LiCl-KCl 용융염에서 퇴역 증기발생기 전열관(Alloy-600) 전해정련 전산해석

김평화,손성준,황일순 한국방사성폐기물학회 2015 한국방사성폐기물학회 학술논문요약집 Vol.2015 No.10

An Approximate Method for Buckling Analysis and Optimization of Composite Lattice Conical Panels Considering Geometric Parameters

김평화,박정선 한국항공우주학회 2023 International Journal of Aeronautical and Space Sc Vol.24 No.5

This paper proposes an approximate method for calculating the critical buckling load of conical composite lattice panels. The conical composite lattice panel consists of helical and hoop ribs and can be described by geometrical parameters. Using these geometric parameters, the critical buckling load of conical composite lattice panels under uniform compression is predicted. The present method is validated by comparing the critical buckling loads obtained under a simply supported boundary condition with those obtained by the finite element method. The results of the critical buckling load show good agreement between the present method and finite element analysis. A parametric study is performed using the present method to investigate the influence of the number of hoop and helical ribs on the critical buckling load. In the parametric study, the number of helical and hoop ribs is defined as design variables, and the critical buckling load is defined as the response. In addition, the present method is applied to the optimization of composite lattice conical panels using a genetic algorithm. The optimization of the panels is defined by minimizing the mass, while defining the critical load as the boundary condition. Therefore, the approximation method using geometric functions provides not only analysis of critical buckling loads for composite lattice panels but also a useful tool for optimal design.

Comparison of Radioembolization and Sorafenib for the Treatment of Hepatocellular Carcinoma with Portal Vein Tumor Thrombosis: A Systematic Review and Meta-Analysis of Safety and Efficacy

김평화,Sang Hyun Choi,김진형,박성호 대한영상의학회 2019 Korean Journal of Radiology Vol.20 No.3

Objective: To compare the safety and efficacy of radioembolization with that of sorafenib for the treatment of hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT). Materials and Methods: MEDLINE, EMBASE, and Cochrane databases were searched for studies reporting outcomes in patients with HCC and PVTT treated with radioembolization or sorafenib. Meta-analyses of cumulative overall survival (OS) and Kaplan-Meier survival rates according to the time to progression (TTP) and incidence of adverse events (AEs) were performed. Subgroup analyses were conducted on 1-year OS data. Results: Seventeen studies were identified (four involving radioembolization, 10 involving sorafenib, and three comparing both). Pooled OS rates were higher in the radioembolization group, notably at 6 months {76% (95% confidence interval [CI], 64–85%) vs. 54% (95% CI, 45–62%)} and 1 year (47% [95% CI, 38–57%] vs. 24% [95% CI, 18–30%]); TTP was also longer with radioembolization. In patients undergoing radioembolization, the proportion of patients with Eastern Cooperative Oncology Group status 0 (p < 0.0001), Child-Pugh A (p < 0.0001), extrahepatic metastasis (p = 0.0012), and a history of cancer treatment (p = 0.0048) was identified as a significant source of heterogeneity for the 1-year OS. Radioembolization was associated with a lower incidence of grade 3/4 AEs than sorafenib (9% [95% CI, 3–27%] vs. 28% [95% CI, 17–43%]). Conclusion: Compared with sorafenib, radioembolization is a safer and more effective treatment for HCC with PVTT and is associated with prolonged survival, delayed tumor progression, and fewer grade 3/4 AEs.

아동학대가 아동의 우울 및 공격성에 미치는 영향에 대한 수치심의 매개효과

김평화,윤혜미 한국아동권리학회 2014 아동과 권리 Vol.18 No.4

The purpose of this study is to examine the mediating effect of shame on the relationship among child abuse, children’s depression and aggression. Self- administered questionnaires were collected from 415 children in the fifth and sixth grades. The results showed that the experience of child abuse is significantly associated with both depression and aggression in children. Neglect was found to have the strongest influence among all types of abuse, followed by emotional abuse and physical abuse, on children's depression and aggression. It was also found that shame has a mediating effects on the relationships among child abuse and depression & aggression; specifically, perfect mediation was found with regard to emotional abuse, while partial mediation was noted with neglect. Implications of the study results are discussed. 본 연구는 학대피해경험이 아동의 수치심과 우울 및 공격성에 어떤 영향을 미치는지 살펴보고, 수치심이 우울과 공격성에 대한 학대피해경험의 영향을 매개하는지를 초등학교 5, 6학년 아동 415명을 대상으로 살펴보았다. 분석 결과 학대유형은 방임, 정서적 학대, 신체적 학대 순으로 우울에 영향을 미치는 것으로 나타났으며 수치심은 정서적 학대-우울에 대해서는 완전매개, 방임-우울에 대해서는 부분매개의 효과를 보여주었다. 아동학대피해경험과 수치심 및 공격성 간의 영향력을 살펴본 결과, 방임, 정서적 학대, 신체적 학대, 부부폭력 목격 순으로 아동의 공격성에 영향을 미치는 것으로 나타났으며 수치심은 공격성에 대한 정서적 학대의 영향을 완전매개, 방임의 영향을 부분매개하는 것으로 나타났다. 이 결과는 학대피해아동의 부적응에 수치심의 역할을 입증하고 있어 피해아동에 대한 치료적 접근에서 부정적 정서인 수치심을 심도있게 다루어야 함을 시사하고 있다.

