• Steel and Composite Structures
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• 제31권1호
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• pp.99-112
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• 2019

Semi-rigid joints have been widely studied in literature in recent decades because they affect greatly the structural response of frames. In literature, the behavior of semi-rigid joints is commonly assumed to be identical under positive and negative moments which are obviously incorrect in many cases where joint details such as bolt arrangement or placement of haunch are vertically asymmetrical. This paper evaluates two common types of steel frames with asymmetrical beam-to-column joints by Direct Analysis allowing for plasticity. A refined design method of steel frames using a proposed simple forth order curved-quartic element with an integrated joint model allowing for asymmetrical geometric joint properties is presented. Furthermore, the ultimate behavior of six types of asymmetrical end-plate connections under positive and negative moment is examined by the Finite Element Method (FEM). The FEM results are further applied to the proposed design method with the curved-quartic element for Direct Analysis of two types of steel frames under dominant gravity or wind load. The ultimate frame behavior under the two different scenarios are examined with respect to their failure modes and considerably different structural performances of the frames were observed when compared with the identical frames designed with the traditional method where symmetrical joints characteristics were assumed. The finding of this research contributes to the design of steel frames as their asymmetrical beam-to-column joints lead to different frame behavior when under positive and negative moment and this aspect should be incorporated in the design and analysis of steel frames. This consideration of asymmetrical joint behavior is recommended to be highlighted in future design codes.

• Imaging Science in Dentistry
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• 제49권2호
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• pp.159-169
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• 2019

Purpose: Cone-beam computed tomography (CBCT) is widely used for 3-dimensional assessments of cranio-maxillo-facial relationships, especially in patients undergoing orthognathic surgery. We have introduced, for reference in CBCT cephalometry, an anatomical mid-sagittal plane (MSP) identified by the nasion, the midpoint between the posterior clinoid processes of the sella turcica, and the basion. The MSP is an updated version of the median plane previously used at our institution for 2D posterior-anterior cephalometry. This study was conducted to test the accuracy of the CBCT measures compared to those obtained using standard posterior-anterior cephalometry. Materials and Methods: Two operators measured the inter-zygomatic distance on 15 CBCT scans using the MSP as a reference plane, and the CBCT measurements were compared with measurements made on patients' posterior-anterior cephalograms. The statistical analysis evaluated the absolute and percentage differences between the 3D and 2D measurements. Results: As demonstrated by the absolute mean difference (roughly 1 mm) and the percentage difference (less than 3%), the MSP showed good accuracy on CBCT compared to the 2D plane, especially for measurements of the left side. However, the CBCT measurements showed a high standard deviation, indicating major variability and low precision. Conclusion: The anatomical MSP can be used as a reliable reference plane for transverse measurements in 3D cephalometry in cases of symmetrical or asymmetrical malocclusion. In patients who suffer from distortions of the skull base, the identification of landmarks might be difficult and the MSP could be unreliable. Becoming familiar with the relevant software could reduce errors and improve reliability.

• Archives of Plastic Surgery
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• 제46권1호
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• pp.16-22
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• 2019

Background Various surgical techniques have been used to correct Tessier number 7 craniofacial cleft, which involves macrostomia, ear deformity, and hemifacial microsomia. To achieve symmetrical and satisfactory results in patients with macrostomia, the authors performed a 1-mm medial overcorrection on the cleft side and evaluated the results of this procedure. Methods A retrospective medical record review of patients diagnosed with Tessier number 7 craniofacial cleft from March 1999 to February 2017 was performed. Using clinical photographs, outpatient clinic records, and operative records, information was recorded regarding concurrent congenital anomalies, postoperative complications, and follow-up. Using Photoshop CS2, the length of both sides of the lip was compared. The ratio of these lengths was calculated to evaluate lip symmetry. Results Of the patients treated at the Department of Plastic and Reconstructive Surgery at Kyungpook National University Chilgok Hospital, 11 (male-to-female sex ratio, 7:4) were diagnosed with Tessier number 7 craniofacial cleft. Concurrent congenital anomalies included skin tag, hemifacial microsomia, and cleft palate. The mean duration of follow-up was $78.273{\pm}72.219$ months and the mean ratio of the lengths of both sides of the lip was $1.048{\pm}0.071$. Scar widening occurred as a postoperative complication in some patients. No cases of wound infection, bleeding, or wound dehiscence occurred. Conclusions For the successful correction of macrostomia, plastic surgeons should consider both functional and aesthetic problems of the lip. Adequate repair of the orbicularis oris muscle, skin closure with Z-plasty, and medial overcorrection of the neo-oral commissure led to good results in our patients.

