• Title/Summary/Keyword: Cause-Effect Model

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Policy Evaluation of the Government Financial Transfers to Korean Fisheries : LISREL Approach (수산부문 정부재정지원정책의 정성 평가)

  • 박성쾌;김정봉
    • The Journal of Fisheries Business Administration
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    • v.33 no.2
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    • pp.1-29
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    • 2002
  • The main objective of this research aims at analyzing efficiency of government financial transfers(GFTs) to the Korean fisheries sector, using the Linear Structural Relations model(i.e., LISERL model) and the field survey data. Most policies of GFTs tend to be implemented to protect industries with weak competitive advantages such as infant and/or primary industries. Specific policy instruments include income transfers, government loans with lower interest rates, taxes and the like. Fishing activities are made at a highly changeable natural environment of the ocean with a great amount of risk and uncertainty. Fishing households make their livelihood under the small-scale fisheries. Such fisheries and fishing households have also a relatively weak market power. Because of these fisheries characteristics most coastal states have adopted a variety of government support programs. However, despite such a huge government support, during the past several decades the world fishing communities have seen a tendency of continuous fishereis resource overexploitation. For this resason there have been hot debates over the government support policies for fisheries through OECD, FAO, WTO, and UNEP. In general, policy evaluations tend to be made on the basis of benefit-cost(B/C) analysis. However, the B/C analysis may produce results quite different from real ones primarily due to many unmeasurable effects. Thus, the authors composed simple questionaires and let fishermen, government officials and academic people answer the questions. The survery was made in several ways such as post-mail and personal/group interviews. In recent years, for analysis of policy performances and effectiveness, the LISREL model has often been used, which consists of structural and measurement eqquations. This model has a good advantage of transforming unobservable variables to observable ones so that it helps construct endogenous cause and effect relationships among relevant variables. The evaluation was done from the two aspects: policy results and policy effectiveness. The policy result evaluation showed that there is a need for improvement for policy problem perception and decision-making process, while the policy effect evaluation suggested that the policy goals were successfully achieved and social justice was improved from the perspective of the entire society as well. However, the research results showed that the GFT policies rendered little contrubtion to narrowing down the gap between GFT beneficiaries and non-beneficiaries incomes.

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Analyzing Common Method Bias of the Korean Empirical Studies on Technology Acceptance Model (한국 TAM 실증연구의 동일방법편의 분석)

  • Baek, Sang-Yong
    • The Journal of Information Systems
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    • v.21 no.1
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    • pp.1-17
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    • 2012
  • Common Method Bias(CMB) may cause the potential inflation of correlations between measures assessed via the same method. The problem of CMB has been well known in behavioral sciences because the survey method with self-reporting is vulnerable to CMB. Thus, the discussion on CMB is still ongoing in the MIS research in US. However, in Korea, the MIS research has never paid attention on the CMB problem. The purpose of this study is to examine the CMB problem in the Korean MIS research. To evaluate the effect of CMB, empirical studies on Technology Acceptance Model(TAM) are selected because (1) TAM is one of the MIS research areas studied intensively, (2) TAM is a theoretical model well supported by the existing empirical studies so that the result of this study would have a great ripple effect when the CMB problem turned out to be serious, (3) CMB is domain-specific. 47 TAM samples (out of 45 studies) from three Korean Journals were selected and the relevant data were collected such as correlation matrixes and the measures of the dependent variable. To find and evaluate the size of CMB, two analytic methods (Marker-Variable Technique and Method-Method Pair Technique) are employed. The result showed that there exists CMB in the Korean studies but the problem is not so serious to distort the empirical testing, compared with that of US studies. However, considering that CMB can contaminate the testing results, Korean MIS researchers should explicitly deal with the problem in designing empirical studies and collecting data.

Analytical Study on Improvement in Load Sharing for Planetary Gear Set using Floating Ring Gear

  • Chung, Woo-Jin;Choi, Kyujeong;Oh, Jooseon;Park, Young-Jun;Lee, Ki-Hun
    • Journal of Biosystems Engineering
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    • v.43 no.4
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    • pp.263-272
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    • 2018
  • Purpose: The load on the planet gear of a planetary gear set is uniformly distributed. However, manufacturing and assembly errors cause uneven load sharing in the planetary gear set. To solve this problem, most studies have suggested applying a floating sun gear to the planetary gear set. However, the effect of the floating ring gear and floating carrier has not been extensively studied. This study aimed to investigate the effect of the floating ring gear. Methods: Two models were developed; one was the fixed ring gear model, and the other was the floating ring gear model. In the fixed ring gear model, the clearance between the ring gear and the housing was $0{\mu}m$, and in the floating ring gear model, the clearance was from $10{\mu}m$ to $100{\mu}m$. The load sharing of the planetary gear set was evaluated by the load sharing factor. Results: Our study showed that with increase in clearance, the load sharing factor of the planetary gear set approached unity. In addition, when the clearance increased above a certain level by which a fully floating ring gear was achieved, the load sharing factor was not affected by the clearance. Conclusions: This indicates that the fully floating ring gear increased the power density of the planetary gearbox by uniformly dividing the load of the planetary gear set. For this reason, the size of the gearbox could be decreased by using a fully floating ring gear.

