• Journal of the Korean Arthroscopy Society
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• v.16 no.2
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• pp.153-159
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• 2012

Purpose: This study aims at evaluating our results with a 5-year follow up of arthroscopic pull-out suture repair of posterior root tear of the medial meniscus. Materials and Methods: This study enrolled 30 cases who underwent a arthroscopic pull-out suture repair to treat the posterior root tear of the medial meniscus from January 2001 to May 2005 and followed up at least 5 years. The average follow-up period was 76 months (range, 60-90 months). Clinical results by use of the Lysholm knee score and radiographic grade by use of the Kellgren-Lawrence classification were evaluated and second-look arthroscopy was done in all cases. The clinical results were compared with trauma history, obesity, varus deformity and time to operation. Results: At the last follow up, the Lysholm knee score improved from 55 points to 86 points. For the radiological results, 23 cases displayed maintenance or improvement of the medial joint space on the follow up X-ray, but 7 cases displayed decrease of the medial joint space, and 1 case was lately performed total knee replacement due to progressive osteoarthritic change. Conclusion: Arthroscopic pull-out suture repair has a good result at 27 cases (90%) in minimum 5 years follow-up. The clinical improvement was significantly reduced in more severe varus angle.

• Journal of the korean academy of Pediatric Dentistry
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• v.21 no.2
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• pp.533-539
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• 1994

The mandibular buccal frenum is a fold of mucous membrane at the posterior labial vestibule, that attaches the lips and the cheeks to the alveolar mucosa, gingiva, and underlying periosteum. The buccal frenum becomes a problem if its attachment is too close to the marginal gingiva. It may then pull on healthy gingiva, encourge plaque formation and interfere with tooth brushing. Heavy buccal frenum mucogingivally results in insufficient attached gingiva, inadequate vestibular depth and high frenum attachment and also difficulty in eruption of mandibular second premolar. Frenectomy in various forms has been used for many years to remove the influence of the frenum. Unfortunately, the results are not always ideal and there is often postoperative relapse because of muscle pull. In this treatment, frenotomy was used in conjuction with autogenous free gingival graft with the object of removing the influence of the buccal frenum and creating an adequate and stable width of attached gingiva. We observed decrease in muscle pull, adequate width of attached gingiva and increased vestibular depth in addition to progressive eruption of second premolar. Periodic follow-up is needed for evaluation of relapse, grafting gingiva and also space regaining for second premolar.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.478-481
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• 2004

An experimental investigation on the relationship between corrosion of reinforcement and bond strength in pull-out test specimen has been conducted to establish the allowable limit of rust of reinforcement in the construction field. The reinforcing bars used in this study were rusted before embedded in pull-out test specimen. The first component of this experiment is to make reinforcing bar rust electrically based on Faraday's theory to be 2, 4, 6, 8 and $10\%$ of reinforcing bar weight. For estimation of the amount of rust by weight, Clarke's solution and shot blasting were adopted and compared. Parameters also include 24 and 45MPa of concrete compressive strengths and diameter of reinforcing bar (16, 19 and 25mm). Pull-out tests were carried out according to KS F 2441 and ASTM C 234. Results show that up to $2\%$ of rust increases the bond strength regardless of concrete strength and diameter of reinforcing bar. As expected, the bond strength increases as compressive strength of concrete increases and the diameter of bar decreases.

• Journal of Power Electronics
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• v.11 no.5
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• pp.632-638
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• 2011

This paper presents a cascaded coil flux control based on a Current Source Parallel Resonant Push-Pull Inverter (CSPRPI) for Induction Heating (IH) applications. The most important problems associated with current source parallel resonant inverters are start-up problems and the variable response of IH systems under load variations. This paper proposes a simple cascaded control method to increase an IH system's robustness to load variations. The proposed IH has been analyzed in both the steady state and the transient state. Based on this method, the resonant frequency is tracked using Phase Locked Loop (PLL) circuits using a Multiplier Phase Detector (MPD) to achieve ZVS under the transient condition. A laboratory prototype was built with an operating frequency of 57-59 kHz and a rated power of 300 W. Simulation and experimental results verify the validity of the proposed power control method and the PLL dynamics.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.15 no.25
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• pp.63-74
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• 1992

This study proposes D- shortage control system which is a convenient tool for cooperative companies to reduce shortages which frequently break out between the manufacturing companies and the cooperative companies. On the ground of theoretical analysis of MRP and JIT system, D- shortage control system sets up a schedule that secures the delivery date by precedent scheduling( D-) comparing with MRP It also syncronizes business, production and release, and builds the pull system comparing with JIT. The factors causing shotages are the scheduling absurdity and the controlling absurdity. The scheduling absurdity can be settled by the calculating required quantity method of MRP and the controlling absurdity can be settled by daily control of business, production and pruchasing fuctions by the pull system of JIT. And the inventory and the WIP can be reduced by the operating of PULL system and by the settlement of D- shortage control practices. The Application of D- shortage control system, therefore, enables the rationalization of logistics and reduces the inventory And it leads to the reinforced competitiveness and the security of subsistence of manufacturer by the cost ruduction, the reduction of financial difficulty, and the insurance of the delivery date.

