• Journal of Ecology and Environment
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• 제43권2호
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• pp.246-253
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• 2019

Background: Water use efficiency (WUE) is an indicator of the trade-off between carbon uptake and water loss to the atmosphere at the plant or ecosystem level. Understanding temporal dynamics and the response of WUE to climatic variability is an essential part of land degradation assessments in water-limited dryland regions. Alternative definitions of and/or alternative methodologies used to measure WUE, however, have hampered intercomparisons among previous studies of different biomes and regions. The present study aims to clarify semantic differences among WUE parameters applied in previous studies and summarize these parameters in terms of their definition and methodology. Additionally, the consistency of the responses of alternative WUE parameters to interannual changes in moisture levels in Northeast Asia dryland regions (NADRs) was tested. Results: The literature review identified more than five different WUE parameters defined at leaf and ecosystem levels and indicates that major conclusions regarding the WUE response to climatic variability were partly inconsistent depending on the parameters used. Our demonstration of WUE in NADR again confirmed regional inconsistencies and further showed that inconsistencies were more distinct in hyper- and semi-arid climates than in arid climates, which might reflect the different relative roles of physical and biological processes in the coupled carbon-water process. Conclusions: The responses of alternative WUE parameters to drying and wetting may be different in different regions, and regionally different response seems to be related to aridity, which determines vegetation coverage.

• Wind and Structures
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• 제19권3호
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• pp.233-247
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• 2014

Vortex-induced oscillation is a type of aeroelastic phenomenon, to which extended structures such as long-span bridges are most susceptible. The vortex-induced vibration (VIV) behaviors of a concerned bridge were investigated conventionally in virtue of wind tunnel tests on string-mounted sectional models. This necessitates the building of a linkage between the response of the sectional model and that of the prototype structure. Although many released literatures have related to this issue and provided suggestions, there is a lack of consistency among them. In this study, some theoretical models describing the vortex-induced structural motion, including the linear empirical model, the nonlinear empirical model and the modified (or generalized) nonlinear empirical model, are firstly reviewed. Then, the concept of equivalent mass density is introduced based on the principle that an equal input of energy should result in identical structural amplitudes. Based on these, the theoretical linkages between the amplitude of a section model and that corresponding to the prototype bridge are discussed with different analytical models. Theoretical derivation indicates that such connections are dependent mainly on two factors, one is the presupposed shape of deformation, and the other is the theoretical VIV model employed. The theoretical analysis in this study shows that, in comparison to the nonlinear empirical models, the linear one can result in obvious larger estimations of the full bridges' responses, especially in cases of cable-stayed bridges.

• Advances in nano research
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• 제7권6호
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• pp.419-429
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• 2019

The effect of an increasing percentage of nanofiller (glass cenosphere) with Glass/Epoxy hybrid composite curved panels modeled mathematically using the multiscale concept and subsequent numerical eigenvalues of different geometrical configurations (cylindrical, spherical, elliptical, hyperboloid and flat) predicted in this research article. The numerical model of Glass/Epoxy/Cenosphere is derived using the higher-order polynomial type of kinematic theory in association with isoparametric finite element technique. The multiscale mathematical model utilized for the customized computer code for the evaluation of the frequency data. The numerical model validation and consistency verified with experimental frequency data and convergence test including the experimental elastic properties. The experimental frequencies of the multiscale nano filler-reinforced composite are recorded through the impact hammer frequency test rig including CDAQ-9178 (National Instruments) and LABVIEW virtual programming. Finally, the nano cenosphere filler percentage and different design associated geometrical parameters on the natural frequency data of hybrid composite structural configurations are illustrated through a series of numerical examples.

• Geomechanics and Engineering
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• 제25권4호
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• pp.303-315
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• 2021

A rigorous and generic similarity solution is developed for assessment of the undrained expansion responses of a cylindrical cavity expansion in K₀-consolidated anisotropic soils. A K₀-consolidated anisotropic modified Cam-clay (K₀-AMCC) model that can represent the initial stress anisotropy and the effects of stress-induced anisotropy is used to model the soil behaviors during cavity expansion. All the seven basic unknowns, the three stress components, the pore water pressure, the particle velocity, the specific volume and the hardening parameter, are reduced to the functions of a dimensionless radial coordinate and are taken as coupled variables to formulate the problem. The governing equations are formulated by making use of the equilibrium equation, the constitutive equation, the consistency condition, the continuity condition and the undrained condition, which are then solved as an initial value problem. The proposed rigorous similarity solution is compared with some well-documented rigorous solutions to validate the solution and to highlight the special expansion responses in anisotropic soils. The results reveal that the present solution can yield more predictions for cavity expansion problems in soils with initial anisotropic stresses.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2001년도 추계학술대회 논문집
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• pp.104-111
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• 2001

