• Imaging Science in Dentistry
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• v.50 no.2
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• pp.125-132
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• 2020

Purpose: The positions of the mandibular foramen (MnF) and the lingula affect the success rate of inferior alveolar nerve block. The objective of this study was to investigate aspects of the MnF and the lingula relevant for mandibular block anesthesia using cone-beam computed tomography (CBCT). Materials and Methods: Fifty CBCT scans were collected from a picture archiving and communications system. All scans were taken using an Alphard Vega 3030 (Asahi Roentgen Co. Ltd., Kyoto, Japan). Fifty-eight MnFs of 30 subjects were included in the study. The position of the MnF, the size of the MnF, the position of the lingula, the size of the lingula, and the shape of the lingula were measured and recorded. All data were statistically analyzed at a significance level of P<0.05. Results: The position of MnF was 0.1 mm and 0.8 mm below the occlusal plane in males and females, respectively. The horizontal position of the MnF was slightly anterior to the center of the ramus in males and in the center in females (P<0.05). The vertical position of the MnF was lower in females than in males(P<0.05). The MnF was an oval shape with a longer anteroposterior dimension. The height of the lingula was 9.3 mm in males and 8.2 mm in females. The nodular type was the most common shape of the lingula, followed by the triangular, truncated, and assimilated types. Conclusion: CBCT provided useful information about the MnF and lingula. This information could improve the success rate of mandibular blocks.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.2
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• pp.131-138
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• 2015

In this paper, the modified live-load and designed formula are studied according to the fact the highway bridge design specifications are recently revised. The two examples for composite steel plates and PSC girder bridges are studied. The envelope is analyzed with the finite element models and lateral load distribution method applying the existing highway bridge specification(2010), the newly revised highway bridge specification(2015) and AASHTO LRFD. In case of composite steel plates, length changes between spans are studied, and in case of PSC girder. changes of the number of cross-beams and spans, and span-lengths, are analyzed.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.11
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• pp.31-37
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• 1998

Magnitude/phase controlling circuit which is composed of attenuator and phase shifter make phase/gain cross-coupling, so too much tuning time is needed to find optimum operation point. In this paper, vector attenuator which control magnitude and phase of input signals is proposed. Vector attenuator in past ignores phase variation characteristics of attenuator, but vector attenuator of this paper compensates phase variation characteristics of attenuator. This vector attenuator consists of 0$^{\circ}$/180$^{\circ}$ phase shifter and low phase shifting attenuator and so forth. A 0$^{\circ}$/180$^{\circ}$ phase shifter has 0$^{\circ}$/179.9$^{\circ}$ phase shifting characteristics at a center frequency 881 MHz and a low phase shifting attenuator has an attenuation of 25dB, within the limit of 3.6$^{\circ}$ phase shift and less than -20dB reflection characteristics at both input and output ports. The designed vector attenuator shows that cartesian coordinate plane of output signal space can be represented correctly.

• The korean journal of orthodontics
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• v.46 no.4
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• pp.199-211
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• 2016

Objective: Given the considerable disagreement between the Peer Assessment Rating (PAR) index and the American Board of Orthodontics Cast-Radiograph Evaluation, we aimed to develop a novel assessment system-the Improvement and Completion of Outcome (ICO) index-to evaluate the outcome of orthodontic treatment. Methods: Sixteen criteria from 4 major categories were established to represent the pretreatment malocclusion status, as well as the degree of improvement and level of completion of outcome during/after treatment: dental relationship (arch length discrepancy, irregularity, U1-SN, and IMPA); anteroposterior relationship (overjet, right and left molar position, ANB); vertical relationship (anterior overbite, anterior open-bite, lateral open-bite, SN-MP); and transverse relationship (dental midline discrepancy, chin point deviation, posterior cross-bite, occlusal plane cant). The score for each criterion was defined from 0 or -1 (worst) to 5 (ideal value or normal occlusion) in gradations of 1. The sum of the scores in each category indicates the area and extent of the problems. Improvement and completion percentages were estimated based on the pre- and post-treatment total scores and the maximum total score. If the completion percentage exceeded 80%, treatment outcome was considered successful. Results: Two cases, Class I malocclusion and skeletal Class III malocclusion, are presented to represent the assessment procedure using the ICO index. The difference in the level of improvement and completion of treatment outcome can be clearly explained by using 2 percentage values. Conclusions: Thus, the ICO index enables the evaluation of the quality of orthodontic treatment objectively and consecutively throughout the entire treatment process.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.3
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• pp.768-776
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• 1994

