PZT센서를 이용한 보의 손상측정

서혜원,김민구,신경재 대한건축학회지회연합회 2008 대한건축학회지회연합회 학술발표대회논문집 Vol.2008 No.1

Various smart sensors have been used for the monitoring of damage predication of structures. In this study, piezoelectric (PZT) sensors were used for the damage prediction of steel member. An impact load was applied on a simply supported steel girder on which PATs were attached, and the dynamic responcd were measured. The voltage change of piezoelectric for the steel girder is used for damage prediction. Damage measuring of steel girder will use the change of voltage of the PZT sensor and it will be able to predict a damage. The measured natural frequency were compared with those of both theorerical analysis as well as those of numerical analysis results using finite element analysis program Midas The damage of steel girder was manipulated by the bolt loosening of ioint with bolt slice. The voltages from PZT sensor were converted to FFT data and the frequency change and magnitude were inspected to identify the damage. The basic data to identify the damage of steel girder were suggested based on the frequency change and magnitude ratio for the different modes.

GaN Nanorod Arrays as a High-Stability Field Emitter

서혜원,L. W. Tu,M. Chen,Q. Y. Ch,A. Bensaoula,X. M. Wang,W. K. CHU 한국물리학회 2017 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.71 No.6

Patterned arrays of epitaxial GaN (0001) nanorods by Si-ion bombardment of Si (111) substrates have been fabricated for the field emitters. The field emission characteristics of the GaN nanorod arrays were measured; both GaN nanorods on self-implanted and GaN matrix on unimplanted Si substrates. The current densities as high as 10 mA/cm2 have been observed for GaN nanorod arrays under applied electrical field of about 70 V/μm, while the stability of field emission at 3.93 mA/cm2 has been tested up to 7 hours with the standard deviation of 0.2%.

PFT와 COPD6의 유용성

서혜원 대한내과학회 2023 대한내과학회 춘계학술대회 Vol.2023 No.0

Community-acquired pneumonia with negative chest radiography findings : Clinical and radiological features

서혜원,차승익,유승수,이신엽,이재희,김창호,박재용 대한결핵 및 호흡기학회 2018 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.126 No.-

Background: Data regarding community-acquired pneumonia (CAP) identified on chest computed tomography (CT) but not on chest radiography (CR) are limited. Objectives: The present study aimed to investigate the clinical and radiological features of these patients. Methods: We retrospectively compared the clinical characteristics, etiological agents, treatment outcomes, and CT findings between CAP patients with negative CR and positive CT findings (negative CR group) and those with positive CR as well as CT findings (control group). Results: Of 1925 patients, 94 patients (4.9%) were classified into the negative CR group. Negative CR findings could be attributed to the location of the lesions and CT pattern with a low attenuation, such as ground-glass opacity (GGO). The negative CR group was characterized by a higher frequency of aspiration pneumonia, lower incidences of complicated parapneumonic effusion or empyema and pleural drainage, and lower blood levels of inflammatory markers than the control group. On CT, the negative CR group exhibited higher rates of GGO- and bronchiolitis-predominant patterns and a lower rate of consolidation pattern. Despite shorter length of hospital stay in the negative CR group, 30-day and in-hospital mortalities were similar between the two groups. Conclusions: CAP patients with negative CR findings are characterized by lower blood levels of inflammatory markers, a higher incidence of aspiration pneumonia, and a lower incidence of complicated parapneumonic effusion or empyema than those with positive CR.

An eQTL variant for LKB1 gene and the clinical outcomes of chemotherapy in non-small cell lung cancer

서혜원,( Deuk Kju Jung ),( Hyo-gyoung Kang ),( Shin Yup Lee ),( Jin Eun Choi ),( Mi Jeong Hong ),( Sook Kyung Do ),( Jang Hyuck Lee ),( Seung Soo Yoo ),( Jaehee Lee ),( Seung Ick Cha ),( Chang Ho Kim ),( 대한결핵 및 호흡기학회 2018 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.126 No.0

