• 제목/요약/키워드: Continuous Strength Method

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An exploratory study on factors related to types of never-married among adult men and women (성인 비혼 남녀의 비혼 유형 관련 요인 탐색 연구)

  • Kim, Ji-Yu;Cho, Hee-Sun
    • Journal of Family Relations
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    • v.23 no.3
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    • pp.201-228
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    • 2018
  • Objectives: The objectives of this study were to classify never-married types of adult men and women and explore factors related to these types. Never-married types were categorized into 4 types according to continuity and voluntariness: continuous voluntary type; changed voluntary type; continuous non-voluntary type; and changed non-voluntary type. Factors related to types of being single were examined in terms of socio-demographic factors, individual and psychological factors (self-esteem, depression), dating relationship factors (current relationship status), original family factors (parental conflict, relationship with parents, parents' demand for marriage), marriage related factors (division of roles after marriage), and occupation related factors (work values, employment instability). Method: As for research method, a survey was conducted with never-married adult men and women between the ages of 35 and 49 living in Seoul, Gyeonggi or Incheon areas. Of 300 copies of questionnaire distributed, data from 295 copies were processed using SPSS 24.0 program for multinomial logit analysis. Results: The study results showed that, of never-married men respondents, continuous voluntary type accounted for 20.5%; changed voluntary type 18.9%; continuous non-voluntary type 49.6%; and changed non-voluntary type 11.0%. It was found that the factors related to continuous non-voluntary type among never-married men are age, religion, average monthly income, while the factors related to changed voluntary type are religion, self-esteem, depression, and frequency and strength of parental conflict, while the factor related to changed non-voluntary type men was living with parents. Examining never-married women respondents, it was found that, continuous voluntary type accounted for 33.9%; changed non-voluntary type 19.6%; continuous non-voluntary type 22.6%; and changed voluntary type 23.8%. The factor related to continuous non-voluntary type among never-married women was parents' demand for marriage, while the factors related changed voluntary type were age, depression and strength of parental conflict. Also, the factors related to changed non-voluntary type of never-married women were age, religion, living with parents, depression and parents' demand for marriage. Conclusion: In conclusion, it was found that continuous non-voluntary type formed the largest group among never-married men, whereas continuous voluntary type was the majority in never-married women. Both never-married men and women chose to remain single when they are living with their parents and their parental conflict is intense. Parents' demand for marriage was related to women, but not to men.

A STUDY ON THE PHYSICAL PROPERTIES AND VOLUMETRIC STABILITY OF SR-IVOCAP RESIN SYSTEM (SR-Ivocap resin system의 물리적 특성과 체적 안정성에 관한 연구)

  • Eun, Sung-Sik;Kweon, Hyeog-Sin;Chung, Chae-Heon
    • The Journal of Korean Academy of Prosthodontics
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    • v.36 no.3
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    • pp.453-467
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    • 1998
  • This study helps to clarify conflicting reports by comparing the physical properties and accuracy of complete denture processed by the pack and press technique, continuous- pressure injection technique(SR-Ivocap system) and Mark press technique. The 6 different specimens have been evaluated using the SEM, Impact test, DSC (Differential Scanning Calorimetry) and DMTA (Dynamic Mechanical Thermal Analysis). Each sample was made of SR-Ivocap resin and QC-20 resin by different processing methods. The results were as follows ; 1. As the result of the observation on the fracture surface of resin by use of SEM, sample SR-Ivocap resin cured by continuous pressure injection method showed the most homogeneous structure. This is why molecules in SR-Ivocap resin have no orientation. 2. As the result of the Impact test in order to measure the deformity, fracture energy and impact resistance of resin, the samples with QC-20 acrylic resin and SR-Ivocap resin cured by continuous pressure injection method were exellent. 3. In consequence of measuring ${\alpha}$-glass transition temperature by use of DSC on the basis of temperature change, the glass transition temperatures of sample QC-20 resin cured by pack and press method and sample SR-Ivocap resin cured by continuous pressure injection method were very similar. Thus volumetric stability could not be evaluated only by glass transition temperature. 4. In comparing volumetric stability data by DMTA, the glass transition temperature(Tg) showed $137.88^{\circ}C$ at sample QC-20 resin cured by pack and press method and $139.78^{\circ}C$ at sample SR-Ivocap resin cured by continuous pressure injection method. Therefore sample SR-Ivocap resin cured by continuous pressure injection method seems to be superior to sample QC-20 resin cured by pack and press method in the dimensional stability at high temperature. 5. In comparing storage modulus data by DMTA, the storage modulus of sample SR-Ivocap resin cured by continuous pressure injection method was higher than that of sample QC-20 resin cured by pack and press method. So. sample SR-Ivocap resin cured by continuous pressure injection method seems to be superior to sample QC-20 resin cured by pack and press method in impact strength.

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A Study on Strength Characteristics of Dredged Soft Clay (준설 연약 점토의 전단강도 특성에 관한 연구)

  • Lee, Song;Yun, Don-Kyu;Paik, Young-Shik
    • Geotechnical Engineering
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    • v.10 no.4
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    • pp.153-166
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    • 1994
  • In this paper, the experimental study on the behavior of the dredged clay was performed by introducing the consolidation teat method using continuous loading. Also a new testing method was examined and the strength of the dredged clay using thin plate was evaluated. The rheological characteristics of the dredged clay are described by the gingham model. The static and rheologic thin plate penetration test is proposed for the shear strength testing method. It is found that both of testing methods are reasonable and have a practicability. Especially, the strength increases for a water content which is less than two times of liquid limit in case of silty soil and clayey soil. About plasticity index, the strength increases rapidly for a value less than 10 for silt, 5 for clay which a water content is normalized by plasticity index of silty soil rather than clayey soil.

