• Journal of Korean Society for Quality Management
• /
• v.41 no.2
• /
• pp.209-220
• /
• 2013

Purpose: This paper compares and discusses the influence on the quality classification of Kano's questionnaire which is used for the Kano model(Kano et al., 1984), the 3-point Likert-scale newly proposed by Kano and the 5-point Likert-scale presented in this study. Methods: For the comparison, the current study conducts a survey of 631 television viewers. The classification results of the three methods are then compared with those of direct classification which is adopted as a standard for classification of quality attributes. Results: The agreement rates between the results using conventional Kano's questionnaire and the results using direct classification is higher than the results using 3-point and 5-point Likert-scales. In addition, the attributes grouped as must-be or attractive in the direct classification appear to be classified as one-dimensional attributes in the Likert-scales. Conclusion: In comparison with the convensional Kano's questionnaire, the Likert-scale questions highly tend to classify the quatity attributes as one-dimensional. Although the classification results of the 3-point and 5-point Likert-scales are the same, the 5-point Likert-scale has the advantage to classify quality attributes in more detail.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.28 no.3
• /
• pp.279-284
• /
• 2008

The firmness of fruit is one of the most important quality factors and is highly correlated to the elastic modulus. In this study, the ultrasonic transmission method was applied to evaluate the elastic modulus of the apple. In order to transmit and receive the ultrasonic wave through the whole apple, the ultrasonic measurement setup consisted of ultrasonic pulser, two specially fabricated ultrasonic transducers for fruit and digital storage oscilloscope. Ultrasonic parameters such as ultrasonic wave velocity, apparent attenuation, and peak frequencies were analyzed. The elastic modulus of apple was measured by using compression test apparatus. The correlations between ultrasonic parameters and elastic modulus were analyzed. A multiple linear regression model describing the relationship between elastic modulus and ultrasonic parameters was proposed.

• International Commerce and Information Review
• /
• v.11 no.1
• /
• pp.3-25
• /
• 2009

These days international trade has been converting to e-Trade formation. At this point, Korea has been striving for the trade facilitation; reducing logistics cost and improving foreign competitiveness by computerization operations of the maritime transportation that logistics and customs clearance are involved. However, due to the substantial characteristic of logistics service, the necessity of flexible and various logistics service development using internet has been strongly suggested. In particular, the logistics service which could share documents related to international physical movement between shippers and logistics organization. In this regard, this study carried out interview to explore the problems of physical distribution service and to suggest development direction of e-logistics service. The reason why this survey carried out is that most of users want more effective e-logistic service that could diminish successively real expense decrease. After analysis of survey results, this paper presents the basic development direction and emphasis development subjects. Therefore, the basic direction is presented from four viewpoints; customer-oriented approach, service-oriented approach, total approach and step-by-step implementation. Furthermore six development subjects; web-based standard module development for small and medium forwarders, development of standard logistics ERP system, collaboration model between KTNET and KLNET, system improvement for real users, on-demand system building for SMEs and connection with legacy system have been required.

• The Journal of the Acoustical Society of Korea
• /
• v.42 no.2
• /
• pp.143-151
• /
• 2023

In this paper, a method for evaluating the measurement uncertainty is proposed when measuring of floor impact sound insulation of buildings using standard heavy impact source. In addition to the effect of repeated measurements, several other factors such as measurement location, impact location, equipment used for sound pressure measurement, and heavy impact source, were considered. A mathematical model for the average maximum impact sound level and the uncertainty evaluation method for each factor were proposed. The present proposed method was applied to measurement results to evaluate the average maximum impact sound pressure level and the measurement uncertainty.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2005.04a
• /
• pp.89-96
• /
• 2005

Numerical procedure of design optimality evaluation is studied for caisson structural systems. Two kinds of evaluation methods can be considered; mathematical optimality criteria method (MOCM) and numerical optimization method (NOM). The choice of the method depends on the available information of the system MOCM can be used only when the information of all function values, gradients and Lagrange multipliers is available, which may not be realistic in practice. Therefore, in this study, NOMs are applied for the structural optimality evaluation, where only design variables are necessary. To this end, Metropolis genetic algorithm (MGA) is advantageously used and applied for a standard optimization model of caisson composite breakwater. In the numerical example, cost and constraint functions are assumed to be changed from the orignal design situation and their effects are evaluated for optimality. From the theoretical consideration and numerical experience, it is found that the proposed optimality evaluation procedure with MGA-based NOM is efficient and practically applicable.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.19 no.3
• /
• pp.1-14
• /
• 1994