Background: We conducted this study to identify regulatory variants in cancer-related pathway genes which can predict clinical outcomes of chemotherapy in advanced NSCLC, using a comprehensive list of regulatory SNPs prioritized by RegulomeDB. Methods: A total of 509 potentially functional SNPs in cancer-related pathway genes were evaluated. The SNPs were analyzed in a discovery set (n=198), and an independent validation set (n=181). The associations of the SNPs with chemotherapy response and overall survival (OS) were analyzed. Results: In the discovery set, 95 SNPs were significantly associated with clinical outcomes. Among the 95 SNPs, only rs10414193A>G in the intronic region of ARID3A, an eQTL for LKB1, was consistently associated with chemotherapy response and OS in the validation set. In combined analysis, the rs10414193A>G was significantly associated with worse response to chemotherapy (adjusted odds ratio=0.63, 95% CI=0.47-0.85, P=0.002), and with worse OS (adjusted hazard ratio=1.25, 95% CI=1.08-1.45, P=0.004). Luciferase assay showed a significantly higher LKB1 promoter activity associated with rs10414193G allele compared with rs10414193A allele (P=0.0009). Conclusions: Our results suggest that rs10414193A>G may be useful for the prediction of clinical outcomes of chemotherapy in advanced NSCLC.

The socioeconomic impact of Korean dental health insurance policy on the elderly: a nationwide cohort study in South Korea

서혜원,이보아,임현선,윤준호,김영택 대한치주과학회 2019 Journal of Periodontal & Implant Science Vol.49 No.4

Purpose: The purpose of this retrospective study was to investigate the relationships of types of dental insurance coverage in Korea with sociodemographic characteristics and the prevalence of systemic and oral diseases, as well as to evaluate the socioeconomic impact of Korean dental insurance policies. Methods: Sample cohort data from 2006 to 2015 were obtained from the National Health Insurance Service. Patients were divided into 2 groups. The exposed group comprised patients who received insurance benefits for complete dentures, removable partial dentures, and implant care, while the control group comprised patients who did not receive these benefits. The type of insurance coverage and the prevalence of systemic and oral diseases were compared between the 2 groups. Results: Patients who received benefits in the form of complete dentures, removable partial dentures, and implants had similar sociodemographic characteristics in terms of sex, age, income quintile, and type of insurance coverage to the control group. The prevalence of hypertension, anemia, renal disease, rheumatoid arthritis, osteoporosis, asthma, and cerebral infarction was higher in the exposed group than in the control group (P<0.05). The prevalence of periodontal diseases and dental caries was also higher in the exposed group. Conclusions: Korean dental health insurance policy has been beneficial for the medical expenses of low-income and elderly people suffering from a cost burden due to systemic diseases. However, since there is a tendency to avoid invasive interventions in older patients due to the high risk of systemic diseases, insurance coverage of dentures may be more helpful from a socioeconomic perspective than coverage of dental implant treatments.

Hydrogen Production by Photoelectrochemical Water Splitting

서혜원,김진수 한국진공학회 2018 Applied Science and Convergence Technology Vol.27 No.4

The basic principle and concept for hydrogen production via water splitting process was introduced. In particular, the recent research activities and their progress in the photoelectrochemical water splitting process were investigated. The material perspectives of semiconducting photocatalyst were considered from metal oxides, including titanium oxides, to carbon compounds and perovskites. The various structural configurations from conventional photoanodes with metal cathodes to tandem and nanostructures were also studied. The pros and cons of each was described in terms of light absorption, charge separation / photoexcited electron-hole pair recombinations and further solar-to-hydrogen efficiency. This article aims to provide the broad view of the up-to-date research and development as well as, possibly, a future direction in the photoelectrochemical water splitting field.

못생긴 강아지

서혜원 세계평화교수협의회 1985 廣場 Vol.143 No.-

Enhanced InN Solid Solubility in Pseudo-Binary InN-GaN (InGaN) Nanostructures

서혜원 한국물리학회 2016 새물리 Vol.66 No.11

We have studied the change in the Gibbs free energy during the formation of a pseudo-binary compound with InN-GaN nanostructures. The addition of a free energy term regarding the surface energy and the radius of curvature in the nanostructure leads to a modulation of the phase diagram for the corresponding bulk. We considered the actual parameters extracted from the InGaN system and found that the binodal and spinodal curves became closer with decreasing radius of the nanostructure; 1) the solid solubility of InN in GaN was promoted, which enhancement became more prominent at a higher growth temperature, and 2) the metastable region formed between the binodal and the spinodal curves became narrower, but the inhomogeneous region under the spinodal decomposition curves became slightly broader. We also found a critical minimum radius, which is inversely proportional to the growth temperature, for the InGaN nanostructures under equilibrium growth conditions.

기능성 첨가제 도입에 따른 고함량 Ni 양극 전지에서의 고전압 구동 성능 향상

서혜원,최회주,이효윤,조국영 한국공업화학회 2021 한국공업화학회 연구논문 초록집 Vol.2021 No.0