• Title/Summary/Keyword: rise height

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Energy Modeling of a Supertall Building Using Simulated 600 m Weather File Data

  • Irani, Ali;Leung, Luke;Sedino, Marzia
    • International Journal of High-Rise Buildings
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    • v.8 no.2
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    • pp.101-106
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    • 2019
  • Assessing the energy performance of supertall buildings often does not consider variations in energy consumption due to the change of environmental conditions such as temperature, pressure, and wind speed associated with differing elevations. Some modelers account for these changing conditions by using a conventional temperature lapse rate, but not many studies confirm to the appropriateness of applying it to tall buildings. This paper presents and discusses simulated annual energy consumption results from a 600 m tall skyscraper floor plate located in Dubai, UAE, assessed using ground level weather data, a conventional temperature lapse rate of $6.5^{\circ}C/km$, and more accurate simulated 600 m weather data. A typical office floorplate, with ASHRAE 90.1-2010 standards and systems applied, was evaluated using the EnergyPlus engine through the OpenStudio graphical user interface. The results presented in this paper indicate that by using ground level weather data, energy consumption at the top of the building can be overestimated by upwards of 4%. Furthermore, by only using a lapse rate, heating energy is overestimated by up to 96% due to local weather phenomenon such as temperature inversion, which can only be conveyed using simulated weather data. In addition, sizing and energy consumption of fans, which are dependent both on wind and atmospheric pressure, are not accurately captured using a temperature lapse rate. These results show that that it is important, with the ever increasing construction of supertall buildings, to be able to account for variations in climatic conditions along the height of the building. Adequately modeling these conditions using simulated weather data will help designers and engineers correctly size mechanical systems, potentially decreasing overall building energy consumption, and ensuring that these systems are able to provide the necessary indoor conditions to maintain occupant comfort levels.

Does Strategy of Downward Stepping Stair Due to Load of Additional Weight Affect Lower Limb's Kinetic Mechanism?

  • Ryew, Checheong;Yoo, Taeseok;Hyun, Seunghyun
    • International journal of advanced smart convergence
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    • v.9 no.4
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    • pp.26-33
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    • 2020
  • This study measured the downward stepping movement relative to weight change (no load, and 10%, 20%, 30% of body weight respectively of adult male (n=10) from standardized stair (rise of 0.3 m, tread of 0.29 m, width of 1 m). The 3-dimensional cinematography and ground reaction force were also utilized for analysis of leg stiffness: Peak vertical force, change in stance phase leg length, Torque of whole body, kinematic variables. The strategy heightened the leg stiffness and standardized vertical ground reaction force relative to the added weights (p<.01). Torque showed rather larger rotational force in case of no load, but less in 10% of body weight (p<.05). Similarly angle of hip joint showed most extended in no-load, but most flexed in 10% of body weight (p<.05). Inclined angle of body trunk showed largest range in posterior direction in no-load, but in vertical line nearly relative to added weights (p<.001). Thus the result of the study proved that downward stepping strategy altered from height of 30 cm, regardless of added weight, did not affect velocity and length of lower leg. But added weight contributed to more vertical impulse force and increase of rigidity of whole body than forward rotational torque under condition of altered stepping strategy. In future study, the experimental on effect of weight change and alteration of downward stepping strategy using ankle joint may provide helpful information for development of enhanced program of prevention and rehabilitation on motor performance and injury.

Analysis of the wearing condition and consumer preference for skateboarding pants - Focusing on Chinese skateboarders - (스케이트보딩용 팬츠에 대한 착용실태 및 소비자 선호도 분석 - 중국 스케이트보더를 중심으로 -)

