• Title/Summary/Keyword: trimming

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Asymptotically Efficient L-Estimation for Regression Slope When Trimming is Given (절사가 주어질때 회귀기울기의 점근적 최량 L-추정법)

  • Sang Moon Han
    • The Korean Journal of Applied Statistics
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    • v.7 no.2
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    • pp.173-182
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    • 1994
  • By applying slope estimator under the arbitrary error distributions proposed by Han(1993), if we define regression quantiles to give upper and lower trimming part and blocks of data, we show the proposed slope estimator has asymptotically efficient slope estimator when the number of regression quantiles to from blocks of data goes to sufficiently large.

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Evaluation of the Homogeneity of Korean Diagnosis Related Groups (한국형진단명기준환자군 분류체계의 동질성 평가)

  • Kim, Hyung Seon;Lee, Sun Hee;Nam, Chung Mo
    • Health Policy and Management
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    • v.23 no.1
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    • pp.44-51
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    • 2013
  • Background: This study designed to evaluate the homogeneity of Korean diagnosis related group (KDRG) version 3.4 classification system. Methods: The total 5,921,873 claims data submitted to the Health Insurance Review and Assessment Service during 2010 were used. Both coefficient of variation (CV) and reduction in variance of cost were measured for evaluation. This analysis was divided into before and after trimming outliers at the level of adjacent DRG (ADRG), aged ADRG (AADRG) split by age, and DRG split by complication and comorbidity. Results: At the each three level of ADRG, AADRG, and DRG, there were 38.9%, 38.7%, and 30.0% of which had a CV > 100% in the untrimmed data and there were 1.4%, 1.4%, and 1.9% in the trimmed one. Before trimming outliers, ADRGs explained 52.5% of the variability in resource use, AADRGs did 53.1% and DRGs did 57.1%. The additional explanatory power by age and comorbidity and complication (CC) split were 0.6%p and 4.6%p for each, which were statistically significant. After trimming outliers, ADRGs explained 75.2% of the variability in resource use, AADRGs did 75.6%, and DRGs did 77.1%. The additional explanatory power were 0.4%p and 2.0%p for each, which were statistically significant too. Conclusion: The results demonstrated that KDRG showed high homogeneity within groups and performance after trimming outliers. But there were DRGs CV > 100% after age or CC split and the most contributing factor to high performance of KDRG was the ADRG rather than age or CC split. Therefore, it is recommended that the efforts for improving clinical homogeneity of KDRG such as review of the hierarchical structure of classification systems and classification variables.

A High-efficiency Trim Method for CFD Numerical Calculation of Helicopter Rotors

  • Ye, Zhou;Xu, Guo-hua;Shi, Yong-jie;Xia, Run-ze
    • International Journal of Aeronautical and Space Sciences
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    • v.18 no.2
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    • pp.186-196
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    • 2017
  • In order to resolve the trimming difficulty in rotor CFD calculations, a high-efficiency and improved "delta trim method" is established to compute the blade control settings that are necessary to identify the blade motion. In this method, a simplified model which combines the blade element theory and different inflow models is employed to calculate the control settings according to the target aerodynamic forces, then it is coupled into a CFD solver with unsteady Navier-Stokes equations by the delta methodology, which makes the control settings and aerodynamics calculated and updated in the meantime at every trim cycle. Different from the previous work, the current research combines the inflow model based on prescribed wake theory. Using the method established, the control settings and aerodynamic characteristics of Helishape 7A, AH-1G and Caradonna-Tung rotors are calculated. The influence of different inflow models on trimming calculations is analyzed and the computational efficiency of the current "delta trim method" is compared with that of the "CFD-based trim method". Furthermore, for the sake of improving the calculation efficiency, a novel acceleration factor method is introduced to accelerate the trimming process. From the numerical cases, it is demonstrated that the current "delta trim method" has higher computational efficiency than "CFD-based trim method" in both hover and forward flight, and up to 70% of the amount of calculation can be saved by current "delta trim method" which turns out to be satisfactory for engineering applications. In addition, the proposed acceleration factor shows a good ability to accelerate the trim procedure, and the prescribed wake inflow model is always of better stability than other simple inflow models whether the acceleration factor is utilized in trimming calculations.

Effect of Manufacturing Parameters on Characteristic of Thin Film Resistor (박막저항기 특성에 미치는 제조 공정 인자의 영향)

  • Park Hyun-Sik;Yu Yun-Seop
    • Journal of the Microelectronics and Packaging Society
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    • v.12 no.1 s.34
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    • pp.1-7
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    • 2005
  • The effect of trimming process to adjust accurate resistance of a thin-film resistor was studied with respect to low temperature coefficient of resistance(TCR) and high precision. The characteristics of a thin-film resistor fabricated by sputtering were investigated depending on trimming condition and annealing temperature. Measured results showed that the characteristic of a thin-film resistor was degraded with increased trimming speed. However, an average resistance deviation and a TCR were improved to $0.26\%$ and 52.77[ppm/K], respectively, through annealing treatment. Also, thin-film resistors with 1 k$\Omega$ and 10k$\Omega$ showed better performance compared to a resistor with 100k$\Omega$. The Optimal trimming speed and annealing temperature were 20mm/sec and 539K, respectively, and under this optimal condition, a thin-film resistor with an average resistance deviation of $0.31\%$ and a TCR of below 10[ppm/K] was obtained.

