• International Journal of Aeronautical and Space Sciences
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• 제12권3호
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• pp.252-259
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• 2011

This paper is focused on dynamic modeling and control system design as well as vision based collision avoidance for multi-rotor unmanned aerial vehicles (UAVs). Multi-rotor UAVs are defined as rotary-winged UAVs with multiple rotors. These multi-rotor UAVs can be utilized in various military situations such as surveillance and reconnaissance. They can also be used for obtaining visual information from steep terrains or disaster sites. In this paper, a quad-rotor model is introduced as well as its control system, which is designed based on a proportional-integral-derivative controller and vision-based collision avoidance control system. Additionally, in order for a UAV to navigate safely in areas such as buildings and offices with a number of obstacles, there must be a collision avoidance algorithm installed in the UAV's hardware, which should include the detection of obstacles, avoidance maneuvering, etc. In this paper, the optical flow method, one of the vision-based collision avoidance techniques, is introduced, and multi-rotor UAV's collision avoidance simulations are described in various virtual environments in order to demonstrate its avoidance performance.

• 한국지능시스템학회논문지
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• 제22권5호
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• pp.669-674
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• 2012

본 논문은 아이폰을 사용하여 WiFi 통신을 기반으로 이동로봇을 원격 제어하는 연구에 대하여 다룬다. 무선제어를 위하여 다음과 같은 세 가지 인터페이스를 제안 한다 : 기울기 모드, 방향 터치 모드, 조그셔틀 모드. 세 가지 인터페이스를 평가하기 위해 모니터에 그려진 궤적을 아이폰의 인터페이스를 사용하여 가상 로봇을 제어 하였다. 세 가지 인터페이스의 장단점을 분석하기 위해 표준편차와 오차가 시뮬레이션에서 분석되었다. 제안된 인터페이스는 추가비용이 별도로 필요한 무선 제어기를 휴대폰으로 대체하게 해준다. 실험의 결과로 제안된 인터페이스들이 원격 로봇 제어를 위해 효과적으로 사용될 수 있음을 보여준다.

• 대한인간공학회지
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• 제31권4호
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• pp.567-575
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• 2012

Objective: The aim of this study is to get an optimal mental model by investigating user's natural behavior for controlling smart TV by mid-air gestures and to identify which factor is most important for controlling behavior. Background: A lot of TV companies are trying to find simple controlling method for complex smart TV. Although plenty of gesture studies proposing they could get possible alternatives to resolve this pain-point, however, there is no fitted gesture work for smart TV market. So it is needed to find optimal gestures for it. Method: (1) Eliciting core control scene by in-house study. (2) Observe and analyse 20 users' natural behavior as types of hand-held devices and control scene. We also made taxonomies for gestures. Results: Users' are trying to do more manipulative gestures than symbolic gestures when they try to continuous control. Conclusion: The most natural way to control smart TV on the remote with gestures is give user a mental model grabbing and manipulating virtual objects in the mid-air. Application: The results of this work might help to make gesture interaction guidelines for smart TV.

• Journal of Power Electronics
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• 제10권6호
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• pp.611-620
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• 2010

This paper presents a new architecture, called "Power Electronics Remote Wiring and Measurement Laboratory (PermLAB)", that translates a common gateway interface (CGI) string from a remote web user to a web server connected to a 3-dimension switching matrix board, can be used to switch on and off, and to control a cluster of instruments and components. PermLAB addresses real-time connection, switching, and data acquisition over the Internet instead of using simulated data. A software procedure uses a signature system to identify each instrument and component in a complex system. The Web-server application is developed in HTML, JavaScript and Java, and in C language for the CGI interface, which resides in a controller portion of LabVIEW. The LabVIEW software fully integrates the Web sever, LabVIEW data acquisition boards and controllers, and the 3-dimensional switching matrix board. The paper will analyze a half-wave rectifier (AC - DC converter) circuit connected over the Internet using the PermLAB. PermLAB allows students to obtain real data by real-time wiring of real circuits in the laboratory using a "virtual breadboard" on the Web. The software for the Web-based 3-dimensional system is flexible, portable, can be integrated into many laboratory applications or expanded, and easily accessible worldwide.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권11호
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• pp.5404-5424
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• 2018

This work is mainly focused on two major topics in cloud platforms by using OpenStack as a case study: management and provisioning of resources to meet the requirements of a service demanded by remote end-user and relocation of virtual machines (VMs) requests to offload the encumbered compute nodes. The general framework architecture contains two subsystems: 1) An orchestrator that allows to systematize provisioning and resource management in OpenStack, and 2) A resource utilization based subsystem for vibrant VM relocation in OpenStack. The suggested orchestrator provisions and manages resources by: 1) manipulating application program interfaces (APIs) delivered by the cloud supplier in order to allocate/control/manage storage and compute resources; 2) interrelating with software-defined networking (SDN) controller to acquire the details of the accessible resources, and training the variations/rules to manage the network based on the requirements of cloud service. For resource provisioning, an algorithm is suggested, which provisions resources on the basis of unused resources in a pool of VMs. A sub-system is suggested for VM relocation in a cloud computing platform. The framework decides the proposed overload recognition, VM allocation algorithms for VM relocation in clouds and VM selection.

