• Structural Monitoring and Maintenance
• /
• v.10 no.1
• /
• pp.63-86
• /
• 2023

Structural health monitoring and damage detection are essential for assessing, maintaining, and rehabilitating structures. Most of the existing damage detection approaches compare the current state structural response with the undamaged vibrational structural response, which is unsuitable for old and existing structures where undamaged vibrational responses are absent. One of the approaches for existing structures, numerical model updating/inverse modelling, available in the literature, is limited to numerical studies with high-end software. In this study, an attempt is made to study the effectiveness of the model updating technique, simplify modelling complexity, and economize its usability. The optimization-based detection problem is addressed by using programmable open-sourced code, OpenSees^® and a derivative-free optimization code, NOMAD^®. Modal analysis is used for damage identification of beam-like structures with several damage scenarios. The performance of the proposed methodology is validated both numerically and experimentally. The proposed method performs satisfactorily in identifying both locations and intensity of damage in structures.

• Clinics in Shoulder and Elbow
• /
• v.19 no.2
• /
• pp.60-66
• /
• 2016

Background: Management of massive rotator cuff tears can be challenging because of the less satisfactory results and a higher retear rate regardless of the use of open or arthroscopic repair technique. Methods: We retrospectively analyzed 102 cases of massive rotator cuff tear treated with either open or arthroscopic repair. Open repair was performed in 38 patients; and arthroscopic repair, in 64 patients. The mean age at the time of surgery was 59.7 years in the open group and 57.6 years in the arthroscopic group. Results: The Constant score increased from the preoperative mean of 55.9 to 73.2 at the last follow-up in the open repair group and from 53.8 to 67.6 in the arthroscopic repair group (p<0.001 and <0.001, respectively). The University of California at Los Angeles (UCLA) score increased from a preoperative mean of 17.7 to 30.8 at the last follow-up in the open group and from 17.5 to 28.7 in the arthroscopic group (p<0.001 and <0.001, respectively). No statistically significant difference in the Constant and UCLA scores was observed between the two groups at the last follow-up (p=0.128 and 0.087, respectively). Retear was found in 14 patients (36.8%) in the open group and 39 patients (60.9%) in the arthroscopic group (p=0.024). Conclusions: Open and arthroscopic repairs of massive rotator cuff tears may provide satisfactory clinical results with no significant difference. However, a significantly lower retear rate was observed for the open repair group compared with the arthroscopic repair group.

• The Journal of Korean Academy of Prosthodontics
• /
• v.57 no.2
• /
• pp.195-202
• /
• 2019

At the department of prosthodontics, the elderly patients with severely atrophied alveolar ridge who have been wearing complete dentures for a long period frequently visit the clinic. In general, the open-mouth impression technique for manufacturing a mandibular complete denture to secure primary support on buccal shelf area has been prevalent. In addition, for securing retention and stability of mandibular denture, we should consider diagnosis, oral function, denture border, occlusal plane, teeth arrangement, and patient training, etc.. But in edentulous patients with severe alveolar bone atrophy, it may hardly secure retention and stability of mandibular complete denture. To promote these, some of clinicians are making an attempt manufacturing the mandibular complete dentures using closed-mouth impression technique based on several reports that compare various impression techniques including open-mouth and closed-mouth impression technique. This case report suggests closed-mouth impression technique may promote retention and stability of mandibular complete denture and compares between the two impression techniques clinically.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.32 no.1
• /
• pp.43-48
• /
• 2010

The mandibular condyle fracture occurs at 15-30% frequency of whole mandibular fracture. The treatment of choice is open reduction or closed reduction. In many cases, closed reduction is preferred for treatment of condylar fracture because it is hard to approach to condyle and there is risk of surgical complications, such as nerve damage in open reduction. Open reduction, however, has some advantages like possibility of anatomical reduction, occlusal stability and rapid functional recovery. Furthermore, it is possible to retain original ramal heights and to decrease deviation during mouth opening. There are many surgical approaches for open reduction of subcondyle fracture. At present, transoral approach using trochar device is tried for effective and minimally invasive method for open reduction of subcondyle fracture. And the authors report the cases of reduction of subcondyle fracture with transoral approach using trochar device.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2010.11a
• /
• pp.1784-1787
• /
• 2010

