• Journal of Korean Neurosurgical Society
• /
• 제45권6호
• /
• pp.378-380
• /
• 2009

Osteoporotic patients who undergo percutaneous vertebroplasty (PVP) have the risk of a repeated collapse of their adjacent vertebral body due to alteration of load transfer into the adjacent vertebral body. The authors have experienced a rare case of repeated osteoporotic vertebral compression fractures (VCF) resulting in extreme multi-level PVP. A 74-year-old female developed severe back pain after slipping down one month ago. Her X-ray and MR images indicated a T11 VCF. She underwent successful PVP with polymethylmethacrylate (PMMA). Two weeks later, she returned to our hospital due to a similar back pain. Repeated X-ray and MR images showed an adjacent VCF on T12. A retrial of PVP was performed on T12, which provided immediate pain relief. Since then, repeated collapses of the vertebral body occurred 12 times in 13 levels within a 24-month period. Each time the woman was admitted to our hospital, she was diagnosed of newly developed VCFs and underwent repeated PVPs with PMMA, which finally eased back pain. Based on our experience with this patient, repeated multiple PVP is not dangerous because its few and minor complications. Therefore, repeated PVP can serve as an effective treatment modality for extreme-multi level VCFs.

• 한국기계가공학회지
• /
• 제18권2호
• /
• pp.102-107
• /
• 2019

The vehicle market has developed environment-friendly vehicles to comply with fuel economy regulations and exhaust regulations that have become stricter and stricter over time. Many studies have been conducted to improve the travel performance and fuel economy of environment-friendly vehicles, and vehicle manufacturers have been studying how to manufacture light-weight vehicles in order to improve the fuel economy of both existing vehicles and the newer environment-friendly vehicles. Exemplary light-weight vehicle technologies optimizes the design of the vehicle body structure, which is a vehicle weight-reducing method that modifies component shapes or layouts to optimize the structure of the vehicle. In addition, the new process technology uses new light-weight and very strong materials, and not typical materials, to manufacture light-weight vehicles. This study aims at the optimal design of vehicle body structures using multi-materials for the Fender-Apron, which is an important frame member for the external front side of a vehicle body, by conducting FEA (Finite Element Analysis) and multi-material bonding.

• Nuclear Engineering and Technology
• /
• 제55권11호
• /
• pp.4125-4133
• /
• 2023

The transportation of spent nuclear fuel is an important process that involves road and sea transport from an interim storage facility to storage and final disposal sites. As spent nuclear fuel poses a significant risk, carefully evaluating its vibration and shock characteristics under normal transport conditions is essential. In this regard, full-scale multi-modal transport tests (MMTT) have been conducted domestically and internationally. In this paper, we discuss the process of developing a multi-body dynamics (MBD) model to analytically simulate conditions that cannot be considered in tests. The MBD model is based on the KORAD-21 transportation system was validated using the Korean MMTT results from 2020 to 2021. This paper summarizes the details of the development and verification of the MBD model for the KORAD-21 transportation system under normal transport test conditions. This approach can be applicable to various transportation scenarios and systems, and the results of this study will help to ensure that nuclear fuel transportation is conducted safely and effectively.

• 복식
• /
• 제51권7호
• /
• pp.21-33
• /
• 2001

The purpose of this study is to Investigate the value of multi-culture and to examine how multi-culture has been reflected in men's fashion. As for the research methodology, literary research was under taken to study psychoanalytical and socioeconomic contexts in which multi-culture in men's fashion has been formed. In addition, demonstrative studies on styles were undertaken through the analysis of pictures and photos. The historical range of this study is from the 19th century when western and modern original form of men's dress were visualized, to the year 2001 when the elements of multi-culture are expressed in men's fashion. Westerners in 19th century respected Greek fine arts and the desire for realistic restoration of the body of Greek hero is well reflected in men's suits. Other races were forced to believe such realistic depiction of the Greek body as a symbol of modernization. With the advent of the Information Society In the late 20th century, absolute power had been decentralized, and people in the third world have revealed the racial contradictions by realizing the concept of splitted subject existing In unconscious. In the post-colonial world in the late 20th century, the value of diverse cultures is admitted. Models come from various races in fine art or photographic work Fashion trends are no longer limited to dominant mode, and designers express multi-culture by adopting and renewing folk elements from all over the world.

• 한국소음진동공학회논문집
• /
• 제25권3호
• /
• pp.169-175
• /
• 2015

This study aims to improve the dynamic stiffness of an inspection robot frame to prevent derailment from transmission lines. Finite element models for the transmission lines and robot frame are developed for the multi-body dynamic simulation. Natural frequency analysis was conducted using the FE models. Three types of spacer damper clamps installed on 4-conductor transmission lines are used to evaluate the derailment of the robot. Multi-body dynamic simulations with FE models are demonstrated for sub-span oscillation. When the robot operates, derailment of inspection robot from the transmission lines is determined because of resonance. To prevent the resonance, body position was changed and thickness optimization was conducted. The results show that derailment was not occurred because of the natural frequency improvement.

