• 제목/요약/키워드: Multi-functional groups

검색결과 77건 처리시간 0.026초

탄소나노튜브의 열처리에 따른 고분자전해질연료전지용 촉매의 표면처리 및 담지특성 향상 (Improvement of Catalyst Supporting Characteristic on MWCNTs with Different Thermal Treatment for PEMFC)

  • 권민기;정주해;김준범
    • 전기화학회지
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    • 제14권4호
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    • pp.245-252
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    • 2011
  • 본 연구에서는 탄소나노튜브를 담지체로 사용하여 연료전지용 백금(Pt) 촉매의 고분산, 고담지를 목적으로 하였다. 탄소나노튜브의 표면처리는 열적산화방식으로 전처리하였다. 25, 50, 90 및 $110^{\circ}C$에서 열처리를 하였을 경우, 온도변화에 따른 작용기의 영향을 FT-IR, XPS를 통해 분석하였다. XPS를 통해 전처리의 온도가 증가할수록 작용기의 농도가 증가하는 것을 확인 하였으며, TGA와 TEM을 통해 Pt의 담지량과 분산도 또한 증가한 것을 확인하였다. 산화과정에서 열적거동은 고담지 Pt 촉매의 제조와 밀접한 관련이 있으며, 본 연구에서 제조된 촉매의 고분산, 고담지에 적절한 합성 온도는 $90^{\circ}C$로 관찰되었으며 단위전지에서 가장 좋은 성능을 나타내었다.

한국 심혈관질환 특이형 삶의 질 측정도구 개발 및 평가 (Development and a Psychometric Evaluation of Cardiovascular Disease-Specific Quality of Life Scale for Koreans)

  • 이은현;탁승제;신준한;이영휘;송라윤
    • 대한간호학회지
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    • 제37권3호
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    • pp.313-323
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    • 2007
  • Purpose: Health-related quality of life (HRQOL) in patients with cardiovascular disease in Korea has rarely been studied, mostly due to the lack of a psychometrically validated disease-specific instrument. The purpose of this study was to develop and validate a cardiovascular specific-HRQOL questionnaire (CD-QOL). Method: The CD-QOL was developed and validated as follows; item generation, pilot study, and psychometric tests. Patients were recruited from three-university hospitals. The patients were asked to complete the preliminary questionnaire comprising the content-validated items, SF-36, and CES-D. The NYHA and KASI classifications were used to classify the functional performance of the patients. The data was analyzed using correlation, factor analysis, multidimensional scaling, multitrait/multi-item matrix, ANOVA, and Cronbach's alpha. Result: Preliminarily, thirty-nine items were generated. Factor analysisextracted a five-factor solution with a total of twenty-two items. One item was deleted based upon the MDS. The remaining items were moderately correlated with the subscales of the SF-36 and associated with depression measured with the CES-D. The mean scores of patients in NYHA and KASI class I were significantly higher than those in NYHA and KASI class II or/and III, which suggested patients with better functional performance were likely to have a better HRQOL. Cronbach's alphas of the total and subscales were all greater than 0.70. Conclusion: The CD-QOL is a easily applicable instrument with excellent psychometric properties of content, criterion, factorial, convergent, and known-groups validity, and internal consistency reliability in Korean patients with cardiovascular disease.

현대 소비자의 제품소비경험: 스마트폰 상표 간 비교를 중심으로 (Contemporary Consumers' Product Consumption Experiences: A Comparison between the Two Leading Brands of Smart Phone)

  • 오지은;김기옥
    • 대한가정학회지
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    • 제50권1호
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    • pp.141-154
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    • 2012
  • The purpose of this study was to examine consumers' product experiences from the time when the consumer purchases a smart phone, through to the period of use, and to evaluate the product after a period of usage by comparing two groups of smart phone users of the two leading brands, Galaxy S and iPhone 4G. Product experiences were considered through the process of a consumer purchasing and using a product throughout the whole cycle of product consumption. Product experiences were compared between the two brand users according to their demographic backgrounds. The results indicated that iPhone 4G users were more likely to experience functional superiorities and emotional varieties than Galaxy S users. Especially, iPhone 4G users were more likely to experience enjoyment, aesthetics, enhanced self-images and good relationships with others through the smart phone than the Galaxy S users. Galaxy S users were more likely to identify a corporate's image as a superior feature, while iPhone 4G users were more likely to identify multi-functions and endless applications. This study implies that not only the product's functional superiorities but also the consumers' entire cycle of product experiences should be carefully examined and reflected in the development of successful new products in this competitive market.