General Purpose Graphic Processing Unit (GPGPU) computing is a technique that utilizes the high-performance many-core processors of high-end graphic cards for general-purpose computations such as 3D graphics, video/image processing, computer vision, scientific computing, HPC and many more. GPGPUs offer a vast amount of raw computing power, but programming is extremely challenging because of hardware idiosyncrasies. The open computing language (OpenCL) has been proposed as a vendor-independent GPGPU programming interface. OpenCL is very close to the hardware and thus does little to increase GPGPU programmability. In this paper we present how a set of digital camera image signal processing (ISP) filters can be realized efficiently on GPGPUs using OpenCL. Although we found ISP filters to be memory-bound computations, our GPGPU implementations achieve speedups of up to a factor of 64.8 over their sequential counterparts. On GPGPUs, our proposed optimizations achieved speedups between 145% and 275% over their baseline GPGPU implementations. Our experiments have been conducted on a Geforce GTX 275; because of OpenCL we expect our optimizations to be applicable to other architectures as well.

• Journal of Chest Surgery
• /
• v.20 no.2
• /
• pp.270-280
• /
• 1987

One hundred thirteen cases of open heart surgery were performed in the department of thoracic and cardiovascular surgery of Inha General Hospital from April 1986 to April 1987. There were 73 cases of congenital heart disease and 40 cases of acquired valvular heart disease, including one redo case respectively. The technique of deep hypothermia with circulatory arrest was used widespreadly for infants and small children, and early extubation was performed as possible in the great number of all cases. There were three operative deaths [2.7%], all in congenital cases, and three follow-up deaths, all in acquired cases.

• Journal of Chest Surgery
• /
• v.21 no.2
• /
• pp.366-372
• /
• 1988

Cardiac tamponade occurring after open heart surgery is a rare, but fatal complication necessitating urgent drainage, though postoperative pericardial effusion is common. Two-dimensional echocardiographic study provides excellent postoperative visualization of pericardial effusion. Catheter insertion guided by two-dimensional echocardiography has been used to accomplish nonoperative drainage of symptomatic postoperative pericardial effusion in 4 cases. This technique offers simplicity, safety, and cost effectiveness.

• The Academic Congress of Korean Shoulder and Elbow Society
• /
• 2003.03a
• /
• pp.24-24
• /
• 2003

• Archives of Plastic Surgery
• /
• v.41 no.1
• /
• pp.71-76
• /
• 2014

Background Numerous methods exist for simultaneous correction of mild blepharoptosis during double eyelid surgery. These methods are generally categorized into either incisional (open) or non-incisional (suture) methods. The incisional method is commonly used for the creation of the double eyelid crease in patients with excessive or thick skin. However, concurrent open ptosis correction is often marred by the lengthy period of intraoperative adjustment, causing more swelling, a longer recovery time, and an increased risk of postoperative complications. Methods The authors have devised a new, minimally invasive technique to alleviate mild ptosis during incisional double eyelid surgery. The anterior lamella is approached through the incisional technique for the creation of a double eyelid while the posterior lamella, including Muller's and levator muscles, is approached with the suture method for Muller's plication and ptosis correction. Results The procedure described was utilized in 28 patients from June 2012 to August 2012. Postoperative asymmetry was noted in one patient who had severe preoperative conjunctival scarring. Otherwise, ptosis was corrected as planned in the rest of the cases and all of the patients were satisfied with their postoperative appearance and experienced no complications. Conclusions Our hybrid technique combines the benefits of both the incisional and suture methods, allowing for a predictable and easily reproducible correction of blepharoptosis with an aesthetically pleasing double eyelid.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.271-272
• /
• 2006

This paper presented a new experimental gain tuning technique for a Multi-Axis Servo System. First, the investigation for proportional gain of velocity control loop by using a Dynamic Signal Analyzer (DSA) was performed. Using the FUNCTION characteristic of DSA based on the Bode plot, the Bode plot of open loop transfer function was obtained. In turn, the integral gain of a servo controller can be found out by using the Integration time constant extracted from the Bode plot of open loop transfer function. In the meanwhile, the positional gain of the servo controller has been obtained by using the Bode plot of the closed loop transfer function. We have also proposed the technique to find out an optimal parameter of a notch filter, which has a great influence on vibration reduction, by using the damping factor extracted from the Bode plot of closed loop transfer function.