• 제목/요약/키워드: Risk function

검색결과 1,719건 처리시간 0.032초

Plastic hinge length for coupled and hybrid-coupled shear walls

  • Abouzar Jafari;Meysam Beheshti;Amir Ali Shahmansouri;Habib Akbarzadeh Bengar
    • Steel and Composite Structures
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    • 제48권4호
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    • pp.367-383
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    • 2023
  • A coupled wall consists of two or more reinforced concrete (RC) shear walls (SWs) connected by RC coupling beams (CBs) or steel CBs (hybrid-coupled walls). To fill the gap in the literature on the plastic hinge length of coupled walls, including coupled and hybrid-coupled shear walls, a parametric study using experimentally validated numerical models was conducted considering the axial stress ratio (ASR) and coupling ratio (CR) as the study variables. A total of sixty numerical models, including both coupled and hybrid-coupled SWs, have been developed by varying the ASR and CR within the ranges of 0.027-0.25 and 0.2-0.5, respectively. A detailed analysis was conducted in order to estimate the ultimate drift, ultimate capacity, curvature profile, yielding height, and plastic hinge length of the models. Compared to hybrid-coupled SWs, coupled SWs possess a relatively higher capacity and curvature. Moreover, increasing the ASR changes the walls' behavior to a column-like member which decreases the walls' ultimate drift, ductility, curvature, and plastic hinge length. Increasing the CR of the coupled SWs increases the walls' capacity and the risk of abrupt shear failure but decreases the walls' ductility, ultimate drift and plastic hinge length. However, CR has a negligible effect on hybrid-coupled walls' ultimate drift and moment, curvature profile, yielding height and plastic hinge length. Lastly, using the obtained results two equations were derived as a function of CR and ASR for calculating the plastic hinge length of coupled and hybrid-coupled SWs.

미국 해양기반기후해법 법안(Ocean Based Climate Solution Act, OBCSA)의 검토와 국내 해양기후변화 법제에 대한 시사점 (A Review of a Bill on the Ocean-Based Climate Solution Act (OBCSA) in the U.S and Implications for the Ocean Climate Change-Related Legal System in Korea)

  • 윤소라;이문숙
    • Ocean and Polar Research
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    • 제45권2호
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    • pp.71-87
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    • 2023
  • Climate change causes ocean warming, ocean acidification, sea-level rise, dynamic coastal risk, change of ecosystem structure and function, and degradation of ecosystem services. Not only that, but it has negatively impacted the well-being of people, society, and culture, including food security, water resources, water quality, livelihood, health, welfare, infrastructure, transport, tourism, recreation, and so on, especially by particularly degrading indigenous communities and generating an inequitable distribution of benefits and costs. As pointed out here, these adverse impacts of climate change on the ocean have been emphasized at the international and national levels. In contrast, the ocean field has been neglected in the climate change conversation for too long. However, since the UNFCCC COP 25, the ocean has been drawn into the discussion as a solution to address climate change. Moreover, the U.S. Congress recently unveiled a bill called the 'Ocean-Based Climate Solution Act, OBCSA' that reflects the new paradigm of the international regime. The comprehensive legislative bill includes elements related to climate inequity, a blue economy, and a community-led bottom-up policy mechanism, which will have a significant bearing on the ocean-climate legal system. Therefore, this study reviews the OBCSA and deduces implications with regard to the ocean-climate legal system in Korea.

