• Title/Summary/Keyword: Unit Process

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ROBUST UNIT ROOT TESTS FOR SEASONAL AUTOREGRESSIVE PROCESS

  • Oh, Yu-Jin;So, Beong-Soo
    • Proceedings of the Korean Statistical Society Conference
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    • 2003.05a
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    • pp.281-286
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    • 2003
  • The stationarity is one of the most important properties of a time series. We propose robust sign tests for seasonal autoregressive process to determine whether or not a time series is stationary. The tests have an exact binomial null distribution and are robust to the outliers and the heteroscedastic errors. Monte-Carlo simulation shows that the sign test is locally more powerful than the OLSE-based tests for heavy-tailed and/or heteroscedastic error distributions.

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A Unit Root Test Based on Bootstrapping

  • Shin, Key-Il;Kang, Hee-Jeong
    • Communications for Statistical Applications and Methods
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    • v.3 no.1
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    • pp.257-265
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    • 1996
  • We consider nonstationary autoregressive autoregressive process with infinite variance of error. In the case of infinite cariance, the limiting distribution of the estimated coefficient is different from that under the finite cariance assumption. In this paper we show that the bootstrap method can be used to approximate the distribution of ordinary least squares estimator of the coefficient in the first order random walk process with infinite variance through some empirical studies and we suggest a test procedure based on bootstrap method for the unit root test.

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A Study on the Use of Process Drama to Improve Korean Speaking Ability: Focusing on a Unit Design of Sejong Intermediate Korean Conversation Coursebook (한국어 말하기 능력 향상을 위한 과정극(process drama) 활용에 대한 고찰 -'세종한국어 회화 중급' 교재의 과제 단원 개발을 중심으로-)

  • Lee, Junghee;Park, Hae-ok
    • Journal of Korean language education
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    • v.29 no.1
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    • pp.199-222
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    • 2018
  • This study attempts to apply process drama in teaching Korean speaking. For that goal, the first part of the study introduces the main features of process drama exploring the possible use of teaching Korean speaking, and the second part presents a concrete example of developing a unit of the Sejong intermediate Korean conversation coursebook which was designed using a process drama method. Process drama is a process-oriented drama activity which progresses only with the teacher and students' spontaneous participation. With its unique meaning-oriented interaction paradigm, it has been suggested as an effective way of teaching and learning a foreign language. Since it emphasizes students' spontaneity, cooperation, and authentic communication, it commonly provides plenty of opportunities for students to interact in a meaningful context. Despite its effectiveness in teaching speaking, it has rarely been used in KFL contexts. Considering the limited opportunities to practice speaking in KFL classrooms, using a communication-rich activity such as process drama would be an optimal solution. This study, therefore, examines possible application of process drama in teaching Korean speaking, and introduces sample speaking materials designed for KFL intermediate learners.

Study on Chemical Decontamination Process Based on Permanganic Acid-Oxalic Acid to Remove Oxide Layer Deposited in Primary System of Nuclear Power Plant (계통 내 침적된 산화막 제거를 위한 과망간산/옥살산 기반의 화학제염 공정연구)

  • Kim, Chorong;Kim, Haksoo
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.17 no.1
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    • pp.15-28
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    • 2019
  • In accordance with the decommissioning plan for the Kori Unit 1 NPP, the reactor coolant system will be chemically decontaminated as soon as possible after permanent shutdown. This study developed the chemical decontamination process though the development project of decontamination technology of reactor coolant system and dismantled equipment for NPP decommissioning, which has been carried out since 2014. In this study, Oxidation/reduction process was conducted using system decontamination process development equipment of lab scale and was divided into unit and continuous processes. The optimal process time was derived from the unit process, and decontamination agent and the number of process were derived through the continuous processes. Through the unit process, the oxidation process took 5 hours and the reduction process took 4 hours. As optimum decontamination agent, the oxidizing agent was $200mg{\cdot}L^{-1}$ Permanganic acid + $200mg{\cdot}L^{-1}$ Nitric acid and the reducing agent was $2000mg{\cdot}L^{-1}$ Oxalic acid. In the case of the number of processes, all oxide films were removed during the two-cycle chemical decontamination process of STS304 and SA508. In the case of Alloy600, all oxide films were removed when chemical decontamination was performed for three cycles or more.

Development of A Validation System For Automatic Radiopharmaceutical Synthesis Process Using Network Modeling (방사성의약품 합성 프로세스 검증을 위한 네트워크 모델링)

  • Lee, Cheol-Soo;Heo, Eun-Young;Kim, Jong-Min;Kim, Dong-Soo
    • IE interfaces
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    • v.24 no.3
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    • pp.187-195
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    • 2011
  • The automatic radiopharmaceutical module consists of several 2-way valves, couple of syringes, gas supply unit, heating(cooling) unit and sensors to control the chemical reagents as well as to help the chemical reaction. In order to control the actuators of radiopharmaceutical module, the process is tabulated using spread sheet as like excel. Unlike the common program, a trivial error is too critical to allowed in the process because the error can lead to leak the radioactive reagent and to cause the synthesis equipment failure during synthesizing. Hence, the synthesis process has been validated using graphic simulation while the operator checks the whole process visually and undergoes trial and error. The verification of the synthesis process takes a long time and has a difficulty in finding the error. This study presents a methodology to verify the process algebraically while the radiopharmaceutical module is converted to the network model. The proposed method is validated using actual synthesis process.

