• 한국세라믹학회지
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• 제45권7호
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• pp.411-417
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• 2008

Aerosol Deposition Method (ADM) is a novel technique to grow ceramic thick films with high density and nano-crystal structure at room temperature. $^{1,2)}$ For these unique advantages of ADM, it would be applied to the fabrication process of 3-D integration ceramic modules effectively. However, it is critical to control the properties of starting powders, because a film formation through ADM is achieved by impaction and consolidation of starting powders on the substrates. We fabricated alumina thick films by ADM for the application to integral substrates for RF modules. When the as-received alumina powders were used as a starting material without any treatments, it was observed that the dielectric properties of as-deposited alumina films, such as relative permittivity and loss tangent, showed high dependency on the frequency. In this study, some techniques of powder pre-treatments to improve the dielectric properties of alumina thick films will be shown and the effects of starting powders on the properties of AD films will be discussed.

• 한국전기전자재료학회논문지
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• 제33권2호
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• pp.88-92
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• 2020

Thermal effects in bulk and SOI FinFETs are briefly reviewed herein. Different techniques to measure these thermal effects are studied in detail. Self-heating effects show a strong dependency on geometrical parameters of the device, thereby affecting the reliability and performance of FinFETs. Mobility degradation leads to 7% higher current in bulk FinFETs than in SOI FinFETs. The lower thermal conductivity of SiO₂ and higher current densities due to a reduction in device dimensions are the potential reasons behind this degradation. A comparison of both bulk and SOI FinFETs shows that the thermal effects are more dominant in bulk FinFETs as they dissipate more heat because of their lower lattice temperature. However, these thermal effects can be minimized by integrating 2D materials along with high thermal conductive dielectrics into the FinFET device structure.

• Earthquakes and Structures
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• 제4권5호
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• pp.451-470
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• 2013

It generally accepted that most building structures shall exhibit a nonlinear response when subjected to medium-high intensity earthquakes. It is currently known, however, that this phenomenon is not properly modelled in the majority of cases, especially at the design stage, where only simple linear methods have effectively been used. Recently, as a result of the exponential progress of computational tools, nonlinear modelling and analysis have gradually been brought to a more promising level. A wide range of modelling alternatives developed over the years is hence at the designer's disposal for the seismic design and assessment of engineering structures. The objective of the study presented herein is to test some of these models in an existing structure, and observe their performance in nonlinear static and dynamic analyses. This evaluation is done by the use of two of a known range of advanced computer programs: SAP2000 and SeismoStruct. The different models will focus on the element flexural mechanism with both lumped and distributed plasticity element models. In order to appraise the reliability and feasibility of each alternative, the programs capabilities and the amount of labour and time required for modelling and performing the analyses are also discussed. The results obtained show the difficulties that may be met, not only in performing nonlinear analyses, but also on their dependency on both the chosen nonlinear structural models and the adopted computer programs. It is then suggested that these procedures should only be used by experienced designers, provided that they are aware of these difficulties and with a critical stance towards the result of the analyses.

• 한국유기농업학회지
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• 제20권3호
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• pp.267-282
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• 2012

In this study, RPS system, one of the renewable energy support systems, is utilized for economic analysis of solar generation equipment and the fuel cost savings plan for controlled horticulture farms with high fuel-cost dependency and facility applicability were evaluated. On the exterior of the upper layer of glass greenhouse (9917$m^2$) of controlled horticulture farms using bunker C oil, half of the area (4958$m^2$) was utilized for theoretical installation and operation of 450kW-level solar power generator, and as the result, first, the effect of investment cost only of solar generation system was found to be quite excellent, but it was analyzed that there were limits to saving the fuel costs of the controlled horticulture farms. Second, when geothermal system was first introduced in the farm and solar system was additionally introduced, it was analyzed that the effect of introducing solar system was excellent. In order to apply such effects to the sites of farming, partial supplementation of RPS system which is being uniformly applied regardless of the purpose of renewable energy is necessary. When the subject of use directly install facilities where it is directly connected to national added-value such as food security created by the farming industry, it is necessary to introduce appropriate system that corresponds to such. Moreover, it was studied that the quick development of demonstrative complex that can practically evaluate the applicability of renewable energy in farming industry and interest and preparation of related institutions in financial support structure for its site application would lead to success.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.21-21
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• 2011

