• Journal of Power Electronics
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• 제16권5호
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• pp.1791-1801
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• 2016

This paper considers a carrier based signal injection method for use in the three shunt sensing inverter (TSSI) for sensorless motor control. It also analyzes the loss according to the injection axis of the voltage signal. To remove both the phase current and rotor position sensors, a sensorless method and a phase current reconstruction method can be simultaneously considered. However, an interaction between the two methods can be incurred when both methods inject voltage signals simultaneously. In this paper, a signal injection based sensorless method with the 120° OFF Discontinuous PWM (DPWM) is implemented in a TSSI to avoid this interaction problem. Since one leg does not have a switching event for one sampling period in the 120° OFF DPWM, the switching loss is altered according to the injection axis. The switching loss in the d-axis injection case can be up to 32% larger than that in the q-axis injection case. Other losses according to the injection axis are also analyzed.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2017년도 전력전자학술대회
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• pp.208-209
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• 2017

When controlling a three-phase inverter that drives AC motor, it is important to know the value of the current. In this case, shunt sensing methods are known as low cost and useful performance. However, for certain swithcing condition, immeasurable areas exist and it is necessary to reconstruct the current in the area. This paper proposes a reconstruction method using voltage injection in synchronous coordinates system at the area, and verify the validity of the method through simulation.

• Archives of Plastic Surgery
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• 제43권5호
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• pp.424-429
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• 2016

Background The objective of this paper was to describe a novel technique for improving the maintenance of nipple projection in primary nipple reconstruction by using acellular dermal matrix as a strut in one of three different configurations, according to the method of prior breast reconstruction. The struts were designed to best fill the different types of dead spaces in nipple reconstruction depending on the breast reconstruction method. Methods A total of 50 primary nipple reconstructions were performed between May 2012 and May 2015. The prior breast reconstruction methods were latissimus dorsi (LD) flap (28 cases), transverse rectus abdominis myocutaneous (TRAM) flap (10 cases), or tissue expander/implant (12 cases). The nipple reconstruction technique involved the use of local flaps, including the C-V flap or star flap. A $1{\times}2-cm$ acellular dermal matrix was placed into the core with O-, I-, and L-shaped struts for prior LD, TRAM, and expander/implant methods, respectively. The projection of the reconstructed nipple was measured at the time of surgery and at 3, 6, and 9 months postoperatively. Results The nine-month average maintenance of nipple projection was $73.0%{\pm}9.67%$ for the LD flap group using an O-strut, $72.0%{\pm}11.53%$ for the TRAM flap group using an I-strut, and $69.0%{\pm}10.82%$ for the tissue expander/implant group using an L-strut. There were no cases of infection, wound dehiscence, or flap necrosis. Conclusions The application of an acellular dermal matrix with a different kind of strut for each of 3 breast reconstruction methods is an effective addition to current techniques for improving the maintenance of long-term projection in primary nipple reconstruction.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1461-1466
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• 2008

In the case of Posterior Cruciate Ligament (PCL), the most frequent mechanism is the dashboard injury, which is directly pressurized to the anterior of the proximal tibia in the state of the knee hyperflexion. The PCL associated ligament damage happens when the posterior injury, the varus, the valgus, the hyperextension and the severe vagus torque are out of the critical value of PCL. After the successful operation cases of Anterior Cruciate Ligament (ACL) reconstruction using the allograft were informed from 1986, a number of results kept over the maximum 10 years were reported. Unfortunately, PCL reconstruction are crowded the surgery techniques such as the graft, the tibia fixing method, the fixation device, the location of the femoral tunnel, the number of the graft bundles and PCL reconstruction to access to the stability of the normal joint is being developed. Therefore, this study is the basic research of these above facts. The current transtibial tunnel surgery using the cadaveric Achilles tendon grafts is chosen for the various PCL reconstruction. The initial extension of the Achilles tendon by the fixing device and its location under the cyclic loading, were observed.

• 대한두개안면성형외과학회지
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• 제18권3호
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• pp.149-154
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• 2017

Computer-aided surgery (CAS) started being used for head and neck reconstruction in the late 2000s. Its use represented a paradigm shift, changing the concept of head and neck reconstruction as well as mandible reconstruction. Reconstruction using CAS proceeds through 4 phases: planning, modeling, surgery, and evaluation. Thus, it can overcome a number of trial-and-error issues which may occur in the operative field and reduce surgical time. However, if it is used for oncologic surgery, it is difficult to evaluate tumor margins during tumor surgery, thereby restricting pre-surgical planning. Therefore, it is dangerous to predetermine the resection margins during the presurgical phase and the variability of the resection margins must be taken into consideration. However, it allows for the preparation of a prebending plate and planning of an osteotomy site before an operation, which are of great help. If the current problems are resolved, its applications can be greatly extended.

