Optimization of Rail Profile to Reduce Wear on Curved Track

최하영,이종수,이동형,송창용 한국정밀공학회 2013 International Journal of Precision Engineering and Vol.14 No.4

Wear is one of the most important factors affecting the structural life of railways. In urban railways, the curved track results in more wear than tangent track. Furthermore, the wear is frequently detected in a sharply curved track. Wear leads to reduction in the durability of railway as well as increase in the risk of derailment. In a recent study, a rail grinding was suggested to enhance the dynamic performance and extend the fatigue life of rails. This paper deals with an optimum design procedure for asymmetric rail head profile wherein the design profiles of high and low rails are simultaneously determined by minimizing the wear on curved tracks. The procedure employs a genetic-algorithm-based optimization method. The dynamic performances of a train such as lateral force,derailment and vertical force are evaluated using a rail vehicle dynamics program. The optimum design is validated by comparing the initial rail profile with the optimum profile in a full-scale wear test.

기관지확장증 동반 질환의 진단 및 관리

최하영,이현 대한내과학회 2022 대한내과학회지 Vol.97 No.4

Patients with non-cystic fibrosis bronchiectasis (hereafter referred to as bronchiectasis) often present with comorbidities. These comorbidities significantly impact symptoms, acute exacerbation, hospitalization, disease progression, and mortality in patients with bronchiectasis. Thus, accurate diagnosis and management of comorbidities associated with bronchiectasis are essential to reduce the disease burden of bronchiectasis. This review provides a state-of-the-art summary of key pulmonary and extra-pulmonary comorbidities associated with bronchiectasis, outlines clinical tools to quantify the prognosis of bronchiectasis, and suggests a workflow to diagnose and manage comorbidities associated with bronchiectasis.

Comparison of the outcomes of severe influenza A (H1N1) pneumonia in two tertiary referral hospitals in Korea : 2016 versus 2009

최하영,고의원,이현,홍상범,정치량 대한결핵 및 호흡기학회 2018 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.126 No.-

Background: In 2016 and 2009, there were pandemics of influenza A (H1N1) in Korea. We aim to investigate whether survival had improved in the setting of recent advances in intensive care unit (ICU) management. Methods: We conducted a retrospective analysis of patients with severe H1N1 pneumonia. Thirty-four and 28 patients were diagnosed in 2009 and 2016 respectively at two tertiary referral hospitals in Korea. Results: Of the patients, 28 were treated in 2009 and 34 were treated in 2016. In-hospital mortality was significantly lower in patients of 2016 compared to those of 2009 (18% vs. 44% p=0.028). Multivariable analyses revealed that treatment year and prone position were associated with greater likelihood of survival. Compared to the patients treated in 2009, those treated in 2016 were 3.3 times more likely to survive (adjusted hazard ratio, 3.26; 95% confidence interval, 1.17-9.09). Additionally, patients treated with prone positioning were 3.6 times more likely to survive (adjusted hazard ratio, 3.58; 95% confidence interval, 1.34-9.62). Conclusion: Treatment outcomes for severe H1N1 pneumonia improved from 2009 to 2016 in two tertiary centers in Korea. Our results suggest that ICU management of viral pneumonia has improved over this period. Active application of prone positioning may be beneficial for patients with severe H1N1 pneumonia.

소아 급성골수성백혈병에서 공여자 유형에 따른 조혈모세포이식 결과

최하영,김건,이우진,최준식,백희조,국훈 대한소아혈액종양학회 2016 Clinical Pediatric Hematology-Oncology Vol.23 No.2

Background: The aim of this study was to compare the outcomes of children with acute myeloid leukemia (AML) who received stem cell transplantation from different donor groups. Methods: This study included 37 pediatric AML patients who received allogeneic stem cell transplantation from March 1996 to December 2012 at Chonnam National University Hospital and Chonnam National University Hwasun Hospital. The overall survival (OS), event-free survival (EFS), cumulative incidence (CI) of graft versus host disease (GvHD), relapse and transplant-related mortality (TRM) were compared between different donor groups. Results: Transplant donor groups included matched sibling donor (MSD, n=15), unrelated donor (URD=13), unrelated umbilical cord blood (UCB, n=7), or haploidentical donor (HD, n=2). Twenty-six patients survived with a median follow-up of 7.3 years. The 7-year EFS rates were 80.0±10.3% in MSD, 69.2±12.8% in URD and 57.1±18.7% in UCB, and 0% in HD, respectively (P=0.019). The CI of relapse at 5 years was 20.0%, 15.4%, 33.3%, 50%, respectively (P=0.721). The CI of TRM at 2 years was 0%, 15.4%, 16.7%, 50.0%, respectively in each donor group (P=0.017). The CI of grade II-IV acute and extensive chronic GvHD were higher in UCB (P=0.003, P=0.020, respectively). There were no significant differences in OS, EFS, and CI of TRM and relapse between allele-mismatched URD and UCB. Conclusion: Despite the limitation of small number of patients, the comparable outcome of pediatric AML patients transplanted from alternative donor with those transplanted from MSD are encouraging. Especially, if a matched donor is not available, allele-mismatched URD or UCB transplant may offer the advantage of prompt availability for patients who urgently require transplantation.

