• Transactions of The Korea Fluid Power Systems Society
• /
• v.3 no.3
• /
• pp.20-24
• /
• 2006

Air balancer is a conveyance cargo-handling machine, used in assembly and process lines of car and machining industries. This can lift up an object, the weight of which is from 5 to 200 kg, and moves it to a position. As industrial technologies evolve, it is required to move an object and fit it into a specified position with greater accuracy, rather than performing simple tasks such as lifting objects up and down as conventional ones do. There is also a demand to handle an object with one hand, rather than with two hands,. Through designs of manifold unit for an air balancer function, pilot regulator unit to keep pressure constant, hand unit for an accurate load perception function, and air balancer circuit, this study enables everybody to work it with ease and convenience. Experiments and comparisons were conducted for the performance evaluation of the circuit.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2006.03a
• /
• pp.1159-1164
• /
• 2006

In this paper an artificial neural network model is developed to estimate the unconfined compression strength of Deep Cement Mixing(DCM) treated soil. A database which consists of a number of unconfined compression test result compiled from 9 clay sites is used to train and test of the artificial neural network model. Developed neural network model requires water content of soil, unit weight of soil, passing percent of #200 sieve, weight of cement, w-c ratio as input variables. It is found that the developed artificial neural network model can predict more precise and reliable unconfined compression strength than the conventional empirical models.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.41 no.5
• /
• pp.93-98
• /
• 1999

The results of an experimental investigation on the characteristics of compaction and compressive strength of polypropylene fiber reinforced soil are presented in this paper. This study has been performed to obtain the physical properties of PFRS(polypropylene fiber reinforced soil) such as strain-stress relationships, OMC(optimum moisture contents) and ${\gamma}$dmax (maximum dry unit weight), with four different contents (i.e., 0.1%, 0.3%, 0.5% and 1.0% weights ) of mono-filament and fibrillated polypropylene fibers. From the compaction test results, it is found that OMC increased with the contents ratio of fiber, but ${\gamma}$dmax decreased. It means that the improvement of the workability and the reduction of the weight of embankment structures by the asddtion of the polypropylene fiber. And, from the compression test results, it is found that the additon of the polypropylene fiber remarkably improved the compressive strength of PFRS. And it was observed in the viewpoint of strength that the fibrillated polypropylene fiber reinforced soil is more effective than the mono-filament polypropylene fiber reinforced soil.

• Korean Journal of Adult Nursing
• /
• v.27 no.5
• /
• pp.572-582
• /
• 2015

Purpose: This study was conducted to provide an effective nursing intervention using an individualized educational program composed with knowledge, compliance, and physiologic parameters for long-term hemodialysis patients. Methods: A quasi-experimental study using a non-equivalent control group and pre- and post-test design was conducted with 40 hemodialysis patients at G university hospital in the J city from June to August, 2015. A data was analyzed using frequency, percentage, ${\chi}^2$ test, Shapiro-Wilk test, independent-samples t-test and repeated measures ANOVA using SPSS 21.0 program. Results: knowledge about hemodialysis and patient role behaviors were not significantly different between the two measures. In the biological index, there was significant difference between the groups by points in time and group in blood potassium, albumin, and Kt/v. However, there was no difference in gaining weight between hemodialysis, hemoglobin, and blood phosphorus. Conclusion: The individual training program in this study had an effect on changing some physiological indicators of long-term hemodialysis patients. Future research is warranted for developing various kinds of education program incorporating the findings of the study for the given population.

• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• pp.1624-1633
• /
• 2009

Brake system in railway train operates to reduce the speed of the train or to stop the train via changing the kinematic energy into heat energy for emission and so brake system makes an important rule to transport passenger and cargo for safety operation. Recently operators have a matter of grave concern for the verification of performance in brake system. To verify the exact performance of brake system, most of brake test has been carried out on real operating track condition. Therefore we will determine the braked weight of indirect brake system applied in Iran DMU(Diesel Multiple Unit) in accordance with mc leaflet 544-1, which is to enable Iran DMU to achieve the required braking distances in defined situation.

