• Earthquakes and Structures
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• 제13권5호
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• pp.443-454
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• 2017

When eccentrically braced steel frames (EBFs) are in the desired failure mode, links yield at each layer and column bases appear plastically hinged. Traditional design methods cannot accurately predict the inelastic behavior of structures owing to the use of capacity-based design theory. This paper proposes the use of performance-based seismic design (PBSD) method for planning eccentrically braced frames. PBSD can predict and control inelastic deformation of structures by target drift and failure mode. In buildings designed via this process, all links dissipate energy in the rare event of an earthquake, while other members remain in elastic state, and as the story drift is uniform along the structure height, weak layers will be avoided. In this condition, eccentrically braced frames may be more easily rehabilitated after the effects of an earthquake. The effectiveness of the proposed method is illustrated through a sample case study of ten-story K-type EBFs and Y- type EBFs buildings, and is validated by pushover analysis and dynamic analysis. The ultimate state of frames designed by the proposed method will fail in the desired failure mode. That is, inelastic deformation of structure mainly occurs in links; each layer of links involved dissipates energy, and weak layers do not exist in the structure. The PBSD method can provide a reference for structural design of eccentrically braced steel frames.

• 한국해양공학회지
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• 제31권4호
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• pp.299-307
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• 2017

The design of the mooring line to maintain the position of an offshore structure in rough marine environments is recognized as a very important consideration. Conventional fatigue evaluation of a mooring line was performed by considering the tensile force acting on the mooring line, but the mooring line broke after 238 days in the girassol area even though the expected fatigue life was expected to be longer. The causes of this event are known to be due to OPB/IPB (out-of-plane bending/in-plane bending) caused by chain link friction due to the excessive tensile strength of the mooring line. In this study, three models with different boundary conditions were proposed for fatigue analysis of a mooring line considering OPB/IPB. Interlink stiffness was calculated by nonlinear structure analysis and a stress concentration factor was derived. In addition, the sensitivity of interlink stiffness according to the magnitude of tensile force, large deformation effect, and coefficient of friction was analyzed, and the effect of critical elastic slip and bending moment calculation position on interlink stiffness was confirmed.

• 한국기계가공학회지
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• 제20권9호
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• pp.42-47
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• 2021

A one-touch descending lifeline that can easily be installed and rapidly evacuated in the event of a fire accident in high-rise buildings was proposed to overcome difficulties of conventional descending lifeline such as complex installation methods and procedures. However, this lifeline exhibits limitations such as restrictions in installation location and large apparatus size. Therefore, this paper proposes a sliding-type descending lifeline, which has a similar operation to that of current one-touch descending lifeline and solves the aforementioned limitations. A double square link mechanism including a sliding four-bar linkage is proposed and the descending lifeline support is redesigned to unfold in two different planes, allowing 3D movement. Additionally, the shape of the support frame is designed to obtain two attachment surfaces that can be attached to a wall, irrespective of the angle between the window and the inner wall. FEA analysis using ABAQUS is performed to ensure that the robustness of the presented support complies with the Fire Control Act Enforcement Decree. Finally, the feasibility of the proposed sliding one-touch descending lifeline is verified through fabrication.

• 한국환경보건학회지
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• 제49권3호
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• pp.129-133
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• 2023

Background: With the rise in global mobility, aircraft indoor air quality has become a significant public health concern. This study focuses on the health implications of increased travel and bleed air-air drawn from aircraft engines for cabin pressurization and air conditioning. Objectives: This research aims to review the potential health effects related to exposure to aircraft cabin air, particularly the effects of bleed air during fume events. Methods: We conducted a literature review of existing studies on aircraft cabin air quality. We focused on both the immediate and health effects of exposure to cabin air, particularly those related to bleed air contaminants. Results: The review found a possible link between exposure to aircraft cabin air and certain health issues, especially in cabin crew and frequent flyers. There was an increased incidence of respiratory and neurological symptoms related to bleed air exposure. However, the cumulative health effects of frequent air travel remain inconclusive due to limited data. Conclusions: This study highlights the need for improving air quality in aircraft to protect public health. While further research is needed to understand the cumulative effects of frequent air travel, the reduction of exposure to bleed air contaminants should be a priority. These findings underline the need for regulatory changes and technological improvements in aircraft cabin air quality.

