• Journal of information and communication convergence engineering
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• 제11권3호
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• pp.167-172
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• 2013

Recently, mobile communication systems are suffering from exponentially increasing data traffic. As a promising solution to the increase in data traffic, a coordinated multi-point transmission and reception (CoMP) scheme has been proposed. Although a great deal of research has been done on this new technology, the performance of mobile communication systems with CoMP has not been evaluated properly in a typical indoor environment. To address this, we have developed a system-level simulator and evaluated the performance of mobile communication systems with CoMP. Unlike previous works, we have used an actual antenna pattern in our simulator and link-level results are properly taken into account through link-level abstraction. By using a system-level simulator, we have evaluated the performance of mobile communication systems with CoMP in an indoor environment and found that unlike an outdoor cellular environment, CoMP may not improve the performance of overall mobile communication systems in an indoor environment.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.133-138
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• 1993

This paper presents neural network based position estimation method in slippery environment as an approach to solve one of problems which are engaged in dead reckoning method. Position estimator is composed of slip detector and linear velocity estimator. Both of them are based on the fact that dynamic characteristic of mobile robot in slippery environment is different from the case without slip. To find out the dynamic relation among driving torque, angular acceleration of driving wheel and linear acceleration of mobile robot, accelerometer is used for measuring acceleration of mobile robot and neural network is used for dynamic system identifier in slippery environment.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 신호처리소사이어티 추계학술대회 논문집
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• pp.287-290
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• 2003

In recent years, one of the main trends of GIS is to construct and provide realistic and human-perceptible information of spatial object using video data. The rapid progress of wireless mobile technology makes the multimedia source using video data possible on mobile environment. Instead of traditional map-based service, video-based location services, that provide video data as location context, would be of interest in connection with various mobile applications requiring location service, such as telematics, LBS, etc. In this paper, we present the location service system using geo-referenced video on wireless mobile environment.

• 수산해양기술연구
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• 제39권1호
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• pp.77-83
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• 2003

Autonomous mobile robots based on the Web have been already used in public places such as museums. There are many kinds of problems to be solved because of the limitation of Web and the dynamically changing environment. We present a methodology for intelligent mobile robot that demonstrates a certain degree of autonomy in navigation applications. In this paper, we focus on a mobile robot navigator equipped with neuro-fuzzy controller which perceives the environment, make decisions, and take actions. The neuro-fuzzy controller equipped with collision avoidance behavior and target trace behavior enables the mobile robot to navigate in dynamic environment from the start location to goal location. Most telerobotics system workable on the Web have used standard Internet techniques such as HTTP, CGI and Scripting languages. However, for mobile robot navigations, these tools have significant limitations. In our study, C# and ASP.NET are used for both the client and the server side programs because of their interactivity and quick responsibility. Two kinds of simulations are performed to verify our proposed method. Our approach is verified through computer simulations of collision avoidance and target trace.

• 한국통신학회논문지
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• 제39B권2호
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• pp.102-113
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• 2014

현재의 통신 및 네트워크 환경은 기존의 유선 인터넷에서 무선 및 모바일 기반으로 빠르게 움직이고 있으며 환경의 변화는 비즈니스 방법에도 많은 영향을 미치고 있다. 많은 기업들은 제품의 경쟁력확보를 위해 모바일 비즈니스 도입을 적극 추진하고 있으며, 효율적이고 안정적인 모바일 솔루션을 필요로 하고 있다. 그러나 최적의 모바일 컴퓨팅환경을 구축할 수 있는 방법과 기존의 업무프로세스 및 방대한 양의 데이터베이스를 어떻게 활용할 것인가에 대한 방안이 요구된다. 본 논문에서는 유선 상에서 운용되는 다양한 전산자원을 무선 LAN과 이동전화망, 모바일 디바이스로 연동할 수 있는 모바일 비즈니스 구축 지원 도구인 모바일 미들웨어 시스템을 구현하고자 한다. 이를 위해 일반기업에서 구축된 기간업무를 쉽고, 빠르게 모바일 환경으로 확장 시키는 강력한 무선 데이터 접근 도구를 제공한다. 제안 솔루션을 산업 현장에 적용 시 기존의 비즈니스 로직 및 자원의 변경 없이 경제적으로 레거시 업무 프로세스를 모바일 환경으로 변환 할 수 있다.

