• 품질경영학회지
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• 제46권3호
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• pp.651-658
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• 2018

Purpose: The algorithm described in Lim(1998) is available to determine the sample size directly given specified significance level, power and signal-to-noise ratio. We research on the efficient determination of the sample size by visual methods. Methods: We propose three graphs for investigating the mutual relationship between the sample size r, power $1-{\beta}$ and the detectable signal-to-noise ratio ${\Delta}$. First graph shows the relationship between ${\Delta}$ and $1-{\beta}$ for the given r and it can be checked whether the power is sufficient enough. Second graph shows the relationship between r and ${\Delta}$ for the given power $1-{\beta}$. Third graph shows the relationship between r and $1-{\beta}$ for the given ${\Delta}$. It can be checked that which effects are sensitive to the efficient sample size by investigating those graphs. Results: In factorial design, randomized block design and the split plot design how to determine the sample size directly given specified significance level, power and signal-to-noise ratio is programmed by using R. A experiment to study the split plot design in Hicks(1982) is used as an example. We compare the sample sizes calculated by randomized block design with those by split plot design. By using graphs, we can check the possibility of reducing the sample size efficiently. Conclusion: The proposed visual methods can help an engineer to make a proper plan to reduce the sample size.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제15권4호
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• pp.251-259
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• 2015

In this paper, a ship detection method is proposed; this method uses edge-based segmentation and histogram of oriented gradient (HOG) with the ship size ratio. The proposed method can prevent a marine collision accident by detecting ships at close range. Furthermore, unlike radar, the method can detect ships that have small size and absorb radio waves because it involves the use of a vision-based system. This system performs three operations. First, the foreground is separated from the background and candidates are detected using Sobel edge detection and morphological operations in the edge-based segmentation part. Second, features are extracted by employing HOG descriptors with the ship size ratio from the detected candidate. Finally, a support vector machine (SVM) verifies whether the candidates are ships. The performance of these methods is demonstrated by comparing their results with the results of other segmentation methods using eight-fold cross validation for the experimental results.

• 한국연소학회지
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• 제15권4호
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• pp.65-73
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• 2010

In order to provide fundamental information for developing reaction model in the practical blended coal power plants, effects of particle size and blending ratio on combustion characteristics and thermal reaction in co-firing with bituminous and sub-bituminous coals were experimentally investigated using a TGA and a laboratory-scale burner. Characteristic parameters including ignition, burnout temperature and activation energy were determined from TG and DTG combustion profiles. Distributions of flame length and mean particle temperature were investigated from the visualization of flames in slit-burner system. As coal particle size decreased and volatile matter content increased, characteristic temperatures and activation energy decreased. The ignition/burnout characteristics and activation energy are linearly influenced by a variation in particle size and blending ratio. These results indicated that the control of the coal blending ratio can improve the combustion efficiency for sub-bituminous coals and the ignition characteristics for bituminous coals.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권2호
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• pp.805-825
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• 2017

Correlation Filter-based Trackers (CFTs) gained popularity recently for their effectiveness and efficiency. To deal with the size changes of the target which may degenerate the tracking performance, scale estimation has been introduced in existing CFTs. However, the variations of the aspect ratio were usually neglected, which also influence the size of the target. In this paper, Size Aware Correlation Filter Trackers (SACFTs) are proposed to deal with this problem. The SACFTs not only determine the translation and scale variations, but also take the aspect ratio changes into consideration, thus a better estimation of the size of the target can be realized, which improves the overall tracking performance. And competing results can be achieved compared with state-of-the-art methods according to the experiments conducted on two large scale datasets.

• 대한인간공학회지
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• 제16권2호
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• pp.61-71
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• 1997

In industrial designing of ready-to-wear shoes, one important factor to consider is that the population has diverse fooot shapes as well as foot length. The general shape of a foot could be represented by "foot ratio", i.e. the ratio of width to length. In this study, we measured several dey aspects of young Korean men's foot, and compared the results with their shoe sizes and general foot shapes. To this end, 172 male subjects were categorized according to their shoe size (small, medium, large) or foot ratio (wide, narrow, intermediate). The statistics of this survey indicated that the people with narrow foot shap have significantly greater foot length compared with the one having wide foot shape. Conversely, subjects having wide foot shape manifested significantly greater foot and ankle girth as well as significantly greater foot breadth. However, different foot shape groups showed no significant differences in heel width, heel ankle girth, instep height, and malleolus height. On the other hand, subjects wearing larger shoe size showed significantly larger foot measurements except instep and ankle heights, whereas subjects with shoe sizes 260 and below measured significantly more narrow heel and lateral metatarsal breadths. The deviation between foot length and dress shoe size(length) was greater in groups with wide foot shape and in groups wearing large shoe sizes. The results of this survey indicated that the subjects with wide foot shape apparently choose a size or two larger shoes for them as a compromise for a better breadth fit.eadth fit.