• 제어로봇시스템학회논문지
• /
• 제14권11호
• /
• pp.1146-1154
• /
• 2008

This paper presents a method for the acceleration analysis of multi-legged walking robots in consideration of the frictional ground contact. This method is based on both unified dynamic equation for finding the acceleration of a robot's body and constraint equation for satisfying no-slip condition. After the dynamic equation representing relationship between actuator torques and body acceleration, is derived from the force and acceleration relationship between foot and body's gravity center, the constraint equation is formulated to reconfigure the maximum torque boundaries satisfying no-slip condition from given original actuator torque boundaries. From application of the reconfigured torques to the dynamic equation, interested acceleration boundaries are obtained. The approach based on above two equations, is adapted to the changes of degree-of-freedoms of legs as well as friction of ground. And the method provides the maximum translational and rotational acceleration boundaries of body's center that are achievable in every direction without occurring slipping at the contact points or saturating all actuators. Given the torque limits in infinite normsense, the resultant accelerations are derived as a polytope. From the proposed method, we obtained achievable acceleration boundaries of 4-legged and 6-legged walking robot system successfully.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제7권8호
• /
• pp.1805-1824
• /
• 2013

Recently, the use of wireless body area networks (WBAN) has been increasing rapidly in medical healthcare applications. WBANs consist of smart nodes that can be used to sense and transmit vital data such as heart rate, temperature and ECG from a human body to a medical centre. WBANs depend on limited resources such as energy and bandwidth. In order to utilise these resources efficiently, a very well organized medium access control (MAC) protocol must be considered. In this paper, a new, adaptive and energy-efficient MAC protocol, entitled isMAC, is proposed for WBANs. The proposed MAC is based on multi-channel communication and aims to prolong the network lifetime by effectively employing (i) a collision prevention mechanism, (ii) a coordinator node (WCN) selection algorithm and (iii) a transmission power adjustment approach. The isMAC protocol has been developed and modelled, by using OPNET Modeler simulation software. It is based on a networking scenario that requires especially high data rates such as ECG, for performance evaluation purposes. Packet delay, network throughput and energy consumption have been chosen as performance metrics. The comparison between the simulation results of isMAC and classical IEEE 802.15.4 (ZigBee) protocol shows that isMAC significantly outperforms IEEE 802.15.4 in terms of packet delay, throughput and energy consumption.

• 대한조선학회논문집
• /
• 제58권1호
• /
• pp.24-31
• /
• 2021

In this study, we present experimental observations of artificial supercavitation generated by the injection of compressed air at multiple locations on the body. Experiments were conducted at a cavitation tunnel equipped with a special facility to remove injected air before returning to the test section. Artificial supercavitation, which is generated at a relatively low speed compared to natural supercavitation, is formed asymmetrically on the axis of the body due to the buoyancy effect. In order to accelerate the development of the supercavity and increase the area covering the body, an experimental device capable of additional injection from the body was designed and its performance was evaluated through the model test. The shapes of the supercavity generated by multi-injections of different combinations according to different flow speeds were analyzed using high-speed shadow images. The results show that multiple injections at suitable locations can effectively increase the length of the supercavity and consequently improve propulsion efficiency.

• 한국의류산업학회지
• /
• 제11권6호
• /
• pp.867-877
• /
• 2009

These days, the fantastic in opposition to classic beauty becomes a genre of creative body expression. The purpose of this study was to analyze the expressive characteristics of body types and meanings in recent fantastic fashion illustration. The method of this study was to analyze recent documentaries, fashion books, internet web site and so forth. The results were as follows: In literatures, pictures and movies, the category of the fantastic body's expressive types were classified as dominant mutant based on SF, multi body or fragment body by disruption, heterogeneous compound based on myth, personified humanoid and non substance in supernatural boundary. The dominant mutant based on SF was expressed image morphing, composition of machine image with body and modern metamorphosis of classic SF body. It means propensity to post-feminism and reservation of meaning analysis based on human unconsciousness. The multi body or fragment body by disruption in fashion illustration was expressed distorted composition of same body pictures, replacement of different bodies, deconstruction and partial omission of body and composition of meaning or non meaning images. It means permanence of self and basic narcissism. The heterogeneous compound based on myth was expressed general composition or optical illusion of various and aggressive animal motive. It means reinterpretation of original myth, metaphor of basic femme fatale, pursuit of permanence and sign of primitive mind in unconsciousness. The personified humanoid was expressed real human body description of mannequin or ball joint doll and anthropomorphism of robot image. It means representative satisfaction and nostalgia of childhood. The non substance in supernatural boundary was expressed grotesque description of ghost, zombie, vampire, angel, fairy, using of symbolic red, black color and non body. It means human's basic desire about immortality and taboo. Through the result of these study, the expression of fantastic body in fashion illustration will expend expressive method and we will understand human and cultural codes of today.

• 한국해양공학회지
• /
• 제20권5호
• /
• pp.15-22
• /
• 2006

A finite-volume method using multi-block grid technique has been developed in order to investigate the flow field around multi-body. Here the matching grids are used at the interface between blocks and the boundary conditions are imposed there to exchange physical values across the interface. For the test problems, the laminar viscous flaw around one-and two-cylinder are simulated and the results are compared with experiments and other numerical results.