• Archives of Plastic Surgery
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• v.34 no.5
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• pp.574-579
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• 2007

Purpose: The number of sore patients are increasing steadily, especially in old ages, chronic disease and paralytic patients. Most of patients need to surgical treatment. The aim of this paper is to assess clinical analysis of surgical treatment and to consider operative methods, complications, and recurrences.Methods: We reviewed the data from 82 consecutive patients with 101 pressure sores from March 2003 to May 2006 to discuss the occurrence rate and recurrence rate according to the site on the basis of the presence or absence of paraplegic and its etiology-the patients were categorized into three diagnostic groups: traumatic paraplegics(TP), nontraumatic paraplegics (NTP), and nontraumatic nonparaplegics(NTNP). We examined the sites and sizes of each lesions, patient's state, primary causes of pressure sore, operative methods as each sites and groups, occurrence of complications and recurrences on each groups. Results: In 82 patients, 52 patients were male, 30 patients were female. The male to female ratio was 1.7 :1. Mean age was 55.8 years. 27 patients were in TP group, 35 in NTP group, and 20 in NTNP group, respectively. The common site of sore were sacral area (50.5%), greater trochanteric area(15.8%) and ischial area(13.9%). In each group, incidence rate of recurrence and complication were 11.1%, 40.7% in TP, 5.7%, 5.7% in NTP and 15%, 45% in NTNP. Conclusion: Surgeons must consider the general condition of the patient and possibility of recurrence and returning of daily life. We propose that cutaneous flap, fasciocutaneous flap or skin graft as well as musculocutaneous flap be useful to repair of sore site as each patient's state.

• Steel and Composite Structures
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• v.9 no.5
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• pp.419-444
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• 2009

Flange and web local buckling in beam plastic hinge regions of steel moment frames can prevent beam-column connections from achieving adequate plastic rotations under earthquake-induced forces. Reducing the flange-web slenderness ratios (FSR/WSR) of beams is the most effective way in mitigating local member buckling as stipulated in the latest seismic design specifications. However, existing steel moment frame buildings with beams that lack the adequate slenderness ratios set forth for new buildings are vulnerable to local member buckling and thereby system-wise instability prior to reaching the required plastic rotation capacities specified for new buildings. This paper presents results from a research study investigating the cyclic behavior of steel I-beams modified by a welded haunch at the bottom flange and reinforced with glass fiber reinforced polymers at the plastic hinge region. Cantilever I-sections with a triangular haunch at the bottom flange and flange slenderness ratios higher then those stipulated in current design specifications were analyzed under reversed cyclic loading. Beam sections with different depth/width and flange/web slenderness ratios (FSR/WSR) were considered. The effect of GFRP thickness, width, and length on stabilizing plastic local buckling was investigated. The FEA results revealed that the contribution of GFRP strips to mitigation of local buckling increases with increasing depth/width ratio and decreasing FSR and WSR. Provided that the interfacial shear strength of the steel/GFRP bond surface is at least 15 MPa, GFRP reinforcement can enable deep beams with FSR of 8-9 and WSR below 55 to maintain plastic rotations in the order of 0.02 radians without experiencing any local buckling.

• Journal of KIISE:Computing Practices and Letters
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• v.12 no.3
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• pp.208-217
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• 2006

This paper presents a cloth simulation technique that implements plastic deformation. Plasticity is the property that material does not restore completely to the original state once deformed, in contrast to elasticity. We model cloth using a particle model, and posit two kinds of connections between particles, i.e. the sequential connections between immediate neighbors, and the interlaced connections between every other neighbors. The sequential connections represent the compression and tension of cloth, and the interlaced connections the bending in cloth. The sequential connections are modeled by elastic springs, and the interlaced connections by elastic or plastic spring depending on the amount of the current deformation of the connections. Our model is obtained by adding plastic springs to the existing elastic particle model of cloth. Using the new model, we have been able to simulate bending wrinkles, permanently deformed wrinkles, and small wrinkles widely distributed over cloth. When constructing elastic and plastic spring models for sequential and interlaced connections, we took pain to prevent the stiffness matrix of the whole cloth system from being indefinite, in order to help achieve physical stability of the cloth motion equation and to improve the effectiveness of the numerical method.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.7 s.166
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• pp.1112-1119
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• 1999

