• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.1
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• pp.38-44
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• 2002

In manufacturing die and mold, polishing: is important as it takes as much as 50% of the production cost. In this research, an attachable type polishing device to a WC machining center was developed. experiments were done with a special1y designed rotation type polishing device. Also an ultra-sonic (vibration type) waving device was introduced to acquire finer surface finishes. From the constructed data base based on the experimental results, it is shown that optimal polishing conditions are generated by the combined use of the rotation type tool and the vibration type tool.

• Journal of Electrical Engineering and Technology
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• v.13 no.1
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• pp.152-159
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• 2018

In this paper, a novel topology of two-level voltage-type inverter is proposed. The proposed inverter has three bridge arms while each bridge is made up of two thyristors, one IGBT and four diodes. Thyristors complete the phase positioning of the inverter, IGBT completes the modulation of different modulation modes such as SPWM, SVPWM, and SHPWM, and the diodes complete the commutation of the bridge arms. Compared to the traditional voltage-type inverter with six IGBTs, the proposed voltage-type inverter using three IGBTs can achieve the same function with highly reduced cost. The principle of the proposed two-level inverter is explained in detail. The simulation and experiment results demonstrate the performance and effectiveness of the proposed inverter-type inverter.

• Journal of Chest Surgery
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• v.16 no.3
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• pp.337-341
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• 1983

The experience with operative treatment for total correction of Tetralogy of Fallot at the department of Thoracic and Cardiovascular Surgery, Korea University Hospital from January, 1977, through April, 1983 was reviewed. Of the 29 patients reviewed, male to female occurrence ratio was 22:7 Type of V.S.D. was type II in 26 cases[90%] and total conus defect in 3 cases[10%]. Average size of V.S.D. was 19 mm. Type of Right ventricular outflow tract stenosis was highest frequency with pulmonary valvular and infundibular stenosis combined type in 21 cases[72%], and there were 8 deaths In this group. Type of R.V.O.T. reconstruction contains 2 cases of infundibulectomy only, 1 case of infundibulectomy with valvular commissurotomy, 2 cases of pericardial patch, 23 Cases of pericardial patch with Teflon or Dacron felt reinforced and 1 case of pulmonary valved conduit reconstruction. Operative mortality was higher in outflow patch through pulmonary valve ring. Overall mortality was 31%. Major causes of death and postoperative complications were low output syndrome, complete A-V block acute renal failure, ventricular fibrillation, bleeding brain abscess, and sudden cardiac arrest.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.6 no.1
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• pp.39-42
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• 1995

Surgical treatment options of symptomatic unilateral vocal fold paralysis are Teflon injection, type Ⅰ thyroplasty, and arytenoid adduction. Arytenoid adduction is preferable to type Ⅰ thyroplasty for correcting the level different that may be present between two vocal folds and the large glottal chink However there is no known therapeutic modality effective to correct the large posterior glottal chink of the vocal fold with relatively normal mobility. Recently we have experienced a case of severe large posterior glottal chink of the vocal 1314s with relatively normal mobility after thyroid lobectomy, successfully treated with type Ⅰ thyroplasty combined with arytenoid adduction.

• Proceedings of the KIEE Conference
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• summer
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• pp.384-387
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• 2004

The direction and the type of a fault on a transmission line need to be identified rapidly and correctly, The work described in this paper addresses the problem encountered by a conventional algorithm in a fault type classification in double circuit line, this arises due to a mutual coupling and CT saturation under the fault condition. We present an approach to identify fault type with novel neural network on double circuit transmission line. The neural network based on combined unsupervised training method provides the ability classify the fault type by different patterns of the associated voltages and currents.

• International Journal of High-Rise Buildings
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• v.10 no.3
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• pp.211-218
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• 2021

A new type of earthquake resilient reinforced concrete (RC) shear wall structure, installed with replaceable coupling beams and replaceable corner components at the bottom of wall piers, is proposed in this study. At first, the mechanical behavior of replaceable components, such as combined dampers and replaceable corner component, is studied by cyclic loading tests on them. Then, cycling loading tests are conducted on one conventional coupled shear wall and one new type of coupled shear wall with replaceable components. The test results indicate that the damage of the new type of coupled shear wall concentrates on replaceable components and the left parts are well protected. Finally, a case study is introduced. The responses of one conventional frame-tube structure and one new type of structure installed with replaceable components under the wind and the earthquake are compared, which verify that the performance of new type of structure is much better than the conventional structure.

• Journal of Chest Surgery
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• v.57 no.1
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• pp.99-102
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• 2024

This article presents a straightforward hybrid arch technique for treating residual type B aortic dissecting aneurysms following type A repair (replacement of the ascending aorta) that employs a frozen elephant trunk (FET) straight vascular prosthesis. The debranch-first method involves only cutting and sewing the previous ascending graft, inserting the FET from zone 0, and debranching the arch vessels using a trifurcated graft. This technique is less invasive as it eliminates the need to manipulate the dissected distal arch aneurysm. We successfully applied this technique to 3 patients, with no instances of in-hospital death, stroke, or paraplegia. The debranch-first technique, combined with zone-0 FET insertion, simplifies the redo repair of residual type B aortic dissection.

