• Journal of the Korean Institute of Rural Architecture
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• v.21 no.3
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• pp.25-32
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• 2019

This study is to derive the types of displacement and damage that occur in wooden architecture cultural assets. Although the wooden architectural cultural assets are being repaired through continuous maintenance, secondary problems frequently occur. This is because the root cause of the problem has yet to be solved. The types of displacement and damage that occur in the wooden architecture cultural asset are classified into three parts: the foundation section, the gagu section, and the roof section. In turn, the three main factors that lead to displacement and damages are the structures' load impact, the durability deterioration, and the imbalance. Load impact is a phenomenon in which the member is subjected to a load that causes deformation or cracks. Durability decline is a natural phenomenon that reduces the performance of lumber as a result of check shake, termite damage, and decay. The imbalance is a condition in which the lumber is twisted and the force balance is lost, due to either drying shrinkage or displacement of the gagu section.

• The Journal of Advanced Prosthodontics
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• v.10 no.5
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• pp.388-394
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• 2018

PURPOSE. To measure axial displacement of different implant-abutment connection types and materials during screw tightening at the recommended torque by using a contact scanner for two-dimensional (2D) and three-dimensional (3D) analyses. MATERIALS AND METHODS. Twenty models of missing mandibular left second premolars were 3D-printed and implant fixtures were placed at the same position by using a surgical guide. External and internal fixtures were used. Three implant-abutment internal connection (INT) types and one implant-abutment external connection (EXT) type were prepared. Two of the INT types used titanium abutment and zirconia abutment; the other INT type was a customized abutment, fabricated by using a computer-controlled milling machine. The EXT type used titanium abutment. Screws were tightened at $10N{\cdot}cm$, simulating hand tightening, and then at the manufacturers' recommended torque ($30N{\cdot}cm$) 10 min later. Abutments and adjacent teeth were subsequently scanned with a contact scanner for 2D and 3D analyses using a 3D inspection software. RESULTS. Significant differences were observed in axial displacement according to the type of implant-abutment connection (P<.001). Vertical displacement of abutments was greater than overall displacement, and significant differences in vertical and overall displacement were observed among the four connection types (P<.05). CONCLUSION. Displacement according to connection type and material should be considered in choosing an implant abutment. When adjusting a prosthesis, tightening the screw at the manufacturers' recommended torque is advisable, rather than the level of hand tightening.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1998.10a
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• pp.3-8
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• 1998

The industrial revolution in England was based on the manufacturing systems by the power of water mill and rapidly progressed by the innovation of steam engine. It is no exaggeration to say that today's civilization is realized by the development of various types of power machinery, namely fluid machinery and heat engine. The electric energy is converted mainly from thermal energy (mainly steam) of mineral oil, coal and nuclear fuel through generator connected with steam turbine which is a kind of power machinery. There are various types of power machinery as shown in Tables 1a and 1b. They are classified into two types by use. One is absorption type of fluid and/or thermal energy, for examples, windmill and heat engine. The other is provision type of the energies for examples, pump, compressor and propulsion. By flow type, they are also classified by two types, turbo type and positive-displacement type. The turbo type began from water mill and windmill and evolve to steam turbine and finally to gas turbine. The positive-displacement type started from reciprocating water pump and developed into steam engine and changed to reciprocating combustion engine. The pumps and motors used in oil hydraulic system for power control are also positive-displacement type.

• Journal of Oral Medicine and Pain
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• v.25 no.1
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• pp.73-85
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• 2000

The purposes of the study were (1) to see if there are various types of disc configuration in normal temporomandibular joint and, if so, (2) to examine whether a specific type of disc configuration is susceptible to disc displacement, and (3) to see if a specific type of disc configuration and position is related to early relief of clinical symptoms from the anterior disc displacement without reduction to conservative treatment. From the magnetic resonance (MR) images taken for the patients with symptoms of temporomandibular disorders, 235 images as normal joint group, 255 images as anterior disc displacement with reduction group, and 249 images as anterior disc displacement without reduction group were selected, After the TMJ image was scanned and processed with Photoshop program, the disc configuration was determined, The incidence of various types of disc configuration was analyzed according to age, sex, diagnostic group, and the promptness of symptom relief. The disc position was also examined in relation to the promptness of symptom relief. The results were as follows : 1. In the normal joint group, biconcave type appeared most frequently and reversed, biplanar type in order, Posterior band enlarged and folded type didn't appear at all. On the other hand, in the anterior disc displacement without reduction group, folded type appeared most frequently and also posterior band enlarged type were found often. 2. There were statistically significant differences between sex and configuration of disc in the normal joint group and no statistically significant differences in the anterior disc displacement with reduction group and anterior disc displacement without reduction group, 3. There were no statistically significant differences between age and configuration of disc in the normal, anterior disc displacement with reduction group and anterior disc displacement without reduction group. 4. In anterior disc displacement without reduction group, rapid response was observed in biconcave and reversed type and delayed response was observed in folded type.

