• 품질경영학회지
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• 제21권2호
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• pp.140-155
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• 1993

The characteristics of $I_{\lambda}$-optimality, one of the linear criteria suggested by Fedorov (1972) are investigated with respect to the D-and heteroscedastic G-optimality in case of non-constant variance function. Though having limited results obtained from simple models, we may conclude that $I_{\lambda}$-optimality is sometimes preferred to the heteroscedastic G-optimality suggested newly bv Wong and Cook (1992) in the sense that the experimenter's belief in weighting function exists in $I_{\lambda}$-optimality criterion, not to mention its computational simplicity.

• 품질경영학회지
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• 제16권2호
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• pp.18-33
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• 1988

A new diagnostic statistic for detecting outliers and influential observations in linear models is suggested and studied in this paper. The proposed statistic is a weighted sum of two measures ; one is for detecting outliers and the other is for detecting influential ovservations. The merit of this statistic is that it is possible to distinguish outliers from influential observations. This statistic can be used for not only regression models but also factorial design models. A Monte Carlo simulation study is reported to suggest critical values for detecting outliers and influential observations for simple regression models when the number of observations is 11. 21, 31, 41 or 51.

• Preventive Nutrition and Food Science
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• 제4권2호
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• pp.85-87
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• 1999

A simple and rapid method to estimate the viscosity of chitosan using laboratory pipettes was developed. The voscosities of nine different chitosan samples, prepared ini 1 % acetic acid at a 1% concentration , were measured with a standard viscometer. Prior to measurement of flow time of 1% chitosan solution with a pipette, twelve pipettes were assorted into three groups with flow times of 4, 5 and 6 sec after measuring passage of 9 ml of 1% acetic acid througth a 10 ml pipette. With each group of pipettes. flow time of 1% chitosan solution was determined by measuring the delivery time of 5 ml of the 10ml solution through a 10 ml pipette. Results of regression analyses revealed high linear relationship(R2=0.9812, 0.9663, and 0.9754) between viscosities calculated with a viscometer and flow times measured with 4, 5 or 6 sec group pipettes. The viscosity of chitosan could be readily and accurately estimated from these linear regression equation by measuring flow times based on pipette delivery.

• 한국연초학회지
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• 제6권1호
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• pp.51-62
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• 1984

The chemical components of non-blended and blended cigarettes and their smoke have been analyzed to investigate the correlation between them. Some regression of linear equations were obtained based on the simple correlation data(r), for the various smoke components such as tar, nicotine, nitrogen dioxide, steam volatile phenols, formaldehyde, acetaldehyde, acrolein and hydrogen cyanide. Chi-square tests were carried out to observe the probabilities of the values estimated by the regression of linear equations. The probabilities of the greater values were 0.900-0.999 to tar, nicotine, formaldehyde, acetal dehyde, acrolein, steam volatile phenols, nitrogen dioxide and hydrogen cyanide of the non-blended cigarettes, and 0.900-0.999 to tar, nicotine, nitrogen dioxide, steam volatile phenols and static burning rate (SBR) of the blended cigarettes.

• 자동차안전학회지
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• 제14권1호
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• pp.62-67
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• 2022

This study is to construct the simple estimating model for the HIC15 of the driver dummy using the frontal impact test results. Test results of 9 vehicles of Hyundai Sonata from the MY2002~MY2020 USNCAP are utilized for constructing the linear regression model. The average accelerations extracted from the vehicle crash pulses are handled as the main factors. The average accelerations of 10 ms interval within 0~100 ms are calculated from the crash pulse data of 9 vehicles. The present estimating model of the HIC15 using the average accelerations of 10 ms interval in the 0~80 ms range shows good agreement with the tested value within 2.4% maximum error.

• 한국지리정보학회지
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• 제20권4호
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• pp.65-76
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• 2017

본 연구는 범죄와 환경과의 관계가 밀접한 영향을 미친다는 전제하에 범죄억제를 위한 정책수립 및 설계를 위한 대안마련의 사전단계로 범죄위험지역 분석과 요인, 공간적 특성이 반영된 예측모델을 제시하는 것을 주요 목적으로 수행하였다. 연구의 분석결과, H구 전체 지역에 범죄가 균등하게 분포하였을 경우와 대비하여 약 1/4 수준으로 범죄발생지역은 군집성을 나타내고 있었으며 주로 H 해수욕장 배후 상업지역에서 특정범죄(강간, 절도, 폭력)는 강한 핫스팟을 나타내었다. 결과적으로 독립변수와 종속변수의 공간적 상관관계를 고려하는 지리가중회귀모형을 이용함으로써 보다 효과적으로 적용할 수 있음을 알 수 있었다. 이러한 결과는 다중선형회귀 모형의 결과에서와 같이 연구지역 내 폐공가수가 종속변수와 단순히 부적의 관계를 가지는 것이 아니라, 지역에 따라 종속변수에 서로 다른 영향을 미치는 것을 알 수 있다.