Design and operating parameters of multi-functional floating island determined by basic experiments of unit processes (단위공정별 기초실험을 통한 다기능 융복합부도의 설계·운전인자 도출)

  • Lim, Hyun-Man;Jang, Yeo-Ju;Jung, Jin-Hong;Yoon, Young-Han;Park, Jae-Roh;Kim, Weon-Jae
    • Journal of Korean Society of Water and Wastewater
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    • v.32 no.6
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    • pp.487-497
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    • 2018
  • Water quality improvement processes for stagnant area consist mainly of technologies applying vegetation and artificial water circulation, and these existing technologies have some limits to handle pollution loads effectively. To improve the purification efficiency, eco-friendly technologies should be developed that can reinforce self-purification functions. In this study, a multi-functional floating island combined with physical chemical biological functions ((1) flotation and oxidization using microbubbles, (2) vegetation purification and (3) bio-filtration with improved adsorption capacity) has been developed and basic experiments were performed to determine the optimal combination conditions for each unit process. It has been shown that it is desirable to operate the microbubble unit process under conditions greater than $3.5kgf/cm^2$. In vegetation purification unit process, Yellow Iris (Iris pseudacorus) was suggested to be suitable considering water quality, landscape improvement and maintenance. When granular red-mud was applied to the bio-filtration unit process, it was found that T-P removal efficiency was good and its value was also stable for various linear velocity conditions. The appropriate thickness of filter media was suggested between 30 and 45 cm. In this study, the optimal design and operating parameters of the multi-functional floating island have been presented based on the results of the basic experiments of each unit process.

Comparative LCA(life cycle assessment) between two different model of Electric Motor Unit(EMU) (서로다른모델의 전동차에 대한 비교 전과정평가)

  • Kim, Jin-Yong;Choi, Yo-Han;Kim, Young-Ki;Lee, Kun-Mo
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.6-14
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    • 2007
  • The objective of this research is to comparative LCA(life cycle assessment) between two different model of Electric Motor Unit(EMU).the environmental impact of Aluminum body Electric Motor Unit(EMU) and Stainless Steel(STS) body Electric Motor Unit(EMU). LCA process consists of four steps which are goal, scope definition, life cycle impact analysis(LCIA) and life cycle interpretation. ISO 14044 provides the LCA standard method which can be conducted by using comparative LCA. From the research it is foung that the Aluminium Body Electric Motor Unit (EMU) is 3.6ton heaver than Stainless Steel(STS) body Electric Motor Unit(EMU). The system boundary of both Electric Motor Unit (EMU) are same life span and travel same distance. These both Electric Motor Unit (EMU) has same kind of environmental impact which is maximum Ozone Depletion(OD). During using period of these two models, the Aluminium Body Electric Motor Unit(EMU) has more global warming(GW) effect but Stainless Steel(STS) body Electric Motor Unit(EMU) has more Ozone Depletion(OD) effect. The above result is obtained by using LCA software PASS verson 3.1.3.

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A Study on Planning and Composition of Module Unit in Korean Traditional House (전통한옥 '칸'의 계획과 구성에 관한 연구)

  • Kim, Jong-Hoon
    • Journal of the Korean housing association
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    • v.23 no.4
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    • pp.41-48
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    • 2012
  • The purpose of the study, approaching from the aspect of the construction technologies, is to determine the architectural techniques of traditional wood architects in existence, through which the systems and techniques that create the inherent characteristics of Korean Architecture are clarified. With understanding traditional construction system and focusing on the fact that built environment results from the consistent standards and technologies of architects, this study inquires into the systematic standard and its formation that present in the process of planning for the overall scale and shape of a building from the following (four) perspectives. The study determines the characteristics of '間(Kan)' (unit; fundamental unit that measures Korean traditional houses) and the methods of columns disposition of which the '間 (Kan)' is made up. Once the necessary spaces are decided according to the size of a building, then floor plans are drawn with the standard unit, '間(Kan)'. The '間(Kan)', as a modular unit, is not only composing the floor plans, but also functioning as an Area unit, Space unit and Structural unit. Composition of '間(Kan)' varies with disposition of columns, and therefore multiform of floor and spaces are created. In this study, the '間(Kan)', as a standard unit, is used in the form of specific size and area, and it is demonstrated how the floor plans are developed by organizing the columns in accordance with the spaces requested.

The Study on NCS Development for the Production of Hanbok (한복생산 분야의 국가직무능력표준 개발에 관한 연구)

  • Suh, Seunghee;Kim, Jung-Sook
    • Journal of the Korean Society of Costume
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    • v.65 no.2
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    • pp.62-74
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    • 2015
  • The purpose of this research is to analyse the process of development and verification of 'National Competency Standards' of Hanbok production, which was carried out in 2013 for the fashion industry. As the result of this research, the definition of the duty in Hanbok production is 'to conduct a series of step-by-step processes of planning and developing fabric and design, then making pattern, cutting fabric and sewing.' The competency unit for Hanbok production is analyzed in 10 categories: analysis of market trends, design plan, production and manipulation of fabric, production process plan, sample making, pattern making, cutting out, sewing, finishing sewing, inspection of the product quality. Competency unit elements of each competency unit are as follows. 1) analysis of market trends: to research market trend resources, to analyse consumers' buying trend, to analyse industry changes, 2) design plan: to develop design, to plan fabrication, to draw flats, 3) production and manipulation of fabric: to develop fabric planning, to prepare fabric manipulation, to conduct fabric manipulation, 4) production process plan: to grasp design, to plan sewing method, to prepare a specification sheet, 5) sample making: to make a sample pattern, to cut sample fabrics, to sew sample, to finish sample making, 6) pattern making: to measure body, to make production pattern, to adjust production pattern, 7) cutting out: to care fabrics, to lay out patterns, to cut out fabrics, 8) sewing: to sew a garment, to sew a lining, to attach a lining, 9) finishing sewing: to neaten edges, to attach trims, to press to finish, 10) inspection of the product quality: to confirm correspondence with the specification sheet, to inspect appearance.