• 제어로봇시스템학회논문지
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• 제8권10호
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• pp.856-860
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• 2002

The guaranteed stability margin of LQ optimal regulators with cross-product terms in a performance index is derived for the discrete-time case. In order to obtain the guaranteed stability margin, the singular value of the return difference matrix is examined. A numerical simulation is provided to demonstrate the validity of the derived stability margin.

• 한국전기전자재료학회논문지
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• 제19권3호
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• pp.301-306
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• 2006

The electron drift velocity W and the product of the longitudinal diffusion coefficient and the gas number density $ND_{L}$ in the $0.525\;\%$ and $5.05\;\%$ $C_{3}F_8-Ar$ mixtures were measured by using the double shutter drift tube with variable drift distance over the E/N range from 0.03 to 100 Td and gas pressure range from 1 to 915 torr. And we determined the electron collision cross sections set for the $C_{3}F_8$ molecule by STEP 1 of electron swarm method using a multi-term Boltzmann equation analysis. Our special attention in the present study was focused upon the vibrational excitation and new excitations cross sections of the $C_{3}F_8$ molecule.

• 한국경영과학회지
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• 제10권1호
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• pp.65-78
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• 1985

In this paper, the approach getting a total demand by forecasting the new demand and the replacement demand separately and adding them is used for long term forecasting of durable goods. Cross country analysis using the income as an independent variable and S-shaped growth curve as a fitting model is developed as a method of forecasting new demand. To get the replacement demand the methods using the number of ownership and the replacement rate and the methods using the past demand and the distribution of the product life are proposed. And the theoretical explannation for product life cycle's diversity, which is the one of the major considerations in the long term forecasting, is attempted by the combination of the new demand and the replacement demand patterns. This is applicated the long term forecasting of Korean passenger cars.

• 한국정밀공학회지
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• 제16권5호통권98호
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• pp.169-174
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• 1999

In this paper, the CLQR(Constrained LQR) controller, which considers the actuator saturation in a cross-product term of a given performance index for an automotive active suspension control has been proposed. The effects of actuator saturations have been reflected directly in the states by using the linear relation between the control input and states. The method proposed here is more effective and intuitive compared with the conventional schemes. The CLQR has been applied to designing an automotive active suspension control system to verify its effectiveness and practical aspects.

• 응용통계연구
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• 제17권2호
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• pp.229-238
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• 2004

기업의 입장에서 가장 중요한 이유 중 하나는 자사에 있는 많은 고객들 중 회사에 수익을 가져다 줄 수 있는 고객이 누구인가라는 문제이다. 이러한 문제에 대한 기업의 고객 관리 전략 중 하나가 ‘교차판매(cross-sell)’ 전략이다. 본 연구에서는 국내 A손해보험사의 고객 데이터베이스를 활용하여 데이터마이닝 모형 개발이 어떻게 진행되고 있는지 실제 프로젝트를 중심으로 설명하고자 한다. 특히, 본 연구에서 목표로 하고 있는 것은 기존의 자동차보험에 가입한 보험사 고객 중에서 장기보험 및 세부 보험(상해, 질병, 암, 화제 보험 등)에 추가로 가입하는 고객의 특성을 파악하기 위한 교차판매 스코어링 모형을 개발하는 것이다.

• 대한임상검사과학회지
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• 제36권2호
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• pp.121-126
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• 2004

The primary goal of six sigma is to improve patient satisfaction, and thereby profitability, by reducing and eliminating defects. Defects may be related to any aspect of customer satisfaction: high product quality, schedule adherence, cost minimization, process capability indices, defects per unit, and yield. Many six sigma metrics can be mathematically related to the others. Literally, six means six standard deviations from the mean or median value. As applied to quality metrics, the term indicates that failures are at least six standard deviations from the mean or norm. This would mean about 3.4 failures per million opportunities for failure. The objective of six sigma quality is to reduce process output variation so that on a long term basis, which is the customer's aggregate experience with our process over time, this will result in no more than 3.4 defect Parts Per Million(PPM) opportunities (or 3.4 Defects Per Million Opportunities. For a process with only one specification limit (upper or lower), this results in six process standard deviations between the mean of the process and the customer's specification limit (hence, 6 Sigma). The results of applicative six sigma experiment studied on 18 items TP, ALB, T.B, ALP, AST, ALT, CL, CK, LD, K, Na, CRE, BUN, T.C, GLU, AML, CA tests in clinical chemistry were follows. Assessment of process performance fits within six sigma tolerance limits were TP, ALB, T.B, ALP, AST, ALT, CL, CK, LD, K, Na, CRE, BUN, T.C, GLU, AML, CA with 72.2%, items that fit within five sigma limits were total bilirubin, chloride and sodium were 3 sigma. We were sure that the goal of six sigma would reduce test variation in the process.

