• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.261-266
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• 2003

The growth behavior of the transverse crack, which was one of the most dangerous damages of rail defects, was investigated under mode I and mixed mode loading in rail steel. In the case of variable amplitude loading, the fatigue crack growth behavior was discussed using characteristic stress intensity factor ranges ${\Delta}_{rms}$. In addition, characteristic comparative stress intensity factor ranges ${\Delta}_{V,rms}$ was proposed to evaluate the quantitative effects of the variable amplitude under mixed mode loading. As a result, crack growth rate under variable amplitude loading was faster than that under constant amplitude loading.

• 한국안전학회지
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• 제18권1호
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• pp.81-88
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• 2003

Recently, pile foundations were constructed in rough or soft ground than ground of well condition thus it is important that prediction of ultimate bearing capacity and calculation of proper safety factor applied pile foundation design. This study were performed to dynamic loading tests for the thirty two piles at four different construction sites and selected pile at three site were performed to static loading tests and then compare with measured value and value of static and dynamic loading tests. The load-settlement curve form the dynamic loading tests by CAPWAP was very similar to the results obtained from the static load tests. Based on dynamic and static loading tests, the reliability of pile-driving formula were analyzed and then suggested with proper safety factor for prediction of allowable bearing capacity in this paper.

• 한국농공학회지
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• 제45권3호
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• pp.94-102
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• 2003

A hydrologic and water quality monitoring network were established in the Balkan-reservoir watershed, which has 29.79 $km^2$ in size, to analyze the characteristics of pollutant loading from an agricultural small watershed. Soil type, land use, hydrologic soil group, population and livestock were also surveyed to make clear the pollutant sources and to calculate the pollutant loadings by the unit loading factor method which was proposed by the Ministry of Environment. From the 5-year hydrologic monitoring results, sub-watersheds located in the upstream of the reservoirs showed higher average runoff ratio. The calculated daily pollutant loadings by the unit loading factor method from HP#2 sub-watershed in the downstream of Balkan reservoir, were much greater than observed.

• The Journal of Asian Finance, Economics and Business
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• 제8권5호
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• pp.1139-1145
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• 2021

This study is aimed at developing a measurement instrument for the superior product development program of Deli Serdang cassava, Indonesia. This research population is the target population of Deli Serdang Micro, Small and Medium-sized Enterprises (MSMEs) which produces cassava. The sample was randomly selected and consisted of 300 MSMEs. The study method is research and development with confirmatory factor analysis using Amos software. The data collection technique was a questionnaire. Study results used the maximum likelihood method which showed that the validity and reliability instruments met the ideal loading factor value > 0.5 and a significance value of p (0.000). The model built also meets the fit criteria based on the Goodness of Fit Model Standard. All instruments are presented to build and measure the superior cassava product development program by Deli Serdang MSMEs. This superior product development program comprises (1) economic contribution (with a loading factor value of 0.76) (2) social aspects (with a loading factor value of 0.76) (3) cultural aspects (with a loading factor value of 0.99) and (4) institutional (with a loading factor value of 0.87). This result means that all instruments have proven construct validity.

• 한국환경보건학회지
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• 제15권2호
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• pp.51-58
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• 1989

In order to estimate unit loading factors of N, and P for controlling eutrophication of Youngsan lake. This study was performed in 4 kinds of pollutant sources from domestic sewage, industrial waste water, livestock stall waste water and drainage of agricultural area during the period from april to october 1988. These results were as follows: 1. The sewage flow for domestic waste water was 191.2 l/capita, day and that of the gray and toilet waste water among the domestic waste water were shown 152.9 l/capita, day(80%) and 38.3 l/capita, day(20%), respectively. 2. The unit loading factor total nitrogen(T-N) for domestic waste water was 7.582g/capita, day, and that of the gray and toilet waste water among the domestic waste water were 1.826g/ capita, day(24.1%) and 5.756g/capita, day(75.9%), respectively. The other hand, the unit loading factors of total phosphorus(T-P) for domestic waste water was 0.925g/capita, day, and that of gray and toilet waste water among the domestic waste water were 0.470g/capita, day(50.8%) and 0.455g/capita, day(49.2%), respectively. 3. In offering Price per million won, the T-P loading factor for drinking manufacture, confectionery manufacture, beer-manufacture and fibre manufacture in the industrial pollutant sources estimate to be 0.350g/day, 0.099g/day, 32.351g/day and 1.536g/day, while T-N loading factor about them in the industrial pollutant sources estimate to be 4.117g/day, 2.414g/day, 106.726g/day and 60.504g/day, respectively. 4. The T-P loading factor according to wash-water of milch cow and pig were 6.735g/day and 18.526g/day, in case of T-N they were 42.397g/day and 27.226g/day, respectively. 5. The T-P loading factor for pollutants drainage in the Paddy fields, fields and forests area were 0.082g/are, day, 0.014g/are, day and 0.002g/are, day, and the T-N loading factor were 0.309g/are, day, 0.158g/are, day and 0.064g/are, day, respectively. The diffrent of the loading factor for pollutants discharges in the agricultural area were resulted from the rainful intensity, the rainful, the amount of fertilization manure, and etc.

