• Convergence Security Journal
• /
• v.8 no.4
• /
• pp.121-126
• /
• 2008

It is of great practical interest to decide when to stop testing a software system in development phase and transfer it to the user. This decision problem called an optimal release policies. In this paper discussed to specify an optimal release policies. In this paper, propose an optimal release policies of the life distribution applied Erlang distribution of special pattern of Gamma distribution. In this paper, discuss optimal software release policies which minimize a total average software cost of development and maintenance under the constraint of satisfying a software reliability requirement. From Sensitivity Analysis, make out estimating software optimal release time.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1995.04a
• /
• pp.939-954
• /
• 1995

We propose a policy for controlling the release of raw wafers into the semiconductor wafer fabrication lines. The proposed policy exploits up-to-date factory floor information gathered by tracking systems used to calculate the time and amount of a new release to minimize mean flow times and mean tardiness while maintaining the maximum output rates of the system. Extensive computer experiments show that the proposed policy results in significant improvements for the same output rates compared to existing release rules.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.49 no.5
• /
• pp.264-268
• /
• 2000

In discuss how the existing study results that decide optimum release time are rational and reasonable, considering the cost and reliability simultaneously in this paper. As a study method this paper examines the proposed results and their methodologies centering around the existing related papers for the general cost-reliability optimal release policies, especially their limitation for the derived results.

• Journal of Pharmaceutical Investigation
• /
• v.19 no.3
• /
• pp.145-154
• /
• 1989

Methyl methacrylate-butyl methacrylate copolymer (MMBM)-povidone (PVP) films were investigated as a potential topical drug delivery system for the controlled release of econazole nitrate as a model drug. The effect of changes in film composition, drug concentration, film thickness, pH and temperature of release medium on the in vitro release of econazole nitrate were studied. The release rate constant was found to be increased with increasing povidone content in dry films. Drug release followed zero-order kinetics in the initial stage and then release rate increased gradually with time, espicially in the films having larger proportions of PVP. The release rate was found to be dependent on drug content, film thickness, the pH and temperature of release medium. Antimicrobial test showed that microbial growth was inhibited markedly with increasing proportions of PVP in films. Also drug content and film thickness affected the antimicrobial activity.

• Journal of The Korean Society of Integrative Medicine
• /
• v.9 no.2
• /
• pp.35-41
• /
• 2021

Purpose : It is necessary to demonstrate the effect of non-invasive and non-pharmacological interventions such as manual therapy and therapeutic exercise for the management of nonspecific neck pain. In the present study, we aimed to investigate the efficacy of myofascial release therapy plus therapeutic exercise for disability owing to neck pain and quality of life in individuals with nonspecific neck pain. Methods : Eighteen participants with nonspecific neck pain were randomly allocated to intervention (n=9) and control groups (n=9). The intervention group received a myofascial release therapy for 20 min and performed neck stabilization exercises for 30 min twice a week for 4 weeks. The control group performed neck stabilization exercises for 30 min twice a week for 4 weeks at the same time points as the intervention group. Disability owing to neck pain and quality of life were quantified using the neck disability index (NDI) and the Korean version of the World Health Organization Quality of Life Brief Version (WHOQOL-BREF), respectively. NDI and WHOQOL-BREF were assessed before and after intervention. Results : The disability owing to neck pain significantly changed between the groups over time (total score of NDI, p=.049). There were significant time and group interactions in pain (pain intensity of NDI, p=.035) and concentration (concentration of NDI, p=.049). Personal care, lifting, reading, headaches, work, driving, sleeping, and recreation did not show significant improvement between the groups over time. Total score, overall quality of life and general health, physical health domain, psychological domain, social relationships domain, and environmental domain quantified by WHOQOL-BREF did not show significant improvements between the groups over time. Conclusion : These results suggest the clinical use of myofascial release therapy in addition to therapeutic exercise for the management of nonspecific neck pain. Further studies are needed to generalize the findings of this study.

• Journal of the Korean Society of Safety
• /
• v.18 no.1
• /
• pp.64-70
• /
• 2003

For the unconfined vapor cloud explosion(UVCE) accident by the continuous release of gas-liquid flow of various saturated liquids in a vessel at ground level, overpressures were estimated by TNT equivalency model with two estimation methods, such as UVCE I model based on a constant release time and UVCEII model based on a real travel time of vapor by dispersion and analyzed with various release conditions. As a simulation result the simple, easy, and correct method of evaluation of consequences of the UVCE accident was proposed by using consequences of UVCE I model and correlation equations for differences of overpressures between UVCE models, so that this evaluation method could be used easily in the small and medium size enterprises without using the dispersion model.

• Journal of Mechanical Science and Technology
• /
• v.16 no.6
• /
• pp.829-838
• /
• 2002

A constant volume combustion chamber is used to investigate the flame kernel development of gasoline air mixtures under various ignition systems, ignition energies and spark plugs. Three kinds of ignition systems are designed and assembled, and the ignition energy is controlled by the variation of the dwell time. Several kinds of spark plugs are also tested. The velocity of flame propagation is measured by a laser deflection method, and the combustion pressure is analyzed by the heat release rate and the mass fraction burnt. The results represent that as the ignition energy is increased by enlarging either dwell time or spark plug gap, the heat release rate and the mass fraction burnt are increased. The electrodes materials and shapes influence the flame kernel development by changing he transfer efficiency of electrical energy to chemical energy. The diameter of electrodes also influences the heat release rate and the burnt mass fraction.

• 연구논문집
• /
• s.29
• /
• pp.49-55
• /
• 1999

Heat release rate used to characterize the fire is an important factor for determining the fire size, the fire growth and the time for suppression and evacuation. The purpose of present work is to review theoretical backgrounds and to introduce equations for estimation of heat release rate with oxygen consumption method in fires. Our work also shows the experimental results of applications for liquid fuels. The oxygen concentration is measured by the analyzer of paramagnetic type. The analyzers of Infra-Red type are used to measure the concentrations of $CO_2$ and CO gas. Time delays of analyzers are ignored.

• Proceedings of the Korean Reliability Society Conference
• /
• 2002.06a
• /
• pp.273-273
• /
• 2002

In this paper, we investigate a software release policy with software reliability growth factor during the warranty period by assuming that the software reliability growth is assumed to occur after the testing phase with probability p and the software reliability growth is not assumed to occur after the testing phase with probability 1-p. The optimal release policy to minimize the expected total software cost is discussed. Numerical examples are shown to illustrate the results of the optimal policy. And we consider a Bayesian decision theoretic approach to determine an optimal software release policy. This approach enables us to update our uncertainty when determining optimal software release time, When the failure time is Weibull distribution with uncertain parameters, a bayesian approach is established. Finally, numerical examples are presented for illustrative propose.

• Archives of Pharmacal Research
• /
• v.9 no.1
• /
• pp.39-43
• /
• 1986

Bovine serum albumin microspheres containing cytarabine were prepared using cross-linking agent, formaldehyde. The shape and the size distribution of them were observed. The shape of them was spherical and the susrface was compact and smooth. The size distribution of them was affected by dispersion forces during emulsfication. The release of cytarabine from albumin microspheres was dependent upon cross-linking time, amount of cross-linking agent and drug/albumin ratio. However, the difference of drug release by the dispersion forces was not great. After release test, the shape of albumin microspheres was nonspherical and the albumin matrix seemed to be a little relaxed. The degradation tests of albumin microspheres by the proteolytic enzyme showed that albumin microspheres were progressively digested according to the cross-linking degree.