In this paper, an analytical model of the message delay in the DQDB (Distributed Queue Dual Bus) network is investigated. The DQDB network has been adopted as a subnetwork for the IEEE 802 MAN (Metropolitan Area Network) standard. The DQDB network consists of two high speed undirectional buses and a series of stations attached to both of the buses. Massages arriving at each station consists of severla packets according to its size. This system is approximated into " $B^{[x]}$/G/1 with exceptional first service queueing " by defining the concept of service time on a packet. The service time for a packet is defined as the time from the instant the packet arrives at the transmission buffer until the time the packet is fully transmitted. By using the BASTA property and the average work in the system, the mean message delay time is obtained.age work in the system, the mean message delay time is obtained.d.

• ETRI Journal
• /
• v.24 no.5
• /
• pp.391-397
• /
• 2002

This paper presents digital signal processor (DSP) instructions and their data processing unit (DPU) architecture for high-speed fast Fourier transforms (FFTs) in orthogonal frequency division multiplexing (OFDM) systems. The proposed instructions jointly perform new operation flows that are more efficient than the operation flow of the multiply and accumulate (MAC) instruction on which existing DSP chips heavily depend. We further propose a DPU architecture that fully supports the instructions and show that the architecture is two times faster than existing DSP chips for FFTs. We simulated the proposed model with a Verilog HDL, performed a logic synthesis using the 0.35 ${\mu}m$ standard cell library, and then verified the functions thoroughly.

• Journal of the Korean Society for Precision Engineering
• /
• v.32 no.1
• /
• pp.17-24
• /
• 2015

Smart factory requires 4 Zero factors including Zero Waiting-time, Zero Inventory, Zero Defect, Zero Down-time) that needs IT convergence for production resources of 4M1E(Man, Machine, Material, Method, Energy) in real time and event processing in all type of manufacturing enterprises. This paper will be explaining about core emerging production IT convergence technologies including cyber device security, 4M1E integration, real time event driven architecture, common platform of manufacturing standard applications, smart factory to-be model for small and medium manufacturing enterprises.

• Journal of Technologic Dentistry
• /
• v.38 no.3
• /
• pp.185-191
• /
• 2016

Purpose: The purpose of this study were to evaluate the quality of dental prostheses printed by 3-dimensional printing system. Methods: Mater model was prepared and ten study models were fabricated. Ten single crowns were printed by 3D-printing system(Resin group) and another ten single crowns using casting method were manufactured(Metal group). The marginal adaptation of single crowns were measured using by silicone replica technique. Silicone replicas were sectioned four times. The marginal adaptations were evaluated using by digital microscope. Statistical analyses were performed with Mann-Whitney test(${\alpha}=0.05$). Results: $Mean{\pm}standard$ deviations of all marginal adaptations were $92.1(20.0){\mu}m$ for Metal group and $69.7(12.3){\mu}m$ for Resin group. Two groups were no statistically significant differences(p>0.05). Conclusion: Marginal adaptation of single crowns printed by 3D-printing system were ranged within the clinical recommendation.

• The KSFM Journal of Fluid Machinery
• /
• v.7 no.6 s.27
• /
• pp.55-61
• /
• 2004

A numerical procedure for optimizing the shape of three-dimensional sedimentation tank is presented to maximize its sedimentation efficiency. The response surface based optimization is used as an optimization technique with Reynolds-averaged Navier-Stokes analysis for multi-phase flow. Standard $k-{\epsilon}$ model is used as a turbulence closure. Three design variables such as, tank height to center feed wall diameter ratio, blockage ratio of center feed wall and angle of distributor are chosen as design variables. Sedimentation efficiency is defined as an objective function. Full-factorial method is used to determine the training points as a means of design of experiment. Sensitivity of each design variable on the objective function has been evaluated. And, optimal values of the design variables have been obtained.