• Archives of Plastic Surgery
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• v.46 no.3
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• pp.277-281
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• 2019

Recto-vaginal fistulas are difficult to treat due to their high recurrence rate. Currently, no single surgical intervention is universally regarded as the best treatment option for recto-vaginal fistulas. We present a case of recurrent recto-vaginal fistula surgically treated with a gracilis pull-through flap. The surgical goals in this patient were complete excision of the recto-vaginal fistula and introduction of fresh, vascularized muscle to seal the fistula. A defunctioning colostomy was performed 1 month prior to the present procedure. The gracilis muscle and tendon were mobilized, pulled through the freshened recto-vaginal fistula, passed through the anus, and anchored externally. Excess muscle and tendon were trimmed 1 week after the procedure. Follow-up at 4 weeks demonstrated complete mucosal coverage over an intact gracilis muscle, and no leakage. At 8 weeks post-procedure, the patient resumed sexual intercourse with no dyspareunia. At 6 months post-procedure, her stoma was closed. The patient reported transient fecal staining of her vagina after stoma reversal, which resolved with conservative treatment. The fistula had not recurred at 20 months post-procedure. The gracilis pull-through flap is a reliable technique for a scarred vagina with an attenuated recto-vaginal septum. It can function as a well-vascularized tissue plug to promote healing.

• Advances in pediatric surgery
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• v.10 no.1
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• pp.1-8
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• 2004

A re-pull-through operation for Hirschsprung's disease is performed when the primary operation has failed because of the remnant or acquired aganglionosis, anastomotic stricture and/or fistula. The purpose of this study is to review our experience of the re-pull-through procedure for Hirschsprung's disease. From May 1978 to July 2003, 26 patients who underwent re-pull-through operations at the Department of Pediatric Surgery, Seoul National University Children's Hospital, were studied retrospectively by means of chart review as well as telephone interview. The mean age at primary operation and re-operation were llmonths (2 months - 10 years) and 43 months (1 year - 23 years 3 months), respectively. Initial operation for Hirschsprung's disease was Duhamel's procedure in 17, Swenson's in 6 and Soave's 3. Causes of failure of primary operation were remains of secondary aganglionic segment (n=23), vascular arcade injury (n= 1), rectoperineal fistula (n=2, due to mesenteric torsion and poor blood supply), Mean interval between the primary operation and the re-operation was 34 months (6 months-22 years). Reoperation methods were Soave's in 12, Duhamel's in 8, APSP (abdomino-posterosagittal pull-through procedure) in 5, and Swenson's in 1 case. In 2 cases of repeated rectoperineal fistula or rectourethral fistula, re-APSP were performed 3 times, respectively. A total of 29 re-pull-through operations were performed. Postoperative complications were wound infection (n=1), adhesive ileus (n=1), rectoperineal fistula (n=3), rectourethral fistula (n=2), and death due to pulmonary embolism (n=1). Mean follow up period of reoperation was 78 months (1 month-23years). In current state, 2 patients have an ileostomy because of repeated rectoperineal fistula and rectourethral fistula. Of the remaining 23 patients, 21(91 %) are totally continent with or without minimal soiling. Reoperation for Hirschsprung's disease was effective and safe for the patients complicated to the initial pull-through operation.

• Korean journal of applied entomology
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• v.58 no.3
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• pp.209-218
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• 2019

This study was conducted to develop a technology for environmentally friendly control of sweet-potato whitefly, Bemisia tabaci, by controlling their behavior using a push-pull strategy in a tomato greenhouse. B. tabaci was attracted the most by yellow color, light source of 520 nm, whereas it avoided the complex light treatment of 450 + 660 nm. The two natural enemies of B. tabaci, Cyrtopeltis tenuis and Orius laevigatus, were attracted the most by 520 nm light source. B. tabaci was repelled by the volatile organic compounds ocimene and carvacrol and was the most attracted by methyl isonicotinate. When buckwheat was added into the tomato greenhouse, the density of C. tenuis was maintained at about 16 times higher than when untreated for 15 days. As a result of the combined treatment of push-pull strategy, the density per trap of B. tabaci was three times lower than when no treatment was applied, and the control of this pest increased with time and reached up to 68.7%.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.5
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• pp.889-896
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• 2020

In general, there are various types of boost converters such as Boost converters, Buck-Boost converters, Flyback converters, Push-Pull converters, etc. Among them, Boost converters are the most widely used and step up converters in a very simple form. However, Boost converter has DCM mode operation, big ripple problem and RHPZ problem. In order to solve these problems, a converter to which the new topology was applied was presented, but among them, the KY converter improved the Boost converter's DCM mode operation, the big ripple problem and the RHPZ problem. However, the conventional KY converter has a drawback that the voltage gain is relatively lower than that of the Boost converter. Therefore, in this paper, we proposed a new KY converter that solves the problem of low voltage gain while having the advantages of the conventional KY converter.

• International Journal of Aeronautical and Space Sciences
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• v.12 no.1
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• pp.84-91
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• 2011

A finite element analysis for the wing and landing gear of a composite target-drone air vehicle was performed. For the wing analysis, two load cases were considered: a 5g symmetric pull-up and a -1.5g symmetric push-over. For the landing gear analysis, a sinking velocity of 1.4 m/s at a 2g level landing condition was taken into account. MSC/NASTRAN and LS-DYNA were utilized for the static and dynamic analyses, respectively. Finite element results were verified by the static test of a prototype wing under a 6g symmetric pull-up condition. The test showed a 17% larger wing tip deflection than the finite element analysis. This difference is believed to come from the material and geometrical imperfections incurred during the manufacturing process.