• International Journal of Railway
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• v.1 no.3
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• pp.122-127
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• 2008

Rubber components are widely used in many application such as vibration isolators, damping, ride quality. Rubber spring is used in primary suspension system for railway vehicle. Characteristics and useful life prediction of rubber spring was very important in design procedure to assure the safety and reliability. Non-linear properties of rubber material which are described as strain energy function are important parameter to design and evaluate of rubber spring. These are determined by physical tests which are uniaxial tension, equi-biaxial tension and pure shear test. The computer simulation was executed to predict and evaluate the load capacity and stiffness for rubber spring. In order to investigate the useful life, the acceleration test were carried out. Acceleration test results changes as the threshold are used for assessment of the useful life and time to threshold value were plotted against reciprocal of absolute temperature to give the Arrhenius plot. By using the acceleration test, several useful life prediction for rubber spring were proposed.

• Journal of Advanced Navigation Technology
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• v.22 no.4
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• pp.311-318
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• 2018

In this paper, test-bed for the evaluation of wireless communication system on a small launch vehicle is proposed. The proposed test-bed consists of antenna test-coupler, RF attenuators, and RF switch modules. The antenna test-coupler isolates antennas for each band and transmits / receives wireless signals. The RF attenuator and switch are used for path selection of testing signal path. In design and measurement result of the antenna test-coupler, the antenna test-coupler has shielding effect higher than 39.3, 47.1, 56.1 dB at UHF-, S-, X-band. Through testing on small launch vehicle wireless communication system, we were able to successfully transmit and receive data between each test system and launch vehicle with antenna path switching.

• KIPS Transactions on Software and Data Engineering
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• v.11 no.2
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• pp.67-80
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• 2022

Recently, many laundry home appliances have been released with Internet of Things (IoT) functions, but there are few quality evaluation tests for IoT functions. In particular, since IoT test items are not prepared for laundry home appliances applied with IoT functions, it is difficult to find the cause even if defects occur, and test institutions are limited in selecting test items related to IoT and conducting proper performance tests. In this paper, we design a test item framework that separates IoT test items into commonality and variability to identify product defects and causes for laundry home appliances with IoT features among products in the field of home appliances. Through the proposed research, manufacturers and test institutions can test the proper performance of laundry products with IoT functions, which can improve the completeness of the products and ensure reliability.

• Proceedings of the KSR Conference
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• 2003.10b
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• pp.151-156
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• 2003

The purpose of this study is to establish the test procedure of concrete slab track and to estimate the performance of newly developed slab track. The basic direction of conceptual design of KRRI Slab track was determined in the viewpoint of running safety, economic efficiency and maintenance costs. Based on the research results, a detailed conceptual design of KRRI slab track is suggested. For the systematic development of slab track, a comparative study is carried out, comparing merits and demerits of each slab type, and used in the design process of slab track. Slab track tests were performed at lab and the slab track system was improved by the experiment result. Site Test also were performed in test slab track.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.188-193
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• 2007

Airport railroad have required maximum design speed 120km/h and wind speed 50m/s condition as design item of airport railroad vehicles. To design and manufacture the vehicle satisfying these conditions, it must carry out the dynamic behaviors analysis such as hunting stability, ride comfort derailment ratio, unloading ratio and lateral force to meet the criterion described in Urban Railroad Act. Dynamic behaviors of vehicle have carried out using the multi-body dynamics simulation program(VAMPIRE). This paper presents the evaluation methods and criterion used to verify dynamic performance of airport railroad vehicle, and show the analysis results of vehicle dynamic simulation and the test results for vibration and ride comfort measured on running performance tests. As a results, each analysis results and test results meet the criterion described in Urban Railroad Act.