정서와 생리반응 (자율신경계 반응) 간의 관계에 관하여 성인을 대상으로 최근가지 많은 연구가 행해져 왔다. 본 연구에서는 동일한 실험참여자를 대상으로 일정 기간 동안 여러 회의 반복실험을 통해 정서(기쁨, 슬픔, 분노, 공포, 혐오)에 따른 자율신경계의 반응의 일관성과 정서별 자율신경계 반응 패턴을 규명하고자 하였다. 본 실험에 앞서 저서를 유발하기 우한 도구인 정서유발자극세트와 정서에 대한 심리반응을 평가하기 위한 정서평가척도가 제작되었다. 정서유발자극세트는 2-4분 정도의 각 정서 장면이 포함된 총 5개의 동영상 장면들이다. 예비실험을 통해 70％ 이상의 적합성 및 효과성을 가진 4개의 세트를 추출하여 본 실험에 사용하였다. 본 실험은 남녀 대학생 12명을 대상으로 4회 반복해서 실시되었다. 실험참여자들은 각 정서 장면을 시청 후, 유발된 정서에 대한 심리적인 평가를 하였다. 측정한 자율신경계 생리반응 변수는 ECG, PPG, EDA, SKT이었다. 연구 결과, 심리반응에서 정서유발자극세트는 75％ 이상의 적합성 및 효과성을 보였다. 생리반응(ECG, EDA) 분석 결과, 정서에 따른 자율신경계 반응은 회기별로 일관적이었으며, 각 정서별로 특정적인 생리반응 패턴을 가지는 것으로 나타났다.

• 한국식품조리과학회지
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• 제15권6호
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• pp.591-594
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• 1999

찹쌀가루의 첨가수준을 0%, 10%, 20%, 30%, 40%, 50%로 달리하여 제조한 산약병의 기계적 측정 및 관능적 특성을 통해 품질평가를 하였다. 산약병의 수분함량은 찹쌀가루의 첨가량이 증가함에 따라 수분함량은 감소하는 것으로 나타났다. 색도의 것을 L 값은 찹쌀가루 첨가량이 많아질수록 증가하였으나, a 값과 b 값은 감소하는 것으로 나타나, 이는 마가루에 함유된 단백질 함량의 영향 및 마가루 자체의 색으로 인해 마를 첨가할수록 육안으로 보기에도 검어지며, 황색도 및 적색도가 증가하는 것으로 판단할 수 있었다. Two bite compression test에 의한 텍스쳐 특성치를 살펴보면, hardness, gumminess, chewiness, cohesiveness 등은 찹쌀가루의 첨가량이 증가할수록 감소하는 경향을 나타냈고, springiness는 각 시료간의 큰 차이를 보이지 않아, 마가루의 함량이 높을수록 조직이 잘 결착되며 점성을 띄는 것을 알 수 있었다. 관능검사 결과에서는 항목별로 유의적인 차이를 나타냈는데, 색의 것은 10% 첨가한 것을, 향미는 20% 첨가한 것을, 맛은 40% 첨가한 것을 가장 선호하는 것으로 나타났다. 구강 내에서의 조직특성을 나타내는 adhesivenes와 consistency 역시 유의적인 차이를 나타냈는데, adhesiveness 및 consistency의 경우 40% 첨가한 것을 가장 선호하는 것으로 나타났다. 이는 마의 함량이 높을수록 점성이 증가하게 되는데, 일반적으로 떡을 먹을 때 이에 달라붙어 점착성이 큰 것보다는 부드러운 것을 선호함을 알 수 있었다. Overall acceptance의 경우, 40% 첨가한 것을 선호하는 것으로 나타나 찹쌀가루가 40% 정도 첨가되는 것이 바람직할 것으로 보인다.