Fracture resistance(J-R) curves, which are used for the elastic-plastic fracture mechanics analyses, are known to be dependent on the cyclic loading history. The objective of this paper is to study the effect of reverse cyclic loading on J-R curves in CT specimens. The effect of two parameters was observed on the J-R curves during the reverse cyclic loading. One was the minimum-to-maximum load ratio(R) and the other was the incremental plastic displacement(${\delta}_{cycle}/{\delta}_i$), which is related to the amount of crack growth that occurs in a cycle. Fracture resistance test on CT specimens with varying load ratio and incremental plastic displacement were performed. For the SA 516 Gr. 70 steel, the results showed that the J-R curves were decreased with decreasing the load ratio and the incremental plastic displacement. When the load ratio was set to -1, the results of the J-R curves and the $J_i$ value were about $40{\sim}50$ percent of those for the monotonic loading condition. Also on condition that the incremental plastic displacement reached 1/40, the J-R curves and the $J_i$ value were about $50{\sim}60$ percent of those for the incremental plastic displacement of 1/10.

• Archives of Plastic Surgery
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• v.39 no.6
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• pp.601-605
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• 2012

Background Cryptotia is a congenital ear deformity in which the upper pole appears buried beneath the mastoid skin. Cryptotia is a common auricular malformation among Asians. The aim of this paper is to examine the surgical techniques for and complications of 34 cryptotic patients. Methods Surgery was performed for 34 cryptotic deformities (January 2005 to January 2012). Twenty-two patients (64.7%) were classified as having type I cryptotia, and 12 patients (37.5%) type II cryptotia. Among the type I cryptotia patients, 8 patients had mild deformity and 14 severe deformity. Among the type II cryptotia patients, 10 patients had mild deformity and 2 severe deformity. Results The mild deformities were corrected via Z-plasty, V-Y plasty, full-thickness skin graft, and transposition flap, while the severe deformities were corrected via cartilage graft or Medporfor the spread of cartilage adhesion of antihelix. There were two cases of reinvagination in the autologous cartilage graft group. Implant exposure occurred with Medpor (two cases). There were two cases of hypertrophic scar on the previous surgical wound with Medpor. There were no complications in the 18 patients who had mild deformities. Conclusions The type I cryptotia patients had more severe deformities than the type II cryptotia patients. As most of the type II cryptotia patients had only mild deformities, their deformities were corrected without using autologous conchal cartilage graft or Medpor, except for two patients. Through more case analyses, researchers should make an effort to identify methods for recurrence and prevention of complication.

• Archives of Plastic Surgery
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• v.43 no.5
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• pp.424-429
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• 2016

Background The objective of this paper was to describe a novel technique for improving the maintenance of nipple projection in primary nipple reconstruction by using acellular dermal matrix as a strut in one of three different configurations, according to the method of prior breast reconstruction. The struts were designed to best fill the different types of dead spaces in nipple reconstruction depending on the breast reconstruction method. Methods A total of 50 primary nipple reconstructions were performed between May 2012 and May 2015. The prior breast reconstruction methods were latissimus dorsi (LD) flap (28 cases), transverse rectus abdominis myocutaneous (TRAM) flap (10 cases), or tissue expander/implant (12 cases). The nipple reconstruction technique involved the use of local flaps, including the C-V flap or star flap. A $1{\times}2-cm$ acellular dermal matrix was placed into the core with O-, I-, and L-shaped struts for prior LD, TRAM, and expander/implant methods, respectively. The projection of the reconstructed nipple was measured at the time of surgery and at 3, 6, and 9 months postoperatively. Results The nine-month average maintenance of nipple projection was $73.0%{\pm}9.67%$ for the LD flap group using an O-strut, $72.0%{\pm}11.53%$ for the TRAM flap group using an I-strut, and $69.0%{\pm}10.82%$ for the tissue expander/implant group using an L-strut. There were no cases of infection, wound dehiscence, or flap necrosis. Conclusions The application of an acellular dermal matrix with a different kind of strut for each of 3 breast reconstruction methods is an effective addition to current techniques for improving the maintenance of long-term projection in primary nipple reconstruction.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.6 no.2
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• pp.111-120
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• 1986

Steel frame structures are widely used in construction because of their efficient strength and rigidity and considered proper cases for design and analysis using concept of plastic behavior. The purpose of plastic analysis is to determine the collapse load of a structure when the plastic moments of its members are given, and optimal plastic design is to compute the plastic moments of the members that minimize total structural weight. In this paper, the plastic analysis and optimal design are performed by using the static approach and solved by the simplex method. From the result of the analysis the solutions by this study show more efficiency in calculations. Also, the structural weight solved by the simplex method in case of two story frame is proved more economical than the one using the elastic design around 24%.