This paper describes computer-aided forging design for rib/web shaped parts. In manufacturing a part by means of forging process, the first step is to design the forging. This is done by modifying the given machined part geometry according to the requirements of the forging process. Traditionally, this is done by experienced forging designers using empirical forging design guidelines. Generally, it would be neither possible nor practical to develop a system which encompasses the design of all types of forgings. Accordingly, forging design can be simplified by considering critical two dimensional cross sections of the machined part geometry. This system is composed of three modules(process variable decision module, forging design module and redesign module) and each module is carried out in regular sequence. In the process variable decision module, first of all, the undercut is checked and modified, and then deep recesses and holes difficult to forge are eliminated. Also parting line, forging plane, forging plan view area, forging weight and maximum size(maximum height or width)are determined. In the forging design module, the magnitude of various allowances, draft angle, minimum web thickness, corner and fillet radius are determined and then geometry modification is performed. Finally, since the design rules and databases used in this system are based on parameters of the forging geometry, such as the trimmed forging plan area, forging weight, forging maxmum size, plausible estimates need to be made for these parameters. Therefore, in the re-design module, the design process is iterated until a satisfactory forging is obtained.

• Journal of Fashion Business
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• v.10 no.5
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• pp.159-179
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• 2006

This research checked about the necessity for the development of men's dress forms in the first investigation for the educational circle and the men's wear industry. Somatotype characteristics were analyzed in the second investigation of body measurement with the subjects of 200 male adults in their twenties residing in Busan. The following are the results of the present research to develop male dress forms for patternmaking: 1. In the group analysis for the characterization of front body types, three somatotypes were found and named H, Semi X, and Y. In the cluster analysis of side body types, four types were identified: D, I, d, and q. In the combination of front and lateral body types, four kinds were chosen: semi X-I, semi X-q, semi Y-I, and Y-q. 2. Through the comparison of plane figures by the plaster method as well as horizontal and vertical cross sections by the sliding gauge method, semi X-I was finally chosen as the standard somatotype for male dress form development. 3. Compared with the sliding gauge method of the present dress forms, the research dress form reflected better the shapes of the parts of the back and hips and the position of the waist, especially for males in their 20's. In addition, the dress form in the current research had superior points in all the items of clothing evaluation. Based on the above results, the sizes and models of the men's dress forms for patternmaking were developed.

• Journal of Biosystems Engineering
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• v.2 no.1
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• pp.33-48
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• 1977

Transporting agricultural products and the other material by the two-wheel-tractor (power-tiler)and trailer system may be one of its most widely used farming functions.The safety and hitching load for all the previaling performing conditions may be the general concern over the operation of the tiller-trailer system. In this study, a mathematical model to determine the static and dynamic forces excerting on the hitch point were developed . Based on the analysis of the model and the field measurements. the limiting hitching load and critical slope were analyzed. The results of the study are summarized as follows ; 1) The limit angle of slope land for the safety steering that two-wheel tractor-single axle trailer system was able to transport agricultural products was the direct angle (${\gamma}$) = 8 ; the cross angle$\beta$) 15 ; and it was decreased in accordance with the increase of carrying load ($W_4). 2) The critical velocity for safe operation in case of running on downward hill road was about 1.08m/sec. 3) The limiting carrying load for the safe steering was W$_4$=600kg. The degree of the safe steering for different braking methods was given in order as follows ; Simulataneous braking the tractor and trailer , braking the trailer only, and braking tractor only. 4) Among the three components of impact loads excerting on the hitch point, the component in the lateral direction ($P_{Vy}$) was near zero in spite of increase of hitching load ($W_4) , while the components in the other two mutually perpedicular directions ($P_{Vx}$ and ($P_{Vz}$) ) had larger values in horizontal plane than those in the slope lands. 5) Moment of forces on the lateral direction (M$y$) had the largest value among the three components of impact moment acting on the hitch point, however all the components were sharply increased in accordance with the increase of hitching loads ($W_4. Three components of the moment were the negative values.

