• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.2
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• pp.213-220
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• 2016

This research aims to develop core technologies for passive carrier (no power in carrier itself) transfer system. The technologies are passive levitation, propulsion, and guidance, which can be great benefits for semiconductor and display manufacturing industries. Passive maglev carrier is necessary to precise position control for quiet and stable transfer operation. However, the structural characteristics of carrier and the installation errors of gap sensors cause the pitch motion. Hence, the controller design in consideration of pitch motion is required. This study deals with the reduction control of carrier pitch motion. PDA controller and PDA controller with pitch control are proposed to compare the pitch angle analysis. The pitch angle and the levitation precision are measured by experiment. Finally, the optimized design of pitch controller is presented and the effects are discussed.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2594-2599
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• 2003

We consider some problems of the Modified SPRT(Sequential Probability Ratio Test) method for fault detection and isolation of inertial redundant sensor systems and propose an Advanced SPRT method to solve the problems of the Modified SPRT method. One problem of the Modified SPRT method to apply to inertial sensor system comes from the effect of inertial sensor errors such as misalignment, scale factor error and sensor bias in the parity vector, which make the Modified SPRT method hard to be applicable. The other problem is due to the correlation of parity vector components which may induce false alarm. We use a two-stage Kalman filter to remove effects of the inertial sensor errors and propose the modified parity vector and the controlled parity vector which removes the effect of correlation of parity vector components. The Advanced SPRT method is derived form the modified parity vector and the controlled parity vector. Some simulation results are presented to show the usefulness of the Advanced SPRT method to redundant inertial sensor systems.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.56.1-56.1
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• 2015

The GMT-Consortium Large Earth Finder (G-CLEF) is the very first light instrument of the Giant Magellan Telescope (GMT) and an optical-band echelle spectrograph. The Flexure Control Camera (FCC) is one of the major contributions of KASI's for the spectrograph project. FCC system includes the Fiber Mirror monitoring and the on- and off-slit mode auto-guidance algorithm. In this study, we present the modified design of the FCC optics and opto-mechanics after the G-CLEF Preliminary Design Review (PDR) held in Cambridge in April 2015.

• Advances in aircraft and spacecraft science
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• v.10 no.4
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• pp.317-334
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• 2023

This paper presents a basic methodology and a set of numerical tools for the preliminary design of solid-fueled ramjet missiles. An elementary code determines the baseline system configuration comprised of warhead, guidance-control, and propulsion masses and geometries from specific correlations found in the literature. Then, the system is refined with the help of external and internal ballistics codes. Equations of motion are solved for the flight's ascending, cruising, and descending stages and the internal ballistic set of equations designs the ramjet engine based on liquefying fuels. The combined tools sized the booster and the ramjet sustainer engines for a long-range missile, intended to transport 200 kg of payload for more than 300 km range flying near 14,000 m altitude at Mach 3.0. The refined system configuration had 600 mm in diameter and 8,500 mm in length with overall mass of 2,128 kg and 890 kg/m3 density. Ramjet engine propellant mass fraction was estimated as 74%. Increased missile range can be attained with paraffin-polyethylene blend burning at near constant regression rate through primary air mass flow rate control and lateral 2-D air intakes.

• Research in Community and Public Health Nursing
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• v.11 no.2
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• pp.347-357
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• 2000

The purspose of this study is to examine the undergraduate students' attitudes, salient beliefs, perceived self-control and intentions for moderate drinking behavior of their own. Two hundred and twenty five students in two universities in Seoul and Suwon participated in this study. Questionnaires developed by this investigator under the guidance of the theory of planned behavior were used to collect data, Descriptive statistics, t-test, ANOVA. Pearson correlation coefficients. and multiple regression were used to analyze the data. The majority of the students showed positive attitudes toward the moderate drinking behavior. Students perceived conflict messages. however. from their significant others about their moderate drinking behavior. While parents and other family members as sisters and brothers strongly supported the moderate drinking behavior of students, friends and school-mates did not. More than half of the students did not intend to reduce their alcohol consumption in the near future. Students' attitudes and perceived self-control were the predictor variables of the intention while subjective norms were not. Students who intended to reduce their alcohol consumption showed a more positive attitude, subjective norm, and higher perceived self-control scores than who did not. These students who were intent for moderate drinking behavior spent less money for drinking, had less opportunities to drink, and drank small amounts of alcohol Moderate Drinking Behavior programs focusing on students who were heavy drinkers, however, did not intend to reduce their alcohol consumption should be developed focused on their characters. Programs for students who intended to reduce their alcohol consumption also recommended to help the students' positive intention continued.

