• 제어로봇시스템학회:학술대회논문집
• /
• 2001.10a
• /
• pp.163.3-163
• /
• 2001

This paper presents the two-step strategy method of performing optimal scheduling of paper mill processes using MINLP (Mixed-Integer Non-Linear Programming) considering the trim loss problem in sheet cutting processes. The mathematical model for a sheet cutting process in the form of MINLP is developed in this study, and minimizing total cost is performed considering the cost of raw paper roll, :hanging cutting patterns, storage of over-product and recycling/burning trim. The paper has been used to deliver and conserve information for a long time, and it is needed to have various sizes and weights ...

• Journal of the Korean Statistical Society
• /
• v.3 no.1
• /
• pp.17-30
• /
• 1974

There are a number of studies on the peculiarities of inflation in underdeveloped economies. These studies are, however, confined to the cases of Latin American countries, and the essence of methodologies applied in the studies is basically estimations of linear parameters of an extended quantity equation with lagged variables. As it is generally observed, inflation in most of underdeveloped economies are, to some extent, affected by non-economic factors such as political instability, social disorder, abrupt institutional changes, etc. Sometimes, these factors underlying the basic movement of price level change are reflected in such variables as quantity of money supply, income velocity, gross national product.

• The Journal of Asian Finance, Economics and Business
• /
• v.8 no.2
• /
• pp.1017-1023
• /
• 2021

This research aims to determine the effect of customers' threat emotion and price on the decision to purchase a certain smartphone product. This study uses a quantitative method with a type of descriptive and causal research. It employs non-probability sampling with purposive sampling, with 385 respondents to answer the questionnaires. Data analysis techniques used descriptive analysis and multiple linear regression analysis. Based on the results of descriptive analysis of emotion, price and purchasing decisions are in sync with each other. The results of multiple linear regression analysis techniques indicate the threat emotion and brand trust are influential against the positive decision to purchase smartphone products. The magnitude of the influence of emotions and price have simultaneous effect on purchasing decisions and other decision variables, which are not included in this study, also play minor role in determining purchase intention, such as product quality, brand image and others. Partially, threat emotion and brand trust have a positive effect toward purchasing decisions. The magnitude of the highest influence was the one of price, then followed by emotional threats. The findings of this study suggest that psychological and behavioral effects also play important roles in determining customers' purchase decision.

• Journal of Korean Society for Quality Management
• /
• v.43 no.3
• /
• pp.373-382
• /
• 2015

Purpose: In this paper, we developed a reliability index (RI) to efficiently compare reliability of products based on the design, development and production information such as reliability tests, quality, product life-cycle management. RI also can be applied to reliability prediction of a novel product as well as comparison evaluation among existing products. Methods: For evaluating RI, we proposed evaluation process which is composed of five steps. Target modules are selected based on warranty data and correlation analysis. Scores of selected target modules are calculated by scoring function. Finally, weights of RI model are determined by optimization method. Results: This paper presented an empirical analysis based on failure data of mobile devices. In this case study, we demonstrated that there is a direct correlation between evaluated RI and field failure probability of each product. Conclusion: We proposed the index for comprehensive and effective assessment of product reliability level. From the procedure of this study, we expected to be applied for reliability estimation of novel products and deduction of field failure-related factors.

• Asia-Pacific Journal of Business
• /
• v.12 no.1
• /
• pp.87-100
• /
• 2021

Purpose - This study aims to examine the antecedents of willingness to pay in the domain of duty free shop. Design/methodology/approach - This study chooses willingness to pay as explained variable. The candidates of explanatory variables are price fairness, brand awareness, employee service, product diversity, and crowding. This study uses survey to explore the linear relation between variables. This research collected data using online panel data collection service. The number of valid observation is 265. The research targe is Lotte duty free store. Statistical analysis was for statistical inference. To attain the information of survey respondents, frequency analysis is employed. Next, this study implemented exploratory factor analysis and reliability to ensure both validity and reliability of measurement items. This study executed multiple regression analysis to test research hypotheses Findings - Regrading results, brand awareness, employee service, and product diversity are positively associated with willingness to pay of duty free shop product. Moreover, the results of regression analysis suggest the inverted-U shape association between crowding and willingness to pay. However, price fairness appeared as non-significant variable to account for willingness to pay in the multiple regression analysis. Originality - This study contributes to the literature by examining duty free shop customers more.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.6
• /
• pp.157-165
• /
• 2016

