• 한국자동차공학회논문집
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• 제8권4호
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• pp.169-176
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• 2000

Longitudinal and lateral forces acting on tires are known to be closely related to the tract-ability braking characteristics handling stability and maneuverability of ground vehicles. In thie paper in order to develop tire force monitoring systems a monitoring model is proposed utilizing not only the vehicle dynamics but also the roll motion. Based on the monitoring model three monitoring systems are developed to estimate the tire force acting on each tire. Two monitoring systems are designed utilizing the conventional estimation techniques such as SMO(Sliding Mode Observer) and EKF(Extended Kalman Filter). An additional monitoring system is designed based on a new SKFMEC(Scaled Kalman Filter with Model Error Compensator) technique which is developed to improve the performance of EKF method. Tire force estimation performance of the three monitoring systems is compared in the Matlab simulations where true tire force data is generated from a 14 DOF vehicle model with the combined-slip Magic Formula tire model. The built in our Lab. simulation results show that the SKFMEC method gives the best performance when the driving and road conditions are perturbed.

• 한국주거학회논문집
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• 제22권6호
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• pp.71-82
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• 2011

Recently the crime against elementary school students has been rapidly increasing. Under these circumstances, this study is to analyze the basic principles of Crime Prevention Through Environmental Design (CPTED) for the elementary school in urban residential area, and suggest some planning and design guidelines. Among 59 elementary schools in Pyongchon, Bundang, and Pangyo new towns, 11 distinctive schools were selected for analysis study. School cases were investigated comparatively from the viewpoints of visibility, securing of observers, activity support and reinforced territoriality on the basis of theoretical crime prevention concepts. The analysis adopts various methods including theoretical research, field study, observation, and examination of plan. Some of findings of this analysis are as follows. Most of schools rely on the mechanical and physical devices such as CCTV, gate control, or walls, which are considered to be quite passive measures and ineffective for the crime prevention. Other effective methods such as offering school facilities to the public or public space sharing with surrounding residents, for the protection of crimevulnerable students by public eyes. Therefore, in order to prevent crimes effectively, it is urgently required to analyze the environments around and in the school, and to improve physical conditions on the basis of CPTED principles.

• Imaging Science in Dentistry
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• 제31권3호
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• pp.153-158
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• 2001

Purpose : To determine the head position that the superior border of the mandibular canal as well as mental foramen can be more clearly visualized in panoramic radiography Materials and Methods : Ten dry mandibles were radiographed bilaterally using PM 2002 CC panoramic machine. A 20 mm thick aluminium filter was added to the slit collimator to obtain radiographs with acceptable density. The specimens were tilted by 2, 4, 6, 8, and 10 degrees downward with and without radiopaque markers. Radiopaque markers were inserted into the mandibular canals and the mental canals of each side of the specimens to serve as reference image when assessing the radiographs. The visibility of the mandibular canal and the mental foramen was estimated by 4 observers on all radiographs. The obtained results were analyzed statistically. Results: Mandibular canals were significantly more clearly visible in the radiographs with 4 and 6 degree downward position on both sides (P<0.05). Mental foramens were significantly more clearly visible in the radiographs with 4, 6, and 8 degree downward on right side and 6 degree downward on left side (P<0.05). There was not significant difference between right and left sides. Conclusion: Panoramic radiographs with 4 to 6 degree downward tilting could be valuable in locating the mandibular canal as well as the mental foramen.

• 천문학회보
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• 제40권2호
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• pp.48.1-48.1
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• 2015

Active galactic nuclei (AGNs) are powered by a supermassive black hole with an accretion disk and exhibit prominent broad and narrow emission lines. The unification model AGNs requires the presence of a geometrically and optically thick torus component that hides the broad line region from observers lying in the equatorial direction. The strong far UV radiation characterizing AGN spectra is expected to be scattered inelastically in the torus region to reappear around hydrogen Balmer lines or Paschen lines in the form of broad wings. Adopting a Monte Carlo technique we produce broad wings around $H{\alpha}$, $H{\beta}$ and $Pa{\alpha}$ that are formed through Raman scattering. The widths of the wings are mainly affected by the neutral column density of the torus, and the overall strengths are primarily determined by the covering factor and the column density of the neutral region. It is concluded that deep spectroscopy of AGNs of broad wings around hydrogen emission lines may shed much light on the AGN unification model.

