• Title/Summary/Keyword: coefficient-based method

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Shape Optimization of Ball Valve for High Temperature (고온용 볼 밸브의 형상 최적화)

  • Kim, Nam-Hee;Byeon, Ji-Hoon;Lee, Kwon-Hee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.1
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    • pp.15-20
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    • 2017
  • The main purpose of the ball valve ball is to be moved by the rotation of the stem when fully open or completely closed. In this study the heat of the initial model, which used a structure interaction analysis technique, tried to examine the structural safety of the high temperature for the ball valve. In the initial model the stress of the exiting sheet was more than the yield strength. We selected two design shapes with variables of length and thickness for the optimization of the sheet. The Kriging interpolation method was applied to a meta-model-based optimization technique. As a result, it was possible to find a thickness and length for the sheet within the yield strength. This was done by measuring the value of the capacity coefficient of the valve and evaluating the performance of the ball valve.

Effects of Permeation of Thioglycolic Acid with Hair Permanent Wave (두발용 퍼머 약제인 Thioglycolic Acid의 투과 영향)

  • Kim, Yong-Ryul;Yoon, Cheol-Hun;Hwang, Sung-Kwy
    • Journal of the Korean Applied Science and Technology
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    • v.19 no.1
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    • pp.19-24
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    • 2002
  • It is a great role that the character of man or woman could be distinguished by hair on the aspect of ornament. Hair will be support of beautifulness of human being in various permanent wave by many kinds of its drugs. Hair is based upon the skin which enroll the body of high living animals and have multiple membrane structure. This study used rat and the effects of commercial permanent wave products to skin which are composed with thioglycolic acid and bases. Results are as follows. Permanent wave penetrated to 4 hours later with steady state in skins and was not significant changeable after 20hr later. In case of neutralizer with thioglycolic acid lag time and permeability coefficient in healthy skin is 3.38hr and $0.094^{\mu}g/cm^{2}$ ${\cdot}$ hr, it old skin is 3.48hr and 0.129$^{\mu}g/cm^{2}$ ${\cdot}$ hr, and it wounded skin is 4.72hr and $0.158^{\mu}g/cm^{2}$ ${\cdot}$ hr. In conclusion, lag time and permeability coefficient in old skin and wounded skin are faster than healthy skin. In vivo which was studied by general time and method of permanent wave. We notified that fine rinkle and rash of skin were changeable in the case of treating with permanent wave drugs than normal skin. We can see even rash and eruption by the naked eye.

Trend of Occupational Injuries/Diseases in Pakistan: Index Value Analysis of Injured Employed Persons from 2001-02 to 2012-13

  • Abbas, Mohsin
    • Safety and Health at Work
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    • v.6 no.3
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    • pp.218-226
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    • 2015
  • Background: The present study aimed to analyze the index value trends of injured employed persons (IEPs) covered in Pakistan Labour Force Surveys from 2001-02 to 2012-13. Methods: The index value method based on reference years and reference groups was used to analyze the IEP trends in terms of different criteria such as gender, area, employment status, industry types, occupational groups, types of injury, injured body parts, and treatment received. The Pearson correlation coefficient analysis was also performed to investigate the inter-relationship of different occupational variables. Results: The values of IEP increased at the end of the studied year in industry divisions such as agriculture, forestry, hunting, and fishing, followed by in manufacturing and construction industry divisions. People associated with major occupations (such as skilled agricultural and fishery workers) and elementary (unskilled) occupations were found to be at an increasing risk of occupational injuries/diseases with an increasing IEP trend. Types of occupational injuries such as sprain or strain, superficial injury, and dislocation increased during the studied years. Major injured parts of body such as upper limb and lower limb found with increasing trend. Types of treatment received, including hospitalization and no treatment, were found to decrease. Increased IEP can be justified due to inadequate health care facilities, especially in rural areas by increased IEP in terms of gender, areas, received treatment, occupational groups and employment status as results found after Pearson correlation coefficient analysis. Conclusion: The increasing trend in the IEP% of the total employed persons due to agrarian activities shows that there is a need to improve health care setups in rural areas of Pakistan.