A series of Quasi-Elastic Neutron Scattering (QENS) experiments helps us to understand the single-particle (hydrogen atom) dynamics of a globular protein and its hydration water and strong coupling between them. We also performed Molecular Dynamics (MD) simulations on a realistic model of the hydrated hen-egg Lysozyme powder having two proteins in the periodic box. We found the existence of a Fragile-to-Strong dynamic Crossover (FSC) phenomenon in hydration water around a protein occurring at TL=$225{\pm}5K$ by analyzing Intermediate Scattering Function (ISF). On lowering of the temperature toward FSC, the structure of hydration water makes a transition from predominantly the High Density Liquid (HDL) form, a more fluid state, to predominantly the Low Density Liquid (LDL) form, a less fluid state, derived from the existence of a liquid?liquid critical point at an elevated pressure. We showed experimentally and confirmed theoretically that this sudden switch in the mobility of the hydration water around a protein triggers the dynamic transition (so-called glass transition) of the protein, at a temperature TD=220 K. Mean Square Displacement (MSD) is the important factor to show that the FSC is the key to the strong coupling between a protein and its hydration water by suggesting TL${\fallingdotseq}$TD. MD simulations with TIP4P force field for water were performed to understand hydration level dependency of the FSC temperature. We added water molecules to increase hydration level of the protein hydration water, from 0.30, 0.45, 0.60 and 1.00 (1.00 is the bulk water). These confirm the existence of the FSC and the hydration level dependence of the FSC temperature: FSC temperature is decreased upon increasing hydration level. We compared the hydration water around Lysozyme, B-DNA and RNA. Similarity among those suggests that the FSC and this coupling be universal for globular proteins, biopolymers.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제10권2호
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• pp.156-173
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• 2004

협업 워크플로우 관점에서 비즈니스 프로세스는 기업 내외의 애플리케이션들과 인적 자원들과의 유기적인 결합을 통하여 협업 프로세스를 신속하고 유연하게 수행할 수 있도록 지원하여야 한다. 현재기업 업무에 대한 시스템 의존도가 높아지고는 있지만, 인간은 여전히 핵심적인 역할을 차지한다. 즉 워크플로우 모델링에는 이러한 인간의 역할이 강조되어야 하며 인간 의사결정 과정 자체를 분석하여 인적오류를 제어할 수 있는 구조가 반드시 필요하다. 또한 액티비티간의 협업을 통하여 빠르고 효율적인 커뮤니케이션이 구축되어 궁극적으로는 액티비티들이 목표 프로세스에 연류되어 결과물에 대한 품질이 향상되도록 하여야 한다. 이에 본 논문에서는 협업 워크플로우에서 발생할 수 있는 인적오류를 제어하기 위해 GEMS(Generic Error Modeling System) 모델을 적용한다. 또한 하이브리드 기반의 모델링 방법을 통한 인적오류 제어 방법을 제시한다. 아울러 이러한 기반에서 협업 워크플로우를 모델링할 수 있는 도구를 설계하고 구현한다. 이와 같은 모델링 방법을 사용하면 인간 자체의 특성을 고려함으로써 인적오류를 제어할 수 있는 워크플로우 모델링이 될 수 있도록 지원할 수 있다.

• 과학기술학연구
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• 제8권1호
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• pp.1-28
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• 2008

이 글에서는 새롭게 등장하고 있는 사회적 목표를 지향하는 혁신정책의 특성들을 살펴보고 그것이 우리의 혁신정책에 주는 함의를 살펴보았다. 우선 이 정책들은 지속가능성과 같은 목표를 제시하고 그것에 경제성장보다 앞서는 우선권을 부여하고 있다. 또 이 정책들은 개별적인 기술개발이나 국지적인 문제해결을 넘어 사회 기술시스템 전체의 전환(system transition)을 염두에 두고 있다. 그리고 시스템 전환을 위해, 새로운 내용을 갖는 기술과 사회제도를 실험하여 기술적 지식을 확충하고 정당성을 향상시키는 '전략적 니치 관리' 방식을 채택하고 있다. 장기적이고 근본적인 변화 방향과 구체적이고 국지적인 정책과 사업들을 학습 과정을 통해 연계시키고 있는 것이다. 이와 함께 정책들의 기획 및 집행과정에서 공공적 참여자의 역할을 확대하고 있다. 이런 정책이 우리에게 주는 함의는 2007년에 발표된 "기술기반 삶의 질 향상 종합대책"을 중심으로 논의하였다. 이 대책은 경제성장 중심 혁신정책의 틀을 넘어서는 새로운 정책이었지만 기존 정책들의 관성으로 인해 몇 가지 한계가 있음을 지적하였다. 특히 과거 산업화 과정에서 형성된 타겟팅적 경향 때문에 장기적 관점에서 시스템 전환을 고려하는 관점이 도입되는 데 어려움이 있다는 것을 논의하였다.

