• 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.

• Speech Sciences
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• v.7 no.2
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• pp.193-208
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• 2000

This paper describes a multi-step method of intonation modeling for corpus-based Korean speech synthesizer. We selected 1833 sentences considering various syntactic structures and built a corresponding speech corpus uttered by a female announcer. We detected the pitch using laryngograph signals and manually marked the prosodic boundaries on recorded speech, and carried out the tagging of part-of-speech and syntactic analysis on the text. The detected pitch was separated into 3 frequency bands of low, mid, high frequency components which correspond to the baseline, the word tone, and the syllable tone. We predicted them using the CART method and the Viterbi search algorithm with a word-tone-dictionary. In the collected spoken sentences, 1500 sentences were trained and 333 sentences were tested. In the layer of word tone modeling, we compared two methods. One is to predict the word tone corresponding to the mid-frequency components directly and the other is to predict it by multiplying the ratio of the word tone to the baseline by the baseline. The former method resulted in a mean error of 12.37 Hz and the latter in one of 12.41 Hz, similar to each other. In the layer of syllable tone modeling, it resulted in a mean error rate less than 8.3% comparing with the mean pitch, 193.56 Hz of the announcer, so its performance was relatively good.

• Journal of IKEEE
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• v.22 no.2
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• pp.324-329
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• 2018

As the environment of power systems changes, the demand and necessity for new electrical energy market are increasing. Especially, efforts to increase the efficiency of electric energy use by using demand response programs are being studied constantly in advanced countries and it is operated as a real market. This paper presents a study on the baseline load estimation required in the new power market, such as demand response, P2P electricity trading etc. The proposed method estimates the baeline load through analysis of the load pattern and verifies the effectiveness of the proposed method using actual data.

• 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.

• Environmental Analysis Health and Toxicology
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• v.19 no.1
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• pp.49-58
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• 2004

It is important to select a risk based priority area for environmental policy formation and decision-making. We estimated the health risks and associated damage costs from exposure to fine particles and assigned priority areas for twenty -five districts in Seoul. In order to estimate the theoretical mortality incidence of the health risk, baseline risks were estimated from mortality rates in two low level areas of fine particles, Seocho Gu and Cheju city To estimate the damage cost from the risk estimates, we investigated and estimated the willingness to pay (WTP) for specific risk reduction. We assumed two different locations as the reference area, Cheju city as Scenario I and Seocho gu as Scenario II. From the results, the five districts, Kwangjin, Chungnang, Kangbuk, Nowon, and Kangnam, ranked high in the categories of both health risk and economic risk. Damage costs were over twenty billion won in each of these districts. As there are uncertainties in these results, the parameter values such as PM$_{2.5}$ level, dose -response slope factor, baseline risk, exposure population and WTP should be continuously validated and refined.d.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.185-190
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• 2006

The correct estimation of the ionospheric delays is very important for the precise kinematic positioning especially in case of the long baseline. In case of triple frequency system, the ionospheric delays can be estimated from the measurements, but, in case of dual frequency system, the situation is not so simple. The precision of those supplied by the external information source such as IONEX is not sufficient. The high frequency component is neglected, and the precision of the low frequency component is not sufficient for the long baseline positioning. On the other hand, the high frequency component can be estimated from the phase range measurements. If the low frequency components are estimated by using the external information source or pseudo range measurements, a more reasonable estimation of the ionospheric delays may be possible. It has already been discussed by the author that the estimation of the low frequency components by using the external information source is not sufficient but fairly effective. The estimation using the pseudo range measurements is discussed in the present paper. The accuracy is not sufficient at present because of the errors in the pseudo range measurements. It is clarified that the bias errors in the pseudo range measurements are responsible for the poor accuracy of the ionospheric delays. However, if the accuracy of the pseudo range measurements is improved in future, the method would become very promising.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.2
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• pp.135-143
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• 2022

