• Title/Summary/Keyword: Multiple Comparison

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A study of single-phase liquid cooling by multiple nozzle impingement on the smooth and extended surfaces (다중노즐에 의해 분사된 평면 및 확장면의 단상액체냉각에 관한 연구)

  • 소영국;박복춘;백병준
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.10 no.6
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    • pp.743-752
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    • 1998
  • Experiments were performed to characterize single-phase heat transfer behavior of submerged liquid jet with multiple nozzle normally impinging on the smooth and extended surfaces. Arrays of 9 and 36 nozzles were used, with diameters of 0.5 to 2.0mm providing nozzle area ratio (AR) from 0.05 to 0.2. The square pin fin arrays were chosen as extended surfaces and the effects of geometrical parameters such as fin height, the ratio of fin width to channel width on heat transfer enhancement were examined. Single nozzle characteristics were also evaluated for comparison. The results clearly showed that heat transfer enhancement could be realized by using multiple nozzles at the constant volume flow rate. The average Nusselt number of multiple nozzle impingement on the smooth surface was correlated by the following equation : Nu/$Pr\frac{1}{3}=0.94 Re^{0.56}N^{-0.12}AR^{0.50}$The average heat transfer coefficients of multiple nozzle impingement on the extended surfaces decreased with increasing fin height and the ratio of fin width to channel width. The effectiveness of ex-tended surfaces ranged from 1.5 to 3.5 depending on the fin height, the ratio of fin width to channel width of pin fin arrays, nozzle number and nozzle area ratio.

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Multiple intelligences and critical thinking disposition in nursing students (간호학생의 다중지능과 비판적 사고 성향)

  • Hwang, Eunhee;Shin, Su Jin
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.21 no.4
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    • pp.433-445
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    • 2014
  • Purpose: This study was conducted to examine relationships between critical thinking disposition and multiple intelligences. Method: Participants were nursing students (N=186) who completed a questionnaire assessing critical thinking disposition and multiple intelligences. Data were analyzed using descriptive statistics, t-test, analysis of variance with post hoc comparison, and Pearson correlation coefficients. Results: For type of multiple intelligences, 32.9% of students had the strongest fit for "interpersonal intelligence" type and 20.1% for "intrapersonal intelligence" type. Mean score for critical thinking disposition was $3.42{\pm}0.37$. Factors related to critical thinking disposition were participation in club activities (F=5.962, p=.001) with a representative role in the club (t=2.140, p=.034). There were significant differences in interpersonal intelligence scores by personality traits (t=2.445, p=.015), participation in club activities (F=10.003, p<.001), and friendship (t=2.539, p=.012); and significant differences in intrapersonal intelligence scores by participation in club activities (F=3.862, p=.010), having a representative role in the club (t=2.101, p=.037), and friendship (t=2.220, p=.029). Conclusion: Results indicate that critical thinking disposition is significantly associated with multiple intelligences and suggest that multiple intelligences should be considered to enhance critical thinking disposition when tailored teaching is adopted in nursing education.

A Novel Approach towards use of Adaptive Multiple Kernels in Interval Type-2 Possibilistic Fuzzy C-Means (적응적 Multiple Kernels을 이용한 Interval Type-2 Possibilistic Fuzzy C-Means 방법)

  • Joo, Won-Hee;Rhee, Frank Chung-Hoon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.24 no.5
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    • pp.529-535
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    • 2014
  • In this paper, we propose a hybrid approach towards multiple kernels interval type-2 possibilistic fuzzy C-means(PFCM) based on interval type-2 possibilistic fuzzy c-means(IT2PFCM) and possibilistic fuzzy c-means using multiple kernels( PFCM-MK). In case of noisy data or overlapping cluster prototypes, fuzzy C-means gives poor performance in comparison to possibilistic fuzzy C-means(PFCM). Moreover, to address the uncertainty associated with fuzzifier parameter m, interval type-2 possibilistic fuzzy C-means(PFCM) is used. Most of the practical data available are complex and non-linearly separable. In such cases using Gaussian kernels proves helpful. Therefore, in order to overcome all these issues, we have integrated multiple kernels possibilistic fuzzy C-means(PFCM) into interval type-2 possibilistic fuzzy C-means(IT2PFCM) and propose the idea of multiple kernels based interval type-2 possibilistic fuzzy C-means(IT2PFCM-MK).

