• Earthquakes and Structures
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• 제24권2호
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• pp.111-126
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• 2023

Highly reliable and versatile methods artificial intelligence (AI) have found multiple application in the different fields of science, engineering and health care system. In the present study, we aim to utilize AI method to investigated vibrations in the human leg bone. In this regard, the bone geometry is simplified as a thick cylindrical shell structure. The deep neural network (DNN) is selected for prediction of natural frequency and critical buckling load of the bone cylindrical model. Training of the network is conducted with results of the numerical solution of the governing equations of the bone structure. A suitable optimization algorithm is selected for minimizing the loss function of the DNN. Generalized differential quadrature method (GDQM), and Hamilton's principle are used for solving and obtaining the governing equations of the system. As well as this, in the results section, with the aid of AI some predictions for improving the behaviors of the various sport systems will be given in detail.

• Steel and Composite Structures
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• 제18권5호
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• pp.1197-1214
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• 2015

There is a great difference in mechanical behavior between design model one-time loading and step-by-step construction process. This paper presents practical computational methods for simulating the structural behavior of long-span rigid steel structures during construction processes. It introduces the positioning principle of node rectification for installation which is especially suitable for rigid long-span steel structures. Novel improved nonlinear analytical methods, known as element birth and death of node rectification, are introduced based on several calculating methods, as well as a forward iteration of node rectification method. These methods proposed in this paper can solve the problem of element's 'floating' and can be easily incorporated in commercial finite element software. These proposed methods were eventually implemented in the computer simulation and analysis of the main stadium for the Universiade Sports Center during the construction process. The optimum construction scheme of the structure is determined by the improved algorithm and the computational results matched well with the measured values in the project, thus indicating that the novel nonlinear time-varying analysis approach is effective construction simulation of complex rigid long-span steel structures and provides useful reference for future design and construction.

• 한국공간구조학회논문집
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• 제21권1호
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• pp.95-104
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• 2021

As people's living standards and cultural standards have developed, interest in culture and art has increased, and the demand for large space structures where people can enjoy art, music, and sports has increased. As it accommodates a large number of personnel, it is most important to ensure safety of large spatial structures, and can be used as a space where people can evacuate in case of a disaster. Large spatial structures should be prepared for earthquake loads rather than wind loads. In addition to damage to the structure due to earthquakes, there are cases in which it was not utilized as a space for evacuation due to the fall of objects installed on top of the structure. Therefore, in this study, the dome-shaped large spatial structure is generalized and the displacement response according to the number of installations, position and mass is analyzed using a tuned mass damper(TMD) that is representative vibration control device.

• Steel and Composite Structures
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• 제49권5호
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• pp.487-502
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• 2023

In the realm of nanotechnology, the nonlocal strain gradient theory takes center stage as it scrutinizes the behavior of spinning cantilever nanobeams and nanotubes, pivotal components supporting various mechanical movements in sport structures. The dynamics of these structures have sparked debates within the scientific community, with some contending that nonlocal cantilever models fail to predict dynamic softening, while others propose that they can indeed exhibit stiffness softening characteristics. To address these disparities, this paper investigates the dynamic response of a nonlocal cantilever cylindrical beam under the influence of external discontinuous dynamic loads. The study employs four distinct models: the Euler-Bernoulli beam model, Timoshenko beam model, higher-order beam model, and a novel higher-order tube model. These models account for the effects of functionally graded materials (FGMs) in the radial tube direction, giving rise to nanotubes with varying properties. The Hamilton principle is employed to formulate the governing differential equations and precise boundary conditions. These equations are subsequently solved using the generalized differential quadrature element technique (GDQEM). This research not only advances our understanding of the dynamic behavior of nanotubes but also reveals the intriguing phenomena of both hardening and softening in the nonlocal parameter within cantilever nanostructures. Moreover, the findings hold promise for practical applications, including drug delivery, where the controlled vibrations of nanotubes can enhance the precision and efficiency of medication transport within the human body. By exploring the multifaceted characteristics of nanotubes, this study not only contributes to the design and manufacturing of rotating nanostructures but also offers insights into their potential role in revolutionizing drug delivery systems.

