• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.304-304
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• 2017

In semi-arid countries such as Namibia, the flooding unexpectedly happens in a rainy season, causing losses in the yield of upland-adapted cereal crop. In flooding conditions, rice roots sequentially form aerenchyma and a barrier to radial oxygen loss (ROL), and oxygen is released into the rhizosphere near the root tips. Iijima et al. (2016) and Awala et al. (2016) reported that close mixed-planting with rice can mitigate the flood stress of co-growing upland-adapted cereal crop by modifying their rhizosphere microenvironments via the oxygen released from the rice roots. Moreover, by using the model system of hydroponic culture, it was confirmed that oxygen from rice roots was transferred to co-growing upland-adapted cereal crop in close mixed planting system (Kawato et al., 2016). However, it is not sure whether the ability of oxygen release varies among rice cultivars, because Kawato et al. (2016) used only one japonica cultivar, Nipponbare (Oryza sativa). The objective of this study was to compare the ability of oxygen release in rhizosphere among rice cultivars. The experiment was conducted in a climate chamber in Kindai University. We used 10 rice cultivars from three different rice species (O. sativa (var. japonica (2), var. indica (3)), Oryza glaberrima Steud. (2) and their interspecific progenies (3)) to compare the ability of oxygen release from the roots. According to the method by Kawato et al. (2016), the dissolved oxygen concentration of phase I (with shoot) and phase II (without shoot) were measured by a fiber optic oxygen-sensing probe. The oxygen released from rice roots was calculated from the difference of the measurements between phase I and phase II. The result in this study indicated that all of the rice cultivars released oxygen from their roots, and the amount of released oxygen was significantly correlated with the above-ground biomass (r = 0.710). The ability of oxygen release (the amount of the oxygen release per fresh root weight) of indica cultivars (O. sativa) tended to be higher as compared with the other cultivars. On the other hand, that of African rice (O. glaberrima) and the interspecific progenies tended to be lower. These results suggested that the ability of oxygen release widely varies among rice cultivars, and some of indica cultivars (O. sativa) may be suitable for close mixed-planting to mitigate flood stress of upland-adapted cereal crop.

• 의료법학
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• 제15권2호
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• pp.123-163
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• 2014

As results of analyzing judicial precedents about infection in hospitals in connection with mistakes and causality in medical litigations shows that the Mitigation of Law Principles To Prove responsibility in medical litigation has not been able to play its role compared to its intended purposes. And Major sentiment from those judgments is that a mistake can't be proved only by the fact that certain infection in hospital occurred in connection with hospital infection. Therefore, the number of indirect facts to deny estimation is overwhelmingly high. Like this, especially for hospital infection which is difficult to prove indirect facts themselves to estimate mistake, major sentiment from those judgments have a problem that impute sharing of losses caused by hospital infection to patient. In accordance with the Principles of equitable and proper sharing of losses, it's required to prepare legal interpretation and theoretical methods to largely mitigate patient's responsibility to prove medical mistakes compared to other medical litigations in connection with existing Mitigation of Law Principles To Prove responsibility and conventional theory of estimation. In connection with this, the results of review that duty of safety management in hospital infection cases can be the base of conversion of proving responsibility, the duty that prevent hospital infection, corresponding the duty of safety management in hospital infection is not conventional duty of safety management based on duty of good faith but secondary obligation of medical contract. The breach of duty preventing hospital infection is the violation of medical contract, but there is no logical necessity that convert proving responsibility from the obligation of contract itself. Therefore, the duty of preventing hospital infection from the obligation of medical contract, corresponding the duty of safety management in hospital infection cases cannot be the base of conversion of proving responsibility alone. But, it's still required to conversion of proving responsibility in hospital infection, we need further studies on cases of Germany which applies legal estimation of proving responsibilities in hospital infection.

