• Structural Engineering and Mechanics
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• 제64권4호
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• pp.437-447
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• 2017

Explicit expressions for rapid prediction of inelastic design quantities (considering cracking of concrete) from corresponding elastic quantities, are presented for multi-storey composite frames (with steel columns and steel-concrete composite beams) subjected to service load. These expressions have been developed from weights and biases of the trained neural networks considering concrete stress, relative stiffness of beams and columns including effects of cracking in the floors below and above. Large amount of data sets required for training of neural networks have been generated using an analytical-numerical procedure developed by the authors. The neural networks have been developed for moments and deflections, for first floor, intermediate floors (second floor to ante-penultimate floor), penultimate floor and topmost floor. In the case of moments, expressions have been proposed for exterior end of exterior beam, interior end of exterior beam and both interior ends of interior beams, for each type of floor with a total of twelve expressions. Similarly, in the case of deflections, expressions have been proposed for exterior beam and interior beam of each type of floor with a total of eight expressions. The proposed expressions have been verified by comparison of the results with those obtained from the analytical-numerical procedure. This methodology helps to obtain the inelastic design quantities from the elastic quantities with simple calculations and thus would be very useful in preliminary design.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.510-513
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• 2006

Due to the location of vibration sensitive equipment on the floor, it is necessary for its vibration performance to be maintained within stringent limits, resulting in a design of higher mass and stiffness than would be usual for a floor of this type. Modal testing is conducted on the floor to obtain their dynamic characteristics. A considerable level of vibration transmission is observed by comparing the ratio of simulated transfer and point mobility FRFs of the floor.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.425-426
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• 2012

• 설비공학논문집
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• 제12권5호
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• pp.476-485
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• 2000

This study numerically investigates thermal comfort in a space cooled by the floor-supply air conditioning system, in which three different supply-return locations, one floor supply-ceiling return and two floor supply-floor returns, are treated. A complementary experiment is peformed to validate the present numerical analysis, and the prediction agrees favorably with the measured data. In the numerical procedure, a simplified model mimicking the inlet flow through the diffuser is developed for efficient simulations. The calculated results show that the ceiling return type is far better in thermal comfort than the floor return ones within the extent of this study, which seems to be caused by effective vertical penetration of the supply air against natural convection. It is also revealed that the arrangement of port locations in the floor supply-floor return system has insignificant effect on the cooling performance. For selecting a proper system, other characteristics including the heating performance should be accounted for simultaneously with the present estimation.

• 치과방사선
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• 제28권1호
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• pp.111-126
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• 1998

In this study, radiographic evaluation was made using panoramic radiography and cross-sectional tomography of SCANORA/sup (R)/ in male and female adults in their 20's on the relationship between the maxillary sinus floor and the apex of the maxillary molar, to test the accuracy and effectiveness of the cross-sectional tomography, and to use this information in the assessment of preop. and postop. root canal treatment, apical surgery, extraction and implantology. Forty-one adults with an average age of 24.4 years were studied using panoramic radiography and cross-sectional tomography. In panoramic view and cross-sectional view, the position of the apices of maxillary molars were classified as separated, contacted, or protruded type; the general shape of the maxillary sinus floor was evaluated horizontally and vertically from cross-sectional tomography. The accuracy of each radiography was tested using maxilla from 5 fresh cadavers from the Anatomy Lab at Yonsei University Dental College, and panoramic view and cross-sectional tomography were taken in the same condition as with the patients. The results were as follows: 1. Panoramic view and cross-sectional view were taken in the maxilla specimen, and the actual distance between the maxillary sinus floor and the tooth apices were measured in the specimen; the median values of the distance from the tooth apices to the maxillary sinus floor in the panoramic view, cross-sectional view and in the actual maxilla specimen were 2.83 mm, 4.51mm, and 4.l5mm, respectively. In the cross-sectional view, the measured distance was close to the actual distance but in the panoramic view, the measured distance was far from the actual distance. 2. When the results of the panoramic view and cross-sectional view were compared, 40.5％ of the results agreed with each other in the two radiographic methods and buccal roots of the 2nd molar were the closest to the maxillary sinus floor in the cross-sectional tomography. 3. In cross-sectional view, when the vertical relationship of the maxillary sinus floor and maxillary roots was assessed, in 1st molars, type II (the sinus floor that extends down to the buccolingual furcation area) was predominant, while in 2nd molars, type I (the sinus floor located above the level connecting the buccal and lingual apices) was predominant. In the horizontal relationship, in 1st molars, type II (the lowest floor of the maxillary sinus located in between the buccal and lingual roots) was predominant; in 2nd molars, type I (the lowest floor of the maxillary sinus located on the buccal side of the buccal roots) and type II appeared in similar frequency. In conclusion, the SCANORA/sup (R)/ cross-sectional tomography was more effective than the frequently used panoramic view, in that the relationship of the maxillary molars and maxillary sinus floor can be evaluated more accurately and the buccolingual cross-sectional view can also be observed. And maxillary sinus floor that was close to maxillary 2nd molar had tendency to be located on buccal side than that close to 1st molar. Therefore, cross-sectional tomography is an effective and accurate method to evaluate the position of the teeth in relation to the sinus floor preoperative and can be easily used to diagnose localized periapical lesions. Also, the image quality obtained was quite satisfactory.

