• Title/Summary/Keyword: Component Design

Search Result 3,797, Processing Time 0.028 seconds

Biomechanical Analysis of Different Thoracolumbar Orthosis Designs using Finite Element Method (유한요소 해석을 이용한 정형용 흉·요추 보조기의 형태에 따른 생체역학적 분석)

  • Kim, Y.H.;Jun, S.C.;Jung, D.Y.;Lee, S.J.
    • Journal of rehabilitation welfare engineering & assistive technology
    • /
    • v.6 no.1
    • /
    • pp.45-50
    • /
    • 2012
  • Thoracolumbar orthosis has been used for the rehabilitation of the patients with senile kyphosis. Recently, a number of different thoracolumbar orthosis designs have been introduced but its biomechanical effectiveness still remain unknown. In this study, we compared the pressure distribution on the surface of the trunk and stresses on the orthosis in relation to changes in connecting frame designs (Type 1, one-connecting frame type; Type 2, two-connecting frame type; Type 3, all-in-one type) using finite element (FE) models under different motions of the trunk. The results showed that Type 3 distributed the pressure on the trunk most evenly followed by Type 2 and Type 1 and the difference between Type 1 and Type 2 was negligible. ROM was limited most effectively by Type 3 ($8.5{\sim}9.4^{\circ}$), followed by Type 2 ($11.3{\sim}13.9^{\circ}$) and Type 1 ($12.1{\sim}15.4^{\circ}$). The ratio between the peak von Mises stress and yield strength of each material remained less than 20% regardless of orthosis type indicating low likelihood of component failure. In conclusion, our study found that all-in-one type of orthosis was the most effective design for the conservative treatment of spinal deformity in terms of function and comfort.

  • PDF

Design and Analysis of LED.Optical Fiber Coupler for Efficient Line Lamps (효율적인 라인램프를 위한 발광다이오드-광섬유 결합기의 설계 및 해석)

  • Hong, Dae-Woon;Yoon, Myeong-Jung;Kim, Kyung-Ho;Yoo, Jae-Keun;Lee, Song-Jae
    • Korean Journal of Optics and Photonics
    • /
    • v.21 no.1
    • /
    • pp.26-32
    • /
    • 2010
  • Line lamps, which utilize leaky optical fibers based on periodic bending of plastic optical fibers, are proposed. The LED-optical fiber coupler, the key component of the line lamp, is designed and analyzed. The analysis by the Monte Carlo photon simulation method has shown that the optical coupling efficiency is affected rather sensitively by $\theta_w$, the slanting angle of the reflecting cup sidewall and $\rho_{ref}$, the reflectivity of the reflecting cup. The optical coupling efficiency of the coupler reaches the maximum when $\theta_w$ is about $60^{\circ}$, which is significantly larger than $\theta_w=45^{\circ}$, the typical sidewall slanting angle of the reflecting cup adopted in most LED lamps. When the reflectivity of the reflecting cup is above 0.8, the optical coupling efficiency is larger than 80%, which is the typical efficiency to be achieved in LD-optical fiber coupler.

Towards a Pedestrian Emotion Model for Navigation Support (내비게이션 지원을 목적으로 한 보행자 감성모델의 구축)

  • Kim, Don-Han
    • Science of Emotion and Sensibility
    • /
    • v.13 no.1
    • /
    • pp.197-206
    • /
    • 2010
  • For an emotion retrieval system implementation to support pedestrian navigation, coordinating the pedestrian emotion model with the system user's emotion is considered a key component. This study proposes a new method for capturing the user's model that corresponds to the pedestrian emotion model and examines the validity of the method. In the first phase, a database comprising a set of interior images that represent hypothetical destinations was developed. In the second phase, 10 subjects were recruited and asked to evaluate on navigation and satisfaction toward each interior image in five rounds of navigation experiments. In the last phase, the subjects' feedback data was used for of the pedestrian emotion model, which is called ‘learning' in this study. After evaluations by the subjects, the learning effect was analyzed by the following aspects: recall ratio, precision ratio, retrieval ranking, and satisfaction. Findings of the analysis verify that all four aspects significantly were improved after the learning. This study demonstrates the effectiveness of the learning algorithm for the proposed pedestrian emotion model. Furthermore, this study demonstrates the potential of such pedestrian emotion model to be well applicable in the development of various mobile contents service systems dealing with visual images such as commercial interiors in the future.

