Sungkyu Cho

We have proposed and fabricated a maximum power point tracking (MPPT) circuit for thermoelectric generator (TEG) without digital controller unit. The experimental and simulation results from the proposed MPPT circuit employing the boost cascaded-with-buck converter dealt with rapid variation of temperature and abrupt changes of load current have shown that the proposed method allows stable operation with high power transfer efficiency. The main advantage of proposed method is analog tracking cir

The 16-mm polytetrafluoroethylene conduit for ECFP showed acceptable outcomes and good haemodynamic status in small-sized patients. According to our results, small patients do not require large conduits to accommodate their growth potential.

MV repair in paediatric patients with congenital mitral stenosis showed acceptable results. The follow-up echocardiogram also revealed satisfactory results. Close follow-up is necessary to detect the development of postoperative mitral stenosis or regurgitation.

CoA repair in adolescents and adults showed good outcomes. Left subclavian artery to descending aorta bypass grafting is safe and effective for managing CoA in adolescents and adults.

Background: With the advances of cardiac surgery, the demand for an artificial prosthesis has increased, and this has led to the development and utilization of diverse alternative materials. We conducted this research to improve an artificial prosthesis by examining the changes of the physical qualities, the pressure related tensile strength, the change in elasticity and the thermostability of a xenograft valve (porcine) and pericardium (bovine, porcine) based on the type of fixation liquid we u

In infants <5 kg, TVD can be a reasonable and valid option for successful VSD closure without morbidities, including TR progression if the indication exists.

Software is completely exposed to an attacker after it is distributed because reverse engineering is widely known. To protect software, techniques against reverse engineering are necessary. A code encryption scheme is one of the techniques. A code encryption scheme encrypts the binary executable code. Key management is the most important part of the code encryption scheme. However, previous schemes had problems with key management. In an effort to solve these problems in this paper, we survey th

Abstract Network reprogramming is a process used to update program codes of sensor nodes that are already deployed. To deal with potentially unstable link conditions of wireless sensor networks, the epidemic approach based on 3‐way advertise‐request‐data handshaking is preferred for network reprogramming. Existing epidemic protocols, however, require a long completion period and high traffic overhead in high‐density networks, mainly due to the hidden terminal problem. In this paper, we address t

Despite the improvement of transvenous leads, the open surgical implantation of epicardial leads in neonates and infants remains essential.