A Study on the Prediction Model of Shear Strength of RC Beams Strengthened for Shear by FRP (섬유보강재로 전단보강된 RC보의 전단강도예측을 위한 해석모델에 대한 연구)

  • 심종성;오홍섭;유재명
    • Journal of the Korea Concrete Institute
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    • v.12 no.5
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    • pp.35-46
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    • 2000
  • In this paper, an analytical model is proposed to predict the shear strenth of RC beams strengthened by FRP. This predictional model is composed of two basic models-the upper bound theorem for shear failure (shear tension or shear compression criteria) and a truss model based on the lower bound theorem for diagonal tension creteria. Also, a simple flexural theory based on USD is used to explain flexural failure. The major cause of destruction of RC beams shear strengthened by FRP does not lie in FRP fracture but in the loss of load capacity incurred by rip-off failure of shear strengthening material. Since interfacial shear stree between base concrete and the FRP is a major variable in rip-off failure mode, it is carefully analyzed to derive the shear strengthening effect of FRP. The ultimate shear strength and failure mode of RC beams, using different strengthening methods, estimated in this predictional model is then compared with the result derived from destruction experiment of RC beams shear strengthened using FRP. To verify the accuracy and consistency of the analysis, the estimated results using the predictional model are compared with various other experimental results and data from previous publications. The result of this comparative analysis showed that the estimates from the predictional model are in consistency with the experimental results. Therefore, the proposed shear strength predictional model is found to predict with relative accuracy the shear strength and failure mode of RC beams shear strengthened by FRP regardless of strengthening method variable.

The Effect of Flow Distribution on Transient Thermal Behaviour of CDPF during Regeneration (배기의 유속분포가 CDPF의 재생 시 비정상적 열적 거동에 미치는 영향)

  • Jeong, Soo-Jin;Lee, Jeom-Joo;Choi, Chang-Ho
    • Transactions of the Korean Society of Automotive Engineers
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    • v.17 no.2
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    • pp.10-19
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    • 2009
  • The working of diesel particulate filters(DPF) needs to periodically burn soot that has been accumulated during loading of the DPF. The prediction of the relation between an uniformity of gas velocity and soot regeneration efficiency with simulations helps to make design decisions and to shorten the development process. This work presents a comprehensive combined 'DOC+CDPF' model approach. All relevant behaviors of flow fluid are studied in a 3D model. The obtained flow fields in the front of DPF is used for 1D simulation for the prediction of the thermal behavior and regeneration efficiency of CDPF. Validation of the present simulation are performed for the axial and radial direction temperature profile and shows goods agreement with experimental data. The coupled simulation of 3D and 1D shows their impact on the overall regeneration efficiency. It is found that the flow non-uniformity may cause severe radial temperature gradient, resulting in degrading regeneration efficiency.

The Estimation Method of Equipment Maintenance Cost (장비유지비 소요 예측 기법 연구)

  • Kim, Jeong-Ki
    • Journal of the military operations research society of Korea
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    • v.34 no.3
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    • pp.41-51
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    • 2008
  • Advanced high-tech weapons have enormous affect on combat strength in modern warfare. However, lack of maintenance can cause decrease in equipment operating rate as well as decrease in expectation on demonstrative effect of combat strength during wartime. Therefore it is essential for combat readiness that the optimum requirement of equipment maintenance cost are forecasted and included in the budget. In this paper, the trend of equipment maintenance cost about K-111 1/4t military vehicle is first analyzed by evaluating the performance data of field operation. Secondly, based on above analyzed results, the forecasting model of equipment maintenance cost is designed. Finally, by applying this forecasting model, suggestion and estimation method of equipment maintenance cost have presented for the foreseeable future.

