• International conference on construction engineering and project management
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• 2015.10a
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• pp.188-191
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• 2015

This study is based on the data of velocity actually measured at varied the heights in the last 3 years. As mentioned in the World Meteorological Monitoring Plan(World Weather Watch: WWW), using the meteorological data by radiosonde can calculate the probability of velocity greater than 10m/s which is the standard beginning point of non-working condition by wind. The height is divided into sections, with 100m for each section starting from the ocean surface up to 700m high. The data measured at each section could be used for estimating and predicting the probability of non-working days for the construction nearby. For example, the data of Osan region is expected to be applicable for the project located in Seoul which has similar geographical conditions. As comparing the velocity varied with height, non-working days calculated basing on the measured data shows a variation of from -0.3 to +64 days. However, this study use Weibull distribution which considered more reliable, the result is expected to be more useful, as the data was all actually measured in the real conditions.

• International Journal of High-Rise Buildings
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• v.13 no.1
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• pp.85-95
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• 2024

A composite member made of concrete-filled steel tubes (CFT columns) has been recognized for its fire resistance due to the thermal mass effect of concrete inside the steel tube, as shown in various studies. In this study, the fire resistance performance of reinforced CFT columns under constant axial load was evaluated using finite element analysis with ABAQUS. For this purpose, the variables including cross-section size, steel tube thickness, and concrete cover thickness were set, and the temperature distribution in the column cross-section exposed to a standard fire was investigated using heat transfer analysis. Ultimately, a P-M interaction curve was obtained by evaluating the overall residual strength of columns, and the fire resistance time was determined by evaluating axial displacement-time responses due to the reduction in load capacity during fire through stress analysis.

• Aerospace Engineering and Technology
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• v.13 no.1
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• pp.10-19
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• 2014

We designed bearingless rotor hub system which replace mechanical hinge/bearing with composite beam component and conducted fatigue analysis for flexbeam and torque tube. Extension/bending/torsional stiffness was calculated from 2D section analysis using VABS and 2D section structure analysis was applied for strain calculation. S-N curve of each composite material was generated using Wohler equation and fatigue analysis was conducted on weakness section which was decided from static structure analysis. CAMRAD II was used for load analysis and load analysis result was applied HELIX/FELIX standard load spectrum to generate bearingless rotor system load spectrum which was used fatigue safe life analysis.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.1
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• pp.149-156
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• 2006

Steel hollow section members have been widely used as a major material in the construction market due largely to their efficiency, their aesthetic appeal and to the technical development. But it is true that the commercial Program for dealing with a joint problem using hollow section members is not firmly established due to its uncertain and variable design parameters. The qualitative analysis program developed by using computer is introduced in this study. The results of that analysis are shown in the two-dimensional space in variable ranges and diagrams, so it would be useful to whom have not many experiences and knowledges. It is represented that the differences between Canadian code and the Korean standard for the connections of hollow section members. And It is verified that the software is applicable to the Preliminary design in steel tubular structures.

• Journal of Fashion Business
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• v.11 no.4
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• pp.69-81
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• 2007

This study, for the purpose of comparing and analyzing 23ea of national unisex apparel brands website consists of product, price, promotion and place divided by marketin gmix. Based of theoretical study and pre-research about the marketing mix, we made the classification standard for the marketing mix and analyzed the unisex apparel brand website according to 4P's individual item and the result was appeared like this. First of all, in the product section, this study provide information about product introduction/guidance, a product figure for item, introduction for new items, propose for coordination and brand introduction/information. Secondly, in the price part, almost apparel brands are provide their product's image, or present their goods photo with price, or displayed through the banner advertisement of discount or special price. Thirdly, For the marketing promotion part, compare to the other component in the most of apparel brand's website, marketing promotion has more section than the other marketing mix. And, especially, various events and customer service space has more weight than the others. Forth, in the place section, it's focused on the information of shopping mall location, contact number, address, and on-line shopping mall. In Conclusion, when the most of apparel brands are doing internet marketing, they're concern to product and promotion, but price and place needs more supplement in the unisex apparel brand's marketing mix.

• Journal of Preventive Medicine and Public Health
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• v.11 no.1
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• pp.14-23
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• 1978

This survey was conducted on a total 672 pulmonary tuberculosis patients who were registered at certain health center in Busan, during the period from July 15th to August 31st, 1977, based on Modified Cornell Medical Index(CMI) consisting of 70 questions. Number of 'Yes' response of an individual patients was collected by each large section of Modified CMI. The each number of 'Yes' response was standardized by mean of Z scoring. Z score was obtained by following formula. Z=50+10(Xi-m)/s M : means of 'Yes' response by each section for all subjects s : standard deviation of the mean Xi : number of 'Yes' response by each section in an individual patients The results of obtained were as follows: 1. The number of investigated cases were 672 (459 males and 213 females). The most prevalent group was 20-24 years old group as 18.4% by age, moderate advanced group as 50.8% by radiological diagnosis, INH+PAS+SM group as 34.7% by antituberculotics and unemployed group as 59.9% by occupation. By bacteriological examination of sputum, the rate of negative group was 60.5% and positive group was 39.5%. 2. Z score of complaints by sex was higher in female as 52.4 than in male as 48.9 in general. By radiological diagnosis, there was decreasing tendency with age in male but increasing tendency with age in female. 3. By age group, Z score of complaints was increasing tendency with age in male but there was non-significant differences in female. 4. By bacteriological examination of sputum, the Z score of complaints was increasing tendency with the more discharged bacteria in both sex generally. 5. By antituberculotics, INH group was revealed the highest Z score of complaints as 50.4 in male and INH+PAS group was the highest as 51.21 in female. 6. By occupation, agricultural and fisherman group was the highest as 53.5 and the next group was professional, technical and related workers, unemployed and sales workers in that order.