풍력발전타워의 설계/시공 자립화 기술 개발 연구

김평화,강성용,박종섭,강영종,Kim, Pyung-Hwa,Kang, Sung-Yong,Park, Jong-Sup,Kang, Young-Jong 한국복합신소재구조학회 2015 복합신소재학회논문집 Vol.6 No.2

점진적 강성 저하 모델을 이용한 복합재 이중 볼트 체결부의 점진적 파손 해석 연구

김평화,김성민,도성철,윤동현,박정선 항공우주시스템공학회 2019 항공우주시스템공학회지 Vol.13 No.6

In this paper, progressive failure analysis is performed on composite joints widely used in various industries such as the aerospace industry. The analysis was conducted on single bolted joints to confirm its reliability and in succession on double-bolted composite joints as well to study the characteristics of progressive failure. Hashin failure criteria and EGDM (energy based gradual degradation model) were used for the analysis. Failure variables are defined by four failure modes, respectively. According to the variables, stiffness degradation has been calculated. As a result of comparing the test and analysis results of single-bolted joints, the error was below 5% and it showed that the analytical results are rather credible. Also, the parametric analysis consequences were obtained conducting the process-progressive failure analysis on the double-bolted composite joints considering edge-distance ratio (e/d ratio) and bolt spacing. 본 논문에서는 항공우주분야 등 여러 분야에서 사용되는 복합재 볼트 체결부에 대해 점진적 파손 해석을 수행하였다. 단일 볼트 체결 시편에 대한 해석을 통해 해석 방법에 대해 검증하고 이를 이용해 이중 볼트 체결 시편의 점진적 파손에 관해 연구하였다. 점진적 파손 해석을 위해 Hashin 파손 판정식과 에너지 기반 점진적 파손모델을 사용하였다. 복합재료의 4가지 파손모드에 대해 손상변수를 정의했다. 이에 따른 물성저하를 계산하였다. 단일 볼트로 체결된 시편에 대해 시험 및 점진적 파손해석을 수행하여 시험 및 해석결과를 비교한 결과 약 5% 이하의 오차로 해석의 신뢰성을 확인하였다. 이중 볼트 체결 시편에 대해 점진적 파손해석을 이용해 볼트 원공으로부터 모서리까지의 거리와 볼트 사이의 간격을 고려하여 이중 볼트 체결부에 대한 매개변수 분석을 수행하였다.

접착 요소를 이용한 단일 겹침 접착 체결부의 강도 예측

김평화,김명준,임승규,박정선 한국항공우주학회 2015 한국항공우주학회 학술발표회 논문집 Vol.2015 No.4

복합재료 구조물에서 접착제를 이용한 체결부는 파손에 취약한 부분이다. 따라서 접착 체결부에 대한 신뢰성 있는 강도 예측이 요구되며, 최근에는 접착 요소를 이용한 유한요소해석 기법이 적용되고 있다. 본 논문에서는 에폭시 접착제를 이용한 단일 겹침 접착 체결부의 시편 시험 및 유한요소해석을 바탕으로 접착 요소의 물성 및 정적 강도 예측에 관한 연구를 수행하였다. 접착 요소에 적용되는 파괴 모드별 접착 영역 모델의 물성 변화에 따른 체결부의 강도 특성을 분석하고, 이를 바탕으로 실제 시험 데이터와 유사한 파괴 거동을 예측하였다. 또한 접착 요소의 국부적 모델링 기법을 통하여 체결부의 실제 균열 진전 형태를 모사하였다. Adhesively bonded joint is the weakest part of composite structure. Futhermore, reliable strength prediction is required for adhesively bonded joint. Recently, the Cohesive Zone Model (CZM) is used to predict the strength of adhesive joint. This paper represents a prediction of cohesive element"s properties by test and finite element analysis for a single-lap joint bonded with an epoxy adhesive. We analyze strength characteristics of the single-lap joint due to change in properties of cohesive zone model determined for each failure mode. Also, a fracture behavior is predicted similar to the actual test data and crack growth behavior by using a local modeling technique of cohesive element.

