• 제목/요약/키워드: mix design analysis

검색결과 238건 처리시간 0.03초

Optimization of mineral admixtures and retarding admixture for high-performance concrete by the Taguchi method

  • Chao-Wei Tang
    • Computers and Concrete
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    • 제32권2호
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    • pp.185-206
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    • 2023
  • This article aimed to explore the optimization of mineral admixtures and retarding admixture for high-performance concrete. In essence, fresh concrete can be regarded as a mixture in which both coarse and fine aggregates are suspended in a cement-based matrix paste. Based on this view, the test procedure was divided into three progressive stages of binder paste, mortar, and concrete to explore their rheological behavior and mechanical properties respectively. At each stage, there were four experimental control factors, and each factor had three levels. In order to reduce the workload of the experiment, the Taguchi method with an L9(34) orthogonal array and four controllable three-level factors was adopted. The test results show that the use of the Taguchi method effectively optimized the composition of high-performance concrete. The slump of the prepared concrete was above 18 cm, and the slump flow was above 50 cm, indicating that it had good workability. On the other hand, the 28-day compressive strength of the hardened concretes was between 31.3-59.8 MPa. Furthermore, the analysis of variance (ANOVA) results showed that the most significant factor affecting the initial setting time of the fresh concretes was the retarder dosage, and its contribution percentage was 62.66%. On the other hand, the ANOVA results show that the most significant factor affecting the 28-day compressive strength of the hardened concretes was the water to binder ratio, and its contribution percentage was 79.05%.

大学生在线学习效果的多维度比较研究

  • Lijuan Huang;Xiaoyan Xu
    • Journal of East Asia Management
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    • 제4권2호
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    • pp.39-62
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    • 2023
  • Online and offline mixed teaching mode has become an important way to promote the connotative development of higher education. Under the background that offline teaching has become mature, in order to further promote the development of online education, and promote the implementation of the mixed teaching mode, to mix and to provide basis for the construction of the mixed teaching mode, this study takes the online learning effect as the evaluation basis, adopts the online questionnaire survey to conduct statistical analysis of the online learning behavior of 2213 college students, and discusses the differentiation phenomenon of online learning groups from the micro, meso and macro perspectives. It is found that there are significant differences in the online learning effect of college students in terms of the type of learning platform, whether the school implements the online offline mixed teaching mode, education background, grade (bachelor's degree), and region. Colleges and universities should strengthen the promotion of online and offline mixed teaching mode; The online learning platform should improve the platform function and strengthen the functional differentiation design of learning resources for students. Education departments pay attention to the learning effect of online learners in different regions, and bridge the gap in regional education.

Box-willson 실험계획법 기반 고강도 자기충전형 콘크리트의 최적설계방법 (Box-Wilson Experimental Design-based Optimal Design Method of High Strength Self Compacting Concrete)

  • 도정윤;김두기
    • 한국구조물진단유지관리공학회 논문집
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    • 제19권5호
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    • pp.92-103
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    • 2015
  • Box-Wilson 실험계획법은 보통 중심합성계획법으로 알려져 있으며, 변동성이 존재하는 정보를 실험 계획적 방법으로 수집하는 설계 기법이다. 이 방법은 최소의 설계비용으로 가능한 많은 정보를 얻는 목적으로 고안되었다. 본 연구에서는 60 MPa급 고강도 자기충전형 콘크리트(HSSCC)를 대상으로 다양한 성능에 대한 여러 배합인자들의 효과를 효율적으로 파악하고 최적배합을 찾는 과정에 이 방법을 적용하였다. HSSCC의 배합인자(요인)와 물리적 성능(반응) 사이의 비선형적 관계는 2차 다항식으로 반응표면을 근사화 모델링하였으며, 요인점=25=32개, 축점=2k=10개, 중심점은 각 축에서 2번 씩 10개, 총 52개의 실험점에서 물시멘트비, 단위시멘트량, 잔골재비, 단위플라이애쉬량, 단위고성능감수량의 총 5개의 인자에 따른 압축강도, 통과능력, 재료분리저항성, 제조비용, 밀도 등의 총 5개의 반응을 파악하기 위한 실험이 실시되었다. 연구의 결과 Box-Wilson 실험계획법은 배합인자와 반응 사이의 관계를 과학적인 방법으로 계획하고 객관적으로 해석하는 데 매우 효과적이었으며, 수치해석적인 방법으로 최적배합을 계산할 수 있었다.