  • PDF

Analysis of Streetscape Image in Cultural District Using Structural Equation Model (구조방정식을 이용한 문화예술의 거리의 가로경관 이미지 분석)

  • Kim, Myung Soo
    • International Journal of Highway Engineering
    • /
    • v.16 no.6
    • /
    • pp.137-147
    • /
    • 2014
  • PURPOSES : Daejeon is basically divided into an old downtown and a new downtown, and the recent relocation of the Chungcheongnam-do Provincial Government of Republic of Korea from the old downtown and the opening of governmental buildings in the new downtown as well have made this new downtown only densely populated with industrial and business facilities. Such changes in the downtowns have promoted the conditions of the new downtown while, consequently, dragging down the old downtown. Out of concern for those unbalanced developments of the two downtowns, Daejeon is now carrying out several city projects to revive the old downtown. In the light of that, as a part of the project to promote the old downtown, this study aims to conduct an evaluation on landscape of the culture and arts street in Daeheungdong which was built upon those ideas of a theme street project by Daejeon. METHODS : Based on the findings from the questionnaire not only on the components that would design the streetscape of the culture and arts street but also on the public satisfaction with the streetscape, the study defined how those changes in the components affect emotional factors of the pedestrians. In order to achieve the research goal, the study made changes in D/H ratio of the street structural components as well as the roadside trees. In terms of the questionnaire method, the study used the SD scale, and proceeded with its investigation through the frequency analysis, the principal component analysis (the factor analysis) and the structural equation model. RESULTS : According to the results from the factor analysis and the regression analysis, of those three factors, such as the openness, the comfortable sensation and the safety, the openness followed by the comfortable sensation and the safety was determined to have the most positive influence on the total satisfaction. The structural model analysis reported that the D/H and the structural components of the roadside trees and planting have a positive effect on the emotional image, and this emotional image also appeared to be positively related to the total satisfaction. CONCLUSIONS : This study looked into how the changes in the street structural components of the culture and arts street in Daeheungdong would affect the satisfaction with the streetscape, and finally confirmed that the D/H and the planting are what would have a positive effect on this satisfaction. What has been learned from this study will be the basic data to figure out how to promote and improve the culture and arts street in Daeheung-dong as this data will also help designing and developing of those specialized streets in other regions.

Implementing Special Transportation Management Zone System for Dongdaemoon Garment District (동대문 의류밀집상가 교통혼잡특별관리구역 사례연구)

  • 황기연;엄진기;이종운;조용학
    • Journal of Korean Society of Transportation
    • /
    • v.18 no.6
    • /
    • pp.7-17
    • /
    • 2000
  • The Purpose of this study is to test the effectiveness of Special Transportation Management Zone system (TZ) when it is applied to Dongdaemoon commercial zone located in downtown Seoul. The study consists of two Parts ; the legal components of TZ and the case study on Dongdaemoon district. The case study includes the analysis of current traffic situation on the study zone, the design of implemention alternative for each component of TZ, the framework of impact analysis system, and the analysis results. The study finds, if 2,000 won mandatory parking fee on drivers parking in the buildings only with over 10 parking spaces and over 3.000$m^2$ in floor area, strong illegal parking enforcement, and Pro-hibition of parking passenger cars whose last digit plate number matches with the last digit of date, are implemented in the zone simultaneously, the traffic speed increases to 20.56km/h which is above the target set in the zone. In conclusion, we find that TZ2 can be an effective tool relieving traffic congestion in Seoul, and that it is necessary for introducing TZ in Seoul that relevant laws should be revised and expecting problems should be overcome.