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A study on nail art design based on the application of trimmings in the 18th century women's clothes - Focus on braids, laces, and ribbons - (18세기 여성 의복에 나타난 트리밍을 응용한 네일아트 디자인 연구 - 브레이드, 레이스, 리본을 중심으로 -)

  • Cho, Han-Sol;Rhee, Young-Ju
    • Journal of the Korea Fashion and Costume Design Association
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    • v.21 no.4
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    • pp.127-137
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    • 2019
  • Nail art, which has been popularized recently, has increased convenience in the direction of nail art design harmonized with clothing and the increased interest and usage of nail art decoration. This study set out to propose practical planar and three-dimensional nail art designs in harmony with modern clothes by applying trimmings common in 18th century women's clothing, which used a variety of attachable decorations. As for the methodology, the investigator examined theories in previous studies, literature, and analyzed the types of trimming in female portraits from the 18th century at the museum at the Palace of Versailles in France. Planar and three-dimensional nail art designs were created for each of the top three trimming types- braids, laces, and ribbons, which were identified through analysis. The study applied the trimmings of the 18th century women's clothes to nail art design and had the following results: First, the top three trimming types were identified based on the analysis of the 18th century portraits. They were then used as motifs in the production of planar and three-dimensional nail art designs. The results show that the motifs of the clothes trimmings were fit for and had practical possibilities for expression in nail art designs. Secondly, diversity and the expansion of ideas in the study of nail art design were promoted. In addition, elements were increased to have mutually complementary effects with clothes. Finally, the study made various attempts at nail design methods by adopting a range of nail art expression techniques including hand painting, 2D & 3D art techniques, and using planar and three-dimensional nail decorations, thus proposing a positive direction for the organization of a curriculum to make use of 18th century women's clothing motifs in nail art education.

A study on the characterization of shear surface according to shear rate and shear mechanism in high temperature shear process of boron steel (보론강 고온전단공정에서 전단속도 및 메커니즘에 따른 전단면 특성 파악에 관한 연구)

  • Jeon, Yong-Jun;Choi, Hyun-Seok;Lee, Hwan-Ju;Kim, Dong-Earn
    • Design & Manufacturing
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    • v.11 no.2
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    • pp.37-41
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    • 2017
  • With light vehicle weight gradually becoming ever more importance due to tightened exhaust gas regulations, hot-stamping processing using boron alloyed steel is being applied more and more by major automobile OEMs since process assures both moldability and a high strength of 1.5 GPa. Although laser trimming is generally applied to the post-processing of the hot-stamped process with high strength, there have been many studies of in-die hot trimming using shear dies during the quenching of material in order to shorten processing times. As such, this study investigated the effects of the Shear rate and Shear mechanism on shear processes during the quenching process of hot-stamping material. In case of pad variable, padding force is very weak compared with shear force, so it does not affect the shear surface. In case of shear rate, the higher the shear at high temperatures and the higher the friction effect. As a result the rollover and the fracture distribution decreased, and the burnish distribution increased. Therefore, it is considered that the shear quality is guaranteed when high shear rate is applied in high temperature shear process.

Machine-printed Numeral Recognition using Weighted Template Matching with Chain Code Trimming (체인 코드 트리밍과 가중 원형 정합을 이용한 인쇄체 숫자 인식)

  • Jung, Min-Chul
    • Journal of Intelligence and Information Systems
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    • v.13 no.4
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    • pp.35-44
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    • 2007
  • This paper proposes a new method of weighted template matching for machine-printed numeral recognition. The proposed weighted template matching, which emphasizes the feature of a pattern using adaptive Hamming distance on local feature areas, improves the recognition rate while template matching processes an input image as one global feature. Template matching is vulnerable to random noises that generate ragged outlines of a pattern when it is binarized. This paper offers a method of chain code trimming in order to remove ragged outlines. The method corrects specific chain codes within the chain codes of the inner and the outer contour of a pattern. The experiment compares confusion matrices of both the template matching and the proposed weighted template matching with chain code trimming. The result shows that the proposed method improves fairly the recognition rate of the machine-printed numerals.

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Study on the Shear Characteristics by using the Hot Mechanical Piercing during the Hot Stamping Process (열간 기계적 피어싱을 이용한 핫스탬핑 전단특성 연구)

  • K. J. Park;J. M. Park;J. Y. Kong;J. Y. Kim;S. C. Yoon;J. S. Hyun;Y. D. Jung
    • Transactions of Materials Processing
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    • v.32 no.2
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    • pp.81-86
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    • 2023
  • The hot stamping process is widely used for high strength of vehicle parts, with heating 900 ℃ or higher in a furnace and in-die quenching to achieve strength above 1.5 GPa of the quenchable boron alloyed steel 22MnB5. First of all, the hot stamping process consisted of heating, forming, quenching and trimming. In the trimming process case, the laser method has been conventionally adopted. For laser trimming process, it has the problems pertaining to low productivity and high cost while the hot stamping process, accordingly the trimming process need to investigate the research for alternative method. In order to overcome these issues, many research groups have studied the mechanical trim solution on the hot stamped parts at high temperature. In this study, the mechanical piercing was performed during the hot stamping process at the high temperature for overcome the disadvantages of laser cutting. Also, the process parameters such as piercing time after die closing, clearances of between die and punch were controlled for obtaining the reasonable shear characteristics.