A Study on The Usability Evaluation Based on Text Analysis for The Development of Comfort-Shoes for Middle-Aged

  • KIM, Ji Ho;YOON, Sang Hoon;KWON, Ki Hyun;SEO, Jeong Kwon;HAN, Seung Jin
    • Journal of Sport and Applied Science
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    • 제3권2호
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    • pp.17-27
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    • 2019
  • Purpose: This study is to conduct usability evaluations from the perspective of developing comfort-shoes for the middle-aged and elderly to identify key factors and derive implications for optimal comfort-shoes production. Research design, data, and methodology: A total of 10 middle-aged and elderly women in their 50s and 60s were selected as eligible for the rescue. For data collection, the study was conducted in a Gang Survey, where pre-explanations, shoes test, and interviews were conducted. The collected data were analyzed in a total of four stages. In step 1, the contents obtained through interviews with the subjects were recorded in text, organized and analyzed systematically, and in step 2, unnecessary vocabulary, sentences, and overlapping opinions were eliminated. In step 3, we classified areas around key functions and carried out categorization tasks. Finally, in Step 4, the results and implications of the study were derived by classifying each usability evaluation shoe as positive and negative text around categorized data. Results: There are a total of seven factors for comfort-shoes usability evaluation, which are categorized as cushion, fitting, stability, flexibility, lightweight, comfort, and pressure. Positive/negative factors for the derived usability evaluation factors were shown in the form of a positive-centered, negative-centered, and positive-mixed mix for each of the four products. Positive-focused products are VA products, which are seven times more positive than negative factors. Negative-centered products are CL and SA products, which are five times more negative than positive factors. Positive mixing was a CA product with a ratio of 1:1. Text-based usability evaluations allow us to proceed with analysis based on more scientific data rather than simply listening to opinions and judging by comments. Conclusions: The study discussed implications of developing comfort-shoes for middle-aged consumers and future directions were discussed.

간병인을 위한 기능적 유니폼 개발 -노인의료복지시설 간병인을 대상으로- (Development of Functional Uniform for Caregivers)

  • 이은영;최혜선;김은경
    • 한국의류학회지
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    • 제31권5호
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    • pp.788-800
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    • 2007
  • The purpose of this study was to develop a caregiver's uniform that is appropriate for nursing and to improve movement adaptability as well as having a pleasing appearance. Based on the results of preliminary study, I investigated the inconvenience and problems with the existing uniforms and made a sample uniform taking into consideration the design, the material, and the pattern. We carried out a sensory assessment and quantitative assessment in order to compare the sample uniform with existing uniforms. Following are the results of this research. The top is a short-sleeved blouse with a round neckline having no collar and with armpit gussets. The armpit gussets are semicircles and the inverted pleats in the back are an improvement designed for activity. The pants are long reaching to the ankles with elastic in the waist so that the waist measurement may be adjusted. The length of the pants can be adjusted with strings and the pants have a funnel-shaped pocket for adjustment of length. We used a mix of polyurethane and polyester for the outer cloth of the uniform in order to improve activity function and used $Coolever^{TM}$, the sanitary textile that absorbs moisture well and dries in a short time, for gussets in the armpits, which is the heavy sweat area. The appearance assessment and movement adaptability assessment were performed with 5 subjects and 9 experts. For the results of the assessment, the sample uniform was appraised to be better than the existing uniforms in every item of an appearance comparison assessment except for the neckline assessment by the experts. As for the assessment of movement appropriateness and wearing assessment, the same subjects were used for analysis. As the results of the assessment, the sample uniform was rated higher than the existing uniforms in movement adaptability and pleasing appearance.

