• Journal of Distribution Research
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• v.1 no.1
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• pp.239-258
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• 1996

This study deals with the measurement of relational norms, a safeguard for sustained exchange relationshipsim marketing channel systems. Here, the relational norm items are hypothesized to have a second-order factor model, in which mine observed items originate from the three first-order factors and the first order factors in turn originate from a second-order factor. The three first order construe comprising a higher order norm are mutuality(equity in the distribution of benefits and burdens over the course of the exchange on a long term basis), flexibility(expectation of friendly adaption for possible circumstance changes), and solidarity (the degree to which the preservation of the unique and continuing relationship is internalized by the exchange partners as being important in and of itself). 113 research questionnaires are obtained from four industries such as construction, telecommunication, iron, and electric ＆ electronic industries, Reliability and nomological. discriminant validity are tested, and in using the confirmatory factor analysis of Lisrel 7.16, and the chi-square difference test it is tested which has a better satisfactory fit to the data, the first-order model or the second-order one. The results of this study indicates that relational norms have a second order construct. In the electric and electronic industry the model as a while has a satisfactory fit to the data and the relevant first- and second-order factor loading to the mutuality is not significant. Same Results are happened to the flexibility in the telecommunication industry and to the mutuality and flexibility in the inn industry. In sum, the model lends support to our construct, but it is difficult to apply the measurement model to all kinds of industries.

• Journal of Institute of Convergence Technology
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• v.4 no.2
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• pp.17-21
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• 2014

This paper presents the effects of the time delay on the stability of the haptic system that includes a virtual wall and a first-order-hold method. The model of a haptic system includes a haptic device model with a mass and a damper, a virtual wall model, a first-order-hold model and a time delay model. In this paper, the time delay is considered as the computational time delay that is assumed to be as much as the sampling time. As the time delay increases, the maximal available stiffness of a virtual wall model is reduced reversely. The relation among the time delay and the maximum available stiffness, the mass and the damper of the haptic device are analyzed using the MATLAB simulation.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.7 s.262
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• pp.620-627
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• 2007

In this paper, we adapt a modified internal energy non-equilibrium first-order extrapolation thermal boundary condition to the thermal lattice Boltzmann model (TLBM). This model is the double populations approach to simulate hydrodynamic and thermal fields. The bounce-back boundary condition which is a traditional boundary condition of lattice Boltzmann method has only a first order in numerical accuracy at the boundary and numerical instability. A non-equilibrium first-order extrapolation boundary condition has been verified to be of better numerical stability than the bounce-back boundary condition and this boundary condition is proved to be of second-order accuracy for the flat boundaries. The two-dimensional natural convection flow in a square cavity with Pr=0.71 and various Rayleigh numbers are simulated. The results are found to be in good agreement with those of previous studies.

• Food Science and Preservation
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• v.18 no.3
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• pp.423-428
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• 2011

Inactivation kinetic data of Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus, Salmonella Typhimurium, and Salmonella Enteritidis via treatment with aqueous chlorine dioxide treatment at a specific concentration were evaluated using the first-order kinetic and Weibull models. The Weibull model showed a better fit with the kinetic data than the first-order kinetic model. The survival curves after the aqueous chlorine dioxide treatment showed $t_R$ values(time required to reduce microbial populations by 90%) of 2.49 min for E. coli O157:H7 at 5 ppm, 1.47 min for L. monocytogenes at 5 ppm, 0.94 min for S. aureus at 5 ppm, 0.87 min for S. Typhimurium at 1 ppm, and 0.08 min for S. Enteritidis at 1 ppm, according to the Weibull model.

• Journal of Institute of Convergence Technology
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• v.3 no.2
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• pp.23-29
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• 2013

When a human operator interacts with a virtual wall that is modeled as a virtual spring model, the lager the stiffness of the virtual spring is, the more realistic the operator feels that the virtual wall is. In the previous studies, it is shown that the maximum available stiffness of a virtual spring to guarantee the stability can be increased when the first-order-hold method is applied, however the effects of a human impedance on the stability are not considered. This paper presents the effects of a human impedance on stability of haptic system with a virtual spring and a first-order-hold (FOH) method. The human impedance model is modeled as a linear second-order system model. The relations between the maximum available stiffness of a virtual spring and the human impedance such as a mass, a damping and a stiffness are analyzed through the MATLAB simulation. It is shown that the maximum available stiffness is proportional to the square root of the human mass or damping respectively.

