• Journal of the Korean Geosynthetics Society
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• v.6 no.4
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• pp.29-37
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• 2007

Reduction Factor for Installation Damage required for calculation of design strength of geogrid used in MSEW(mechanically stabilized earth wall) design is usually obtained in the field test simulating real construction condition. However, damages occurred in geogrid during backfill work are influenced by many factors such as polymer types, unit weight per area, backfill construction method and gradation of backfill material and field test considering these factors demands lots of time and costs. In this study, factors affecting installation damage are analyzed and empirical method for evaluating reduction factor for installation damage using maximum particle size in backfill material is suggested.

• IE interfaces
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• v.15 no.2
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• pp.114-125
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• 2002

The objective of this paper is to describe a systematic accident scenario analysis method(SASA) adept at creating accident scenarios for the design of safer products. This approach was inspired by the Quality Function Deployment(QFD) method, which is conventionally used in quality management. In this study, the QFD provides a formal and systematic scheme to devise accident scenarios while maintaining objectivity. SASA consists of three key stages to be broken down into a series of consecutive steps:(1) developing an accident analysis tableau,(2) devising the accident scenarios using the accident analysis tableau,(3) performing a feasibility test, a clustering process and a patterning process, and finally(4) performing quantitative evaluation of each accident scenario. The SASA was applied to a case study of child safety seats. The accident analysis tableau devised 2828(maximum) accident scenarios from all possible relationships between the hazard factors and situation characteristics. Among them, 270 scenarios were devised through the feasibility test and the clustering process. The patterning process reduced them to 29 patterns representative of all accident scenarios. Based on an intensive analysis of the accident patterns, design guidelines for a safer child safety seat were recommended. The implications of the study on the child safety seat case were then discussed.

• Fashion & Textile Research Journal
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• v.21 no.6
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• pp.830-836
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• 2019

A diverse range of products are currently being sold; however, it is very difficult to purchase All-in-One patterns that reflect the body types of the elderly stage in the open market. This study is to develop specialized All-in-One patterns by assessing obese body types characteristics of the elderly social class. Five healthy women with typical obese body types in the elderly stage with busts, waists, and hips surpassing 100 cm were chose as test subjects. The three subjects for the wearing experiment are those with more than one year of experience wearing a bodysuit. A self-evaluation was made three times by looking in the mirror. The data from this study was processed to find averages and deviations; in addition, and a t-test was performed using the SPSS 24 statistical software. A total of 13 body parts were measured prior to and while wearing the specialized All-in-One patterns. Significant results were obtained from all 12 items. All-in-One for research appears to have produced a high level of satisfaction for subjects. This study can provide basic data on elevating the levels of satisfaction of the consumers in their elderly stages with special body types that deviate from standard body types at the time of wearing garments as well as for inner-wear companies to graft this market as a high-value-added niche market.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1691-1694
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• 2005

The fatigue characteristic of a material or a structure is derived from fatigue tests of standard specimens. However test results of standard specimens are very different from those of real structures or components. Therefore, to calculate more accurate fatigue life, the geometrical effect and surface condition must be considered by comparing test results of standard specimens with those of real structures or components. Thus the object of this paper is to evaluate the fatigue characteristic of a real waterwork pipe by conducting fatigue tests with standard specimens and non-standard(plate-shaped) specimens of base metal and weld metal. Also, to evaluate fatigue characteristic based on life distribution, statistical fatigue characteristic was analyzed by the normal distribution and related data of P-S-N curve.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.3 s.180
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• pp.195-202
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• 2006

The degenerative lumbar spinal stenosis (DLSS) is a disease inducing low back pain, leg pain, convulsion. numbness, and neurogenic claudication from compression of nerve root. Intervertebra fixation was reported to increase the degeneration of neighbor lesion after treatment. Recently, a new surgical technique of inserting a fixator between interspinous processes has been introduced. The purpose of this study is to design the interspinous process fixator with flexibility to complement the trouble of using fixator in DLSS. This study evaluated the existing fixator through the mechanical test and modified it using the finite element analysis (FEA). The evaluation was based on the displacement, stiffness and von-Mises stress obtained from the mechanical test and calculated from the FEA in the biomechanical loading condition. Effects of variation in length and thickness were investigated to design an optimal fixator. Three prototypes were manufactured using FEA results. Mechanical tests under the biomechanical loading condition were performed to select the best one from these three. The selected fixator increased flexiblity by 32.9%.

