• Journal of Computational Design and Engineering
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• 제2권1호
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• pp.26-37
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• 2015

A lot of researchers have been investigating interactive portable projection systems such as a mini-projector. In addition, in exhibition halls and museums, there is a trend toward using interactive projection systems to make viewing more exciting and impressive. They can also be applied in the field of art, for example, in creating shadow plays. The key idea of the interactive portable projection systems is to recognize the user's gesture in real-time. In this paper, a vision-based shadow gesture recognition method is proposed for interactive projection systems. The gesture recognition method is based on the screen image obtained by a single web camera. The method separates only the shadow area by combining the binary image with an input image using a learning algorithm that isolates the background from the input image. The region of interest is recognized with labeling the shadow of separated regions, and then hand shadows are isolated using the defect, convex hull, and moment of each region. To distinguish hand gestures, Hu's invariant moment method is used. An optical flow algorithm is used for tracking the fingertip. Using this method, a few interactive applications are developed, which are presented in this paper.

• 한국지능시스템학회:학술대회논문집
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• 한국지능시스템학회 2008년도 춘계학술대회 학술발표회 논문집
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• pp.400-402
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• 2008

인간과 컴퓨터간의 정보이동에 중요한 역할을 해온 인간-컴퓨터 상호작용(HCI)기술은 핵심적인 정보기술 분야에 속한다. 최근 키보드와 마우스와 같은 입력장치의 사용없이 인간의 몸짓이나 손짓등과 같은 Gesture를 입력으로 사용하여 로봇이나 제어 장치들을 제어하는 연구가 다각도로 진행되고 있으며 그 중요성 또한 날로 증가하고 있다. 본 논문에서는 가속도 센서에서 계측된 정보를 PCA알고리즘에 적용하여 사용자의 제스처를 인식하는 기법을 제안하고자 한다.

• Geomechanics and Engineering
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• 제36권2호
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• pp.167-181
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• 2024

The soil-structure relative stiffness is a key factor affecting the seismic response of underground structures. It is of great significance to study the soil-structure relative stiffness for the soil-structure interaction and the seismic disaster reduction of subway stations. In this paper, the dynamic shear modulus ratio and damping ratio of an inhomogeneous soft soil site under different buried depths which were obtained by a one-dimensional equivalent linearization site response analysis were used as the input parameters in a 2D finite element model. A visco-elasto-plastic constitutive model based on the Mohr-Coulomb shear failure criterion combined with stiffness degradation was used to describe the plastic behavior of soil. The damage plasticity model was used to simulate the plastic behavior of concrete. The horizontal and vertical relative stiffness ratios of soil and structure were defined to study the influence of relative stiffness on the seismic response of subway stations in inhomogeneous soft soil. It is found that the compression damage to the middle columns of a subway station with a higher relative stiffness ratio is more serious while the tensile damage is slighter under the same earthquake motion. The relative stiffness has a significant influence on ground surface deformation, ground acceleration, and station structure deformation. However, the effect of the relative stiffness on the deformation of the bottom slab of the subway station is small. The research results can provide a reference for seismic fortification of subway stations in the soft soil area.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(4)
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• pp.222-225
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• 2000

Human frequently communicate non-linguistic information with gesture. So, we must develop efficient and fast gesture recognition algorithms for more natural human-computer interaction. However, it is difficult to recognize gesture automatically because human's body is three dimensional object with very complex structure. In this paper, we suggest a method which is able to detect key frames and frame changes, and to classify image sequence into some gesture groups. Gesture is classifiable according to moving part of body. First, we detect some frames that motion areas are changed abruptly and save those frames as key frames, and then use the frames to classify sequences. We symbolize each image of classified sequence using Principal Component Analysis(PCA) and clustering algorithm since it is better to use fewer components for representation of gestures. Symbols are used as the input symbols for the Hidden Markov Model(HMM) and recognized as a gesture with probability calculation.