• The Mathematical Education
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• v.47 no.4
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• pp.487-503
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• 2008

In this paper, descriptive assessment method for middle school mathematics was evaluated by developing a framework for designing and grading problems for descriptive assessment and analyzing the effectiveness of the problems. The new descriptive assessment problems were developed by reviewing the current 7th National Mathematics Curriculum of Korea and aligned mathematics textbooks to define a set of problem design principles and evaluation framework for the assessment strategy. The developed problems were first pilot tested and then revised based on the feedback from the test. The final version was field tested by 100 students in 7th grade middle school. After the field test, the problems were graded by two middle school math teachers and one math education researcher to determine the overall correlation between graders and also to analyze effectiveness of the evaluation framework of the test. This result of this study is expected to assist in the further development of descriptive problems and grading framework by providing a reference work for teachers to better understand the process and the limitations of executing the new assessment strategy.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1132-1140
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• 2009

Recently soil improvement methods are using in many ways such as costal and soft ground of inland. Among them, sand compaction pile be widely used because of quiet few advantages. There are two ways for quality evaluation method of sand compaction pile. Especially standard penetration test is used the most general method. However, Current method have problems in that it is not consider the condition of construction site. Therefore this study is propose new quality evaluation method. Relation of N-$\Phi$ is always not fixed but changing by condition of construction site. By through the Laboratory test we can know relationship between relative density and internal friction. Also this study propose revision for effective stress. From these study, we can acquire more accurate and reasonable result than current method.

• Korean Journal of Adult Nursing
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• v.21 no.5
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• pp.468-476
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• 2009

Purpose: This study was to develop the clinical competency evaluation, and to examine the effects of the developed evaluation by comparing it with existing evaluation on clinical competency, communication skill, and self-efficacy of nursing students. Methods: Design was a randomized control group post-test design. The subjects were 102 senior nursing students(Experimental group: 48, Control group: 54) at K university in seoul, Korea. The experimental group took the clinical competency evaluation using standardized patients and the control group took the existing evaluation using a doll. The clinical competency and communication skills were measured by evaluators, and self-efficacy was self reported by the nursing students. Results: The experimental group had higher scores in clinical competency, communication skills, and self-efficacy than those in the control group. Conclusion: Through these results, practice education of nursing education programs need to activate the clinical competency evaluation using standardized patients.

• Fashion & Textile Research Journal
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• v.18 no.4
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• pp.520-530
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• 2016

This research aims to propose an ergonomic design process for hip protector based on previous studies, existing products, multidisciplinary experts opinion, and wearing test. The elderly are more likely to suffer a hip fracture when they fall due to their physical changes in skeletal form, muscle quantity, bone density, and joint movement. A hip protector is an effective product to prevent hip fractures in the elderly but it also has a problem in that it is uncomfortable. Therefore there is a high chance that it won't be able to prevent hip fractures properly. Since the comfort of a hip protector is one of the most critical elements in preventing a hip fracture, we need to keep improving the hip protector for mobility and usability. Based on the previous studies and limitations of current hip protector products, we need to come up with an optimal design for the Korean elderly. First, knowledge has to be built relating to the ergonomic design of the hip protector considering body shape and size analysis using 3D-scan data, and biomechanical analysis on hip fracture. Second, we need to develop a design process including hip protector pattern design, and wearing evaluation with virtual system. Third, we suggest to reevaluate and verify the design procedure from impact evaluation using testing simulator, virtual evaluation of impact, to wearing comfort and usability evaluation. This design process presented in this study would be expected to contribute to the development of ergonomic hip protector which is suitable for the Korean elderly.

• Journal of the Korean Geosynthetics Society
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• v.15 no.2
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• pp.1-12
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• 2016

In this study, laboratory mixture design test and field test were performed to evaluate applicability of eco-friendly binder material (CMD-SOIL) using desulfurized dust in deep cement mixing method (DCM). As a result of laboratory mixture design test, the uniaxial compressive strength of CMD-SOIL was up to 1.136 times bigger than slag cement by changing the water content, mixing rate, and W/B. Also, it had shown the strength up to 1.222 times bigger in shell content and up to 1.363 times in mixing of floating soil. As a result of field test, field strength/laboratory design criterion strength ratio (${\lambda}$) is shown 0.77. And this result was similar to earlier studies. From this result, CMD-SOIL can show the same efficiency compared with existing binder.