• International Journal of High-Rise Buildings
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• v.9 no.4
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• pp.387-396
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• 2020

While tall buildings are an essential building type to accommodate an ever-growing urban population, as buildings become taller and taller, many design challenges arise. As floor spaces are repeated vertically, the occupants' natural horizontal circulation-based social interactions are limited. As buildings become ever taller, safe evacuation to the ground level becomes more challenging in emergencies. With respect to safety as well as serviceability, one of the most fundamental design challenges of exceedingly tall buildings is their structural systems that make the physical existence of tall buildings possible. While many different design solutions can be sought to resolve these issues as well as other design challenges of extremely tall buildings, this paper investigates the potential of conjoined towers to create more livable and sustainable vertical environments. Emphasis is placed on the social and structural capabilities of conjoined towers in providing enhanced social interactions and more efficient ultra-tall structures. The related brief history of conjoined towers is presented. To understand their current status, contemporary design practices of conjoined towers are discussed. Lastly, a new concept of superframed conjoined towers developed for exceedingly tall building complexes is introduced through design studies. Though envisioning future tall buildings is challenging, conjoined towers can be among the strong candidates toward more livable and sustainable vertical urbanism.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.70.1-70.1
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• 2015

The facility for RAON superconducting heavy-ion accelerator at a beam power of up to 400 kW will be produced rare isotopes with two electron cyclotron resonance (ECR) ion sources. Highly charged ions generated by the ECR ion source will be injected to a superconducting LINAC to accelerate them up to 200 MeV/u. During the acceleration of the heavy ions, a good vacuum system is required to avoid beam loss due to interaction with residual gases. Therefore ultra-high vacuum (UHV) is required to (i) limit beam losses, (ii) keep the radiation induced within safe levels, and (iii) prevent contamination of superconducting cavities by residual gas. In this work, a RAON vacuum design for all the accelerator system will be presented along with Monte Carlo simulation of vacuum levels in order to validate the vacuum hardware configuration, which is needed to meet the baseline requirements.

• Tunnel and Underground Space
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• v.2 no.1
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• pp.102-115
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• 1992

Blasting operations associated with rock excavation work may have an environmental impact in nearby structures or human beings. With the increase of construction work in urban areas, vibration problems and complaints have also increased. In order to determine the optimum design parameters for safe blast, it is essential to understand blast mechanism, design variables involved in blast-induced damage, and their effects on the blasting results. This paper deals with the characteristics of ground vibrations, air blast and fly rock caused by blast, including the general method of establishing the vibration predictors, and damage criteria suggested by various investigators. The results of field measurements from open pit mine and tunnel construction work are discussed. Basic concepts of how to design blast parameters to control the generation of ground vibrations, air blast and fly rock are presented.

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.3
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• pp.617-622
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• 2001

The purpose of this study is to design and the analyze the stress of composited shaft which is wound by filament winding method. The composites shaft has high strength and reduction in weight compared to metal shaft. The classical laminate plate theory(CLT) was used fro analysis the stress, and for structure design. In order to replace metal shaft by composites shaft, the diameter of shaft was determined to $\phi$ 40. The ration of diameter was determined to 0.4 for torsional moment with CLT. In this result of analyzing the stress, composites shaft was safe $30^{\circ}~60^{\circ}$C of winding angle, and was fractured on $90^{\circ}$.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.169-174
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• 2001

This study concerns crack effect on concrete anchor system and prediction of tensile capacity, as governed by concrete cone failure, of single anchors located at center of concrete specimen. To Investigate crack effect three different types of crack such as crack width of 0.2mm and 0.5nm, crack depth of loom and 20cm, and crack location of center and biased point were simulated. The static tensile load was subjected to 7/8 in. CIP anchor embedded in concrete of strength 280kg/$cm^{2}$. Tested pullout capacity was compared to prediction value by each current design method (such as ACI 349-97, ACI 349 revision and CEB-FIP which is based on CC Method), In these comparison CC Method and ACI revision showed almost same value in uncracked concrete specimen, however in cracked concrete CC Method showed conservativeness. Therefore the design by ACI 349 revision is recommended for the safe and economic design.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.04a
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• pp.203-206
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• 2005

The objective of study on composite cylinder for alternative fuel vehicle is to develop safe, efficient, and commercially viable, on-board fuel storage system for the fuel cell vehicle or natural gas vehicle that use highly compressed gaseous fuel such as hydrogen or natural gas. This study presents the whole procedure of development and certification of a type 3 composite cylinder of 207bar service pressure and 70 liter water capacity, which includes design/analysis, processing of filament winding, and validation through various testing and evaluation. Design methods of liner configuration and winding patterns are presented. Three dimensional, nonlinear finite element analysis techniques are used to predict burst pressure and failure mode. Design and analysis techniques are verified through burst and cycling tests. The full qualification test methods and results for validation and certification are presented.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.646-657
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• 2010

Offshore wind power is one of the largest-scale solutions for a nuclear- and pollution-free electricity supply in the future. Recently, the research for offshore wind power has started in Korea. However, there has been little effort specifically made for the exploration and evaluation of mechanical characteristics for offshore underwater soil deposits. In offshore wind power system, this is important as consistent and safe maintenance of structural functionality of the system is key for the wind power system to be successfully implemented. In this study, case examples from foreign offshore wind power sites are selected and analyzed. And design methods and factors of offshore wind power system foundation are investigated.

• Nuclear Engineering and Technology
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• v.29 no.2
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• pp.148-157
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• 1997

A new capsule that has a unique structure in which the test environments including neutron flux and fluence, and irradiation temperature can be controlled precisely during irradiation, was conceptually designed. The capsule structure and instrumentation were successfully designed according to the JMTR's standard procedures of capsule design. Based on the target irradiation, the details of the irradiation such as neutron fluence and irradiation temperature ore calculated and the related capsule safety was evaluated. In addition, the effects of design parameters including the changes in inner-capsule configuration, heater capacity, and Helium gas pressure on the specimen temperature were analyzed with a computer program. Through these thermal and strength evaluations, this capsule was proved to be safe during the irradiation in the JMTR.

• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.5
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• pp.525-531
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• 2015

In this paper, a novel impact sensing device for an ESAF(Electronic Safe and Arming Fuze) is presented. An impact sensing device is mounted in front of a weapon, and it detects an impact when it crashes against a target. There are two main design requirements to enhance the firing functional reliability of the ESAF; an operational reliability and a reduced latency, which is a delay time needed for sensing the impact. The design method of the contact-type impact sensing device, which employs an FPCB(Flexible Printed Circuit Board) so it can be used other weapons, is proposed. The tests demonstrated that the design described in this work show a reduced delay time with ensuring the operational reliability.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.642-647
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• 2007

Determination of loading conditions for tube hydroforming(THF) process that implies an amount of the increment in axial feeding and internal pressure for each step is one of the most important constituents at the process design level. On account of the fact that those design factors mentioned above are imposed simultaneously during the process, suitable loading conditions are required to obtain robust products without any failure such as buckling, necking, bursting and so on. In which, especially, bursting is well known as the most frequently occurred failure in general THF process. In this study, therefore, determination of the loading condition based on the adaptive method was carried out to obtain safe loading paths. In addition, forming limit curves are applied to evaluate the derived loading conditions by using the simulation results. Consequently, it is found that described method in this study for THF process design is useful and has a feasibility.