• 한국자동차공학회논문집
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• 제20권1호
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• pp.141-146
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• 2012

Aluminum alloys have been used with various thicknesses suitable for light weight of structure. It is known that the thickness effect of material is an important factor affecting fatigue crack propagation under constant fatigue stress condition. In this work, we presented the behavior of fatigue crack propagation in thin plate compared to thick plate Al 2024-T3 alloy with referred thickness effect in a correlative equation determined by the shape factor and the loading factor. We chose two factors that are used in the correlative equation with considering that the experiments were carried out under a constant fatigue stress condition. The thickness ratio of thin plate compared to thick plate and the equivalent effective stress intensity factor ratio depending on thickness were chosen as shape and loading factors. A correlative equation is utilized to determine the equivalent effective stress intensity factor range of thin plate and identify the degree of increasing phenomenon of fatigue life in thin plate compared to thick plate.

• 대한기계학회논문집
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• 제18권12호
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• pp.3219-3226
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• 1994

A model is constructed to evaluate the stress intensity factors for a center crack subjected to polynomial anti-symmetric loading in a layered material. A Fredholm integral equation is derived by Fourier integral transform method. The integral equation is numerically analyzed to evaluate the effects of the ratios of shear modulus, Poisson's ratio and crack length to layer thickness as well as the number of layers on the stress intensity factor. The stress intensity factors are approached to constant values as the number of layers increase and decrease as the polynomial power of the loading increase. In case of the E-glass/Epoxy composite, dimensionless stress intensity factor is affected by cracked-resin layer thickness.

• Steel and Composite Structures
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• 제18권1호
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• pp.71-90
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• 2015

Axial compression tests have been carried out on 18 rectangular concrete-filled cold-formed steel tubular (CFST) columns with the aim of investigating the axial behaviour of rectangular CFST columns under different loading methods (steel loaded-first and full-section loaded methods). The influence of different loading methods on the ultimate strength of the specimens was compared and the development of Poisson's Ratio as it responds to an increasing load was reported and analysed. Then, the relationship between the constraining factor and the strength index, and the relationship between the constraining factor and ductility index of the specimens, were both discussed. Furthermore, the test results of the full-section loaded specimens were compared with five international code predicted values, and an equation was derived to predict the axial carrying capacity for rectangular CFST columns with a steel loaded-first loading method.

• 대한기계학회논문집A
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• 제22권3호
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• pp.569-578
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• 1998

The mode I and II stress intensity factors have been calculated theoretically for the cracked plate reinforced with a plate by symmetric spot welding under remote mixed mode loading. This is the extension of authors' previous work for the reinforced cracked plate under remote normal stress. Regardless of loading types, the reinforcement effect gets better as one joining spot is closer to the crack tip and the others are closer to the crack surface, and optimum number of the joining spots can be existed. For the present model, the remote loading parallel to crack surface produces the mode I stress intensity factor.

• 한국해양공학회지
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• 제8권2호
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• pp.115-123
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• 1994

Under variable amplitude loading conditions, retardation or accelerated condition of fatigue crack growth occurs with every cycle, Because fatigue crack growth behavior varied depend on load time history. The modeling of stress amplitude with storm loading acted to ships and offshore structures applied this paper. The crack closure behavior examine by recording the variation in load-strain relationship. By taking process mentioned above, fatigue crack growth rate, crack length, stress intensity factor, and crack closure stress intensity factor were obtained from the stress cycles of each type of storm ; A(6m), B(7m), C(8m), D(9m), E(11m) and F(15m) which was wave height. It showed that the good agreement with between the experiment results and simulation of storm loads. So this estimated method of crack propagtion rate gives a good criterion for the safe design of vessels and marine structure.