• Title/Summary/Keyword: Horizontal plane

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Seismic Reliability Analysis of Offshore Wind Turbine with Twisted Tripod Support using Subset Simulation Method (부분집합 시뮬레이션 방법을 이용한 꼬인 삼각대 지지구조를 갖는 해상풍력발전기의 지진 신뢰성 해석)

  • Park, Kwang-Yeun;Park, Wonsuk
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.32 no.2
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    • pp.125-132
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    • 2019
  • This paper presents a seismic reliability analysis method for an offshore wind turbine with a twisted tripod support structure under earthquake loading. A three dimensional dynamic finite element model is proposed to consider the nonlinearity of the ground-pile interactions and the geometrical characteristics of the twisted tripod support structure where out-of-plane displacement occurs even under in-plane lateral loadings. For the evaluation of seismic reliability, the failure probability was calculated for the maximum horizontal displacement of the pile head, which is calculated from time history analysis using artificial earthquakes for the design return periods. The application of the subset simulation method using the Markov Chain Monte Carlo(MCMC) sampling is proposed for efficient reliability analysis considering the limit state equation evaluation by the nonlinear time history analysis. The proposed method can be applied to the reliability evaluation and design criteria development of the offshore wind turbine with twisted tripod support structure in which two dimensional models and static analysis can not produce accurate results.

Evaluation of Skeletal and Dental Maturity in Relation to Vertical Facial Types and the Sex of Growing Children (성장기 아동의 수직적 안모 형태와 성별에 따른 골격적 성숙도와 치아 성숙도 평가)

  • Jo, Seon-Gyeong;Kim, Byounghwa;Lee, Jewoo;Ra, Jiyoung
    • Journal of the korean academy of Pediatric Dentistry
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    • v.48 no.4
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    • pp.414-424
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    • 2021
  • The purpose of this retrospective study was to evaluate the skeletal and dental maturity according to the vertical facial type and sex in Korean children in the developmental stage. In total, 184 participants aged 8 - 14 years were selected and divided into three groups based on the mandibular plane angle. For the comparison between the sexes, the three groups were each divided into male and female subgroups. The skeletal and dental maturity were assessed using lateral cephalograms, hand-wrist radiographs and panoramic radiographs. The vertical growth group showed significantly greater cervical vertebral and hand-wrist maturity than that in the horizontal growth group. Dental maturity was the highest in the vertical growth group. Girls showed greater skeletal maturity than boys, and no distinct difference was observed between the dental maturity of the sexes. Analysis of the vertical facial type in children can provide ancillary indicators that may help determine the optimal timing for orthodontic treatment initiation. Earlier initiation of orthodontic treatment may be considered for patients with vertical facial growth patterns.

Stress distribution following face mask application using different finite element models according to Hounsfield unit values in CT images (CT상의 HU 수치에 따른 상악골 전방견인 효과의 유한요소 분석)

  • Chung, Dong-Hwa
    • The korean journal of orthodontics
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    • v.36 no.6
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    • pp.412-421
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    • 2006
  • Objective: The result of finite element analysis depends on material properties, structural expression, density of element, and boundar or loading conditions. To represent proper elastic behavior, a finite element model was made using Hounsfield unit (HU) values in CT images. Methods: A 13 year 6 month old male was used as the subject. A 3 dimensional visualizing program, Mimics, was used to build a 3D object from the DICOM file which was acquired from the CT images. Model 1 was established by giving 24 material properties according to HU. Model 2 was constructed by the conventional method which provides 2 material properties. Protraction force of 500g was applied at a 45 degree downward angle from Frankfort horizontal (FH) plane. Results: Model 1 showed a more flexible response on the first premolar region which had more forward and downward movement of the maxillary anterior segment. Maxilla was bent on the sagittal plane and frontal plane. Model 2 revealed less movement in all directions. It moved downward on the anterior part and upward on the posterior part, which is clockwise rotation of the maxilla. Conclusion: These results signify that different outcomes of finite element analysis can occur according to the given material properties and it is recommended to use HU values for more accurate results.

Prediction of Hydrodynamic Coefficients for Underwater Vehicle Using Rotating Arm Test (강제선회시험을 이용한 수중운동체의 유체력 미계수 추정)

  • Jeong, Jae-Hun;Han, Ji-Hun;Ok, Jihun;Kim, Hyeong-Dong;Kim, Dong-Hun;Shin, Yong-Ku;Lee, Seung-Keon
    • Journal of Ocean Engineering and Technology
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    • v.30 no.1
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    • pp.25-31
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    • 2016
  • In this study, hydrodynamic coefficients were obtained from a Rotating Arm (RA) test, which is one of the captive model tests used to provide accurate coefficients in the control motion equation of an underwater vehicle. The RA test was carried out at the RA facility of ADD (Agency for Defense Development), and the forces and moments acting on the underwater vehicle were measured using a six-axis waterproof gage. A multiple regression analysis was used in the analysis of the measured data. The experimental results were also verified by comparison with the theoretical values of the previous linear coefficients. In addition, the stability indices in the horizontal plane were calculated using the linear and nonlinear coefficients, and the dynamic stability of the underwater vehicle was estimated to have a good dynamic performance with a depth ratio of 6.0.

