• Journal of Korean Society for Quality Management
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• v.18 no.2
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• pp.9-17
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• 1990

This paper deals with a FOQ( ; fixed-order quantity) model for spare-part inventory control. In a spare-part inventory problem, stock depletion arises not from external market demand but from internal demand resulting from failures of parts in use. The problem differs from the classical inventory problem in that the demand for a failed part never arises more during stockout period, since the unit remains inoperative when stockout occurs until the failed part is replaced by new one. In the problem under consideration, n identical units are operating simultaneously and failed one is replaced immediately by new one if on-hand spares remain. In order to replenish spares, an order with quantity Q is placed whenever the number of on-hand spares falls to levels. The average annual cost of operating the spare-part inventory system is derived under the assumption that both lifetime of a part and replenishment lead-time distributions are exponential.

• Journal of Korean Foot and Ankle Society
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• v.9 no.2
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• pp.197-200
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• 2005

We performed lateral ankle ligament reconstructions using Achilles allograft on patients who had failed previous Brostrom repair. The bone plug is fixed with an interference screw into the calcaneus, the tendon graft is passed through a fibular tunnel, and then anchored into the talus with the biotenodesis screw. The graft is strong enough to maintain joint stability until graft incorporation and remodeling occurs. In patients with chronic failed lateral ankle instability requiring graft for ligament reconstruction, this technique allows anatomic reconstruction without the need to sacrifice autogenous peroneal tendons.

• Korean Journal of Acupuncture
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• v.28 no.3
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• pp.233-244
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• 2011

Objectives : To evaluate the effectiveness of direct moxibustion in patients with failed back surgery syndrome (FBSS). Methods : 5 patients (3 females and 2 males) with FBSS underwent direct moxibustion on ouch points (阿是穴) for 10 to 15 weeks (once a week). The effectiveness of the treatment was evaluated with NRS (numerical rating scale), ODI (Oswestry disability index), BDI (Beck depression inventory) score, SF-36 (short form 36 health survey) score and PSQI (Pittsburgh sleep quality index) before and after the treatment. Results : Within observation period, average value changed from 10.0 to 4.2 in NRS of pain, from 37.0 to 20.6 in ODI, from 20.6 to 12.0 in BDI score, 42.2 to 62.6 in SF-36 score, and from 8.6 to 5.2 in PSQI. Conclusions : Direct moxibustion on FBSS patients showed more or equivalent effectiveness when compared to conventional FBSS treatment modalities.

• Journal of Chest Surgery
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• v.44 no.6
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• pp.452-454
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• 2011

The most common surgical procedure used to manage tracheoesophageal fistula is the primary anastomosis of the esophagus. However, in the case of failed anastomosis, replacing the esophagus with another organ is necessary. We performed two procedures of colon interposition after failure of tracheoesophageal fistula repair. In those cases, stomach replacement was not possible because of a failed Ivor Lewis operation in one case and duodenal atresia in the other.

• The Korean Journal of Pain
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• v.19 no.1
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• pp.123-126
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• 2006

Spinal cord stimulation (SCS) has been used since 1967 for refractory chronic pain. SCS has recently undergone a variety of technical modifications and advances, and it has been applied in a variety of pain conditions. SCS has been most commonly applied for those patients with chronic back and leg pain and failed back surgery syndrome (FBSS). The clinical hallmark of FBSS is chronic postoperative pain. The pain pattern varies and the pain may show an axial or radicular distribution. Chronic intractable pain after FBSS is difficult to treat. This report describes our experience with treating chronic pain in two patients who suffered from FBSS with a spinal cord stimulator. A permanent spinal cord stimulator was implanted after a successful trial of stimulation with temporarily implanted electrodes. After 5 months of follow-up, the two patients had satisfactory improvement of their pain.

• Clinics in Shoulder and Elbow
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• v.23 no.1
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• pp.48-58
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• 2020

Although the prevalence of rotator cuff tears is dependent on the size, 11% to 94% of patients experience retear or healing failure after rotator cuff repair. Treatment of patients with failed rotator cuff repair ranges widely, from conservative treatment to arthroplasty. This review article attempts to summarize the most recent and relevant surgical options for failed rotator cuff repair patients, and the outcomes of each treatment, except arthroplasty.

• The Korean Journal of Pain
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• v.27 no.1
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• pp.3-15
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• 2014

As our population ages and the rate of spine surgery continues to rise, the use epidural lysis of adhesions (LOA) has emerged as a popular treatment to treat spinal stenosis and failed back surgery syndrome. There is moderate evidence that percutaneous LOA is more effective than conventional ESI for both failed back surgery syndrome, spinal stenosis, and lumbar radiculopathy. For cervical HNP, cervical stenosis and mechanical pain not associated with nerve root involvement, the evidence is anecdotal. The benefits of LOA stem from a combination of factors to include the high volumes administered and the use of hypertonic saline. Hyaluronidase has been shown in most, but not all studies to improve treatment outcomes. Although infrequent, complications are more likely to occur after epidural LOA than after conventional epidural steroid injections.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.393-398
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• 1999

The main objective of this project is to define the ultimate bond performance of domestic prestressing strands in the precast prestensioned concrete beams. Eight specimens from four different companies were fabricated and tested in this study. Four-point loading tests were performed on the beams of domestic strands with an arbitrary anchorage length. The research has shown, that all seven specimens except one failed in bond are capable of developing their full flexural capacity and the strands within them are fully anchored even with the sudden transfer of frame cutting. Following results are summarized from the tests conducted. 1) All of the specimens are tested at an embedment lengths much shorter than those required by the ACI code, failed in flexure except one failed in bond. 2) It seems that the beam depth can not be an effective variable to estimate the bond length within these sections and length of specimens on this tests. 3) The development length with the stirrup space which are considered for correction factors in the equations of Russel and Paulsgrove, is fully accurate to determine the required length for the beam tested in this research.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.133-136
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• 2005

Experimental research was conducted to investigate the characteristic of various CFRP strengthening methods. A total of 4 specimens of 3.3m length were tested in four point bending after strengthening them with externally bonded CFRP plates. The CFRP plates were bonded without prestress or with prestress levels of CFRP plate strain $0.5\%$. The non-prestressed specimen without anchor plate failed by separation of the plate from the beam due to premature debonding while the non-prestressed specimen with anchor plate failed by CFRP fracture and showed the significant increase of ductility capacity. In addition, the prestressed specimens failed by concrete compression failure. The maximum load and ductility capacity were most significantly increased.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.3
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• pp.83-92
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• 2008

This paper develops the theory for a fault-tolerant, permanent magnet biased, homopolar magnetic bearing. If some of the coils or power amplifiers suddenly fail, the remaining coil currents change via a novel distribution matrix such that the same magnetic forces are maintained before and after failure. Lagrange multiplier optimization with equality constraints is utilized to calculate the optimal distribution matrix that maximizes the load capacity of the failed bearing. Some numerical examples of distribution matrices are provided to illustrate the theory. Simulations show that very much the same dynamic responses (orbits or displacements) are maintained throughout failure events (up to any combination of 3 coils failed for the 6 pole magnetic bearing) while currents and fluxes change significantly. The overall load capacity of the bearing actuator is reduced as coils fail. The same magnetic forces are then preserved up to the load capacity of the failed.