In this paper, the compact waveguide slot array antenna for interferometric radar altimeter is proposed. The proposed antenna structure consist of corrugation structure which is applied between each channel to improve isolation, three-channel waveguide slot array antenna and feeder. In addition, to reduce the occurrence of phase ambiguity, the baseline spacing of the three-channel antenna is analyzed and the results are applied to the design. For compact design, reduced height and SMP connector structure are used and the dip brazing method which is the conjugation method after dipping to flux is used for the fabrication of the lightweight antenna. The measurement result of the proposed antenna shows less than 1.41 : 1 (VSWR) and 48.3 dBc (isolation). The antenna gain is higher than 20.2 dBi and the side lobe levels are lower than 18.8 dB (vertical plane) and 10.0 dB (horizontal plane).

• Korean Journal of Psychosomatic Medicine
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• v.31 no.1
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• pp.19-24
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• 2023

Objectives : Biofeedback is a useful non-pharmacological treatment for panic disorder (PD), but no studies have identified physiological markers related to the treatment response. This study investigated predictors of the treatment response for biofeedback in patients with PD. Methods : A retrospective study based on the electronic medical records of 372 adult patients with PD was performed. Patients received biofeedback treatment at least once, and physiological markers including heart rate, heart rate variability, respiratory rate, skin conductance, skin temperature, and electromyography were collected before the treatment began. The patients were classified as responders or non-responders based on the change in Clinical Global Impression-Severity (CGI-S) score. Results : The response rate to biofeedback treatment was 30.4%. Multivariable logistic regression analysis revealed that a higher CGI-S score at baseline and fewer benzodiazepine prescriptions were associated with a better response to biofeedback treatment. According to subgroup analyses, the baseline CGI-S score, dose of benzodiazepines, and skin conductance are candidate predictors of the response to biofeedback treatment in men, while only baseline disease severity was associated with the treatment response in women. Conclusions : The present results suggest that skin conductance may be target marker and predictor for biofeedback in male patients with PD.

• Journal of the Korean Magnetic Resonance Society
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• v.22 no.3
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• pp.46-53
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• 2018

NMR-based metabolomics needs various knowledge to elucidate metabolic perturbation such as NMR experiments, NMR spectrum processing, raw data processing, metabolite identification, statistical analysis, and metabolic pathway analysis regarding technical aspects. Among them, some concepts of raw data processing and multivariate analysis are not easy to understand but are important to correctly interpret metabolic profile. This article introduces NMR spectrum processing, raw data processing, and multivariate analysis.

• Journal of Korean Academy of Nursing
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• v.41 no.6
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• pp.780-787
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• 2011

Purpose: This study was conducted to examine activities of daily living (ADL) of older adults admitted to Korean long-term care hospitals (LTCHs), and to explore the patient and organizational factors that have an impact on the ADL of this population. Methods: A secondary analysis of the Korean minimum data set (K-MDS) of patients (N=14,369) and of the profiles of LTCHs (N=358) from the Health Insurance Review and Assessment Service was done between January and July 2008. The outcome variable was ADL score 6 months after baseline assessment. Multi-level linear regression was employed to explore the patient and organizational factors that affected ADL scores. Results: Of the patients, 45.4% had a baseline ADL score of between 31 and 40, with a score of 40 indicating that the patient was entirely dependent for all items. None of the organizational characteristics were significantly associated with effects on the ADLs of older adults who had been in a LTHC for at least 6 months. However, patient characteristics, such as age, baseline ADL, frequency of physical therapy, urinary incontinence, fecal incontinence, pressure ulcers, and having a tube or catheter, were significantly associated with ADL 6 months after baseline. Conclusion: In order to maintain and improve the ADL of older adults in LTCHs, we should develop strategies to prevent urinary and fecal incontinence, pressure ulcers, unnecessary tubes or catheters, providing adequate physical therapy. Additional studies should include more detailed information regarding nursing staff, including RN hours for direct care, education level and turnover.