• Journal of Applied Reliability
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• v.7 no.1
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• pp.13-22
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• 2007

A preventive maintenance model, caller FNBM (${\alpha},{\delta},{\gamma}$) model, is proposed to decide an optimal repair number under achieved availability requirements (r) along with taking two types of failures (repairable or irrepairable) into account. In this model, the current system is replaced by a new one in case when it doesn't meet the achieved availability requirement, even though it is repairable failure; Othewise it is replaced in time of the first irrepairable failure. Assumed that the j-th failure is repairable with probability ${\alpha}_j$ minimal repairs are allowed for repairable failure between replacements. Expected cost rate for preventive maintenance model is developed using NHPP (Non - Homogeneous Poisson Process) in order to de term in the optimal number $n^*$, also numerical examples are shown in order to explain the proposed model. Since the proposed FNBM (${\alpha},{\delta},{\gamma}$) model includes Park FNBM model (1979) and Nakagawa FNBM (p) model (1983) m this proposed model is thought to be better than previous model, especially for weapon system which requires availability as primary parameter.

• Journal of the Korea Society for Simulation
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• v.24 no.3
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• pp.55-60
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• 2015

This paper presents an SBA (simulation-based acquisition) effectiveness analysis environment using the RUP (Relational Unified Process) model. The RUP model has 4 phases which cover the whole development steps such as requirement analysis, design, development and test. By applying the RUP model, SW development can be represented with the iterations of developments for each phase. Such a characteristics of the model would make the model suitable for defense acquisition. In this paper, we show the relation between the RUP model and V process model, which is the foundation for defense acquisition. In order to show how the model could be applied to SBA effectiveness analysis, graphical user interfaces for the analysis are presented at the end of the paper.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.1
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• pp.57-71
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• 2009

Crop-livestock mixed farming systems depend on the efficiency with which nutrients are conserved and recycled. Home-grown forage is used as animal feed and animal excretions are applied to cultivated crop lands as manure. The objective of this study was to develop a mixed farming system model for dairy cattle in Japan. The model consisted of four sub-models: the nutrient requirement model, based on the Japanese Feeding Standards to determine requirements for energy, crude protein, dry matter intake, calcium, phosphorus and vitamin A; the optimum diet formulation model for determining the optimum diets that satisfy nutrient requirements at lowest cost, using linear programming; the herd dynamic model to calculate the numbers of cows in each reproductive cycle; and the whole farm optimization model to evaluate whole farm management from economic and environmental viewpoints and to optimize strategies for the target farm or system. To examine the model' validity, its predictions were compared against best practices for dairy farm management. Sensitivity analyses indicated that higher yielding cows lead to better economic results but higher emvironmental load in dairy cattle systems integrated with forage crop production.

• Journal of Information Technology Applications and Management
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• v.23 no.3
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• pp.71-86
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• 2016

This paper proposes a new software quality model composed of a hierarchy of software quality views and three software quality characteristics models. The software view hierarchy is composed of two levels : end view and means view at the first level, contingency view and intrinsic view as sub-views of means view. Three software quality characteristics models are activity quality characteristics model, contingency quality characteristics model, and intrinsic quality characteristics model, which correspond to end view, contingency view, and intrinsic view respectively. This paper also reclassifies characteristics of ISO/IEC 25000 series SQuaRE's software product quality model according to the proposed software quality model. The results illustrate clearly the shortcomings of SQuaRE's product quality model and how to overcome them. First of all, most of SQuaRE's product characteristics should be redefined and conceptually clarified according to the views on which they are really rested. Much more characteristics should be supplemented too. After that, rigorous empirical researches will become relevant. Causal relationships between activity quality characteristics and characteristics of means view should be empirically researched.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.6 no.3
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• pp.190-196
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• 2006

In this paper, the nonlinear damping force model is made to identify the properties of the ER damper using higher order spectrum. The higher order spectral analysis is used to investigate the nonlinear frequency coupling phenomena with the damping force signal according to the sinusoidal excitation of the damper. Also, this paper presents an inverse model of the ER damper, i.e., the model can predict the required voltage so that the ER damper can produce the desired force for the requirement of vibration control of vehicle suspension systems. The inverse model has been constructed by using piecewise linear damping force model. In this paper, the fuzzy logic control based on heuristic knowledge is combined with the skyhook control. And it is simulated for a quarter car model. The acceleration of the sprung mass is included in the premise part of the fuzzy rules to reduce the vertical acceleration RMS value of the sprung mass. Then scaling factors and membership functions are tuned using genetic algorithm to obtain optimal performance.

• Journal of Korean Institute of Industrial Engineers
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• v.39 no.4
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• pp.247-252
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• 2013

Korea gas corporation (KOGAS) is responsible for the whole sale of natural gas in the domestic market. It is important to forecast the daily demand of city gas for supply and demand control, and delivery management. Since there is the autoregressive characteristic in the daily gas demand, we introduce a modified autoregressive model as the first step. The daily gas demand also has a close connection with the outdoor temperature. Accordingly, our second proposed model is a temperature-based model. Those two models, however, do not meet the requirement for forecasting performances. To produce acceptable forecasting performances, we develop a weighted average model which compounds the autoregressive model and the temperature model. To examine our proposed methods, the forecasting results are provided. We confirm that our method can forecast the daily city gas demand accurately with reasonable performances.