Volume Transport on the Texas-Louisiana Continental Shelf

  • Cho Kwang-Woo
    • Fisheries and Aquatic Sciences
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    • v.1 no.1
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    • pp.48-62
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    • 1998
  • Seasonal volume transport on the Texas-Louisiana continental shelf is investigated in terms of objectively fitted transport streamfunction fields based on the current meter data of the Texas­Louisiana Shelf Circulation and Transport Processes Study. Adopted here for the objective mapping is a method employing a two-dimensional truncated Fourier representation of the streamfunction over a domain, with the amplitudes determined by least square fit of the observation. The fitting was done with depth-averaged flow rather than depth-integrated flow to reduce the root-mean-square error. The fitting process filters out $11\%$ of the kinetic energy in the monthly mean transport fields. The shelf-wide pattern of streamfunction fields is similar to that of near-surface velocity fields over the region. The nearshore transport, about 0.1 to 0.3 Sv $(1 Sv= 10^6\;m^3/sec)$, is well correlated with the seasonal signal of along-shelf wind stress. The spring transport is weak compared to other seasons in the inner shelf region. The transport along the shelf break is large and variable. In the southwestern shelf break, transport amounts up to 4.7 Sv, which is associated with the activities of the encroaching of energetic anticyclonic eddies originated in Loop Current of the eastern Gulf of Mexico. The first empirical orthogonal function (EOF) of streamfunction variability contains $67.3\%$ of the variance and shows a simple, shelf-wide, along-shelf pattern of transport. The amplitude evolution of the first EOF is highly correlated (correlation coefficient: 0.88) with the evolution of the along-shelf wind stress. This provides strong evidence that the large portion of seasonal variation of the shelf transport is wind-forced. The second EOF contains $23.7\%$ of the variance and shows eddy activities at the southwestern shelf break. The correlation coefficient between the amplitudes of the second EOF and wind stress is 0.42. We assume that this mode is coupled a periodic inner shelf process with a non-periodic eddy process on the shelf break. The third EOF (accounting for $7.2\% of the variance) shows several cell structures near the shelf break associated with the variability of the Loop Current Eddies. The amplitude time series of the third EOF show little correlation with the along-shelf wind.

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Dynamic Characteristics Analysis of the Cryogenic Nitrogen Injection of Swirl Injector using POD and DMD (POD와 DMD를 이용한 와류형 분사기의 극저온 질소 분무 동적 특성 분석)

  • Kang, Jeongseok;Sung, Hong-Gye;Sohn, Chae Hoon
    • Journal of the Korean Society of Propulsion Engineers
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    • v.21 no.5
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    • pp.1-9
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    • 2017
  • The cryogenic nitrogen spray of a swirl injector has been numerically investigated using three dimensional LES turbulence model to analyze the dynamic characteristics under supercritical condition. To predict the precise nitrogen properties under supercritical condition, SRK equation of state, Chung's method for viscosity and thermal conductivity and Takahashi's correlation based on Fuller's theory for diffusion coefficient are implemented. The complex flow structures due to interaction between flow field and acoustic field are observed inside and outside the injector under supercritical condition. FFT, POD, and DMD techniques are employed to understand the coherent structures. By implementing the FFT, the dominant frequencies are identified inside and outside the injector. The coherent flow structures related to the dominant frequencies are visualized using the POD and DMD techniques. In addition, the DMD provides the damping coefficient which is related with the instability prediction.

A Study on the Determination of Grain Size of Heat-treated Stainless Steel Using Digital Ultrasonic Signal Processing Techniques. (디지털 초음파 신호처리 기법을 이용한 열처리된 스테인레스 스틸의 그레인 크기 결정에 관한 연구)

  • 임내묵;이영석;김성환
    • The Journal of the Acoustical Society of Korea
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    • v.18 no.8
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    • pp.84-93
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    • 1999
  • Determination of grain size of heat-treated stainless steel based fm digital ultrasonic signal processing technique is presented. This techniques consist in evidence accumulation with multiple feature parameters, difference absolute mean value(DAMV), variance(VAR), mean frequency (MEANF), auto regressive model coefficient(ARC) and linear cepstrum coefficient(LCC). Feature parameters were extracted from ultrasonic echo signal of heat-treated metals. It was found that a few parameters might not be sufficient to exactly evaluate the grain size of heat-treated metals. The determination of grain size of heat-treated metals was carried out through the evidence accumulation procedure using the distances measured with reference parameters. A fuzzy mapping function is designed to transform the distances for the application of the evidence accumulation method. In the work presented, heat-treated stainless steel samples with various grain sizes are examined. The processed experimental results supports the feasibility of the grain size determination technique presented.

