• Korean Journal of Construction Engineering and Management
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• v.12 no.6
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• pp.14-21
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• 2011

A unit modular system is a construction method which installs on site by manufacturing 50%~90% of the whole process in the factory. This method can minimize the process in the site and maximize the operation, which will reduce the duration and improve the overall quality. The recent paradigm of construction is to be sustainable building. Modular system can be regarded as a sustainable building construction method because it can reduce the amount of construction waste by recycling partial or whole part of overdue building be torn down. A unit modular system is the answer to cope with the increasing market of small size housings. A unit modular system is the most appropriate option at this point. This research proposes the standard operation and construction process of modular system, which enable to optimal system. A case study of reconstructing small-size housing was introduced to support this proposal. Finished unit modular is the reasonable way. However, 80% of complication rate of the modular is the most rational when a defect occurrence during delivery is considered.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.6
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• pp.25-31
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• 2004

In this paper, we introduce kinetic Monte Carlo (kMC) methods for simulating diffusion process in nano-scale device fabrication. At first, we review kMC theory and backgrounds and give a simple point defect diffusion process modeling in thermal annealing after ion (electron) implantation into Si crystalline substrate to help understand kinetic Monte Carlo methods. kMC is a kind of Monte Carlo but can simulate time evolution of diffusion process through Poisson probabilistic process. In kMC diffusion process, instead of. solving differential reaction-diffusion equations via conventional finite difference or element methods, it is based on a series of chemical reaction (between atoms and/or defects) or diffusion events according to event rates of all possible events. Every event has its own event rate and time evolution of semiconductor diffusion process is directly simulated. Those event rates can be derived either directly from molecular dynamics (MD) or first-principles (ab-initio) calculations, or from experimental data.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.4
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• pp.219-225
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• 2003

Purpose: Platelet Rich Plasma(PRP) application is increasing with sinus inlay bone graft, but there is few research with radiographic ananlysis on effect of PRP in maxillary sinus. The author investigated the amount of bony changes of maxillary sinus for dental implantation among the patients with maxillary inlay graft. Materials and Methods: With 10 patients who were treated with sinus inlay autologous bone grafting combined with PRP technique, and with 5 patients who were treated with sinus inlay grafting only without PRP, the panoramic radiographys which were taken at preoperation, immediate postoperation, 3months postoperation, and 4 months postoperation(a month after dental implantation)periods were analysed. The films had been scanned, and then proceeded throughout image analysis system. The bone density of maxillary grafted sites was compared with adjacent tooth enamel density and remeasured according to density luminosity of each film. The density changes on PRP group and bone graft only group were analysed with non-parameteric statistics method. Results: In PRP combined patients group, bone density on postoperation periods was increased totally. The remarkable enhanced change of bone density was observed on 3 months postoperation period, thereafter the increasing rate was slightly reduced. In only bone graft patients group, bone density on postoperation periods was also increased compared with preoperation period, but the bone density of 4 months postoperation period was decreased compared with 3 months postoperation period. The amount of bone density on PRP group was significantly changed according to periods in contrast to bone graft only group. Conclusion: The bone density on PRP group was remarkably increased at 3 months postoperation compared to bone graft only group and it was seemed to be associated with more new bone formation, less grafted bone resorption at bone grafted sites with PRP.

• Journal of Periodontal and Implant Science
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• v.25 no.3
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• pp.478-486
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• 1995

Periodontal therapy for treatment of periodontitis involves the elimination of bacterial plaque and elimination of the anatomic defects by regenerative procedure. The purpose of this study was to evaluate on the biological effect of magnolia and Ginkgo biloba extract to the antimicrobial, antiinflammatory and cellular activity. Antimicrobial assay was performed with the diffusion method of the extract by measuring of growth inhibitory zone of B. cereus from blood agar plate. Effect of the extract to cellular activity of gingival fibroblast were examined using MTT method and measured the result with optical density on 570nm by ELISA reader. Inhibitory effects of $PGE_2$ production from gingival fibroblast was performed with the addition of $IL-l{\beta}$ and the extract to the well and examined to the product of $PGE_2$ from cell by ELISA reader. In vivo anti-inflammatory effect was performed with injection examined with clinically and histologically for their extent of mecrosis and inflammation. Antimicrobial activity of Magnolia extract showed significantly higher activity than that of control. However, GBE did not showed significant activity to compare with control, and mixture of Magnolia and GBE extract showed significantly higher activity than that of control. The effect of cellular activity to gingival fibroblast showed no significant differences of between control and Magnolia extract. However, GBE showed significantly higher rate of cellular activity to compare with control and even to PDGF-BB, and also showed same degree of cellular activity even though mixed with Magnolia extract. The inhibitory effect of $PGE_2$ production showed significantly reduction of $PGE_2$ production to compare with control, but its inhibitory effect was not much strong to compare with Indomethacin. In vivo, antiinflammatory effect of Magnolia extract to P. gingivalis injection of Hamster buccal check showed significantly reduction of inflammatory cell infiltration and tissue necrosis, but GBE showed no effect on the inhibition of inflammatory process. These results suggested that Magnolia and GBE extract possessed different kind of biological activity and also can be compensated on their activity with each other for elimination of bacterial plaque and anatonical defect.

• Journal of the Korean Electrochemical Society
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• v.15 no.1
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• pp.27-34
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• 2012

$Li_3V_2(PO_4)_3$/carbon composite materials are synthesized from a sucrose-containing precursor. Amorphous $Li_3V_2(PO_4)_3/C$ (a-LVP/C) and crystalline $Li_3V_2(PO_4)_3/C$ (c-LVP/C) are obtained by calcining at $600^{\circ}C$ and $800^{\circ}C$, respectrively, and electrochemical performance as the negative electrode for lithium secondary batteries is compared for two samples. The a-LVP electrode shows much larger reversible capacity than c-LVP, which is ascribed to the spatial $Li^+$ channels and flexible structure of amorphous material. In addition, this electrode shows an excellent rate capability, which can be accounted for by the facilitated $Li^+$ diffusion through the defect sites. The sloping voltage profile is another advantageous feature for easy SOC (state of charge) estimation.

