• Archives of Craniofacial Surgery
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• v.11 no.1
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• pp.53-57
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• 2010

Purpose: The radial forearm fasciocutaneous free flap is currently considered as the ideal free flap for reconstruction of mucosal and soft tissue defects of the palate. But the availability of stably attached oral and nasal mucosal lining is needed. In addition to this, for better operation field, operating convenience and esthetics, we planned a prelaminated radial forearm free flap. Methods: A 64-year-old male patient was admitted due to a $4{\times}4.5cm$ full through defect in the middle of the hard palate caused by peripheral T cell lymphoma with actinomycosis. In the first stage, the radial forearm flap was elevated, tailored to fit the hard palate defect, and then it positioned up-side down with split thickness skin graft. Two weeks later, the prelaminated radial forearm free flap was re-elevated and transferred to the palatal defect. One side covered with grafted skin was used to line the nasal cavity, and the other side (the cutaneous portion of the radial forearm flap) was used to line the oral cavity. Results: The prelamination procedure was relatively easy and useful. The skin graft was well taken to the flap. After 2nd stage operation, the flap survived uneventfully. There was no prolapse of the inset flap into the oral cavity and the cutaneous portion of the flap was mucosalized. The procedure was very successful and the patient can enjoy normal rigid diet and speech. Conclusion: The use of prelaminated radial forearm free flap for hard palate reconstruction is an excellent method to restore oral function. Based upon the result of this case, microvascular free flap transfer with prelaminated procedure is a valid alternative to the prosthetic obturator for palatal defect that provides an improved quality of life. It should be considered as an integral component of head and neck cancer therapy and rehabilitation.

• Journal of Korean Society of Steel Construction
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• v.25 no.6
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• pp.601-612
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• 2013

In the present study, details of the TSC beam-to-PSRC column connection for low and middle seismic zones were developed. For ease construction, the top and bottom flanges of the steel section of the TSC beam were discontinuous at the joint face on purpose, while the web passes through the joint. Thus, tensile resistance of the top and bottom flanges is not considered in the calculation of nominal strength of the connection. Cyclic loading tests on two interior connections and an exterior connection were performed to verify the seismic performance. The test parameter for two interior connections was the depth of the TSC beams: 600 and 700 mm including the slab depth. The test results showed that the nominal strength of the connections predicted by KBC 2009 correlated well with the test results. The connection specimens exhibited relatively good deformation and energy dissipation capacities, greater than the requirements for the ordinary and intermediate moment frames. Ultimately, the connection specimens were failed at the story drift ratios of 3.0 to 4.0 % due to local buckling and tensile fracture of the web of the TSC beam passing through the joint. By modifying the existing provisions of ASCE, the joint shear strength of the TSC beam-PSRC column connection was evaluated.

• Journal of the Earthquake Engineering Society of Korea
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• v.15 no.6
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• pp.55-66
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• 2011

The purpose of this study was to develop an efficient process in the design and construction of a 1:5 scale 10-story R.C. apartment building model for an earthquake simulation test. The reduction ratio of the specimen was determined by the size ($5m{\times}5m$) and pay load (600kN) of the available shaking table and the availability of model reinforcements. For efficiency and quality control of the reinforcement work, prefabrication was used. Construction was conducted in two steps, the wall in one step, and another step for the slab, because it was impossible to remove the formwork of a wall if the walls and slabs in a story were constructed in one step. The slip form construction method was used repetitively for walls. The formwork of a wall was made with veneer and acryl plate on each side, so it was possible to check the quality of the concrete placing. To construct this model, it took roughly six months with five full-time research assistants, for a total of 602 man days of labor in construction.

• Archives of Reconstructive Microsurgery
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• v.13 no.2
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• pp.93-100
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• 2004

This study was designed to investigate the optimal period of pedicles implantation in the prefabricated periosteofascial flap with a vascular tissue transfer. The flap prefabrication was prepared with a transposition of left occipital pedicles on the calvarial fascia of male Sprague-Dawley rats. Thirty flaps were divided into five groups of six flaps, including control group (group I) of the conventional periosteofascial flap based on the lateral border of the rat calvarium. The prefabricated flap was elevated as an $1{\times}1cm$ sized island flap based on the implanted pedicle at 1, 2, 3, and 4 weeks after the pedicles transfer in groups II, III, IV, and V, respectively. After the completion of creating a critical-sized calvarial defect and implanting with hydroxyapatite granules, the flap was sutured back for covering the defect and kept isolated from surrounding tissues. Six weeks after flap repositioning, the osseous changes of the defect were examined with simple radiographic findings, radiodensitometric analysis, and histological studies. By simple radiographic findings, specimens of the control, groups IV and V showed homogeneous radioopacity within the defect. But in groups II and III, focal radiolucency was observed in the defect. In the radiodensitometric analysis, the control group and the group V showed significant increased radiodensites statistically. Histologically, the implanted hydroxyapatite was absorbed partly in the defect in groups II, III, and IV. In the defects of the control group and the group V, the implanted hydroxyapatite was kept in its volume and the deposition of the bone cells was observed sparsely. In conclusion, the prefabricated periosteofascial flap can be created with a vascular tissue transfer and the pedicles should be implanted at least for 4 weeks to bring out positive osseous changes in the calvarial defect.

