• Aerospace Engineering and Technology
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• v.6 no.2
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• pp.171-179
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• 2007

The Test Equipment for the upper stage of KSLV-I has following functions via umbilical cable interface; external power supply, command output such as discrete and analog, data acquisition, CS-I interface simulation for first stage of KSLV-I and RS-422 serial communication for PDU. The main purpose of UTE is the experiment or function verification of system-level upper stage. To realize this system, we used PXI control system. The UTE is consisted of the PXI control system, power supply, terminal block, internal harness, connector panel and so on. The software functions of UTE are classified by four blocks. These are Discrete/Analog I/O control, PDU RS-422 serial communication control, power supply GPIB control and UTE remote control. In this paper, we will describe the design on the hardware and software of UTE.

• Aerospace Engineering and Technology
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• v.12 no.2
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• pp.173-179
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• 2013

This paper describes a testbed that was designed and implemented for the development of KSLV-II onboard equipment simulator. It used the CPCI-based industrial hardware system for scalability and the QNX real-time operating system for reliability and real-time simulation. In addition, a real-time application under QNX for function simulations of the KSLV-I PDU was developed and it was verified through interface experiments with KSLV-I upper-stage test equipment. The implemented simulator testbed will be used to verify the development feasibility in the design and development phase of a real KSLV-II onboard equipment simulator.

• Corrosion Science and Technology
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• v.12 no.4
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• pp.191-197
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• 2013

This study is the second stage of developing the corrosion control technical manual about unpainted weathering steel bridge with closed box girder structures. This paper contains selection of corrosive sealant to apply into crevice of upper flange, injecting test of sealant at mock-up equipment with various condition, evaluation of experiment result. Through the experiment of injection of sealants into crevice of mock-up equipment, it is proved that the tar sealant injecting corrosion control method is useful to protect corrosion at box girder upper flange corroded by remaning rain water with calcium chloride.

• Journal of the Korean Society of Radiology
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• v.11 no.5
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• pp.379-385
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• 2017

This study identifies the optimal tube voltages depending on the changes in the patient's body type for limb tests using a digital radiography (DR) system. For the upper-limp test, the dose area product (DAP) was fixed at $5.06dGy{\ast} cm^2$, and for the lower-limb test, the DAP was fixed at $5.04dGy{\ast} cm^2$. Afterwards, the tube voltage was changed to four different stages and the images were taken three times at each stage. The thickness of the limbs was increased by 10 mm to 30 mm to change in the patient's body type. For a quantitative evaluation, Image J was used to calculate the contrast to noise ratio (CNR) and signal to noise ratio (SNR) among the four groups, according to the tube voltage. For statistical testing, the statistically significant differences were analyzed through the Kruskal-Wallis test at a 95% confidence level. For the qualitative analysis of the images, the pre-determined items were evaluated based on a 5-point Likert scale. In both upper-limb and lower-limb tests, the more the tube voltage increased, the more the CNR and SNR of the images decreased. The test on the changes depending on the patient's body shape showed that the more the thickness increased, the more the CNR and SNR decreased. In the qualitative evaluation on the upper limbs, the more the tube voltage increased, the more score increased to 4.6 at the maximum of 55kV and 3.6 at 40kV, respectively. The mean score for the lower limbs was 4.4, regardless of the tube voltage. The more either the upper or lower limbs got thicker, the more the score generally decreased. The score of the upper limps sharply dropped at 40kV, whereas that of the lower limps sharply dropped at 50kV. For patients with a standard thickness, the optimized images can be obtained when taken at 45kV for the upper limbs, and at 50kV for the lower limbs. However, when the thickness of the patient's limbs increases, it is best to set the tube voltage at 50 kV for the upper limbs and at 55 kV for the lower limbs.

• Journal of the Korea Institute of Building Construction
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• v.9 no.4
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• pp.55-61
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• 2009

Recently, the number of high-rise buildings being built in Korea by major construction companies for residential and commercial use has been increasing. When constructing a high-rise building, it is necessary to apply massive amounts of concrete to form a mat foundation that can withstand the huge load of the upper structure. However, it is of increasing concern that due to limitations in terms of the amount of placing equipment, available job-sites and systems for mass concrete placement in the construction field, it is not always possible to place a great quantity of concrete simultaneously in a large-scale mat foundation, and for this reason consistency between placement lift cannot be secured. In addition, a mat foundation Is likely to crack due to the stress caused by differences inhydration heat generation time. To derive a solution for these problems, this study provides test results of a hydration heat crack reduction method by applying placement lift change and setting time control with a super retarding agent for mass concrete in a large-scale mat foundation. Mock-up specimens with different mixtures and placement liftswere prepared at the job-site of a newly-constructed high-rise building. The test results show that slump flow of concrete before and after adding the super retarding agent somewhat Increases as the target retarding time gets longer, while the air content shows no great difference. The setting time was observed to be retarded as the target retarding time gets longer. As the target retarding time gets longer, compressive strength appears to be decreased at an early stage, but as time goes by, compressive strength gets higher, and the compressive strength at 28 days becomes equal or higher to that of plain concrete without a super retarding agent. For the effect of placement lift change and super retarding agent on the reduction of hydration heat, the application of 2 and 4 placement lifts and a super retarding agent makes it possible to secure consistency and reduce temperature difference between placement lifts, while also extending the time to reach peak temperature. This implies that the possibility of thermal crack induced by hydration heat is reduced. The best results are shown in the case of applying 4 placement lifts.

• Journal of Korean Home Economics Education Association
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• v.18 no.3 s.41
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• pp.97-117
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• 2006

The purpose of this study was to investigate the teachers' recognition on the optimization of the educational contents of Clothing & Textiles in subjects of :he Practical Arts or the Technology & Home Economics in the course of elementary, middle and high schools. The statistical data for this research were collected from 203 questionnaires of teachers who work on elementary, middle and high schools. Mean. standard deviation, percentage were calculated using SPSS/WIN 12.0 program. Also. these materials were verified by t-test, One-way ANOVA and post verification Duncan. The results were as follows; First, The equipment ratio of practice laboratory were about 24% and very poor in elementary schools but those of middle and high school were 97% and 78% each and higher than elementary schools. Second, More than 50% of teachers recognized the amount of learning 'proper'. The elementary school teachers recognized the mount of learning in 'operating sewing machines' too heavy especially, the same as middle school teachers in 'making shorts': the same as high school teachers in 'making tablecloth and curtain' and 'making pillow cover or bag'. Third, All of the elementary, middle and high school teachers recognized the levels of total contents of clothing and textiles 'common'. The 80% of elementary school teachers recognized 'operating sewing machines' and 'making cushions' difficult especially. The same as middle school teachers in 'hand knitting handbag by crochet hoop needle', 'the various kinds of cloth' and 'making short pants'. The same as high school teachers in 'making tablecloth or curtain'. Fourth, Elementary school teachers recognized 'practicing basic hand needlework' and 'making pouch using hand needlework' important in the degree of educational contents importance. Middle school teachers recognized 'making short pants unimportant. High school teachers considered the contents focusing on practice such as 'making tablecloth and curtain' and 'making pillow cover or bags' unimportant. My suggestions were as follows; Both laboratories and facilities for practice should be established for making clothing and textiles lessons effective in Practical Arts in elementary schools. The 'operating sewing machines' which were considered difficult should be dealt in upper grade, re-conditioning to easier or omitted. The practical contents should be changed to student-activity-oriented and should be recomposed in order to familiar with students' living. It was needed to various and sufficient supports for increasing the teachers' practical abilities.