  • Ma, Xiaoqing;Jang, Jeongah
    • The Research Journal of the Costume Culture
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    • v.30 no.1
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    • pp.50-65
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    • 2022
  • The aim of this study was to provide data to enable the development of skateboarding pants. From the Chinese skateboard club SNS, 126 skateboarders in their 20s and 30s were chosen to participate in a survey. Data was gathered using a questionnaire from May 14 to May 28, 2021, and then analyzed using SPSS 23. The results concerning production were as follows: clothing sizes are generally divided into six stages: XS, S, M, L, XL, and 2XL. The silhouette is wide, and most pants have e-bands and normal hems. The pants are made from cotton-blend fabric, which is mostly moisture-absorbing and quick-drying. Baggy pants are preferred by skateboarders, with cotton being the most common fabric. The crotch, knees, and buttocks of pants are the least satisfying for skateboarders. When they skateboard, their ankles sustain the most injuries, followed by their knees and wrists. In the survey of consumers' preferences for skateboarding pants, different styles were rated in the following order: straight pant silhouette, ribbed knit and string waistband design; full-rise waist height, string hemline design; and ankle-high pants length (fit), fabric and design. The hygroscopicity and ventilation of the fabric are crucial considerations when purchasing pants. In terms of color, chromatic and pastel colors are most popular. In addition, some people expect new fibers to be used and expect protective equipment and pants to be integrated.

Numerical Study on The Effect of Bending Angle on Pressure Change in High Pressure Hose (고압 호스에서 굽힘의 각도가 압력 변화에 미치는 영향에 대한 수치해석적 연구)

  • Hong, Ki-Bea;Kim, Min-Seok;Ryou, Hong-Sun
    • Journal of the Korean Society of Industry Convergence
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    • v.25 no.1
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    • pp.61-70
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    • 2022
  • Fire damage time in high-rise buildings and wildland fire increasing every year. The use of high-pressure fire pumps is required to effectively extinguish fires. Reflecting the curvature effect of the fire hose occurring at the actual fire fighting site, this study provides a database of pressure drop, discharge velocity and maximum discharge height through C FD numerical analysis and it can provide using standards for fire extinguishing. Two Reynolds numbers of 200000 and 400000 were numerically analyzed at 0° -180° bending with water of 25℃ as a working fluid in hoses with a diameter of 65mm, a length of 15m, and a radius of curvature of 130mm. Realizable k-ε turbulence model was used and standard wall function was used. The pressure drop increases as the bending angle increases, and the maximum value at 90° and then decreases. The increasing rate is greater than the decrease. The velocity of the secondary flow also decreases after having the maximum value at 90°. The decreasing rate is greater than the increase. The turbulent kinetic energy increases to 120° and decreases with the maximum value. Pressure drop, velocity of the secondary flow, and turbulence kinetic energy are measured larger in the second bending region than in the first bending region.

Structural performance and SWOT analysis of multi-story buildings of lightweight reinforced concrete comprising local waste materials

  • Walid A., Al-Kutti;A.B.M. Saiful, Islam;Zaheer Abbas, Kazmi;Mahmoud, Sodangi;Fahad, Anwar;Muhammad, Nasir;Muhammad Arif Aziz, Ahmed;Khalid Saqer, Alotaibi
    • Earthquakes and Structures
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    • v.23 no.6
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    • pp.493-502
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    • 2022
  • In recent decades, infrastructural development has exploded, particularly in the coastal region of Saudi Arabia. The rising demand of most consumed aggregate in construction can be effectively compensated by the alternative material like scoria which lavishly exists in the western region. Scoria is characterized as lightweight aggregate beneficially used to develop lightweight concrete (LWC) - a potential alternative of normal weight concrete (NWC) ensuring reduction in the structural element's size, increase in building height, comparatively lighter foundation, etc. Hence, the goal of this study is to incorporate scoria-based structural lightweight concrete and evaluate its impact on superstructure and foundation design beside contributing to the economy of construction. Fresh, mechanical, and rheological properties of the novel LWC have been investigated. The structural analyses employ the NWC as well as LWC based structures under seismic and wind loadings. The commercial finite element package - ETABS was employed to find out the change in structural responses and foundations. The cost estimation and SWOT analysis for superstructure and foundation have also been carried out. It was revealed that the developed LWC enabled a more flexible structural design. Notable reduction in the steel and concrete prices of LWC might be possible in the low-rise building. It is postulated that the cost-effective and eco-friendly LWC will promote the usage of scoria as an effective alternative in Saudi Arabia and GCC countries for structurally viable LWC construction.