• Current Optics and Photonics
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• 제6권3호
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• pp.244-251
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• 2022

We introduce a spectral reconstruction method to enhance the spectral resolution in a static modulated Fourier-transform spectrometer. The optical-path difference and the interferogram in the focal plane, as well as the relationship of the interferogram and the spectrum, are discussed. Additionally, for better spectral reconstruction, applications of phase-error correction and apodization are considered. As a result, the transfer function of the spectrometer is calculated, and then the spectrum is reconstructed based on the relationship between the transfer function and the interferogram. The spectrometer comprises a modified Sagnac interferometer. The spectral reconstruction is conducted with a source with central wave number of 6,451 cm^-1 and spectral width of 337 cm^-1. In a conventional Fourier-transform method the best spectral resolution is 27 cm^-1, but by means of the spectral reconstruction method the spectral resolution improved to 8.7 cm^-1, without changing the interferometric structure. Compared to a conventional Fourier-transform method, the spectral width in the reconstructed spectrum is narrower by 20 cm^-1, and closer to the reference spectrum. The proposed method allows high performance for static modulated Fourier-transform spectrometers.

• 한국주거학회논문집
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• 제15권3호
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• pp.109-116
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• 2004

The purpose of this study is to improve the residential environment of the deteriorated apartment in Gyeongju. We survey the characteristics of each of the seven buildings in the subject housing, the renovations of each unit and the overall environment, and the residents' perceptions. The findings show that the residents of the deteriorated apartment in Gyeongju are generally satisfied with the current residential environment and that they prefer the reconstruction to improve their environment. The results also include that the residents feel burdened with the reconstruction because it is difficult to receive the approval from the local government and it is highly costly from the view points of the residents. It is recommendable to establish the logical judging criteria on the reconstruction. reuse, or renovation of the deteriorated apartment in a small local city such as Gyeongju and to offer the objective and specific programs on the basis of the established criteria for the improvement of the residential environment in the future.

• Archives of Plastic Surgery
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• 제33권1호
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• pp.53-60
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• 2006

The current authors performed two-stage ear reconstruction of microtia using autogenous costal cartilage combined with canaloplasty of the acoustic meatus in a team approach. In the first stage, lobule transposition, fabrication of the cartilage framework, and implantation of the framework were peformed. In the second stage, elevation of the auricle, cartilage graft for posterior auricular sulcus, coverage with the mastoid fascia flap and skin graft, and concha excavation were performed. The canaloplasty was combined simultaneously in patients with radiologic and audiometric evidence of cochlear function in the second stage. A total of 36 consecutive patients with congenital microtia were treated from 1998 to 2003. Among them, 27 patients(male: 18, female: 9) ranging from 7 to 43 years old were combined with canaloplasty. The follow-up period was one year to 5 years. Thirteen patients exhibited improved hearing over 30 dB PTA(pure tone average), 9 patients below 30 dB, and 5 patients with no improvement. Complications related to the canaloplasty were chronic drainages of the auditory meatus and meatal stenosis. Lobule type deformity combined with the canaloplasty showed higher complications than concha type. Therefore, in the lobule type, meticulous manipulation is necessary to reduce complications after the canaloplasty.

• Journal of Electrical Engineering and Technology
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• 제13권2호
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• pp.781-789
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• 2018

This paper proposes a new approach utilizing empirical mode decomposition (EMD) reconstruction to process vibration signals of a transformer under DC bias caused by high voltage direction transmission (HVDC), which is the potential cause of additional vibration and noise from transformer. Firstly, the Calculation Method is presented and a 3D model of transformer is simulated to analyze transformer deformation characteristic and the result indicate the main vibration is produced along axial direction of three core limbs. Vibration test system has been built and test points on the core and shell of transformer have been measured. Then, the signal reconstruction method for transformer vibration based on EMD is proposed. Through the EMD decomposition, the corrupted noise can be selectively reconstructed by the certain frequency IMFs and better vibration signals of transformer have been obtained. After EMD reconstruction, the vibrations are compared between transformer in normal work and with DC bias. When DC bias occurs, odd harmonics, vibration of core and shell, behave as a nonlinear increase and the even harmonics keep unchanged with DC current. Experiment results are provided to collaborate our theoretical analysis and to illustrate the effectiveness of the proposed EMD method.

• 대한족부족관절학회지
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• 제26권2호
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• pp.103-106
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• 2022

Peroneal tendon disorders are one of many causes of chronic lateral ankle pain. They are related to chronic conditions and anatomical factors and can cause persistent pain and functional impairment if neglected. Peroneal tendon tears are frequently misdiagnosed due to the absence of clear symptoms. For subacute or chronic peroneal tendon ruptures, tendons often became irreparable, and hence various surgical options have been introduced to address this issue. Current surgical treatment options include debridement and tubularization, tenodesis, tendon transfer, and reconstruction with a graft. There have been a few reports on the use of reconstruction techniques with an allograft. In this report, we present a rare case of a peroneal tendon reconstruction technique using an allograft in a young male with simultaneous irreparable peroneus longus and a complete rupture of the brevis tendon. The management plan, prognostic outlook, and a subsequent review of the relevant literature are also presented.