Surgical Management and Long-Term Results of Rathke's Cleft Cyst

  • Seung-Ho, Seo;Kihwan, Hwang;So Young, Ji;Jung Ho, Han;Chae-Yong, Kim
    • Journal of Korean Neurosurgical Society
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    • 제66권1호
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    • pp.82-89
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    • 2023
  • Objective : Rathke's cleft cysts (RCCs) are nonneoplastic cysts. Most of them are asymptomatic and stable; when symptomatic, RCCs are surgically fenestrated and drained. However, the outcomes remain unclear. The authors evaluated the outcomes of RCC decompression. Methods : Between 2004 and 2019, 32 RCCs were decompressed in a single tertiary institution. The clinical characteristics, intraoperative findings, postoperative complications, and endocrinological and surgical outcomes were retrospectively reviewed. Patients who underwent sequential imaging at least twice and at least 12 months after surgery were included in the analysis. Results : Patients' mean age was 40.8±14.9 years, and 62.5% were women. The mean follow-up duration was 62.3±48.6 months. In 21 patients (65.6%), no residual cysts were identified on postoperative magnetic resonance imaging. Of the 18 patients with preoperative visual field defects, 17 (94.4%) experienced postoperative visual improvement. Postoperative complications included endocrinological deterioration in 11 patients (34.4%), permanent diabetes insipidus in 11 (34.4%), infection in four (12.5%), intrasellar hemorrhage in three (9.4%), and cerebrospinal fluid leak in two (6.3%). Follow-up images revealed cyst recurrence in nine patients (28.1%), an average of 20.4 months after surgery; in three patients, the cysts were symptomatic, and resection was repeated. Multivariable analysis revealed that postoperative endocrinological deterioration was the only independent factor associated with cyst recurrence (p=0.028; hazard ratio, 6.800). Conclusion : Our findings showed that although only cyst fenestration for decompression was performed to preserve pituitary function, more pituitary dysfunction occurred than expected. Besides, the postoperative hormonal deterioration itself acted as a risk factor for cyst recurrence. In conclusion, surgery for RCC should be more careful.

시그모이드 함수를 이용한 가스안전사업 효과의 발현시점 추정과 조정 (Estimation and Adjustment of Time Point in Manifestation of Gas Safety Project Effects using Sigmoid Functions)

  • 임현교;박건영
    • 한국안전학회지
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    • 제38권1호
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    • pp.70-77
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    • 2023
  • Gas has replaced coal or petroleum as primary fuel because of its convenience. However, gas has risk of fire, explosion, or poisoning. To reduce gas-related accidents, many strategic projects have been being carried based on 'Gas Safety Management Basic Plans' on a domestic scale. In spite of those projects, the gas-related accident rate did not decrease over past decades. Thus, this study was conducted to analyze the effectiveness of ongoing projects, and to find out ways to make improvements. Conventional statistical analyses on accident data published by gas-related institutions were not useful to determine meaningful attributes to predict future. Whereas, accident case analyses adopted in the present study discovered differences in the type of people and their unsafe acts for each gas type. Meanwhile, the overall average priority of projects was not high in the aspect of System Safety Precedence. If the current trend is maintained, with sigmoid functions, it can be estimated that mean annual accident rate will decrease by only 2.0% in the next two decades. To improve the current trend, the present study made conclusions as followings: (1) safety projects should be designed with careful consideration of accident traits including gas type, unsafe acts, and persons involved and (2) alternative strategies should include system considerations such as minimum hazard design and safety devices prior to mere education or training. To summarize briefly, the present state related with gas accidents highlights the necessity of a system-based multidisciplinary approach.

파킨슨병 노인의 낙상에 영향을 미치는 신체적, 심리적 요인 (Physical and Psychological Factors Affecting Fall in Elderly Patients with Parkinson's disease)

  • 김지연;변미경
    • 융합정보논문지
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    • 제12권3호
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    • pp.55-65
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    • 2022
  • 파킨슨병 노인은 낙상의 신체적, 정신적 위험요인을 가진 비율이 비 파킨슨병 노인에 비해 높아, 파킨슨병 노인의 낙상 경험 유무에 따라 낙상에 영향을 주는 신체적, 정신적 위험요인을 한국 노인 전체를 모집단으로 하는 국가 데이터를 이용하여 규명하였다. 2017년 보건복지부의 노인실태 자료조사를 이용한 2차 분석연구로, 파킨슨병 노인은 총 103명이었으며 결측값을 제외하고 총 96명의 대상자를 분석하였다. 파킨슨병 노인에게서 낙상에 가장 큰 영향을 미치는 요인은 IADL로 나타났으며, IADL은 운동 조절기능과 관련이 있다. 운동 조절기능의 저하는 일상생활에 필수적으로 요구되는 신체 움직임에 제약을 가하며 위급상황에서의 자기 보호적 행동까지도 영향을 미쳐 낙상에 영향을 미친다. IADL이 낙상에 영향을 줄 수 있다는 본 연구결과를 바탕으로 파킨슨병 노인의 낙상 예방 중재를 위한 다양한 운동요법을 제안할 수 있을 것이다.