• 아태비즈니스연구
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• 제10권2호
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• pp.27-41
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• 2019

Following the methodology of Ben-Rephael, Kadan and Wohl (2015), this paper examines whether firm-level liquidity premium exists and whether the premium exhibits a long-term trend in the Korean stock market. The results show that over the whole sample period (1998-2018), a liquidity premium of 0.083% exists in the cross-section of stocks. Interestingly, the pricing of liquidity declines significantly over the sample period. Sub-period analysis indicates that liquidity is priced mainly in the first sub-period (1998-2004) with a significant monthly premium of 0.304%, while the pricing of liquidity becomes weaker or insignificant in the second (2005-2011) and the third (2012-2018) period. I also find that the significance of the liquidity premium in the first period is attributed to small stocks. To explore underlying reasons that might affect the decline in the liquidity premium, I decompose liquidity premium into the product of firm-level liquidity and the sensitivity of expected stock returns on liquidity. The results reveal that the long-term decline is explained by both an increase in firm-level liquidity and a decrease in the sensitivity of expected returns on liquidity.

• Nuclear Engineering and Technology
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• 제54권8호
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• pp.3073-3084
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• 2022

The propagation of radiation source uncertainties in spent nuclear fuel (SNF) cask shielding calculations is presented in this paper. The uncertainty propagation employs the depletion and source term outputs of the deterministic code STREAM as input to the transport simulation of the Monte Carlo (MC) codes MCS and MCNP6. The uncertainties of dose rate coming from two sources: nuclear data and modeling parameters, are quantified. The nuclear data uncertainties are obtained from the stochastic sampling of the cross-section covariance and perturbed fission product yields. Uncertainties induced by perturbed modeling parameters consider the design parameters and operating conditions. Uncertainties coming from the two sources result in perturbed depleted nuclide inventories and radiation source terms which are then propagated to the dose rate on the cask surface. The uncertainty analysis results show that the neutron and secondary photon dose have uncertainties which are dominated by the cross section and modeling parameters, while the fission yields have relatively insignificant effect. Besides, the primary photon dose is mostly influenced by the fission yield and modeling parameters, while the cross-section data have a relatively negligible effect. Moreover, the neutron, secondary photon, and primary photon dose can have uncertainties up to about 13%, 14%, and 6%, respectively.

• Corrosion Science and Technology
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• 제12권1호
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• pp.12-26
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• 2013

This work focused on galvanic corrosion of carbon steel bolted GECM/Al plates by long-term test in tap water and NaCl solutions. Test product was carbon steel bolted between cross packed GECM and painted aluminium. Tests for the product and coupled parts determined corrosion rate in tap water and NaCl solutions. Also, using a potentiostat and salt water sprayer, galvanic test was done. In galvanic test on carbon steel bolted GECM/Al plates, corrosion of carbon steel bolt was faster in series of tap water>1% NaCl solution>3.5% NaCl solution. In galvanic couple between aluminium and carbon steel bolt, their corrosion rates were higher than those of single specimen. In galvanic couple between GECM, aluminium, and carbon steel bolt, corrosion behaviors of carbon steel bolt and aluminium were changed due to different corrosion mechanism in tap water and chloride solution.

• Journal of Radiation Protection and Research
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• 제39권4호
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• pp.176-181
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• 2014

The object of this paper is to evaluate the fission product inventories and radiological doses in a non-LOCA event, based on the U.S. NRC's regulatory methodologies recommended by the TID-14844 and the RG 1.195. For choosing a non-LOCA event, one fuel assembly was assumed to be melted by a channel blockage accident. The Hanul nuclear power reactor unit 6 and the CE $16{\times}16$ fuel assembly were selected as the computational models. The burnup cross section library for depletion calculations was produced using the TRITON module in the SCALE6.1 computer code system. Based on the recently licensed values for fuel enrichment and burnup, the source term calculation was performed using the ORIGEN-ARP module. The fission product inventories released into the environment were obtained with the assumptions of the TID-14844 and the RG 1.195. With two kinds of source terms, the radiological doses of public in normal environment reflecting realistic circumstances were evaluated by applying the average condition of meteorology, inhalation rate, and shielding factor. The statistical analysis was first carried out using consecutive three year-meteorological data measured at the Hanul site. The annual-averaged atmospheric dispersion factors were evaluated at the shortest representative distance of 1,000 m, where the residents are actually able to live from the reactor core, according to the methodology recommended by the RG 1.111. The Korean characteristic-inhalation rate and shielding factor of a building were considered for a series of dose calculations.