• Journal of the Korean Society of Systems Engineering
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• v.13 no.1
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• pp.57-65
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• 2017

Recently, the ratio of electrical part and embedded software has grown in automotive industry. ISO 26262, 'Road Vehicles - Functional Safety', was published to guide development of automotive electrical and electronic part in 2011. This paper describes definition of functional safety and analyzes ISO 26262. The comparison of ISO 26262 and DO-178C is made, then difference between them is identified. DO-178C provides guidance for the production of software for airborne system and equipment. The core of DO-178C is a relatively minor update to the previous DO-178B, however, the big changes are captured in the supplemented documents such as DO-331, 'Model-Based Development and Verification Supplement to DO-178C and DO-278A'. Model-based design is important to develop automotive and aircraft meeting the guidelines of ISO 26262 and DO-178C. In this paper, the sample case of applying MBSE(Model-Based Systems Engineering) to AVCS(Active Vibration Control System) software development is discussed.

• Journal of the Korean Society of School Health
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• v.18 no.2
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• pp.93-104
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• 2005

Purpose： This study compared lifestyles of middle school students with and without atopic dermatitis in order to obtain the baseline information for health education. Methods： This study involved 256 students from 20 middle schools in Busan who suffered from atopic dermatitis and 231 students from 2 middle schools in Busan who did not have atopic dermatitis. Results： Students with atopic dermatitis had a lower family income (탑=16.99, p<.001) and were more likely to come from a nuclear family (탑=10.28, p<.001) than control students. 98% of the students with atopic dermatitis had several skin symptoms. 78.5% of students with atopic dermatitis reported experiencing difficulties in their daily because of their condition. Students with atopic dermatitis took shorter baths and used soap less frequently than the students in the control group. The students with atopic dermatitis cleaned their houses and bedclothes more often than normal students in an attempt to remove cockroaches and house-dust mites. Students with atopic dermatitis also ate fast and instant foods more often than normal students. Conclusions： Some lifestyle differences exist between students with and without atopic dermatitis. Therefore, education and guidance may be important to promote good health and improve lifestyle quality.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.1
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• pp.76.2-76.2
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• 2013

SPICA(SPace Infrared Telescope for Cosmology and Astrophysics) is an infrared space observatory with cooled telescope of 3 m aperture. Because of its large aperture, near- and mid-infrared instruments onboard SPICA require fine guidance with attitude accuracy less than 0.1 arcsecond. The FPC-G is a focal plane camera to achieve this high attitude accuracy and KASI is leading its development. The SPICA project is now under the Risk Mitigation Phase 2 (RMP2) and one of major risks is to satisfy the requirement of pointing and attitude control. To assess the impacts of disturbance sources on the attitude control and devise methods to mitigate possible risks, a software simulator of the FPC-G is under the development. In this presentation, we report the status of development of the simulator and the development plan during the RMP2.

• Journal of the Korean housing association
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• v.14 no.1
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• pp.61-66
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• 2003

Considering the present outdoor environment of city landscapes, the improvement of well-formed street landscapes is a very important issue in Korea. At this point of time, it is very meaningful to understand the sign design and the planning condition of buildings and examine various problems about this and the possibilities for improvement. Thus the purpose of this study is to accumulate basic data to establish design guideline and visual factors for the sign design for useful environment. The conclusions of this study are as follows: to understand the factors of sign designs is through survey and analysis of building condition and city landscape. Planning factors for outdoor advertising design should be developed systematically and more fit to the street environment and designers in the aspect of control and guidance.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.3
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• pp.349-360
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• 2018

This paper proposes various methods for constructing a HWIL simulation system including Inertial Navigation System(INS) and Guidance Control Unit(GCU) under the assumption that the INS identifies the initial attitude of an aviation body through its own alignment and that it is a package consisting of an inertial sensor and a navigation computation module. This paper also presents a real-time computing technology and a way to calculate the command of the Flight Motion System(FMS) analogous to the acutal flight environment. The proposed HWIL simulation system is constructed by applying the above-mentioned methods and the results of running a series of simulations confirm high effectiveness and usefulness of the system. Finally, minor error factors that could be acquired only in HWIL simulation Environment are analyzed.