성인 기관지확장증 약물치료의 최신지견

최하영,이현,나승원,오연목 대한의사협회 2020 대한의사협회지 Vol.63 No.8

Bronchiectasis refers to abnormal dilatation of the bronchi, which leads to the failure of mucus clearance and increased risk of infection. Pharmacotherapy for stable bronchiectasis includes oral or inhaled mucoactive agents, anti-inflammatory therapy, inhaled bronchodilators, long-term antibiotics, and long-term macrolide treatment. Among them, mucoactive agents are the most common adjunctive agents to airway clearance techniques. When patients with impaired lung function suffer from dyspnea, inhaled bronchodilators may be prescribed to relieve the symptom. Long-term macrolide treatment has been proven to prevent exacerbation in patients with frequent bronchiectasis exacerbation. If exacerbation occurs despite the above mentioned treatments, one or two weeks of antibiotics should be prescribed to cover respiratory bacteria that include Pseudomonas aeruginosa. Because evidence supporting the use of pharmacotherapy for bronchiectasis is weak, further research is warranted.

S-640 경피적관상동맥 중재술로 치료한 심혈관 매독 1예

최하영,유시내,이세환,전민혁 대한내과학회 2016 대한내과학회 추계학술대회 Vol.2016 No.1

46세 남자 환자가 2달전부터 발생한 운동시 흉통을 주소로 내원하였다. 흡연력은 있었으나 다른 관상동맥질환의 위험인자는 없었다. 혈액검사에선 적혈구 침강속도 74 mm/hr, C-반응성단백 23.15 mg/L로 상승되어 있었다. 심전도에서는 우각차단이 관찰되고 심초음파에선 좌심실박출률이 50%로 감소되었으나 국소벽운동장애는 없었다. 원인 감별을 위해 심혈관 컴퓨터단층촬영을 시행하였고 좌주관상동맥 입구의 90%, 우관상동맥입구의 85% 협착소견이 관찰되었으나 말단 관상동맥의 협착은 관찰되지 않았다. 혈관조영술을 시행한 결과, 좌쇄골하동맥, 좌목동맥, 우신장동맥의 입구에도 협착소견을 보였고 좌주관상동맥과 우관상동맥의 협착에 대해서는 스텐트 삽입술을 시행하였다. 입원시 시행한 RPR 정량 검사 양성으로 매독 추가 혈청검사를 진행한 결과, RPR역가1:128, TPHA역가1: 5120, FTA-ABS IgM,IgG 양성소견을 보였다. 병력을 재확인결과, 10년전 성기 궤양이 있어 페니실린 근육주사를 1회 맞은 적이 있다고 했다. 뇌척수액 검사에서, 백혈구 92/mm3, 단백 44.73 mg/dl, 당 73 mg/dl, 뇌척수액 RPR 1:4 관찰되었다. 혈청검사와 영상검사를 고려하여 매독성 대동맥염과 신경매독으로 진단하였다. 스텐트 삽입술 시행 후 흉통은 호전되었고, 신경매독치료를 위해 2주간 potassium penicillin G 2400만 단위를 정주 투여한 뒤 퇴원하였다. 15개월 뒤 혈관조영술 추적검사결과, 재협착소견은 관찰되지 않았다. RPR역가1:64, 뇌척수액 재검결과 백혈구7/mm3, 단백31.98 mg/dl, 당68 mg/dl, 뇌척수액 VDRL과 RPR 음성이었다. 치료 후 6개월 이상 경과되었으나 RPR 역가가 4배 이상 감소하지 않아 치료반응이 미흡하다 판단하고 Benzathine penicillin G 240만 단위를 1주 간격으로 3회 근육 주사하였고, 6개월뒤 뇌척수액 검사 추적검사를 할 계획이다. 매독에 의한 관상동맥 입구 협착을 관상동맥 중재술로 치료한 증례가 외국에서 소수 보고된 바가 있으나 3개월 만에 재협착 발생하여 관상동맥 우회술이 우선적인 치료로 추천되었다. 저자들은 중재술로 15개월째 재협착 없이 성공적으로 치료한 매독성 대동맥염 증례를 보고하는 바이다.

中共에 있어서의 '紅'과 '專'에 관한 小考

崔夏榮 건국대학교 1982 政法論叢 Vol.17 No.1

『인간복제에 관한 철학적 성찰』,

최하영 건국대학교 몸문화연구소 2014 건국대학교 몸문화연구소 콜로키움 발표자료 Vol.2014 No.4

연관규칙분석을 활용한 융합 기술 기회 발굴 방법론

최하영,고남욱,윤장혁 대한산업공학회 2015 대한산업공학회 추계학술대회논문집 Vol.2015 No.11

이종산업에 속한 기술들의 효과적인 결합은 산업을 융합하는 새로운 기술개발의 기회로 작용할 것이다. 본 연구에서는 기업의 보유역량을 기반으로 산업간 융합을 지원하는 기술기회 창출 방법론을 제시한다. 제시되는 방법론은 연관 규칙 분석(Association Rule Mining)을 활용하여 미국 특허청에 2009-2013년에 등록된 110만여 건의 특허들이 지니는 IPC간 연관규칙에 대해 산업간 융합패턴을 분석하였다. 이를 바탕으로 기업의 보유기술에 대응하는 IPC들을 기반으로 융합기술을 정의하고 이를 위한 요구 기술들을 파악할 수 있도록 한다. 본 연구는 기업의 기술 영역 확장을 위해 활용될 수 있으며, 나아가 특허 창출에 활용 될 것으로 기대된다.

『작은 아씨들』에서 ‘들’을 사유하다: 그레타 거윅의 <작은 아씨들>

최하영 도서출판여이연 2021 여성이론 Vol.- No.44