The Effects of Visual Direction Control on Balance and Gait Speed in Patients with Stroke (뇌졸중 환자의 시선 방향 조절이 균형과 보행에 미치는 영향)

  • Kwon, Hye-Rim;Shin, Won-Seob
    • Journal of the Korean Society of Physical Medicine
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    • v.8 no.3
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    • pp.425-431
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    • 2013
  • PURPOSE: The purpose of this study was to examine the effect of visual control on gait speed and balance in patients with stroke. Static balance and gait speed were investigated with comparison and fixed direction of visual. METHODS: We included twenty-six patients with stroke. Participants were measured static balance while standing on a forceplate with one of 4 different visual direction in front, floor, non-affected side and affected side for 30 seconds. To compare of the gait speed, participants had to walk with one of fixed visual direction. And to compare of gait speed with visual dispersion, gait speed were measured with visual change in left and right, up and down direction every 5m, 2m and 1m intervals. RESULTS: The result of the static balance with fixed visual showed that the affected side and the non-affected side were shown significantly increased sway of total sway length, mediolateral distance, anteroposterior distance, average velocity(p<.05). The gait speed with fixed visual showed that affected side was significantly slower(p<.05). And the gait speed significantly increased as interval of visual dispersion decrease in the sagittal and horizontal plane(p<.05). CONCLUSION: The results from this study showed that the visual direction effected on static balance and the faster visual movement made to increase the gait speed. Therefore the rehabilitation training with visual control may be implemented for stroke patients.

Cone-beam computed tomography of mandibular foramen and lingula for mandibular anesthesia

  • Ahn, Byeong-Seob;Oh, Song Hee;Heo, Chong-Kwan;Kim, Gyu-Tae;Choi, Yong-Suk;Hwang, Eui-Hwan
    • 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.

Full mouth rehabilitation of deep bite patient with segmental osteotomy and orthodontic treatment (분절골절단술과 교정치료를 동반한 과개교합 환자의 완전구강회복 증례)

  • Chu, Seung-Sik;Cho, Woong-Rae;Huh, Yoon-Hyuk;Park, Chan-Jin;Cho, Lee-Ra
    • The Journal of Korean Academy of Prosthodontics
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    • v.53 no.1
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    • pp.26-38
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    • 2015
  • Teeth wear and extrusion of antagonist are commonly observed in deep bite patient having severe vertical and horizontal overlap. These problems cause collapse of occlusal plane and abnormal anterior guidance. Without restoring harmonious occlusion, loss of multiple teeth and decreased masticatory function could not be prevented. To resolve problems associated with deep bite, multidisciplinary treatment including oral surgical, orthodontic and prosthetic treatment should be performed. This clinical report describes the results of increasing occlusal vertical dimension with a full-mouth restoration procedure. The treatment procedures include extraoral and intraoral examination, diagnosis, treatment planning, diagnostic wax-up, segmental osteotomy, orthodontic intrusion and prosthodontic rehabilitation. Full mouth rehabilitation with increasing occlusal vertical dimension can solve esthetic and functional problems.

The Development of Men's Dress Form for Pattern Making (패턴메이킹을 위한 남성(男性) 인대개발(開發)에 관(關)한 연구(硏究))

  • Yoo, Hyun;Shim, Boo-Ja
    • 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.

A PHOTOMETRIC STUDY OF MAXILLOFACIAL NORMALS IN $14{\sim}15$ YEAR-OLD KOREAN. (($14{\sim}15$세 한국인 안모의 실물사진계측분석에 의한 연구)

  • Oh, Jae-Kwon;Kim, Yeo-Gab
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.23 no.2
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    • pp.115-123
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    • 2001
  • The primary method of diagnosis in craniofacial deformity patient is used by gross inspection. The study for objective analysis and evaluation in Korean maxillofacial soft tissue portions is rare and our normals have been based on Caucasian such as American. But it is difficult to apply it to ours so we studied the frontal photometric measurements for maxillofacial Korean normals. The photograph were taken with the subject sitting in head position parallel with interpupillary plane to the floor. During taking pictures, facial analyser by Obwegeser in Martin was used for correct measurements. 54 male and 57 female ages 14 to 15 years were selected from a group of 111 healthy middle school students in Inchon. 1. The vertical measurements in glabella-subnasale, subnasale-stomion and stomion-menton in the male were higher than in the female subjects in $14{\sim}15$ years old Korean, so middle and lower third face were higher than those of female(p<0.05). 2. The horizontal measurements of female was higher than those of male in the rt. and It. eye width but smaller in nose width and lip width(p<0.05). 3. There was no significant difference in gender compared with soft cheek and mention angle measurements When our reports were compared with american white population, the vertical proportions in Korean normals were similar to american and the line measurements in middle facial length, nose width and intercanthal distance were higher than those of american.

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The Impact Loads on the Hitch Point of the Tiller-Trailer System (동력경운기의 경사지 견인 및 주행 특성에 관한 연구(제일보)-동력경운기 -트레일계의 힛치점에 작용하는 충격력-)

  • 송현갑;장창주
    • 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.

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