• 대한의용생체공학회:의공학회지
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• 제26권5호
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• pp.283-294
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• 2005

The Center for Imaging Human Structures (CIH) was established in December 2002 to develop new diagnostic imaging techniques and to make them available to the greater community of biomedical and clinical researchers at Sungkyunkwan University. CIH has been involved in 5 specific activities to provide solutions for early diagnosis and improved treatment of human diseases. The five area goals include: 1) development of a digital mammography system with computer aided diagnosis (CAD); 2) development of digital radiological imaging techniques; 3) development of unified medical solutions using 3D image fusion; 4) development of multi-purpose digital endoscopy; and, 5) evaluation of new imaging systems for clinical application

• 한국공간구조학회논문집
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• 제16권4호
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• pp.91-100
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• 2016

A retractable-roof spatial structure is frequently used for a stadium and sports hall. A retractable-roof spatial structure allows natural lighting, ventilation, optimal conditions for grass growth with opened roof. It can also protects users against various weather conditions and give optimal circumstances for different activities. Dynamic characteristics of a retractable-roof spatial structure is changed based on opened or closed roof condition. A tuned mass damper (TMD) is widely used to reduce seismic responses of a structure. When a TMD is properly tuned, its control performance is excellent. Opened or closed roof condition causes dynamic characteristics variation of a retractable-roof spatial structure resulting in off-tuning. This dynamic characteristics variation was investigated. Control performance of a passive TMD and a smart TMD were evaluated under off-tuning condition.

• Advances in nano research
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• 제14권3호
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• pp.235-246
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• 2023

Nanotechnology, like any other revolutionary innovation in materials science, has significantly influenced the level of competition in sports. Nanotechnology provides various benefits and enormous potential to enhance athletic equipment, making players safer, more comfortable, and more agile. Various sporting equipment is being infused with nanomaterials, including carbon nanotubes (CNTs), silica nanoparticles (SNPs), nanoclays fullerenes, etc., to enhance athlete and equipment performance. Each of these nanomaterials gives athletic equipment an extra benefit like high strength and stiffness, longevity, decreased weight, abrasion resistance, etc. This paper mechanically analysis the structural strength of tennis equipment to avoid injury. As a result, the bending forces are applied to the reinforced structures to investigate their durability.

• 한국항해항만학회지
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• 제32권8호
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• pp.645-652
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• 2008

주 5일 근무제가 확대되어 국민의 여가시간이 증가되고 소득수준이 향상됨에 따라 해양레저스포츠에 대한 국민들의 관심이 높아지고 있다. 지자체들도 해양레저스포츠 관련 전시회, 국제요트대회 등을 개최하고 대규모 투자를 추진하고 있다. 그러나 우리나라는 선진국의 수요패턴과 달리 수요가 크게 늘어나지 않고 있다. 본 연구에서는 해양레저스포츠에 대한 일반인들의 인식과 사용자들의 이용실태를 통계적으로 조사 및 분석하고 저해요인을 고찰하여 활성화를 위한 정책을 도출하였다. 결론적으로 본 연구를 통하여 해양레저스포츠의 활성화를 위해서는 일반인들의 인식을 개선하면서 법과 제도를 정비하고 인프라를 구축하며 기술개발 등을 체계적으로 추진하는 정책과제의 필요성을 확인할 수 있었다. 본 연구의 결과는 정부의 관련 정책과 사업자들의 사업계획 수립에 유용한 자료를 제공함으로써 투자의 리스크를 최소화하고 궁극적으로 해양레저스포츠의 활성화에 기여할 수 있을 것으로 평가된다.

• 대한정형외과스포츠의학회지
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• 제2권2호
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• pp.86-91
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• 2003

인대는 인체의 관절 주위에서 기능학적으로 매우 중요한 역할을 한다 인대의 기계적 성상과 손상 기전에 대한 많은 연구가 지금까지 진행되고 있으며, 많은 치료 방법들이 발달되어 사용되어 지고 있으나 치유의 질적 면이나 치유 촉진 및 완전한 치유에 대한 의문점들이 아직 도 남아있다. 관절의 기능에 중요한 역할을 하는 인대의 치유에 대한 연구와 이해를 하여 저자들은 인대의 조직학적 특성과 기계적 성상, 치유 과정 등에 관하여 여러 문헌들을 고찰하여 이 연구에서 알아보고자 한다

• 대한정형외과스포츠의학회지
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• 제2권2호
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• pp.119-126
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• 2003

Overhead athletes에서 특히 자주 볼 수 있는 불안정성 SLAP 병변, Internal impingement, 회전근 개 병변 등의 질환은 개별적으로 나타나는 것이 아니라 여러 질환이 동반되어 나타나므로 진단이나 치료에 어려움이 많다. 어깨 관절 손상의 성공적인 치료 및 운동으로의 복귀를 위하여는 각각의 운동의 생역학적인 측면과 개개의 질환의 증상 및 정확한 진단, 병리기전에 대한 확실한 이해가 선행되어야한다.