• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1054-1060
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• 2013

Fuel tank of a rotorcraft has a great influence on the survivability of crews. For a long time, US army has tried to develop the proper material for fuel cell of a military rotorcraft. As a result, the design specification of fuel cell, MIL-T-27422A, was issued for the first time on 1961. Through a few revisions, it has been developed to ML-DTL-27422D in 2007. It should be assured that fuel cell satisfies the requirement defined in MIL-DTL-27422D. The qualification test of this specification is classified into Phase I test for material and Phase II for fuel cell itself. This paper studies test conditions and procedures of slosh & vibration, gunfire resistance and crash impact test. They are considered as the most important tests which have a high possibility of failure. The rational consideration of this paper can improve the ability for estimating not only the validity of test procedure and test condition but test result. Based on the rational consideration, it is expected that the ability of the systematic development can be improved.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.328-335
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• 2013

The purpose of this study was to evaluate the height of workbench in dental lab for ergonomic body type which dental technicians are suitable and suggest to effective improvement of workspace. For this purpose, we measured the height, weight, body sizes of total 77 junior majoring in dental laboratory science where they study school located in Gyeonggi and Chungcheong area and we research uncomfortable body type when they had a clinical training. For comparative analysis we had visited 15 dental lab and 2 dental lab of general hospital and we had measured the height of workbench and desk including chair and then We had statistical analysis measured value. Especially we analyzed the important factor causing inconvenience for work environment. As a result, we had examined, we found following results The sand table was the most uncomfortable equipment, when they have clinical training. There is no correlation between sexual characteristics of junior in college and selection of uncomfortable equipment. It is reasonable to assume that sand table which is lower than recommended height brings out inconvenience. It is analyzed that the optimum height of sand table in dental lab for junior in college is lower than the recommended height. The optimum height of sand table in dental lab has deviation according to height of junior in college. The height of worktable in dental lab was lower than recommended height. The recommended range could not apply to posture of dental technician with different height uniformly.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.4
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• pp.35-43
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• 2016

Recently, the pipeline system for waste transportation has been increasingly constructed as new solution for the waste collection and disposal system by constantly increasing domestic waste which issued as social problem. The pipeline system is constructed through long distance, so proper long-term monitoring system is necessary which available to detect the damage location for the effective maintenance. In this paper, the experimental study is carried out to evaluate the applicability of optical strain gauge sensor based on FBG for the long-term monitoring system. Three test parameters such as pressure leaking, blockage and deformation are considered as typical damages for real-scale pipeline test specimen. In order to measure flexural and volumetric strain and temperature, three FBG sensors are installed at each monitoring sections. From the test results, this study suggested effective methods of sensor installation and arrangement. Also the sensor spacing for the design of monitoring system using FBG sensor is derived by the correlation of distances from deformation between sensor responses.

• Journal of Soil and Groundwater Environment
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• v.22 no.6
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• pp.74-84
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• 2017

Soil erosion is often extreme in Korea due to high rainfall intensities and steep slopes, and climate change has also increased the risk of erosion. Despite its significane, erosion-induced soil organic carbon (SOC) emission and water resource loss are not well understood, along with the lack of an integrated surface soil erosion protection policy. Therefore, to design adequate protection policies, land users, scientists, engineers and decision makers need proper information about surface soil and watershed properties related to greenhouse gas emission potential and water conservation capability, respectively. Assuming the total soil erosion of $346Tg\;yr^{-1}$, soil organic matter (SOM) content of 2% (58% of SOM is SOC), and mineralization rate of 20% of the displaced carbon, erosion-induced carbon emission could reach $800Gg\;C\;yr^{-1}$. Also the available water capacity of the soil was estimated to be 15.8 billion tons, which was 14 times higher than the yearly water supply demand in Seoul, Korea. Therefore, in order to prevent of soil erosion, this study proposes a three-stage plan for surface soil erosion prevention: 1) classification of soil erosion risk and scoring of surface soil quality, 2) selection of priority areas for conservation and best management practices (BMP), and 3) application of BMP and post management.