• Journal of the Korean Society of Safety
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• v.20 no.2 s.70
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• pp.26-31
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• 2005

The strong continuous fiber reinforced metal matrix composites (MMCs) are recently used in aerospace and transportation applications as an advanced material due to its high strength and light weight. Unidirectional fiber-metal matrix composites have superior mechanical properties along the longitudinal direction. However, the applicability of continuous fiber reinforced MMCs is somewhat limited due to their relatively poor transverse properties. Therefore, the transverse properties of MMCs are significantly influenced by the properties of the fiber/matrix interface. In order to be able to utilize these MMCs effectively and with safety, it must be determined their elastic plastic behaviors at the interface. In this study, the interfacial stress states of transversely loaded unidirectional fiber reinforced metal matrix composites investigated by using elastic-plastic finite element analysis. Different fiber volume fractions $(5-60\%)$ were studied numerically. The interlace was treated as three thin layer (with different properties) with a finite thickness between the fiber and the matrix. The fiber is modeled as transversely isotropic linear-elastic, and the matrix as isotropic elastic-plastic material. Using proposed model, the effects of the interface region and fiber arrangement in MMCs on the distributions of stress and strain are evaluated. The stress distributions of a thin multi layer interface have much less changes compared with conventional perfect interface. The analyses were based on a two-dimensional generalized plane strain model of a cross-section of an unidirectional composite by the ANSYS finite element analysis code.

• Journal of Korean Society of Steel Construction
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• v.18 no.3
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• pp.349-359
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• 2006

This paper presents a new block stiffness matrix for the analysis an orthogonal Cartesian coordinate system. The displacement fields are defined using the first order shear deformable beam theory. The longitudinal displacement can be expressed as the sum of the projected plane deformation of the cross-section due to Timoshenko's beam theory and axial warping deformation due to modified Vlasov's thin-waled beam theory. The derived element takes into account flexural shear deformation and torsional warping deformation. Three different types of beam elements, namely, the two-noded, three-noded, and four-noded beam elements, are developed. The quadratic and cubic elements are found to be very efficient for the flexural analysis of laminated composite beams. The versatility and accuracy of the new element are demonstrated by comparing the numerical results available in the literature.

• Journal of Electrical Engineering and Technology
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• v.10 no.5
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• pp.2205-2210
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• 2015

Experimental studies have been carried out to study the principle operation of the conductive type wire-mesh tomography sensor and analyse the wire-mesh tomography sensor for the liquid/gas two-phase flow interface and void fraction distribution in a process column. The measurement of the two-phase flows in the process column is based on the cross-sectional local instantaneous conductivity. The sensor consists of two planes of parallel electrode wires with 16 electrodes each and was placed orthogonally with each plane. The sensor electrode wires were made of tinned copper wire with an outer diameter of 0.91 mm which stretched over the sensor fixture. Therefore, this result in the mesh grid size with 5.53×5.53mm². The wire-mesh sensor was tested in a horizontal liquid/gas two-phase flows process column with nominal diameter of 95.6 mm and the sampling frequency of 5882.3529 Hz. The tomogram results show that the wire-mesh tomography provides significant results to represent the void fraction distribution in the process column and estimation error was found in the liquid/gas interface level