• Advances in Computational Design
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• 제7권4호
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• pp.321-343
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• 2022

Museum buildings display artefacts for public education and enjoyment, ensuring their long-term safety and the comfort of visitors by following strict indoor environment control protocols using mechanical Heating, Ventilation and Air Conditioning (HVAC) systems to keep the (environmental) variables at a fixed comfort level. Maintaining this requires constant supply of energy currently mostly sourced from the combustion of fossil fuels which exacerbates climate change. However, a review on the effects of the indoor environmental variables on museum artefacts as well as museum visitors revealed that there is no specific point at which artefact deterioration occurs, and that there are wide ranges of conditions that guarantee the long-term safety of artefacts and human comfort. Visits to museum buildings in hot-humid tropical climate of Nigeria revealed that strict indoor environmental practices were adopted. Even when appropriate micro-climatic conditions are provided for artefacts, mechanical HVAC systems remain necessary for visitor comfort because almost no consideration is given to natural ventilation. With the current global push towards energy management, this paper reviewed passive environmental control practices, architectural design strategies, and discusses the adaptation of double skin façade with jali screens, and the notion of smart materials, which can satisfy the range of requirements for the long-term safety of artefacts and levels of human comfort in buildings in hot-humid tropical climate, without mechanical HVAC systems. This review would inspire more discussions on passive, energy efficient, smart and climate responsible popular architecture, challenging current thinking on the impact of the more accepted representative architecture.

• 한국가스학회지
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• 제28권1호
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• pp.1-10
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• 2024

본 연구에서는 농업 분야 에너지 자립 시스템 기술도입의 일환으로 농산부산물 기반 SOFC 열병합발전 시스템의 공정 모사 모델을 구축하고 열교환망 최적화를 진행하였다. 0.3 ton/d급 농산부산물 반탄화 연료 가스화기 실험 결과를 기반 농산부산물 SOFC 열병합발전 시스템 모델을 구축하여 4~20 kW급 SOFC 발전 용량별 열교환망 최적화를 진행하였다. 현재 시스템상에서 8 kW급 농산부산물 기반 SOFC 열병합발전 시스템이 최적으로 도출되었으며, 본 연구 결과를 기반으로 추후 상용 설비 설계 시 기초자료로 활용이 가능할 것으로 판단된다.

• Macromolecular Research
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• 제12권6호
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• pp.564-572
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• 2004

Modem applications could benefit from multifunctional materials having anisotropic optical, electrical, thermal, or mechanical properties, especially when coupled with locally controlled distribution of the directional response. Such materials are difficult to engineer by conventional methods, but the electric field-aided technology presented herein is able to locally tailor electroactive composites. Applying an electric field to a polymer in its liquid state allows the orientation of chain- or fiber-like inclusions or phases from what was originally an isotropic material. Such composites can be formed from liquid solutions, melts, or mixtures of pre-polymers and cross-linking agents. Upon curing, a 'created composite' results; it consists of these 'pseudofibers' embedded in a matrix. One can also create oriented composites from embedded spheres, flakes, or fiber-like shapes in a liquid plastic. Orientation of the externally applied electric field defines the orientation of the field-aided self-assembled composites. The strength and duration of exposure of the electric field control the degree of anisotropy created. Results of electromechanical testing of these modified materials, which are relevant to sensing and actuation applications, are presented. The materials' micro/nanostructures were analyzed using microscopy and X-ray diffraction techniques.

• Smart Structures and Systems
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• 제15권6호
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• pp.1503-1520
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• 2015

This paper provides a novel solution for thick-walled cylinders made of functionally graded materials (FGMs). In the formulation, the cylinder is divided into N layers. On the individual layer, the Young's modulus is assumed to be a constant. For an individual layer, two undetermined constants are involved in the elastic solution. Those undetermined coefficients can be evaluated from the continuation condition along interfaces of layers and the boundary conditions at the inner surface and outer surface of cylinder. Finally, the solution for thick-walled cylinders made of functionally graded materials is obtainable. This paper provides several numerical examples which are useful for engineer to design a cylinder made of FGMs.

• Smart Structures and Systems
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• 제19권5호
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• pp.539-551
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• 2017

A mathematical model of electro-thermoelasticity has been constructed in the context of a new consideration of heat conduction with memory-dependent derivative. The governing coupled equations with time-delay and kernel function, which can be chosen freely according to the necessity of applications, are applied to several concrete problems. The exact solutions for all fields are obtained in the Laplace transform domain for each problem. According to the numerical results and its graphs, conclusion about the proposed model has been constructed. The predictions of the theory are discussed and compared with dynamic classical coupled theory. The result provides a motivation to investigate conducting thermoelectric viscoelastic materials as a new class of applicable materials.

• 한국세라믹학회지
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• 제55권4호
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• pp.307-324
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• 2018

Rechargeable lithium-ion batteries (LIBs) have been rapidly expanding from IT based applications to uses in electric vehicles (EVs), smart grids, and energy storage systems (ESSs), all of which require low cost, high energy density and high power density. The increasing demand for LIBs has resulted in increasing price of the lithium source, which is a major obstacle to wider application. To date, the possible depletion of lithium resources has become relevant, giving rise to the interest in Na-ion batteries (NIBs) as promising alternatives to LIBs. A lot of transition metal compounds based on conversion-alloying reaction have been extensively investigated to meet the requirement for the anodes with high energy density and long life-time. In-depth understanding the electrochemical reaction mechanisms for the transition metal compounds makes it promising negative anode for NIBs and provides feasible strategy for low cost and large-scale energy storage system in the near future.

