• Journal of Korean Society for Quality Management
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• v.21 no.2
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• pp.71-84
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• 1993

Currently the problem of air pollution caused by the motor vehicle emission is one of the most serious problems to be solved. Thus we needed the vehicle emissions audit procedure and technical innovation constraining the motor vehicle emission. The Korean Environmental Protection Agency currently audits automobiles for emissions compliance at assembly plants with multiple attribute multiple staged sampling plans. In order to establish the more reasonable audit procedure, the multiple staged sampling plan designed in this paper has been applied to the domestic vehicles by analyzing the statistic characteristics of the emission distribution. This paper summarizes the auditing procedure and develops methods for determining its statistical characteristics. Specifically, we consider how to evaluate a multiple staged sampling plan, give a procedure that efficiently estimates attribute-type probabilities from multivariate variables-type data, and quantify the effect of tightening the acceptable quality level of the sampling plan. As a result it can be proved that this audit procedure is the reasonable plan minimizing the AQL (Acceptable Quality Level) and is to be used effectively for the auditing procedure constraining the injurious gasses of the motor vehicles.

• 한국연소학회:학술대회논문집
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• 2002.11a
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• pp.105-112
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• 2002

The objective of this research is to determine generally applicable design principles for the development of internally staged combustion devices. Utilizing a triple annulus combustor, air staged commercial propane flame configuration are studied. For this triple air staged combustor, the angular momentum weighted by it's swirl number and air distribution ratio was observed to be the critical criteria. An internal recirculation zone which develops on the centerline of the flame immediately downstream of the burner entraps the fuel into a fuel rich eddy. Then sufficient heat must he transferred from the flame via radiation to the chamber heat transfer surfaces, such that when the second air is introduced, peak flame temperatures are suppressed. It is experimentally found out that the total NOx emission level in this type of burner is lower than 0.75g/kg.

• 한국연소학회:학술대회논문집
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• 1999.10a
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• pp.149-154
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• 1999

The influences of air staging on NOx emission and burnout of coal flames were investigated using 1MWth combustion test facility. The experiments showed that variation of overall excess air ratio led to a relatively higher NOx emission level for ${\lambda}=1.2.$ When air staging was applied to the combustion air, it was confirmed that a fuel rich primary combustion zone was established and unburned char was burened completely by mixing with the staged air supplied radially around the flame. The NOx emissions were redued by increasing the staged air flow rate, and staging air was suggested to be more than 40% of the total combustion air for the substantial NOx reduction.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.1
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• pp.32-38
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• 2003

Staged combustion, such as air- and fuel-staging, is a relatively well-known technique fur reduction of NOx emission and used in combination with other techniques nowadays. However, the design variables are still selected depending upon operating conditions. There are many variables tested to investigate the NOx emission characteristics fur changing of fuel or air velocity, swirl intensity, and staging ratio of air and fuel in multi-staged burner. In air-staging case, the fuel-rich condition of the primary combustion zone is very helpful to reduce NOx emission and its range is known to be restricted by the increase of carbon monoxide. However, in many cases carbon monoxide level is not too high to be restricted operating condition. So we tried to expand the equivalence ratio range to the richer condition in the primary combustion zone and certificate the function of each burner component and its contribution to the overall NOx production.

• Journal of Industrial Technology
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• v.24 no.A
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• pp.239-250
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• 2004

Numerical analysis were performed to investigate the stability and internal movement of tunnel located beneath the base of abutment of bridge according to the method of supporting tunnel. Two supporting methods of the multi-staged grouting method with steel pipes and the large diameter of pipe supporting method were used in the centrifuge model tests. The slip form of model lining, specially built to simulate the process of tunnel excavating under the condition of accelerated g-level, was used in the centrifuge model tests. Four centrifuge model tests were performed, changing the supporting methods of the multi-staged grouting method with steel pipes and the large diameter of pipe supporting method and the location of model abutment base of bridge. For internal displacement of tunnel, movements of the crown. The left and the right sides of spring line were measured during the proceeds of excavating tunnel in centrifuge model tests. Test results were compared with numerically estimated values of internal displacement of tunnel by using the commercially available FEM software of PENTAGON-3D. It was found that they were in good agreements and the large diameter of pipe supporting method was more stable than the multi-staged grouting method with steel pipes with respect to the internal movement of tunnel.

• KIPS Transactions on Software and Data Engineering
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• v.8 no.8
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• pp.323-330
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• 2019

In order to improve the level of the IT organization, CMMi played a lot of roles in improving the IT efficiency and quality step by step. In a university organization if you use a customized IT governance framework for the concept of CMMi, it will be a university IT governance to realize the vision of the university. In this paper, we propose Staged Framework for the university developed for applying to university with reference to this staged model of CMMi. The university has applied its own process step by step and it can be uses in the university field. So it can be applied to university IT plan and budget in compliance with not only the person in charge of IT service center but the person in charge of university headquarters. The staged framework is classified into the maturity and process of university IT project and suggests ways to apply it to the improvement of university IT system levels.