• 디지털융복합연구
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• 제11권5호
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• pp.187-199
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• 2013

스마트폰의 보급으로 모바일 환경으로의 변화는 모바일 시대라는 전환기를 가져왔다. 스마트 모바일 오피스는 바로 이러한 스마트폰이라는 새로운 모바일 환경과 소셜 미디어가 결합된 형태이다. 스마트폰을 이용한 모바일오피스 환경 구축은 스마트폰 시장의 활성화를 가져왔으며, 고객관리를 위한 CRM구축은 새로운 요구사항으로 대두되고 있다. 그러나, 현행 정보시스템 감리 기준만으로는 스마트 모바일 오피스 환경에서의 CRM 구축을 위한 감리에 적용하기에는 점검분야나 점검항목이 부족한 현실이다. 따라서, 본 논문에서는 스마트모바일 오피스 환경에서의 CRM 시스템 구축을 감리를 위한 모델을 제안하였다. CRM 구축에서 감리 영역 및 점검 항목들을 제안하였으며, 도출된 감리영역, 점검항목이 스마트 모바일 오피스 환경에서의 CRM 구축 감리의 목적에 부합되는지를 설문조사를 통하여 제안한 모델의 적합성을 검증하였으며, 검증결과 보통이상 만족도를 가지는 것으로 나타나 적합하다는 결론이 도출되었다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제10권4호
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• pp.281-286
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• 2010

We propose a space and time based sensor fusion method and a robust landmark detecting algorithm based on sensor fusion for mobile robot navigation. To fully utilize the information from the sensors, first, this paper proposes a new sensor-fusion technique where the data sets for the previous moments are properly transformed and fused into the current data sets to enable an accurate measurement. Exploration of an unknown environment is an important task for the new generation of mobile robots. The mobile robots may navigate by means of a number of monitoring systems such as the sonar-sensing system or the visual-sensing system. The newly proposed, STSF (Space and Time Sensor Fusion) scheme is applied to landmark recognition for mobile robot navigation in an unstructured environment as well as structured environment, and the experimental results demonstrate the performances of the landmark recognition.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.813-820
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• 2008

We have developed inventory database program which is available in the mobile PC. The mobile PC is convenient in terms of portability, data input, modification, practicality of various program and data confirmation in site. By utilizing the inventory database program in mobile PC, we are able to complete database in site. Then, database is converted into the Hangul document and Excel worksheet. Also, based on the above procedure, effective management and utilization of inventory on cut-slope can be achieved.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2004년도 춘계학술대회 학술발표 논문집 제14권 제1호
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• pp.139-143
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• 2004

Lee et al have proposed a framework for the linguistic map-based navigational planning of a mobile robot on dynamic environment and provided simulation results applied it to the static environment[1], In this paper, we extends the navigational planning of a mobile robot into dynamic environment. There are two kinds of dynamic obstacles： (1) Time-obstacles that change condition of obstacles with time. (2) Space-obstacles that move their position with time. We propose an algorithm which a mobile robot identifies and avoids the two kinds of dynamic obstacles. The proposed algorithm consists of two stages： (1) The fuzzy logic-based perception stage which identifies the dynamic obstacles around a mobile robot by using sensory data and fuzzy rules, (2) The planning stage which plans the path to goal by avoiding the dynamic obstacles[2-6]. We provide computer simulation results for a mobile robot in order to show the validity of the proposed algorithm.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권9호
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• pp.3384-3400
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• 2021

With the advent of the data era, people pay much more attention to data corruption. Aiming at the problem that the majority of existing schemes do not support corruption detection of ciphertext data stored in cloud environment, this paper proposes a data corruption detection scheme based on ciphertexts in cloud environment (DCDC). The scheme is based on the anomaly detection method of Gaussian model. Combined with related statistics knowledge and cryptography knowledge, the encrypted detection index for data corruption and corruption detection threshold for each type of data are constructed in the scheme according to the data labels; moreover, the detection token for data corruption is generated for the data to be detected according to the data labels, and the corruption detection of ciphertext data in cloud storage is realized through corresponding tokens. Security analysis shows that the algorithms in the scheme are semantically secure. Efficiency analysis and simulation results reveal that the scheme shows low computational cost and good application prospect.