• Proceedings of the KWS Conference
• /
• 2007.11a
• /
• pp.73-75
• /
• 2007

The resistance spot weld is among the most common automotive weld method, now a constant current type is the most common used types. A constant current type have a weak point which can not deal with a defect occurrence by external factors, and recently the adaptive resistance spot weld have been applied around the advanced automotive company. This technology can maintain a stable weld quality through a suitable control the current and weld time with weld environment. In this research, the adaptive resistance spot weld is applied to high strength steels, and its application possibility and weld characteristics are presented.

• Journal of Chest Surgery
• /
• v.16 no.2
• /
• pp.221-225
• /
• 1983

Morgagni, in 1760, 1st. described the findings of substernal herniation of abdominal contents into the thoracic cavity, based upon 25 postmortem dissections. Herniation through the foramen of Morgagni is the rarest occurrence of the congenital diaphragmatic hernias and is usually a few symptoms. With the increasing use of routine chest roentgenogram & the need to exclude the possibility of a mediastinal neoplasm, most such cases are brought to the attention of a surgeon. We had experienced 2 cases of Morgagni hernia, which one caused a simple mechanical intestinal obstruction & diagnosed as acute appendicitis with perforation & another one was diagnosed as mediastinal lipoma on routine chest X-ray film at arrival due to traffic accident. We had performed left paramedian abdominal incision as misdiagnosis of acute appendicitis with perforation and repair of the defect and returned transverse colon & stomach into abdominal cavity in one patient. And in another patient, we preferred to approach through right thoracotomy incision and then left upper paramedian abdominal incision and returned the omentum into the abdominal cavity. The post-operative courses were in uneventful and we report these cases and review and discuss the literatures.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2000.01a
• /
• pp.61-62
• /
• 2000

We have studied the molecular orientation by the phase transitions of the chiral smectic liquid crystals, 4-(1-Trifluoromethyl-6-ethoxy-hexyloxycarbonlphenyl)-4-nonyloxybiphenyl-4-carbo-xylate (R-TFMEOHPNBC) to seek the original solution of the zig-zag defect using two different experimental techniques; optical system and x-ray scattering. The phase sequence is gamma ferroelectric $(SmC{\gamma}\;^*)$ ${\rightarrow}$ smectic A (SmA) ${\rightarrow}$ isotropic (I). Existence of two layer spacing at chiral smectic phase gives a possibility of the molecular orientation in two different tilt angles, ${\theta}\;_1$ and ${\theta}\;_2$, which are separated each other to the layer normal at a given temperature. The gamma ferroelectric-like phase is, first, discovered in the single compound.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.54 no.2
• /
• pp.61-66
• /
• 2005

This paper presents an unified method which solves real and reactive power dispatch problems for the economic operation of power systems using evolutionary computation such as genetic algorithms(GA), evolutionary programming(EP), and evolution strategy(ES). Many conventional methods to this problem have been proposed in the past, but most of these approaches have the common defect of being caught to a local minimum solution. The proposed methods, applied to the IEEE 30-bus system, were run for 10 other exogenous parameters and composed of P-optimization module and Q-optimization module. Each simulation result, by which evolutionary computations are compared and analyzed, shows the possibility of applications of evolutionary computation to large scale power systems.

• Journal of the Korean Society of Safety
• /
• v.18 no.2
• /
• pp.6-15
• /
• 2003

A method is presented for diagnosing the converter bearings by using acoustic emission. The flaking mechanism causing the large-scale bearing for furnace to flaw is investigated and a possibility of defect is verified by Finite Element method. he diagnosis logic is proposed fir detecting the flaw of a non-continuous rotating machine. It is proved that the acoustic emission energy can be used as a representative parameter for an acoustic event. Applying the method to the tilting bearings for steel mill in operation, the effectiveness of this logic is evaluated. It is shown that AE signal is generated only when the bearing is tilting, and the trend analysis can be focused upon this process.

• Proceedings of the KIEE Conference
• /
• 2006.07c
• /
• pp.1469-1471
• /
• 2006

It is very important to discriminate noises such as air corona in measuring on-site partial discharges (PD). Therefore, in order to investigate the possibility of separating PD(partial discharge) and noises through the pulse analysis, pulse shapes measured by a resistive sensor and a HFCT were analyzed and PA(pulse analysis) were performed. For the purpose, the HFPD detection and PA system has been developed. Also void discharges and air corona were adopted as the artificial defect and noises, respectively.

• Proceedings of the KIEE Conference
• /
• 1996.07b
• /
• pp.714-716
• /
• 1996

This paper presents an optimization method for optimal reactive power dispatch which minimizes real power loss and improves voltage profile of power systems using evolutionary computation such as genetic algorithms(GAs), evolutionary programming(EP). and evolution strategy(ES). Many conventional methods to this problem have been proposed in the past, but most these approaches have the common defect of being caught to a local minimum solution. Recently, global search methods such as GAs, EP, and ES are introduced. The proposed methods were applied to the IEEE 30-bus system. Each simulation result, compared with that obtained by using a conventional gradient-based optimization method, Sequential Quadratic Programming (SQP), shows the possibility of applications of evolutionary computation to large scale power systems.

• Proceedings of the KIEE Conference
• /
• 1996.11a
• /
• pp.166-168
• /
• 1996

This paper presents an power system optimization method which solves real and reactive power dispatch problems using evolutionary computation such as genetic algorithms(GAs), evolutionary programming(EP), and evolution strategy(ES). Many conventional methods to this problem have been proposed in the past, but most these approaches have the common defect of being caught to a local minimum solution. Recently, global search methods such as GAs, EP, and ES are introduced. The proposed methods, applied to the IEEE 30-bus system, were run for 12 other exogenous parameters. Each simulation result, by which evolutionary computations are compared and analyzed, shows the possibility of applications of evolutionary computation to large scale power systems.

• Journal of Chest Surgery
• /
• v.53 no.4
• /
• pp.205-210
• /
• 2020

Esophageal anastomotic leak is the most common and serious complication following esophagectomy. However, the standard treatment for anastomotic leaks remains unclear. Recently, endoscopic vacuum therapy has become an important non-surgical alternative treatment method for patients with esophageal anastomotic leak. This treatment involves the endoscopic placement of a sponge connected to a nasogastric tube into the defect cavity or lumen. Subsequently, continuous negative pressure is delivered to the cavity through the tube. Several studies have reported a treatment success rate of 80% to 100%. In this study, we review the mechanism of action, the method of performing the procedure, its safety and efficacy, and prognostic factors for failure of endoscopic vacuum therapy in the management of patients with anastomotic leak, and on this basis attempted to confirm the possibility of establishing a standardized treatment protocol using endoscopic vacuum therapy.

• Journal of Korean Dental Science
• /
• v.16 no.2
• /
• pp.211-217
• /
• 2023

Fibrous dysplasia (FD) accompanying osteomyelitis (OM) has been reported to result in recurrent, refractory pain and swelling. Although radical resection of the lesions has been suggested, effective surgical treatment strategies have not yet been established due to the limited number of studies on this pathological condition. In this report, we present the conservative surgical management of FD accompanying OM in two patients who exhibited recurrent signs and symptoms. The present report suggests that OM occurring in patients with FD can be successfully managed with conservative surgical treatment and following removal of the odontogenic origin although bone defect in which inflammatory fibro-osseous lesions is removed through decompression surgery may exhibit regeneration of dysplastic bone. In addition, for the prevention of OM in patients with FD, careful clinical examination and thorough management of dental-related pathologies are necessary with regular follow-up examinations to screen for the possibility of malignant changes.