• 디자인학연구
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• 제17권1호
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• pp.49-62
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• 2004

무선인터넷으로 상호작용 하는 정보를 다양한 그래픽으로 가시화하면서 인터페이스를 통일화한 무선인터넷 단말기용 GUI (Graphic User Interface)가 사용자의 선택의 폭을 확장하고 감성만족도 향상에 크게 기여한다는 점에서 매우 고무적인 기술적 진전으로 받아들여지고 있다. 특히 최근 무선인터넷 단말기의 해상도와 색상이 높아지면서 사용상의 편의성과 시각효과를 강조한 GUI를 요구하고 있어 향후 이 분야의 연구가 크게 증가할 것으로 전망된다. 모바일 컴퓨팅의 인터페이스는 사용자들의 미감과 정보효율성에 중요한 영향을 미칠 것이다. 현재 국내 상황은 무선인터넷업체와 GUI 디자인업체가 핸드폰 PDA 스마트폰 등 무선인터넷 단말기를 통일된 사용방법으로 작동하면서 다양한 그래픽 화면을 처리할 수 있게 해주는 GUI개발에 전력하고 있다. 사례연구에서는 Nokia 3650 모델과 MS의 Orange SPV 모델이 제공된다. 이 두 모델의 사용성 비교평가를 통해 PDA와 Phone이 결합된 형식의 차세대 스마트폰 UI 개발에 벤치마킹하고자 한다. 2535세대의 취향에 맞는 유저빌리티 개발을 중심으로 WIPI WAP 메뉴를 구성 하고, WAP서비스 및 VM Browser, PDA Browser개발을 위한 연구 자료로 활용할 수 있으며 사용자의 디자인 선호도 분석을 통해 WAP 메뉴로의 접근성을 감성적으로 강화시키고자 함이 본 연구의 목적이다. 본 연구에서 제시하는 평가모형은 무선인터넷단말기를 개발하는 개발자, 디자이너, 기획자들에게 보다 효과적인 인터페이스 분석 자료를 제공하며, 스마트 폰 개발 시 고려해야 할 Check point 제시를 통해 WIPI 폰의 GUI Guideline으로의 활용을 기대한다.

• 문화기술의 융합
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• 제10권1호
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• pp.525-532
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• 2024

본 연구에서는 스마트팔찌와 스마트워치의 물리적 특성이(예: 모양, 색상, 소재, 크기, 무게, 기술적 기능) 소비자의 기능적, 심미적, 상징적 가치 지각에 미치는 영향을 확장된 기술수용모형을 사용하여 탐색하였다. 스마트팔찌나 스마트워치를 사용한 경험이 있는 미국 거주 성인 남녀를 대상으로 온라인 설문조사를 실시하였고, 최근 1년 사용했거나 현재 사용중인 제품에 대한 다양한 물리적 특성과 그에 대한 평가를 질문하였다. 연구 결과, 전면 디스플레이 모양이 상징적 가치에 유의한 영향을 미쳤는데, 구체적으로 원과 정사각형은 직사각형보다 유의하게 높은 상징적 가치를 보였다. 손목밴드의 소재 역시 상징적 가치에 유의한 영향을 미쳤으며, 여러 소재 중에서도 금속과 가죽의 상징적 가치가 높게 나타났다. 또한, 제품의 크기가 클수록 높아지는 상징적 가치를 확인하였다. 이 외에도 활동 추적, 알람 시계, 거리 추적과 같은 기술적 기능은 기능적 가치를, 시계, GPS, 이메일 같은 기술적 기능은 심미적 가치를, 보폭계, GPS, 이메일은 상징적 가치를 높게 지각하도록 했다. 이러한 결과는 스마트팔찌와 스마트워치에 대한 소비자 욕구를 이해하여 제품을 개선하거나 신제품 개발하는 자료로 사용될 수 있다.

• 한국세라믹학회지
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• 제52권1호
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• pp.23-27
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• 2015

Recently, the use of ion-exchange strengthened glass has increased sharply, as it is now used as the cover glass for smart phone devices. Therefore, many researchers are focusing on methods that can be used to strengthen ion-exchange glass. However, research on how the improved strength can be maintained under thermal environment of device manufacturing is still insufficient. We tested the degradation of the characteristics of ion-exchange soda-lime glass samples, including their surface compressive stress characteristics, the depth of the ion-exchange layer (DOL), flexural strength, hardness, and modulus of rupture (MOR) values. Degradation of the characteristics of the ion-exchange glass samples occurred when they were heat-treated at a temperature that exceeded $350^{\circ}C$.

• International journal of advanced smart convergence
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• 제7권4호
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• pp.84-91
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• 2018

In this paper, we simulated three different HV systems and analyzed of each vacuum characteristics by VacCAD modelling. In each of modelled vacuum systems, selection of chamber materials, combination of rough pump with high vacuum pump and conductance of roughing line (diameter and length) were proposed as system variables. In the modelling of chamber materials, the pumping times to ultimate pressures of different chamber materials (stainless steel, aluminum) were compared by the variations of chamber volume. In this model, the effects of outgassing dependent on the chamber materials was also simulated and aluminum was estimated to optimum chamber materials. It was also obtained that modelling of vane and roots pump with diffusion pump and diameter, length of $50{\times}250$ [mm]roughing line were characterized as optimum variables to reach the ultimate pressure of 10E-7 [mbar] most effectively. Optimum design factors for vacuum characteristics of modelled vacuum system were achieved by VacCAD simulations. Feasibility of VacCAD as vacuum simulator was verified and applications of VacCAD expected to be increased to fields in vacuum needed.