• Archives of Plastic Surgery
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• v.33 no.3
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• pp.289-293
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• 2006

By means of microsurgical free-tissue transfer providing a large amount of required tissue, the surgeon can resect tumoral tissue more safely, which allows tumor-free margins and enhances the reliability of the ablative surgery that otherwise could not be performed radically. The morbidity of elective free-tissue transfer seems to be quite low, carrying acceptable risks for most patients. But the elderly patients are at risk for cardiac and respiratory problems, deep vein thrombosis, pulmonary emboli and infection merely as a function of age. This study was undertaken to define further risks of the elderly population with regards to free-tissue transfer. We retrospectively reviewed our experience with 110 microsurgical free-tissue transfers for head and neck reconstruction in patients greater than 60 years of age. Microsurgical procedures in all cases were preformed by the plastic and reconstructive department at Yonsei medical center. The investigated parameters were patient demographics, past medical history, American Society of Anesthesiologists(ASA) status, site and cause of defect, the free tissue transferred and postoperative complication including free-flap success or failure. There were 46 patients in the age group from 60 to 64 years, 34 patients from 65 to 70 years, and 30 patients 70 years or older. There happened 3 flap losses, resulting in a flap viability rate of 97%. Patients with a higher ASA designation experienced more medical complication(p=0.05, 0.01, 0.03 in each age group I, II, III) but not surgical complication p=0.17, 0.11, 0.54 in each age group I, II, III). And the relationship between postoperative complication and age groups was not significant. These observations suggest that major determinant for postoperative medical complication be the patient's American Society of Anesthesiologists score, and chronologic age alone should not be an exclusion criterion when selecting patients for free-tissue transfer

• Archives of Reconstructive Microsurgery
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• v.21 no.1
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• pp.56-60
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• 2012

Purpose: Thumb reconstruction plays most important role in hand injuries because total loss of a thumb constitutes about 40% disability in the hand. The reconstruction can be accomplished by pollicization, free toe-to-thumb transfer, wrap around procedure and lengthening extraction. However, we sometimes need consecutive or double free flaps in the reconstruction of mutilating hand injuries. Methods: We reconstructed a mutilating hand injury in a 54-years old man. Because of severe crushing injury of right thumb and index fingers, we reconstructed a thumb with pollicization using nearly amputated middle finger. Although it survived completely, the adjacent soft tissues which had been covered by fillet flap from the space past was necrosed on 1 month. We debrided the necrotic tissues and covered it with anteromedial thigh perforator free flap consecutively because he had an anatomical variation in branches of lateral femoral circumflex artery. Results: He had an uneventful postoperative course without any complication such as infection, dehiscence and flap necrosis. Three months later, he had undergone tenolysis and defatting procedure of flap site. He recovered the some amount of grip function and was happy with the result. Conclusion: In severe hand trauma including thumb amputation, thumb reconstruction using pollicization and perforator free flap could be an alternative option. It provides minimal donor site morbidity and an acceptable functional result.

• Water for future
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• v.15 no.3
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• pp.23-36
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• 1982

The stochastic variations and structures of time series data on water quality were examined by employing the techniques of autocorrelation function, variance spectrum, Fourier series, autoregressive model and ARIMA model. These time series included hourly and daily observation on DO, turbidity, conductivity pH and water temperature. The measurement was made by automatic recording instrument at Noryangjin and Dook-do located in the downstream part of Han River during 1975 and 1976. Hourly water quality time series varied with the dominant 24-hour periodicity, and the 12-hour periodicity was also observed. An important factor affecting 24-hour periodic variation of DO is believed to be photosynthesis by algae. These phenomena might be attributable to periodic discharges of municipal sewage. Noryangjin site showed the more distinct 12-hour periodicity than Dook-do site did, and tidal effect might be responsible for the difference. The water quality, as measured by DO and turbidity, was better in the afternoon compared with the quality in the morning. This change can be explained by the periodic variation of DO, temperature and the amount of municipal wewage discharge. It was also observed that the water temperature at Noryangjin was higher than the temperature at Dook-do. This difference might have been caused by the pollutants that were added to the section between two sites. The correlation coefficients between some of the variables were fairly high. For example, the coefficient was -0.88 between DO and water temperature, 0.75 between turbidity and river flow, and 0.957 between water temperature and air temperature. The lag time of heat transfer from the air to the water was estimated as 24 days. The first order auto-regressive model was appropriate for explaning standardized hourly DO time series. The ARIMA model of (1, 0, 0) type provided relatively satisfactory results for daily DO time series after the removal of significant harmonic value.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1877-1882
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• 2007