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A Study on Discontinuum Analysis and Continuum Analysis of Tunnels in Jointed Rock Mass (절리발달 암반터널의 불연속체해석과 연속체해석에 관한 고찰)

  • Cho Sun-Kyu;Kim Si-Kyeok;Kim Do-Hoon
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.1089-1094
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    • 2004
  • Numerical methods to estimate behaviors of jointed rock mass can be roughly divided into two method : discontinuous model and continuum model. Generally, distinct element method (DEM) is applied in discontinuous model, and finite element method (FEM) or finite difference method (FDM) is utilized in continuum model. To predict a behavior of discontinuous model by DEM, it is essential to understand characteristics of joints developed in rock mass through field tests. However, results of field tests can not provide full information about rock mass because field tests is conducted in limited area. In this paper, discontinuous analysis by UDEC and continuous analysis by FLAC is utilized to estimate a behavior of a tunnel in jointed rock mass. For including discontinuous analysis in continuous analysis, joints in rock mass is considered by reducing rock mass properties obtained by RMR and decreasing shear strength of rock mass. By comparing and revising two analysis results, analysis results similar with practical behavior of a tunnel can be induced and appropriate support system is decided.

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Preliminary Structural Design of Wall-Frame Systems for Optimum Torsional Response

  • Georgoussis, George K.
    • International Journal of Concrete Structures and Materials
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    • v.11 no.1
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    • pp.45-58
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    • 2017
  • Recent investigations have pointed out that current code provisions specifying that the stiffness of reinforced concrete elements is strength independent, and therefore can be estimated prior to any strength assignment, is incorrect. A strength allocation strategy, suitable for preliminary structural design of medium height wall-frame dual systems, is presented for allocating strength in such buildings and estimating the dependable rigidities. The design process may be implemented by either the approximate continuous approach or the stiffness matrix method. It is based on the concept of the inelastic equivalent single-degree-of-freedom system which, the last few years, has been used to implement the performance based seismic design. The aforesaid strategy may also be used to determine structural configurations of minimum rotation distortion. It is shown that when the location of the modal centre of rigidity, as described in author's recent papers, is within a close distance from the mass axis the torsional response is mitigated. The methodology is illustrated in ten story building configurations, whose torsional response is examined under the ground motion of Kobe 1995, component KJM000.

A Study on the Improvement Buckling Strength of Laminated Composite Plate by Taguchi Method (다구찌법을 이용한 복합적층판의 좌굴강도 개선에 관한 연구)

  • 구경민;홍도관;김동영;박일수;안찬우;한근조
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1362-1365
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    • 2003
  • On this study. we improved the efficiency applying algorithm that is repeatedly using orthogonal array in discrete design space and filling a defect of gradient method in continuous design space. we showed optimal ply angle that maximized buckling strength of CFRP laminated composite plate without a hole and with a hole by each aspect ratio. In the case of CFRP laminated composite plate without a hole, we confirmed the reliance and efficiency of algorithm in comparison with the result optimization achievement repeatedly using statistical orthogonal array of experimental design.

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A New Method to Fabricate Bulk PCMs from Continuous Wires and the Mechanical Behaviors (연속된 와이어를 이용한 다층 PCM의 제조방법 및 특성 평가)

  • Lee, Yong-Hyun;Choi, Ji-Eun;Jeon, In-Su;Kang, Ki-Ju
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.31 no.2 s.257
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    • pp.245-252
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    • 2007
  • Since the new millennium, truss PCMs(Periodic Cellular Metals) have drawn attention because of their superior specific stiffness, strength and multi-functionality. Prior studies have focused on the structural design and optimization. Kagome truss PCM has been proved to have the higher resistance to plastic buckling, more plastic deformation energy and lower anisotropy than other truss PCMs. In this study, we introduce a new idea to fabricate multi-layered Kagome truss PCM from continuous wires which can gain high strength as in piano wires and can be controlled to be defect free owing to drawing process. The relative density, the stiffness and the strength under bending and compressive load are estimated through elementary mechanics and compared with the results from experiments and FEA. The failure mechanisms are analyzed, and also mechanical performance and production are discussed.

Evaluation of Bending Fatigue Testing of Austempered Ductile Iron Spur Gears (오스템퍼링 구상흑연주철 평기어의 굽힘피로시험평가에 관한 연구)

  • Lv, Jian Hua;Zhou, Rui;Xu, Yang;Qin, Zhen;Zhang, Qi;Lyu, Sungki
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.19 no.12
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    • pp.1-7
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    • 2020
  • An experimental evaluation of bending fatigue strength for austempered ductile iron (ADI) spur gears was performed using a Zwick fatigue tester. The gear material was manufactured using vertical continuous casting, resulting in the radius of the graphite grains being smaller. The stress-number of cycles curve (S-N curve) for the bending fatigue strength of the ADI spur gears thus manufactured, without any specific surface treatments, was obtained using post-processing software. It was observed that when the reliability was 50%, the allowable root stress was 610 MPa. was calculated using an analytical method as well as the finite element method, and the difference between the values calculated using the two methods is only 7%. This study provides a reliable basis to rate the reliability design of small gearboxes in automation in the future.