• Archives of Plastic Surgery
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• v.51 no.1
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• pp.110-117
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• 2024

Percutaneous first annular pulley (A1 pulley) release, which has been increasingly used to treat trigger fingers, has been widely established as a safe and simple procedure. Multiple studies have reported positive results of percutaneous A1 pulley release. In this study, however, we report cases of patients who developed complications after undergoing percutaneous A1 pulley release at local clinics. A total of six patients visited our hospital for infectious complications after percutaneous A1 pulley release. Various sequelae such as damage to normal structures, insufficient procedure, and tissue necrosis were observed during the exploration. A retrospective study was conducted to identify the cause and trend of the observed complications by instruments (HAKI knife or needle). In the HAKI knife group, there was a tendency for damage to normal structures, while in the needle group, an insufficient release or serious soft tissue necrosis was observed. Based on these cases, our findings confirm the existence and characteristics of infectious complications following the percutaneous A1 pulley release. We further identify that the type of instrument used predicts the nature of complications. Thus, reliable and skilled performance of the procedure by experts is essential for safe treatment.

• Journal of Korean Foot and Ankle Society
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• v.19 no.4
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• pp.176-180
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• 2015

Purpose: The aim of the current study is to report on the clinical and radiographic results after calcaneo-stop procedure in Korean children with symptomatic flexible flatfoot. Materials and Methods: Twenty-two children suffering pain along the medial aspect of midfoot with flexible flatfoot whose symptoms did not improve with conservative measures and therefore underwent calcaneo-stop procedure were identified retrospectively. Clinically, American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale and visual analogue scale (VAS) were evaluated. Radiographically, standing anteroposterior and lateral radiographs of the foot and Saltzman's alignment views were taken and talonavicular coverage angle, lateral talo-first metatarsal angle, and hindfoot alignment angles were measured and analyzed. Results: Clinically, AOFAS ankle-hindfoot scale improved from $70.3{\pm}5.6$ to $97.3{\pm}2.5$ and VAS improved from $6.4{\pm}1.6$ to $0.2{\pm}0.4$. Radiographically, talonavicular coverage angle improved from $28.3^{\circ}{\pm}12.3^{\circ}$ to $10.9^{\circ}{\pm}8.1^{\circ}$, lateral talo-first metatarsal angle improved from $-19.3^{\circ}{\pm}9.0^{\circ}$ to $-2.4^{\circ}{\pm}8.1^{\circ}$, and hindfoot alignment angle improved from valgus $11.9^{\circ}{\pm}10.0^{\circ}$ to $3.5^{\circ}{\pm}4.3^{\circ}$ at minimum 2-year follow-up. No complications occurred postoperatively. Conclusion: Calcaneo-stop procedure is a simple and very effective procedure for management of pediatric symptomatic flexible flatfoot that does not respond to conservative treatment.

• Proceedings of the Korean Geotechical Society Conference
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• 1994.09a
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• pp.259-264
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• 1994

The 1986 AASHTO Guide for the Design of Pavement Structures introduced the resilient modulus as a definitive material property to characterize roadbed soil. Although the incorporation of resilient modulus represents a significant acvance in pavement design practice, the test procedure for resilient modulus is complicated and time-consuming. Therefore, it is necessary to develop data base of resilient modulus for the soils frequently encountered; and to develop the reliable correlations between resilient properties and parameters from simple routine tests, In this study, resilient modulus tests were performed on five cohesive soils sampled from in-service subgrades. The stress at 1 percent axial strain in unconfined compression test(su1.0%) was found as a good indicator of the resilient modulus, and unique relationship between Mg and Su1.0% was obtained. A simple chart to estimate the resilient modulus at different levels of confining stress and deviator stress was also developed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.299-304
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• 2009

A hybrid electromagnetic actuator with an air spring is designed so as to achieve the desired isolation reduce the vibration efficiency on the floor vibration. The performance specification of the hybrid electromagnetic actuator is determined based on the vibration criterion for vibration-sensitive equipment. In basic design stage of the electromagnetic actuator, the simple reluctance method is adapted to analyze magnetic circuits. The result is verified by finite element analysis using ANSYS Emag. Finally, some design parameters are optimized under several constraint conditions. Through this study, the design procedure for a specific electromagnetic actuator is set up using a simple reluctance method.