알코올 중독에서의 도파민 수용체 유전자 다형성 (Polymorphisms of the Dopamine Receptor Genes in Alcoholism)

  • 유승호
    • 생물정신의학
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    • 제9권1호
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    • pp.15-24
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    • 2002
  • Even though alcoholism is a multi-factorial psychiatric disorder, it is reasonable to suppose that genetic factors play a substantial role in the manifestation of this disorder. Because alcohol is the reinforcing substance which manifests its effects through activation of the mesolimbic dopaminergic reward pathway of the brain, the gene encoding dopamine receptor subtypes can be a major natural candidate gene. Since 1990, many association studies have identified strong evidence implicating the dopamine D2 receptor(DRD2) gene in alcoholism, specifically TaqI A minor(A1) allele. Association studies have also been conducted on other dopamine receptor(DRD3 & DRD4) polymorphisms but the results have yet to be confirmed. Through a number of other approaches, each dopamine receptor gene has been investigated in association with different phenotypes in alcoholism, but further researches will be needed. In conclusion, studies in the past decade have shown that the TaqI A1 allele of the DRD2 gene is associated with alcoholism in various subject groups. Other dopamine receptor genes have since been added to the list but yet to be identified. Thus, the knowledge of these genes and their functional significance will enhance the understanding of the underlying biological mechanisms of alcoholism. Furthermore, it could lead to more helpful prevention and treatment approaches to alcoholism.

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실리콘-화합물 융합 반도체 소자 기술동향 (Technical Trend of Fusion Semiconductor Devices Composed of Silicon and Compound Materials)

  • 이상흥;장성재;임종원;백용순
    • 전자통신동향분석
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    • 제32권6호
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    • pp.8-16
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    • 2017
  • In this paper, we review studies attempting to triumph over the limitation of Si-based semiconductor technologies through a heterogeneous integration of high mobility compound semiconductors on a Si substrate, and the co-integration of electronic and/or optical devices. Many studies have been conducted on the heterogeneous integration of various materials to overcome the Si semiconductor performance and obtain multi-purpose functional devices. On the other hand, many research groups have invented device fusion technologies of electrical and optical devices on a Si substrate. They have co-integrated Si-based CMOS and InGaAs-based optical devices, and Ge-based electrical and optical devices. In addition, chip and wafer bonding techniques through TSV and TOV have been introduced for the co-integration of electrical and optical devices. Such intensive studies will continue to overcome the device-scaling limitation and short-channel effects of a MOS transistor that Si devices have faced using a heterogeneous integration of Si and a high mobility compound semiconductor on the same chip and/or wafer.

도시환경의 이미지 및 시각적 선호도에 관한 연구 -도시 업무용 건물의 외부공간을 중심으로- (The Image and Visual Preference for Urban Setting : Focused on Outdoor Spaces of Urban Office Buildings)

  • 이선화;김유일;서주환
    • 한국조경학회지
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    • 제26권3호
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    • pp.134-142
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    • 1998
  • THe purpose of this study is to suggest the major determinants of visual preference in the outdoor spaces of urban office buildings. For this, the spatial image was analyzed by the factor analysis algorithm. The level of visual preferences was measured by a slide simulation test, and these data were analyzed by the multiple regressioni. The result of this study can be summarized as follows; Factors covering the spatial image were found to be 'mystery','changeability','coherence' and 'legibility'. T.V. was obtained as 58.4%. Outdoor spaces of urban office buildings were classified into four groups by the multi dimensional scaling method. As for the analysis of imageability in each spatial type, the factor scores of measuring high values were different for all types. Type II, IV obtained higher rank of visual preference and type III, I obtained lower. For all types, the factors of visual preference were found to be 'mystery','changeability','coherence' and 'legibility'. The visual preference determinants of urban setting focused on outdoor spaces of urban office buildings may be the major factors which must be considered in planning and designing as the functional basis for the quantitative analysis.

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Self-Organized Grafting of Carbon Nanotubes by End-Functionalized Polymers

  • Lee, Sun-Hwa;Park, Ji-Sun;Koo, Chong-Min;Lim, Bo-Kyung;Kim, Sang-Ouk
    • Macromolecular Research
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    • 제16권3호
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    • pp.261-266
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    • 2008
  • A variety of end-functionalized polymers were grafted spontaneously onto multi-walled carbon nano-tubes (MWNTs) using a solution mixing process. The end-functional groups of the polymers underwent noncovalent grafting to the defect sites at the surface of the purified MWNTs through zwitterionic interaction or hydrogen bonding. The physically grafted polymers including polystyrene (PS), poly(methyl methacrylate) (PMMA), polyethylene oxide (PEO), and polydimethylsiloxane (PDMS) provided sufficient compatibility with an organic solvent or polymer matrix, such that the nanotubes could be finely dispersed in various organic media. This approach is universally applicable to a broad range of polymer-solvent pairs, ensuring highly dispersed carbon nanotubes through simple solution mixing.