• Journal of the Korean Geosynthetics Society
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• v.17 no.1
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• pp.85-93
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• 2018

A existing standard design section of transitional zone between bridge and earthwork section in high speed railway should be designed to gradually change support stiffness from bridge abutment to backfill side that were placed on cemented stabilized gravel, general gravel, soil materials. The larger the backfill slope of the general gravel and soil was more structurally stable, but there is no clear reason about them. In this study, it was compared with settlement and bearing capacity of backfill area in currently design and alternating backfill slope section using large centrifuge tester. As the experimental results, it was showed that the 1:2 slope and 1:1.5 slope have almost similar bearing capacity behavior under the load stage as railway loading level.

• Journal of computational fluids engineering
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• v.20 no.3
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• pp.35-40
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• 2015

Centrifugal pumps consume considerable amounts of energy in various industrial applications. Therefore, improving the efficiency of pumps machine is a crucial challenge in industrial world. This paper presents numerical investigation of flow characteristics in volutes of centrifugal pumps in order to compare the energy consumption. A wide range of volumetric flow rate has been investigated for each case. The standard k-${\varepsilon}$ is adopted as the turbulence model. The impeller rotation is simulated employing the Multi Reference Frames(MRF) method. First, two different conventional design methods, i.e., the constant angular momentum(CAM) and the constant mean velocity (CMV) are studied and compared to a baseline volute model. The CAM volute profile is a logarithmic spiral. The CMV volute profile shape is an Archimedes spiral curve. The modified volute models show lower head value than baseline volute model, but in case of efficiency graph, CAM curve has higher values than others. Finally for this part, CAM curve is selected to be used in the simulation of different cross-section shape. Two different types of cross-section are generated. One is a simple rectangular shape, and the other one is fan shape. In terms of different cross-section shape, simple rectangular geometry generated higher head and efficiency. Overall, simulation results showed that the volute designed using constant angular momentum(CAM) method has higher characteristic performances than one by CMV volute.

• Journal of Environmental Health Sciences
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• v.44 no.5
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• pp.421-432
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• 2018

Objectives: In this study, we started to develop an indoor garden integrated IoT solution based on IAQ (indoor air quality) and interconnection with an environmental database for smart management of indoor gardens. The purpose of this study was to develop and apply an integrated solution for customized air purification from an indoor garden through big data analysis using IoT technology. Methods: An IoT-based IAQ monitoring system was established in three households within a new apartment building. Based on real-time and long-term data collected, $PM_{2.5}$, $CO_2$, temperature, and humidity changes were compared to those of indoor garden applications and the analyzed results were indexed. Results As a result of the installation, all three households had no results exceeding the standard for indoor air pollution on average $PM_{2.5}$ and $CO_2$ indices. In the case of indoor garden installation, the IAQ index increased to the "Good" section after the installation, and readings in the "Bad" section shown before the installation disappeared. The comfort index also did not dip into the "Uncomfortable" section, where it had been preinstallation, and significantly lowered the average score from "Uncomfortable for sensitive groups" to "Good". Overall, the IAQ composite index for the generation of installations decreased the "Good" interval, but "Bad" did not appear. Conclusions In this study on developing an integrated solution for IAQ based on IoT indoor gardens, big data was analyzed to determine IAQ and comfort indexes and an IAQ composite index. Through this process, it became understood that it is necessary to monitor IAQ based on IoT.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.10a
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• pp.334-408
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• 2006

In Hong Kong, large-diameter (${\ge}600mm$) bored piles and large-section excavated rectangular barrettes are commonly used to support tall buildings to resist both vertical and horizontal loads. These piles and barrettes penetrate through and may found in saprolitic soils and decomposed rocks. Generally, the design of these large bored piles and barrettes involves considerable amount of uncertainty and design parameters must usually be verified by field tests. In this paper, over 50 full-scale load tests on large-diameter bored piles and over 15 large-section of rectangular barrettes in Hong Kong are reviewed and interpreted critically, in particular the degree of mobilisation of side shear resistance using a mobilization rating (MR) factor and a displacement index (DI) for floating bored piles and barrettes and rock-socketed piles, respectively. The author was heavily involved with many of these load tests. The diameter of the bored piles tested ranges from 0.6m to 1.8m and the depth varies from 12m to 75m. Sizes of barrettes critically reviewed include $2.2m{\times}0.6m,\;2.2m{\times}0.8m,\;2.8m{\times}0.8m\;and\;2.8m{\times}1.0m$ (on plan) and the depth varies from 36m and 63m. Based on these field tests, a new failure load criterion for large-diameter bored piles and barrettes is developed and proposed. The side shear resistance of the bored piles and barrettes is quantitatively analyzed with respect to local displacements, standard penetration tests, unconfined compressive strength (UCS) for rock sockets and using the effective stress principle. In addition, the effects of construction including post-grouting, construction time, side scraping and excavation tools on side shear resistance are investigated and reported.