• Journal of Forest and Environmental Science
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• v.10 no.1
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• pp.49-56
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• 1994

This study was carried out to estimate forest road elongation coefficients for providing the basic information of forest road construction. As the results, road elongation coefficients were calculated 0.33 less than 5% of road gradient, 0.39 between the gradient of 6% and 10%, 0.50 between the gradient of 11% and 15%, 0.58 between the gradient of 16% and 20%, and 0.60 greater than the gradient of 20%.

• Journal of Korean Society of Forest Science
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• v.84 no.4
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• pp.517-524
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• 1995

This study was conducted to investigate the characteristics of the road alignment, correlations among evaluation factors of the alingment, and the relationships between the evaluation factors and terrain factors for the forest road of five National Forest Offices. The results were as follows : 1. The elongation coefficients(${\eta}$) of forest road in Kangnung and Wonju National Forest Office were ranged 0.3~0.5, and those of Andong, Namwon, and Kongju National Forest Offices were ranged 0.2~0.3 in straight line of 100m, 200m, and 300m. 2. Three different types of plane alignment were identified for Kangnung and Wonju National Forest Offices, Namwon and Kongju National Forest Offices, Andong National Forest Office. However, longitudinal alignment for five National Forest Offices tended to be similar conditions. 3. Low correlation coefficients were calculated in the relation between elongation coefficients(${\eta}$) and evaluation factors of plane alignment(curve length ratio(%), sum of inverse number of each curve radius(m/km), and sum of each intersection angle($^{\circ}/km$)) for three straight lines. On the contrary, high correlation coefficients were obtained among the relations of curve length ratio(%), sum of inverse number of each curve radius(m/km), and sum of each intersection angle($^{\circ}/km$). 4. Slope(%) were closely correlated with plane alignment, and so were the relationships between frequency of valleys and streams(No./km) and elongation coefficients(${\eta}$) of forest road.

• Bulletin of the Korean Chemical Society
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• v.28 no.10
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• pp.1697-1704
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• 2007

We present results for transport properties of diatomic fluids by isothermal-isobaric (NpT) equilibrium molecular dynamics (EMD) simulations using Green-Kubo and Einstein formulas. As the molecular elongation of diatomic molecules increases from the spherical monatomic molecule, the diffusion coefficient increases, indicating that longish shape molecules diffuse more than spherical molecules, and the rotational diffusion coefficients are almost the same in the statistical error since random rotation decreases. The calculated translational viscosity decreases with the molecular elongation of diatomic molecule within statistical error bar, while the rotational viscosity increases. The total thermal conductivity decreases as the molecular elongation increases. This result of thermal conductivity for diatomic molecules by EMD simulations is again inconsistent with the earlier results of those by non-equilibrium molecular dynamics (NEMD) simulations even though the missing terms related to rotational degree of freedom into the Green-Kubo and Einstein formulas with regard to the calculation of thermal conductivity for molecular fluids are included.

• Steel and Composite Structures
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• v.2 no.4
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• pp.247-258
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• 2002

The high-temperature material properties of steel are very important to the fire resistance analysis of high-strength bolt connections. This paper reports on the results of the experimental studies on the high-temperature properties of 20 MnTiB steel which is widely used in high-strength bolts, and the friction coefficient of 16Mn steel plates at elevated temperature which is a necessary parameter for bolted frictional connection analysis. The test data includes yield strength, limit strength, modulus of elasticity, elongation and expansion coefficient of 20MnTiB steel at elevated temperature, and the friction coefficients between two 16Mn steel plates under elevated temperatures and after cooling. Based on the data from the tests, the mathematical models for predicting the mechanical properties of 20MnTiB steel and friction coefficients of 16Mn steel plates have been established.

• Journal of Sericultural and Entomological Science
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• no.11
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• pp.73-80
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• 1970

This study was carried out in order to investigate the correlation among test items of export raw silk. The results obtained from the study are summarized as follows. 1. The highest correlation was between evenness and low evenness in case of the filaments made of autumn cocoons and the coefficient of correlation was 0.854. 2. Among following items, viz.; evenness and cleanness, neatness and low neatness and elongation and cohesion, the correlation phisically was not acknowledged, but the coefficients of correlation were high figures. 3. Poor correlation existed between following items, viz.; size deviation and maximum deviation, evenness and low evenness, neatness and low neatness, cleanness and low neatness. 4. It is considered that the high correlation exists between tenacity and elongation, but in this study the correlation existed among some items. 5. In this study it is a new fact that the correlation between neatness and cohesion as well as low neatness and tenacity existed enough highly. 6. As a conclusion the independence of ten items tested at present was acknowledged.