  • PDF

The Study on the Development and the Applicability of Consolidation Analysis Program Considering the Creep Strain (Creep 변형을 고려한 압밀해석 프로그램의 개발과 적용성 분석)

  • Kim, Su-Sam;Jeong, Seung-Yong;An, Sang-Ro
    • Geotechnical Engineering
    • /
    • v.14 no.5
    • /
    • pp.129-142
    • /
    • 1998
  • This research is focused on the inducement of the constitutive equation considering the creep strain component and on the development of a finite element method program. The purpose of this research was to contribute to the design of construction structures or to the construction management in soft clay ground through predicting the long-term strain of construction structures reasonably bused on the above program. Modified Cam Clay model was adopted to describe the elastic-plastic behavior of clayey soil. And in the calculation of the creep sprain, the secondary coefficient of consolidation C. was applied for considering the volumetric creep element and the constants m, $\alpha$, A were rosed by the empirical creep equation proposed by Singh 8E Mitchell for considering the deviatoric creep element. To examine the reliability of the program which is developed in this study, the estimated values by this program were compared with the theoretical solution and the experimental results. And the applicability of the developed program was found to be reliable from the sensitive analysis of each parameters used in this study. According to the results obtained from the application of the program on the field measurement data, the estimated values by the program were found with be consistent with the actual values. And from the analysis of the displacement of embankments, the case of considering the creep behavior induced much fower errors than the case of neglecting it. But the results obtained from considering the volumetric creep behavior only were slightly underestimated the results from considering the deviator creep behavior showed the slightly overestimated values. Therefore, it remains the task of further studios to develop the laboratory test devices to obtain the reliable creep parameters, and to select the appropriate soil parameters, etc.

  • PDF

Effects of ruminally degradable starch levels on performance, nitrogen balance, and nutrient digestibility in dairy cows fed low corn-based starch diets

  • Luo, Guobin;Xu, Wenbin;Yang, Jinshan;Li, Yang;Zhang, Liyang;Wang, Yizhen;Lin, Cong;Zhang, Yonggen
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.30 no.5
    • /
    • pp.653-659
    • /
    • 2017
  • Objective: This trial was performed to examine the effects of ruminally degradable starch (RDS) levels in total mixed ration (TMR) with low corn-based starch on the milk production, whole-tract nutrient digestibility and nitrogen balance in dairy cows. Methods: Eight multiparous Holstein cows (body weight [BW]: $717{\pm}63kg$; days in milk [DIM]: $169{\pm}29$) were assigned to a crossover design with two dietary treatments: a diet containing 62.3% ruminally degradable starch (% of total starch, low RDS) or 72.1% ruminally degradable starch (% of total starch, high RDS). Changes to the ruminally degradable levels were conducted by using either finely ground corn or steam-flaked corn as the starch component. Results: The results showed that dry matter intake, milk yield and composition in dairy cows were not affected by dietary treatments. The concentration of milk urea nitrogen was lower for cows fed high RDS TMR than low RDS TMR. The whole-tract apparent digestibility of neutral detergent fiber, acid detergent fiber and crude protein decreased, and that of starch increased for cows fed high RDS TMR over those fed low RDS TMR, with no dietary effect on the whole-tract apparent digestibility of dry matter and organic matter. The proportion of urinary N excretion in N intake was lower and that of fecal N excretion in N intake was higher for cows fed high RDS TMR than those fed low RDS TMR. The N secretion in milk and the retention of N were not influenced by the dietary treatments. Total purine derivative was similar in cows fed high RDS TMR and low RDS TMR. Consequently, estimated microbial N flow to the duodenum was similar in cows fed high RDS TMR and low RDS TMR. Conclusion: Results of this study show that ruminally degradable starch levels can influence whole-tract nutrient digestibility and nitrogen balance in dairy cows fed low corn-based starch diets, with no influence on performance.