• 패션비즈니스
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• 제23권2호
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• pp.18-33
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• 2019

The purpose of this study is to develop fashion cultural products that contain an example of cultural symbolism, which is based on the results of iconological analysis seen on imaginary animals. The method of research was to derive design ideas through a verbal association method, using the technique of mind map as based on the iconological analysis results. In the scarf design, four auspicious animals were used as the main motifs, and the background elements that appeared with each folk painting were used as sub-motifs for each of the four animals. In this case, the Yong was expressed with an image of clouds and flames as sub-motifs, and was strongly represented by the presence of a contrast color combination. In what follows, the Bonghwang was used with the sun and feathers in a stable structure due to its four-way arrangement, and was expressed with its soft light tone. The Shingoo was used with blue and khaki colors of dull and deep tone, and the image of aquatic plants and lotus were used. Finally, with the Kirin was represented by a symmetrical structure as characterized with a dull toned color and square border that provides a sense of stability. The clutch bags were as generally expressed using simple animal motifs, and were composed of a uniform motif and color. The design process used the Illustrator CS6 to perform motifs design. In the end, the process finally developed the actual product of eight scarves and four clutch handbags.

• 국제강구조저널
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• 제18권4호
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• pp.1440-1463
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• 2018

The Wagner coefficient is a key parameter used to describe the inelastic lateral-torsional buckling (LTB) behaviour of the I-beam, since even for a doubly-symmetric I-section with residual stress, it becomes a monosymmetric I-section due to the characteristics of the non-symmetrical distribution of plastic regions. However, so far no theoretical derivation on the energy equation and Wagner's coefficient have been presented due to the limitation of Vlasov's buckling theory. In order to simplify the nonlinear analysis and calculation, this paper presents a simplified mechanical model and an analytical solution for doubly-symmetric I-beams under pure bending, in which residual stresses and yielding are taken into account. According to the plate-beam theory proposed by the lead author, the energy equation for the inelastic LTB of an I-beam is derived in detail, using only the Euler-Bernoulli beam model and the Kirchhoff-plate model. In this derivation, the concept of the instantaneous shear centre is used and its position can be determined naturally by the condition that the coefficient of the cross-term in the strain energy should be zero; formulae for both the critical moment and the corresponding critical beam length are proposed based upon the analytical buckling equation. An analytical formula of the Wagner coefficient is obtained and the validity of Wagner hypothesis is reconfirmed. Finally, the accuracy of the analytical solution is verified by a FEM solution based upon a bi-modulus model of I-beams. It is found that the critical moments given by the analytical solution almost is identical to those given by Trahair's formulae, and hence the analytical solution can be used as a benchmark to verify the results obtained by other numerical algorithms for inelastic LTB behaviour.

• Design & Manufacturing
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• 제13권3호
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• pp.12-18
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• 2019

Fluid jet polishing is a method of jetting a fluid to polish a concave or free-form surface. However, the fluid jet method is difficult to form a stable polishing spot because of the lack of concentration. In order to solve this problem, MR fluid jet polishing system using an abrasive mixed with an MR fluid whose viscosity changes according to the intensity of a magnetic field is under study. MR fluid jet polishing is not easy to formulate for precise optimal conditions and material removal due to numerous fluid compositions and process conditions. Therefore, in this paper, quantitative data on the factors that have significant influence on the machining conditions are presented using various simulations and the correlation studies are conducted. In order to verify applicability of the fabricated MR fluid jet polishing system by nozzle diameter, the flow pattern and velocity distribution of MR fluid and polishing slurry of MR fluid jet polishing were analyzed by flow analysis and shear stress due to magnetic field changes was analyzed. The MR fluid of the MR fluid jet polishing and the flow pattern and velocity distribution of the polishing slurry were analyzed according to the nozzle diameter and the effects of nozzle diameter on the polishing effect were discussed. The analysis showed that the maximum shear stress was 0.45 mm at the diameter of 0.5 mm, 0.73 mm at 1.0 mm, and 1.24 mm at 1.5 mm. The cross-sectional shape is symmetrical and smooth W-shape is generated, which is consistent with typical fluid spray polishing result. Therefore, it was confirmed that the high-quality surface polishing process can be stably performed using the developed system.

• 대한건축학회논문집:구조계
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• 제34권4호
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• pp.51-58
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• 2018

Various types of pilotis frames are used on the ground level of high-rise buildings. In some cases, their interior finishing is destroyed by strong winds or typhoons. In the case of a corner pilotis, the peak wind pressure coefficients were greater on the ceiling than they were on the wall for all wind angles. Specifically, on the ceiling portion of a pilotis, the coefficient increased gradually from the outside to the inside in a symmetrical form that centered on the corner edge. However, the minimum peak wind pressure coefficient was greater at the center of the ceiling than it was on the edge of the pilotis' interior. Additionally, the higher the height of the pilotis, the greater the peak wind pressure coefficient was due to the turbulent flow that occurs within a pilotis. In this study, we evaluated peak wind pressures to design an interior finishing for the end edge of a pilotis and for corner piloti. In terms of specific wind angles, the maximum and minimum peak wind pressure coefficients were each observed. They were a maximum of $320^{\circ}$ and a minimum of $270^{\circ}$ for corner piloti and $0^{\circ}$ and $270^{\circ}$, respectively, for the end edge piloti.