Gadanki radar observations of F-region irregularities during June solstice of solar minimum: First results and preliminary analysis

  • Kumar, D.V. Phani;Patra, A.K.;Kwak, Y.S.;Pant, T.K.
    • Bulletin of the Korean Space Science Society
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    • 2009.10a
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    • pp.38.1-38.1
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    • 2009
  • In this paper we present the first results of summer-time F region irregularities during low solar condition observed using the Gadanki MST radar. Echoes were observed on all 20 nights of radar observations and were mostly confined to the post-midnight hours. Echo morphology is very different from the equinoxial post-sunset plume-like features reported earlier from Gadanki. Echo SNRs are lower by 25 dB than their equinoxial post-sunset counterpart, and are quite comparable to the equinoxial irregularities in the post-midnight hours, which are essentially the decaying post-sunset irregularities. The Doppler velocities, which lie in the range of $\pm$ 100 m s-1, show upward/northward motion of the irregularities during the initial phase in contrast to the observed predominant downward/southward velocities associated with the decaying equinoxial post-midnight F region irregularities. Spectral widths of the summer echoes, which are well below 50 m s-1 and are very similar to those of the decaying equinoxial irregularities, represent the presence of weak plasma turbulence. Simultaneous observations made using a collocated ionosonde show no ionogram trace during 2200-0530 LT except for a few occasions. Weak frequency type spread F observed during midnight hours occurred without prior occurrence of range spread F. Concurrent ionosonde observations made from magnetic equatorial location Trivandrum also show very similar result and thus no height rise of the F layer during the midnight hours could be monitored. The preliminary analysis suggests that the post-midnight irregularities reported here are mostly freshly generated ones. The observations are discussed in the light of other observational results reported earlier and the current under standing on the post-midnight occurrence F region irregularities in summer.

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Behaviour and design of stainless steel shear connectors in composite beams

  • Yifan Zhou;Brian Uy;Jia Wang;Dongxu Li;Xinpei Liu
    • Steel and Composite Structures
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    • v.46 no.2
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    • pp.175-193
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    • 2023
  • Stainless steel-concrete composite beam has become an attractive structural form for offshore bridges and iconic high-rise buildings, owing to the superior corrosion resistance and excellent ductility of stainless steel material. In a composite beam, stainless steel shear connectors play an important role by establishing the interconnection between stainless steel beam and concrete slab. To enable the best use of high strength stainless steel shear connectors in composite beams, high strength concrete is recommended. To date, the application of stainless steel shear connectors in composite beams is still very limited due to the lack of research and proper design recommendations. In this paper, a total of seven pushout specimens were tested to investigate the load-slip behaviour of stainless steel shear connectors. A thorough discussion has been made on the differences between stainless steel bolted connectors and welded studs, in terms of the failure modes, load-slip behaviour and ultimate shear resistance. In parallel with the experimental programme, a finite element model was developed in ABAQUS to simulate the behaviour of stainless steel shear connectors, with which the effects of shear connector strength, concrete strength and embedded connector height to diameter ratio (h/d) were evaluated. The obtained experimental and numerical results were analysed and compared with existing codes of practice, including AS/NZS 2327, EN 1994-1-1 and ANSI/AISC 360-16. The comparison results indicated that the current codes need to be improved for the design of high strength stainless steel shear connectors. On this basis, modified design approaches were proposed to predict the shear capacity of stainless steel bolted connectors and welded studs in the composite beams.

Doctor Faustus and the Language of Magic (말로우의 『포스터스 박사의 비극』과 마법의 언어)

