• Archives of Plastic Surgery
• /
• v.36 no.5
• /
• pp.555-558
• /
• 2009

Purpose: The high success rate of free flap transfers is well documented in previous literature, and is possible due to the early detection of vascular compromise and timely reoperation. We specifically analyzed the operative results of immediate and delayed reconstruction with free transverse rectus abdominis musculocutaneous(TRAM) flap respectively in order to reveal its distinctive features on timing and causes of vascular compromise. Methods: The senior author operated on 158 patients, 161 cases of free TRAM flap for breast reconstruction. 51 patients underwent delayed reconstruction, whilst immediate reconstruction was performed in the other 107 patients. All patients were monitored every 3 hours for the first 3 days. We reviewed medical records of all patients, and tested statistical significance with the Fisher's test. Results: Reoperation was performed in 20 cases, but the cases include hematoma with bleeding focus and arterial anastomosis site rupture due to abrupt arm abduction. We performed reoperation in 15 cases of suspicious vascular compromise. Flap compromise was noticed mostly within 24 hours, but not longer than 72 hours. Venous compromise was dominant by 11 cases (73.3%). There was difference in the timing of flap compromise between immediate and delayed reconstruction. All the cases of delayed reconstruction did not show signs of vascular compromise after 12 hours postoperatively. On the other hand, cases of vascular compromise were observed until 72 hours postoperatively in cases of immediate reconstruction. Conclusion: Delayed reconstruction showed vascular compromise within 12 hours postoperatively, while immediate reconstruction showed compromised until the 3rd postoperative day. If more aggressive monitoring is maintained during this period, we believe salvage of flaps may be increased with more efficiency.

• Archives of Plastic Surgery
• /
• v.46 no.2
• /
• pp.140-146
• /
• 2019

Background Thoracodorsal vessels (TDVs) and internal mammary vessels (IMVs) have both been widely employed as recipient vessels for use in free muscle-sparing transverse rectus abdominis myocutaneous (MS-TRAM) flaps. However, whether TDVs or IMVs are preferable as recipient vessels for autologous breast reconstruction with a free MS-TRAM flap remains controversial. The purpose of this study was to compare the clinical outcomes when TDVs were used as recipient vessels to those obtained when IMVs were used as recipient vessels for autologous breast reconstruction with a free MS-TRAM flap. Methods A retrospective matched-cohort study was performed. We retrospectively reviewed data collected from patients who underwent a free MS-TRAM flap for autologous breast reconstructions after mastectomy between March 2003 and June 2013. After a one-to-one matching using age, 100 autologous breast reconstructions were selected in this study. Of the 100 breast reconstructions, 50 flaps were anastomosed to TDVs and 50 to IMVs. Patient demographics and clinical outcomes including operation time, length of hospital stay, postoperative complications, and aesthetic score were compared between the two groups. Results No statistically significant differences were found between the two groups in patient demographics and clinical outcomes, including the complication rates and aesthetic scores. There were no major complications such as total or partial flap loss in either group. Conclusions The results of our study demonstrate that both TDVs and IMVs were safe and efficient as recipient vessels in terms of the complication rates and aesthetic outcomes.

• Archives of Plastic Surgery
• /
• v.49 no.3
• /
• pp.324-331
• /
• 2022

Prior abdominal liposuction can be viewed as a relative or absolute contraindication to abdominally based autologous breast reconstruction given concerns for damaged perforators and scarring complicating intraoperative dissection. This systematic review aims to explore the outcomes of abdominally based breast reconstruction in patients with a history of abdominal liposuction. A Preferred Reporting Items for Systematic Reviews and Meta-Analyses-guided literature search was conducted using PubMed, Scopus, and Web of Science from the earliest available date through June 2020. Deep inferior epigastric perforator, muscle-sparing transverse rectus abdominis musculocutaneous (TRAM), superficial inferior epigastric artery, and pedicled TRAM flaps were included for evaluation. Complications included total or partial flap loss, fat necrosis, seroma, delayed wound healing, and donor site complications. After inclusion criteria were applied, 336 non-duplicate articles were screened, yielding 11 for final review, representing 55 flaps in 43 patients. There was no instance of total flap loss, eight (14.5%) flaps developed partial loss or fat necrosis, three (5.4%) flaps had delayed wound healing, and two (4.6%) patients had donor site complications. Most authors (8/11) utilized some type of preoperative imaging. Doppler ultrasonography was the most used modality, and these patients had the lowest rate of partial flap loss or flap fat necrosis (8%), followed by those without any preoperative imaging (10%). In conclusion, this review supports that patients undergoing abdominally based autologous breast reconstruction with a history of abdominal liposuction are not at an increased risk of flap or donor site complications. Although preoperative imaging was common, it did not reliably decrease complications. Further prospective studies are needed to address the role of imaging in improving outcomes.

• KIPS Transactions on Software and Data Engineering
• /
• v.10 no.12
• /
• pp.561-568
• /
• 2021

In recent years, autonomous driving technologies have become a high-value-added technology that attracts attention in the fields of science and industry. For smooth Self-driving, it is necessary to accurately detect an object and estimate its movement speed in real time. CNN-based deep learning algorithms and conventional dense optical flows have a large consumption time, making it difficult to detect objects and estimate its movement speed in real time. In this paper, using a single camera image, fast object detection was performed using the YOLOv5 algorithm, a deep learning algorithm, and fast estimation of the speed of the object was performed by using a local dense optical flow modified from the existing dense optical flow based on the detected object. Based on this algorithm, we present a system that can predict the collision time and probability, and through this system, we intend to contribute to prevent tram accidents.

