• 제목/요약/키워드: Theoretical model

검색결과 5,854건 처리시간 0.034초

수술 직후 암 환자의 희망증진 간호를 위한 이론 모델 개발 : 현실적 희망 (A Theoretical Model of Hope Enhancing the Cancer Patients just after Surgery: Realistic Hope)

  • 김달숙;박인숙
    • 성인간호학회지
    • /
    • 제18권1호
    • /
    • pp.115-124
    • /
    • 2006
  • Purpose: The purpose of this study was to propose a theoretical model of hope commonly held by the cancer patients just after surgery, under the assumptions that hope of those patients is not only realistic and disease oriented but in dialectical circulation. Method: A theoretical model was generated through 4 steps: exploring a hope structure by synthesizing the relevant hope structures expressed in Kim and Tae's studies, in-depth literature review, examining the meanings of the concepts consisted of the structure in use and their causal relations in logical adequacy, proposing a theoretical structure through synthesizing the causal relations, and diagramming the structure. Results: The proposed theoretical model involves concepts such as Cancer Related Uncertainty (CRU), Efforts to Find out the Possibility of Cure or Recovery (EFPCR), and Hopefulness or Hopelessness. The 'EFPCR' is stipulated as 'Behaviors Related to Looking for Evidences or Cues (BRLEC)' and 'Formation of Cognitive Schema (FCS)'. In the model, Hopefulness is directly influenced by 'CRU in low', which is affected by 'FCS in good' from the result of EFPCR started with 'CRU in increase' while 'CRU with increase' from the result from EFPCR has direct effect on Hopelessness. Conclusion: The theoretical model would be used to enhancing hope of the cancer patients in post-operation.

  • PDF

Vortex-induced oscillations of bridges: theoretical linkages between sectional model tests and full bridge responses

  • Zhang, Zhitian;Ge, Yaojun;Chen, Zhengqing
    • Wind and Structures
    • /
    • 제19권3호
    • /
    • pp.233-247
    • /
    • 2014
  • Vortex-induced oscillation is a type of aeroelastic phenomenon, to which extended structures such as long-span bridges are most susceptible. The vortex-induced vibration (VIV) behaviors of a concerned bridge were investigated conventionally in virtue of wind tunnel tests on string-mounted sectional models. This necessitates the building of a linkage between the response of the sectional model and that of the prototype structure. Although many released literatures have related to this issue and provided suggestions, there is a lack of consistency among them. In this study, some theoretical models describing the vortex-induced structural motion, including the linear empirical model, the nonlinear empirical model and the modified (or generalized) nonlinear empirical model, are firstly reviewed. Then, the concept of equivalent mass density is introduced based on the principle that an equal input of energy should result in identical structural amplitudes. Based on these, the theoretical linkages between the amplitude of a section model and that corresponding to the prototype bridge are discussed with different analytical models. Theoretical derivation indicates that such connections are dependent mainly on two factors, one is the presupposed shape of deformation, and the other is the theoretical VIV model employed. The theoretical analysis in this study shows that, in comparison to the nonlinear empirical models, the linear one can result in obvious larger estimations of the full bridges' responses, especially in cases of cable-stayed bridges.

단순 Box형 Cut-out 차체모델의 경량화를 위한 이론적 개념설계 모델 연구 (A Study on a Theoretical Conceptual Design Model to Reduce the Weight of a Simple Box-type Cut-out Carbody)

  • 조정길;구정서;정현승
    • 한국철도학회:학술대회논문집
    • /
    • 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
    • /
    • pp.2666-2671
    • /
    • 2011
  • In this paper, a theoretical approach was studied to make a baseline box type model satisfying the stiffness condition of a cut-out model. First, we compared the sum of the sectional theoretical deflections and the FEM result of the cut-out model under the static load test conditions, and we obtained good correlations from both the results. Second, To obtain the thickness of the baseline model, we used the mean value of geometric moment of intertia of the side wall and roof structure. Also, we compared the theoretical results and the FEM result of a baseline model, and we obtained good correlations. It is considered that the developed theoretical approach can be used for the weight reduction of train carbodies.

  • PDF

Note on Debate over Relationship Between Business Model and Strategy

  • PARK, Kyoo-Ho
    • 동아시아경상학회지
    • /
    • 제10권4호
    • /
    • pp.39-45
    • /
    • 2022
  • Purpose - This short paper reviews the debate dealing with the relationship between strategy and traditional strategy approach on the one hand, and business models and new business model approach on the other hand and tries to offer useful direction to be more helpful to theoretical discussions. Research design, data, and methodology - This paper makes a theoretical analysis to explain the confusion surrounding the debate, reviewing mainly literature survey papers and finds theoretical conjecture and its limitations in order to present useful direction to the future theoretical work. Result - In order to comprise its diversity, business model studies should consider the characteristics of each firm, sector, and market. Adding further elements which are related to each sector or market, theoretical studies can capture the diverse phenomena related to business model and business model innovation. Conclusion - The traditional strategy perspective can be utilized to the Business model phenomenon in the case of incumbent firms and non-digital sector and existing markets. Meanwhile the new business model perspective can be utilized to business model phenomena in case of start-ups and digital sector and emerging markets. Reconciling two perspectives, the studies dealing with the business model should focus on the characteristics of firms, markets, and knowledge from the perspective of business model innovation.