• Smart Structures and Systems
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• 제23권1호
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• pp.91-106
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• 2019

Adopting sloped rolling-type isolation devices underneath a raised floor system has been proved as one of the most effective approaches to mitigate seismic responses of the protected equipment installed above. However, pounding against surrounding walls or other obstructions may occur if such a base-isolated raised floor system is subjected to long-period excitation, leading to adverse effects or even more severe damage. In this study, real-time hybrid simulation (RTHS) is adopted to assess the control performance of a smart base-isolated raised floor system as it is an efficient and cost-effective experimental method. It is composed of multiple sloped rolling-type isolation devices, a rigid steel platen, four magnetorheological (MR) dampers, and protected high-tech equipment. One of the MR dampers is physically tested in the laboratory while the remainders are numerically simulated. In order to consider the effect of input excitation characteristics on the isolation performance, the smart base-isolated raised floor system is assumed to be located at the roof of a building and the ground level. Four control algorithms are designed for the MR dampers including passive-on, switching, modified switching, and fuzzy logic control. Six artificial spectrum-compatible input excitations and three slope angles of the isolation devices are considered in the RTHS. Experimental results demonstrate that the incorporation of semi-active control into a base-isolated raised floor system is effective and feasible in practice for high-tech industry.

• Asian-Australasian Journal of Animal Sciences
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• 제30권9호
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• pp.1253-1260
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• 2017

Objective: Purpose was to determine the effects of grazing system and floor type on concentrations of blood metabolites, activity of creatine kinase, body weight and carcass characteristics of castrated Nguni goats. Methods: Forty eight, 7 month old goats were randomly allocated to herding and tethering treatments from 0800 to 1300 hours and accommodated on slatted and earth floors daily. Blood samples were collected by jugular venipuncture every fifteenth day for metabolite analysis. Slaughter was done at a commercial abattoir following 5 months of monitoring. Results: Tethered goats had significantly higher concentrations of urea (5.19 mmol/L) (p<0.001), creatinine ($55.87{\mu}mol/L$) (p<0.05), total protein (64.60 g/L) (p<0.01), and globulin (49.79 g/L) (p<0.001), whereas herded goats had higher glucose (3.38 mmol/L) (p<0.001), albumin (15.33 g/L) (p<0.05), albumin/globulin ratio (0.34) (p<0.01), and body weight (24.87 kg) (p<0.001). Slatted floors caused higher (p<0.01) albumin at 15.37 g/L. The interaction of grazing system and floor type affected creatinine, total protein, globulin at (p<0.01) and albumen/globulin ratio at (p<0.01). The least creatinine concentration and albumin/globulin ratio was in herded and tethered goats that were accommodated on earth floors, respectively. The highest total protein and globulin concentrations were in serum of tethered goats that were accommodated on earth floors. The highest (p<0.05) dressing percentage (45.26%) was in herded goats accommodated on slatted floors. Conclusion: Herding of goats lowered globulin concentration, improved estimated feed intake, blood glucose and albumin concentrations, albumin globulin ratio, increased body weights and weight related carcass characteristics. Floor type had very little effects on metabolites where earth floors only reduced albumin concentration. Tethering and housing goats on earth floors resulted in double stress that increased chronic infections.