• Journal of the Korean Society of Combustion
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• v.8 no.1
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• pp.25-35
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• 2003

The objective of this research is to determine generally applicable design principles for the development of internally staged combustion devices. Utilizing a triple annulus combustor, the detailed combustion characteristics are studied. For this triple air staged combustor, the angular momentum weighted by it#s swirl number and air distribution ratio was observed to be the critical criteria of NOx emission. An internal recirculation zone which develops on the centerline of the flame immediately downstream of the burner entraps the fuel into a fuel rich eddy. Then sufficient heat must be transferred from the flame via radiation to the chamber heat transfer surfaces, such that the peak flame temperatures are suppressed when the second air is introduced. It is experimentally found out that the total NOx emission level in this type of burner is below 50ppm(3% Ref. O2) at optimum operating conditions.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.2021-2034
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• 2008

This paper shows the result of study on the process improvement/innovation based on CMMI(Capability Maturity Model Integration) for Development V1.2 staged representation in the view of engineering area of software, hardware and system. This paper intend to help rolling stock industry to define & innovate process and finally obtain certificate for achievement of CMMI V1.2 from SEI authorized SCAMPI Lead Appraiser through the introduction experienced by Hyundai Rotem Company(car-builder and supplier of electronic & electrical equipment) such as why CMMI-based process definition & improvement are planned and how each processes of CMMI V1.2 Level 3 have been implementing and how obtaining the certificate of CMMI Maturity Level 3 of CMMI for Development V1.2 staged representation etc. This paper shows the introduction to CMMI V1.2 model, process improvement methodology and CMMI appraisal on the basis of Standard $CMMI^{SM}$ Appraisal Method for Process Improvement($SCAMPI^{SM}$), V1.2. And, this paper shows about what kinds of activities/practices of 18 processes(CMMI Maturity Level 3) is essentially implemented to satisfy their's specific goal and general geal through Hyundai Rotem Company's experiences. This paper shows the advantage and problem by adopting CMMI V1.2 model. Especially, it present the corrective/preventive actions against the identified problem in order to improve processes.

• KSBB Journal
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• v.24 no.3
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• pp.303-311
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• 2009

A scaling up study for the exopolysaccharide (EPS) production by submerged culture of Ganoderma lucidum was carried out in jar fermenter systems (2.6, 20 and 75 L) under bi-staged pH process. Profiles of dissolved oxygen (DO) and volumetric coefficient of oxygen transfer ($k_La$) as a function of operating variables (agitation speed and aeration rate) was investigated, and a correlation between $k_La$ and operating variables was analysed statistically. Under bi-staged pH process, no limitation of DO was observed at agitation speeds tested in the range of 200 and 600 rpm, and the highest EPS production was obtained at the level of DO of $40{\sim}80%$. From the regression analysis, the relation between $k_La$, gas velocity (Vs), stirrer speed (N) and impeller diameter (Di) could be expressed as : $$k_La=0.555{\times}Vs^{0.42}{\times}(N^3{\times}Di^2)^{0.33}\;(R^2=0.925,\;p<0.05)$$ It was found that under 2.6 L jar fermenter, the optimum agitation speed and aeration rate was 400 rpm and 1 vvm, respectively, obtaining the EPS production of 15.43 g/L. Under the submerged cultivation of G. lucidum in jar fermenters of $2.6{\sim}75\;L$, the similar EPS yields at each fermenter were achieved during scaling up based on $k_La$, and $k_La$ value for maximum EPS production was $85.4{\pm}26.70\;h^{-1}$.

• Journal of The Korean Association For Science Education
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• v.15 no.1
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• pp.116-125
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• 1995

This study is to consider hypotheses with integral view on the respect of creative thinking. Subjects of this study are Korean students in the 5th grade who participated in the Field Trip Contest of the second Korean Youth Science Festival, an openended inquiry investigation. Objectives of this study are as follows: 1) to measure the inquiry level of the Field Trip Contest activity 2) to find how many hypotheses were made on different types in the inquiry investigation 3) to measure the quality level of hypotheses made in the scientific inquiry investigation 4) to find out the correlation between the 1st and 2nd hypotheses and the final activity score in the two staged scientific investigation In the consequence of it, inquiry level of the Field Trip Contest was very high with good activity topics and openended way of investigation. Hypotheses were made in the prediction, plan, and conclusion parts in the field trip activity report. They used hypothesis-as-prediction typed statements(3.41/team) more than hypothesis-as-explanation(1.28/team) and descriptive hypothesis(0.03/team) types. Content-related hypothesis(5.03/team) and process-related hypothesis(6.16/team) were usually coupled each other. Most of them had difficulties in hypothesis-from-evidence(0.31/team, 10/32 teams) in the comparison of hypothesis-from-simple conjecture(10.62/team). The quality level of content-related hypotheses(0.74point/statement) and process-related hypotheses(1.98point/statement) were very low by the hypothesis-quality scale(Quinn and George, 1975) for the content-related hypotheses and the process-related hypothesis quality scale developed in this study. There was considerable correlation between the activity score and the 1st and 2nd hypothesis in the 2 staged inquiry investigations with the 2nd and 3rd topics($0.41{\ast}$, $0.59{\ast}{\ast}$ repectively).