• International conference on construction engineering and project management
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• 2007.03a
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• pp.721-728
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• 2007

The prediction of quality characteristics during the design phase of a construction project was fragmented, because no particular method exists. One of the most important key responses is the total displacements (horizontal and vertical). A brainstorming session produces the quality parameters i.e. the control factors which here are identified as: the steel joint, the pile's length, the excavation depth and angle, the distance between the piles, the anchor stretch and length to name just some of the most engaging in the design. The purpose of this study is to optimise these parameters to minimize the total displacements following a methodology based on Taguchi method. For this reason, a 2-level, L₈ orthogonal array has been employed to organize the experimentation. Data is obtained from a real-life excavation project designed on the Plaxis v.8 CAE package. Taguchi analysis is performed in the statistical package Minitab.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.38-39
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• 2021

The use of temporary container classrooms has increased in recent years due to the development of the construction industry and renovation or rehabilitation of schools. Therefore, various problems, such as errors during assembling, design and insulation issues, and noise problems, have surfaced during the construction of temporary container classrooms. This study analyzes the causes of assembly errors during the manufacturing and installation processes to improve the quality of temporary container classrooms. Assembly errors are caused by non-level planes and inaccurate cutting during the manufacturing process. In the installation process, poor leveling is a major factor that causes errors during the assembly of temporary container classrooms. These causes result in uneven horizontal or vertical planes and uneven height. To solve these problems, quality improvement measures, such as pin connection, jig, joint coupling, and surface plates are proposed in this study.

• The Journal of Korean Academy of Prosthodontics
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• v.24 no.1
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• pp.17-26
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• 1986

The purpose of this study was to investigate true hinge axis location with different times (8:00-9:00 A.M.,2:00-3:00 P.M.) and with experienced and inexperienced groups. 25 subjects, 23-27 years of age , with functionally acceptable occlusion, and no clinical signs of temporomandibular joint dysfunction were participated in this study. In this study arbitrary hinge axis point was located 13 mm anterior to the posterior margin of the tragus on a line from the center of the tragus to the outer canthus of the eye and then the true hinge axis point was located with T.M.J. hinge axis locator. The discrepancies of distance and the direction between true hinge axis point and arbitrary hinge axis point were studied according to times and two groups. The results obtained were as follows : 1. The mean distance from arbitrary hinge axis point to the true hinge axis point on the right and left sides was as follows : Experienced group: linear distance: $1.228{\pm}3.145mm$, vertical distance: $-1.128{\pm}2.515mm$, horizontal distance: $-0.484{\pm}1.806mm$. Inexperience group: linear distance: $1.628{\pm}3.158mm$, vertical distance: $-1.169{\pm}2.090mm$, horizontal distance: $-1.133{\pm}2.367mm$. Horizontal distance between experienced and inexperienced groups was significant statistically. (P<0.1) 2. True hinge axis points located within 5 mm of arbitrary hinge axis point were 86.7% in the experienced group and 84% in the inexperienced group. 3. For experienced operator A with time, the mean distance from arbitrary hinge axis point to true hinge axis point was as follows: Horizontal distance: AM: $-0.613{\pm}1.966mm$, PM: $-0.860{\pm}2.156mm$. Vertical distance: AM: $-0.886{\pm}2.518mm$, PM : $-1.226{\pm}2.660mm$. True hinge axis points had tendency to be located posterior-inferiorly to tragus-canthus line in the afternoon than in the morning, but there was not significant statistically. (P>0.1)

• Journal of the Korean Orthopaedic Association
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• v.56 no.5
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• pp.413-418
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• 2021

