• Industry Promotion Research
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• v.6 no.3
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• pp.19-24
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• 2021

There should be no problem in the measurement system for scientific quality management. In this paper, we want to correctly identify the factors that can affect the measurement results during the measurement process and identify what causes them when the measurement results cause problems in terms of location and variation. Variations in the measurement system are largely described in terms of location and dispersion. Location-related attributes are accuracy, stability, and linearity while dispersion-related attributes are reproducibility and repeatability. Analyzing the factors associated with dispersion is an R&R analysis, in which the size of repeatability and reproducibility is represented by a range of differences between multiple measurements and a range of differences between measurements, and 99% of dispersion is determined. Experimental design can also be used for measurement system analysis. Proper analysis is performed only when the factors causing the fluctuation, the worker and the product, are correctly identified as random or fixed factors.

• KIPS Transactions on Software and Data Engineering
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• v.10 no.6
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• pp.211-222
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• 2021

Recently, frozen and refrigerated appliances on the market are being released with additional IoT functions, but there are few tests on IoT functions. In particular, the existing test system does not have IoT test items for IoT-based frozen and refrigerated appliances, making it difficult for companies to find the cause even if defects occur, and test institutions are also restricted from selecting IoT-related test items and conducting correct performance tests. In this paper, we design a test item framework that can identify product defects and identify causes in the performance test process of frozen and refrigerated products with IoT functions among products in the home appliance field, and propose test methods and management measures using them. Through the proposed research, manufacturers and testing institutions can test the correct performance of IoT-based frozen and refrigerated products, thereby enhancing the completeness and securing reliability of the products.

• Physical Therapy Rehabilitation Science
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• v.11 no.4
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• pp.414-420
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• 2022

Objective: In this study, the test-retest reliability and validity were presented to evaluate the usability of isokinetic rehabilitation equipment for the knee joint. Design: Cross-sectional design, reliability & validity study. Methods: Thirty healthy adults participated in the study. A CSMI dynamometer was used as a standardized measuring device to present the validity of the equipment. It was measured based on the dominant leg. The average peak torque value was selected as the measurement variable. After the measurement, a questionnaire was conducted on safety, satisfaction, and performance through the usability evaluation questionnaire. Results: The knee joint isokinetic rehabilitation equipment showed high reliability with Intraclass Correlations Coefficients (ICC) =0.883~0.956. In order to check the validity of the equipment, the 95% confidence interval of the mean difference limit was confirmed by the Bland & Altman plot. As a result, all three angular velocities showed a smaller confidence interval in the flexion than in extension. There were less than 10 plots that were not included in 2 Standard Deviation (SD) between all measurements. As a result of the usability evaluation questionnaire, the average of the safety domain(4.9±0.4), satisfaction domain(4.1±0.8), performance domain(4.3±0.8). Conclusions: If the product is improved by supplementing the items identified in the usability evaluation process, it is judged that it can be used as a useful device in various knee joint rehabilitation fields.

• Journal of Hydrogen and New Energy
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• v.35 no.2
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• pp.195-204
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• 2024

The study involves a finite element analysis to evaluate the structural integrity of the neck mount block for a type 4 hydrogen storage vessel, with the aim of enhancing its strength and rigidity. The existing neck mount block consists of a fixed part and a sliding part, each comprising a body block for load support, a screw part for neck boss fixation, and bolts. To analyze the vulnerabilities of the neck mount block under bolt fastening and load conditions relative to vehicle travel directions, a structural analysis process was developed. Comparative analysis between the enhanced design and the existing model was performed, resulting in improved strength and rigidity. The objective is to provide guidance for the current product development and to offer fundamental data for the design and structural analysis of future development projects.

• Journal of the Korea Society of Computer and Information
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• v.25 no.3
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• pp.243-250
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• 2020

In this paper, we propose an effective software education scheme for universities. The key idea of this software education scheme is to analyze software curriculum of QS world university rankings Top 10, SW-oriented university, and regional main national university. And based on the results, we propose five improvements for the effective SW education method of universities. The first is to enhance the adaptability of the industry by developing courses based on the SW developer's job analysis in the curriculum development process. Second, it is necessary to strengthen the curriculum of the 4th industrial revolution core technologies(cloud computing, big data, virtual/augmented reality, Internet of things, etc.) and integrate them with various fields such as medical, bio, sensor, human, and cognitive science. Third, programming language education should be included in software convergence course after basic syntax education to implement projects in various fields. In addition, the curriculum for developing system programming developers and back-end developers should be strengthened rather than application program developers. Fourth, it offers opportunities to participate in industrial projects by reinforcing courses such as capstone design and comprehensive design, which enables product-based self-directed learning. Fifth, it is necessary to develop university-specific curriculum based on local industry by reinforcing internship or industry-academic program that can acquire skills in local industry field.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.1
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• pp.41-49
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• 2008