• Archives of Reconstructive Microsurgery
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• v.14 no.1
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• pp.1-13
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• 2005

Purpose: The purpose of this study is to present extended indications for the use of arterialized venous flaps in reconstructing soft tissue, tendon, nerve, blood vessel, and composite tissue defects of the hand of various sizes based on researches and clinical experiences of the authors. Moreover, procedures to achieve complete flap survival and postoperative results are presented. Materials & methods: This study is based on 154 cases of arterialized venous flaps performed to reconstruct the hand during the past 11 years. The most common cause of injury was industrial accidents with 125 cases. One hundred thirty patients or 84% of the cases had emergency operation within 2 weeks of the injury. The flaps were categorized depending on the size of the flap. Flaps smaller than $10\;cm^2$ were classified as small (n=48), those larger than $25\;cm^2$ classified large (n=42) and those in between medium (n=64). Classified according to composition, there were 88 cases (57.1 %) of venous skin flaps, 28 cases of innervated venous flaps, 15 cases of tendocutaneous venous flaps, which incorporated the palmaris longus tendon, for repair of extensor tendons of the fingers, and 17 cases of conduit venous flaps to repair arterial defect. There were 37 cases where multiple injuries to multiple digits were reconstructed. Moreover, there were 6 cases of composite tissue effects that involved soft tissue, blood vessels and tendons. The donor sites were ipsilateral forearm, wrist and thenar area, foot dorsum, and medial calf. The recipient sites were single digit, multiple digits, first web space, dorsum and palm of hand, and wrist. Results: There were seven cases (4.5%) of emergent re-exploration due to vascular crisis, and 3 cases of flap failure characterized by more than 50% necrosis of the flap. The survival rate was 98.1 % (151/154). In small flaps, an average of 1.01 afferent arteries and 1.05 efferent veins were microanastomosed, and in large flaps, an average of 1.88 afferent arteries and 2.19 efferent veins were anastomosed. In 8 cases where innervated flaps were used for reconstructing the palm of the hand, the average static two-point discrimination was $10\;(8{\sim}15)\;mm$. In 12 cases where tenocutaneous flaps were used, active range of motion at the proximal interphalangeal joint was 60 degrees, 20 degrees at the distal interphalangeal joint, and 75 degrees at the metacarpophalangeal joint. Conclusion: We conclude that the arterialized venous flap is a valuable and effective tool in the reconstruction of hand injuries, and could have a more comprehensive set of indications.

• Archives of Reconstructive Microsurgery
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• v.4 no.1
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• pp.58-64
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• 1995

The radial forearm flap was first designed at the Ba-Ba Chung Hospital of People's Republic of China in 1978. The flap consists of the skin of the volar surface of the forearm, the subcutaneous fat, the underlying fascia, and the intramuscular fascia which includes the radial vessels. It is very useful flap in soft tissue coverage of skin defects of the upper and lower extremities. The authors have reported 13 cases of forearm free flap treated in the Korea University Hospital from January 1991 to Jun 1995 with a review of literature. The results were as follows. 1. We had good results in soft tissue coverage for all patients 2. The average size of flaps was $54cm^2$ and the average ischemic time of flaps was 74minutes. 3. The postoprative complication was occurred in three of 13 cases, two of three cases were arterial thrombosis treated with thrombectomy in postoperative 2 days, and one case was venous thrombosis resulted in superficial necrosis of the flap treated with STSG. 4. Forearm free flap with sensory innervation is a good donor site for reconstruction of weight-bearing areas of heel and sole. 5 The forearm free flap is suitable for soft tissue coverage of the upper and lower extremities, and can be used by skillful microsurgeon with high success rate.

• 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

• Journal of Yeungnam Medical Science
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• v.11 no.1
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• pp.146-152
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• 1994

We performed the same day dipyridamole stress/rest myocardial SPECT in 14 healthy young men, reconstructed the polar maps according to Cedars-Sinai method and quantitated the radioactivity of myocardial wall. We divided the whole myocardium to 9 sectors. The latero-anterior wall contains the highest count. The infero-septal wall contains the lowest count. There isn't any significant differences of radioactivity in each segment between stress and rest polar map. The hemodynamic parameters after dipyridamole injection in the subjects were significantly changed except systolic blood pressure : the heart rate was increased and diastolic blood pressure was decreased. Adverse effects were reported in 85.7%. We suggest that these data can be used to dectect perfusion defect in the coromary artery disease.

• Composites Research
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• v.29 no.3
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• pp.117-124
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• 2016

The failure strength of composite single-lap joint repaired using scarf patch was investigated by test and finite element method. A total of 45 specimens were tested changing scarf ratio, stacking pattern, and defect size to study the failure strength and mode. Except for one case, all repaired specimens showed the equal or higher strength than the sound specimens and the effect of considered repair parameters was not remarkable. It was found through the failure mode inspection that the surface treatment for bonding was not enough in the case which failed at the lower load than the sound specimen. Three-dimensional finite element analysis was conducted to verify the test results. It was confirmed that the considered repair parameters do not significantly affect the stress distribution of the specimens. It was also observed that the applied tensile load is relieved passing through the overlapped region thickness of which is almost double. From this study, it is concluded that if the bonding procedure for adherends and patch including surface treatment for fabric layer is thoroughly followed, the strength of repaired single-lap joint can be restored up to the strength of sound one.