• Imaging Science in Dentistry
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• v.31 no.3
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• pp.145-151
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• 2001

Purpose : To investigate the hypothesis that the morphology of the articular eminence of the temporomandibular joint is a predisposing factor for disc displacement. Materials and Methods: MR images of 126 temporomandibular joints in 94 patients were analyzed to assess for morphology of the articular eminence and disc displacement. The displaced disc was further categorized as disc displacement with reduction (DDWR) and disc displacement without reduction (DDWOR). The morphology of the articular eminence was classified into four types; box, sigmoid, flattened, and deformed. The relationship between the four types of shape of the articular eminence and the two types of disc position was assessed. Results: In the DDWR and DDWOR groups, the morphology of articular eminence were a box type in 40.5%, a sigmoid type in 30.2%, a flattened type in 24.6%, and a deformed type in 4.7%. The box type of the articular eminence were 34.3% in the DDWR group and 42.9% in the DDWOR group. The sigmoid type of the articular eminence were 34.3% in the DDWR group and 28.6% in the DDWOR group. The flattened type of the articular eminence were 28.6% in the DDWR group and 23.1 % in the DDWOR group. The deformed type of articular eminence were 2.9% in the DDWR group and 5.5% in the DDWOR group. Conclusion: Disc displacement is more likely to be found in the temporomandibular joints with a box-shaped articular eminence. It can be considered that shape of the articular eminence is related to the development of disc displacement.

• The korean journal of orthodontics
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• v.44 no.6
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• pp.312-319
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• 2014

Objective: Facial-type-associated variations in diagnostic features have several implications in orthodontics. For example, in hyperdivergent craniofacial types, growth imbalances are compensated by displacement of the condyle. When diagnosis and treatment planning involves centric relation (CR), detailed knowledge of the condylar position is desirable. The present study aimed to measure condylar displacement (CD) between CR and maximum intercuspation in three facial types of an asymptomatic orthodontic population. Methods: The study was conducted in 108 patients classified into three groups of 36 individuals each (27 women and 9 men; mean age, 20.5 years), based on the following facial patterns: hyperdivergent, hypodivergent, and intermediate. To quantify CD along the horizontal and vertical axes, the condylar position was analyzed using mounted casts on a semi-adjustable articulator and a mandibular position indicator. The Student t-test was used to compare CD between the groups. Results: Vertical displacement was found to be significantly different between the hyperdivergent and hypodivergent groups (p < 0.0002) and between the hyperdivergent and intermediate groups (p < 0.0006). The differences in horizontal displacement were not significant between the groups. In each group, vertical CD was more evident than horizontal displacement was. Conclusions: All facial types, especially the hyperdivergent type, carried a significantly high risk of CD. Therefore, the possibility of CD should be carefully evaluated and considered in the assessment of all orthodontic cases in order to accurately assess jaw relationships and avoid possible misdiagnosis.

• Smart Structures and Systems
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• v.14 no.4
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• pp.699-718
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• 2014

The indirect displacement estimation using acceleration and strain (IDEAS) method is extended to various types of beam structures beyond the previous validation on the prismatic or near-prismatic beams. By fusing different types of responses, the IDEAS method is able to estimate displacements containing pseudo-static components with high frequency noise to be significantly reduced. However, the concerns to the IDEAS method come from possible disagreement of the assumed sinusoidal mode shapes to the actual mode shapes, which allows the IDEAS method to be valid only for simply-supported prismatic beams and limits its applicability to real world problems. In this paper, the extension of the IDEAS method to the general types of beams is investigated by the mathematical formulation of the modal mapping matrix only for the monitored substructure, so-called monitoring span. The formulation particularly considers continuous and wide beams to extend the IDEAS method to general beam structures that reflect many real bridges. Numerical simulations using four types of beams with various irregularities are presented to show the effectiveness and accuracy of the IDEAS method in estimating displacements.

• International Journal of Concrete Structures and Materials
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• v.7 no.2
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• pp.135-153
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• 2013

This study investigates the direct displacement based design (DDBD) approach for different types of reinforced concrete structural systems including single moment-resisting, dual wall-frame and dual steel-braced systems. In this methodology, the displacement profile is calculated and the equivalent single degree of freedom system is then modeled considering the damping characteristics of each member. Having calculated the effective period and secant stiffness of the structure, the base shear is obtained, based on which the design process can be carried out. For each system three frames are designed using DDBD approach. The frames are then analyzed using nonlinear time-history analysis with 7 earthquake accelerograms and the damage index is investigated through lateral drift profile of the models. Results of the analyses and comparison of the nonlinear time-history analysis results indicate efficiency of the DDBD approach for different reinforced concrete structural systems.

• Smart Structures and Systems
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• v.15 no.3
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• pp.645-663
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• 2015

Recently, an indirect displacement estimation method using data fusion of acceleration and strain (i.e., acceleration-strain-based method) has been developed. Though the method showed good performance on beam-like structures, it has inherent limitation in applying to more general types of bridges that may have complex shapes, because it uses assumed analytical (sinusoidal) mode shapes to map the measured strain into displacement. This paper proposes an improved displacement estimation method that can be applied to more general types of bridges by building the mapping using the finite element model of the structure rather than using the assumed sinusoidal mode shapes. The performance of the proposed method is evaluated by numerical simulations on a deck arch bridge model and a three-span truss bridge model whose mode shapes are difficult to express as analytical functions. The displacements are estimated by acceleration-based method, strain-based method, acceleration-strain-based method, and the improved method. Then the results are compared with the exact displacement. An experimental validation is also carried out on a prestressed concrete girder bridge. The proposed method is found to provide the best estimate for dynamic displacements in the comparison, showing good agreement with the measurements as well.

• The Journal of the Korean dental association
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• v.58 no.6
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• pp.364-376
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• 2020

Internal derangement of the temporomandibular joint (TMJ) is condition in which articular disc has become displaced from its normal functional relationship with the mandibular condyle and the articular portion of the temporal bone. Common types of internal derangement include disc displacement with reduction (with or without intermittent locking), and disc displacement without reduction (with or without limited opening) classified according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Treatment varies depending on diagnosis. Therefore, differential diagnosis should be made for appropriate treatment.