시각장애인을 위한 보행 안내 스마트 안경 플랫폼 설계 (Design of Smart Glasses Platform walking guide for the visually impaired)

  • 이재범;장종욱;장성진
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2021년도 추계학술대회
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    • pp.320-322
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    • 2021
  • 세계적으로 고령 인구가 증가함에 따라 시각장애인의 비율 역시 증가하고 있으며, 여전히 안전상에 문제, 안내정보 부족 등 시각장애인이 외부 활동을 하는 데에 있어서 많은 제약이 존재한다. 이를 해결하기 위해 광학 문자 인식(OCR) 기능이 탑재된 스마트 안경 등 스마트 기기에 관한 연구가 활발히 진행되고 있다. 본 논문에서는 전방에 장애물을 인식해 음성으로 정보를 알려주고, 목적지까지 길을 안내해주는 시스템을 제안한다. 딥러닝 객체 인식 모델인 Yolo를 이용하여 계단, 라바 콘과 같은 위험요소를 장애물로 인식하고 음성으로 정보를 전달해주며, 길 찾기 API와 음성인식, TTS 라이브러리를 사용하여 입력한 목적지까지 음성으로 길 안내를 해줌으로써 시각장애인의 외부 활동 범위가 확대되는 효과를 기대할 수 있다.

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로블록스 메타버스 환경에서의스테가노그래피기반은닉통신기법 (A Steganography-Based Covert Communication Method in Roblox Metaverse Environment)

  • 윤도경;조영호
    • 정보보호학회논문지
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    • 제33권1호
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    • pp.45-50
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    • 2023
  • 세계 1위 메타버스 플랫폼인 로블록스(Roblox)의 경우, 30억개 이상의 가입 계정과 1억 5천만명이상에달하는월간 활성 이용자수(MAU)를 기록하고 있다. 이렇듯 메타버스에 대한 높은 관심에도, 메타버스 환경의사이버공격위험성과 보안에 관한 연구는 매우 부족하다. 따라서, 본 연구에서는 대표적인 메타버스 환경인 로블록스에서의스테가노그래피 기반 은닉통신 기법에 대해 연구하였다. 구체적으로, 로블록스 체험 환경을 통해 은닉 메시지를이미지에삽입하고체험 참가자(user)들의 단말기에 자동으로 해당 이미지가 저장된 후 은닉한 메시지 역시 성공적으로추출됨을실험을통해 확인하고 결과를 제시한다. 이를 통해, 메타버스 환경에서 은밀한 비밀 지령 전파, 스테가노그래피봇넷구축, 악성 Malware 대량 유포 등 다양한 사이버공격과 범죄에 악용될 가능성을 확인하고 알리고자 한다.

Supporting Resilience and the Management of Grief and Loss among Nurses: Qualitative Themes from a Continuing Education Program