• 한국안전학회지
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• 제39권1호
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• pp.62-69
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• 2024

Ensuring swift on-site access to fire engines is crucial in preserving the golden time and minimizing damage. However, various mobility constraints in alleyways hinder the timely entry of fire engines to the fire scene, significantly impairing their initial response capabilities. Therefore, this study analyzed the significant mobility constraints of fire engines, focusing on Seoul, which has many old town areas. By leveraging survey responses from firefighting experts and actual observations, this study quantitatively assessed the frequency and severity of mobility constraint factors affecting the disaster responses of fire engines. Survey results revealed a consistent set of top five factors regarding the frequency and disturbance level, including illegally parked cars, narrow paths, motorcycles, poles, and awnings/banners. A comparison with actual road-view images showed notable consistency between the survey and observational results regarding the appearance frequency of mobility constraint factors in vulnerable areas in Seoul. Furthermore, the study emphasized the importance of tailored management strategies for each mobility constraint factor, considering its characteristics, such as dynamic or static. The findings of this study can serve as foundational data for creating more detailed fire safety maps and advancing technologies that monitor the mobility of fire engines through efficient vision-based inference using CCTVs in the future.

• 대한한방소아과학회지
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• 제38권2호
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• pp.1-10
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• 2024

Objectives This study aimed to assess the reliability and validity of the Five-Visceral Weak Children Questionnaire (FWCQ) in childhood anorexia and to propose optimal cutoff values. Methods We conducted two surveys, spaced one month apart, targeting the parents of 366 children aged 2-9 years who had been diagnosed with anorexia for at least one month. To evaluate the reliability of the FWCQ, we calculated Cronbach's alpha coefficient and employed the test-retest method. Additionally, correlation analysis was performed between the FWCQ and each visceral question, and discriminant validity was assessed by comparing responses from the anorexic and normal groups. Furthermore, we determined the cutoff value of the spleen weak score, which is closely associated with appetite, for the anorexic group. Results The first survey yielded responses from 336 participants, followed by 171 responses in the second survey conducted one month later. The FWCQ demonstrated high internal consistency (Cronbach's alpha = 0.776), and test-retest results were consistent. The correlation coefficients between the FWCQ and each visceral question were all statistically significant. Moreover, significant discriminant validity was observed between the anorexic and normal groups in the FWCQ score and the heart, spleen, and kidney weak scores. The optimal cutoff value for the spleen weak score in the anorexic group was found to be 5.5 points (with a sensitivity of 73.44% and specificity of 66.47%). Conclusions The FWCQ exhibited strong reliability and validity in children with anorexia.

• 품질경영학회지
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• 제40권2호
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• pp.156-165
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• 2012

The objective of this study is to identify the critical dimensions of comprehensive quality and to prioritize them for improvement of the quality competitive advantage. The critical dimensions, sub-dimensions and measurement items of comprehensive quality were abstracted from literature of quality, and constructed a model of hierarchical structure. 115 experts in four groups(supplier, buyer, consultant, and professor) were participated in pair-wise comparison of quality dimensions, but some of these responses were removed because the overall consistency of evaluator judgements exceed the acceptable ratio of 0.10. The priorities of quality dimensions for industrial and consumption goods were calculated respectively using the analytic hierarchy process(AHP) approach. As a result, product quality had the highest weight of 0.65, followed by support quality(0.18) and service quality(0.17) for industrial goods while product quality also had the highest weight of 0.62, but service quality(0.22) was preferred over support quality(0.16) for consumption goods.

• 한국의류학회지
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• 제23권8호
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• pp.1098-1109
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• 1999

This study was to examine the effects of textiles materials and wearing types on the thermal regulation responses of human, Cotton polyester wool silk and rayon were chosen as outerwears and acetate was selected as a lining. Blouse-skirt suits blouse-slacks suits and one-piece dress made of selected textiles were examined by human trials, Tests results were as follows ; 1 When subjects wore vlouse-slacks suits Tmsk was showed the highest value. There was a significant difference on Tmsk(p<0.05) when they wore one-piece dress. The temperature of microclimate inside clothing when subjects wore blouse-slacks suits showed the highest value and one-piece dress and then blouse-skirt suits in order. For blouse-skirt suits clothing without lining showed higher temperature of the back of microclimate inside clothing than clothing with lining except cotton(p<0.1) 2. There were no significant consistency of the increasing rates of thermal insulation of garment at fabric test and human trials among polyesterand silk.