The Yongsan International Business District development work is a 20 billion$ project to raise facilities for national business, trade, residence, and culture. The project site is $566,800m^2$ and it covers the railroad maintenance center and Dongbuichon-dong. Developing railroad station region used to be done by private investment. However, problems existed; simple function as a massive selling market, traffic jam caused by massive market users, inadequacy to transfer to other transportations, interruption of the pedestrian way and separation of zone of life by the station. To solve this problem it is important to consider developing cases of other countries and devise a plan that is applicable to our circumstances. In the study, we compared our station development case with foreign station development cases and analyze the element for the plan what we should consider in our station development. In addition, The results of the study can be used as a preliminary data in the future planning the Yongsan International Business District development.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.5
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• pp.101-105
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• 2013

This paper addresses QoS functions in mobile backhaul network to accommodate the diverse traffics in cell site. The traffics assigned to the switching function in RAN system, such as Ethernet frame, IP packet, and ATM cell, are segmented, and then encapsulated to transfer then to the mobile backhaul network. ISP can converge all generation traffics, such as voice, HSPA, over all-IP RAN through standard pseudowire encapsulation. These can be enhanced with diverse QoS methods as well as comprehensive monitoring and diagnostic capabilities. Therefore in this paper, QoS functions under theses operations is simulated according to the encapsulation functions.

• Geomechanics and Engineering
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• v.6 no.6
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• pp.531-544
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• 2014

Studies of earthquakes over the last 50 years and the examination of dynamic soil behavior reveal that soil behavior is highly nonlinear and hysteretic even at small strains. Nonlinear behavior of soils during a seismic event has a predominant role in current site response analysis approaches. Common approaches to ground response analysis include linear, equivalent linear and nonlinear methods. These methods of ground response analysis may also be categorized into time domain and frequency domain concepts. Simplicity in developing analytical relations and accuracy in considering soils' dynamic properties dependency to loading frequency are benefits of frequency domain analysis. On the other hand, nonlinear methods are complicated and time consuming mainly because of their step by step integrations in time intervals. In part Ι of this paper, governing equations for seismic response analysis of surcharged and layered soils were developed using fundamental of wave propagation theory based on transfer function and boundary conditions. In this part, nonlinear seismic ground response is analyzed using extended HFTD method. The extended HFTD method benefits Newton-Raphson procedure which applies regular iterations and follows soils' fundamental stress-strain curve until convergence is achieved. The nonlinear HFTD approach developed here are applied to some examples presented in this part of the paper. Case studies are carried in which effects of some influencing parameters on the response are investigated. Results show that the current approach is sufficiently accurate, efficient, and fast converging. Discussions on the results obtained are presented throughout this part of the paper.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.16 no.2
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• pp.113-121
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• 1994

Large oral defects following tumor resection pose formidable challenge for the reconstructive surgeon. Ideally, wound closure should utilize like tissue in providing expedient, single-stage closure, returning maximum function while minimizing deformity. Recent methods have reported and utilize variable mucocutaneous flaps. However, the ideal reconstruction has yet to defined. The small bowel serves as a readily available donor site for satisfying reconstructive needs in oropharyngeoesophageal defects. Segments of jejunum may be opened along the antimesenteric border and transferred to oral defect as free tissue transfers. Some of the benefits of this technique have included a one-stage procedure, abundant donor tissue with characteristics similar to oral mucosa, near normal facial appearance, preservation of maximum tongue function and relief of annoying xerostomia by jejunal mucous secretion. Three cases re presented in which two cases show successful use of this flap. The other one patient developed total necrosis of this flap. We report cases of reconstruction using free jejunal flap transfer in oral reconstruction.

• Journal of Life Science
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• v.14 no.5
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• pp.752-760
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• 2004

The function of the [4Fe-4S] cluster containing iron (Fe-) protein in nitrogenase catalysis is to serve as the nucleotide-dependent electron donor to the MoFe protein which contains the sites for substrate binding and reduction. The ability of the Fe protein to function in this manner is dependent on its ability to adopt the appropriate conformation for productive interaction with the MoFe protein and on its ability to change redox potentials to provide the driving force required for electron transfer. The MgADP-bound (or off) conformational state of the nitrogenase Fe protein structure described reveals mechanisms for long-range communication from the nucleotide-binding sites to control affinity of association with the MoFe protein component. Two pathways, termed switches I and II, appear to be integral to this nucleotide signal transduction mechanism. In addition, the structure of the MgADP bound Fe protein provides the basis for the changes in the biophysical properties of the [4Fe-4S] observed when Fe protein binds nucleotides. The structures of the nitrogenase Fe protein with defined amino acid substitutions in the nucleotide dependent signal transduction pathways of the Switch I and Switch II have been determined by X-ray diffraction methods. These two pathways have been also implicated by site directed mutagenesis studies, structural analysis and analogies to other proteins that utilize similar nucleotide dependent signal transduction pathways. We have examined the validity of the assignment of these pathways in linking the signals generated by MgATP binding and hydrolysis to macromolecular complex formation and intermolecular electron transfer. The results provide a structural basis for the observed biophysical and biochemical properties of the Fe protein variants and interactions within the nitrogenase Fe protein-MoFe protein complex.