• 건축역사연구
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• 제29권6호
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• pp.79-88
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• 2020

During the Joseon Dynasty, the rituals that were celebrated in the palaces were mainly held inside the palace and in the courtyard of the palace. Mats were spread on the floor of the place where the ritual was held. The mats spread in the Joseon Dynasty rituals divided the space in various ways, and in particular, they were spread in a certain form in the spaces of royal wedding, customs, and court banquet. Mats were the primary physical element that divided the royal ritual space of the Joseon Dynasty, and functioned to elevate the general space to the ritual space. In the ritual space, mats were spread inside the palace, and divided the courtyard of the palace into left and right in a symmetrical form to distinguish the hierarchy of the participants. Mats with special and white patterns were spread in the external ceremonial space and mats with flower and colorful patterns were spread in the internal ceremonial space. This was the subdivision of the Confucianism's male-female division through the mat. The pattern of the mat that divided the space of the royal family elders also meant longevity to reflect the filial thoughts of the Confucianism through the mat. Mats were a physical element for subdividing the royal family and the participants in the hierarchy of the space where the ritual is held, and it also performed a subdividing function between the royal participants. In other words, in the Joseon Dynasty ritual space, mats were temporarily spread while the ritual is being celebrated and functioned to elevate the space to a ritual space. It is confirmed that the fact that the mats were temporarily spread to divide the space into the hierarchies according to the status and were subdivided into colors and patterns to perform the function to reflect the subdivision of the royal family according to Confucianism and the statue of filial piety in the ritual.

• PNF and Movement
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• 제12권1호
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• pp.19-25
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• 2014

Purpose: To investigate the effect of action observation training on the muscle onset time and symmetrical use of rectus femoris(RF) and gastrocnemius medialis(GCM) during sit-to-stand (STS). Methods: Sixteen patients with stroke entered a single-blind trial and were randomly assigned to the experimental(Action) or control(Landscape) groups. Those in the Action observation group watched video clips showing specific movement and strategies to STS, wheas those in the control group watched video clips of static pictures showing differnet landscapes. All patients was measured the EMG data in the STS on the affected side and unaffected side. The EMG data were collected from RF and GCM while performing the STS task. The EMG onset time and onset time ratio for the RF and GCM were calculated by dividing the EMG onset time of RF and GCM action on the affected side by these on the unaffected side. Results: Onset time of affected side RF, GCM was significantly faster action observation training group than control group(p<.05). But interventions before and after the symmetry did not show a significant increase. Conclusion: There findings suggest that action observation training has a positive effect on the muscle onset time shortened during STS tasks.

• Journal of Periodontal and Implant Science
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• 제51권2호
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• pp.77-87
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• 2021

Purpose: The aim of this study was to compare the efficacy of the tunnel technique for root coverage using a new xenogeneic acellular dermal matrix vs. connective tissue grafting (CTG) for the treatment of multiple maxillary adjacent recessions (recession type 1) at 12 months postoperatively. Methods: This study enrolled 12 patients with at least 3 contiguous, bilateral, symmetrical maxillary gingival recessions (i.e., at least 6 recessions per patient). In total, 74 recessions were treated using the modified coronally advanced tunnel (MCAT) technique combined with a novel porcine-derived acellular dermal matrix (PADM) at 37 test sites or CTG at 37 control sites. The following clinical parameters were measured: recession height, clinical attachment level, width of keratinized tissue, probing depth, recession width, gingival thickness, mean root coverage (MRC), and complete root coverage (CRC). Comparisons between test and control groups were made for pain visual analog scale scores at 14 days. Results: At 12 months, the MCAT with PADM (test) yielded a statistically significant improvement in all clinical parameters studied. MRC was significantly higher on the control sides (80.6%±23.7%) than on the test sides (68.8%±23.4%). Similarly, CRC was 48.7%±6.8% on the control sides (CTG), in contrast to 24.3%±8.2% on the test sides (PADM). Statistically significant differences were observed in favor of the control sides for all clinical parameters studied. Nevertheless, the MCAT in adjunction with PADM was clearly superior at reducing mean and maximum patient-reported postoperative pain intensity and pain duration in the first week after surgery. Conclusions: The use of PADM to treat multiple recessions improved clinical parameters at 12 months, but these outcomes were nevertheless poorer than those observed for CTG. However, PADM reduced morbidity, particularly the pain experienced by patients.