• 생태와환경
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• 제39권4호통권118호
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• pp.424-434
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• 2006

박테리아-동물플랑크톤의 영양적 관계와 이에 미치는 요인들을 파악하기 위하여 2005년 4월부터 12월까지 팔당호 생태계의 영양상태가 다른 팔당댐앞과 경안천 두 지점을 선정하여 동물플랑크톤의 여과율과 박테리아의 C-flux를 분석하였다. 동물플랑크톤은 소형 (Microzooplankton, MICZ: 60-200 ${\mu}m$)과 대형동물플랑크톤(Macrozooplankton, MACZ: >200 ${\mu}m$)으로 구분하여 각 그룹에 대하여 별도로 섭식률을 조사하였다. 두 지점에서 박테리아 밀도와 계절적 변화양상은 유사하게 나타났다. 동물플랑크톤은 두 지점 모두 윤충류(Brachionus, Keratella, Polyathra)가 수적으로 크게 우점하였으나, 탄소생물량은 지각류(Daphnia)가 가장 높았다. 동물플랑크톤은 봄에 높은 밀도와 탄소생물량을 보였고 여름철 집중강우 시기를 기점으로 크게 감소하였다. 지점별로는 경안천에서 상대적으로 높은 탄소생물량이 나타났다. 박테리아에 대한 동물플랑크톤 여과율은 팔당댐앞에서 봄, 가을철에 높고 여름철에 낮게 나타나는 계절에 따른 변화가 명확하게 나타난 반면, 경안천에서는 팔당댐앞과는 달리 여름철에 높게 나타났다. C-flux는 두 지점 모두 봄철과 가을철에 높게 나타났다. 군집여과율과 박테리아 C-flux는 MACZ가 MICZ보다 높았고, 그 정도는 경안천에서 더 높게 나타났다. 여름철의 집중강우로 인한 짧은 체류시간과 수체의 교란이 동물플랑크톤의 섭식에 영향을 미치는 것으로 파악되었다.

• Asia pacific journal of information systems
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• 제22권4호
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• pp.51-73
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• 2012

Social network services based on openness, connectedness, and mass participation are reshaping many aspects of how companies conduct business and create value for their customers. For instance, Facebook and Twitter are expected to play a pivotal role as a new communication channel through which companies-forge close relationships with their customers for co-creation of value for mutual benefits. Given the potential of social network services, it is not surprising that many companies have strategically invested in social network services to reach out to customers. Despite the growing interest in social network services as a platform to connect companies and their customers, few guidelines exist about how managers can effectively utilize social network services in forging relationships with their customers. As such, scholars should pay greater attention to how firms can successfully develop relationships with their customers on social network services. In particular, this study employs the S-O-R (stimulus-organism-response) framework as a theoretical lens to develop a research model that explains customers' participation in the value co-creation platform that companies opened on Twitter. According to the S-O-R framework, certain types of individuals' behaviors can be best understood based on a causal link from environmental stimulus to organism, and response. We apply the S-O-R framework to understand how ubiquitous connectivity (stimuli) can influence customers' experience (organism) with companies on Twitter, which in turn influence their participation behavior (response). Two steps have been undertaken to empirically test the research model. First, we conducted a content analysis of tweets written by customers who follow companies on Twitter. As a result, we found event/promotion participation, company support, and giving feedback as three specific types of customer participation behavior. Second, we conducted a web-based survey to test research hypotheses in the research model. Participations in the survey were solicited to customers who followed companies on Twitter. As a result, a total of 115 respondents have completed the survey. Data were analyzed using the partial least square (PLS) technique. The results of data analysis suggest that ubiquitous connectivity (stimuli) had strong positive effects on perceive usefulness, perceived enjoyment, and perceived intimacy (organism). Perceived intimacy showed positive effects on customer participation behavior (response), such as event participation, company support, and giving feedback. Perceived enjoyment was found to have strong positive effects on company support and giving feedback. On the other hand, perceived usefulness did not have significant impacts on the three types of customer participation behavior.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제5권12호
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• pp.455-462
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• 2016

무선 센서 네트워크는 센서 필드 상의 이벤트에 관한 데이터를 소스로부터 싱크로 수집하기 위해 연구되어왔다. 멀티패스 라우팅은 노드나 링크 단절에 의해 소스에서 싱크로의 패스가 종종 손실되는 문제에 대해 신뢰성 있는 데이터전송을 위한 매력적인 방안 중 하나이다. 사람이나 동물 혹은 차량 등과 같은 모바일 이벤트 상황에서, 소스는 이 모바일 이벤트의 이동에 따라 연속적으로 소스가 발생할 수 있다. 따라서 멀티패스 라우팅에서 모바일 이벤트의 상황은 새로운 도전 과제를 제시한다. 그러나 기존의 멀티패스 라우팅 연구는 주로 소스들에서 정적인 싱크로 효율적인 멀티패스 구성과 패스 단절에 대한 빠른 멀티패스 재구성에 초점을 두었다. 따라서 이전 멀티패스 라우팅 프로토콜은 모바일 이벤트에 의해 발생하게 되는 연속적인 각각의 소스들이 소스에서 싱크로 각각의 멀티패스를 필요로 한다. 이는 이전 방안이 소스의 수에 비례하여 멀티패스 구성비용이 증가게 한다. 따라서 우리는 모바일 이벤트에 의해 연속적으로 발생하게 되는 소스를 지원하는 효율적인 멀티패스 라우팅 프로토콜을 제안한다. 제안방안에서 이전 소스에서 만들어 놓은 기존의 멀티패스를 이용함으로써, 새로운 소스가 효율적으로 재구성을 할 수 있다. 이를 위해, 제안방안은 지역적 멀티패스 재구성, 광역적 부분 멀티패스 재구성, 광역적 전체 멀티 패스 재구성의 세 방안 중 하나를 선택한다. 이 선택을 위해 우리는 멀티패스 재구성 비용과 데이터 포워딩 비용의 합을 계산하는 분석적인 에너지 소비 비용 모델을 제시한다. 시뮬레이션 결과 모바일 이벤트의 상황에서 멀티패스 라우팅을 할 때 제안방안이 기존의 방안보다 우수한 성능을 보였다.

