• Smart Structures and Systems
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• 제13권4호
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• pp.615-636
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• 2014

Aluminium Foam Sandwich (AFS) panels are becoming always more attractive in transportation applications thanks to the excellent combination of mechanical properties, high strength and stiffness, with functional ones, thermo-acoustic isolation and vibration damping. These properties strongly depend on the density of the foam, the morphology of the pores, the type (open or closed cells) and the size of the gas bubbles enclosed in the solid material. In this paper, the vibrational performances of two classes of sandwich panels with an Alulight(R) foam core are studied. Experimental tests, in terms of frequency response function and modal analysis, are performed in order to investigate the effect of different percentage of porosity in the foam, as well as the effect of the random distribution of the gas bubbles. Experimental results are used as a reference for developing numerical models using finite element approach. Firstly, a sensitivity analysis is performed in order to obtain a limit-but-bounded dynamic response, modelling the foam core as a homogeneous one. The experimental-numerical correlation is evaluated in terms of natural frequencies and mode shapes. Afterwards, an update of the previous numerical model is presented, in which the core is not longer modelled as homogeneous. Mass and stiffness are randomly distributed in the core volume, exploring the space of the eigenvectors.

• 인간식물환경학회지
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• 제24권1호
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• pp.1-16
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• 2021

Background and objective: People-nature experiences, which suggest that humans seek connections between nature and other forms of life, were presented by biologist E. O. Wilson in 1984. Biophilic design attributes support environments that can improve human connections to nature. A significant amount of literature on environmental psychology provides empirical evidence that nature benefits humans, and that practical landscape and built environments can be designed to link humans and nature (e.g., the 14 biophilic design patterns). To date, however, there has been no well-done research on reviewing the health benefits of biophilic design. Methods: The paper provides a narrative review on biophilic design and human health. The scope of this article is limited to biophilic-design books and peer-review articles related to "biophilic design," "evidence-based," "benefits," "health," rather than an attempt to identify universal issues with biophilia hypothesis. Results: A total of 45 papers were included in our review, which was related to the top five biophilic design patterns and design: the presence of natural images, the presence of plants, visual and non-visual connections to nature, and material connection with nature. These studies were related to physiology and psychology through direct or indirect connections with nature and experiences in space and place. Conclusion: This study presents two important comparisons of the empirical research on biophilic design and human health that can explain the relationship of people-nature experiences to biophilic design and human health and provides insights into related researches and recommendations for future application of our findings.

• 한국환경생태학회지
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• 제36권5호
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• pp.525-534
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• 2022

본 연구에서는 실제와 가상의 자연 그대로의 숲과 인위적으로 통제가 가능한 VR을 활용한 가상 숲에서의 체험이 성인의 심리적 또는 생리적으로 미치는 효과를 알아보기 위해 수행되었다. 실험은 자연 숲 환경과 외부 빛이 차단된 대학원세미나실에서 진행되었으며, 피험자는 성인 대학생 60명이 참가하였다. 실험은 심리적, 생리적 회복을 통해 자연 숲 환경과 VR 숲 환경에서의 효과를 비교 후 상태를 평가하였다. 심리적 측정 결과 피험자들은 자연 숲 환경과 VR 숲 환경에서 산림 경관을 체험 후에 PANAS를 통한 심리지수에서 긍정적 정서가 증가하고 부정적 정서가 감소되었음을 확인하였고, 타액을 이용한 스트레스 지수인 코티졸을 측정한 결과 두 그룹에서 스트레스 지수가 유의하게 감소되었음을 확인하였다. 거리상 이동의 제약 또는 거동이 불편 등 제약으로 인하여 자연 숲 환경에서 체험을 못하는 사람들에게 VR 숲 환경에서 심리적, 생리적으로 회복 환경을 만들어주는데 사용할 수 있을 것이다. 이러한 연구의 결과가 산림 치유의 시각적 효과에 대한 기반이 되길 기대하고, 산림분야에서 4차 산업의 기술인 VR의 환용이 넓어지는 기반이 되길 기대한다.

• 한국초등과학교육학회지:초등과학교육
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• 제17권1호
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• pp.89-103
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• 1998

We study that what kind of the concepts of evaporation and condensation students of elementary school have. The results are following. (1) The students have simple concepts of evaporation on natural circumstance. However, they don't understand about various effect on evaporation. (2) They don't know where the evaporized water is comming from. (3) They have experiences on observing condensation of wale. (70%), however don't know that the water is evaporized in the air. (4) They have more understanding about evaporation, more correct concepts on condensation in circulation of water.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제5B권2호
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• pp.142-145
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• 2005

The life expectancy of a transformer largely depends on the temperature-rise it experiences. If the temperature-rise exceeds limits specified in the design standards, the aging of insulating materials is accelerated and the capability of the cooling medium is deteriorated. Consequently, applicable limits for the temperature-rise are essential in designing the transformer and the coolers, demanding the estimation of the transformer's thermal behavior. In order to analyze the temperature characteristics of the transformer, numerical analysis by way of the commercial CFD code has been carried out, and temperature-rise testing to verify computed results was performed. The results obtained in this study show that there is a good agreement between computed outcomes and experimental outcomes.

