• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.2
• /
• pp.535-541
• /
• 2020

FCAW is used mainly in the welding of carbon steel and alloy steel because it can be welded in all positions and can obtain excellent quality at sites with variable working conditions. Recently, many studies in Korea have estimated the fatigue strength, residual stress, and deformation, and to develop a fillet welding process. On the other hand, there have been few studies of the mechanical properties based on the strength, macro and magnetic particle test results for fillet welding. This study shows the following results through fillet welding, macro testing and strength testing using SM490A (solid-structure rolled steel) for thick plates using SS400 (rolled steel) for the upper plate and FCAW. The hardness test, macro test and magnetic particle test were then conducted. The hardness tests showed that all result values were smaller than the KS B 0893 standard values of 350Hv. The macro-test showed that each type of welded part was in a normal organic state and that there were no internal errors, bubbles, or impurities on the front of the welded part. Therefore, there were no concerns about lamination. The magnetic particle examination showed no problems.

• Journal of Yeungnam Medical Science
• /
• v.9 no.1
• /
• pp.130-136
• /
• 1992

Fractures of the tibial shaft are the most common among the long bone fractures, and have much difficulty in treatment due to their enumerous complications. Thirty patients with fractures of the tibial shaft were treated with Ender nails under the image intensifier at the Department of Orthopedic Surgery, Yeungnam University Hospital from December 1986 to November 1991. The following results were observed. 1. The average age was 37.3 years and the number of male was three times of the female. The most common cause was traffic accident. 2. Twenty cases out of thirty one were closed fractrure and the remaining 11 were open. The comminuted and segmental fractures were 18(57.7%) in number and the most common fracture site was the middle one third(53%). 3. Average interval from injury to operation was 7.6 days and 19 cases showed associated injuries. 4. The mean duration of the bone union was 18.9 weeks and 2 cases showed the delayed union. 5. Twelve complications were noted such as shortening, varus deformity, delayed union, ankle motion limitation, nail irritation, and soft tissue infection.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.13 no.4
• /
• pp.151-162
• /
• 1980

To clarify the dispersion of pollutants introduced in the coastal region, a series of current measurements, the drogue and drift bottle experiments as well as the dye diffusion experiments were carried out in Onsan Bay and in the coastal waters of Ubong-ri near Ulsan. In the southeastern coastal region of Korean peninsula, that is, in the outside of Onsan Bay, the flood tidal current flows south-south-westward, and the ebb current flows north-north-eastward at a maximum speed of 1.0-1.1 knots at spring tide. In an inlet south of Cape Ubong, an anticyclonic eddy of 1 km in diameter is usually formed during both flood and ebb flows. The tidal current predominates in Onsan Bay at around spring tide. The maximum speed around spring tide was observed to be approximately 0.14 knot, while it was slower than 0.1 knot and variable at neap tide when the wind drift current played an important role. The flood tidal current flows westward while the ebb flow flows eastward in the northern region of the bay. The flood tidal current in the southern region of the bay flows west-north-westward, while the ebb current east-north-eastward. Wind drift currents in the coastal region of southern Korea are generally deduced to be southward in winter, the monthly mean speed being approximately 0.1 knot. Dye solution released at the northwestern corner in Onsan Bay was transported by eastward ebb tidal current toward the mouth of the bay dispersing by the wind. The apparent diffusion coefficient at 150 minutes after release in the bay was calculated to be $4.4\times10^4\;cm^2.sec^{-1}$, whereas that in the anticyclonic eddy was more or less smaller.

• Korean Journal of Cognitive Science
• /
• v.20 no.3
• /
• pp.275-289
• /
• 2009

A new computerized testing system, called the Computerized Multiple-choice Testing (CMMT) system, was introduced. In this system, questions of multiple choice (MC) items are presented first without options, so that students must generate answers for themselves. They can click for the options when they are ready, and can respond within a brief, specified time period. The present study was performed to examine whether this system is effective in reducing backward reasoning, I. e., using the options of MC items as cues to find the correct answer. One hundred and seventy-seven 6th grade students (12 year olds) were divided into two groups so that mean scores from a prior test were equal: The experimental group took an intervening computerized test in the new format, and the control group in the MC format. Five days after the computerized intervening test, a short answer paper-and-pencil final test was given. Testing effect was greater in the new system than in the MC system. Analysis of the final test response in relation to the intervening test response showed that i) the students retained the correct answer in the new system more than in the MC testing system, and that ii) students corrected their previous failures in the intervening CMMT format more than those in the MC format. These results suggest that the new system is effective in reducing backward reasoning.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.6
• /
• pp.4019-4023
• /
• 2014

This study examined the effectiveness of ultrasound on enhancing the dewaterability and volume reduction of bio solids from a waste treatment plant. The test specimen was obtained from a storage tank immediately before the dewatering process at a local treatment plant. The test conditions included the energy levels of ultrasonic waves and treatment time. The tests were undertaken using three types of different treatment processors (7 liter, 1 ton, 7 ton container). The capillary suction time (CST) and the viscosity of sludge, which is one of the influencing factors for dewaterbility, were obtained under various test conditions. The results showed that ultrasound increases the CST of the raw specimens, whereas a significant reduction (20 % of the maximum value) of CST occurred in the sample with ultrasound and flocculent. The decrease in viscosity reached 40 % of the maximum value. A centrifugal test was performed to examine the characteristics of the sludge settlement. The settling rate and time required to reach the final values were both enhanced by the ultrasonic energy. An ultrasonic treatment is potentially useful tool for reducing the amount of released sludge. To examine the possible use of field application, the real scale sonic processor was designed and operated. The results were similar (50 % of the maximum value) to those of laboratory experiments.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.33 no.1
• /
• pp.12-20
• /
• 2015