  • Park, WooSoo
    • Journal of English Language & Literature
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    • v.56 no.2
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    • pp.237-253
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    • 2010
  • In Christopher Marlowe's Cambridge days in the 1580s, the British forward wits were engaged in the curious pursuit of magic and occult philosophy in order to discover the mystery of things. Magic, together with judiciary astronomy, astrology, mathematics, and logic, was one of the most practical disciplines. Marlowe, Shakespeare, and Jonson demonstrate their deep interest in magic and its language of spell and charms in the light of their analogical application to the alchemical theatre. As Shakespeare says that the poet, the lover, and the madman are of the same because they give forms to airy nothing, a magical illusion is, for the three playwrights, similar to the theatrical illusion in that both magic and theatre work in and by a language and both give us sportive pleasures through the deceptio visus. However, while Jonson is rather puritanically antagonistic to the illusive language of alchemy and magic, Marlowe and Shakespeare are attracted to the rapturous nature of the absolute language of magic. Doctor Faustus' indulgence in magic stands for the Marlovian aspiration for the absolute language which allows no discrepancy between thinking and willing, conceiving and actualizing. His uses of spells, charms, anagrams, and magic books are transformed and translated in the play into an alchemical theatre. Faustus is dependant on and bound by his books of magic, as is the actor on the stage. Faustus is the poet condemned from the beginning. Though he is mistakenly thinking that it is he himself that manipulates Mephostophilis the magical agent, it is otherwise. Faustus is a shadow or an actor in the Elizabethan language. He remains a farcical figure during the twenty-four years which are given to him for his sensual dalliance. Marlowe never forgets through his farcical clowning to satirize such Catholic rituals as exorcism and benediction for their illusive theatricalism. The sports of Faustus' playacting and play-directing rise at the last hour to the height of a tragedy. Ironically Marlowe the playwright succeeds as a tragedian at the point where Faustus fails as a magician.

Holocene Sea Level Reflected from Marine Terrace in Geoje Island and its Influences on Coastal Morphogenesis (거제도 동부해안에서 파악되는 홀로세 고해수준면과 지형발달과정)

  • YANG, Jae-Hyuk
    • Journal of The Geomorphological Association of Korea
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    • v.18 no.1
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    • pp.101-112
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    • 2011
  • Coastal terrace was developed at 7.2m height near Shinchon village in Geoje Island. It is located on the east side of southern coast in Korean Peninsula, where sea-level changes caused by ebb and flow of the tide, embayment are relatively low. Due to the breccia layer by mass-movement, dark grayish clayey formation, marine origin's rounded gravel are deposited sequentially in a cross-section of coastal terrace, so it provides a good example which understand Holocene sea level changes to determine the effect on the various sedimentary environments. For the purpose of identifying the morphogenetic process, Grain size, Roundness, XRD, AMS dating analysis was attempted. As a result, after last glacial age, Holocene sea level rise to +5.6m(4,740±100yrs BP). At that time, various geomorphological features are considered to be formed.

Evaluating Relay Beamwidth for Enhanced Coverage and Data Rates in Buoy-Assisted Maritime Communications

  • Kyeongjea Lee;Tae-Woo Kim;Sungyoon Cho;Kiwon Kwon;Dong Ku Kim
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.18 no.4
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    • pp.922-937
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    • 2024
  • Maritime activities are on the rise, there is a growing demand for high-quality communication services that can cover larger areas. However, the transmission of high data rates to maritime users is challenging due to path loss from land base stations, which limits the transmission power. To overcome this challenge, researchers have been exploring the use of buoys in a marine environment as relays for communication technology. This paper proposes a simulation-based approach to investigate the impact of various beamwidths on communication performance when using a buoy as a relay. The objective is to determine the optimal beamwidth that yields the highest data rate for the target location. The approach is based on an offshore wave model where the direction of the buoy changes according to the height of the wave. The study investigates the performance of the relay in the downlink situation using receive beamforming, and the capacity at the user in the three-hop situation is verified using an amplify-and-forward (AF) relay that uses transmit beamforming to the user. The simulation results suggest that the beamwidth of the relay should be adjusted according to the wave conditions to optimize the data rate and relay position that satisfies a data rate superior to the direct path to the target position. Using a buoy as a relay can be a promising solution for enhancing maritime communications, and the simulation-based approach proposed in this paper can provide insights into how to optimize beamwidth for effective communication system design and implementation. In conclusion, the study results suggest that the use of buoys as relays for maritime communication is a feasible solution for expanding coverage and enhancing communication quality. The proposed simulation-based approach provides a useful tool for identifying relay beamwidths for achieving higher data rates in different wave conditions. These findings have significant implications for the design and deployment of communication systems in maritime environments.