Purpose: To investigate the effect of facet tropism on the degeneration of facet joint and intervertebral disc in the cervical spine. Materials and Methods: From January 2017 to December 2018, cervical tropism of 100 patients at the C5/6 level was analyzed retrospectively. In computed tomography (CT), the orientation and tropism of the facet joint with respect to the sagittal, coronal, and horizontal planes were measured. Regression of the facet joint in magnetic resonance imaging (MRI) and CT was assessed using a grading system. Intervertebral disc degeneration was assessed and divided into five grades on MRI. For the left and right asymmetry, a difference between two facet angles of less than 7° was classified as the control group, more than 7° was classified as the tropism group. Results: The mean age of the patients was 55.44±12.3 years (31-81 years) in the tropism group and 55.66±10.7 years (32-76 years) in the control group. In the tropism group, 32 were male and 18 were female. In the control group, 24 were male and 26 were female. Facet joint degeneration was identified in 24 patients (48.0%) in the tropism group and 14 patients (28.0%) in the control group, showing a significant difference. Intervertebral disc degeneration was identified in 29 patients (58.0%) in the tropism group and 17 patients (34.0%) in the control group, showing a significant difference. Multivariate revealed, tropism to be a factor that affected the facet joint and intervertebral disc degeneration. Conclusion: Facet joint and intervertebral disc degeneration occurred significantly in the tropism group, and tropism is a factor affecting the degeneration of facet joint and intervertebral disc in the C5/6 level.

• International Journal of Highway Engineering
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• v.12 no.4
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• pp.101-110
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• 2010

In this paper, it has been studied about the CRCO to maintain or rehabilitate the aged JCP. The CRCO and JCO was constructed at useless section of Seo-Hae-Ahn express highway in South Korea. The performance evaluation was conducted. Especially, it was focused on the roll of longitudinal reinforced steels inserted into the CRCO. On crack survey results from field construction section, the reflection cracks at joint of the existing pavement occurred in CRCO. However, due to the constraints of longitudinal reinforced steels, crack width was small. Total crack length and quantity in the CRCO more than that in the JCO. And crack spacing in the CRCO was narrower than it in the CRCP. Through the bonding strength test results, if the cold milling and cleaning as well as surface treatment is applied, there will be no debonding problem at interlayer in the early age. From analysis of the horizontal behavior at the joint, the longitudinal reinforced steels constrained crack width which became wider than initial state over time. Also, that steel in the CRCO reduced the horizontal movement due to temperature variation(4 times than that in the JCO). But, if interface is debonded, the roll decreased. Vertical VWG data showed that CRCO did not occur debonding problem at steel location, but there was some problem in JCO. It was confirmed by field coring. The tensile strain appeared in the CRCO, But the compressive strain occurred in the JCO in early age. Through the FWD test result, deflection in the CRCO was less than that in the JCO. And K value in the CRCO was greater than it in the JCO.

• Journal of Ocean Engineering and Technology
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• v.25 no.6
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• pp.35-41
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• 2011

Recently, as large structures, which should support large design loads have been constructed, the study on the large diameter composite pile becomes necessary. The large diameter composite pile has the diameter over 700mm and consists of two parts of the upper steel pipe pile and the lower PHC pile by a mechanical joint. In this research, to analyze the bearing capacity and the material strength of the composite pile, three dimensional numerical analyses were performed. First, the numerical modeling method was verified by comparing the calculated load-movement curves of the pile with those of the field pile load tests. Then, a total of twelve analyses were performed by varying pile diameter and loading direction for three pile types of PHC, steel pipe and composite piles. The results showed that the vertical and the horizontal load-movement curves of the composite pile were identical with those of the steel pipe pile and the horizontal material strength of the composite pile was 60-80% larger than that of the PHC pile.

• Journal of Korean Neurosurgical Society
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• v.58 no.6
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• pp.578-581
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• 2015

A rigid spino-pelvic fixation to anchor long constructs is crucial to maintain the stability of long fusion in spinal deformity surgery. Besides obtaining immediate stability and proper biomechanical strength of constructs, the S2 alar-iliac (S2AI) screws have some more advantages. Four Korean fresh-frozen human cadavers were procured. Free hand S2AI screw placement is performed using anatomic landmarks. The starting point of the S2AI screw is located at the midpoint between the S1 and S2 foramen and 2 mm medial to the lateral sacral crest. Gearshift was advanced from the desired starting point toward the sacro-iliac joint directing approximately $20^{\circ}$ angulation caudally in sagittal plane and $30^{\circ}$ angulation horizontally in the coronal plane connecting the posterior superior iliac spine (PSIS). We made a S2AI screw trajectory through the cancellous channel using the gearshift. We measured caudal angle in the sagittal plane and horizontal angle in the coronal plane. A total of eight S2AI screws were inserted in four cadavers. All screws inserted into the iliac crest were evaluated by C-arm and naked eye examination by two spine surgeons. Among 8 S2AI screws, all screws were accurately placed (100%). The average caudal angle in the sagittal plane was $17.3{\pm}5.4^{\circ}$. The average horizontal angle in the coronal plane connecting the PSIS was $32.0{\pm}1.8^{\circ}$. The placement of S2AI screws using the free hand technique without any radiographic guidance appears to an acceptable method of insertion without more radiation or time consuming.