티셔츠 상품에 활용된 원 포인트 그래픽의 시각이미지 분석 (The Analysis of Visual Image of One-Point Graphic Appeared on T-shirt)

  • 이미연
    • 복식
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    • 제55권8호
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    • pp.15-29
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    • 2005
  • In these days, T-shirt is not only the simple wearing goods but also the suggestive communication, which is not showed outward as well as being intended. Also, it indicates expression of contemporary sensitive living, expression of substantial oneself, and the effective commercial promotion fer advertising fashion brand and promoting the object's sale. Following the above concept, the aim of this study is to understand the outstanding tendency of ' The T-shirt one-point graphic's functions and visual image ', which is appeared after 2001 in the fashion industry's commercial aspects. The visual image's applicative rate of the T-shirt one point graphic is the following; The best applicative rate on T-shirt one- point graphic is the visual image using the mix & match technique shown 42.8 percent applicative rate. The second one is the visual image using the typography shown 38.7 percent. The third one is the visual image using the animals and plants shown 8.5 percent. The fourth one is the visual image using the person's character shown 3.8 percent. The fifth one is the visual image using the geometry shown 2.4 percent. The least one is the visual image using the cartoon character shown 1.6 percent. On the other hand, another important function of t-shirt one-point graphic is the following; 1, The essential function as t-shirt design factor. 2, The promotional function as brand image marketing and brand advertisement. 3. The communicative function as discriminative strategy of object. 4. The achievable function as value added goods.

현대 니트 패션에 표현된 젠더 플루이드 특성 연구 (A study on the characteristics of gender fluidity expressed in modern knit fashion)

  • 이연지;엄소희
    • 복식문화연구
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    • 제31권1호
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    • pp.91-106
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    • 2023
  • This study examines how the concept of gender fluidity-viewing gender identity as a fluid and wide spectrum-is represented in modern knit fashion collections. The period spring/summer 2017-fall/winter 2021, when gender-related fashion keywords started attracting attention, was limited to the last five years, and the results of a case analysis focused on a total of 357 knit fashion photos are as follows. First, the androgynous compromise through the mixing of heterogeneous elements appears as a mix-and-match style due to the patchwork of heterogeneous materials and forms that borrow or share masculinity and femininity. Second, it was confirmed that the dismantling exaggeration caused by the destruction of the size and form of clothes was an avant-garde image that exaggerated the size or length of clothes or destroyed ideas and forms. Third, the exposed sensuality caused by the deformation of the fluid knitting technique was shown in the form of proudly expressing sexuality by exposing the body either using the cut-out technique or through the loose texture of the knit. Knit fashion can highlight decorative effects using handcrafted techniques and express a detailed or coarse sense of organization depending on the density. In addition, since it is possible to create a complex image by juxtaposing and mixing various knit structures, it was confirmed that it is a suitable material for expressing gender fluidity flowing between men and women in fashion.

우유 Packaging 색채 마케팅전략 (Color Marketing Strategy of Milk Packaging)

