• Analytical Science and Technology
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• v.34 no.6
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• pp.241-250
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• 2021

Calibration curves are essential in quantitative methods and for improving the accuracy of analyte measurements in biological samples. In this study, a statistical analysis model built in the R language (The R Foundation for Statistical Computing) was used to identify a set of weighting factors and regression models based on a stepwise selection criteria. An LC-MS/MS method was used to detect the presence of urinary methamphetamine, amphetamine, and 11-nor-9-carboxy-Δ⁹ -tetrahydrocannabinol in a sample set. Weighting factors for the calibration curves were derived by calculating the heteroscedasticity of the measurements, where the presence of heteroscedasticity was determined via variance tests. The optimal regression model and weighting factor were chosen according to the sum of the absolute percentage relative error. Subsequently, the order of the regression model was calculated using a partial variance test. The proposed statistical analysis tool facilitated selection of the optimal calibration model and detection of methamphetamine, amphetamine, and 11-nor-9-carboxy-Δ⁹-tetrahydrocannabinol in urine. Thus, this study for the selection of weighting and the use of a complex regression equation may provide insights for linear and quadratic regressions in analytical and bioanalytical measurements.

• Journal of computational fluids engineering
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• v.13 no.2
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• pp.62-67
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• 2008

This study aims to investigate numerically the static stiffness characteristics of porous air bearing and to estimate appropriate permeability values of porous medium. In particular, a new roughness model is proposed and implemented into the commercial CFD code (FLUENT Ver. 6.2) by using C language based user subroutine. The predicted results are extensively compared with experimental data. The roughness model is also validated through comparison with the results from open literature. It is found that the predictions for static stiffness are in good agreement with experimental data. Therefore, the suggested model based on the roughness Reynolds number can be used in studying the stiffness characteristics of porous air bearing effectively. In addition, numerical simulations of various diameter size and conditions are conducted. According the results, it is expected that the static stiffness of porous air bearing has the non-linear characteristics.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.11a
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• pp.45-53
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• 2001

Copper bus-bar is made by drawing process and used in many part of industry. When design drawing die for copper bus-bar, design factor is focused on the deformation of die-land by drawing force and shrink fit. In this paper, to determine shrink fit value is analyzed by automatic shrink fit analysis program, APDL/UIDL language in a commercial FEM package, ANSYS, has been developed that enables optimal design of the dies taking into account the elastic deflections generated in shrink fitting the die inserts and that caused by the stresses generated in the process and by using DEFORM software for drawing process analysis. This data can be processed as load input data for a finite element die-stress analysis. Process simulation and stress analysis are thus combined during the drawing die design. The stress analysis of the dies is used to determine optimized dimension of die-land.

• 한국디지털정책학회:학술대회논문집
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• 2004.11a
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• pp.435-448
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• 2004

While Internet promises ubiquitous access, it also creates a fundamental challenge to the traditional ownership toward digital assets traded in e-commerce market. Sharing digital information freely through shared networks leads to many untapped business opportunities, but uncontrolled digital asset transaction undermines many electronic business models. Thus, in this Internet age, proper protection and safe delivery of Intellectual Property (IP) and its representation as digital assets would be a crucial ingredient of building trust in upcoming e-business environment. In this paper, we give a general structural diagram of Intellectual Property Management and Protection (IPMP) and implement an IPMP prototype based on the RSA encryption algorithm and XrML (eXtensible rights Markup Language) WORK tags to show how proper protection and safe delivery of the intellectual property is achieved. This study concludes that IPMP mechanism may contribute significantly to the volume and quality of e-commerce market.