• 대한간호학회지
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• 제49권6호
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• pp.724-735
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• 2019

Purpose: This study was conducted to investigate relationship between delirium, risk factors on delirium, and patient prognosis based on Donabedian's structure-process-outcome model. Methods: This study utilized a path analysis design. We extracted data from the electronic medical records containing delirium screening data. Each five hundred data in a delirium and a non-delirium group were randomly selected from electronic medical records of medical and surgical intensive care patients. Data were analyzed using SPSS 20 and AMOS 24. Results: In the final model, admission via emergency department (Β=.06, p=.019), age over 65 years (Β=.11, p=.001), unconsciousness (Β=.18, p=.001), dependent activities (Β=.12, p=.001), abnormal vital signs (Β=.12, p=.001), pressure ulcer risk (Β=.12, p=.001), enteral nutrition (Β=.12, p=.001), and use of restraint (Β=.30, p=.001) directly affecting delirium accounted for 56.0% of delirium cases. Delirium had a direct effect on hospital mortality (Β=.06, p=.038), hospital length of stay (Β=5.06, p=.010), and discharge to another facility (not home) (Β=.12, p=.001), also risk factors on delirium indirectly affected patient prognosis through delirium. Conclusion: The use of interventions to reduce delirium may improve patient prognosis. To improve the dependency activities and risk of pressure ulcers that directly affect delirium, early ambulation is encouraged, and treatment and nursing interventions to remove the ventilator and drainage tube quickly must be provided to minimize the application of restraint. Further, delirium can be prevented and patient prognosis improved through continuous intervention to stimulate cognitive awareness and monitoring of the onset of delirium. This study also discussed the effects of delirium intervention on the prognosis of patients with delirium and future research in this area.

• 한국지진공학회논문집
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• 제9권2호통권42호
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• pp.47-58
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• 2005

이산폰툰형 부유식교량의 시간영역 지진응답해석을 지진파의 공간분포를 고려하여 수행하였다. 지반운동의 공간변화는 파의 통과 영향, 엇결성 뎡향 및 국부지반 영향을 반영하는 결맞음 함수 모델로 고려하였다. 부유식 교량의 상부구조는 공간뼈대요소와 탄성현수케이블요소를 이용하여 모델링 하였고, FHWA 가이드라인의 스프링 모델을 사용하여 교대의 지반 구조물 상호작용에 대한 영향을 고려하엿으며, 경계요소법으로 산정한 폰툰 동수력계수의 주파수 의종성을 고려하기 위해서 시간지연함수를 사용하였다. 지반운동의 공간변화를 고려한 다중지점 지진입력을 교량의 양단에 도입하였고 응답의 시간이력을 동시 가진 시와 비교하였다. 장주기의 동적특성을 갖는 이산폰툰형 부유식 교량의 지진응답 해석에서 지반운동의 공간분포를 고려할 경우에 주몰할만한 응답의 증폭이 나타날 수 있음을 확인하였다.

• 한국세라믹학회지
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• 제38권12호
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• pp.1093-1096
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• 2001

ZnO내 $Al_2$ $O_3$의 고용은 $Al^{3+}$ 의 ZnO 결정의 $Zn^{2+}$자리, 즉 wurtizite 구조에서 4개의 산소가 만드는 4면체 공간자리로서 치환반응으로 정의될 수 있다. 이 반응은 아연-빈자리 혹은 산소-빈자리와 연관되어 일어나므로 ZnO의 비화학량론성 및 결정결함반응들과 상관관계를 가진다. 이러한 상호연관성은 아연-빈자리 및 산소분압(P $o_2$) 의존성을 낳으며, 결과적으로 ZnO내 Al 용해도([Al/sug zn/]$_{max}$)의 산소분압 의존성을 야기한다. 본 논문은 ZnO내에 Al의 용해도는 산소분압이 증가하면 감소한다는 것을 처음으로 곗나하여 보고한다. [A $l_{zn}$ ]$_{max}$ $P_{o2}$$^{-1}$4/./.