• Journal of Environmental Science International
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• v.15 no.8
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• pp.719-725
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• 2006

Since low-floor apartments ate vertically closer to patting lots and roadways, it is hypothesized that residents in low-floor apartments may be exposed to elevated ambient levels of motet vehicle emissions compared to residents in high-floor apartments. The present study examined this hypothesis by measuring two motor vehicle source-related pollutants(CO and PM10) in ambient air of high-rise apartment buildings within the boundary of industrial complexes according to atmospheric stability The ambient air concentrations of CO and PM10 were higher for low-floor apartments than for high-floor apartments, regardless of atmospheric stability, The median concentration ratio of the low-floor air to high-floor alt ranged from 1.3 to 2.0, depending upon atmospheric stabilities, seasons and compounds. Moreover, the CO and PM10 concentrations were significantly higher in the winter and in the summer, regardless of the Hoot height. Atmospheric stability also was suggested to be important for the residents' exposure of high-rise apartment buildings to both CO and PM10. The median ratios of surface inversion air to non-surface inversion air ranged from 1.2 to 1.7 and from 1.0 to 1.6 lot PM10 and CO, respectively, depending upon seasons. Conclusively, these parameters(apartment floor height, season, and atmospheric stability) should be considered when evaluating the exposure of residents, living in high-rise apartment buildings, to CO and PM10. Meanwhile, the median PMl0 outdoor concentrations were close to or higher than the Korean annual standards for PM10, and the maximum PM10 concentrations substantially exceeded the Korean PM10 standard, thus suggesting the need for a management strategy for ambient PM 10. Neither the median nor the maximum outdoor CO concentrations, however, were higher than the Korean CO standard.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.1
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• pp.8-15
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• 2020

In the present paper, as a way of reducing heavyweight impact sounds, in particular, among floor impact sounds which have come to the forefront as a social issue recently, a floor joist slab is proposed that is expected to bring an effect of reducing heavyweight impact sounds through a shift in the natural frequency by installing a floor joist on a flat-type slab to increase the rigidity of the floor slab, differently from the existing method that increases the thickness of floor slab, and the heavyweight impact sound characteristics depending on the floor joist height and interval are interpretively analyzed. As a result of the analysis, though a trend is shown where the sound pressure level decreases as the slab thickness of floor joist increases, and as no difference is shown when thickness is above a certain value, it is thought that there is a threshold for the effect of an increase in floor thickness on blockage of heavyweight impact sounds. Also, as an increase in floor rigidity resulting from an increase in the floor joist height and a decrease in the interval does not lead to a consistent increase in the performance of blocking heavyweight impact sounds, it is thought that a different floor joist height and interval should be applied to each type of house to expect optimum performance of blocking heavyweight impact sounds, and an increase of 100mm in the floor joist height or a decrease of about 100mm in the interval is expected to bring an effect of reducing heavyweight impact sounds by about 1dB to 2dB.

• The KSFM Journal of Fluid Machinery
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• v.16 no.6
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• pp.19-25
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• 2013

The effect of tip gap height on heat/mass transfer characteristics on the floor of cavity squealer tip has been investigated in a turbine cascade for power generation by employing the naphthalene sublimation technique. The squealer rim height is chosen to be an optimal one of $h_{st}/c$ = 5.51% for the tip gap height-to-chord ratios of h/c = 1.0, 2.0, 3.0 and 4.0%. The results show that heat transfer on the cavity floor is strongly dependent upon the behavior of the cavity flow falling down onto the floor. For lower h/c, the floor heat transfer is influenced by the tip leakage flow falling down along the inner face of the suction-side squealer, whereas the floor heat transfer for higher h/c is augmented mainly due to the impingement of leakage flow on the floor near the leading edge. Compared to the plane tip surface heat transfer, the cavity floor heat transfer is less influenced by h/c. For h/c = 1.0%, the average thermal load is as low as a half of the plane tip surface one, and the difference in the thermal load between the two cases tends to decrease with increasing h/c.