Structural Equation Modeling on Burnout in Clinical Nurses based on CS-CF Model (공감만족-공감피로(CS-CF) 모델에 근거한 임상간호사의 소진 구조모형)

  • Kim, Hyun-Jung;Yom, Young-Hee
    • Journal of Korean Academy of Nursing
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    • v.44 no.3
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    • pp.259-269
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    • 2014
  • Purpose: The purpose of this study was to construct and test a structural equation modeling on burnout of clinical nurses based on CS-CF model. Methods: A survey using a structured questionnaire was conducted with 557 clinical nurses. Data were analyzed using structural equation modeling. Results: The modified hypothetical model yielded the following ${\chi}^2=289.70$, p<.001, RMSEA=.09, GFI=.93, TLI=.91, CFI=.94, PCFI=.65, AIC=363.21, SRMR=.05 or less and showed good fit indices. Nursing work environment, patient safety culture and resilience showed indirect effects on burnout while compassion fatigue and compassion satisfaction had direct effects. Conclusion: Results of this study suggest that compassion fatigue must be decreased and compassion satisfaction has to be increased, while burnout is lowered by enhancing the clinical nursing work environment, patient safety culture and resilience. In addition, more variables and longitudinal studies are necessary to validate the clear cause-and-effect relationship between the relevant variables.

A Study on the Design of Flexible Display Considering the Failure Characteristics of ITO Layer (플렉시블 디스플레이에서 ITO층의 파괴 특성을 고려한 설계연구)

  • Kim, Min Gyu;Park, Sang Baek;Chae, Soo-Won
    • Journal of the Korean Society for Precision Engineering
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    • v.30 no.5
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    • pp.552-558
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    • 2013
  • In recent years the interest on flexible display has been increasing as a future display due to its bendable characteristics. An ITO(indium tin oxide) layer, which is part of a flexible display, can be broken easily while bending because it is made of brittle materials. This brittle property can cause the malfunction of flexible display. To analyze fracture characteristics of ITO layer, bending test was conducted commonly. However, it is not possible to know specific phenomena on bended ITO layer by simple bending test only. Accordingly, in this study, the FE(finite element) model is developed similarly to a real flexible display to analyze stress distribution of flexible display under bending condition, especially on ITO layer. To validate FE model, actual bending test was conducted and the test results were compared with the simulation results by measuring reaction forces during bending. By using the developed model, FE analysis about the effect of design parameter (Thickness & Young's Modulus of BL) on ITO Layer was performed. By explained FE analysis above, this research draws a conclusion of reliable design guide of flexible display, especially on ITO layer.

ESTIMATION OF SEU THRESHOLD ENERGY FROM KITSAT-1 DATA USING AP-8 MODEL (AP-8 모델을 이용한 우리별 1호 SEU 문턱에너지 추정)

  • 김성준;신영훈;김성수;민경욱
    • Journal of Astronomy and Space Sciences
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    • v.18 no.2
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    • pp.109-118
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    • 2001
  • KITSAT-1, launched in 1992, passes through Inner Van Allen Radiation Belt in which high energy Protons cause single event upsets(SBUs) in the main memory of KITSAT-1 OBC(On-Board Computer) 186. The present paper compares SEU data from the OBC186 with the AP-8 model of NASA/NSSDC using the Chi-Square method to estimate the SEU threshold energy. Shielding effect by the satellite body has been taken into account to model the proton fluxes at the position of OBC186, and SEUs recorded during the high solar activities have been removed to avoid the spurious result. The result shows that the SEU threshold energy of the main memory of KITSAT-1 OBC186 is estimated to be about $110{pm}10MeV$.

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The Effect of Learning Cycle Model in Solution Concept on the Cognitive Development for Primary Student (용액 개념의 순환학습이 초등학생의 인지수준발달에 미치는 영향)

  • 최영주;김세경;고영신
    • Journal of Korean Elementary Science Education
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    • v.23 no.4
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    • pp.273-278
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    • 2004
  • According to Piaget, children aged 11 are in the middle of concrete operation period and formal operation period. So, it is necessary to adopt the Learning Cycle Model (LCM) which helps students improve their cognitive development. After determining the test for the Science Concept of Matter (SCOM), the experimental group showed higher average than the comparative group in the post-test. In the sound understanding, the experimental group showed higher ratio than the comparative group. And in the ratio of imperfect, wrong understanding and no response, the experimental group was lower than the comparative group. On the questions that were needed the complicated inquiry, many students of both groups still couldn't find the fundamental cause. In forming the scientific conceptualization, there was a meaningful difference (p < .001) after post-test Analysis of Covariance (ANCOVA) with pre-test result. After determining the test for the Test Inquiry Science Process (TISP), the experimental group showed higher average than the comparative group in the post-test. In the category of basic inquiry process which is needed in concrete operation, there was a meaningful difference (p < .05). In the category of unified inquiry process which is needed in formal operation, they showed no meaningful difference (p > .05). Therefore, applying the LCM to the chapter of 'Solution and Dissolving' is more effective on improving the scientific conceptualization and on helping the concrete operation abilities than the teacher centered learning.

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