• 제어로봇시스템학회논문지
• /
• 제13권6호
• /
• pp.542-546
• /
• 2007

In the vision of ubiquitous computing environment, smart objects would communicate each other and provide many kinds of information about user and their surroundings in the home. This information enables smart objects to recognize context and to provide active and convenient services to the customers. However in most cases, context-aware services are available only with expert systems. In this paper, we present generalized activity recognition application in the smart home based on a naive Bayesian network(BN) and fuzzy clustering. We quantize continuous sensor data with fuzzy c-means clustering to simplify and reduce BN's conditional probability table size. And we apply mutual information to learn the BN structure efficiently. We show that this system can recognize user activities about 80% accuracy in the web based virtual smart home.

• Earthquakes and Structures
• /
• 제14권5호
• /
• pp.411-424
• /
• 2018

This study explores the inelastic behavior of systems with flexible base. The use of a single degree of freedom system (ESDOF) with equivalent ductility to represent the response of flexible base systems is discussed. Two different equations to compute equivalent ductility are proposed, one which includes the contribution of rigid body components, and other based on the overstrength of the structure. In order to asses the accuracy of ESDOF approach with the proposed equations, the behavior of a 10-story regular building with reinforced concrete (RC) moment resisting frames is studied. Local and global ductility capacity and demands are used to study the modifications introduced by base flexibility. Three soil types are considered with shear wave velocities of 70, 100 and 250 m/s. Soil-foundation stiffness is included with a set of springs on the base (impedance functions). Capacity curves of the building are computed with pushover analysis. In addition, non linear time history analysis are used to asses the ductility demands. Results show that ductility capacity of the soil-structure system including rigid body components is reduced. Base flexibility does not modify neither yield and maximum base shear. Equivalent ductility estimated with the proposed equations is fits better the results of the numerical model than the one considering elastoplastic behavior. Modification of beams ductility demand due to base flexibility are not constant within the structure. Some elements experience reduced ductility demands while other elements experience increments when flexible base is considered. Soil structure interaction produces changes in the relation between yield strength reduction factor and structure ductility demand. These changes are dependent on the spectral shape and the period of the system with fixed and flexible base.

• 정보처리학회논문지D
• /
• 제11D권5호
• /
• pp.1205-1212
• /
• 2004

전자상거래 시스템의 보급이 활성화되기 시작하면서, 사용자의 필요와 욕구에 밀착한 적응형 전자상거래 에이전트의 필요성이 증대되고 있다. 이와 같은 적응형 전자상거래 에이전트는 사용자의 행위를 모니터하고 자동 분류하여 사용자의 취향을 학습하는 기능을 요하게 되었다. 이러한 기능을 가지는 적응형 전자상거래 에이전트를 구축하기 위해서, 본 논문에서는 사용자 개인의 관심정보와 선호하는 상품에 대한 호감도를 고려한 적응형 전자 상거래 에이전트 시스템을 제안한다. 제안하는 시스템은 사용자의 구매 행위에 적응력을 가질 수 있도록 보다 정확한 사용자 프로파일을 구축하고, 이와 같은 사용자 프로파일을 기반으로 사용자에게 불필요한 검색과정 없이 필요한 상품 정보를 제공 할 수 있도록 한다. 본 시스템에서는 모니터링을 통하여 사용자 의도를 파악하는 모니터 에이전트, 사용자의 행동성향을 학습 한 후 행동 패턴이 유사한 그룹을 참조하는 유사도 참조 에이전트, 사용자의 행위의 변화에 따른 개인화된 행동 DB를 구축할 수 있는 관심 추출 에이전트로 구성하였다.

• 경영정보학연구
• /
• 제19권3호
• /
• pp.179-199
• /
• 2017

멀티채널 소비자들의 크로스오버 쇼핑행동이 두드러지는 시점에서 최근 사용자 행동 메커니즘에 대한 관심이 높아지고 있다. 단순한 멀티채널 사용자행동에 대한 이해 차원을 넘어 면밀한 관찰을 통해 기존 연구방식에서 발견할 수 없었던 크로스 오버 쇼핑행동에 대한 연구 축적이 필요한 시점이라 할 수 있다. 본 연구는 근거이론(grounded theory)를 활용하여 멀티채널 사용자들이 왜, 어떻게 크로스오버 쇼핑행동을 하는지를 살펴보는데 그 목적이 있다. 본 연구에서는 총 25명의 응답자를 대상으로 인터뷰를 진행하였으며, 근거자료의 분석을 통해 118개의 개념을 추출하였고, 유사 개념간의 통합과정을 통해 28개의 범주를 제시하였다. 본 연구는 근거이론을 적용하여 기존 설문연구에서는 파악하기 어려웠던 사용자들의 동적인 탐색과 구매행동의 메커니즘을 포착함으로써 멀티채널 환경에서 설명 가능한 행동연구 방안을 제안하고 있다는 점에서 의의가 있다.

