• Journal of National Security and Military Science
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• s.8
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• pp.351-381
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• 2010

Established on February 1st, 2010, The ROKN maritime task flotilla has a goal to successfully cope with North Korea and other potential threats. Unlike precedents of its kind, The ROKN maritime task flotilla is expected to concentrate more an far-sea strategies than coastal strategies. In such circumstances however, the existing maritime logistics systems have limitations upon which to utterly support the operation conception of the ROKN maritime task flotilla seven. To ensure it's efficiency, transformation of the systems is prerequisite. The purpose of this study is to deduce an adequate maritime logistics system for the ROKN maritime task flotilla by evaluating the limitation of the current system and foreseeing its performance necessary abilities to operate in the future. In order to do this, the study presented problems and the direction of development on the structural and behavioral sides. Fist, regarding problems in the structure of maritime logistics system, the investigation pronounced the need of improvement in mobile logistics support ability and its speed. In addition, for the behavioral side, the need of improvement in logistics cooperation system and self-maintenance ability was affirmed. For the development of an adequate maritime logistics system, the study suggested the amelioration in the operation of an adequate mobile logistics support platform and the speed of the logistics using high-speed transportation such as planes for the structural side. Moreover, for the behavioral side, it recommended th enhancement of logistics cooperation system including the nations that already imported th weapon system, amelioration of self-maintenance ability, and necessity to operate mobile maintenance group.

• Journal of Power System Engineering
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• v.2 no.3
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• pp.74-82
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• 1998

This paper presents a new approach to the design of speed and azimuth control of a mobile robot with two drive wheels. The proposed control scheme uses a Gaussian function as a unit function in the neural-fuzzy network and back propagation algorithm to train the neural-fuzzy network controller in the framework of the specialized learning architecture. It is proposed to a learned controller with two neural-fuzzy networks based on an independent reasoning and a connection net with fixed weights to simplify the neural-fuzzy network. The performance of the proposed controller can be seen by the computer simulation for trajectory tracking of the speed and azimuth of a mobile robot driven by two independent wheels.

• Proceedings of the KWS Conference
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• 2000.10a
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• pp.34-36
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• 2000

It is difficult to realize automation of welding of lattice type in shipbuilding and assembly processing of shipbuilding and steel structures. Usually, the welding parts of lattice type are welded manually. So there are limitations in continuous and stable quality controls and in increase in productivity because the welding quality depends on worker's skill. That is, automation in welding is necessary. This paper shows shows the development results of a moblie robot for welding of lattice type. Specially. algorithms for its mobile speed and seam tracking controls are introduced.

• Journal of the Ergonomics Society of Korea
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• v.29 no.4
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• pp.541-546
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• 2010

The gesture 'Flick' is the most fundamental and important part for efficient interactions in the touch screen that are being extensively applied to mobile phones. This study investigated users' satisfaction of the flick operation in representative touch phones, and measured their performances with established three measures: gap between finger and initial cursor, the number of moved lists per 0.2 seconds, and the number of moved lists after ten continuous flicks. The measurement was performed with high speed camera and motion analysis software. The flick movement in mobile phone with high users' satisfaction showed that the gap between finger and cursor positions was less and the speed reached high within 0.6 seconds quickly and then was drastically slow down. Especially, maximal and common time intervals between continuous flicks were measured with an experiment. Based on the evaluation and measurement, several design guidelines for efficient flick performances were suggested.

• Proceedings of the IEEK Conference
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• 2002.06c
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• pp.119-122
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• 2002

The paper proposed the intelligent inference method which keeps MV(Mobile vehicle) a little way off from men and makes it follow them using fuzzy controller Recognizing positions of MV and Men and distance between them was used to infer movement angle and speed of the MV with multi-ultrasonic sensor and USB camera The very important thing Is that the MV needs to obtain surrounding Information from the sensor and the camera, then It needs to represent those circumstances MV was controlled by inference from the speed and angle which are obtained from sensor and camera. Traveling simulation with a real MV was performed repeatedly to verify the usefulness of the fuzzy logic algorithm which was proposed in this paper. And a successful result of the experiment demonstrated the excellence of the fuzzy logic controller.