Hydrodynamic Analysis of Submerged Floating Tunnel Structures by Finite Element Analysis (유한요소해석을 통한 해중터널의 유체동역학 해석)

  • Kim, Seungjun;Park, Woo-Sun;Won, Deok-Hee
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.36 no.6
    • /
    • pp.955-967
    • /
    • 2016
  • As transportation systems for connecting lands and islands, oversea long-span bridges, underwater tunnels, and immersed tunnels have been mainly used so far. Submerged floating tunnels (SFTs) moored under specific water depth are one of the newest oversea transportation system. Compared to other existing systems, the new system requires relatively less construction cost and time. But, there is still no construction example. For reasonable design of the tunnel and mooring lines the rational structural analysis should be firstly performed. Unlike common transportation structures, the submerged tunnels are mainly affected by the wave, vary irregular excitation component. So, the analysis scheme might be difficult because of the characteristics of the submerged structures. This study aims to suggest the rational global performance analysis methodology for the submerged tunnels. Using ABAQUS the dynamic response of the experimental models studied by KIOST (2013) was investigated considering regular waves. By comparing the simulation results with the experimental results, the feasibility of the numerical simulation was verified. Using the suggested method, the effects of initial inclination of the tethers and draft of the tunnel on the dynamic behavior were studied. In addition, dynamic response of a SFT under the irregular wave was examined.

Experimental Investigation on Torsional Analysis and Fracture of Tripod Shaft for High-speed Train (고속열차용 트리포드 축의 비틀림 해석 및 파단에 대한 실험적 연구)

  • Lee, Joo Hong;Kim, Do Sik;Nam, Tae Yeon;Lee, Tae Young;Cho, Hae Yong
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.40 no.11
    • /
    • pp.979-986
    • /
    • 2016
  • The tripod shafts of constant-velocity joint are used in both the trains KTX and KTX-sanchon. It is an important component that connects the motor reduction unit and the axle reduction unit in a power bogie. The tripod shaft not only transmits drive and brake torque in the rotational direction, but also slides in the axial direction. If the drive system is loaded with an excessive torque, the fuse part of the shaft will be fractured firstly to protect the other important components. In this study, a rig was developed for conducting torsion tests on the tripod shaft, which is a type of mechanical fuse. The tripod shafts were subjected to torsional fracture test and torsional fatigue test on the rig. The weak zone of the tripod shaft was identified, and its fatigue life was predicted using finite element analysis (FEA). After analyzing the FEA results, design solutions were proposed to improve the strength and fatigue life of the tripod shaft. Furthermore, the deterioration trend and time for failure of the tripod shaft were verified using the hysteresis loops which had been changed with the advancement of the torsional fatigue test.

MLH1 Polymorphisms and Cancer risk: a Meta-analysis Based on 33 Case-control Studies

  • Xu, Jia-Li;Yin, Zhi-Qiang;Huang, Ming-De;Wang, Xie-Feng;Gao, Wen;Liu, Ling-Xiang;Wang, Rong-Sheng;Huang, Pu-Wen;Yin, Yong-Mei;Liu, Ping;Shu, Yong-Qian
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.13 no.3
    • /
    • pp.901-907
    • /
    • 2012
  • Objective: Cumulative evidence suggests that MLH1, the key component in the mismatch pathway, plays an important role in human cancers. Two potential functional polymorphisms (-93G>A and I219V) of MLH1 have been implicated in cancer risk. The aim of this meta-analysis was to summarize the evidence for associations. Methods: Eligible studies were identified by searching the electronic literature PubMed, ScienceDirect and Embase databases for relevant reports and bibliographies. Studies were included if of case-control design investigating MLH1 polymorphisms (-93G>A and I219V) and cancer risk with sufficient raw data for analysis. Odds ratios (OR) and 95% confidence intervals (95% CI) were used to evaluate the strength of associations. Results: Our meta-analysis from 33 published case-control studies showed the variant A allele of -93G>A polymorphism to be associated with increased risk in all genetic models (AA vs. GG: OR = 1.22, 95% CI: 1.03-1.44), especially among non-Asians (AA vs. GG: OR = 1.28, 95% CI: 1.04-1.58). For the I219V polymorphism, however, there was no main effect associated with overall cancer risk in any genetic model. Conclusions: The meta-analysis suggested that the MLH1 -93G>A polymorphism may be a biomarker of cancer susceptibility. Large sample association studies and assessment of gene-to-gene as well as gene-to-environment interactions are required to confirm these findings.