• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권1호
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• pp.302-320
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• 2017

In this paper, an innovative robust feature detection and matching strategy for visual odometry based on stereo image sequence is proposed. First, a sparse multiscale 2D local invariant feature detection and description algorithm AKAZE is adopted to extract the interest points. A robust feature matching strategy is introduced to match AKAZE descriptors. In order to remove the outliers which are mismatched features or on dynamic objects, an improved random sample consensus outlier rejection scheme is presented. Thus the proposed method can be applied to dynamic environment. Then, geometric constraints are incorporated into the motion estimation without time-consuming 3-dimensional scene reconstruction. Last, an iterated sigma point Kalman Filter is adopted to refine the motion results. The presented ego-motion scheme is applied to benchmark datasets and compared with state-of-the-art approaches with data captured on campus in a considerably cluttered environment, where the superiorities are proved.

• 복식문화연구
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• 제9권1호
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• pp.111-126
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• 2001

This study concentrates on the relationship between the early 20th century italian artists and their works in the field of clothing design. They advocated the creation of art for life and introduced a new type of work of art which I will call 'experimental clothing for art'. The experimental clothing for art showed its dynamic characteristics in the field s of line and form, color, pattern, and material. The Italian artists made simple and functionalistic dresses, using asymmetric, geometric cuts. in pattern making. They employed dynamic patterns in textile design and favored brilliant colors which they debunked as storage and traditional. With regard to material, they used unusual materials such as metal, net, wire, and paper and inexpensive materials. To investigations of the visual expression of experimental clothing for art in Italy have led us to the internal expressions which are avant-garde, dynamic & speed, functionality & popularity, ephemeral & transformable, and warlike. As a result of the reflection of the times and the artists's will and roles the experimental clothing for art in Italy implicated contemporary clothing in the early twentieth century and it was only laboratory art that underwent various experiments in canvas but a model of efforts for the at of living, which was anti-traditional. It offered a new future and created a new environment. It is left for future research how the experimental clothing for art developed in countries other than Italian.

• 한국대기환경학회지
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• 제17권1호
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• pp.85-96
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• 2001

The objective of this study is to develop the water spraying which can effectively by applied to the control or suppression of the fugitive dust generated from the scrap metal handling area at the Port of Inchon. As a first step toward this goal, we carried out some preliminary analyses on the chemical composition, physical shape, and particle size distribution of the sample dust. Next, to quantitatively investigate the effect of adding surfactants to the spraying water on the wettability of the sample dust, the Standard Sink Test was carried out for four different surfactants and at six different concentrations using the surfactants considered in this study. Results of from the preliminary analysis indicated that the main chemical component consisting of the sample dust is Goethite(FeO(OH)) and that the particles smaller than 10 ${\mu}{\textrm}{m}$ in geometric diameter occupy about 36% of the sample dust in mass. This result implies that the fugitive dust generated from the scrap metal handling area at the Port of Inchon should affect the environment nearby more than we have expected. This is because of relatively large mass percentage of the small metal particles less than 10${\mu}{\textrm}{m}$ in geometric diameter, what we may call respirable particles. As for the results of the Standard Sink Test, higher surfactant concentration tends to result in the higher wettability of the sample dust for the surfactants considered in this study, which in turn ensures the high particle collection efficiency of the droplets generated from the water spraying system. Based upon this preliminary results, studies to develop more sophisticated scaled model for dynamic test in underway and the effort to find the best surfactants as well as the optimum operating conditions are being made at the same time.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제14권3호
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• pp.321-325
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• 2008

위치정보기반 라우팅을 이용하는 무선 센서망은 자연환경 혹은 센서 노드들의 불균형적인 에너지 소비로 인한 라우팅 홀(hole)로 인해 높은 통신 장애 가능성이 존재한다. 이에 대해 연구된 대부분의 기법들은 그런 라우팅 홀을 우회하는 방법으로 접근하는 경향을 보인다. 그러나 홀 우회를 위한 라우팅은 홀 주변 센서노드들의 불균형적인 에너지 소비를 유도하기 때문에, 그들의 통신장애 및 네트워크 수명에 장애를 발생시킬 수 있다. 우리는 이미 홀 우회를 위한 라우팅 방안을 제안하였지만, 그 또한 갖는 문제점 때문에 가우시안 함수를 활용하여 그 연구에 대한 확장 방안을 새롭게 제안한다.

• 한국학교수학회논문집
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• 제11권3호
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• pp.513-541
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• 2008

본 연구의 목적은 8학년 학생들의 사각형 학습 및 기하학적 추론 능력의 발달을 위해서 GSP의 사용이 자와 각도기 같은 전통적인 도구의 사용보다 더 효과적인지를 탐구하고, 어떻게 그 소프트웨어의 사용이 학생들의 사각형 학습과 추론 능력의 발달에 영향을 끼치는지를 조사하는 것이다. 사후 학업 성취도 검사 결과에 의하면 GSP를 사용한 집단과 자와 각도기를 사용한 집단의 평균 성적에서 통계적으로 유의미한 차이가 발견되었다. GSP를 사용한 집단이 자와 각도기를 사용한 집단보다 유의미하게 높은 평균 성적을 보여주었다. 학생 면접 결과에 의하면, GSP의 사용이 학생들의 기하학적 추론 능력을 발달시키는데 더 효과적이었다. GSP를 사용한 집단의 학생들이 자와 각도기를 사용한 집단의 학생들보다 van Hiele 2와 3수준에서 더 높은 정도의 달성도를 보여주었다. GSP가 제공하는 수학적 개념에 대한 역동적인 시각적 효과와 조작 경험이 학생들이 사각형 학습을 개념적으로 접근하도록 하는데 중요한 역할을 하였고, 그런 경험들이 학생들이 기존에 갖고 있던 수학적 개념에 처한 오류를 확인하고 개념을 재정립하는데 도움을 주었다.