• 인터넷정보학회논문지
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• 제22권5호
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• pp.27-33
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• 2021

With the broad adoption of the Internet of Things (IoT) in a variety of scenarios and application services, management and orchestration entities require upgrading the traditional architecture and develop intelligent models with ultra-reliable methods. In a heterogeneous network environment, mission-critical IoT applications are significant to consider. With erroneous priorities and high failure rates, catastrophic losses in terms of human lives, great business assets, and privacy leakage will occur in emergent scenarios. In this paper, an efficient resource slicing scheme for optimizing federated learning in software-defined IoT (SDIoT) is proposed. The decentralized support vector regression (SVR) based controllers predict the IoT slices via packet inspection data during peak hour central congestion to achieve a time-sensitive condition. In off-peak hour intervals, a centralized deep neural networks (DNN) model is used within computation-intensive aspects on fine-grained slicing and remodified decentralized controller outputs. With known slice and prioritization, federated learning communications iteratively process through the adjusted resources by virtual network functions forwarding graph (VNFFG) descriptor set up in software-defined networking (SDN) and network functions virtualization (NFV) enabled architecture. To demonstrate the theoretical approach, Mininet emulator was conducted to evaluate between reference and proposed schemes by capturing the key Quality of Service (QoS) performance metrics.

• International Journal of Computer Science & Network Security
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• 제21권8호
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• pp.111-118
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• 2021

Banking systems are sensitive to data privacy since users' data, if not well protected, may be used to perform fake transactions. Blockchains, public and private, are frequently used in such systems thanks to their efficiency and high security. Public blockchains fail to fully protect users' data, despite their power in the accuracy of the transactions. The private blockchain is better used to protect the privacy of the sensitive data. They are not open and they apply authorization to login into the blockchain. However, they have a lower security compared to public blockchain. We propose in this paper a hybrid public-private architecture that profits from network virtualization. The main novelty of this proposal is the use of network virtualization that helps to reduce the complexity and efficiency of the computations. Simulations have been conducted to evaluate the performance of the proposed solution. Findings prove the efficiency of the scheme in reducing complexity and enhancing data privacy by guarantee high security. The contribution conducted by this proposal is that the results are verified by the centralized controller that ensures a correct validation of the resulted blockchains. In addition, computation complexity is to be reduced by profiting from the cooperation performed by the virtual agents.

• 한국산업융합학회 논문집
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• 제24권6_2호
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• pp.937-946
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• 2021

The floating crane is used to lift the heavyweight on the ocean. The floating crane has a winch system for lifting the heavyweight and the system is controlled by the winch control system. The heavyweight is lifted safely by control of the winch control system. Before the make the control system and controller, there are many restricted conditions to test and validate at design and development steps. In order to solve the problems, commonly use the HILS (Hardware-In-the-Loop-Simulation). HILS is the method of test and validation for the hardware control system. It can be composed of the control system in hardware with surrounding environments which is a virtual model. In this study, we developed the winch system model for HILS of the 150t winch control system in a floating crane. Through this simulation and winch model, it can be applied to HILS for the winch control system.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2020년도 제61차 동계학술대회논문집 28권1호
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• pp.153-154
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• 2020

기존 VR컨트롤러는 현손에 별도의 컨트롤러를 들고 조작해야만 해왔다. 이는 현실감을 느끼기 위한 시각적인 요소를 충족시켰음에도 몰입도를 떨어뜨리는 요소이다. 본 연구에서는 현실감을 더욱 증가 시키는 것을 전제로 뇌파를 이용한 VR컨트롤러 기술을 적용하고자 한다. 현재 대중화 되어 있는 VR 장치들을 보면 움직이는 의자, 보행을 위한 장치, 캐릭터 조종을 위한 손에 쥐는 컨트롤러 등을 사용하고 있다. 이러한 장치들은 가상현실을 더욱 현실처럼 느끼기 위한 보조적인 장치들이지만 장치를 설치하기 위한 공간을 많이 차지하기 때문에 일반 가정에서는 잘 사용하지 않는다. 또한 손에 있는 컨트롤러로 가상 현실속의 동작을 구현하다 보니 아무리 내 눈앞에 보이더라도 '단순한 게임이다'라는 생각을 가지고 있어 몰입도가 떨어질 수밖에 없다. 본 논문은 이러한 문제점들을 개선하기 위해 기존의 VR컨트롤러 대신 뇌파입력을 적용한 '머신러닝을 통한 뇌파 VR컨트롤러' 기술을 제안한다. 기존의 VR컨트롤러와는 다르게 빅 데이터 처리기술인 머신러닝을 이용하여 뇌파 데이터를 처리하고 그 데이터들과 입력되는 뇌파 값을 비교하여 가상현실 속의 캐릭터의 동작을 제어할 수 있다.

• 드라이브 ㆍ 컨트롤
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• 제12권4호
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• pp.60-70
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• 2015

A front-end loader (FEL) mounted on an agricultural tractor is one of the most commonly used implements for farm work. However, when the tractor carries material using the bucket attached to the FEL on a sloping ground, the materials can spill or roll back over the operator due to the tilted body, thereby requiring the bucket surface to remain level at a constant value regardless of varying slopes. In this study, an active system for controlling the angle of the FEL bucket on a tractor based on the real-time measurement of ground slopes was developed to enable the bucket to constantly remain level. A FEL simulator operated based on an electro hydraulic proportional valve (EHPV) was constructed in the laboratory to develop a proportional-integral-derivative (PID) controller forming a virtual electronic control unit (ECU) on the computer, which could automatically adjust the bucket angles depending on varying input angles while sending SAE-J1939 associated messages via CAN BUS to the EHPV. The different parameter values for the PID controller due to the gravity effect of the bucket were determined using a manual PID tuning method while assuming that the tractor travels on either an ascending slope or a descending slope. The developed PID control-based self-leveling system showed a mean of steady-state errors of within $1^{\circ}$ and a mean of delayed times of ~ 0.8s when the step input of $+20^{\circ}$ was given, implying that the developed system and control algorithm would be effective in maintaining the bucket angle at a certain value. Future studies include the improvement of the control algorithm to reduce such a time delay as well as the application of the developed algorithm to the FEL mounted on a tractor tested at a testing ground.