• 한국산업정보학회:학술대회논문집
• /
• 한국산업정보학회 1999년도 추계공동학술대회 논문집:21세기지식경영과 정보기술
• /
• pp.769-781
• /
• 1999

Manufacturing systems are usually large, complex, and concurrent in nature that makes it difficult to model and simulate the behavior in advance. The paper proposes an approach, called OPNets, for modeling and validating manufacturing systems. The approach is based on object-oriented high-level Petri nets in which modeling components of Petri net are constructed into object hierarchy. The objects communicate with each other by passing messages. To enhance the reusability and maintainability, a system are developed by object hierarchy. Inheritance among object hierarchy is also supported in OPNets. The modeling scheme of OPNets tries to resolve the complexity problems of Petri net.

• 한국산업융합학회 논문집
• /
• 제25권2_2호
• /
• pp.193-198
• /
• 2022

In this paper, we introduce the improved control method are communicated between a master and a slave robot in the teleoperation systems. When the master and slave robots are located in different places, time delay is unavoidable under the network environment and it is well known that the system can become unstable when even a small time delay exists in the communication channel. The time delay may cause instability in teleoperation systems especially if those systems include haptic feedback. This paper presents a control scheme based on the estimator with virtual master model in teleoperation systems over the network. As the behavior of virtual model is tracking the one of master model, the operator can control real master robot by manipulating the virtual robot. And LQG/LTR scheme was adopted for the compensation of un-modeled dynamics. The approach is based on virtual master model, which has been implemented on a robot over the network. Its performance is verified by the computer simulation and the experiment.

• 대한기계학회논문집A
• /
• 제27권7호
• /
• pp.1146-1151
• /
• 2003

In this paper, results of an analysis of driving behavior characteristics and a driver-adaptive control algorithm for adaptive cruise control systems have been described. The analysis has been performed based on real-world driving data. The vehicle longitudinal control algorithm developed in our previous research has been extended based on the analysis to incorporate the driving characteristics of the human drivers into the control algorithm and to achieve natural vehicle behavior of the adaptive cruise controlled vehicle that would feel comfortable to the human driver. A driving characteristic parameters estimation algorithm has been developed. The driving characteristics parameters of a human driver have been estimated during manual driving using the recursive least-square algorithm and then the estimated ones have been used in the controller adaptation. The vehicle following characteristics of the adaptive cruise control vehicles with and without the driving behavior parameter estimation algorithm have been compared to those of the manual driving. It has been shown that the vehicle following behavior of the controlled vehicle with the adaptive control algorithm is quite close to that of the human controlled vehicles. Therefore, it can be expected that the more natural and more comfortable vehicle behavior would be achieved by the use of the driver adaptive cruise control algorithm.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제10권6호
• /
• pp.2781-2800
• /
• 2016

Emerging attacks aim to access proprietary assets and steal data for business or political motives, such as Operation Aurora and Operation Shady RAT. Skilled Intruders would likely remove their traces on targeted hosts, but their network movements, which are continuously recorded by network devices, cannot be easily eliminated by themselves. However, without complete knowledge about both inbound/outbound and internal traffic, it is difficult for security team to unveil hidden traces of intruders. In this paper, we propose an autonomous anomaly detection system based on behavior profiling and relation mining. The single-hop access profiling model employ a novel linear grouping algorithm PSOLGA to create behavior profiles for each individual server application discovered automatically in historical flow analysis. Besides that, the double-hop access relation model utilizes in-memory graph to mine time-sequenced access relations between different server applications. Using the behavior profiles and relation rules, this approach is able to detect possible anomalies and violations in real-time detection. Finally, the experimental results demonstrate that the designed models are promising in terms of accuracy and computational efficiency.

• Smart Structures and Systems
• /
• 제31권6호
• /
• pp.585-599
• /
• 2023

Field monitoring techniques offer an attractive approach for understanding bridge behavior under in-service loads. However, the investigations on bridge behavior under high-speed train load using field monitoring data are limited. The focus of this study is to explore the structural behavior of an in-service long-span steel truss arch bridge based on field monitoring data. First, the natural frequencies of the structure, as well as the train driving frequencies, are extracted. Then, the train-induced bearing displacement and structural strain are explored to identify the effects of train loads and bearings. Subsequently, a sensitivity analysis is performed for the impact factor of strain responses with respect to the train speed, train weight, and temperature to identify the fundamental issues affecting these responses. Additionally, a similar sensitivity analysis is conducted for the peak acceleration. The results indicate that the friction force in bearings provides residual deformations when two consecutive trains are in opposite directions. In addition, the impact factor and peak acceleration are primarily affected by train speed, particularly near train speeds that result in the resonance of the bridge response. The results can provide additional insight into the behavior of the long-span steel truss bridges under in-service high-speed train loads.

• 진공이야기
• /
• 제1권1호
• /
• pp.11-16
• /
• 2014

A variety of metal vacuum systems displays the celebrated 1/t pressure, namely, power-law dependence on time t, with the exponent close to unity, as to the origin of which there has been long-standing controversy. Here we propose a chemisorption model for water adsorbates, based on the argument for 2D fermion behavior of water adsorbed on a metal surface, and obtain analytically the power-law behavior of pressure with an exponent unity. Further, the model predicts that the pressure should depend on the temperature T according to $T^{1.5}$, which is indeed confirmed by our experiment.