• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3A
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• pp.277-286
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• 2010

Derrick or caterpillar crane is generally used for the long-span/cable-stayed bridge construction by pre-cast segment lifting from over-land or water transportation. The heavy weight of them, however, could make defects on unstable under-construction structure and, furthermore a method of conventional segment transportation is also able to occur additional time and cost. In this study, in order to improve conventional construction method, the newly developed derrick crane is mainly considered. It could be not only eccentrically loadable on constructing girder but having rotatable boom for segment transportation from back-side. A series of construction stage using developed derrick crane is defined and also its numerical analysis is conducted. To reflect load characteristics of developed derrick crane on construction stage analysis, on/out of service load is separately calculated by considering vertical/lateral rotation range of boom and it is loaded on 4 fixed positions of crane. The derrick crane on this study could be time and cost saving solution for cable-stayed bridge construction and also make contributions to construction load reduction in its process.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.5
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• pp.27-33
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• 2010

In this study, a monotonic loading test to estimate structural capacity of 12 meter long full scale precast pre-stressed concrete beam specimen was performed with a 2,000 kN dynamic actuator. A couple of embedded steel plate was installed at the ends of the beam and specimens were connected to steel girder frame with high tension bolts. Nominal compressive strength of pre-stressed concrete beam and slab were 50 MPa and 24 MPa respectively. Two HD25 tensile steel reinforcements were welded on vertical plate of embedded steel plate. Pre-stressed concrete beam specimen was loaded by displacement control method with a certain loading pattern which was repeated loading and unloading with 10mm increment displacement. About 88.34%, 86.97% and 66.83% of displacement restoration ratios were evaluated at elastic, inelastic and plastic behavior region of specimen respectively.

• Journal of the Society of Naval Architects of Korea
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• v.38 no.4
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• pp.75-82
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• 2001

Static loadings on ship structure induced either by water pressure before service such as a tank test and ballasting or by cargo pressure during first laden voyage cause relatively much greater stress than dynamic loadings induced by wave. With these static pre-loadings, the initial residual stresses around welded joint, where fatigue strength is concerned(in most cases, where stress concentration occurs) are expected to be shaken-down in a great extent by the elasto-plastic deformation behavior of material. Therefore, it is more resonable to assess the fatigue strength of ship structure with S-N data which have taken into account the effect of shaken-down residual stresses(re-distributed stresses) on the fatigue strength. In this research work, the re-distribution of residual stresses by the tensile pre-loading is measured using an ordinary sectioning method for specimens of padding plate weldment. Fatigue tests are performed also to evaluate the fatigue strength of the both as-welded and pre-loaded specimens.

• Journal of Korean Association for Spatial Structures
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• v.7 no.1 s.23
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• pp.79-85
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• 2007

Steel plate bonding method with epoxy is common applied to repair and strengthen RC structures, but Steel is apt to corrode quickly, hard to manufacture and heavy. To overcome these defects, it is carried out research on strengthening RC structures with FRP(Fibre Reinforced Polyrner/Plastic) FRP is generally used in the shape of Plate or Sheet, but it has weak point such as premature failure, difficult work. To cope with these problem, NSMR(Near Surface Mounted Reinforcement) which uses CFRP in the shape of Rod is proposed and carried out active research on strengthening effect of variables such as quantity, anchorage length and space of CFRP-Rod. Strengthening with CFRP-Rod is carried out under loading to some degree in fact, and so the amount of pre-loading is selected as variable in this research. The amount of pre-loading is chosen in proportion to nominal strength of non-strengthened specimen with CFRP-Rod.

• Journal of Sensor Science and Technology
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• v.28 no.6
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• pp.355-359
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• 2019

Exosomes, known as nanoscale extracellular vesicles in the range of 30-150 nm, are known to contain clinically significant information. However, there is still insufficient information on exosomal membrane proteins for cancer diagnosis. In this work, we investigated the characteristics of the membrane proteins of exosomes shed by cultured breast cancer cell lines using a surface plasmon resonance (SPR) spectroscopy and pre-activated alkanethiols modified sensor chips. The antibodies of breast cancer biomarkers such as MCU-16, EpCAM, CD24, ErbB2, and CA19-9 were immobilized on the pre-activated alkanethiols surfaces without any activation steps. The purified exosomes were loaded onto each antibody surface. The affinity rank of the antibody surfaces was decided by the relative capture efficiency factors for the exosomes. In addition, an antibody with a relative capture efficiency close to 100% was tested with exosome concentration levels of 10⁴/µl, 10⁵/µl, and 10⁶/µl for quantitative analysis.

• The Korean Journal of Physiology
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• v.21 no.2
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• pp.305-311
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• 1987

To evaluate training effect, the step exercise was loaded to three mem for nine weeks. Step score, cardiopulmonary functions and blood constituents were measured before, during and after the test exercise (50 cm-step exercise and treadmill running), and were compared with the pre-tranining values. The results were as follows: 1) By the training, Harvard step score increased remarkably, expecially in the early stage of training. 2) The post-training values of maximal oxygen uptake increased very significantly and it seemed to be due to increases of stroke volume and tissue oxygen extraction. 3) After the training, the degree of increase in expired volume was small during the treadmill exercise. 4) By the training, increasing rate of respiratory quotient lessened during the exercise and it was considered to be caused by the decreases of carbohydrate consumption and anaerobic metabolism. 5) The blood cholesterol concentrations were harldy changed with this degree of training. 6) The blood lactate level decreased during the recovery periods and the values of the recovery 0 and 5 minutes decreased remarkably, in comparison with the pre-trained values. The above results suggest that the 9 week-training of the step exercise brings about the enhancement of circulatory functions and tissue oxygen utilization, and changes of food-stuffs used during the exercise.