• Journal of Electrical Engineering and Technology
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• v.4 no.3
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• pp.301-309
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• 2009

A simple and efficient Lambda logic (${\lambda}-logic$) based algorithm is proposed for the solution of the generator constrained economic dispatch problem when the generating units having prohibited zones. The proposed method solves the economic dispatch (ED) problem that takes into account ramprate limits, transmission losses and prohibited operating zones in the power system operation. The proposed method uses a simple heuristic rule based on average power of prohibited operating zones which produces the feasibility of solution for the restricted operating units. The effectiveness of the algorithm is tested on five different test systems and the performance compared with other relevant methods reported in the literature. In all the cases, the proposed algorithm performs better than the previous existing algorithms with a less computational burden.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.250-252
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• 1996

In this paper, the principle of operation. the part characteristic, characteristic of component movement, analysis are carried out for camcoder iris assembly which is one of the important element component in Video large projection TV instrument, and some Know-how for development of element component is also included. The magnetic field circuit for the small and simple structure with low power consumption is introduced and new materials of yoke for small motor system is suggested. Especially, the relation with remained magnetic field and operation duration time is analyzed by experimental results. Some problems of nonlinear torque characteristics include to obtain the simple and low cost structure in domestic production of element component is analyzed. Furthermore, development procedure is suggested for iris assembly and some methods to reduce the burr with some check points for small precise accessories are explained.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.2
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• pp.112-118
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• 2000

This paper deals with the application of sensitivity method to the parameter estimation for the dynamic analysis of gener-al mechanical system. In this procedure we take the derivatives of the given system with respect to a certain parameter and use this information to implement the steepest descent method. This paper will give two examples of this technique applied to simple vehicle models. This paper will give two examples of this technique applied to simple vehicle models. Simulation results show excellent convergence and accuracy of parameter estimates.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.6 s.99
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• pp.706-711
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• 2005

Torsional oscillations of a system incorporating a Hooke's joint are investigated by studying a simple similar nonlinear 2-degree-of-freedom model, which has linear and quadratic nonlinear parametric excitations. The simple system is identified to have the possibilities of primary, sub harmonic and combination resonances. The case of simultaneous primary and combination resonances is selected for perturbation analysis to have the reduced amplitude-equations of motion. The same procedure is applied to the system incorporating a Hooke's joint.

• Structural Engineering and Mechanics
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• v.68 no.1
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• pp.121-130
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• 2018

This study deals with optimum geometry design of laterally loaded piles in a Winkler's medium through the Fully Stressed Design (FSD) method. A numerical algorithm distributing the mass by means of the FSD method and updating the moment by finite elements is implemented. The FSD method is implemented here using a simple procedure to optimise the beam length using an approach based on the calculus of variations. For this aim two conditions are imposed, one transversality condition at the bottom end, and a one sided constraint for moment and mass distribution in the lower part of the beam. With this approach we derive a simple condition to optimise the beam length. Some examples referred to different fields are reported. In particular, the case of laterally loaded piles in Geotechnics is faced.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.8
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• pp.760-766
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• 2008

This paper proposes an efficient location technique to find an indoor location under the IEEE 802.11 wireless local area networks. The proposed method is based on the range measurements obtained from a simple radio frequency propagation model. Thus, unlike the radio frequency fingerprint correlation method, it does not suffer from the computational burden during the real-time location service period and can quickly reply the location requests of many users at the same time. To increase the location accuracy in spite of the frequent non-line-of-sight error occurrences, the proposed method calibrates the distortion of the non-line-of-sight error by a simple measurement surveying procedure that does not require the surveyor's manual interaction. Experimental results show the capability of the proposed method.