Many machineries and equipments are being changing to various and complicated by development of recent technology and arrival of convergence age in distant future. These various and complicate equipments need more precise outcomes and low-power consumption sensors to get close and exact results. In this paper, we proposed fault tolerance and feedback theorem for sensor network and MEMS circuit which has a benefit of energy efficiency through wireless sensor network. The system is provided with independent sensor communication if possible as unused action, using idle condition of system and is proposed the least number of circuits. These technologies compared system efficiency after examining product of each Moving Distance by developed sensor which gives effects to execution of system witch is reduced things like control of management side and requirement for hardware, time, and interaction problems. This system is designed for practical application; however, it can be applied to a normal life and production environment such as "Ubiquitous City", "Factory Automata ion Process", and "Real-time Operating System", etc.

• Polymer(Korea)
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• v.38 no.2
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• pp.144-149
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• 2014

Large residual stresses are remained in the conventional injection molded products because of the high cavity pressure in packing phase during injection molding process. Conventional injection molding (CIM) invokes distribution of cavity pressure and it has a limitation to obtain product with uniform physical property. Multi-cavity conventional injection molding contains quality deviation among the cavities since flow imbalance occurs during filling phase. Injection compression molding (ICM) is adopted to overcome these limitations of CIM. In this study, molding characteristics of CIM and ICM have been investigated using multi-cavity injection mold. Researches were performed by both experiment and computer simulation through observations of birefringence for transparent resins, polycarbonate and polystyrene in CIM and ICM. As a result, low and uniform birefringence and mold shrinkage were showed in the specimens by ICM that could give a uniform cavity pressure. Deviation of physical property among the specimens in multi-cavity mold shown in CIM was significantly reduced in the specimens by ICM. Through this study it was concluded that the ICM in multi-cavity molding was valid for molding products with uniform property in an individual cavity and also reduced property deviation among the cavities.

• Journal of Engineering Education Research
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• v.12 no.4
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• pp.115-125
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• 2009

The purpose of this study was to suggest efficient method for development of learner's self-directed learning ability through literature review on self-directed learning, component of self-directed learning, development of self-directed learning ability, design education steps adopting problem based learning and project based learning. This study was conducted through literature review on self-directed learning and development of self-directed learning, design education. Design education and project based learning process and problem based learning to extract the items that are common to bring out five steps, and differences in levels of learners based on self-learning led to Grow(1991) model to connect the lessons of 9 steps present the design education steps, that is, the learners ready for learning, the definition of problem and recognition of necessity, team building, related data collection, team learning about real problem with the teacher, select optimal solution, student-centered discussion, models and product creation, testing and evaluation, complement.

• Archives of design research
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• v.14
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• pp.1-7
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• 1996

Designers often hesitate to decide the shape, size, and layout of a product. Though ergonomic principles and data are absolutely needed in this process, they don have enough guidelines to refer. For the refrigerator designers, they also are not convinced of their decision: the vertical position of the freezing and refrigerating rooms, the height of shelves, the shape of door-handle, etc. To support the refrigerator design, we applied several ergonomic methods to the evaluation of refrigerator. EMG was measured to evaluate the load of users lumbar muscle. Based upon the experimental EMG data, we developed a model to estimate the relative load corresponding to the height of refrigerator shelves. Two different layouts of a refrigerator, R/F and F/R styles, were compared with the model. A three-dimensional motion analysis method was used to evaluate the users motion of using a refrigerator. Ten door-handles with the different shapes and positions were evaluated by tracking the rotations of the users arm. Video protocol analysis was used to evaluate the user interface of a control panel in a refrigerator. Finally, we suggested several ergonomic design guidelines based on the facts found in this research and the anthropometric data of the Korean adults. The results of this study can be applied to the ergonomic design of refrigerators

• Elastomers and Composites
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• v.47 no.4
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• pp.336-340
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• 2012

Residual stress in the injection molded part is originated from thermal shrinkage and shear stress during injection molding process. There are many measurement methods of residual stress in the plastic part. Residual stress in opaque products can be measured by chemical cracking test. This method enables the solvent and specimen to react and to cause cracks. Cracks developed according to the level of residual stress. Thus the stresses in plastic part can be quantitatively measured by counting the number of cracks or measuring the size of cracks. Relationship between stress and number of cracks in a plastic specimen has been investigated in this study. Bergen jig was used to give a strain in the specimens those were molded using PC/PBT and PC/ABS. Solvent for the chemical cracking test was prepared using tetrahydrofuran and methyl alcol with the ratio of 1 to 3. Stresses in the specimen can be calculated by strains those were imposed by Bergen jig. Cracks were developed for stress higher than certain level. The number of cracks increased by second order function for stress.