  • 김경화;나지영
    • 한국콘텐츠학회논문지
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    • 제12권1호
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    • pp.197-210
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    • 2012
  • 본 논문에서는 소비자들이 우유 제품을 구매시 Packaging 디자인 요소가 어떠한 영향을 미치는 가를 파악하기 위해 수도권 지역에 거주하고 있는 성인남녀 중 유제품을 구입한 경험이 있는 소비자 120명을 연구대상으로 선정하였다. 수집된 자료의 통계처리는 SPSS 12.0 for Windows 통계 패키지 프로그램을 이용하여 빈도분석과 평균과 표준편차의 기술통계량을 이용하여 산출하였다. 또한, 우유패키지 디자인을 선정하기 위해 2010년 한국리서치 소비자 정성 조사 보고서 자료와 예비조사를 토대로 출시되고 있는 전체 일반우유 패키지 디자인 중 가장 선호하는 3가지 제품과 가장 비선호하는 3가지 제품을 선정하였다. 아울러, 초코와 딸기 우유 중 가장 선호하는 우유 3가지를 선정하여 연구대상으로 선정하였다. 분석결과는 첫째, 소비자들의 우유제품 구매시 가장 고려하는 사항은 가격으로 나타났고, 둘째, 소비자들의 시중 우유패키지 디자인에 대한 평가는 우유제품의 포장 디자인에서 중요한 사항으로는 색채가 3.81점으로 가장 높게 조사되었다. 셋째, 각 제품별 우유 패키지 디자인에 대한 평가를 분석한 결과, 우유 제품 패키지 디자인은 복잡하지 않은 것으로 평가되었다. 또한, 전체 9개의 제품을 평가한 결과 1번 우유(남양: 맛있는 우유)가 다른 8개의 우유에 비하여 매우 높은 평가를 보였고, 이는 우유제품의 선택에 있어 색채패키지 디자인이 중요한 역할을 하는 것으로 풀이된다. 따라서 본 연구에서는 색채마케팅 전략을 다음과 같이 설정하였다. 첫째, 패키지 디지인의 특성을 강조할 수 있도록 심미적 호감, 정보전달, 생태계 보호, 홍보 강화 등의 기능역할을 강화, 둘째, 색채가 부여하는 심리적 내지 생리적 효용, 커뮤니케이션 매체로서 시각전달에 사용하는 효용 이외에 상품의 이미지를 전달할 수 있는 색채마케팅 전략을 구축, 셋째, 기업 이미지 통합을 위한 색채마케팅 전략을 구축하고, 마지막으로 기업과 제품 스타일에 적합한 색채를 구성해야 하며, 기업색채를 활용한 디자인마케팅을 도입해야 한다.

혼합 기능을 갖는 마이크로 펌프의 연구 (A Study on the MHD Micropump with Mixing Function)

  • 최범규;강호진;김민석
    • 대한기계학회논문집B
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    • 제34권6호
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    • pp.579-586
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    • 2010
  • MEMS 기술의 향상과 함께 $\mu$-TAS(Micro Total Analysis System)가 개발 되어 의료 및 생물학 분야가 급속하게 성장했다. $\mu$-TAS의 한 분야로 Chip 위에서 소량의 sample과 반응물을 가지고 혼합공정과 분석공정이 이루어지는 LOC(Lab on a chip)에 관한 연구는 활발하게 연구되어진다. LOC는 마이크로 펌프 와 마이크로 믹서와 같은 microfluidic 장치들로 구성된다. Microfluidic 시스템의 유동이 층류 유동이므로 유체상태의 반응물들을 효율적으로 혼합하고 공급하는 것이 어렵다. 본 논문은 이송 및 혼합이 동시에 이루어지는 MHD micropump의 설계와 제작에 관해 제시하였다. 최종 개선사양은 상용 CFD 프로그램의 해석결과를 통하여 결정하였다.

실측 및 해석모델에 의한 철근콘크리트조 주상복합건물의 모드특성 (Modal Properties of a Tall Reinforced Concrete Building Based on the Field Measurement and Analytical Models)

  • 김지영;김주연;김미진;유은종;김대영
    • 한국전산구조공학회논문집
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    • 제22권3호
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    • pp.289-296
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    • 2009
  • 건축구조물의 고유진동수는 지진하중 혹은 풍하중의 크기를 결정하고 바람에 의한 진동을 예측하여 사용성조건을 검토하기 위해 반드시 필요하다. 본 논문에서는 철근콘크리트조 주상복합건물을 대상으로 현장계측을 통해 얻은 데이터와 시스템 식별기법을 사용하여 얻은 고유진동수와 모드형상을 해석모델에 의한 결과와 비교하였다. 해석모델은 실무에 일반적으로 사용되어지는 PC기반의 유한요소해석 프로그램을 사용하여 작성하였으며, 골조만을 모델링한 기본모델로부터 계측당시 구조물의 강성에 영향을 미칠 것으로 판단되는 요소들을 단계적으로 포함시켜 가면서 그 결과를 계측치에서 얻은 값과 비교하였다. 기본모델로부터 수정된 사항은 1) 콘크리트 배합강도를 고려한 탄성계수의 보정, 2) 바닥 슬래브의 휨강성, 3) 비구조벽이다. 이와 같은 요소를 모두 포함한 해석모델은 실제 계측치로부터 얻은 고유진동수, 모드형상과 가장 유사한 결과를 나타내었다.