• 한국CDE학회논문집
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• 제17권6호
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• pp.417-425
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• 2012

In recent years, great attention has been paid to using simple physical objects as tangible objects to improve user interaction in augmented reality (AR) environments. In this paper, we address AR-based user interaction using tangible objects, which has been used as a key component for virtual design evaluation of engineered products including digital handheld products. We herein consider the use of two types (product-type and pointer-type) of tangible objects. The user creates input events by touching specified parts of the product-type object with the pointer-type object, and the virtual product reacts to the events by rendering its visual and auditory contents on the output devices. The product-type object is used to reflect the geometric shape of a product of interest and to determine its position and orientation in the AR environment. The pointer-type object is used to recognize the reference position of the pointer (or finger) in the same environment. The rapid prototype of the product is employed as a good alternative to the product-type object, but various alternatives to the pointer-type object can be considered according to fabrication process and touching mechanism. In this paper, we present four alternatives to the pointer-type object and investigate their strong and weak points by performing experimental comparison of their various aspects including interaction accuracy, task performance, and qualitative user experience.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.162-169
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• 2003

Excavation by TBM can be characterized by a rock-machine interaction during the cutting process on a small scale, but on a large scale the interaction between the rock mass and TBM becomes very significant. For the planning and evaluation of TBM tunnelling it needs to understand rock fracture mechanism by a cutter or cutters on a small scale, and to estimate penetration rate, advance rate and utilization on a large scale. In this study rock chipping mechanism due to cutter-penetration is analysed by numerical simulation, showing that rock chipping is mainly occurred by tensile failure. Also, through the analysis of factors that affect on TBM procedures in various assessment systems, it is determined that the key elements that should be considered in the planning and evaluation of TBM tunnelling are classified into rock properties, the geological structures and properties of rock mass, and the structural and functional specifications of the machine. The user-friendly assessment tool is developed, so that penetration rate, advance rate and TBM utilization are evaluated from various input data. The tool developed in this study can be applied to a practical TBM tunnelling by understanding TBM tunnelling procedures.

• 한국지진공학회논문집
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• 제20권5호
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• pp.301-310
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• 2016

There are differences in seismic behavior between non-skewed bridges and skewed bridges due to in-plane rotations caused by pounding between the skewed deck and its abutments during strong earthquake. Many advances have been made in developing design codes and guidelines for dynamic analyses of non-skewed bridges. However, there remain significant uncertainties with regard to the structural response of skewed bridges caused by unusual seismic response characteristics. The purpose of this study is performing non-linear time history analysis of the bridges using abutment-soil interaction model considering pounding between the skewed deck and its abutments, and analyzing global seismic behavior characteristics of the skewed bridges to assess the possibility of unseating. Refined bridge model with abutment back fill, shear key and elastomeric bearing was developed using non-linear spring element. In order to evaluate the amplification of longitudinal and transverse displacement response, non-linear time history analysis was performed for single span bridges. Far-fault and near-fault ground motions were used as input ground motions. According to each parameter, seismic behavior of skewed bridges was evaluated.

• 한국멀티미디어학회논문지
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• 제25권2호
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• pp.221-236
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• 2022

BLE protocol prevents MITM attacks with user interaction through some input/output devices such as keyboard or display. Therefore, If it use a device which has no input/output facility, it can be vulnerable to MITM attack. If messages to be sent to a control device is forged by MITM attack, the device can be abnormally operated by malicious attack from attacker. Therefore, we describes a scenario which has the vulnerabilities of the BLE network in this paper and propose countermeasure method against MITM attacks integrity violations. Its mechanism provides data confidentiality and integrity with MD5 and security key distribution of Diffie Helman's method. In order to verify the effectiveness of the countermeasure method proposed in this paper, we have conducted the experiments. ​As experiments, the message was sent 200 times and all of them successfully detected whether there was MITM attack or not. In addition, it took at most about 4.2ms delay time with proposed countermeasure method between devices even attacking was going on. It is expected that more secure data transmission can be achieved between IoT devices on a BLE network through the method proposed.

