• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.20 no.42
• /
• pp.131-141
• /
• 1997

The purpose of this study is to certify the actual state of JIT(Just-in-Time) production system's implementation of Korean manufacturing industries and to exhibit the appropriate JIT system considering the company's characteristics, for attain the superior competitiveness. To understand the current situations of JIT system's implementation a questionnaire study is performed. Total 152 valid questionnaires are collected by personal visit and mailing method. All the data is statistically analyzed by SPSS PC+ and SAS program and reviewed to develop a strategy for JIT implementation of Korean manufacturing companies.

• Journal of the Korean Statistical Society
• /
• v.28 no.4
• /
• pp.479-488
• /
• 1999

Moore and Stubblebine(1981) suggested a chi-square test for multivariate normality based on cell counts calculated from the sample Mahalanobis distances. They derived the limiting distribution of the test statistic only when equiprobable cells are employed. Using conditional limit theorems, we derive the limiting distribution of the statistic as well as the asymptotic normality of the cell counts. These distributions are valid even when equiprobable cells are not employed. We finally apply this method to a real data set.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2002.11c
• /
• pp.1915-1918
• /
• 2002

Managing semistructured data needs fine granularity such as markup elements. XML has major effect in managing web content, it enables content reusability, enriches information with metadata, ensures valid document links, etc. We introduce our content model as an integrated work which handles content objects as controllable units. The paper concerns on modeling news site and how the content is classified due to the site structure, aggregated content and reusability. The model stores instance XML document into relation database using fragmentation strategy.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.13 no.3
• /
• pp.213-223
• /
• 2013

A unified channel thermal noise model valid in all operation regions is presented for short channel MOS transistors. It is based on smooth interpolation between weak and strong inversion models and consistent physical model including velocity saturation, channel length modulation, and carrier heating. From testing for noise benchmark and comparing with published noise data, it is shown that the proposed noise model could be useful in simulating the MOSFET channel thermal noise in all operation regions.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.31A no.5
• /
• pp.121-125
• /
• 1994

We examine the conventional method of measuring the internal optical loss using the dependence of the reciprocal external quantum efficiency on the cavity length in laser diodes. It is shown that the implicit assumption of constant internal differential quantum efficiency ${\eta}_{id}$, which has been customarily misinterpreted as internal quantum efficiency ${\eta}_{i}$, is not valid for devices with short cavity length. Therefore, for reliable measurments long cavity data should be used.

• 한국가시화정보학회:학술대회논문집
• /
• 2003.11a
• /
• pp.111-114
• /
• 2003

Drop size is one of the most important parameters which are control the performance of the engine using liquid fuel/oxidizer and drop formation is mainly controlled by aerodynamic force caused by ambient gas. Because of this, empirical data and correlation acquired under standard ambient condition are not valid. So experiments under high ambient pressure condition to measure the drop size using image processing method And find the empirical correlation between SMD and chamber pressure(density), injection velocity.

• Macromolecular Research
• /
• v.10 no.4
• /
• pp.236-239
• /
• 2002

Centrifugation is a method to create functionally graded materials (FGM) with a thermosetting matrix. In this study the movement of short carbon fibers in an epoxy resin during the centrifugation process was modeled to determine the fiber distribution in the final product. For this purpose a form factor K was introduced to modify a set of equations that was previously shown to be valid for the motion of spheres. It was shown that the results of the simulation were in good agreement with the experimental data, when an empirical K factor of four was chosen.

• Proceedings of the Korea Society for Simulation Conference
• /
• 1993.10a
• /
• pp.2-2
• /
• 1993

Inference for discrete event simulations usually relies on either independent replications or, if each simulation run is expensive, the method of batch means applied to a single replications. We present a new method, threshold bootstrap, which equals or exceeds the performance of independent replications or batch means. The method works by resampling runs of data created when a stationary time series crosses a threshold level, such as the sample mean of series. Computational results show that the threshold bootstrap matches or exceeds the performance of these alternative methods in estimating the standard deviation of the sample mean and producing valid confidence intervals.

• Asia pacific journal of information systems
• /
• v.11 no.4
• /
• pp.63-79
• /
• 2001

In this study, we tried to find the factors that influenced appraisal and reward satisfaction in knowledge management, and to observe whether appraisal and reward satisfaction were related to employees' commitment to knowledge management. Analyzing valid 38 data in the organizational level, we found that only result validity and reward justness affected employee appraisal and reward satisfaction. Also, if was found that appraisal and reward satisfaction were related to employees' commitment to knowledge management. The implications of the findings and future research directions were discussed.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.9
• /
• pp.4576-4598
• /
• 2018

In big data age, flexible and affordable cloud storage service greatly enhances productivity for enterprises and individuals, but spontaneously has their outsourced data susceptible to integrity breaches. Provable Data Possession (PDP) as a critical technology, could enable data owners to efficiently verify cloud data integrity, without downloading entire copy. To address challenging integrity problem on multiple clouds for multiple owners, an identity-based batch PDP scheme was presented in ProvSec 2016, which attempted to eliminate public key certificate management issue and reduce computation overheads in a secure and batch method. In this paper, we firstly demonstrate this scheme is insecure so that any clouds who have outsourced data deleted or modified, could efficiently pass integrity verification, simply by utilizing two arbitrary block-tag pairs of one data owner. Specifically, malicious clouds are able to fabricate integrity proofs by 1) universally forging valid tags and 2) recovering data owners' private keys. Secondly, to enhance the security, we propose an improved scheme to withstand these attacks, and prove its security with CDH assumption under random oracle model. Finally, based on simulations and overheads analysis, our batch scheme demonstrates better efficiency compared to an identity based multi-cloud PDP with single owner effort.