• The Journal of Korean Physical Therapy
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• v.15 no.1
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• pp.61-81
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• 2003

There can be little dissension that the ultimate goal of all physical therapy interventions with the elderly is to restore or maintain the highest level of function possible for the individual. Whenever physical therapists take on this challenge, they assist elders in maintaining their identities as competent adults. Advancing age is associated with profound changes in body composition, including increased fat mass, decreased fat-free mass(particularly muscle), decreased total body water and decreased bone density. Along with these changes in body compositions, and perhaps as a direct result of them, elderly people have lower energy needs, reduced strength and functional capacity and a greatly increased risk for such diseases as noninsulin-dependent diabetes mellitus and osteoporosis. Resistance training is considered a promising intervention for reversing the loss of muscle function and the deterioration of muscle structure that is associated with advanced age. This reversal is thought to result in improvements in functional abilities and health status in the elderly by increasing muscle mass, strength and power and by increasing bone mineral density. In the past couple of decades, many studies have examined the effects of Resistance training on risk factors for age-related diseases or disabilities. We have explored the positive and negative aspects of older adults' participation in resistance training programs. The benefits to older adults are reported to be increased strength, endurance, muscle capacity, and flexibility; more energy; and improved self-image and confidence. The negative aspects include some pain or stiffness and other nonspecific problems. The positive and negative aspects of resistance training are therefore very similar to those in younger populations. Scientific investigations over the past 10 years have demonstrated that resistance training can be safely and successfully implemented in older populations. Even the frail and very sick elderly can benefit and improve their quality of life. Proper design and progression of a resistance training program for older adults is vital to optimal benefits from resistance exercise. The results of data provided by this research on resistance training for health shows that there is enough existing evidence to conclude that resistance training, particularly when incorporated into a comprehensive fitness program, can offer substantial health benefits which can be obtained by persons of all ages. These benefits, including improvements in functional capacity, translate into an improved quality of life.

• Journal of Korea Water Resources Association
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• v.51 no.1
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• pp.61-70
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• 2018

This study examined how to determine the optimal sediment level in dam reservoir for efficient plan and operation of dam. Currently, Korea is applying a horizontally accumulated method for sediment level estimation for the safety design of dam and so the method estimated relatively higher level than others. However, the sediment level of dam reservoir should be accurately estimated because it is an important factor in assessing life cycle of a dam. The sediment level in dam reservoir can be determined by SED-2D model linked with RMA-2, horizontally accumulated method, area increment method, and empirical area reduction method. The estimated sediment level from each method was compared with the observed sediment level measured in 2007 in Imha dam reservoir, Korea and then the optimal method was determined. Also, the future sediment level was predicted by each method for the future trend analysis of sediment level. As the results, the most accurate sediment level was estimated by the empirical area reduction method and the future trend of sediment level variation followed the past trend. Therefore, we have found that the empirical area reduction method is a proper one for more accurate estimation of sediment level and it can be validated by the results from a numerical model of SED-2D linked with RMA-2 model.

• Journal of the Korean Society for Nondestructive Testing
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• v.20 no.6
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• pp.538-544
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• 2000

A phased array ultrasonic nondestructive inspection system is being developed to obtain images of the interior of steel structures by modifying a medical ultrasound imaging system. The medical system consists of 64 individual transceiver channels that can drive 128 array elements. Several modifications of the system were required mainly due to the change of sound speed. It was necessary to fabricate array transducers for steel structure and to obtain A-scan signal that is necessary for the nondestructive testing. Boundary diffraction wave model was used for the prediction of radiation beam field from array transducers, which provided guidelines to design array transducers. And a RF data acquisition board was fabricated for the A-scan signal acquisition along a selected un line within an image. For the proper beam forming in the transmission and reception for steel structure, delay time was controlled. To demonstrate the performance of the developed system and fabricated transducers, images of artificial specimens and A-scan signals for selected scan lines were obtained in a real time fashion.