Implementation of Falling Accident Monitoring and Prediction System using Real-time Integrated Sensing Data

  • Bonghyun Kim
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제17권11호
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    • pp.2987-3002
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    • 2023
  • In 2015, the number of senior citizens aged 65 and over in Korea was 6,662,400, accounting for 13.1% of the total population. Along with these social phenomena, risk information related to the elderly is increasing every year. In particular, a fall accident caused by a fall can cause serious injury to an elderly person, so special attention is required. Therefore, in this paper, we implemented a system that monitors fall accidents and informs them in real time to minimize damage caused by falls. To this end, beacon-based indoor location positioning was performed and biometric information based on an integrated module was collected using various sensors. In other words, a multi-functional sensor integration module was designed based on Arduino to collect and monitor user's temperature, heart rate, and motion data in real time. Finally, through the analysis and prediction of measurement signals from the integrated module, damage from fall accidents can be reduced and rapid emergency treatment is possible. Through this, it is possible to reduce the damage caused by a fall accident, and rapid emergency treatment will be possible. In addition, it is expected to lead a new paradigm of safety systems through expansion and application to socially vulnerable groups.

공감각 제품디자인의 미각적 요소와 제품과의 적합성이 제품평가에 미치는 영향 : fMRI를 중심으로 (The effect of the appropriateness of gustatory features in 'multi-sensory' product design on product evaluation : An fMRI study)

  • 성영신;최민조
    • 감성과학
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    • 제14권2호
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    • pp.235-244
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    • 2011
  • 본 연구에서는 fMRI 기법을 활용하여 제품과 공감각적 은유가 적용된 제품 디자인에 표현된 미각적 요소와의 적합성 수준이 제품에 대한 신경학적 반응과 제품평가에 미치는 영향에 대하여 알아보고자 하였다. 사전조사를 통해 미각적 요소와 제품 간의 적합성 정도에 따라 제품디자인을 두 그룹으로 나누었다. 총 40개의 제품디자인이 실험자극물로 사용되었다. 총 15명의 건강한 오른손잡이 대학생들이 실험에 참가하였다. 실험은 총 2세션으로 구성되어 있고, fMRI scanning session에서 참가자들은 제품디자인을 관찰하였고, post-scanning session에는 제품디자인에 대한 선호도와 구매의도를 측정하였다. 실험결과 적합성이 높은 제품디자인이 낮은 제품디자인보다 선호도, 구매의도 모두 높게 나타났다. 뇌 반응의 경우 긍정적 보상과 관련된 미상핵(Caudate nucleus)과 피각(putamen) 영역이 적합성이 높은 조건의 제품디자인에서 더 많이 활성화 되는 것으로 나타났다.

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장기요양시설 거주노인의 치매 여부에 따른 신체활동수준과 관련 요인: 개인 및 기관 특성의 영향 (Current Status and Factors Related to Physical Activity of Older Nursing Home Residents with and without Dementia: Effects of Individual and Institutional Characteristics)

  • 전승연;김홍수
    • 보건행정학회지
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    • 제28권4호
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    • pp.392-401
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    • 2018
  • Background: Physical activity (PA) is critical for maintaining the health and well-being of older people in community and also institutional settings. The purpose of this study was to examine the current status of PA and related individual and organizational factors among older nursing home residents with and without dementia. Methods: This is a secondary data analysis study of a nationwide survey of 92 long-term care facilities in Korea, and the study sample includes older residents with dementia (n= 753) and without dementia (n= 480). The level of PA was measured by PA time and whether or not residents had an outdoor activity over the past 3 days. Multi-variate, multi-level analyses were conducted. Results: More than half of the sample in both groups had no or less than 1 hour of PA. About one out of four older people in our sample had no outdoor activity over the past 3 days regardless of whether or not they had dementia. Among the people without dementia, several individual-level factors were associated with PA, including dependency for activities of daily living, social activity participation, and caregivers' belief in the functional improvement of residents. Unlike the non-dementia group, individual- and organizationallevel factors including staffing level and having the relevant equipment for PA were associated with PA among those with dementia. Conclusion: Study findings provide evidence on the lack of PA among older nursing home residents, and the importance of institutional capacity with regard to human resources and physical equipment for promoting PA among people with dementia, in particular. Policies and supports are needed to promote the implementation of healthy aging programs including PA for older nursing home residents. Such programs should be person-centered with consideration to the physical and cognitive status of individual residents.