• Fisheries and Aquatic Sciences
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• v.19 no.1
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• pp.4.1-4.7
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• 2016

This study evaluated the dietary lysine requirement by measuring the plasma free lysine concentrations in rainbow trout, Oncorhynchus mykiss after dorsal aorta cannulation. A basal diet containing 36.6 % crude protein (29.6 % crystalline amino acids mixture, 5 % casein and 2 % gelatin) was formulated to one of the seven L-amino acid based diets containing graded levels of lysine (0.72, 1.12, 1.52, 1.92, 2.32, 2.72 or 3.52 % dry diet). A total of 35 fish averaging $512{\pm}6.8g$ ($mean{\pm}SD$) were randomly distributed into seven groups with five fish in each group. After 48 h of feed deprivation, each group of fish was fed one of the experimental diets by intubation at 1 % body weight. Blood samples were taken at 0, 5 and 24 h after intubation. Post-prandial plasma free lysine concentrations (PPlys, 5 h after intubation) of fish fed diets containing ${\geq}2.32%$ lysine were higher than those of fish fed diets containing ${\leq}1.92%$ lysine. Post-absorptive free lysine concentrations (PAlys, 24 h after intubation) of fish fed diets containing 2.32 and 3.52 % lysine were higher than those of fish fed diets containing ${\leq}1.52%$ lysine. The brokenline regression analysis on the basis of PPlys and PAlys indicated that the lysine requirement of rainbow trout could be 2.34 and 2.20 % in diet. Therefore, these results strongly suggested that the dietary lysine requirement based on the broken-line model analyses of PPlys and PAlys could be greater than 2.20 % but less than 2.34 % (corresponding to be $6.01%{\leq},but{\leq}6.39%$ in dietary protein basis, respectively) in rainbow trout. Also, these results shown that the quantitative estimation of lysine requirement by using PPlys and PAlys could be an acceptable method in fish.

• Journal of Animal Science and Technology
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• v.64 no.3
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• pp.471-480
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• 2022

This experiment was conducted to determine the maximum dietary energy levels on growth performance and carcass characteristics of White Pekin duck. the Six dietary treatments were formulated based on their apparent metabolizable energy (AME) concentrations from 2,700 to 3,200 kcal/kg with a 100 kcal/kg gap to evaluate the accurate dietary AME requirement to address current knowledge and further issues for fulfilling the genetic potential of meat-type white Pekin ducklings. A total of 432 one-day-old male White Pekin ducklings were randomly allocated into one of six dietary treatments with six replicates (12 birds per pen). The diets were formulated as corn-soybean meal-based diets to meet or exceed the Nutrient Requirement of Poultry specification for meat-type ducks. Growth performance indices (i.e. average daily gain [ADG], average daily feed intake, feed conversion ratio) were measured weekly. Medium body weight (BW) ducklings from each pen were sacrificed to analyze the carcass traits and abdominal fat content on day 21. Obtained data were analyzed to estimate significant effect using the one-way ANOVA of IBM SPSS Statistics (Version, 25). If the p-value of the results were significant, differences in means among treatments were separated by Tukey's post hoc test. Significant differences were then analyzed with a linear and quadratic broken model to estimate the accurate concentration of AME. Ducklings fed higher dietary AME diets increased (p < 0.05) BW, ADG. Ducklings fed higher AME than 2,900 kcal/kg diets increased abdominal fat accumulation and leg meat portion. The estimated requirement by linear plateau method showed from 3,000.00 kcal/kg to 3,173.03 kcal/kg whereas the requirement by quadratic plateau method indicated from 3,100.00 kcal/kg to 3,306.26 kcal/kg. Collectively, estimated dietary requirements exhibit diverse results based on the measured traits and analysis methods. All the estimated requirements in this experiment present higher than previous research, the maximum requirement for the next diet formulation should be selected by the purpose of the diet.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.215-217
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• 2014

A system architecture design relying only on the experience of its designer varies in quality in line with the designer's personal experience and knowledge ability. Likewise, a wrong estimation of hardware capacity ends up in waste of resources. In practice, a range of post-hoc monitoring tools are in operation, without providing any method for estimating and reflecting the performance at an early stage of architecture design. Provided capacity requirement is estimated in advance with simulation at the stage of design, the system capacity ends up in waste of resources. In practice, a range of post-hoc monitoring tools are in operation, without providing any method for estimating and reflecting the performance at an early stage of architecture design. Provided capacity requirement is estimated in advance with simulation at the stage of design, the system performance requirement can be met with a minimal cost while the waste of resources can be reduced to a great extent. In this context, the present study develops a pilot simulation model for hardware architecture design and then verifies its validity in an experiment. If the error rate falls within a permissible range in the experiment, the simulation model may be considered to reflect well the characteristics of real-life information system architecture.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.6 no.1
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• pp.64-69
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• 2006

Due to the inherent nonlinear nature of Electro-rheological (ER) fluid dampers, one of the challenging aspects for utilizing these devices to achieve high system performance is the development of accurate models and control algorithms that can take advantage of their unique characteristics. In this paper, the nonlinear damping force model is made to identify the properties of the ER damper using higher order spectrum. The higher order spectral analysis is used to investigate the nonlinear frequency coupling phenomena with the damping force signal according to the sinusoidal excitation of the damper. Also, this paper presents an inverse model of the ER damper, i.e., the model can predict the required voltage so that the ER damper can produce the desired force for the requirement of vibration control of vehicle suspension systems. The inverse model is constructed by using a multi-layer perceptron neural network. A quarter-car suspension model is considered in this paper for analysis and simulation. Simulation results show that the proposed inverse model of ER damper can obtain control voltage of ER damper for required damping force.