• Journal of Chest Surgery
• /
• v.53 no.6
• /
• pp.417-419
• /
• 2020

Surgeons avoid creating arteriovenous fistulae in obese patients owing to deep vessels, cannulation complications, and inconsistent outcomes. We describe placing an arteriovenous polytetrafluoroethylene (PTFE) graft between the brachial artery and axillary vein to avoid these complications. A 39-year-old super-obese woman with end-stage renal disease had undergone several hemodialysis access procedures on both arms. We traced the course of the arteriovenous graft course with the patient sitting and lying down. The ideal course was more accurate with the patient sitting; thus, the patient sat when the course was drawn, before lying on the operating bed. The PTFE graft was placed between the right brachial artery and axillary vein, according to the course in the opposite arm. No anastomotic dehiscence or pseudoaneurysm has taken place during 2 years of follow-up. In super-obese patients, the ideal course for arteriovenous grafts should be drawn while they are sitting, avoiding skin folds. This tip could avoid anastomotic dehiscence and pseudoaneurysm between the axillary vein and a PTFE graft.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.10 no.4
• /
• pp.216-222
• /
• 2002

Brake Moan is a laud and strong noise occurring at any vehicle speed over 2 mph as a low frequency in below 600Hz. In this study, we targeted to shift the unstable mode that causes the brake moan from the moats frequency range to sufficiently higher frequency range to avoid the moan phenomenon. We simulated the finite element model and found out the nodes in which the brake moan occurs the most and we regarded the boundary and its relationship between the brake pad and the rotor as a spring coefficient k. With the binary set of the spring coefficient k, we finally used genetic algorithm (GA) to get the optimal topology of the brake pad and its shape to avoid the brake moan. The final result remarkably shows that genetic algorithm can be used in topology optimization procedures requiring complex eigenvalue problems.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.9
• /
• pp.1761-1766
• /
• 2011

This paper presents obstacle avoidance of Leader-Follower formation. The follower robot maintain the formation with leader robot and avoid the detected obstacle. When obstacle is detected, follower robot avoid it considering leader robot and follower robot position and follower robot and obstacle position. In addition, follower robot avoid obstacle irrespective of obstacle size. Controller of follower robot is designed to satisfy Lyapunov stability by backstepping method. Simulation results shows that the designed controller has a stable performance.

• Journal of Institute of Control, Robotics and Systems
• /
• v.17 no.12
• /
• pp.1227-1233
• /
• 2011

An effective method of obstacle avoidance for omni-directional mobile robots is proposed to avoid moving obstacles in dynamic environments. Our method uses the concept of circle lists which represent the trajectories of robot and obstacles. This method predicts not only collision position but also collision time, and hence it enables the robot avoiding the most urgent collision first. In order to avoid obstacles, our method uses artificial repulsive force and contraction force. Simulation results show that the robot could avoid obstacles effectively.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.20 no.1
• /
• pp.180-188
• /
• 1996

The stress singularity of a sharp wedge contacting a half plane can be avoided by changing the wedge shape. Shape optimization is accomplished with the geometric strain method (GSM), an optimality criterion method. Several numerical examples are provided for different materials in the wedge and half plane to avoid stress singularity neal the sharp corner of the wedge. Optimum wedge shapes are obtained and critical corner angles are compared with the angles from analytical contact mechanics. Numerical results are well matched to analytical and experimental results. It is shown that shape optimization by the geometric strain method is a useful tool to reshape the wedge and to avoid a stress singulatiry. The method applies to more general geometries where the singular behavior would be difficult to avoid by classical means.

• International Journal of Fluid Machinery and Systems
• /
• v.10 no.3
• /
• pp.296-306
• /
• 2017

Hydropower is now changing its role from the energy generator into the most powerful and reliable tool for stabilizing the electrical network, especially under the increase of intermittent power sources like wind-power and solar-power. Although the hydropower plants are the most robust generating facilities, they are not immune from unexpected severe incidents having long downtime, considerable restoration cost and sometimes fatalities. The present paper provides some study results about severe incidents in the conventional hydropower plants, mainly about the flood, fire and electro-mechanical troubles, except for the incidents of civil facilities. It also provides some possible scenarios which may lead some measures how to avoid such incidents. Finally, it provides some comprehensible recommendations to avoid severe incidents based on experiences.

• ETRI Journal
• /
• v.32 no.1
• /
• pp.44-52
• /
• 2010

Ultra-wideband (UWB) systems have witnessed a debate over whether they may cause interference to other existing and future narrowband systems sharing their band of operation. The detect and avoid (DAA) mechanism was developed as a solution to reduce interference to narrowband systems in order to ease regulatory concerns. It works by adaptively reducing the transmitted power at the overlapping bands upon detecting an active narrowband link. However, employing DAA degrades the performance of UWB transmissions. In this paper, we present the Korean UWB regulations as an example of regulations that require DAA in certain bands. We investigate DAA's impact on performance and propose a method to mitigate it, which provides UWB with the more efficient support of the DAA mechanism and enables it to avoid a larger number of narrowband users while sustaining the data rate. Results show significant improvement in performance with the application of our technique compared to conventional performance.

• International conference on construction engineering and project management
• /
• 2005.10a
• /
• pp.709-713
• /
• 2005

The conflict problems encountered in the construction projects led to prolonged delays in implementation, interruptions and sometimes suspension. This paper has described ten fundamental management principles to avoid conflicts in construction field and increase the productivity. They are: i) hire good (not cheap) construction professionals ii) set reasonable time and cost goals iii) recognize contractors and designers are in business to make profit iv) draft a clear contract document v) pick a suitable project delivery system vi) implement a front-end approach vii) accept construction project as a dynamic process viii) need of education and training of professionals ix) accountability and teamwork in construction site, and x) avoid negligence.

• International Journal of Advanced Culture Technology
• /
• v.12 no.2
• /
• pp.180-189
• /
• 2024

We aimed to see if approach-avoidance visual experience would have different effects in the valence rating of emojis. Previous literature has shown that approach-avoidance tendencies have influences people's emotional perceptions. Up until now, research on emojis have been heavily focused on static emojis, which gives room for exploration whether if movement added on to emoji would elicit different emotional responses. In the study, we examined the impact of approach-avoidance visual experience of emojis via mobile interface, categorized into 4 experimental conditions (positive approach, negative approach, positive avoid, and negative avoid), and conducted semi-structured interviews to identify users' reasonings towards their valence ratings on specific emojis with approach or avoid movements. We found that positive approach emojis were the highest valence rating and preferred by the participants, while there were no differences between negative emoji approach or avoidance. Based on these findings, we conclude that positive emojis could be intensified to be more positive with approach motion, yet for negative emojis, individual differences or contextual differences may arise in its emotional ratings.

• Korean Journal of Computational Design and Engineering
• /
• v.2 no.4
• /
• pp.215-221
• /
• 1997

A new approach in solving design centering problem is presented. Like most stochastic optimization problems, optimal design centering problems have intrinsic difficulties in multivariate intergration of probability density functions. In order to avoid to avoid those difficulties, genetic algorithm and very coarse Monte Carlo simulation are used in this research. The new algorithm performs robustly while producing improved yields. This result implies that the combination of robust optimization methods and approximated simulation schemes would give promising ways for many stochastic optimizations which are inappropriate for mathematical programming.