• Journal of the Korea Concrete Institute
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• v.11 no.3
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• pp.171-179
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• 1999

The present research investigated the interaction among loading level, corrosion rate and flexural deflection of reinforced concrete beams. 10cm$\times$15cm$\times$110cm reinforced concrete beams were prepared and subjected to different levels of flexural loading, including 0%, 45% and 75% of the ultimate load. The beams with either a pre-load or a sustained load were also exposed to a laboratory environment with ponding and wetting/drying cycling at room temperature. Half cell potential and galvanized current measurements were taken to monitor corrosion process of reinforcing steel. After corrosion initiation, external current was applied to some of the beams to accelerate corrosion propagation. The beam deflections were recorded during the entire tests. The results indicate that loading level has significant effect on corrosion rate. The beams under a sustained load had much higher corrosion rate than the pre-loaded and then unloaded beams. Significant corrosion may result in an increase in beam deflection and affect serviceability of the structure. The present research may provide an insight into structural condition evaluation and service life predictions of reinforced concrete.

• International journal of steel structures
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• v.18 no.5
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• pp.1483-1496
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• 2018

Negligible research has been conducted to date on how to analyse weakened columns, thus safety risks are still involved when structures are weakened prior to demolition. There are various methods available for demolishing steel structures. One of the most effective methods that has been developed involves pre-cutting steel columns at a certain height, so that the least effort can be used to collapse the structure by means of pulling out some of the columns. This paper presents (a) an experimental setup developed to test the capacity of axially loaded weakened columns, which is used to (b) validate a finite element (FE) model. The two pre-cuts that are presented in this paper are (1) the double window cut and (2) the triangular window cut, which are both commonly used in industry. A column weakened with a double window cut or triangular window cut reduces the axial load capacity by up to 50 and 40%, respectively. The FE models developed predict the axial failure load of weakened columns for a double window cut and triangular window cut are generally within an accuracy of less than 8 and 10%, respectively. It is shown at higher slendernesses the influence of column cuts is less than would be intuitively expected because global buckling becomes dominant.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.2
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• pp.94-102
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• 1991

This study was directed to further clarify the effect of resting time or dietary condition for the improvement of exercise capacity and physical fitness, and the changes of some body consitiuents and physiological functions which are related to the exercise metabolism. Sixteen male students(8 athletes and 8 nonathletes)were participated during 3 weeks(Aug. 20-Sep.9, 1989). Each subject performed two treadmill running trials at an absolute intensity (1 mintute in 3.4mph/15% slope and 2 minutes in 5.5mph/20% slope). In the resting time trials, general diet was fed before 1, 2, 4 and 12 hours of the treadmill exercise loaded. in the dietary condition trials, high carbohydrate(HC), high fat(HF) and high protein(HP) diet were fed before 2 hours of the treadmill exercise loaded. Control trial was that of resting time before treadmill exercise loaded after 12 hours of general diet feeding. Measurement were made to study the change of blood glucose, palmitate, lactate, blood pressure and heart rate. The results obtained are summarized as follows: Mean daily metabolizable period. In resting time trial, the blood glucose concentration of athlete and nonathlete from 2 hours group was similar to control group. The blood palmitate concentration of athlete was increased in 1 and 2 hours group but those of nonathlete was not only increased in 1 and2 hours group but was more increased in 12 hours group, compared with both control group. The blood lactate concentration was increased in all experimental group, compared with both control group and those of nonathlete was much higher than athlets. The elevation rate of blood pressure in pre-and after-exercise of athlete was lower than those of nonathlete. In dietary composition trial, the blood glucose concentration of athlete and nonathlete in HC group was higher than other diet groups. The blood lactate concentration of athlete and nonathlete in HC group was lower than other diet groups. There was no remarkable change of the blood palmitate concentration and heart rate in each dietary composition trial, but those of nonathlete was low in HC and high in HP group. In above results, it was suggested that the effective condition of resting time and dietary composition for the improvement of exercise capacity of nonathlete may be 2 hours and HC diet, respectively. But it was showed that the exercise capacity of athlete may not be affected by experimental condition of resting time, except 1 hour after feeding or of dietary composition because of well adaptation in new exercise condition.

• Journal of Environmental Science International
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• v.21 no.1
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• pp.83-88
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• 2012

This study was divided to three experiments for evaluating the effects of pre- or post-load 1-MCP on quality of 'Fuji' apples exposed to ethylene. The first experiment was compared for fruit quality at room temperature at 7, 14, 21, and 28 days between the control and 1-MCP-treated fruits followed storage of 130, 150, and 170 days. 1-MCP-treated fruits maintained higher fruit titratable acidity and firmness than those of control fruits. The second experiment was compared for fruit quality at room temperature at 7, 14, 21, and 28 days between fruits applied with pre-loaded-1-MCP on ethylene treatments (10 ${\mu}L/L$, 20 ${\mu}L/L$, and 40 ${\mu}L/L$) and control fruits. 1-MCP-treated fruits were not affected by ethylene concentrations, and had higher fruit weight and firmness than those of control. The third experiment was compared for fruit quality at room temperature at 7, 14, 21, and 28 days between fruits applied with pre-loading with ethylene (10 ${\mu}L/L$) followed by ventilation (8 h, or 32 h, or 56 h) and 1.0 ${\mu}L/L$ 1-MCP treatment. As observed above experiments, 1-MCP-treated fruits had higher fruit weight and firmness than those of control fruits, regardless of the delayed applications of 1-MCP.