• Journal of Korean Society for Quality Management
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• v.32 no.2
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• pp.15-23
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• 2004

This study investigates the customer satisfaction based on the various levels of many factors such as age, sex, period, motive, preference between wired and mobile service, frequency, and time. Customer satisfaction is measured by 13 dimensions. MANOVA reveals that preference between wired and mobile commerce service, mobile service frequency, mobile e-mail service frequency, wired Internet usage frequency, and mobile Internet usage time have a significant effect on the overall satisfaction. Transmission speed, fare, and ease of operation of mobile Internet service turn out to be improved for better customer satisfaction, the IMT-2000 service in particular.

• International Journal of Contents
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• v.9 no.1
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• pp.11-17
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• 2013

Recently, online real-time web accessible mobile devices such as smartphones, tablet PCs and application services have been developing rapidly. Hospitals also need to adopt an efficient information system that can provide decent medical services under mobile computing environments to complete future medical services. This study proposes a system in which a doctor can examine a patient and make out a prescription in a ward on a real-time based on the current Order Communication Systems (OCSs) through mobile interfaces. The proposed system implements mobile web pages using HTML5, instead of a mobile app. Web processing speed can be enhanced using the web socket and web storage functions of HTML5.

• Journal of the Semiconductor & Display Technology
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• v.8 no.4
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• pp.53-58
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• 2009

A SMT mounter is a kind of equipment that mounts SMD parts quickly on the printed circuit board. By using linear motors, it is controlled with high speed and precision, which is similar to semi-conductor and display process equipment. It is necessarily used in an assembly process of an electronic device. Mobile devices such as a mobile phone and PDA are required to reduce mount areas due to the demands for high performance and small size. Hence, super small sized and complex mobile devices have been developed. To improve the productivity of the corresponding equipment, designs with large sized, high speed, and multidisciplinary functions have been consistently performed. Meanwhile, a design trend of large size and light-weight on SMT mounter causes a low natural frequency of systems and vibration problems at the high speed operation. In this paper, the dynamic characteristics of the SMD mounter system were investigated through a modal test and transmissibility test, and verified by finite element method. Also, various design improvement was performed to avoid the resonance phenomena.

• Journal of Electrical Engineering and Technology
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• v.9 no.1
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• pp.352-362
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• 2014

In this paper, a fuzzy logic controller is designed for a DC motor which can be used for navigation control of mobile robots. These mobile robots can be used for agricultural, defense and assorted social applications. The robots used in these fields can reduce manpower, save human life and can be operated using remote control from a distant place. The developed fuzzy logic controller is used to control navigation speed and steering angle according to the desired reference position. Differential drive is used to control the steering angle and the speed of the robot. Two DC motors are connected with the rear wheels of the robot. They are controlled by a fuzzy logic controller to offer accurate steering angle and the driving speed of the robot. Its location is monitored using GPS (Global Positioning System) on a real time basis. IR sensors in the robot detect obstacles around the robot. The designed fuzzy logic controller has been implemented in a robot, which depicts that the robot could avoid obstacle as well as perform its operation efficiently with remote online control.

• Journal of Communications and Networks
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• v.5 no.1
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• pp.25-32
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• 2003

4G mobile communication system requires the throughput of 10-100Mbps. Adaptive modulated OFDM system is promising technique for increasing the throughput. In the pilot symbol assisted high-speed packet transmission system, the data symbol duration is generally considered to be small compared to the coherence time. However, OFDM symbol duration is longer than the symbol duration of a single carrier system, so that the packet duration of the pilot symbol assisted high speed packet transmission system is long. In this case, the change of channel conditions is too fast to be accurately estimated by channel estimator at the receiver in high Doppler frequency, so that many errors occur during demodulation, especially with the data symbols at the end of each packet. In this paper, we consider the BER at various instantaneous $E_b/N_o$ that includes the demodulation errors in high Doppler frequency. When the coherence time is ten times longer than the duration of a single packet, the channel can be closely approximated as an AWGN channel. Otherwise, the approximation breaks down and the above-mentioned errors that occur during demodulation must be taken into consideration. In this paper, we propose the pilot symbol assisted high speed packet transmission system based on adaptive OFDM using a novel lookup table to consider the demodulated errors and evaluate the throughput performance.