• 전기학회논문지
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• 제67권7호
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• pp.954-961
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• 2018

In this paper, a chatbot for emotional stress recognition and management using rule-based method and NLP is designed and developed to tackle various emotional stresses of people through questionnaire. For this, Dialogflow as open chatbot development platform and Facebook messenger as chatting platform are used. We can build natural and resourceful conversational experiences through predefined questions by using powerful tools of Dialogflow, and can use developed chatbot on the Facebook page messenger. Developed chatbot perceives emotional stresses of user by user-input which is either text or choice of predefined answer. It also gives user questions according to the user's feeling, and assess the strength of the emotional stresses, and provide a solution to the user. Further research can improve the developed chatbot by using open Korean NLP library and database of emotions and stresses.

• Ocean Systems Engineering
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• 제7권1호
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• pp.53-74
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• 2017

Ship shaped FPSO (Floating Production, Storage and Offloading) units are the most commonly used floating production units to extract hydrocarbons from reservoirs under the seabed. These structures are usually much larger than general cargo ships and have their natural frequency outside the wave frequency range. This results in the response to first order wave forces acting on the hull to be negligible. However, second order difference frequency forces start to significantly impact the motions of the structure. When the difference frequency between wave components matches the roll natural frequency, the structure experiences a significant roll motion which is also termed as second order roll. This paper describes the theory and numerical implementation behind the calculation of second order forces and motions of any general floating structure subjected to waves. The numerical implementation is validated in zero speed case against the commercial code OrcaFlex. The paper also describes in detail the popular approximations used to simplify the computation of second order forces and provides a discussion on the limitations of each approximation.

• Educational Technology International
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• 제18권1호
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• pp.49-71
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• 2017

The purpose of the study was to identify key design features of virtual reality with head-mounted displays (HMD) and touchless interface for the hearing-impaired and hard-of-hearing learners. The virtual reality based training program was aimed to help hearing-impaired learners in machine operating learning, which requires spatial understanding to operate. We developed an immersive virtual learning environment prototype with an HMD (Oculus Rift) and a touchless natural user interface (Leap Motion) to identify the key design features required to enhance virtual reality for the hearing-impaired and hard-of-hearing learners. Two usability tests of the prototype were conducted, which revealed that several features in the system need revision and that the technology presents an enormous potential to help hearing-impaired learners by providing realistic and immersive learning experiences. After the usability tests of hearing-impaired students' exploring the 3D virtual space, interviews were conducted, which also established that further revision of the system is needed, which would take into account the learners' physical as well as cognitive characteristics.

• 한국산림휴양학회지
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• 제22권4호
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• pp.83-94
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• 2018

본 연구는 자연공원분야에 서비스스케이프의 개념을 적용하여 서비스스케이프가 탐방객의 지각된 가치, 전반적 만족 그리고 행동의도에 미치는 영향을 살펴보고자 하였다. 연구결과, 자연공원의 서비스스케이프는 주차장, 화장실, 휴식공간, 부대시설 등 공원 내의 시설을 중심으로, 공원까지의 접근성과 시설이용의 편리성 및 쾌적성의 3개 요인으로 측정할 수 있었다. 또한 탐방객들이 공원 내의 시설 즉, 서비스스케이프를 호의적으로 인지하면 무형적인 경험의 가치도 호의적으로 인식하게 되어 결과적으로 전반적인 만족과 행동의도에 긍정적으로 작용하는 것으로 확인되었다. 특히 탐방객들은 탐방경험을 통한 시간가치를 중요하게 인식하였으며, 이에는 서비스스케이프 요인 중 쾌적성이 영향을 미치는 것으로 나타나 자연공원의 관리적 측면에서 청결하고 쾌적한 환경조성을 위한 지속적인 노력의 중요성을 시사하였다. 본 연구는 자연공원에 서비스스케이프의 개념을 적용한 첫 번째 사례라는 점에서 의의를 지니며, 후속연구를 통해 연구결과의 일반화와 신뢰성의 향상이 요구된다.

• 한국실내디자인학회논문집
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• 제6호
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• pp.38-44
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• 1995

The purpose of this paper is to show that a shape pro-duced by natural factors such as weather, environments, etc., can be introduced into the emotion of a design, and to make a design process by planning a Korean image and characterizing its concept. Human beings, nature, man-made objects, and society have their own functions in an environmental structure. When all their functions are kept in working order, human beings come to discover orderliness out of which they can absorb pleasure. They cannot look into their own inside but they can trace back in their memories a variety of panoramic experiences which have been embed-ded onto their identity during their lifetime interactions with an empirical world. Children first acquire a way of cognition in the space, a comprehensive premise, connecting a specific place and an object of cognition. Such subconsciousness forms sky-lines of mountains, seas, and trees under the sky, and produces axis lines and beehived domes under the influ-ence of natural, cultural, and social factors, forming a folk culture. A subconscious composition of existential space is extended. A subconscious composition of existential space is extended to the areas of environmental design, product design, and fashion design. The development of a concept of place and space as a system is a necessary condition for discovering an existential foothold.