• 조명전기설비학회논문지
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• 제13권2호
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• pp.88-94
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• 1999

이 논문은 염가형 마이크로프로세서를 사용한 고효율 인버터 안정기에 관해서 기술한다. 인버터 안정기내의 고속의 스위칭 주파수로 인한 심각한 스위칭 손실과 EMI문제를 위해서 소프트-스위칭 기술을 제안한다. 또, 주위온도에 따라 형광 램프의 점등특성을 개선시키기 위한 온도검출 회로와 기동접압 제어회로, 역률개선, 램프의 수명연장 및 스위칭손실경감을 위한 소프트 스위칭 회로의 채용은 형광램프용 안정기로서 매혹적인 특성을 제공한다. 본 연구에서는 이상과 같은 특성개선을 위한 인버터 안정기의 동작과 제어방법을 자세히 제시하고, 이를 입증하기 위한 실험을 했다. 실험결과, 입력전류의 낮은 종합 고조파 왜율(4.8%)과 램프전류의 높은 역률(98%) 및 $-40^{\circ}C$에서도 기동이 원활한 우수한 특성을 얻을 수 있다.

• 한국환경복원기술학회지
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• 제23권2호
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• pp.33-47
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• 2020

With population losses and stagnant or depressed economies, the local governments embrace shrinkage and accept having a significantly smaller population. Both the initial and ongoing causes of shrinkage hold dramatic effects on the city and its remaining residents. In this context, vacant land increases as an overabundance of unused infrastructure is demolished and municipalities become burdened with increasing maintenance costs of this land. The result is that vacant land often experiences minimal management relative to social norms and have chance to provide a setting for ecological processes with urban rightsizing strategy. Therefore, urban ecosystems undergo major shifts in structure and function. We need to better understand the possibilities of where and how much of houses and land will be abandoned to assist land planners and policymakers to mitigate conflict between optimal ecological and sociological outcomes. This article, therefore, aims to identify distributional characteristics of vacant houses and lands with case study of Mokpo. The study found and verified affecting factors of vacant houses and lands by type through the use of a Maxent model and spatial data that explained housing choice and preference theory. We can predict the vacancies with the spatial variables such as land price, the population ratio over 65, and the distance from security facility. Based on the analysis, the ways of managing housing and land vacancy for sustainable development and ecological restoration method are discussed.

• Smart Structures and Systems
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• 제14권5호
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• pp.847-867
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• 2014

There are continuous efforts to mitigate structural losses from earthquakes and manage risk through seismic risk assessment; seismic fragility curves are widely accepted as an essential tool of such efforts. Seismic fragility curves can be classified into four groups based on how they are derived: empirical, judgmental, analytical, and hybrid. Analytical fragility curves are the most widely used and can be further categorized into two subgroups, depending on whether an analytical function or simulation method is used. Although both methods have shown decent performances for many seismic fragility problems, they often oversimplify the given problems in reliability or structural analyses owing to their built-in assumptions. In this paper, a new method is proposed for the development of seismic fragility curves. Integration with sophisticated software packages for reliability analysis (FERUM) and structural analysis (ZEUS-NL) allows the new method to obtain more accurate seismic fragility curves for less computational cost. Because the proposed method performs reliability analysis using the first-order reliability method, it provides component probabilities as well as useful byproducts and allows further fragility analysis at the system level. The new method was applied to a numerical example of a 2D frame structure, and the results were compared with those by Monte Carlo simulation. The method was found to generate seismic fragility curves more accurately and efficiently. Also, the effect of system reliability analysis on the development of seismic fragility curves was investigated using the given numerical example and its necessity was discussed.

• 한국시스템다이내믹스연구
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• 제15권4호
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• pp.5-28
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• 2014

국제통상을 하는 기업은 위험 선호도에 따라 금융시장을 통해 외화자산 혹은 외화부채의 헷징(hedging)을 목적으로 파생금융상품을 쉽게 구매할 수 있다. 파생금융상품 시장은 투자와 헷지의 필요에 따라 급속도로 성장해왔다. 기업은 금융 파생금융상품을 통해 환위험 관리를 하면서 위험을 헷징한다. 기초자산을 헷징할 때는 환노출 완화전략으로 헷징이 효과적일 수 있다. 하지만 파생상품을 통한 이익에 대한 욕심과 예상치 못한 환율 변동이 발생할 때 기업에 상당한 위험을 초래할 수도 있다. 본 논문은 환위험을 다루는 파생상품에 내재된 구조적인 위험을 시스템다이내믹스 관점에서 분석하고 있다. 대표적인 파생금융상품인 KIKO는 구조적인 위험 요인 때문에 금융위기에 크나 큰 손실을 끼쳤다. 본 논문에서는 KIKO의 구조적 위험 요인을 모델링하고 실제 사례를 통해 검증하여 파생금융상품의 시스템 구조를 파악하고 내재되어 있는 구조적 위험을 밝혔다.