• Korean Journal of Heritage: History & Science
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• v.52 no.2
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• pp.122-141
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• 2019

This study aimed to provide new interpretations of the ceramics excavated from the archaeological site of the royal palace of Goryeo (918~1392), where only limited access was permitted due to its location in Gaeseong, North Korea. The interpretations were based on the existing understanding of the arrangement of the palace buildings at the site and historical records. The study of the general aspects of the celadons discovered during eight excavations at the Goryeo Palace site in Gaeseong revealed that most of the vessels found at the site were produced during the early and middle phases of the Goryeo dynasty. The study involved classifying the celadons bearing inscribed texts and symbols into 18 different types according to their characteristic features and periods of production. The inscribed celadons have provided detailed information of the site where they were found, thereby making it possible to make strong presumptions about the date of construction, function, and status of the building in the palace connected with the discoveries. The excavations from the Goryeo Palace site and related historical literature suggest that the celadons bearing the inscription "Sojeon (燒錢)" were used during the first half of the 13th century, although the existing view had been that they were used during the second half of the century. This new conclusion is based on the use of the symbols ${\circ}$ and ${\odot}$, the celadons found together with the Sojeon-inscribed celadons, the date of the celadons bearing the inscription "Seong (成)," and the location of their discovery behind the site of Seongyeongjeon (aka Hoegyeongjeon) Hall, which had been one of the main palace buildings. The Taoist rituals performed for the safety of the Goryeo dynasty were largely held at Ganganjeon (aka Daegwanjeon) Hall in the western part of the royal palace during the second half of the 13th century. It was mostly in the first half of the 13th century just before the transfer of the Goryeo government from Gaeseong to Ganghwa (1232~1270) that the Taoist rituals were held at the location near Seongyeongjeon Hall, where archaeologists found the Sojeon-inscribed celadons. Therefore, the large number of celadon cups with holders, including those inscribed with Sojeon, discovered during the eighth excavation of the palace site suggests that they were used for the rituals held at Seongyeongjeon Hall during the first half of the 13th century.

• Archives of Reconstructive Microsurgery
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• v.6 no.1
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• pp.73-79
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• 1997

Complete denervation after severe brachial plexus injury make significant muscle atrophy with loss of proper function. It is much helpful to reconstruct the essential function of the elbow flexion movement in patient with total loss of elbow flexion motion after brachial plexus lesion which was not recovered with nerve surgery or long term conservative treatment from onset. In whole arm type brachial plexus injury, if there were no response to neurotization or neglected from injury, the volume of the denervated muscle is significantely reduced month by month. About 18 months most of the muscle fibers change to fibrous tissues and markedly atrophied irreversibly, further waiting is no more meaningful from that period. Authors performed 14 cases of functioning gracilis muscle transfer from 1981 to 1995 with microneurovascular technique, neuromusculocutaneous free flaps were performed for reconstruction of lost elbow flexion function. Average follow-up period was 5 years and 6 months. We used couple of intercostal nerves as a recipient nerve which were anastomosed to muscular nerve from obturator nerve in all cases. Recipient vessels were three deep brachial artery and eleven brachial artery which were anastomosed to medial femoral circumflex artery with end to end or end to side fashion. Average resting length of the transplanted gracilis were 24 cm. We can get average 54 degree flexion range of elbow with fair muscle power from flail elbow. There were one case of muscle necrosis with lately developed thrombosis of microvascular anastomosed site which comes from insufficient recipient arterial condition, 3 cases of partial marginal necrosis of distal skin of the transplanted part which were not significant problem with spontaneously solved with time goes by gracilis muscle has constant neurovascular pattern with relatively easy harvesting donor with minimal donor morbidity. Especially it has similar length and shape with biceps brachii muscle of upper arm and longer nerve pedicle which can neurorrhaphy with intercostal nerve without nerve graft if sufficient mobilization of the nerves from both sides of gracilis and intercostal region. Authors can propose gracilis muscle transplantation with intercostal nerves neurotization is helpful method with minimal donor morbidity for neglected brachial plexus palsy patients.