), and 3 follow-up baseline sessions (A'). During the intervention period (B), IM training was performed. Inattention and attention activities were measured as the dependent variables in all three phases (A, B, and A'). Results: Compared to baseline, the subject's inattention decreased in the IM training mediation period, and the performance of activities requiring attention also improved. The intervention effect was maintained even during the follow-up baseline period. Conclusion: The results of this study suggest that IM training positively influences attention among children with ASD with attention deficit symptoms. Further, it provides the clinical basis of IM training as an intervention for children with ASD.

(A Design of Adaptive Neural Network Filter to Remove the Baseline Wander of ECG) (심전도 신호의 기저선 잡음 제거를 위한 적응 신경망 필터 설계)

  • Lee, Geon-Gi;Kim, Yeong-Il;Lee, Ju-Won;Jo, Won-Rae
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.39 no.1
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    • pp.76-84
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    • 2002
  • In this paper, it is studied to remove the baseline wander and to minimize the distortion of ST segment in the noise filtering of ECG. In general, the standard filter and adaptive filter are used to remove the baseline wander of the ECG. But the standard filter is limited because the frequency of the baseline signal is variable and the apative filter is difficult to select the reference signal in case of using the adaptive filter. So we proposed a new method of the structure without reference signal using neural networks. To be convinced of the performance of this method, we used ECG data of MIT-BIHs. and obtained the result of the high performance,(-53.3[dB]) than standard filter(-16.3[dB]) and adaptive filter (-44.9[dB]).

Prediction of Paddy Irrigation Demand in Nakdong River Basin Using Regional Climate Model Outputs (지역기후모형 자료를 이용한 낙동강 권역의 논 관개용수 수요량 예측)

  • Chung, Sang-Ok
    • Journal of The Korean Society of Agricultural Engineers
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    • v.51 no.4
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    • pp.7-13
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    • 2009
  • The paddy irrigation demand for Nakdong river basin in Korea due to the climate change have been analyzed using regional climate model outputs. High-resolution (27 ${\times}$ 27 km) climate data for SRES A2 scenario produced by the Meteorological Research Institute (METRI), South Korea, and the observed baseline climatology dataset (1971-2000) were used. The outputs from the ECHO-G GCM model were dynamically downscaled using the MM5 regional model by METRI. Maps showing the predicted spatial variations of changes in climate parameters and paddy irrigation requirements have been produced using the geographic information system. The results of this study showed that the average growing season temperature will increase steadily by 1.5 $^{\circ}C$ (2020s A2), 3.2 $^{\circ}C$ (2050s A2) and 5.2 $^{\circ}C$ (2080s A2) from the baseline (1971-2000) 19.8 $^{\circ}C$. The average growing season rainfall will change by -3.4 % (2020s A2), 0.0 % (2050s A2) and +16.5 % (2080s A2) from the baseline value 886 mm. Assuming paddy area and cropping pattern remain unchanged the average volumetric irrigation demands were predicted to increase by 5.3 % (2020s A2), 8.1 % (2050s A2) and 2.2 % (2080s A2) from the baseline value 1.159 ${\times}$ $10^6\; m^3$. These projections are different from the previous study by Chung (2009) which used a different GCM and downscaling method and projected decreasing irrigation demands. This indicates that one should be careful in interpreting the results of similar studies.

Prediction of the Hepatotoxicity Risk Factor Induced by Antituberculosis Agents in Koreans (한국인의 항결핵제에 의한 간독성 위험인자 예측)

  • Lee, Ji-Sun;Kim, Hyun-Ah;Cho, Eun;Lee, Ok-Sang;Lim, Sung-Cil
    • YAKHAK HOEJI
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    • v.55 no.4
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    • pp.352-360
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    • 2011
  • Standard combination chemotherapy including isoniazid, rifampin, pyrazinamide, and ethambutol is very effective against tuberculosis. But, these medicines can cause hepatotoxicity which is the main reason for treatment interruption or change in drug regimen. In order to identify risk factors associated with hepatotoxcity in Koreans and assess elevated baseline LFTs' contributions to hepatotoxicity, a retrospective case control study was performed. The medical records of 277 patients who diagnosed with tuberculosis at a community hospital from January 1st, 2007 to June 30th, 2010 were reviewed. Patients were categorized into 3 groups (non toxic group, patients without increase in LFT levels; mild to moderate hepatotoxic group and severe hepatotoxic group). And the correlation between risk factors and hepatotoxicity was analyzed by using SPSS program. The overall incidence of hepatotoxicity was 18% and 8.7% of patients developed severe toxicity. Patients in the severe toxic group had the longest treatment period among the three groups. In 75% of severe toxic group, hepatotoxicity occurred within 18.3 days after starting medication. Hypoalbuminemia (serum albumin <3 g/dl) was a significant risk factor for development of severe toxicity. Elevated baseline transaminase (except ALT), total bilirubin, and preexisting hepatitis were also risk factors which were more than twice as likely to increase risk of severe hepatotoxicity (p>0.05). In conclusion, hypoalbuminemia (serum albumin level <3 g/dl) was a significant risk factor for anti-tuberculosis druginduced severe toxicity. Therefore, before starting antituberculosis chemotherapy, serum albumin level should be assessed at baseline. In high-risk patients (hypoalbuminemia, elevated LFTs) for hepatotoxicty, liver function should be closely monitored up to at least 21 days after taking medication.

Prospective Study on the Relating Factors to the Stages of Change in Smoking Cessation and Barriers in Coronary Artery Disease Patients* (관상동맥질환자의 금연변화단계와 관련된 요인 및 장애요인에 대한 전향적 연구)

  • Kim, Hwa-Soon
    • Journal of Korean Academy of Nursing
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    • v.35 no.1
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    • pp.27-36
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    • 2005
  • Purpose: The main purpose of this study was to investigate that the stages of change in smoking cessation behavior among coronary artery disease patients for six months progressed following the stages of change suggested by the transtheoretical model. Method: Subjects for this descriptive survey were 59 coronary disease patients who were smoking or who had stopped smoking for less than six months. Result: In the baseline, the distribution of the subjects’ stages of change was as follows: pre-contemplation stage 25.4%, contemplation stage 25.4%, preparation stage 22%, and action stage 27.1%. After six months, more subjects in the contemplation(33.3%) and preparation stages(30.8%) progressed to the action stage than those of the pre-contemplation stage(0%). Eighty-one percent of the subjects in the action stage at baseline progressed to the maintenance stage. The relationship between the numbers of smoking cessation attempts for six months and stages of change at baseline was significant(p=.001). However, the relationships between self-efficacy and nicotine dependence at baseline and progression in stages of change after six months were not significant. Conclusion: Progression in the stages of change for six months among subjects corresponded to the stages of change suggested by the transtheoretical model. Hence, future development and evaluation of intervention programs should be tailored individually considering each patient's stage of change.