• 한국해양환경ㆍ에너지학회지
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• 제6권2호
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• pp.16-27
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• 2003

해상에 유출된 유류의 생물정화방법은 자연상태로 존재하고 유류분해능력이 있는 박테리아, 균류 또는 효모와 같은 토착미생물의 환경요인을 최적화하거나, 병원성 또는 유전자조작미생물을 제외한 특별한 환경정화능력을 가진 미생물을 오염된 지역에 투입하여 유류오염물질을 자연적으로 분해함으로써 오염된 환경을 원래의 상태로 회복시키는 기술이다. 현재 우리나라규정에는 해양오염사고시 생물정화제제를 사용할 수 있는 제도적인 근거가 마련되어 있지 않아 실제사용 뿐만 아니라 관련 기술개발에 있어 많은 제약이 따르고 있다. 본 연구에서는 생물정화제제의 개발과 활용을 위해 관련규정에 대한 법률적 개정방향을 제시하였고 사람의 건강과 생태계의 유해한 성분을 포함하고 있는지 혹은 발생가능성이 여부를 확인하기 위하여 4단계의 생물정화제제 성능시험방법, 검정기준 및 형식승인절차를 제시하였다. 1, 2단계의 절차를 통해 생물급성독성 및 유류분해성능을 평가하여 형식승인을 여부를 결정하고 3, 4단계 절차를 통해 현장적용 가능성을 평가하는 단계로 구분하였다.

• Nuclear Engineering and Technology
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• 제21권1호
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• pp.1-11
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• 1989

원자로 정지동안에도, 잔열제거계통은 그 기능이 계속 유지되어야 하나, 실제로 가압 경수로에서 냉각상실고가 많이 발생되어 있다. 본 논문은 원자로 정지중의 냉각기능상실을 예방하고, 또한 냉각기능상실로 인한 노심손상의 중대성을 완화시키기 위한 대책을 강구하기 위한 시도로서, 전형적인 가압경수로에 대한 사고/고장 수목과 운전원실수 확률을 위한 HCR 모델, 초기 사상의 빈도를 위한 2단계 bayesian 방법 및 고장난 계통의 회복 활률을 위한 계단함수 모델 등을 이용한 원자로 정지 위해도 모델을 개발하여, 잔열제거계통의 신뢰도를 분석하였다. 그 결과는 원자로가 정지 중일 때의 위해도가 운전중일 때 이것에 비해 별로 낮지 않은 것으로 나타났으며, 몇 가지의 설계개선을 통하여 냉각기능상실로 인한 노심 손상확률을 상당히 낮출 수 있는 것으로 나타났다.

• Structural Engineering and Mechanics
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• 제70권2호
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• pp.169-178
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• 2019

The replacement of damaged components is an important task for long-span bridges. Conventional strategy for component replacement is to close the bridge to traffic, so that the influence of the surrounding environment is reduced to a minimum extent. However, complete traffic interruption would bring substantial economic losses and negative social influence nowadays. This paper investigates traffic control technologies without interruption for component replacement of long-span bridges. A numerical procedure of traffic control technologies is proposed incorporating traffic microsimulation and site-specific data, which is then implemented through a case study of cable replacement of a long-span cable-stayed bridge. Results indicate traffic load effects on the bridge are lower than the design values under current low daily traffic volume, and therefore cable replacement could be conducted without traffic control. However, considering a possible medium or high level of daily traffic volume, traffic load effects of girder bending moment and cable force nearest to the replaced cable become larger than the design level. This indicates a potential risk of failure, and traffic control should be implemented. Parametric studies show that speed control does not decrease but increase the load effects, and flow control using lane closure is not effectual. However, weight control and gap control are very effective to mitigate traffic load effects, and it is recommended to employ a weight control with gross vehicle weight no more than 65 t or/and a gap control with minimum vehicle gap no less than 40 m for the cable replacement of the case bridge.

• 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.