[행복일기] 잠꼬대야, 고마워

김평화 샘터사 2010 월간 샘터 Vol.485 No.-

Prognostic factors related with outcomes in out-of-hospital cardiac arrest due to pesticide poisoning in South Korea: a nationwide population-based study

김평화,김재국,강구현,장용수,김원희,최현영,이윤재 대한응급의학회 2024 대한응급의학회지 Vol.35 No.1

Objective: The purpose of this study was to identify prognostic factors related to outcomes of out-of-hospital cardiac arrest caused by pesticide poisoning. Methods: This retrospective observational study used countrywide population-based data from the Out-of-Hospital Cardiac Arrest Surveillance of the Korean Centers for Disease Control and Prevention from January 2008 to December 2018. Adult out-of-hospital cardiac arrest (OHCA) patients (over the age of 18) poisoned by a pesticide who experienced cardiac arrest and a subsequent return of spontaneous circulation (ROSC) were included in the study. The primary outcome variables were prognostic factors related to survival at hospital discharge, and the secondary outcome variable was good neurological outcome (Cerebral Performance Categories 1 or 2) at hospital discharge. Results: Three hundred and three patients were enrolled in the study, and 48 (15.8%) survived until hospital discharge (the hospital discharge group), and 255 (84.2%) died in hospital (the in-hospital death group). Fifteen (4.9%) of the 303 study subjects had a good neurological outcome, and 288 (95.1%) had a poor neurological outcome. Multivariate logistic regression showed that sustained pre-hospital ROSC was significantly associated with survival to discharge (adjusted odds ratio [AOR]=3.186; 95% confidence interval [CI], 1.436-7.068; P=0.004) and good neurological outcome (AOR=8.945; 95% CI, 2.974-26.907; P≤0.001). Conclusion: Sustained pre-hospital ROSC is associated with a favorable outcome in cases of OHCA induced by pesticide poisoning.

한의치료를 받은 산모의 산후 6주간 증상에 대한 전향적 관찰 연구

김평화,김안나,장현철,이은희,Kim, Pyung-Wha,Kim, An-Na,Jang, Hyun-Chul,Lee, Eun-Hee 대한한방부인과학회 2017 大韓韓方婦人科學會誌 Vol.30 No.4

Objectives: This study aims to investigate the changes of women's postpartum symptoms, including their weights, edema index and quality of life (QOL) over the first six weeks after childbirth. Methods: The study participants were 31 postpartum women treated in the Dept. of Obstetrics & Gynecology, at Woo-Suk University Korean Medicine Hospital, from May 20th to August 5th, 2016. In the first 2 weeks of the postpartum period, the main data collection method was to interview each patient and write down all of their complaints, and additionally referring to each participant's PHR (Personal Health Records). At the 3rd, 4th, 5th and 6th week, the researcher interviewed participants by phone once a week. The participants' weight, edema index (ECW/TBW) and the quality of life (by EQ-VAS) were measured at 1st and 2nd week after childbirth. And, EQ-VAS was assessed once more at the 6th week after childbirth. As a last step, the participants responded to a survey on satisfaction regarding their postpartum care with Korean Medicine. Results: 1. In the 1st one week after childbirth, edema was the most frequent complaint. It was about joint pain of the upper limbs in the 2nd and 3rd weeks, sweating in the 4th week, and joint pain of the upper limbs in the 5th and the 6th weeks. 2. In the 1st two weeks of the postpartum period, the weight of the participants decreased from $66.33{\pm}9.30kg$ to $62.60{\pm}8.92kg$ (p<0.001) and the edema index ECW/TBW decreased from $0.399{\pm}0.010$ to $0.385{\pm}0.0 4$ (p<0.001). The EQ-VAS significantly improved from $61.77{\pm}17.72$ to $73.51{\pm}14.67$ (p<0.001). In the last 4-weeks of the postpartum period, the EQ-VAS decreased from $74.30{\pm}14.25$ to $73.63{\pm}13.35$, but this difference was not statistically significant (p=0.749). 3. Regarding the satisfaction with postpartum care with Korean Medicine, 60% of the participants responded that it was 'Excellent' and 40% said it was 'Good'. Conclusion: Over the entire postpartum period, the most frequent complaints were about musculoskeletal symptoms. Postpartum care with Korean Medicine treatments in the early postpartum period improves various postpartum symptoms and the quality of life for postpartum women.