Among high-tech products, the mobile phone has experienced a rapid rate of innovation and a shortening of its product life cycle. The shortened product life cycle poses major challenges to those involved in the creation of forecasting methods fundamental to strategic management and planning systems. This study examined whether the best model applies to the entire diffusion life span of a mobile phone. Mobile phone sales data from a specific mobile service provider in Korea from March of 2013 to August of 2014 were analyzed to compare the performance of two S-shaped diffusion models and two non-linear regression models, the Gompertz, logistic, Michaelis-Menten, and logarithmic models. The experimental results indicated that the logistic model outperforms the other three models over the fitted region of the diffusion. For forecasting, the logistic model outperformed the Gompertz model for the period prior to diffusion saturation, whereas the Gompertz model was superior after saturation approaches. This analysis may help those estimate the potential mobile phone market size and perform inventory and order management of mobile phones.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.6 no.6
• /
• pp.536-541
• /
• 2005

Large displacement and rigidity about rubber component are expected by nonlinear and large deformation analysis in this study. Rubber is also used by the model of Mooney-Rivlin and the self contact between rubbers is established. There is the friction between rigid body and rubber, wall and floor. The nonlinear simulation analysis used in this study is expected to be widely applied in design, analysis and development of several rubber components which are used in automotive, railroad, and mechanical elements etc. By utilizing this method, time and cost can also be saved in developing new rubber product. The analysis of rubber components requires special material modeling and non-linear finite element analysis tools that are quite different from those used for metallic parts. The objective of this study is to analyze the rubber component with large deformation and non-linear properties.

• Journal of Korean Port Research
• /
• v.12 no.1
• /
• pp.75-86
• /
• 1998

To design a coastal structure in the nearshore region, engineers must have means to estimate wave climate. Waves, approaching the surf zone from offshore, experience changes caused by combined effects of bathymetric variations, interference of man-made structure, and nonlinear interactions among wave trains. This paper has attempted to find out the effects of two of the more subtle phenomena involving nonlinear shallow water waves, amplitude dispersion and secondary wave generation. Boussinesq-type equations can be used to model the nonlinear transformation of surface waves in shallow water due to effect of shoaling, refraction, diffraction, and reflection. In this paper, generalized Boussinesq equations under the complex bottom condition is derived using the depth averaged velocity with the series expansion of the velocity potential as a product of powers of the depth of flow. A time stepping finite difference method is used to solve the derived equation. Numerical results are compared to hydraulic model results. The result with the non-linear dispersive wave equation can describe an interesting transformation a sinusoidal wave to one with a cnoidal aspect of a rapid degradation into modulated high frequency waves and transient secondary waves in an intermediate region. The amplitude dispersion of the primary wave crest results in a convex wave front after passing through the shoal and the secondary waves generated by the shoal diffracted in a radial manner into surrounding waters.

• Industrial Engineering and Management Systems
• /
• v.2 no.1
• /
• pp.35-44
• /
• 2003

Recovery of end-of-life (EOL) products is an environmentally and economically sound way to achieve many of the goals of sustainable development. Many product recovery systems are dependent upon destructive disassembly such as shredding, which undesirably causes a large volume of shredder dust and makes parts reuse impossible. Although non-destructive disassembly has been considered as an alternative for solving the problems, the classification of disassembled items has not been sufficiently investigated. In this paper, we propose a model that mathematically optimizes the disassembly and classification of EOL products. Based on the AND/OR graph that illustrates all possible disassembly sequences of a given product, we identify the physical properties that are considered as constraints in the model. As a result of the solution procedure, the recovery problem can be transformed into a mixed integer linear programming (MILP) model. We show an example that illustrates the concept of our model.

• Structural Engineering and Mechanics
• /
• v.32 no.1
• /
• pp.179-191
• /
• 2009

A stochastic response spectrum method is proposed for simple evaluation of the structural response of an actively controlled aseismic structure. The response spectrum is constructed assuming a linear structure with an active mass damper (AMD) system, and an earthquake wave model given by the product of a non-stationary envelope function and a stationary Gaussian random process with Kanai-Tajimi power spectral density. The control design is executed using a linear quadratic Gaussian control strategy for an enlarged state space system, and the response amplification factor is given by the combination of the obtained statistical response values and extreme value theory. The response spectrum thus produced can be used for simple dynamical analyses. The response factors obtained by this method for a multi-degree-of-freedom structure are shown to be comparable with those determined by numerical simulations, demonstrating the validity and utility of the proposed technique as a simple design tool. This method is expected to be useful for engineers in the initial design stage for structures with active aseismic control.