• Speech Sciences
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• v.9 no.1
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• pp.77-88
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• 2002

Acoustical correlates of stress can be classified as duration, intensity and fundamental frequency. This study examined the acoustical differences in the first two syllables of stressed English words produced by ten American and Korean speakers. The Korean subjects scored very high on the TOEFL. They read at a normal speed a fable from which the acoustical parameters of eight words were analyzed. In order to make the data comparison meaningful, each parameter was collected at 100 dynamic time points proportional to the total duration of the two syllables. Then the ratio of the parameter sum of the first rime to that of the second rime was calculated to determine the relative prominence of the syllables. Results showed that the durations of the first two syllables were almost comparable between the Americans and Koreans. However, statistically significant differences showed up in the diphthong pronunciations and in the words with the second syllable stressed. Also, remarkably high r-squared values were found between pairs of the three acoustical parameters, which suggests that either one or a combination of two or more parameters may account for the prominence of a syllable within a word.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.203-206
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• 2005

This paper presents a design experience of supervisory control system for agile and intelligent manufacturing(AIM). For effectively program job instructions, a Petri net-type graphical language is proposed and it can be applied to a various task such as concurrency and synchronization. PGL is consisted of PGL editor, PGL analyzer and PGL translator; PGL editor generates a job instruction program using graphic symbol. PGL analyzer prevents a deadlock or resource allocation of unit cell. PGL translator transfers to adequate sequential job commands of each unit cell.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.473-474
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• 2011

IEC-61850 기반의 디지털 변전소 자동화시스템을 구축하기 위해서는 전체 변전소의 네트워크 구성 정보와 개별 IED들의 정보를 연계 처리할 엔지니어링 툴이 필요하다. 상위 시스템 벤더에 따른 개별적인 SCL(Substation Configuration Description Language) 엔지니어링 툴이 아닌 표준화된 기능들을 갖는 범용툴의 적용은 향후 디지털 변전소자동화 시스템의 필수 요소라 하겠다. 본 논문에서는 실제 변전소에 적용했던 SCL 엔지니어링 툴을 기반으로 필수적인 사항들에 대한 조건을 제시하였고, 복수의 IED의 ICD파일 정보와 전체 변전소 시스템에서 적용되는 정보를 처리하고 기존 SCADA와의 호환성을 위한 기능도 적용하였다. 다양한 전력시스템 벤더들에 따른 개별적인 엔지니어링 툴이 아닌 IEC-61850 프로토콜 표준이 적용된 디지털 변전소에 적합한 효율적인 SCL 엔지니어링 툴의 표준을 만드는데 도움이 되고자 한다.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.330-335
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• 2001

Characteristics of the present world market include demanding and sophisticated customers, requirement of high quality and innovative products, greater product diversity, increasing labour and products costs, availability of diverse alternatives to the customers and smaller batch sizes to satisfy a variety of customer profiles. To fulfil these characteristics, manufacturing companies need to be flexible adaptable, proactive and able to produce variety of products in short time at low cost. The aim of the study is to develop a computer-aided design system for water-gate on AutoCAD R2000 system. The developed system has been written in AutoCAD and VisualLISP with a personal computer, and is composed four modules which are the gate-lifter input module, guide-frame input module, and upgrade module. Based on knowledge-based rules, the system is designed by considering several factors, such as width and height of a water-gate, material, object of product and maximum depth of water.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1033-1037
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• 1987

This paper proposes a basic implementation of bi-directional transition system between Korean and Japanese. The syntactic structure of Korean language is very similar to that of Japanese. In order to use the same main program for bi-directional translation, system is classified into two parts. One is directly translatable part and the other is untranslatable part by direct matching because of different structure. Solving these problems, the syntactic and semantic informations control bi-directional interpreting process and make equivalent syntactic level between two languages.

• English Language & Literature Teaching
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• no.4
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• pp.179-206
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• 1998

Despite the fact that the phenomenal success of the classical model in phonology in terms of a small set of binary atomic primitives has encouraged the use of criterical features in the characterization of syntactic and semantic categories, cognitive linguists have recently found many evidences against it and proposed a valid alternative like prototype approach to classical model of linguistic categorization. In this paper the examples with prototype effects are shown in phonology, morphology, and syntax. In phonology there is no clear-cut borderline in initial sounds such as / r, m, n, v, ${\eth}$, z, w. j, b. d, g / and between vowels and consonants. In morphology family resemblance is shown between strong verbs and past tenses. In syntax there is no borderline among various kinds of sentences such as declarative, command, WH-question, yes-no question, etc.