• 한국자동차공학회논문집
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• 제21권4호
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• pp.33-42
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• 2013

This paper describes a multiple vehicle tracking algorithm using an integrated probabilistic data association filter (IPDAF) in urban environments. The algorithm consists of two parts; a pre-processing stage and an IPDA tracker. In the pre-processing stage, measurements are generated by a feature extraction method that manipulates raw data into predefined geometric features of vehicles as lines and boxes. After that, the measurements are divided into two different objects, dynamic and static objects, by using information of ego-vehicle motion. The IPDA tracker estimates not only states of tracks but also existence probability recursively. The existence probability greatly assists reliable initiation and termination of track in cluttered environment. The algorithm was validated by using experimental data which is collected in urban environment by using single laser scanner.

• Asian Journal of Atmospheric Environment
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• 제6권4호
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• pp.304-313
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• 2012

In this study, the ${\AA}$ngstrom exponent for polydispersed aerosol during dynamic processes was investigated. Log-normal aerosol size distribution was assumed, and a sensitivity analysis of the ${\AA}$ngstrom exponent with regards the coagulation and condensation process was performed. The ${\AA}$ngstrom exponent is expected to decrease because of the particle growth due to coagulation and condensation. However, it is difficult to quantify the degree of change. In order to understand quantitatively the change in the ${\AA}$ngstrom exponent during coagulation and condensation, different real and imaginary parts of the refractive index were considered. The results show that the ${\AA}$ngstrom exponent is sensitive to changes in size distribution and refractive index. The total number concentration decreases and the geometric mean diameter of aerosols increase during coagulation. On the while, the geometric standard deviation approaches monodispersed size distribution during the condensation process, and this change in size distribution affects the ${\AA}$ngstrom exponent. The degree of change in the ${\AA}$ngstrom exponent depends on the refractive index and initial size distribution, and the size parameter changes with the ${\AA}$ngstrom exponent for a given refractive index or chemical composition; this indicates that the size distribution plays an important role in determining the ${\AA}$ngstrom exponent as well as the chemical composition. Subsequently, this study shows how the ${\AA}$ngstrom exponent changes quantitatively during the aerosol dynamics processes for a log-normal aerosol size distribution for different refractive indices; the results showed good agreement with the results for simple analytic size distribution solutions.

• Journal of Electrical Engineering and Technology
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• 제11권1호
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• pp.215-226
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• 2016

Modeling, control and implementation of a real redundant robot with five Degrees Freedom (DOF) of the SCARA (Selective Compliant Assembly Robot Arm) manipulator type is presented. Through geometric methods and structural and functional considerations, the inverse kinematics for redundant robot can be obtained. By means of a modification of the classical sliding mode control law through a hyperbolic function, we get a new algorithm which enables reducing the chattering effect of the real actuators, which together with the learning and adaptive controllers, is applied to the model and to the real robot. A simulation environment including the actuator dynamics is elaborated. A 5 DOF robot, a communication interface and a signal conditioning circuit are designed and implemented for feedback. Three control laws are executed in: a simulation structure (together with the dynamic model of the SCARA type redundant manipulator and the actuator dynamics) and a real redundant manipulator of the SCARA type carried out using MatLab/Simulink programming tools. The results, obtained through simulation and implementation, were represented by comparative curves and RMS indices of the joint errors, and they showed that the redundant manipulator, both in the simulation and the implementation, followed the test trajectory with less pronounced maximum errors using the adaptive controller than the other controllers, with more homogeneous motions of the manipulator.

• 한국철도학회논문집
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• 제6권4호
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• pp.300-307
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• 2003

Using a conventional railway, a tilting train was applied as a means of improving vehicle speed curve negotiation without any modification of infrastructure. In order to achieve the optimal car-body position control through the tilting mechanism, a dynamics analysis was required after the kinematics analysis of the tilting mechanism. For this, the geometric relationship of the linkage-type tilting mechanism was defined. Then, the equations of motion for the half car-body were derived. With the derived equations, the effect of the parameter change on performance was analyzed. The analysis result can be used in the optimum design of a tilting mechanism that considers the track environment, vehicle and operational conditions in which the tilting vehicle is applied.

• 대한기계학회논문집B
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• 제40권5호
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• pp.297-304
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• 2016

통상 제어기 설계용으로 개발되는 차량용 수퍼 차져의 동적 거동 모델은 경험식에 의존한 압축기 맵을 활용하고 있어, 실제 서지 현상의 발생에 따른 시스템의 영향과 거동특성을 모사하는데 한계가 있다. 본 연구에서는 수퍼 차져의 운전 동특성을 모사할 수 있는 해석기반 압축기 모델을 개발하고 운전 변동성에 따른 압축기의 운전 추이를 모사하고자 한다. 모델 개발은 SIMULINK$^{(R)}$ 환경에서 진행하고, 기준 동특성 모델은 Greitzer의 압축기 모델을 적용하였다. 해석 결과는 실험 결과와 비교 검증을 통해 모델의 타당성을 확인하였으며 운전 특성 변화에 따른 압축기 성능 및 서지 발생 가능성에 대해 확인 하였다.