• 한국응급구조학회지
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• 제14권3호
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• pp.5-11
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• 2010

Purpose: This study was to clarify correlation between en route distance and role time on call received hours. Methods: Data on en route distance(dependent variable), role time(independent variable) from 387 prehospital care reports documented by EMS in Kyonggi Provincial Fire and Disaster Headquarters and Seoul Metropolitan Fire and Disaster Department between 21 and 10 June 2010 were randomly chosen for simple regression analysis using Windows SPSS 12. OK. This analysis was conducted nine times on unit hour divided to eight call received and overall. Results: Statistically significant regression equations( Y=2.414+1.206X for 09:00~11:59, Y=3.753+.662X for 12:00~14:59, Y=2.215+1.458X for 15:00~17:59, Y=2.600+.822X for 21:00~23:59, Y=5. 445+.263X for overall) were derieved from the data. Conclusion: These equations having linear relationship may be utilized as a method for system status management to effectively response to emergency call.

• 한국작물학회지
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• 제45권1호
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• pp.14-19
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• 2000

In order to develop an appropriate cultural practice for a newly bred 2-rowed, waxy, naked barley cultivar 'Duwonchapssalbori' in the southern region, 2 varieties, 3 seeding dates, 4 seeding rates were designed with 2 replications. The heading and maturity dates of 'Duwonchapssalbori' were' earlier than 'Saessalbori by 2-5 and 4 days, respectively. Culm length of 'Duwonchapssalbori' was 60 to 66cm with lodging resistance. Grain yields of both varieties were 4.28-4.33 ton/ha in the plot of Oct. 20 seeding, 4.11-4.18 ton in the plot of Oct. 28 seeding, and 3.7-13.89 ton/ha in the Nov. 5 seeding. Grain yield with different seeding rates highly significantly fitted with secondary polynomial equations in the plots of Oct. 20 and Oct. 28 seedings ($R^2$=0.84-0.85), showing the greatest yield with seeding rate of 140kg per ha. However, the grain yield with various seeding rates in the plot of Nov. 5 seeding showed simple linear regression ($R^2$=0.71), showing the seeding rate over 160kg in the case of later seeding to be optimal. Number of spikes per $m^2$ significantly contributed to grain yield, and fitted to simple linear regression ($R^2$=0.881-0.891), suggesting that plenty of early stands should be established at early seedling stage for high grain yield. Young spikes of 'Duwonchapssalbori' in the plot of Oct. 20 seeding elongated with linear increments since Feb. 10 (6.7mm), and showed rapid increment since March 7 (15.1mm). However, elongation of young spikes of 'Saessalbori' began from March 15 with slow increments. From these studies, the optimum seeding date and seeding rate in 'Duwonchapssalbori' were Oct. 20-28 and 140kg per ha for high grain yield in the southern regions.

• Geomechanics and Engineering
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• 제34권6호
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• pp.697-726
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• 2023

Brittleness as an important property of rock plays a crucial role both in the failure process of intact rock and rock mass response to excavation in engineering geological and geotechnical projects. Generally, rock brittleness indices are calculated from the mechanical properties of rocks such as uniaxial compressive strength, tensile strength and modulus of elasticity. These properties are generally determined from complicated, expensive and time-consuming tests in laboratory. For this reason, in the present research, an attempt has been made to predict the rock brittleness indices from simple, inexpensive, and quick laboratory test results namely dry unit weight, porosity, slake-durability index, P-wave velocity, Schmidt rebound hardness, and point load strength index using multiple linear regression, exponential regression, support vector machine (SVM) with various kernels, generating fuzzy inference system, and regression tree ensemble (RTE) with boosting framework. So, this could be considered as an innovation for the present research. For this purpose, the number of 39 rock samples including five igneous, twenty-six sedimentary, and eight metamorphic were collected from different regions of Iran. Mineralogical, physical and mechanical properties as well as five well known rock brittleness indices (i.e., B₁, B₂, B₃, B₄, and B₅) were measured for the selected rock samples before application of the above-mentioned machine learning techniques. The performance of the developed models was evaluated based on several statistical metrics such as mean square error, relative absolute error, root relative absolute error, determination coefficients, variance account for, mean absolute percentage error and standard deviation of the error. The comparison of the obtained results revealed that among the studied methods, SVM is the most suitable one for predicting B₁, B₂ and B₅, while RTE predicts B₃ and B₄ better than other methods.

• 한국작물학회지
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• 제45권5호
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• pp.322-327
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• 2000

For the stable production of high quality tea, the freezing resistance is a very important character. Most of the farmers have planted out-pollinated seeds that are not genetically pure. So, with small sample, a quick and simple method is required to test freezing resistance of lots of germ-plasm and early generation of hybrids. The absorbances(A530 nm) of TTC reduction solution at -5$^{\circ}C$ were positively correlated with resistance to photoinhibition of PSII in 6 hour photoinhibitory treatments, being significantly fitted by simple linear regression ($R^2$=${0.64}^{**}$). Chlorophyll fluorescence measured by Fv/Fm was found to be very useful in evaluating the relative levels of freezing resistance in tea.