After the great King Munmu constructed Donggung-palace and Wolji-pond in 674, original landscape could not be estimated due to lack of related materials for some 1,250 years until it was surveyed in 1922. Accordingly, the study, to estimate changes of Wolji-pond landscape more accurately, analyzed the study of Hara(1932) and pictures in the Japanese ruling period etc. - these had not been studied so far. The study results are as follows. As a result of comparing survey maps of 1922 and one of 1975, it was found that during 53 years, whole area excluding island showed eroded part by 2~4m, severely, there was mounding area which was lowered by 10m. And it was identified through survey map of 1922 and pictures of the 1950's that inside southern shore protection of the No. 1 construction site were many landscape-stones(景石) which can make imagine a hill; here was water path. Trace of such path etc. remained just before excavation. 2) The construction site No. 3 and 5 in peak shape were higher than construction site No. 1, 2, and 4. Accordingly, there is high possibility that construction stood on high stylobate. So it is wrong that construction site No. 3 and 5 are restored in same height as other construction sites. Comprehensive restoration basic plan made in 2012 was also wrong. As a result of estimating changes of landscape through pictures before excavation of Wolji-pond, the author could identify changes of landscape in mound area and pumice stones which showed much changes in drawing. The study has limit due to lack of space. But if more pictures can be analyzed, it could further help for estimating original landscape of Wolji-pond.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.12
• /
• pp.678-685
• /
• 2016

Deglutition inspection has been the gold standard for inspection of dysphagia using a penetration device of the division of radiology to date. However, inspection using an endoscope has facilitated diagnosis of dysphagia in recent days. In this study, we compared the results of VFSS alone with those of VFSS combined with FEES to determine if the detection rate of penetration, aspiration, and pharyngeal residue increased. This study evaluated at 130 persons who underwent both VFSS and FEES from December 2013 through March 2014, and used VFSS (FELAVISION, SHIMADZU) and FESS (EVIU LUCERA CV-260SL, OLYMPUS) as devices. After preparing barium diluted solution, yogurt that diluted barium and rice that diluted barium in 2.5 ml, 5 ml, 10 ml by modifying Logemann's protocol in part, and having subjects take the solution, this study confirmed pharyngeal residue, penetration, aspiration etc. VFFS and FEES using full HD video revealed aspiration in 36 of the 130 patients in both inspections. Additionally, aspiration was discovered in 36 patients upon VFFS, but in 41 upon FESS. Although FEES was more sensitive at diagnosing dysphagia, the two inspection methods are complementary, so diagnostic value will be greatly improved when the endoscope operating method and accurate fluoroscopic inspection are combined.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.11
• /
• pp.604-609
• /
• 2016

This study evaluated the long-term performance of RSR (Reinforced Subgrade for Railways) technology which increases the railway line capacity without the need for additional land. Its characteristics include the use of a short reinforcement with rigid wall, which make it possible to apply it in confined spaces. The 7m high and 40m long testbed employed to evaluate the long-term performance was designed and constructed near Jupo station on the Chang-hang line. This line, located close to a local bus route, had collapsed at the subgrade following heavy rainfall. The performance of the new type of subgrade was verified with long term measurements over a 2 year period including the surface and ground settlement, horizontal displacement of the wall, tensile strain of the reinforcement, and settlement of the rail top on the side track. Based on the results of the measurements made until now, we concluded that it had sufficient safety and serviceability for use as a railway subgrade. It is expected that RSR technology could be frequently used at sites which lack the necessary construction materials for an embankment and are located close to functional railway lines and boundaries, in order to settle civil complaints.

• Journal of Convergence for Information Technology
• /
• v.8 no.1
• /
• pp.9-14
• /
• 2018

The purpose of this study was to privide basic data for footwear development according to walking mechanics by comparing gait cycle difference between barefoot walking and walking shoes. The walking period was measured in 30 normal adult women with no foot deformity and abnormality. The first subject walked in sneakers and measured the cycle. And then, the subjects walked barefoot and the period was measured to obtain data. The data were taken form corresponding paired T-test. The results were as follows: In barefoot walking, the stance phase left side(p <.001), right side(p <.005), the loading response left side(p <.009), right side(p <.002) ), the pre-swing left side(p <.002), right side (p <.011), the double stance phase(p <.004) were increased and the mid-stance left side (p <.016), right side(p. 001), the swing phase left side(p<.001) was decreased. This suggests that barefoot walking increases the input of various senses of the foot, which makes stable walking possible. It is necessary to improve shoes based on the walking cycle in the future.

• Journal of the Korean Wood Science and Technology
• /
• v.42 no.4
• /
• pp.407-419
• /
• 2014

The analysis of shape before and after heating, Surface moisture content, Moisture weight change and surface heat distribution by fixed type microwave heating in forms of flat veneer and veneer roll of Korean pine, pitch pine, larch and yellow poplar was conducted. The results were as follows: In case of flat veneer, the quality after microwave heating was comparatively good, but it was somewhat warped. These phenomena may be due to transformation by nonuniform drying stress and stronger effect of local irradiation on the veneers when heating veneer owing to the characteristics of fixed type microwave equipment. In case of the features of roll-shaped veneer heated by microwave, the quality after heating was comprehensively excellent. Especially there was no warping unlike flat veneer. Heat distribution and diffusion were also very stable for roll-shaped veneer and such heat distribution had much influence on surface moisture content and moisture weight loss. Accordingly, the veneer roll would show sufficient drying efficiency in fixed type microwave equipment through a scrutinized examination on generating power and irradiation time according to species and thickness of veneer.