Analysis of Cutting Properties with Reference to Amount of Coolant used in an Environment-Conscious Turning Process

  • Yang, Seung-Han;Lee, Young-Moon;Kim, Young-Suk
    • Journal of Mechanical Science and Technology
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    • v.18 no.12
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    • pp.2182-2189
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    • 2004
  • In the recent years, environmentally conscious design and manufacturing technologies have attracted considerable attention. The coolants, lubricants, solvents, metallic chips and discarded tools from manufacturing operations will harm our environment and the earth's ecosystem. In the present work, the Tukey method of multiple comparisons is used to select the minimum level of coolant required in a turning process. The amount of coolant is varied in 270 designed experiments and the parameters cutting temperature, surface roughness, and specific cutting energy are carefully evaluated. The effects of coolant mix ratio as well as the amount of coolant on the turning process are studied in the present work. The cutting temperature and surface roughness for different quantity of coolant are investigated by analysis of variance (ANOVA) - test and a multiple comparison method. ANOVA-test results signify that the average tool temperature and surface roughness depend on the amount of coolant. Based on Tukey's Honestly Significant Difference (HSD) method, one of the multiple comparison methods, the minimum level of coolant is 1.0 L/min with 2% mix ratio in the aspect of controlling tool temperature. F-test concludes that the amount of coolant used does not have any significant effect on specific cutting energy. Finally, Tukey method ascertains that 0.5 L/min with 6% mix ratio is the minimum level of coolant required in turning process without any serious degradation of the surface finish. Considering all aspects of cutting, the minimum coolant required is 1.0 L/min with 6% mix ratio. It is merely half the coolant currently used i.e. 2.0 L/min with 10% mix ratio. Minimal use of coolant not only economically desirable for reducing manufacturing cost but also it imparts fewer hazards to human health. Also, sparing use of coolant will eventually transform the turning process into a more environment-conscious manufacturing process.

Comparative research on the preferences and choices of distribution channels depending on the consumption characteristics on fashion consumer - Focused on active Korean and Chinese seniors - (패션 소비자의 유통채널 선호 및 소비 특성에 따른 유통채널 선택에 관한 비교연구 - 한·중 액티브 시니어 비교를 중심으로 -)

  • Sang In Lee;Jihun Yu
    • The Research Journal of the Costume Culture
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    • v.31 no.3
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    • pp.361-378
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    • 2023
  • This research not only determined the preference of fashion brand distribution channels of active Korean and Chinese seniors who became major consumers in the fashion industry, but also analyzed the effect on these preferences and choices of distribution channels depending on personal consumption characteristics and differences between the two groups. Data was collected by a professional survey firm. SPSS 24.0 and AMOS 24.0 were used for empirical analysis, and frequency analysis, multiple response analysis, EFA, reliability analysis, CFA, SEM, and multiple-group comparison analysis were performed. As a result of multiple response analysis, the offline channel was revealed as the preferred fashion distribution channel for active Korean and Chinese seniors; the second most popular was the online channel. The results of multiple-group comparison analysis reveal differences between two groups in seeking emotional consumption via the offline channel; the effect was only evident for active Korean seniors. A difference in seeking emotional consumption via preference for online channel also existed, but only for active Chinese seniors. For these reasons, marketers targeting active Korean seniors will be effective to not only offer brand information by fashion display to let seniors understand the fashion brand, but also to have brand events to form positive emotions toward the fashion brand. Moreover, targeting active Chinese seniors will be necessary to transmit brand sensibility by utilizing metaverse marketing comprising various factors, so that consumers can enjoy the fashion brand.

The Effects of Mass Media, Tendency for Appearance Comparison and BMI on Female High School and College Students' Eating Behavior (대중매체, 타인과의 외모 비교 및 신체질량지수가 여고생 및 여대생의 섭식태도에 미치는 영향)

  • Kim, Jung-Min;Han, Guen-Hee
    • Journal of Families and Better Life
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    • v.26 no.4
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    • pp.73-83
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    • 2008
  • This study examines the effects of mass media, the tendency for young women to make body comparisons, and the BMI of female high school and college students on their attitudes about eating. Participants were 392 high school students from Gyeonggi Province and 391 college students from Seoul, Gyeonggi and Chung-nam Province. Collected data were analyzed through Cronbach's ${\alpha}$, t-test, One-way ANOVA, $Scheff{\acute{e}}$ test, Pearson's correlation, and stepwise multiple regression. The findings of the study were as follows: 1) While mass media influence differed by grade, tendency for appearance comparison and attitude toward eating did not differ by grade. 2) Mass media influence, tendency for appearance comparison and attitude toward eating differed by BMI. 3) Mass media pressure, specific attributes comparison, and BMI were significant predictors of attitudes toward eating. 4) Tendency for appearance comparison played a mediating role in the relationship between mass media and attitudes toward eating.