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Statistical Difference of Production Efficiency in Medicinal Crop Farm (약용작물 재배농가의 생산효율성 통계적 차이에 대한 연구)

  • Choi, Don Woo;Kim, Dong Choon;Lee, Hang Ah;Lim, Cheong Ryong
    • Journal of Korean Society for Quality Management
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    • v.48 no.3
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    • pp.453-462
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    • 2020
  • Purpose::This study aims to analyze the management performance and production efficiency of medicinal crop farmers. Methods: We conducted an empirical survey of medicinal crop farmers and analyzed production efficiency using DEA method. Results: First, The crops that increased the number of farms during 2010 and 2018 were Angelica tenuissima and Salvia miltiorrhiza, which was attributed to higher income per hour than other crops. Second, As for the efficiency of Liriope platyphylla, the average was 0.376, and the coefficient of variation was the lowest, 0.566. Third, Salvia miltiorrhiza and Atractylodes japonica had the highest technical efficiency after Liriope platyphylla, but the variation coefficient was high and the efficiency was relatively high. Fourth, As a result of performing variance analysis to find out the difference of each crops on the value of medicinal crop efficiency, the technical efficiency, pure technical efficiency, and scale efficiency were all statistically significant. Conclusion: Based on the results above, following policy suggestions are offered. First, It is necessary to provide information on crops with high income compared to the input of labor, and to develop labor-saving cultivation technologies for each crop. Second, A stable labor supply system will be needed in rural areas. Third, Efforts should be made to close the technological gap between farmers through a lot of education and consulting for farmers who grow medicinal crops.

An Experimental Study on the Change of Bulking Coefficient of Soils Mixed with Rock Blades (암버력이 혼재된 토사의 토량환산계수 변화에 관한 실험적 연구)

  • Park, Yeong Mog
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.5C
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    • pp.193-198
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    • 2012
  • Field and laboratory tests were performed to investigate the swelling(L value) and shrinkage modulus (C value) of soil and rock mixtures using 2 sites. According to test results, when disturbed soil and rock were mixed with same amount (5:5), the maximum density was achieved and showed 19% and 18% increased at each site comparing with the unit weight of rock only. Since measured L values of mixtures were overestimated about 4 to 11% compare to estimated values based on the conventional method. While C values were underestimated about 13~20% compare to conventional values due to the development of compacting equipments and effective construction management. When rock and soil were mixed in the ratio of 5 to 5, the unit weight of the mixture was higher than that of other mixtures and rock or soil only.

Diabetes Risk Analysis Model with Personalized Food Intake Preference (개인 식품섭취 선호도에 따른 당뇨병 발생 위험도 분석 모델)

  • Jeon, So-Hye;Kim, Nam-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.11
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    • pp.5771-5777
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    • 2013
  • The need of continuous management for diseases came to the fore as a chronic disease has increased, however, research related to personalized food intake analysis are insufficient. In diabetes risk analysis model of this study, food preferences are calculated by Pearson correlation coefficient that is proven method to assess the similarity, and diabetes risk is computed as a Logistic regression that was used in prevalence studies. For the Significance evaluation of this model, it was verified through t-test at 0.05 level of 52 comparison subjects and 52 control subjects. Both groups were significantly independent (p=0.046 <0.05). This model is a new way to personalized health management, through the application to healthcare system based on web and mobile.

Use of Near-Infrared Spectroscopy for Estimating Lignan Glucosides Contents in Intact Sesame Seeds

  • Kim, Kwan-Su;Park, Si-Hyung;Shim, Kang-Bo;Ryu, Su-Noh
    • Journal of Crop Science and Biotechnology
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    • v.10 no.3
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    • pp.185-192
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    • 2007
  • Near-infrared spectroscopy(NIRS) was used to develop a rapid and efficient method to determine lignan glucosides in intact seeds of sesame(Sesamum indicum L.) germplasm accessions in Korea. A total of 93 samples(about 2 g of intact seeds) were scanned in the reflectance mode of a scanning monochromator, and the reference values for lignan glucosides contents were measured by high performance liquid chromatography. Calibration equations for sesaminol triglucoside, sesaminol($1{\rightarrow}2$) diglucoside, sesamolinol diglucoside, sesaminol($1{\rightarrow}6$) diglucoside, and total amount of lignan glucosides were developed using modified partial least square regression with internal cross validation(n=63), which exhibited lower SECV(standard errors of cross-validation), higher $R^2$(coefficient of determination in calibration), and higher 1-VR(ratio of unexplained variance divided by variance) values. Prediction of an external validation set(n=30) showed a significant correlation between reference values and NIRS estimated values based on the SEP(standard error of prediction), $r^2$(coefficient of determination in prediction), and the ratio of standard deviation(SD) of reference data to SEP, as factors used to evaluate the accuracy of equations. The models for each glucoside content had relatively higher values of SD/SEP(C) and $r^2$(more than 2.0 and 0.80, respectively), thereby characterizing those equations as having good quantitative information, while those of sesaminol($1{\rightarrow}2$) diglucoside showing a minor quantity had the lowest SD/SEP(C) and $r^2$ values(1.7 and 0.74, respectively), indicating a poor correlation between reference values and NIRS estimated values. The results indicated that NIRS could be used to rapidly determine lignan glucosides content in sesame seeds in the breeding programs for high quality sesame varieties.

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