• 인터넷정보학회논문지
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• 제15권4호
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• pp.9-20
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• 2014

대상의 동작을 잘 예측하는 것은 사회적 상호작용과 의사결정 컨텍스트 이해의 핵심이다. 본 연구는 동작 인식 과정에서 인간 뇌 시각인지 과정을 모방한 방법으로 관절 동작의 동작 순서 패턴을 학습하는 컴퓨팅 모델을 제안하였다. 제안 방법의 핵심은 뇌에서 동작 인지 자극을 처리하는 신경생리학적 IT, MT, STS의 피질 기능과 특정 시각 신경 회로 네트워크 기능을 모방하여 비지도 방법으로 동작 순서를 학습한 후 동작을 예측, 인식하는 것이다. 실험을 통해 제안 모델이 어떻게 연속적으로 입력되는 비디오에서 의미있는 동작 스냅샷 뿐 아니라 중요한 동작 패턴을 자동으로 선택하는 지를 제시하였다. 이 핵심 움직임은 학습 네트워크가 정적 시점에서 정지 영상에 함축된 동작을 인식하는지를 증명하는데 이용하는 관절 자세이다. 또한 STS 피질 영역에서 어떻게 정지와 움직임 입력을 통합하는지를 모방하여 학습하고, 학습한 피드백 연결이 차후 동작의 입력 순서를 어떻게 예측하는지를 제시하였다. 네트워크 시뮬레이션을 통해 동작 인식에 대한 제안 모델의 우수성을 입증하였다.

• 감성과학
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• 제15권4호
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• pp.553-564
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• 2012

본 연구는 실물형 인터페이스 개념과 특징을 설명하고 있는 선행연구를 대상으로 실물형 인터페이스디자인에 대한 특성을 토출하여 이를 토대로 실물형 인터페이스 디자인 가이드라인을 제안하였다. 도출된 인터페이스 디자인 가이드 라인의 특성은 물리적 조작성, 기기의 용이성 및 편리성, 지각적 표현성, 상황인지 및 공간성, 그리고 사회적 상호작용으로 구분되었으며 25개의 세부항목이 추출되었다. 개발된 가이드라인은 사용자와의 상호작용 측면이 강조된 것으로 이를 실제공간의 체험형 전시물들에 적용하여 평가함으로써 현 실물형 인터페이스 디자인의 특성을 분석하였다. 조사대상으로 선정된 국립과학 박물관의 전시 설치물들 중 실물형 인터페이스 평가가 가능하다고 판단되는 15개의 설치물을 대상으로 개발된 디자인 가이드 라인에 따라 전문가 평가를 하였다. 평가결과 신체모션을 이용한 인터페이스에 대한 점수가 가장 높았으며 이들은 상황인지 및 공간성 영역에서 높은 평가를 받았다. 상황인지 및 공간성은 새로이 확장된 실물형 인터페이스 특성으로 최근 그 중요성이 강조되고 있다. 분석 결과 대부분의 설치물들은 버튼과 조이스틱 위주의 물리적 조작성을 제공하는 설치물이 가장 많았으나 향후 시각, 청각, 촉각 등의 다감각 인터페이스나 사용자가 직접 설치장치들을 재배열하는 인터렉션 개발 등이 필요하였다. 본 연구는 실물형 인터페이스 디자인을 평가할 수 있는 기준을 제시하였다는데 그 의의가 있으며 실물형 인터페이스디자인이 적용된 전시 설치물들이 개발되고 적용됨에 있어 발전 방향을 모색하는데 도움을 줄 것으로 기대한다. 향후 개발된 실물형 인터페이스 디자인 가이드 라인에 따라 전문가 평가뿐만 아니라 실제 사용자들을 대상으로 하는 사용자 경험 평가가 병행되어야 할 것이다.