Comparison of the Tracking Methods for Multiple Maneuvering Targets (다중 기동 표적에 대한 추적 방식의 비교)

  • Lim, Sang Seok
    • Journal of Advanced Navigation Technology
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    • v.1 no.1
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    • pp.35-46
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    • 1997
  • Over last decade Multiple Target Tracking (MTT) has been the subject of numerous presentations and conferences [1979-1900]. Various approaches have been proposed to solve the problem. Representative works in the problem are Nearest Neighbor (NN) method based on non-probabilistic data association (DA), Multiple Hypothesis Test (MHT) and Joint Probabilistic Data Association (JPDA) as the probabilistic approaches. These techniques have their own advantages and limitations in computational requirements and in the tracking performances. In this paper, the three promising algorithms based on the NN standard filter, MHT and JPDA methods are presented and their performances against simulated multiple maneuvering targets are compared through numerical simulations.

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A Comparison of Young Children's Multiple Intelligence Area and Social Behaviors in Montessori and General Programs of Day Care Centers (몬테소리와 일반 어린이집 유아의 다중지능 영역비교와 사회성)

  • Jeon, Oh-Sook;Chong, Young-Sook;Jang, Hye-Ja
    • Korean Journal of Human Ecology
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    • v.15 no.1
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    • pp.71-81
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    • 2006
  • The purpose of this study is to examine the differences in young children's multiple intelligence and social behaviors based not only on Montessori and general programs of day care centers but also on their gender and social- demographic factors. The subjects were 329 young children (182 boys and 147 girls aged from four to five) from two day care centers in Cheongju city. The instruments used in this study were HAPI (Hillside assessment of Perceived Intelligence) to measure the surveyee's multiple intelligence and Park & Lee's scale to measure their social behaviors. The frequencies, percentiles, mean, standard deviations, Cronbach a, t-teat, F and LSD were used to analyze the collected data through SPSS WIN program. The results of this study are as follows: 1) As for young children's multiple intelligence, there are differences according to young children's gender, order of birth, parents' level of education and teacher's working period out of social-demographic factors. 2) As for the young children's social behavior, there are differences according to young children's gender, mother's level of education and teacher's working period out of social-demographic factors.

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Exact Bit Error Rate Calculation of UWB-TH PPM Multiple Access Communication systems (UWB-TH PPM 다중 통신시스템의 정확한 비트 오율의 계산)

  • Park, Jang-Woo;Cho, Sung-Eon;Choi, Yong-Suk
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.6
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    • pp.1174-1181
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    • 2005
  • The exact bit error rate(BER) calculation of an UWB-TH PPM multiple access communication system, which is known to be suitable for the fast transmission of massive information data, is introduced. The statistic feature of the multiple access intereference (MAI) of the system is precisely modeled by the characteristic function technique. The concrete expression for the MAI allows the exact expression for BER to be derived. In addition, we propose the approximate expression for the BER which reveals superior accuracy to the expression from the previous Gaussian approximation of the MAI. The validity of the proposed expressions is confirmed from the comparison of proposed results with the results from Monte-Carlo simulation.

Comparison of Efficiency between Two Auction Designs for CO2 Emission Allowances : Uniform Pricing vs. Multiple Pricing (탄소배출권 경매할당의 방법론에 대한 효율성 비교: 단일가격 결정방식 vs. 복수가격 결정방식)

  • Kim, Hyo-Sun;Yoo, Sang Hee
    • Environmental and Resource Economics Review
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    • v.19 no.1
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    • pp.23-43
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    • 2010
  • This article compares two different auction designs for $CO_2$ emission allowances, namely uniform pricing and multiple pricing, in view of market efficiency. Experimental economic method of Buckley et al. (2004) is applied in this analysis. As a result of this analysis as expected, multiple pricing method brings out Winner's curse. It means that uniform pricing method is more efficient than multiple pricing method.

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