• Journal of Chest Surgery
• /
• v.54 no.4
• /
• pp.263-265
• /
• 2021

Intraoperative events can occur during video-assisted thoracoscopic surgery (VATS) lobectomy due to unfavorable surgical anatomy, such as dense adhesions or calcifications around the pulmonary arteries. Troubleshooting intraoperative complications is essential for performing safe and successful VATS pulmonary resection and lymph node dissection. If continuous bleeding occurs or VATS does not proceed despite all measures, conversion to open thoracotomy should not be delayed.

• Journal of Chest Surgery
• /
• v.54 no.4
• /
• pp.310-313
• /
• 2021

There are several types of minimally invasive approaches for thymectomy, of which the transpleural approach by video-assisted thoracoscopic surgery is particularly useful. In this approach, thymectomy is performed from either side of the thoracic cage. Thoracic surgeons should be familiar with the principles of the procedure, the anatomy of the region, and surgical strategies for successful thymectomy. The details of transpleural thymectomy are discussed herein.

• Journal of Chest Surgery
• /
• v.54 no.4
• /
• pp.286-293
• /
• 2021

The extracorporeal anastomosis technique for video-assisted thoracoscopic surgery (VATS) intrathoracic esophagogastric anastomosis is a convenient, easy technique to use in VATS esophagectomy. The surgeon can assess the viability and the status of the gastric conduit, and the introduction of a circular stapler can be easily done under direct vision extracorporeally, enabling easy and simple VATS intrathoracic anastomosis between the esophagus and the gastric conduit.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• v.5B no.2
• /
• pp.111-117
• /
• 2005

Several of the conventional hydraulic systems in an automobile are now being replaced by more reliable and energy efficient electromechanical systems. Developments in the brushless permanent magnet machine and in the power and control electronics are the key factors responsible for this transformation. These applications brought out some performance challenges associated with the brushless machines. This paper will focus on these challenges to be able to use these machines in such applications. In terms of replacing hydraulic systems with electromechanical systems, steering system is leading the way in automobiles. Currently, steering systems using Electro-hydraulically assisted systems and Electrically assisted (Electromechanical) systems are in the market. Though the Electrically assisted power steering has several advantages over other systems, certain performance and cost challenges delayed the penetration of such systems in to the market.

• Corrosion Science and Technology
• /
• v.7 no.2
• /
• pp.77-84
• /
• 2008

Based upon the good compatibility to neutron irradiation and high temperature water environment, austenitic stainless steels are widely used for core internal structural materials of light water reactors. But, recently, intergranular cracking was detected in the stainless steels for the core applications in some commercial PWR plants. Authors studied on the root cause of the intergranular cracking and developed the countermeasure including the alternative materials for these core applications. The intergranular cracking in these core applications are defined as an irradiation assisted mechanical cracking and irradiation assisted stress corrosion cracking. In this paper, the root cause of the intergranular cracking and its countermeasure are summarized and discussed.

• Carbon letters
• /
• v.17 no.1
• /
• pp.1-10
• /
• 2016

Lignocellulosic biomass conversion to biofuels such as ethanol and other value-added bio-products including activated carbons has attracted much attention. The development of an efficient, cost-effective, and eco-friendly pretreatment process is a major challenge in lignocellulosic biomass to biofuel conversion. Although several modern pretreatment technologies have been introduced, few promising technologies have been reported. Microwave irradiation or microwave-assisted methods (physical and chemical) for pretreatment (disintegration) of biomass have been gaining popularity over the last few years owing to their high heating efficiency, lower energy requirements, and easy operation. Acid and alkali pretreatments assisted by microwave heating meanwhile have been widely used for different types of lignocellulosic biomass conversion. Additional advantages of microwave-based pretreatments include faster treatment time, selective processing, instantaneous control, and acceleration of the reaction rate. The present review provides insights into the current research and advantages of using microwave-assisted pretreatment technologies for the conversion of lignocellulosic biomass to fermentable sugars in the process of cellulosic ethanol production.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.8 no.4
• /
• pp.141-148
• /
• 2000

As the steel plates used for automobile safety the TRIP-assisted multiphase steels are being introduced to automobile industry with respect to their remarkable mechanical properties for the combination of high strength and large elongation. This multiphase structure is generated by two stage heat treatment (intercritical annealing & isothermal treatment) The metastable retained austenite can be transformed to martensite when plastically deformed which results in TRIP effect. Actually the microstructure of TRIP-assisted steels consist of a fine dispersite. There present discussion deals with bainite reaction kinetics of austenite in the process o f two stage heat treatment. In relation to bainite transformation the characteristics of bainite reaction is found to be influenced by the bainite tempering temperature and also by the relative rate in which carbides precipitate within residual austenite.

• Journal of the Korean Society for Precision Engineering
• /
• v.17 no.10
• /
• pp.102-109
• /
• 2000

In the present study, gas-assisted molding and structural vibration analysis of hollow long cylinder with the variation of gas injection pressure are performed. Though there are so many parameters such as delay time, injection pressure, and gas pressure on gas-assisted molding, the latter has the most dominant effect on this process. Therefore, the present paper deals with the effects of gas pressure on the dynamic stiffness of the model by means of vibration analysis and then suggests the fundamental materials which can be directly adapted to manufacturing lines.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.8
• /
• pp.3360-3365
• /
• 2011

This paper deals with method to measure the user's driving-will force and to control the power-assisted wheelchair. To solve this problem, we extract the user's driving-will by using the mathematical motor model. And then, we get the linear and angular velocity at the center of the vehicle. Wheel velocities are also measured from center velocity. Finally, power-assisted electric wheelchairs are controlled by these data. Here all processes are verified by simulation.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.43-47
• /
• 1995

The ball screw is one of the important mechanical parts for the linear motion feeding systems. The usage of the ball screw has been growing in various industrial fields such as CNC machine tool, industrial robot and automated systems. Because of ever increasing demand for ball screws, increased accuracy and quality of the ball screw is needed,especially the surface roughness of the ball contact area in order to diminish noise and vibration. Therefore to improve the surface roughness of the area,we introduced magnetic assisted polishing which is one of the new potential polishing methods. In this study, diamond slurry and iron powder was used for magnetic assisted polishing of the ball bearing surface. This polishing process was experimentally confirmed to improve the surface roughness of the ball bearing.