• International Journal of High-Rise Buildings
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• v.12 no.3
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• pp.195-201
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• 2023

This paper reviews the history of the birth and development of the skyscraper in Japan, mainly from the perspective of the legal system, and presents the following points: 1) After 1919, building height was limited to 31 m or less, which continued after the war and defined the skyline of Japan's major cities; 2) The 31-meter height limit became a problem during rapid economic growth. With the development of tall building construction technology, the height limit was eliminated, and skyscrapers were born in Japan in the 1960s; 3) Later, the number of skyscrapers increased more rapidly in the post-bubble period after the collapse of the bubble economy in the 2000s than in the boom years of the 1980s, when the floor-area ratio was relaxed for economic uplift and urban renewal. The number of skyscrapers increased rapidly against the backdrop of the deregulation of the floor-area ratio.

• Journal of Korean Society of Rural Planning
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• v.24 no.2
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• pp.59-67
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• 2018

As high-rise buildings came in, the landscape of rural areas and natural landscapes often got damaged. Therefore, this study aims to prevent this, grasp the extent of the influence of the surrounding landscape, to grasp the range of height that can be permitted and present the direction of landscape management of agriculture and natural landscape. This study tried to grasp the range of height by using price sensitivity analysis method for two apartment and apartment complex which entered DangJin city and SeoSan city. First, in the case of a two apartment, the range of the height allowable section was from the 6th floor to the 11th floor in close range view, and it was a section from the 7th floor to the 12th floor in medium range view. In the case of the apartment complex, the range of the height allowable range was from the 10th floor to the 17th floor in close range view, the 9th floor to the 16th floor in medium range view. The stress index was found to be positive in a two apartment in close range view, and in the apartment complex case. therefore it was better to set it to a lower in the Range of Acceptable Height(RAH). Second, it showed no difference in the sensitivity of landscape to gender. Thirdly, the results of the landscape sensitivity analysis of major and non-major showed the difference in the medium range view picture of the apartment complex. Majors are lower than the point of minimum height(PMinH) than non-Majors. In the case of major, the stress index was 1.4. it turned out that it was better to make a decision closer to point of minimum height (PMinH). In the case of non-major, the stress index was -1.3. it was also able to accept decision close to the point of maximum height (PMaxH). Since the results of the above research gave changes only in the variable of the height of the landscape, we can not grasp the point of interaction with other variables, and future research is considered necessary.

• Journal of Periodontal and Implant Science
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• v.44 no.2
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• pp.50-56
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• 2014

Purpose: The aims of this study were to measure the distance of the intraosseous vascular anastomosis in the anterolateral wall of the maxillary sinus from different reference points, and to correlate the location of the intraosseous vascular anastomosis with the tooth position and the residual bone height of the maxilla. Methods: Computed tomography (CT) images were taken from 283 patients undergoing dental implants placement in the posterior maxilla. Three horizontal lines were drawn at the ridge crest, maxillary sinus floor, and the position of the anastomosis. A vertical second line at the center of each tooth was drawn perpendicular to the horizontal lines. The distance from the ridge crest to the maxillary sinus floor and the distance from the maxillary sinus floor to the bony canal were measured from the intersections of the horizontal and vertical lines. The residual alveolar bone height was used to categorize three groups: group 1,<4 mm; group 2, between 4 and 8 mm; and group 3, >8 mm. Results: The residual bone height values of different tooth positions were significantly different (P=0.0002). The distance from the maxillary sinus floor to the intraosseous vascular anastomosis was significantly different between groups 1 and 3 (P=0.0039). At the molar sites, a moderate negative correlation was found between the residual bone height and the distance from the maxillary sinus floor to the intraosseous anastomosis. The distances of the alveolar ridge crest and the maxillary sinus from the intraosseous vascular anastomosis were not significantly different between sexes. Conclusions: Within the limitations of this study, sites with a higher residual bone height in the molar regions were at a relatively high risk of artery damage during window osteotomy preparation; therefore, we recommend taking more precautions when using a lateral approach for sinus elevation.