• Neonatal Medicine
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• 제25권2호
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• pp.72-77
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• 2018

Purpose: Glucose has been recommended as an analgesic for mild to moderately painful procedures in neonates. The goal of this study was to assess the optimal dextrose concentration for pain control in newborns. Methods: This prospective, randomized, blinded clinical trial included 116 healthy full-term newborns. The neonates were randomly assigned to the following four groups by drawing straws: groups receiving sterile water or a 10%, 20%, or 40% dextrose solution orally. Each group was treated with the assigned solution prior to hepatitis B vaccination. The Neonatal Facial Coding System (NFCS) and the Neonatal Infant Pain Scale (NIPS) scores were evaluated before, immediately after, and 2 minutes after the injection in all neonates. Premature Infant Pain Profile (PIPP) scores were evaluated during the injection. All procedures were video-recorded, and pain scores were assessed by two independent observers who were not involved in the care of the newborns studied. The pain scores were compared among the four groups. Results: The 40% dextrose solution significantly reduced the NFCS (P=0.002) and the PIPP scores (P=0.001) compared with sterile water. No hyperglycemic events were noted in the study subjects 2 hours after the injection. Conclusion: The 40% dextrose solution effectively relieved pain due to intramuscular injection in full-term newborns without causing hyperglycemic events. However, the 10% and 20% dextrose solutions did not affect neonatal pain scores.

• 공학교육연구
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• 제13권5호
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• pp.15-19
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• 2010

Upon request from the Tokushima Prefectural Senior High School of Science and Technology, two faculty staff members and eight students of The University of Tokushima visited the high school and set up a chemistry laboratory class for 59 students. Since the participating senior high school students were freshmen, four simple, safe and visual experiments were selected: 1) Water purification, 2) Surface modification, 3) Briggs-Rauscher reaction, and 4) Polymer synthesis and characterization. All experiments received a favorable reception as a follow-up questionnaire verified. Since the high school students enjoyed the experiments it is hoped that the results will strengthen the students' interest in chemistry. It was good opportunity for the observers; they recognized the difficulty of teaching students.

• 한국항공우주학회지
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• 제41권4호
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• pp.284-290
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• 2013

위성의 각속도를 추정하고 반작용 휠의 고장을 검출하기 위하여 비선형 미지입력 관측기를 제안하였다. 위성의 각속도 추정을 위해서 입력 값을 필요로 하는데, 구동기에 고장이 발생하는 경우에 정확한 각속도 추정이 어렵다. 미지입력 관측기는 미지의 고장에 영향을 받지 않으면서 상태추정이 가능하다. 본 논문에서는 SDRE 기법을 적용하여 비선형 미지입력 관측기를 설계하였고, 시뮬레이션을 이용하여 제안한 방법을 검증하였다. 다양한 형태로 동시에 고장이 발생하더라도, 각속도 추정 및 고장 검출이 가능하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 하계학술대회 논문집
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• pp.670-677
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• 1991

All models of dynamical systems invariably have some measure of uncertainties associated with some of their dynamics. The recent approaches to establish robustness of stabilizing feedback control against the possible uncertainties have a serious limitation, that is, their applicability only to the systems that satisfy the matching conditions. Such conditions are rarely met in general applications. If a particular system satisfies the matching conditions, the addition of an actuator will destroy the satisfaction of such conditions. In this paper, we develop robust control algorithm for uncertain multivariable systems in which the matching conditions are not necessarily met. In order to eliminate an influence over partial state variables due to unknown constant disturbances we perform the appropriate block-decomposition for a given system. Functional observers are introduced to estimate the unknown constant disturbances. The sliding mode controller is designed in such a way that the partial state variables in the state-space are directed towards switching surfaces and regulated to the origin asymptotically. Numerical examples are discussed as illustrations.

• 한국HCI학회논문지
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• 제4권2호
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• pp.9-16
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• 2009

최근 3차원 입체 디스플레이에 대한 관심이 증가하고 있다. 무안경식 다시점 입체 디스플레이(Multiple-view Autostereoscopic Display)는 관찰자가 셔터 글래스(Shutter glasses)또는 HMD(Head Mounted Display)와 같은 특별한 장치를 착용하지 않고도 여러 시점(Multiple-view)에서 입체 영상을 볼 수 있어 가상현실(Virtual Reality), 모바일, 3D TV 등의 분야에서 각광 받고 있다. 하지만, 디스플레이 설계 시 정해진 거리와 시역 내에 관찰자가 위치해 있어야만 입체 영상을 볼 수 있다는 문제점이 있다. 본 연구에서는 무안경식 다시점 입체 디스플레이 시스템을 구축하여 이 시스템에서 관찰자의 시점 변경에도 실시간으로 자연스러운 3차원 입체 영상을 보여 주기 위한 효율적인 GPU기반 렌더링 기법을 제안한다.

• 한국전자통신학회논문지
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• 제15권5호
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• pp.907-912
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• 2020

전동기의 수학적 모델 오차와 작용하는 외란을 고려하여 제어기를 설계하는 것이 강건하며 정밀한 제어 성능을 좌우한다. 강건하며 정밀한 제어를 위하여 기계적인 부분과 전기적인 부분의 외란 관측기를 설계하여 외란을 추정하고, 공칭 시스템으로 설계된 속도제어기와 전류 제어기에 나누어 적용하였다. 설계된 시스템의 제어 성능을 확인하고자 120 [W]급의 BLDC 전동기에 적용하여, 속도 추종제어의 결과 외란을 극복하고 정상상태 오차가 영으로 수렴하며, 점근적 안정한 결과를 확인할 수 있다.