• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.658-659
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• 2009

In this study, fluid-induced vibration (FIV) analyses have been conducted for tall building structure. In order to investigate the aeroelastic responses of tall building due to wind load, advanced computational analysis system based n computational fluid dynamics(CFD) and computational structural dynamics (CSD) has been developed. Fluid domains are modeled using the computational grid system with local grid deforming technique. A fully implicit time marching scheme based on the Newmark direct integration method is used for computing the coupled aeroelastic governing equations of tall structure for fluid-structure interaction (FSI) problems. Detailed aeroelastic responses and results are presented to show the physical phenomenon of the tall building.

• International Journal of High-Rise Buildings
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• v.7 no.3
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• pp.197-214
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• 2018

Tall buildings which began from about 40 m tall office towers in the late $19^{th}$ century have evolved into mixed-use megatall towers over 800 m. It is expected that even mile-high towers will soon no longer be a dream. Structural systems have always been one of the most fundamental technologies for the dramatic developments of tall buildings. This paper presents structural systems employed for the world's tallest buildings of different periods since the emergence of supertall buildings in the early 1930s. Further, structural systems used for today's extremely tall buildings over 500 m, such as core-outrigger, braced mega-tube, mixed, and buttressed core systems, are reviewed and their performances are studied. Finally, this paper investigates the potential of superframed conjoined towers as a viable structural and architectural solution for mile-high and even taller towers in the future.

• International Journal of High-Rise Buildings
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• v.5 no.2
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• pp.117-125
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• 2016

In this paper we discuss the terms "exo-spatial design," "solar carving," and "bridging" as strategies for creating more socially connective tall buildings. As a typology, high-rise residential buildings have a unique set of challenges to becoming fully activated urban participants in the cities in which they are located. While there is a general recognition and appreciation that tall buildings provide identity to a city, there is often criticism of how they relate to their surroundings. Critics have posited that tall buildings are insular and foreboding by their very nature. This paper explores several design avenues for architects to consider in order to improve the social aspect of tall buildings. As all cities become taller and denser to accommodate growth, the need to design social space in, on, and around tall buildings must be continually examined if we are to have cohesive urban fabric that supports communities.

• International Journal of High-Rise Buildings
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• v.5 no.2
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• pp.71-86
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• 2016

This paper summarizes the results of a two-year-long research project conducted by the CTBUH on the life cycle assessment (LCA) of tall building structural systems. The research project was made possible thanks to a $300,000 contribution from ArcelorMittal and the support of some of the most important structural engineering firms and players in the tall building industry. The research analyzed all life phases of a tall building's structural system: the extraction and production of its materials, transportation to the site, construction operations, final demolition of the building, and the end-of-life of the materials. The impact of the building structure during the operational phase (i.e., impact on daily energy consumption, maintenance, and suitability to changes) was also investigated, but no significant impacts were identified during this phase.

• International Journal of High-Rise Buildings
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• v.12 no.2
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• pp.153-162
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• 2023

Achieving sustainable spaces is one of the emerging trends of tall buildings regarding their significant impacts on the cities. Reducing energy consumption and material using is investigated as a widely used approach to achieve more efficient tall buildings. Defining more efficient geometries and form modifications have been adopted for this goal. In this paper the effect of plan shape and diagrid angle on structural efficiency of diagrid tall buildings have been studied. A parametric workbench is applied to generate and analyze models. The goal is to find effective form parameters resulting in more efficient forms. Respectively, all models were generated in Rhino/grasshopper architecturally and analyzed by a finite element plug-in structurally. Based on the results, steeper angles almost cause more displacements and needs to be more stiffened. it can be seen almost more sided models need less weight for the structures and it could lead to more efficient forms.

• International Journal of High-Rise Buildings
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• v.2 no.1
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• pp.63-77
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• 2013

In any subject area related to the provision of safety, failure is typically the most effective mechanism for evoking rapid reform and an introspective assessment of the accepted operating methods and standards within a professional body. In the realm of tall buildings the most notable failures in history, those of the WTC towers, widely accepted as fire induced failures, have not to any significant extent affected the way they are designed with respect to fire safety. This is clearly reflected in the surge in numbers of Tall Buildings being constructed since 2001. The combination of the magnitude and time-scale of the WTC investigation coupled with the absence of meaningful guidance resulting from it strongly hints at the outdatedness of current fire engineering practice as a discipline in the context of such advanced infrastructure. This is further reflected in the continual shift from prescriptive to performance based design in many parts of the world demonstrating an ever growing acceptance that these buildings are beyond the realm of applicability of prescriptive guidance. In order for true performance based engineering to occur however, specific performance goals need to be established for these structures. This work seeks to highlight the critical elements of a fire safety strategy for tall buildings and thus attempt to highlight some specific global performance objectives. A survey of tall building fire investigations is conducted in order to assess the effectiveness of current designs in meeting these objectives, and the current state-of-the-art of fire safety design guidance for tall structures is also analysed on these terms. The correct definition of the design fire for open plan compartments is identified as the critical knowledge gap that must be addressed in order to achieve tall building performance objectives and to provide truly innovative, robust fire safety for these unique structures.

• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.2
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• pp.103-108
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• 2010

This experiment was carried out to select adaptability and forage production and quality of Pasture species at paddy field from 2007 to 2009 at Chungnam province. Among growth characters, 'Tall fescue' and 'Tall fescue mixture (Orchardgrass, Tall fescue, Perennial ryegrass, Kentuck bluegrass, White clover)' were somewhat good for waterlogging, production and disease and insect resistance. Fresh yield of 'Tall fescue mixture' and 'Tall fescue' were the highest as 84,294 kg and 78,400 kg per ha among 6 species. The dry yield of 'Tall fescue mixture' and 'Tall fescue' were also the highest as 20,644 kg and 19,759 kg per ha. The result of this study showed that 'Tall fescue mixture' and 'Tall fescue' had good growth characters and forage productivity at paddy field in middle region of South Korea.

• Korean Journal of Head & Neck Oncology
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• v.20 no.2
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• pp.123-127
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• 2004

Objectives: The tall cell variant is an uncommon variant and has been known as more aggressive form of papillary thyroid carcinoma (PTC). Owing to the rarity of these thyroid cancers, their clinical behavior remains incompletely understood. To elucidate the clinicopathologic characteristics of tall cell variant, we retrospectively reviewed our surgical experience of patients with tall cell variant. Methods: Between August 1993 and July 2004, a total of 11 consecutive patients who were pathologically diagnosed with tall cell variant of papillary thyroid carcinoma were enrolled in this study. All patients underwent total (8 cases) or subtotal thyroidectomy (3 cases) with central compartment node dissections. The lateral neck dissection was added in 6 patients. After the operation, neck ultrasound and serum thyroglobulin were checked regularly during the follow-up period. Results: The mean age of the patients was 56.6years (range, 30-74years) at the time of diagnosis. 3 patients were men, and 8 were women. The mean diameter of tumor was 3.7cm(range, 1.5-6.0cm), and 6 patients had lateral neck node metastasis. Extrathyroidal extension was seen in 5 patients (45%). Loco-regional recurrence was found in 2 patients (18%), and distant metastasis in 1 patient (9%). The 5-year disease free survival rate was 68%. Conclusion: The tall cell variant of papillary thyroid carcinoma is an uncommon disease. Clinicopathologic feature and prognosis of this disease show more aggressive behaviors than ordinary papillary thyroid carcinoma. More aggressive treatment and close follow-up should be undertaken in the tall cell variant of papillary thyroid carcinoma.

• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.1
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• pp.1-5
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• 1991

Tall fescue(Festuca amndinacea Schreb.) is a productive pasture grass that is widely adapted to the soil and climate of Korea. It is regarded, however, as relatively low in palatability and nutritive value. On the other hand, Italian ryegrass(lo1ium rnultz$om Lam.) is highly nutritious and palatable, but is essentially weak in cold tolerance. Numerous investigators have succeeded in producing hybrids between Lolium spp. and Festuca spp. but no improved varieties have resulted. Therefore, intergeneric hybridization of Italian ryegrass with tall fescue is employed in 1984 to improve the adaptive and cold resistance quality of Italian ryegrass. In the mean time, F1-hybrid plants obtained by crossing Italian ryegrass x tall fescue were observed in open field. The results are summarized as follows: 1. Leaf-size and silica cell hair were intermediate between the types of parents but the shape of auricle tended to show Italian ryegrass and auricle-cilia to show tall fescue. 2. Roots of $F_1$-hybrid plants were mainly distributed at top soil and did not produced florescence material. 3. Head type of hybrids was intermediate between the types of parents but ray length was somewhat less than the length of tall fescue ray. Typical Italian ryegrass or tall fescue-like phenotypes were not observed. 4. Anthers of $F_1$-hybrid plants were formed but pollen were not formed. Even though pollen were formed, they were all empty. 5. Hybrid plants were more winterhardy and summer persistency than Italian ryegrass. They showed a equivalent growth to Italian ryegrass in spring and to tall fescue in summer. 6. Chromosome of $F_1$-hybrids was allopolyploid(2n=4~=28) and all $F_1$-hybrid plants were sterile.

• International Journal of High-Rise Buildings
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• v.5 no.1
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• pp.21-30
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• 2016

The structural efficiency of tall buildings heavily depends on the lateral stiffness and resistance capacity. Among those structural systems for tall buildings, outrigger system is one of the most common and efficient systems especially for those with relatively regular floor plan. The use of outriggers in building structures can be traced back from early 50 from the concept of deep beams. With the rise of building height, deep beams become concrete walls or now in a form of at least one story high steel truss type of outriggers. Because of the widened choice in material to be adopted in outriggers, the form and even the objective of using outrigger system is also changing. In the past, outrigger systems is only used to provide additional stiffness to reduce drift and deflection. New applications for outrigger systems now move to provide additional damping to reduce wind load and acceleration, and also could be used as structural fuse to protect the building under a severe earthquake condition. Besides analysis and member design, construction issue of outrigger systems is somehow cannot be separated. Axial shortening effect between core and perimeter structure is unavoidable. This paper presents a state-of-the-art review on the outrigger system in tall buildings including development history and applications of outrigger systems in tall buildings. The concept of outrigger system, optimum topology, and design and construction consideration will also be discussed and presented.