• The Research Journal of the Costume Culture
• /
• v.28 no.4
• /
• pp.409-419
• /
• 2020

Building on Technology Readiness and Acceptance Model(TRAM), the study aimed to examine how technology readiness affects consumers' perceptions of ease of use, usefulness, and risk, which in turn predict their intention to use retail service robots. Specifically, the study proposed that technology readiness motivators (optimism and innovativeness) would influence perceived ease of use and usefulness, while technology readiness inhibitors (discomfort and insecurity) would affect perceived risk. The study further examined if the perception factors (ease of use, usefulness, and risk) contribute to intention to use retail service robots. A survey method was used with data collected from Korean consumers. The final sample size was 418. The data was analyzed using structural equation modeling. Findings of the study revealed that technology readiness motivators positively affected perceived ease of use and usefulness while innovativeness had no impact on usefulness. All the inhibitors increased perceived risk. Lastly, as hypothesized, perceptions of ease of use, usefulness, and risk predicted intention to use retail service robots. This study extended the retail technology literature by applying and validating TRAM to the context of consumer acceptance of retail service robots. The study further helped marketers and retailers by highlighting the importance of technology readiness in improving consumer perceptions and responses towards retail service robots.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2009.06a
• /
• pp.477-477
• /
• 2009

Bimodal Tram developed by KRRI is driven by a series Hybrid propulsion system which has both the CNG engine, generator and LPB(Lithium Polymer Battery) pack. It has three driving modes; Hybrid mode, Engine mode and Battery mode. Even in case of Battery mode, LPB pack to get enough power to drive the vehicle only by itself onsists of 168 LPB cells(80Ah per lcell), 650V. It is important thing to manage LPB pack in a right way, which will extend the lifetime of LPB cells and operate in the hybrid mode effectively. This paper has shown the development of battery management system(12 BMS, 1 BMS per 14cells) to manage LPB pack which is connected with CAN(Controller Area Network) each other and measure the voltage, current, temperature and also control the cooling fan inside of LPB pack. Using the measured data, BMS can show the SOC(State of Charge), SOH(State of Health) and other status of LPB pack including of the cell balancing.

• Advanced Composite Materials
• /
• v.18 no.1
• /
• pp.1-20
• /
• 2009

This paper describes the results of experiments and numerical simulation studies on the impact and indentation damage created by low-velocity impact subjected onto honeycomb sandwich panels for application to the BIMODAL tram. The test panels were subjected to low-velocity impact loading using an instrumented testing machine at six energy levels. Contact force histories as a function of time were evaluated and compared. The extent of the damage and depth of the permanent indentation was measured quantitatively using a 3-dimensional scanner. An explicit finite element analysis based on LS-DYNA3D was focused on the introduction of a material damage model and numerical simulation of low-velocity impact responses on honeycomb sandwich panels. Extensive material testing was conducted to determine the input parameters for the metallic and composite face-sheet materials and the effective equivalent damage model for the orthotropic honeycomb core material. Good agreement was obtained between numerical and experimental results; in particular, the numerical simulation was able to predict impact damage area and the depth of indentation of honeycomb sandwich composite panels created by the impact loading.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.64 no.4
• /
• pp.231-235
• /
• 2015

Bimodal Tram developed by KRRI is driven by a series Hybrid propulsion system which has both the CNG engine, generator and LPB(Lithium Polymer Battery) pack. It has three driving modes; Hybrid mode, Engine mode and Battery mode. Even in case of Battery mode, LPB pack to get enough power to drive the vehicle only by itself onsists of 168 LPB cells(80Ah per lcell), 650V. It is important thing to manage LPB pack in a right way, which will extend the lifetime of LPB cells and operate in the hybrid mode effectively. This paper has shown the development of battery management system(12 BMS, 1 BMS per 14cells) to manage LPB pack which is connected with CAN(Controller Area Network) each other and measure the voltage, current, temperature and also control the cooling fan inside of LPB pack. Using the measured data, BMS can show the SOC(State of Charge), SOH(State of Health) and other status of LPB pack including of the cell balancing.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.23 no.5
• /
• pp.524-536
• /
• 2015

The paper aims to design and verify tearing tube type energy absorption device applied in tram to ensure safety in case of collision accident. Energy capacity of tearing tube is determinated based on EN15227 and Standard Collision Scenarios Criterion in Detail in Republic of Korea. Tearing tube is designed based on theoretical model suggested by X.Huang et al. and assumption by T.Y. Reddy et al. Real scale collision tests are conducted to analyze the energy absorption characteristics and deformation mode. Bending of curl tips is absorbed collision energy when curl tips and tube body are contacted to each other from the tests and we suggest and include the formula on bending of curl tips in theoretical model.

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.99-108
• /
• 2007

The bi-modal tram guided by the magnetic guidance system has two car-bodies and three axles. Each axle of the vehicle has an independent suspension to lower the floor of the car and improve ride quality. The turning radius of the vehicle may increase as a consequence of the long wheel base. Therefore, the vehicle is equipped with the All-Wheel-Steering(AWS) system for safe driving on a curved road. Front and rear axles should be steered in opposite directions, which means a negative mode, to minimize the turning radius. On the other hand, they also should be steered in the same direction, which means a positive mode, for the stopping mode. Moreover, only the front axle is steered for stability of the vehicle upon high-speed driving. In summary, steering angles and directions of the each axle should be changed according to the driving environment and steering mode. This paper proposes an appropriate AWS control algorithm for stable driving of the bi-modal tram. Furthermore, a multi-body model of the vehicle is simulated to verify the suitability of the algorithm. This model can also analyze the different dynamic characteristics between 2WS and AWS.