• Korean Institute of Interior Design Journal
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• v.23 no.5
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• pp.157-164
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• 2014

The subject specialization room will be able to support university library users who are inclined to use the general reading room. This study is the research of the area planning for university library's subject specialization room. For the evaluation, 431 users from 15 university libraries in 14 universities located across Seoul were surveyed. Statistical analysis was performed using SPSS. Frequency, percentage, mean, t-test, f-test were used. Results of the study are as follow. Subject specialization rooms in university libraries can be classified via the analysis of spatial characteristics. According to the area ratio of data space and reading space in a subject specialization room, the subject room can be separated into data-loaning and data-reading types. Old libraries are more likely to be data-loaning types, where reading room is small and there are a lot of bookshelves. The annual increase in library collections causes space for bookshelves to decrease. As a result, space for reading has been gradually transformed into space for stacking data. It is necessary to introduce ways to maintain enough space for both reading and stacking data. One way includes movable compact shelving, which can partially replace existing fixed shelves.

• The Journal of Advanced Prosthodontics
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• v.10 no.3
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• pp.245-251
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• 2018

PURPOSE. To evaluate the accuracy of a model made using the computer-aided design/computer-aided manufacture (CAD/CAM) milling method and 3D printing method and to confirm its applicability as a work model for dental prosthesis production. MATERIALS AND METHODS. First, a natural tooth model (ANA-4, Frasaco, Germany) was scanned using an oral scanner. The obtained scan data were then used as a CAD reference model (CRM), to produce a total of 10 models each, either using the milling method or the 3D printing method. The 20 models were then scanned using a desktop scanner and the CAD test model was formed. The accuracy of the two groups was compared using dedicated software to calculate the root mean square (RMS) value after superimposing CRM and CAD test model (CTM). RESULTS. The RMS value ($152{\pm}52{\mu}m$) of the model manufactured by the milling method was significantly higher than the RMS value ($52{\pm}9{\mu}m$) of the model produced by the 3D printing method. CONCLUSION. The accuracy of the 3D printing method is superior to that of the milling method, but at present, both methods are limited in their application as a work model for prosthesis manufacture.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.677-686
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• 2005

The allowable bearing capacity of a pile, the most important factor in stability estimation, is determined by applying safety factor to the ultimate load or yield load. There are several but contradictory methods available in current design codes to estimate the allowable bearing capacity and the safety factor. This paper analyzes load-settlement curves obtained from 19 static load tests measured from 11 sites. At all tests, the load is applied until apparent failure is observed. The validity of the ultimate and yield load estimation method and load caculated from the settlement criterion is investigated through comparison with the measured data. In addition, a new procedure to estimate allowable load and safety factor is proposed. Additional data from field static load tests, such as those incorporated in this study, are needed to more reliably apply the proposed method in design practice.

• Journal of Korean Society for Quality Management
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• v.30 no.1
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• pp.1-21
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• 2002

The purpose of this study was to empirically examine the customer oriented quality creation by considering quality elements required by customers in the product design process. The study tried to extract attractive quality elements by using Kano's model. After identifying the elements HOQ(the house of quality) of QFD(quality function deployment) was used to identify the trend of quality elements evaluation. Test for equal means (t-test) was applied to verify the attractive quality elements of adult shoes. It made us find the customer oriented quality elements from the customer needs and latent dissatisfaction. We collected the opinions of experts on shoes and complete the cause and effect diagram and affinity diagram (KJ method). The data of the questionnaire was put to the QFD and the contents of quality elements was identified by brain storming method. We calculated indexes which were the multiplication of weight and marks of quality elements in the cross table of the HOQ by QFD. Then we tested for the equality of means between the indexes and the sum of attractive quality elements. The results for equal means were statistically significant. To create the customer quality the product design should be differentiated between the age groups over attractive quality elements.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.09a
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• pp.194-199
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• 2001

Lap splice in plastic hinge region is inevitable because of due to constructional joint between footing and column. R/C Circular columns with lap-splice in plastic hinge region are widely used in Korean highway bridges. In addition, these columns which constructed before the seismic design code have a number of structural deficiencies. It is, however, believed that there are not many experimental research works for nonlinear behavior of these columns subjected to earthquake motions. The object of this research is to evaluate the seismic performance of existing circular reinforced concrete bridge piers by the Quasi-static test. Existing reinforced concrete bridge piers were moderate seismically designed in accordance with the conventional provisions of Korea Highway Design Specification. This study has been performed to verify the effect of lap spliced longitudinal steel, confinement steel type and confinement steel ratio far the seismic behavior of reinforced concrete bridge piers. Quasi-static test has been done to investigate the physical seismic performance of RC bridge piers, such as displacement ductility, energy absorption, strength degradation etc.