• Archives of Plastic Surgery
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• v.40 no.3
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• pp.226-231
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• 2013

Background The reconstruction of volar surface defects is difficult because of the special histologic nature of the tissue involved. The plantar surface is the most homologous in shape and function and could be considered the most ideal of reconstructive options in select cases of volar surface defects. In this paper, we evaluate a single institutional case series of volar tissue defects managed with second toe plantar free flaps. Methods A single-institution retrospective review was performed on 12 cases of reconstruction using a second toe plantar free flap. The mean age was 33 years (range, 9 to 54 years) with a male-to-female ratio of 5-to-1. The predominant mechanism was crush injury (8 cases) followed by amputations (3 cases) and a single case of burn injury. Half of the indications (6 cases) were for soft-tissue defects with the other half for scar contracture. Results All of the flaps survived through the follow-up period. Sensory recovery was related to the time interval between injury and reconstruction-with delayed operations portending worse outcomes. There were no postoperative complications in this series. Conclusions Flexion contracture is the key functional deficit of volar tissue defects. The second toe plantar free flap is the singular flap whose histology most closely matches those of the original volar tissue. In our experience, this flap is the superior reconstructive option within the specific indications dictated by the defect size and location.

• Archives of Plastic Surgery
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• v.47 no.2
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• pp.171-177
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• 2020

Background Infrabrow blepharoplasty has become a common surgical method used to rejuvenate aged upper eyelids in Asians. In this paper, we describe the parallel excision method for infrabrow blepharoplasty as a useful alternative to the conventional elliptical excision method. The authors' experience over a 3-year period is presented and reviewed. Methods A retrospective review of parallel excision infrabrow blepharoplasty cases at our hospital between 2014 and 2017 was performed. Three oculoplastic surgeons compared preoperative and postoperative photographs using the Strasser grading system. Results From the medical records of 123 patients, a total of 93 patients with moderate-to-severe bilateral dermatochalasis were selected as subjects. The exclusion criterion was levator function less than 8 mm. The total mean follow-up period was 2 years (range, 0.5-3.5 years). The mean skin excision height and width were 9.75 mm (range, 5-16 mm) and 58.51 mm (range, 42-75 mm), respectively. All patients who underwent surgery recovered without major complications, and all patients had high levels of satisfaction and improvements in their visual field. In the Strasser evaluation performed by the oculoplastic surgeons, most patients were found to have excellent results. Conclusions The parallel excision method for infrabrow blepharoplasty is a safe and effective technique that yields more natural- and youthful-looking eyelids than the conventional elliptical excision method. In our method, more effective manipulation of the orbicularis oculi muscle led to a reduction in frontalis compensation, resolution of sunken eyelids, and correction of lateral hooding.

• Journal of Navigation and Port Research
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• v.36 no.3
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• pp.181-187
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• 2012

Highly plastic clays in their normally consolidated states are not always linear but are concave downwards. Thus their compression index deceases with the increase of consolidation pressure. The $e-{\log}{\sigma}_{\upsilon}{\prime}$ curves of plastic or non-plastic silty clays are not linear but are convex upwards. In this paper, consolidation tests were conducted with several undisturbed field soils of Korea south coast and their $e-{\log}{\sigma}_{\upsilon}{\prime}$ plots are not always linear. In case of using Butterfield's method(liquid limit 50~100%), ${\ln}{\upsilon}-{\ln}{\sigma}_{\upsilon}{\prime}$ plots are linear. But some undisturbed samples which have void ratio over 2.24, liquid limit over 100% and plasticity index over 60% are not linear. In results of consolidation tests with remolded samples which contain silt(fly ash) contents of 90% has compression index increasing with the increase in consolidation pressure.