• Ecology and Resilient Infrastructure
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• v.5 no.1
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• pp.1-10
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• 2018

We examined the effect of simultaneous application of phosphorus (P) and iron (Fe) on the phytotoxicity of lettuce in arsenic (As) contaminated soil using response surface methodology (RSM). To stabilize As and supply nutrient into soil, Fe and P were treated, respectively. Water soluble As and P was decreased by Fe application but increased by P application. Through phytotoxicity test, the result showed that only the addition of P affected lettuce root elongation even though both P and Fe were added. The correlation coefficients between root elongation and other indices indicated that the As content in the roots seemed to be the main reason that root growth was impeded. We could verify that the former result was not a passing phenomenon and Fe was necessarily needed to protect secondary pollution by exclusive usage of P fertilizer.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.1
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• pp.68-77
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• 1992

The present experiments were conducted to investigate the variability of hypocotyl elongation among the major soybean varieties by checking several conditions. The results obtained are summarized as follows. The rate of hypocotyl elongation is the highest during the day from 3.0 to 3.5 after seeding. It follows that it may be reasonable to evaluate the hypocotyl elongation of soybean seeds by comparison of hypocotyl length. And the tested 15 major cultivars could be classified as follow ; long ; Eunhakong, Janggyungkong and Bokwangkong, medium ; Namhekong, Dangyung-kong, Danyubkong, Milyangkong, Dugyukong, Paldalkong, Mangunjoseng, Namchunkong and Seal kong, short ; Gwanggyo, Begunkong and Jangbegkong. The hypocotyl elongation in small seed is longer than large seed. Correlation coefficients(r) for the relationships between 100 seed weight and hypocotyl elongation is -0.2506$^{**}$. As the rising temperature, the hypocotyl length is elongated, and longest at the range of 30 to 35$^{\circ}C$. The effects G $A_3$ hastened the hypocotyl elongation of soybean seed, and ABA, Kinetin and BA inhibit it, and that of those in short hypocotyl cultivars are higher than long hypocotyl cultivars. Hypocotyl length of long hypocotyl cultivars are longer than that of short hypocotyl cultivars under high temperature pre -treatment.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5A
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• pp.487-494
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• 2009

Friction coefficients of the prestressing tendon are the basic information required to control the prestressing force introduced to PSC structure during jacking. However, the friction coefficients show considerable differences depending on the specifications, causing much confusion to designers. In this study, the ranges of the friction coefficients presented in domestic and foreign specifications are compared together to clarify the differences. Then, a procedure is proposed that can be used to estimate the wobble and curvature friction coefficients from field data such as elongation and prestressing force and from theory related to the friction. The procedure is applied to various tendon profiles of several PSC bridges constructed by ILM, FCM and MSS. The resulting values are compared with those presented in some specifications and assumed in jacking and a reasonable range of the friction coefficient is discussed. Lift-off tests are also performed in some bridges to further verify the results. The resulting wobble friction coefficients are not as small as those presented in AASHTO specifications but range from the lower limit to mid point of domestic specifications, while the curvature friction coefficients approach or slightly exceed the upper limit.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.25-28
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• 2004

A fracture was generated by change of clearance and deterioration of material properties on the sheet metal through temperature. This paper describes the results of a prediction about the temperature of the sheet metal during continuous stamping process, because the temperature increase of the sheet metal has a detrimental effect on formability. To analyze the temperature increase of the sheet metal during continuous stamping process, tensile and friction tests were performed from room temperature to 300$^{\circ}C$ at warm condition in this study. As temperature increase, tensile strength, elongation, strain hardening exponent and anisotropy coefficient for each specimens were decreased. On the other hand, friction coefficients were increased. From the FE-simulation results, temperature upward tendency was identified on dies and sheet metal. These observations are rationalized on the basis of the material properties, friction coefficient vs. temperature relationship for the sheet.

• Fibers and Polymers
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• v.7 no.1
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• pp.8-11
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• 2006

It has been reported for several decades that microbes, which naturally contaminate cotton fibres during crop growth and subsequent storage can have an adverse effect on the structural quality of cotton lint. Although several studies have analysed the relationship between numbers of Gram-negative bacteria or bacterial endotoxin and particular physical properties, these studies have been limited to cotton from the United States, and the possible effects of fungal contamination have not been examined in detail. This study quantified the Gram-negative bacteria and fungal cells, as well as measuring concentrations of bacterial endotoxin and fungal glucan, on cotton lint samples from international sources. Spearman's rank correlation coefficients calculated between these results and quality data analysed by an automated testing instrument revealed several significant correlations. Findings included inverse correlations between the biological contamination parameters and fibre elongation, micronaire and reflectance. The possible causes and implications of these findings were also discussed.