• Steel and Composite Structures
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• v.44 no.5
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• pp.677-684
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• 2022

This paper reports experimental investigation on shear behavior of steel reinforced concrete (SRC) shallow floor beam, where the steel shape is embedded in concrete and the high strength bolts are used to transfer the shear force along the interface between the steel shape and concrete. Six specimens were conducted aiming to provide information on shear performance and explore the shear bearing capacity of SRC shallow floor beams. The effects of the height of concrete slab, the size and the type of the steel section on shear performance of beams were also analyzed in the test. Based on the strut-and-tie model, the shear strength of the SRC shallow floor beam was proposed. Experimental results showed that composite shallow floor beam exhibited satisfactory composite behavior and all of the specimen failed in shear failure. The shear bearing capacity increased with the increasing of height of concrete slab and the size of steel shape, and the bearing capacities of beam specimens with castellated steel shape was slightly lower than those of specimens with H-shaped steel section. Furthermore, the calculations for evaluating the shear bearing capacity of SRC shallow floor beam were verified to be reasonable.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.7
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• pp.288-292
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• 2016

The purpose of this study was to improve the refuge safety area in the high-rise building type. Each simulation was conducted to evaluate the performance of three types in improving the refuge safety area. Targeting the first 63 floors (no refuge safety area), secondly, to target up to the $30^{th}$ floor (refuge safety area on the $30^{th}$ floor, $47^{th}$ floor) specified in domestic laws, and finally, the $20^{th}$ floor (evacuation safety area on the $20^{th}$ floor, $42^{th}$ floor) were considered as targets. Through this analysis, the following results were obtained : The floor for the refuge safety area through simulations showed that the evacuation time is low. It is necessary to improve the floor for the refuge safety area by using the characteristics of the domestic fire fighting vehicle. The first floor for the refuge safety area from the ground floor differs according to the distance and height of the building floor. However, in the case of a business facility it is 15F, and in the case of apartment housing, it is 20F.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.7 s.94
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• pp.1864-1873
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• 1993

A biomechanical approach was carried out to analyze foot-floor reaction forces acting on five male subjects performing a walking task. The task analyzed was walking over an obstacle with the right bare foot. The foot-floor reaction data were measured from a force plate, and then processed using a software developed. The source program was coded in the C language for easier on-line data acquisition and graphic displays. High repeatability was found in the reaction data acquired from three trials by each subject. For obstacle height from 0 to 25 cm, the maximum in reaction force reached up to 1.048 BW in the vertical, 0.174 BW in the anterior-posterior, and 0.054 BW in the medio-lateral components, respectively. A quantity was defined by the difference between two vertical reaction values, and this quantity was found to be proportional to the obstacle height. It was also shown that the whole body motion could be predicted the measured foot-floor reaction data.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.11 no.1
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• pp.29-35
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• 2017

It was hard for a conventional care-bed to be realized to a low-floor position due to a complex actuation mechanism installed under the mattress support platform. In this paper a mechanism design to set a low-floor position as well as to adjust back- and leg-rest angles was proposed. A dual motor was applied to the back- and leg-rest mechanism of which design parameters were determined by an optimal method. An elevation mechanism was also designed to enlarge a limited stroke range up to two times of its original stroke using a pulley mechanism. An evaluation test was performed by five healthy subjects ($24.4{\pm}0.5yrs.$) when going up from a floor position to a preset best position which was set to the 240mm height for a prototype low-floor bed and to the 600mm height for a conventional bed. As a result, the moving distance was 38% lower than the conventional bed when the subject used the low-floor bed. It showed that the low-floor care-bed reduced physical burdens and was effective to assist activities of daily living of the elderly people.