• 한국콘텐츠학회논문지
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• 제16권10호
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• pp.766-779
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• 2016

본 연구는 세월호 참사 보도에 드러난 '가상성'을 중심으로 매개된 현실과 실제 현실의 간극을 조명하고자 기획되었다. 방송기자연합회 저널리즘 특별위원회는 한국 언론의 세월호 보도 양상을 가리켜 저널리즘의 침몰이라고 명명할 만큼 세월호 보도는 현실 반영에 커다란 문제점을 드러냈다. 언론 보도의 가상성이 문제가 되는 것은 실제 현실보다 보도된 현실, 즉 매개 표상들을 더욱 많이 접촉하고 경험할 때, 수용자는 '실제 현실'에 근거하여 행동하기보다는 '매개된 현실'로부터 받아들인 것을 실제 상황이라 여기고 이에 근거해 반응한다는데 있다. 많은 연구에서 매체의 수용자들은 매개현실을 실제 외부세계로 받아들이는 것으로 관찰된다. 본 연구는 선행연구와 사상사에서 다루어진 '가상' 개념에 대한 중요 담론을 검토하여 매개현실의 문제와 한계를 설명하고자 하였다. 매개현실의 가상성은 여론에 영향을 미칠 뿐만 아니라 권력의 사회화, 사회 통제, 사회주도권 개념들과도 쉽게 연결 지을 수 있었다.

• 한국정보시스템학회지:정보시스템연구
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• 제26권2호
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• pp.1-23
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• 2017

Purpose Facebook is a social network service that has the highest number of Monthly Active Users around the world. Hence, marketers have selected Facebook as the most important platform to get customer engagement. With respect to the customer engagement enhancement, the most popular and engaging post type in the Facebook brand fan pages related to what was usually classified as 'sweepstakes'. Sweepstakes refer to a form of gambling where the entire prize may be awarded to the winner. Which makes customers more engaged with the brand. This study aims to explore sweepstakes-oriented social media marketing approaches based on the application of big data analytics. Design/methodology/approach we collect sweepstakes data from each company based on the data crawling from the Facebook brand fan pages. The output of this study explains how companies in each category of FCB grid can design and apply sweepstakes for their social media marketing. Findings The results show that they have one thing in common across the four quadrants of FCB grid. Regardless of the quadrants, most frequently observed type is 'Simple/Quiz or Comments/Quatrains [event type of sweepstakes] + Gifticon [type of reward prize] + Image [type of message display] + No URL [Link toother website] +Single-Gift-Offer [type of reward prize payment]'. So, if the position of the brand is hard to be defined by the FCB grid model, then this general rule can be applied to all types of brands. Also some differences between the quadrants of the FCB grid were observed. This study offers several research implications by analyzing Sweepstakes-oriented social media marketing approaches in Facebook brand fan pages. By using the FCB grid model, this study provides guidance on how companies can design their sweepstakes-oriented social media marketing approaches in the context of Facebook brand fan pages by considering their context.

• 한국인터넷방송통신학회논문지
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• 제18권5호
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• pp.209-214
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• 2018

본 논문에서는 대규모 재난이 발생할 경우 재난으로 인해 시설물에 가해지는 피해를 알아보고 그로 인해 발생 가능한 재난들을 매트릭스 형식으로 나타내었다. 대규모 재난으로 태풍을 선정하였으며 태풍으로 인해 발생 가능한 피해인 홍수피해를 주로 다뤘다. 홍수피해의 경우 주로 침수가 발생하게 되고 침수심과 유속에 따라 피해여부가 결정되게 되며 이를 저층시설물에 적용한 결과를 도출해 내었다. 또한 시설물 피해로 인한 재난 연계를 한눈에 알아보기 쉽도록 매트릭스 형식으로 재난 유형을 분류하는 방법을 적용시켜 결과를 도출시켰다. 본 논문에서 제시한 형식으로 지속적인 연구가 진행되었을 경우 재난 발생에 따른 추가적인 재난을 미리 알아보는데 도움이 될 것이다.