• Journal of Korean Neurosurgical Society
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• v.30 no.2
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• pp.173-179
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• 2001

Purpose : To assess therapeutic effects of percutaneous polymethylmethacrylate(PMMA) vertebroplasty on the pain caused by osteoporotic thoracic and lumbar vertebral body compression fractures in a large scale of a prospective clinical design, and to determine clinical factors influencing its therapeutic effects. Methods : A prospective clinical study was carried out in 349 vertebral levels of 159 patients between April 1998 and July 1999. The compression fractures were confirmed with bone scan and spine CT, and bone marrow density was measured. Visual analogue scale(VAS) score was used for pre- and post-operative assessments of the pain. All 159 patients were assessed immediately after surgery, and 140 patients of them were followed-up for about 6 months in average. Results : Partial and complete pain relief was sustained immediately after operation in 73%, through follow-up period in 88% of the patients. Pain relief was not proportional to the amount of PMMA or the rate of increase in the height of the compressed vertebral body. It appears that 3 to 6cc of PMMA was proper enough to sustain pain relief. Better clinical improvement was achieved in the patients treated within 6 months after occurrence of vertebral body fracture. The most frequent surgical complication was epidural leakage of PMMA, and the most serious complication was extravertebral leakage into the paravertebral muscles, which appeared to exert the worst influence on the outcome. However, surgery was not required in these patients. Conclusion : Therapeutic effects of PMMA percutaneous vertebroplasty on osteoporotic vertebral body compression fractures were confirmed in a relatively large scale of prospective clinical study. It appears that good outcome can be achieved in patients treated within 6 months after fracture, treated each level with 3 to 6cc of PMMA in amount. without serious complications.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.10
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• pp.669-678
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• 2013

Recently, because the portable devices became popular, it is easily to see that each person carries more than just one portable device and the use of the smartphone stretches as time goes by. After the smartphone has propagated rapidly, the total usage of the smartphone applications has also increased. But still, each application store has a different platform to develop and to apply an application. The application store is divided into two big markets, the Android and the Apple. So the developers have to develop their application by using these two different platforms. Developing into two different platforms almost makes a double development cost. And for the other platforms, the weakness is, which still have a small market breadth like Bada is not about the cost, but about drawing the proper developers for the given platform application development. The web application is rising up as the solution to solve these problems, reducing the cost and time in developing applications for every platform. For web applications don't need to make a vassal relationship with application markets platform. Which makes it possible for an application to operate properly in every portable devices and reduces the time and cost in developing. Therefore, all of the application markets could be united into one big market through a protocol which will connect each web applications market. But, still there is no standard for the web application store and no current web application store is possible to interlock with other web application stores. In this paper, we are trying to suggest a protocol by developing a prototype and prove that this protocol can supplement the current weakness.

• Journal of agriculture & life science
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• v.46 no.5
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• pp.37-45
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• 2012

This study was carried out to examine the optimal treatment conditions of ethanol and glycerine for processing technology development of preserved flowers in carnation (Dianthus caryophyllus) 'Desio' commonly used for flower design. For this purpose, effects of dipping duration of ethanol solution and treatment duration and concentration of glycerine on preserved flower quality were evaluated. Ethanol treatment resulted in perfect dehydration and decoloration of petals and it was proper at 24~48 hours under high brightness and low chroma. Appropriate concentration and time of glycerine treatment was 30% at 36 hours because it resulted in Munsell value of 4.0R in Hue, 6.49 in Value, and 19.8 in Chroma (4.0R 6.49/14) representing the most approximate value to that of fresh petals. Decreasing rate in weight after desiccation tended to reduce by longer time of immersing and higher concentration. Weight after 12 hours of immersing reduced up to 86~90% according to treatment time in non-treatment group of glycerin, meanwhile, it reduced up to 51~69% under higher concentration of 40%. However, weight after 48 hours of immersing reduced up to 90% regardless of desiccation time in non-treatment group of glycerine, to the contrary, decreasing rate reduced by 46~54% through glycerine treatment of 40%. Time for desiccation required 24 hours in glycerin concentration of 10~20% except 6 hours of immersing time, however, higher concentration resulted in increased time up to 48 hours.