• 한국정밀공학회지
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• 제20권1호
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• pp.214-221
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• 2003

In this study, based on the effect of the interaction of fracture mechanics by graphite and fatigue limit phenomena of the microscopic observation various matrix structure, spheroidal ratio, size of graphite and distribution etc. parameters containd with Ductile Cast Iron. Therefore, in this study, different ferrite-pearlite matrix structure and spheroidal ratio of graphite of 70%, 80% and 90%, GCD40, GCD45-1 and GCD45-2 series and three different ferrite-pearlite matrix structure, GCD 45-3, GCD 50, GCD 60 series, all of which contain more than 90% spheroidal ratio of graphite, were used to obtain the correlation between mean size of spheroidal graphite and fatigue strength. (1) 73% pearlite structure had the highest fatigue limitation while 36% pearlite structure had the lowest fatigue limitation among ferrite-pearlite matrix. the increase in spheroidal ratio with increasing fatigue limitation, 90% had the highest, 14.3% increasing more then 10%, distribution range of fatigue life was small in same stress level. (2) (equation omitted) of graphite can be used to predict fatigue limit of Ductile Cast Iron. The Statistical distribution of extreme values of (equation omitted) may be used as a guideline for the control of inclusion size in the steelmaking processes.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 추계 학술논문 발표대회
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• pp.128-129
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• 2016

This study is to categorize the loading of multiple persons on a vertical building elements into three types to test the size of crowd pressure under each loading patterns. The loading patterns is divided under the combination of loading method and loading persons. The loading method is categorized into the method of instantaneous loading of hand on a force plate and the method of continuous loading. The loading persons has been composed of 1~5 persons under the loading patterns. The loading patterns is also divided into lateral loading, longitudinal loading, and agglomeration loading. The subject group has been composed of 12 males in 20s. The load measurement device(size 1800×600×36mm, capacity 20kN, rigidity 28kN/cm) has been designed and manufactured directly. To eliminate the difference of individual, the size of crowd pressure has been converted into the strength to weight ratio (maximum load/weight) for computation. The strength to weight ratio in lateral loading was about 0.91 under instantaneous loading and about 0.47 under continuous loading. The strength to weight ratio in longitudinal loading was about 0.65 under instantaneous loading and about 0.36 under continuous loading. The strength to weight ratio in agglomeration loading was about 0.65 under instantaneous loading and about 0.36 under continuous loading.

• 한국지열·수열에너지학회논문집
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• 제17권3호
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• pp.13-20
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• 2021

The capacity optimization of the heat exchanger of the TEM dehumidifier was performed through numerical analysis. If the ratio of the size of heat exchangers on the cold and hot surfaces of the TEM is not appropriate, the larger the size of the heat exchanger results the lower performance and efficiency. Optimizing the ratio of heat exchangers on the cold surface of TEM can improve the performance and the efficiency compared to when the ratio is 50%. The optimal proportion of cold surface heat exchangers is inversely proportional to the sum of the size of the heat exchangers on the cold and hot surfaces. When the optimum ratio of cold surface heat exchanger was applied, the larger the sum of size of the two heat exchangers results the greater the improvement of the performance and efficiency, compared to when the ratio of cold surface heat exchangers is 50%.

• 대한기계학회논문집
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• 제15권1호
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• pp.252-261
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• 1991

본 연구에서는 2상 횡분류의 평균 유동특성을 비교적 정확히 예측할 수 있는 방법을 제시하는데 있다. 이를 위하여 2상 기체 분류속에 유입되는 자유흐름의 질량 유입을 Keffer와 Baines의 유입함수를 이용하기로 하며, 입자와 기체분류사이의 궤적 이탈을 고려하기로 한다. 이런 모델을 이용하여 2상 횡분류의 분출초기의 입자와 기 체분류의 속도비(particle to gas velocity ratio at the jet exit)가 유동에 미치는 영향을 알아보고자 한다.

• 대한건축학회논문집:구조계
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• 제35권6호
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• pp.111-119
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• 2019

The purpose of this study is to investigate the shear strength of reinforced concrete beam according to beam section size and shear reinforcement ratio. A total of nine specimens were tested and designed concrete compressive strength is 24 MPa. The main variables are shear reinforcement ratio and beam section size fixed with shear span to depth ratio (a/d = 2.5), the tensile reinforcement ratio (${\rho}=0.013$) and width to depth ratio (h/b = 1.5). The test specimens were divided into three series of S1 ($225{\times}338mm$), S2 ($270{\times}405mm$) and S3 ($315{\times}473mm$), respectively. The experimental results show that all specimens represent diagonal tensile failure. For $S^*-1$ specimens (d/s=0), the shear strength decreased by 33% and 46% with increasing the beam effective depth, 26% and 33% for $S^*-2$ specimens (d/s=1.5) and 16% and 20% for $S^*-3$ specimens (d/s=2.0) respectively. As the shear reinforcement ratio increases, the decrease range in shear strength decreases. In other words, this means that as the shear reinforcement ratio increases, the size effect of concrete decreases. In the S1 series, the shear strength increased by 39% and 41% as the shear reinforcement ratio increased, 54% and 76% in the S2 series and 66% and 100% in the S3 series, respectively. As the effective depth of beam increases, the increase range of shear strength increases. This means that the effect of shear reinforcement increases as the beam effective depth increases. As a result of comparing experimental values with theoretical values by standard equation and proposed equation, the ratio by Zsutty and Bazant's equation is 1.30 ~ 1.36 and the ratio by KBC1 and KBC2 is 1.55~.163, respectively. Therefore, Zsutty and Bazant's proposed equation is more likely to reflect the experimental data. The current standard for shear reinforcement ratio (i.e., $S_{max}=d/2$) is expected to be somewhat relaxed because the ratio of experimental values to theoretical values was found to be 1.01 ~ 1.44 for most specimens.