• Journal of the Korean Wood Science and Technology
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• v.28 no.4
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• pp.41-50
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• 2000

Cement-bonded particleboard is being used as outdoor siding material all over the world, because this composite particularly bears a light weight, high resistance against fire, decay, and crack by cyclic freezing and thawing, anti-shock property, and strength enhancement. Construction systems are currently changing into a frame-building style and wooden houses are being constructed with prefabrication type. Therefore, they require a more durability at outdoor-exposed sides. In this study, the cement hydration property for Korean pine particle, Japanese larch particle and face- and middle layer particles (designated as PB particle below) used in Korean particleboard-manufacturing company was investigated, and the rapid manufacturing characteristics of cement-bonded particleboard by supercritical $CO_2$ curing was evaluated. Korean pine flour showed a good hydration property, however, larch flour showed a bad one. PB particle had a better hydration property than larch flour. The addition of $Na_2SiO_3$ indicated a negative effect on hydration, however, $MgCl_2$ had a positive one. Curing by supercritical $CO_2$ fluid gave a conspicuous enhancement in the performances of cement-bonded particleboards compared to conventional curing. $MgCl_2$ 3%-added PB particle had the highest properties, and $MgCl_2$ 1%-added Korean pine particle had the second class with the conditions of cement/wood ratio of 2.7, a small fraction-screened particle and supercritical curing. On the contrary, the composition of non-hammermilled or large fraction-screened particle at cement/wood ratio of 2.2 was poorer. Also, the feasibility for actual use of 3%-added, small PB particle-screened fraction was greatest of all the conventional curing treatments. Relative superiority of supercritical curing vs. conventional curing at dimensional stability was not so apparent as in strength properties. Through the thermogravimetric analysis, it was ascertained that the peak of a component $CaCO_3$ was highest, and the two weak peaks of calcium silicate hydrate and ettringite and $Ca(OH)_2$ were present in supercritical treatment. Accordingly, it was inferred that the increased formation of carbonates in board contributes to strength enhancement.

• Korean Journal of Construction Engineering and Management
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• v.24 no.3
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• pp.12-19
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• 2023

In the case of the construction industry, the relationship between process and cost should be appropriately distributed so that the finished product can be delivered at the minimum fee within the construction period. At that time, it should be considered the size of the bridge, the construction method, the environment and production capacity of the factory, and the transport distance. However, due to various reasons that occur during the construction period, problems such as construction delay, construction cost increase, and quality and reliability degradation occur. Therefore, a systematic and scientific construction technique and process management technology are needed to break away from the conventional method. The prefab(Pre-Fabrication) is a representative OSC (Off-Site Construction) method manufactured in a factory and constructed onsite. This study develops a resource and process plan optimization system for the process management of the Nodular girder, a prefab bridge girder. A simulation algorithm develops to automatically test various variables in the personnel equipment mobilization plan to derive the optimal value. And, the algorithm was applied to the Paju-Pocheon Expressway Construction (Section 3) Dohwa 4 Bridge under construction, and the results compare. Based on construction work standard product calculation, actual input manpower, equipment type, and quantity were applied to the Activity Card, and the amount of work by quantity counting, resource planning, and resource requirements was reflected. In the future, we plan to improve the accuracy of the program by applying forecasting techniques including various field data.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6D
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• pp.969-974
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• 2006

Labor shortages are a serious problem for Korea's construction industry. The problem is both quantitative and qualitative. There is a shortage in supply as due to a decrease in the influx of new labor, and existing workers are less productive as they age. The problem will only get worse as more and more major public projects are being planned. Options for increasing the labor supply are somewhat limited, and thus efforts need to be made to adopt new technologies that can improve the productivity and efficiency of field work and their processes. This paper introduces seven innovation technologies that have the best potential to increase productivity and thus reduce the burden of labor shortage problems. These include 1) Substitution by use of robotics and automation, 2) development and applications of Innovative materials to reduce on site field work, 3) increase in productivity through the implementation of Information Technology, 4) improved productivity through the application of modules, and prefabrication, 5) prevention of rework and redesign, 6) diversification of labor by integrating labor skills, and 7) improved productivity by standardizing site processes.

• Journal of Oral Medicine and Pain
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• v.32 no.3
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• pp.283-292
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• 2007

In several treatment modalities for snoring and obstructive sleep apnea (OSA), oral appliances mainly including mandibular advancement appliance (MAA) and tongue retaining device (TRD) are recognized as a non-invasive, reversible alternative with favorable results. Tongue bulb is a major component of TRD which prevents the tongue from approaching the posterior wall of the pharynx and can be combined with MAA. Determination of tongue bulb size for the patient is important for therapeutic effect, but frequently needs time-consuming work. For effective fabrication and standardization of tongue bulbs, this study aimed to categorize tongue bulb size for healthy young men and to examine its relation with maximum retention force and with physical parameters including tongue-related variables. 36 non-snoring, asymptomatic young men with normal occlusion were voluntarily participated in this study (mean age: $24.47{\pm}2.58$ years). Experimental procedures consisted of prefabrication of tongue bulb set (20 types with a width of 27-36mm and thickness of 8 and 10 mm), determination of tongue bulb size and the maximum retention force for each subject, and measurement of physical parameters including body mass index (BMI), neck circumference and width, thickness and length of tongue. This study showed that there was significant difference of retention force among the bulb size-related groups both in upright and supine position (p<0.05) and that retention force increased with bulb size. Correlation of tongue bulb size with physical parameters was not clearly verified and there was no significant difference in retention force between upright and supine positions. Based on our results, it can be suggested that retention force relates with tongue bulb size, ultimately with tongue volume. A further study needs to be performed in the patients with snoring and OSA.