• Child Health Nursing Research
• /
• v.26 no.4
• /
• pp.434-444
• /
• 2020

Purpose: The aim of this retrospective study was to analyze the characteristics of peripheral arterial ischemia and tissue necrosis in premature babies, as well as the effects of nitroglycerin. Methods: In total, 513 newborns were enrolled who were admitted to the neonatal intensive care unit with a gestational age of 34 weeks or younger. Data were collected on general personal and clinical information, peripheral arterial ischemia, and nitroglycerin patch application in the premature infants. The collected data were analyzed using the χ² test, t-test, Mann-Whitney U test, logistic regression. Results: Thirty-six (7.0%) infants had peripheral arterial ischemia, while 477 (93.0%) infants did not. Lower gestational age (χ²=35.97, p<.001), lower birth weight (χ²=29.40, p<.001), lower blood pressure (χ²=23.10, p<.001), and insertion of an umbilical artery catheter (p<.001) were significantly associated with the occurrence of peripheral arterial ischemia. Among the preterm infants in whom nitroglycerin patches were applied, 30 (83.3%) premature infants without necrosis improved without complications, 4 (11.1%) showed hypotension, and 2 (5.6%) showed skin damage. Conclusion: Based on a review of our experiences with nitroglycerin patches, we recommend closely observing skin color and using nitroglycerin patches on the skin to help improve flow in premature infants with peripheral arterial ischemia.

• Journal of Ocean Engineering and Technology
• /
• v.23 no.3
• /
• pp.20-29
• /
• 2009

This study investigated the shear strength characteristics of waste tire powder-added lightweight soil (WTLS), which were developed to recycle dredged soil, bottom ash, and waste tires. The WTLS used in this experiment consisted of dredged soil, bottom ash, waste tire powder, and cement. Test specimens were prepared with various contents of waste tire powder ranging from 0% to 100% at 25% intervals and bottom ash contents of 0% or 100% by the weight of the dry dredged soil. In this study several series of direct shear tests were carried out, which indicated that the shear properties of WTLS were strongly influenced by the mixing conditions, such as the waste tire powder content and bottom ash content. The unit weight, as well as the shear strength of the WTLS, decreased with an increase in waste tire powder content. The shear strength of WTLS with bottom ash was 1.34 times greater than that of WTLS without bottom ash. An average increase in cohesion of 30 kPa was obtained in WTLS with the inclusion of bottom ash due to the bond strength induced from the pozzolanic reaction of the bottom ash. In this test, the maximum value of the internal friction angle was obtained with a 25% content of waste tire powder.

• The Journal of Engineering Geology
• /
• v.20 no.4
• /
• pp.415-424
• /
• 2010

A prototype of a Concrete-Faced Rock-fill Dam (CFRD) was constructed to evaluate the behavior of the materials in each zone within the dam. The tested materials, selected based on their grain size distribution, were used in constructing the prototype dam with layers of variable thickness, settlement ratio, and water content. We investigated the suitability of various values of hydraulic conductivity, water content, dry unit weight, and settlement ratio for zones within the dam. The test results revealed the relationships between the number of passes and the dry unit weight, between the dry unit weight and the settlement ratio, and between the settlement ratio and the number of passes. This paper focuses on the relationship between hydraulic conductivity and the number of passes. The results of the present analysis could be used to establish reasonable compaction standards for materials used in dam construction.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.32 no.5C
• /
• pp.193-198
• /
• 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.

• Journal of the Korea Concrete Institute
• /
• v.23 no.6
• /
• pp.765-772
• /
• 2011

The present study summarizes a series of compressive tests on concrete cylinder in order to examine the stressstrain relationship of alkali-activated (AA) slag concrete. The compressive strength and unit weight of concrete tested ranged from 8.6 MPa to 42.2 MPa and from $2,186kg/m^3$ to $2,343kg/m^3$, respectively. A mathematical equation representing the complete stress-strain curve was developed based on test results recorded from 34 concrete specimens. The modulus of elasticity, strain at peak stress, slopes of ascending and descending branches of stress-strain curves were generalized as a function of compressive strength and unit weight of concrete. The mean and standard deviation of the coefficient of variance between measured and predicted curves were 6.9% and 2.6%, respectively. This indicates that the stress-strain relationship of AA slag concrete is represented properly with more accuracy in the proposed model than in some other available models for ordinary portland cement (OPC) concrete.