• Journal of Korean Society of Steel Construction
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• v.27 no.1
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• pp.119-129
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• 2015

Due to reduced self weight and alleviated wind effect, the multi-column wind towers that consist of a number of circular tubes as vertical members interconnected with horizontal brace members can be a substitute for the large-scale single cylinder wind towers. It is critical to guarantee strengths of tubular joints where vertical and horizontal members are structurally connected in order to make the whole multi-column system behave as a single tower structure. In this study, strength evaluation has been conducted for T-type tubular joints that are applicable in multi-column towers. Four of available design codes, i.e., AISC, Eurocode3, ISO 19902, CIDECT have been investigated and predictor equations in the considered design codes were validated and discussed through parametric numerical study on slenderness ratios of chords and braces at joints.

• Journal of Oral Medicine and Pain
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• v.12 no.1
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• pp.85-93
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• 1987

The author studied on the effect of TMJ sounds to the patterns and ranges of mandibular border movements in horizontal plane with Pantograph (Denar Corp.). For study, 19 patients with TMJ sounds only and 16 students with no TM disorder were selected and classified as experimental group and control group, respectively. The subject performed right lateral movement, left lateral movement, and forward movement. Each movement were performed 3 times and the movement trajectory obtained with mechanical pantograph were observed for accordance of centric relation position, reproducibility and/or restriction of lateral movement paths, deviation of protrusive path in anterior table, restriction of protrusive condylar movement path in posterior horizontal table, presence of Fisher angle in posterior vertical table. And pantographic reproducibility Index (PRI) were obtained with pantronic by the same movement method as in the mechanical pantograph record. The obtained results were as follows : 1. In experimental group, PRI scores in those who show accordance of centric relation position were 14.4, and were 26.53 in those who did not show accordance of centric relation position. However, the PRI scores of the two subgroups show no statistically significant difference in control group. Therefore, in experimental group, the capability of accordance of centric relation position affected largely the PRI scores than in control group. 2. Deviation of protrusive path was opposite to the affected side in experimental group, and was left side in control group. 3. Restriction side of condylar movement in protrusion was ipsilateral to the deviation side in experimental group, but in control group, restriction side was not related to the deviation side. 4. PRI scores in experimental group were 23.2 (moderate dysfunction category), and in control group, were 17.8 (slight dysfunction category). The PRI scores in control group, however, implies that the evaluation of temporomandibular disorders by the PRI scores only may be unreasonable.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.3
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• pp.255-261
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• 2007

Preface: Dental implant is important method that may solve the mastication, occlusion, esthetic, temporomandibular joint, and psychologic problem in oral and maxillofacial surgery. It is ideal that all of the implant are well positioned by adequate technique. By the way it‘s not always possible because of some anatomic, physiologic factor. In this case, If the implant can be moved to adequate position, it may be possible more esthetically and implanted patients more satisfied, but the majority of Implantists and orthodontists have thought that it is not possible. However, Implant, in fact, can be moved. and thus we can overcome the limit of implantation more. The aim of the present study was to evaluate the possibility of implant movement after corticotomy. Case report: Patient missed the upper right first molar. and implantation was done after completion of socket healing. We wait six months for osseointegration. Then, corticotomy was done under local anesthesia and close coil was used for orthodontic force. After traction during 3 weeks, we find the change of implant position at horizontal plane. we can not see the degenerative change on adjacent structure and tracted implant. there is a clinical mobility on upper right second premolar that used for anchorage but it subside spontaneously at the timing of prosthetic restoration without additional treatment. Discussion: As we could have some knowledge with this experiment, we report the case of implant movement after corticotomy and suggest a method about more esthetic implant treatment with a review of literature.