http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
정현용,이대경,John Losey 한국HCI학회 2022 한국HCI학회 학술대회 Vol.2022 No.2
It is difficult to evaluate the reduction rate of a species that has a high number of habitats and populations. In addition to the amount of insufficient data present to cover the entire habitat, the inconsistency of study areas and investigation efforts between monitoring programs is a major obstacle to quantifying long-term population decline. To overcome the bias from (1) data insufficiency and (2) inconsistency derived from compiling various investigative sources, including citizen science projects, this study proposes a procedure to estimate the reduction rate using machine learning. After predicting the possibility of occupancy every year through a fitted model in all habitats where target species have been recorded, a trend line is formulated and used for approximating reduction. By the newly described oversampling approach, including indirect occupancy data points, we were able to secure about three times the amount of information on the direct occupancy data points. Compared to the model that learned only the direct occupancy data set, the performance matrix of the model utilizing the new oversampling approach was about 10% higher overall. As a result, the estimated reduction rate of Coccinella novemnotata was 31.2% over the past decade, which corresponds to the VU status in the IUCN Red List. In addition, the machine learning method showed a lower degree of fluctuation in approximations (within 13%) than the relative abundance method (within 42%) and the segmented linear extrapolation method (within 55%), when we integrated 10% of fake information into the data set.
정현용 大田大學校 社會科學硏究所 2016 社會科學論文集 Vol.38 No.2
본 연구는 한국정보화진흥원에서 매년 발간(2011년~2018년)한 스마트폰 과의존 실태조사 보고서를 분석하여 스마트폰 과의존 현상이 어떻게 변화되는지 실태를 분석하고 그 대안을 제시하는 데 그 목적이 있다. 스마트폰 과의존이란 과도한 스마트폰 이용으로 스마트폰에 대한 현저성이 증가하고, 이용조절력이 감소하여 문제적 결과를 경험하는 상태이다. 한국정보화진흥원에서 매년 발간(2011년∼2018년)한 스마트폰 과의존 실태조사 보고서를 분석한 결과 스마트폰 과의존 위험군은 19.1%(2018년)로 매년 증가하고 있고, 특히 유아동과 60대, 청소년 및 성인은 여성, 유아동 및 60대는 남성, 학령별로는 여자 중학생, 부모가 위험군인 경우 유아동 및 청소년 자녀도위험군에 속하는 비율이 높아지는 것으로 나타났다.따라서 스마트폰 과의존은 심리적, 관계·행동적, 신체적 영향과 같은 다양한문제가 초래되는 등 정보화 역기능 현상이 심화되므로 예방 및 대응 필요성이더욱 증대되고 있다.
평균수직응력에 민감한 모재를 가진 기공체의 구성식과 기공생성모델
정현용,Jeong, Hyeon-Yong 대한기계학회 2000 大韓機械學會論文集A Vol.24 No.2
A macroscopic yield criterion for porous solids with pressure-sensitive matrices modeled by Coulomb's yield criterion was obtained by generalizing Gurson's yield criterion with consideration of the hydrostatic yield stresses for a spherical thick-walled shell and by fitting the finite element results of a voided cube. The macroscopic yield criterion is valid for negative mean normal stresses as well as for positive mean normal stresses. From the yield criterion, a plastic potential function for the porous solids was derived either for plastic normality flow or for plastic non-normality flow of pressure- sensitive matrices. In addition, the elastic relation, an evolution equation of the plastic flow stress of the matrices and an evolution equation of the void volume fraction were presented to complete a set of constitutive relations. The set of constitutive relations was implemented into a finite element code ABAQUS to analyze the material behavior of rubber-toughened epoxies. The cavitation and the deformation behavior were analyzed around a crack tip under three-point bending and around notch tips under four-point bending. In the numerical analyses, the cavitation of rubber particles was considered via a stress-controlled nucleation model. The numerical results indicate that a reasonable cavitation zone can be obtained with void nucleation controlled by the macroscopic mean normal stress, and a plastic zone is smaller around a notch tip under compression than under tension. These numerical results agree well with corresponding experimental results on the cavitation and plastic zones.
정현용 대한소화기학회 2004 대한소화기학회 춘계학술대회 Vol.2004 No.-
근간에 기능성 소화불량증의 증상 양상에 따른 병태생리에 대한 새로운 개념의 정립으로 멀지 않은 시기에 우수한 치료법이 개발될 것으로 기대된다. 하지만 현재의 치료는 증상에 따라서 위장관 운동 촉진제와 위산 분비 억제제의 경험적인 사용이 전부인 상태이다. H.pylori 감염과 기능성 소화불량증의 강한 연관 관계 가 입증되지 않았지만, 서구에서는 경제적인 측면을 고려한 우선적인 제균치료가 위내시경검사를 우선한다. 우리나라와 같이 위암의 빈도가 높고, H. pylori 감염율이 높으며 항생제 내성이 문제가 되는 경우는 우선적으로 위내시경검사를 해서 기질적인 소화불량증을 배제하는 것이 바람직하다. 일정 기간의 경험적 약물 치료에 반응이 없는 난치성 소화불량증의 치료는 더욱 어렵다. 식이 요소에 대해 주의를 환기시키고, 보다 강력 한 약물의 사용이나 복합 처방 및 새로운 약물들을 사용하며, 정신과 의사와의 협진 및 허브나 민간 요법을 고려한다.
상부소환관협착에 대한 Savary-Gilliard Dilatation의 치료효과와 안전성에 관한 관찰
정현용,육은주,임의혁,김병호,성자원,이기천,허승식,이헌영,김영건 충남대학교 의과대학 지역사회의학연구소 1992 충남의대잡지 Vol.19 No.2
For the patient with stenosis of upper digestive tract caused by either benign or malignant process, esophageal dilatation is an important therapeutic modality. We reviewed retrospectively 39 cases treated by Savary-Gilliard dilatation for upper digestive tract stenosis, and results were follows : (1) Dysphagia was improved in 95% of the patients. (2) Eight patients(20%) sufferd perforation, five of them were managed with conservative medical measures, others were managed operatively. (3) In the cases with benign stenosis dysphagia was not noticed for 8.8 months, but with malignant stenosis dysphagia was reappeared after 2.8 months despite concomitant chemoradiotherapy. In conclusion, Savary-Gilliard dilatation was an effective measure for symptome due to upper digestive tract stenosis, but more careful attention for perforation should be necessitated. Also another therapeutic modality for treatment of malignant stenosis was inevitable.