• 한국소음진동공학회논문집
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• 제27권1호
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• pp.5-13
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• 2017

Noise complaints among neighbors in apartment building are mainly caused by floor impact noise that is structure born noise due to occupant induced floor vibration. To control this noise problems many researchers have investigated floor systems and finishing materials. Light-weight impact noise affects by finishing materials, but heavy-weight impact noise induced by heel impacts during normal walking or jumping of children is concerned with structural system and floor vibration. To figure out the characteristics of floor impact noise and transmission of floor vibration due to human activities, vibration tests were conducted in apartment buildings. Impact hammer, heel drop and walking activities were loaded at center of upstairs living room, and accelerations of slabs for both upstairs and downstairs and sound pressure levels for downstairs were measured. The acceleration ratio of transmitted floor vibration to downstairs and human induced vibration in upstairs was between 0.5 and 1.0 according to slab size, wall, and load type. And floor impact noise occurred in the range of natural frequency of slab.

• 한국주거학회논문집
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• 제17권3호
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• pp.19-30
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• 2006

The purpose of this study was to compare the characteristics of floor plan of $85m^2$-sized housing units with 2-bay and 3-bay and the residents' satisfaction with them. The subjects for analyzing floor plan were six floor plans of $85m^2$-sized housing units with 2-bay and nine floor plans of housing units with 3-bay in the new town, Hwamyeong-dong, in Busan. The floor plans were analyzed based on seven characteristics of floor plans such as the composition type of entrance core hall, the entrance arrangement, width and depth of the housing unit, size of each room, LDK arrangement, arrangement of family bathroom and private bathroom for husband and wife, and balcony arrangement. The subjects for grasping satisfaction with each housing unit were 400 residents of $85m^2$-sized housing units. A half of them lived in housing units with 2-bay and another half of them with 3-bay in the same area. They answered about the degree of satisfaction with the characteristics of each room and the preferred floor plan type if they move to the same size housing units through a questionnaire. The results were as follows; First, the floor plan with 3-bay had more diverse elements than one with 2-bay. Second, the residents who lived in 3-bay housing unit were younger, higher education, and higher income than the ones in 2-bay. Third, the residents who lived in $85m^2$-sized housing unit were more satisfied with and preferred to 3-bay housing units than 2-bay one.

• 교육시설
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• 제13권3호
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• pp.48-55
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• 2006

This paper considered the situation of the school building facilities in the university classified by the campus characteristics. Data were collected from 224 universities campus of 180 4 year colleges. The results are as follows: 1) The floor area of school building facilities increases continuously in 2001-2003 in the campuses studied. The floor area of school building facilities per 1 student increase $15.85m^2$ in 2001, $17.62m^2$ in 2002, and $17.79m^2$ in 2003. 2) The floor area of school building facilities is distributed widely, also the floor area of school building facilities is below $130,000m^2$ and the floor area per 1 student is below $23m^2$ in 75% of the campuses studied. 3) The floor area of school building facilities per 1 student increases $16.07m^2$ in 2001, $17.41m^2$ in 2002 and $17.62m^2$ in 2003. 4) The floor area of school building facilities per 1 student is large but tends to decrease every year in the university of education. Medical, arts and physical type campus has the large floor area per 1 student and the distribution of area is wide owing to the campus having a hospital. The floor area per 1 student is large and the distribution of area is wide in the sub campus.