• Journal of Biomedical Engineering Research
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• v.36 no.6
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• pp.276-282
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• 2015

Recently, during the multi-level fusion with pedicle screws, interspinous spacer are sometimes substituted for the most superior level of the fusion in an attempt to reduce the number of fusion level and likelihood of degeneration process at the adjacent level. In this study, a finite element (FE) study was performed to assess biomechanical efficacies of the interspinous spacer combined with posterior lumbar fusion with a previously-validated 3-dimensional FE model of the intact lumbar spine (L1-S1). The post-operative models were made by modifying the intact model to simulate the implantation of interspinous spacer and pedicle screws at the L3-4 and L4-5. Four different configurations of the post-op model were considered: (1) a normal spinal model; (2) Type 1, one-level fusion using posterior pedicle screws at the L4-5; (3) Type 2, two-level (L3-5) fusion; (4) Type 3, Type 1 plus Coflex$^{TM}$ at the L3-4. hybrid protocol (intact: 10 Nm) with a compressive follower load of 400N were used to flex, extend, axially rotate and laterally bend the FE model. As compared to the intact model, Type 2 showed the greatest increase in Range of motion (ROM) at the adjacent level (L2-3), followed Type 3, and Type 1 depending on the loading type. At L3-4, ROM of Type 2 was reduced by 34~56% regardless of loading mode, as compared to decrease of 55% in Type 3 only in extension. In case of normal bone strength model (Type 3_Normal), PVMS at the process and the pedicle remained less than 20% of their yield strengths regardless of loading, except in extension (about 35%). However, for the osteoporotic model (Type 3_Osteoporotic), it reached up to 56% in extension indicating increased susceptibility to fracture. This study suggested that substitution of the superior level fusion with the interspinous spacer in multi-level fusion may be able to offer similar biomechanical outcome and stability while reducing likelihood of adjacent level degeneration.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.6
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• pp.511-519
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• 2001

Nimopidine, one of dihydropyridine derivatives, has been widely used to pharmacologically identify L-type Ca currents. In this study, it was tested if nimodipine is a selective blocker for L-type Ca currents in sensory neurons and heterologous system. In mouse dorsal root ganglion neurons (DRG), low concentrations of nimodipine $(<10\;{\mu}M),$ mainly targeting L-type Ca currents, blocked high-voltage-activated calcium channel currents by ${\sim}38%.$ Interestingly, high concentrations of nimodipine $(>10\;{\mu}M)$ further reduced the 'residual' currents in DRG neurons from ${\alpha}_{1E}$ knock-out mice, after blocking L-, N- and P/Q-type Ca currents with $10\;{\mu}M$ nimodipine, $1\;{\mu}M\;{\omega}-conotoxin$ GVIA and 200 nM ${\omega-agatoxin$ IVA, indicating inhibitory effects of nimodipine on R-type Ca currents. Nimodipine $(>10\;{\mu}M)$ also produced the inhibition of both low-voltage-activated calcium channel currents in DRG neurons and ${\alpha}_{1B}\;and\;{\alpha}_{1E}$ subunit based Ca channel currents in heterologous system. These results suggest that higher nimodipine $(>10\;{\mu}M)$ is not necessarily selective for L-type Ca currents. While care should be taken in using nimodipine for pharmacologically defining L-type Ca currents from native macroscopic Ca currents, nimodipine $(>10\;{\mu}M)$ could be a useful pharmacological tool for characterizing R-type Ca currents when combined with toxins blocking other types of Ca channels.

• Structural Engineering and Mechanics
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• v.87 no.3
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• pp.231-242
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• 2023

A novel combinatorial type-2 adaptive neuro-fuzzy inference system (T2-ANFIS) and robust proportional integral derivative (PID) control framework for intelligent vibration mitigation of uncertain structural system is introduced. The fuzzy logic controllers (FLCs), are designed independently of the mathematical model of the system. The type-1 FLCs, have a limited ability to reduce the effect of uncertainty, due to their fuzzy sets with a crisp degree of membership. In real applications, the consequent part of the fuzzy rules is uncertain. The type-2 FLCs, are robust to the fuzzy rules and the process parameters due to the fuzzy degree of membership functions and footprint of uncertainty (FOU). The adaptivity of the proposed method is provided with the optimum tuning of the parameters using the neural network training algorithms. In our approach, the PID control force is obtained using the generalized type-2 neuro-fuzzy in such a way that the stability and robustness of the controller are guaranteed. The robust performance and stability of the presented framework are demonstrated in a numerical study for an eleven-story seismically-excited building structure combined with an active tuned mass damper (ATMD). The results indicate that the introduced type-2 neuro-fuzzy PID control scheme is effective to attenuate plant states in the presence of the structured and unstructured uncertainties, compared to the conventional, type-1 FLC, type-2 FLC, and type-1 neuro-fuzzy PID controllers.