• Journal of Institute of Convergence Technology
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• v.5 no.2
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• pp.37-42
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• 2015

This paper presents the effects of the computational time-varying delay on the stability of the haptic system that includes a virtual wall and a first-order-hold method. The model of a haptic system includes a haptic device model with a mass and a damper, a virtual wall model, a first-order-hold model and a computational time-varying delay model. In this paper, the maximum of the computational time-varying delay is assumed to be as much as the sampling time. Using the simulation, it is analyzed how the sample-hold methods and the computational time-varying delay affect the maximum available stiffness. As the maximum of computational time-varying delay increases, the maximal available stiffness of a virtual wall model is reduced.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.6
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• pp.971-979
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• 2011

Palm Oil Mill Effluent (POME) is the mixed organic wastewater generated from palm oil industry. In this study, kinetic analysis with treating POME in an anaerobic hybrid reactor (AHR) was performed. Therefore, the AHR was monitored for its performances with respect to the changes of COD concentrations and hydraulic retention time (HRT). Batch tests were performed to find out the substrate removal kinetics by granular sludge from POME. Modified Stover Kincannon, First-order, Monod, Grau second-order kinetic models were used to analyze the performance of reactor. The results from the batch test indicate that the substrate removal kinetics of granular sludge is corresponds to follow Monod's theory. However, Grau second-order model were the most appropriate models for the continuous test in the AHR. The second order kinetic constant, saturation value constant, maximum substrate removal rate, and first-order kinetic constant were 2.60/day, 41.905 g/L-day, 39.683 g/L-day, and 1.25/day respectively. And the most appropriate model was Grau second-order kinetic model comparing the model prediction values and measured COD concentrations of effluent, whereas modified Stover-Kincannon model showed the lowest correlation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.630-633
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• 2004

Generally, component and FR-4 board are connected by solder joint. Because material properties of components and FR-4 board are different, component and FR-4 board show different coefficients of thermal expansion (CTE) and thus strains in component and board are different when they are heated. That is, the differences in CTE of component and FR-4 board cause the dissimilarity in shear strain and BGA solder joint s failure. The first order Taylor series expansion of the limit state function incorporating with thermal fatigue models is used in order to estimate the failure probability of solder joints under heated condition. A model based on plastic-strain rate such as the Coffin-Manson Fatigue Model is utilized in this study. The effects of random variables such as frequency, maximum temperature, and temperature variations on the failure probability of the BGA solder joint are systematically investigated by using a failure probability model with the first order reliability method(FORM).

• Proceedings of the KIEE Conference
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• summer
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• pp.345-347
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• 2004

In small signal stability analysis of power systems, eigenvalue analysis is the most useful method and the detailed modeling of generator has an important effect to the eigenvalues. Generator full model is used for precise dynamic analysis of generators and controllers while two-axis model is used for multi-machine systems because of the reduced order of the state matrix. Also, the eigenvalue sensitivity coefficients are used for optimizing controller parameters to improve system stability. This paper compare the first and second order eigenvalue sensitivity coefficients of controllers using generator full model with those of two-axis model. As a result of an example, the estimated eigenvalues using the first and the second eigenvalue sensitivity coefficients using generator full model is very close to those of state matrix. Also the error ratios throughout a wide range of controller parameters is less than $1\%$.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.678-683
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• 2008

Moment-based reliability analysis is the method to calculate reliability using Pearson System with first-four raw moments obtained from simulation model. But it is too expensive to calculate first four moments from complicate simulation model. To overcome this drawback the MD(multiplicative decomposition) method which approximates simulation model to kriging metamodel and calculates first four raw moments explicitly with multiplicative decomposition techniques. In general, kriging metamodel is an interpolation model that is decomposed of global model and local model. The global model, in general, can be used as the constant global model, the 1st order global model, or the 2nd order global model. In this paper, the influences of global models on the accuracy and robustness of raw moments are examined and compared. Finally, we suggest the best global model which can provide exact and robust raw moments using MD method.