Wind-induced random vibration of saddle membrane structures: Theoretical and experimental study

  • Rongjie Pan;Changjiang Liu;Dong Li;Yuanjun Sun;Weibin Huang;Ziye Chen
    • Wind and Structures
    • /
    • 제36권2호
    • /
    • pp.133-147
    • /
    • 2023
  • The random vibration of saddle membrane structures under wind load is studied theoretically and experimentally. First, the nonlinear random vibration differential equations of saddle membrane structures under wind loads are established based on von Karman's large deflection theory, thin shell theory and potential flow theory. The probabilistic density function (PDF) and its corresponding statistical parameters of the displacement response of membrane structure are obtained by using the diffusion process theory and the Fokker Planck Kolmogorov equation method (FPK) to solve the equation. Furthermore, a wind tunnel test is carried out to obtain the displacement time history data of the test model under wind load, and the statistical characteristics of the displacement time history of the prototype model are obtained by similarity theory and probability statistics method. Finally, the rationality of the theoretical model is verified by comparing the experimental model with the theoretical model. The results show that the theoretical model agrees with the experimental model, and the random vibration response can be effectively reduced by increasing the initial pretension force and the rise-span ratio within a certain range. The research methods can provide a theoretical reference for the random vibration of the membrane structure, and also be the foundation of structural reliability of membrane structure based on wind-induced response.

케이블 지지된 풍력발전기 타워 구조 모델의 진동해석 (Vibration Analysis of a Cable Supported Wind Turbine Tower Model)

  • 김석현;박무열;최승훈
    • 산업기술연구
    • /
    • 제27권A호
    • /
    • pp.47-53
    • /
    • 2007
  • A theoretical model based on Rayleigh-Ritz method is proposed to predict the resonance frequency of a W/T(Wind Turbine) tower structure supported by guy cables. In order to verify the validity of the theoretical model, a reduced W/T tower system is manufactured and tested. Frequency response and mode data are determined by modal testing and finite element analysis is performed to calculate the natural frequency of the tower model. Numerical and experimental results are compared with those by the theoretical analysis. Parametric study by the theoretical model shows how the cable tension and cable elasticity influence the resonance frequency of the W/T tower structure. Finally, vibration response under various rotating speed is investigated to examine the possibility of severe resonance.

  • PDF

전완의 등척성 수축시 최대근지구력시간을 예측하기 위한 동적근피로모델의 평가 (Evaluation of dynamic muscle fatigue model to predict maximum endurance time during forearm isometric contraction)

  • 이기영
    • 한국정보전자통신기술학회논문지
    • /
    • 제15권6호
    • /
    • pp.433-439
    • /
    • 2022
  • 최대근지구력시간(MET, maximum endurance time)을 예측하기 위한 근피로모델은 실험적으로 측정한 MET를 이용하여 구축한 실증적 모델과 생리학적 과정을 수학적으로 표현한 이론적 모델로 나뉜다. 본 연구에서는 전완의 등척성 수축시 MET을 예측하기 위한 이론적 모델인 동적 근피로모델의 예측성 평가를 위하여 실증적 모델과 비교 및 평가하고자 한다. 실험에 참여한 피검자는 40명(남성 20, 여성 20)이며 실증적 모델인 지수모델과 거듭제곱모델 및 이론적 모델인 동적 근피로모델을 이용하여 비교하였다. 평가를 위하여 평균절대치편차(MAD, mean absolute deviation), 상관계수 및 급내상관계수를 구한 결과 동적 근피로모델과 실증적 모델들 사이에 MAD는 3.5%p 이하였으며, 상관계수는 0.93, 급내상관계수는 0.87 이상으로 전완의 등척성 수축시 MET을 예측하기 위한 이론적 모델인 동적 근피로모델이 적합함을 확인하였다.

가족 적응력과 가족기능과의 관계 : Olson의 순환모델의 곡선성과 Beavers의 체계모 델의 선형성 (The Comparison of Olson's Circumplex Model and the Beavers' Systems Model in terms of the Relationship between Family Adaptability and Family Function)

  • 장진경
    • 가정과삶의질연구
    • /
    • 제13권4호
    • /
    • pp.1-14
    • /
    • 1995
  • Various theoretical models have developed io both a family research area and family therapy field on he basis of several family theories and social theories in order to understand the family life and its function. These theoretical models have give rise to provide not only a framework for family therapy bt also opportunities for the development of family studies. Regardless of the devotion of these theoretical models to a family therapy however some family therapy professions have suggested the disvergence between these models and practice because the models tend to confuse therapists in their actual practices Other family therapists on the other hand have claimed the convergence between these models and practice. One of the reasons for the issues of convergence and disvergence in the family therapy study would be that various theoretical models have different sometimes contradicatable definitions and explanations for same concept. Therefore the purpose of this paper is to investigate the extent of similarities and differences among these theoretical models of practice in a way of examining family models to compare Olson's circumplex model to the Beavers systems model. Both models were based on the general systems theory. This paper consists of the explanation of Olson's circumplex model and Beavers systems model in general respectively. Then it will investigate similarities and differences between these two models in terms of the relationship between family functioning and family adaptability.

  • PDF

등가 드로우비드 이론 모델 검증 (Verification of Theoretical Model for Equivalent Drawbend)

  • 문성준;금영탁
    • 한국소성가공학회:학술대회논문집
    • /
    • 한국소성가공학회 2008년도 추계학술대회 논문집
    • /
    • pp.367-369
    • /
    • 2008
  • A theoretical model of equivalent drawbead for sheet metal forming analysis is experimentally verified in this paper. After the theoretical drawbead models improved a material description for the accurate calculation of drawbead forces are briefly introduced, they are verified by showing the good agreement of their drawbead forces with experimental measurements. Furthermore, the excellence of theoretical models is demonstrated by the comparison with those of commercial codes.

  • PDF