  • Esplen, Mary Jane;Wong, Jiahui;Vachon, Mary L.S.
    • Journal of Hospice and Palliative Care
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    • 제25권2호
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    • pp.55-65
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    • 2022
  • Caring for patients with cancer is highly stimulating and rewarding, attracting health professionals to the field who enjoy the challenge of managing a complex illness. Health professionals often form close bonds with their patients as they confront ongoing disease or treatment impacts, which may be associated with multiple losses involving function and/or eventual loss of life. Ongoing exposure to patient loss, along with a challenging work setting, may pose significant stress and impact health professionals' well-being. The prevalence rates of burnout and compassion fatigue (CF) are significant, yet health professionals have little knowledge on these topics. A 6-week continuing education program consisting of weekly small-group video-conferencing sessions, case-based learning, and an online community of practice was delivered to health care providers providing oncology care. Program content included personal, organization and team-related risk and protective factors associated with CF, grief models, and strategies to mitigate against CF. Content analysis was completed as part of the program evaluation. In total, 189 participants (93% nurses) completed the program, which was associated with significant improvements in confidence and knowledge of CF and strategies to support self and team resilience. Qualitative themes and vignettes from experiences with the program are presented. Key themes included knowledge gaps, a lack of support related to CF and strategies to support resilience, organization-and team-based factors that can inhibit expression about the impacts of clinical work, the health professional as a "person" in caregiving, and the role of personal variables, self-skill practices, and recommendations for education and support for self and teams.

Super app marketplace 전략을 위한 소비자 유형화 - 쇼핑 성향을 중심으로 - (The classification of super app consumer for marketplace strategy - Focusing on the shopping orientations -)

  • 김해정;이영주
    • 복식문화연구
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    • 제31권3호
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    • pp.330-345
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    • 2023
  • This study aimed to categorize consumers using super app functional characteristics to identify demographic differences, and analyze shopping orientations by consumer type. This data can be used by fashion and beauty companies for product planning and marketing strategies. To categorize super app consumers, data were analyzed with SPSS v.26.0 software using frequency, factor, reliability K-mean cluster, and distributed analyses, one-way-ANOVAs, and Scheffe verification. Cross-analysis was conducted to correlate super app consumer types with demographic characteristics. One-way-ANOVAs and Scheffe verification were used to analyze the differences in shopping preferences between super app consumer groups. As a result of our analyses, super app consumers were classified into four types: the ration type, the low-use type, the multifunction type, and the habit type. There were statistically significant differences between these types in age, occupation, marital status, average monthly household income, and shopping impact factors. Five super app user shopping orientations were identified: brand pursuit, pleasure pursuit, trend pursuit, risk perception, and economic orientation. The differences in the preferred orientation between super app consumer types were found to be statistically significant. The majority of respondents were multifunction type consumers. This group used the super app most frequently and effectively. They also demonstrated the highest scores for all five of the shopping orientations. The classification of consumer types in this study will allow the fashion and beauty industries to utilize super apps for more targeted product design and marketing.

Future drought risk assessment under CMIP6 GCMs scenarios

  • Thi, Huong-Nguyen;Kim, Jin-Guk;Fabian, Pamela Sofia;Kang, Dong-Won;Kwon, Hyun-Han
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2022년도 학술발표회
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    • pp.305-305
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    • 2022
  • A better approach for assessing meteorological drought occurrences is increasingly important in mitigating and adapting to the impacts of climate change, as well as strategies for developing early warning systems. The present study defines meteorological droughts as a period with an abnormal precipitation deficit based on monthly precipitation data of 18 gauging stations for the Han River watershed in the past (1974-2015). This study utilizes a Bayesian parameter estimation approach to analyze the effects of climate change on future drought (2025-2065) in the Han River Basin using the Coupled Model Intercomparison Project Phase 6 (CMIP6) with four bias-corrected general circulation models (GCMs) under the Shared Socioeconomic Pathway (SSP)2-4.5 scenario. Given that drought is defined by several dependent variables, the evaluation of this phenomenon should be based on multivariate analysis. Two main characteristics of drought (severity and duration) were extracted from precipitation anomalies in the past and near-future periods using the copula function. Three parameters of the Archimedean family copulas, Frank, Clayton, and Gumbel copula, were selected to fit with drought severity and duration. The results reveal that the lower parts and middle of the Han River basin have faced severe drought conditions in the near future. Also, the bivariate analysis using copula showed that, according to both indicators, the study area would experience droughts with greater severity and duration in the future as compared with the historical period.

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