• Transactions of the Society of Information Storage Systems
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• v.1 no.1
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• pp.67-72
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• 2005

This study proposes a design methodology to determine the optimum configurations of the optical flying head (OFH) for near-field recording systems. Since the OFH requires stricter static and dynamic characteristics of slider air-bearings within an optical tilt tolerance over the entire recording band, an optimum design to keep the focusing and tracking ability stable is essential. The desired flying characteristics considered in this study are to minimize the variation in flying height between the SIL and the disk from a target value, satisfying the restriction of the minimum flying height, to keep the pitch and roll angles within an optical tilt tolerance, and to ensure a higher air-bearing stiffness. Simulation results demonstrate the effectiveness of the proposed design methodology by showing that the static and dynamic flying characteristics of the optimally designed OFH are enhanced in comparison with those of the initial. The gap between the SIL and the disk can be kept at less than 100 nm even if the optical tilt tolerance of the SIL is considered.

• Journal of Power Electronics
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• v.16 no.1
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• pp.133-141
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• 2016

This paper focuses on the development of a Five-Level Flying-Capacitor Dual Buck Inverter (FLFCDBI) based on the main circuit of dual buck inverters. This topology has been described as not having any shoot-through problems, no body-diode reverse recovery problems and the half-cycle work mode found in the traditional Multi-Level Flying-Capacitor Inverter (MLFCI). It has been shown that the flying-capacitor voltages of this inverter can be regulated by the redundant state selection within one pole. The voltage balance of the flying-capacitors can be achieved by charging or discharging in the positive (negative) half cycles by choosing the proper logical algorithms. This system has a simple structure but demonstrates improved performance and reliability. The validity of this inverter is conformed through computer-aided simulation and experimental investigations.

• Transactions of the Society of Information Storage Systems
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• v.2 no.1
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• pp.65-70
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• 2006

In the information storage development, the trend of the storage device is to increase the recording density. Among such an effort, near-field probe recording is spotlighted as a method of high increasing recording density. For the successfully embodiment of storage device, the actuating mechanism of near-field probe is essentially designed. In this paper, we suggest the slider similar with conventional HDD and design the slider using near-field probe for the purpose of applying the slider in order to control gap between probe and media. The most important object of slider design is to guarantee the flying ability and stability. For achievement of these design objects, we perform two step of optimal design process. The media is supposed to model as random displacement, which is only considered roughness of disk surface. The design slider is analyzed with dynamic state in assumed media. At this process, the optimal model is confirmed to stable flying stability.

• 정보저장시스템학회:학술대회논문집
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• 2005.10a
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• pp.171-176
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• 2005

In the information storage development, the trend of the storage device is to increase the recording density. Among such an effort, near-field probe recording is spotlighted as a method of high increasing recording density. For the successfully embodiment of storage device, the actuating mechanism of near-field probe is essentially designed. In this paper, we suggest the slider similar with conventional HDDs and design the slider using near- field probe for the purpose of applying the slider in order to control gap between probe and media. The most important object of slider design is to guarantee the flying ability and stability. For achievement of these design objects, we perform two step of optimal design process. The media is mod! eled as random displacement, which is only considered roughness of disk surface. The design slider is analyzed with dynamic state in assumed media. At this process, the optimal model is confirmed to stable flying stability.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.5
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• pp.991-1000
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• 2019

The flying-disc game has started since 1940. It has been spreading rapidly in Korea since 2007, mainly in elementary schools. Additionally, as sports science has been developed, research on flying discs has been continued to build a monitoring system for technological improvement and efficiency. In this paper, we acquire information on the user's flying-disc using 9-axis motion sensor and GPS. Then we propose a method for wireless transmission using Bluetooth 5.0. Specifically, the HW platform was designed and implemented not only to monitor a real-time data but also to compare and analyze rotational speed, flight trajectory, and a count of disc rotation through post-processing.

• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.6
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• pp.484-489
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• 2020

This study proposes a new soft-switching three-level flying capacitor converter with low filter inductance. The proposed converter can achieve zero voltage switching (ZVS) turn-on of all switches by using auxiliary components La and Ca. It can also reduce filter inductance because the applied voltage of the filter inductor is decreased by using the flying capacitor. Furthermore, filter inductance can be reduced because the operating frequency of the filter inductor is doubled by the phase shifting between switches S3 and S4. The operation principle, design of passive components for ZVS turn-on, interleaving effects, and comparison of different topologies are presented. The experimental waveforms of a 1 kW two-phase interleaved converter prototype are provided to verify the validity of the proposed converter.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.5
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• pp.490-495
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• 2015

As flying robots are becoming popular, there are increased needs to use themforsuch purposes as parcel delivery, serving in restaurants, and stage performances. To control flying robots such as quad copters, localization is essential. In order to properly position flying robots, many techniques are in development, including IR (infra-red)-based systemswhich catch markers on a flying robot in order that it can position itself. However, this technique demonstrates only short coverage. Furthermore, localization from inertial sensors diverges as time passes. For this reason, this paper suggests a TWR (two-way ranging) based positioning technique. Despite the weaknesses in currently available TWR system, this paper suggests a self-positioning and outlier detection technique in order to provide reliable position information with a faster update rate. The self-positioning system sends a shorter message which reduces wireless traffic. By detecting and removing outlier measurements, a positioning result with better accuracy is acquired. Finally, this paper shows that the suggesting system detects outlierssequentially from less than half the number of anchors in localization system according to the degree of outlier in measurement and the noise level. By performing an outlier algorithm, better positioning accuracy is acquired as shown in the experimental result.

• Transactions of the Society of Information Storage Systems
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• v.5 no.2
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• pp.58-63
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• 2009

This paper describes the effects of slider behavior over patterned media. The flying characteristics of a slider over patterned media are different from slider flying behavior over conventional plane disk. In order to perform the most realistic simulation of slider flying characteristics over patterned disk surfaces, our simulation approach virtually distributes the grooves on the slider ABS instead of on the disk surface. Also, we define SSFA which is steady-state slider flying attitude. The results show that the more patterned size is small and height is large, the more increased SSFA is. Also if patterned distance is small, then SSFA is increased. In addition, we analyzed the effects of patterned shapes.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.899-902
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• 2005

언제, 어디서, 누구나 대용량 네트워크를 사용할 수 있는 유비쿼터스(ubiquitous) 시대가 다가오면서, 카메라가 장착되어 있고 무선 통신이 가능한 PDA, 웨어러블(wearable) 컴퓨터와 같은 휴대용장치가 가까운 미래에는 일상의 한 부분이 될 것이다. 이런 상황을 반영하듯, 휴대용 장치를 이용하여 실감형 게임(augmented game)을 수행하는 다양한 연구가 진행되어 왔다. 기존의 실감형 게임들은 전통적인 ‘backpack’ 시스템을 이용하거나 패턴마커(pattern marker)를 이용하였다. ‘backpack’ 시스템은 비싸고, 거추장스러우며, 사용하기 불편한 단점을 가지고 있으며, 패턴마커를 이용하면 미리 정한 장소에서만 게임을 즐길 수 있는 단점을 가지고 있다. 본 논문에서는 Flying Cake이라는 실감형 게임을 소개하며, 거추장스러운 장비 대신, 가볍고 휴대 가능한 PDA를 이용하여 게임을 수행하며, 실제 세계에서 가상의 물체를 접목할 위치를 지정하기 위해, 미리 정해져 있는 패턴마커 대신 얼굴 영역을 이용한다. Flying Cake은 연산자원이 부족한 PDA에서 실시간으로 얼굴 영역을 찾기 위해 스킨칼라(skin-color) 모델과 CAMShift 알고리즘을 이용하며, PDA상에서 카메라를 이용하여 실제 세계와 가상의 물체 사이의 상호작용을 제공하는 새로운 게임 패러다임(paradigm)을 통해 사용자에게 새로운 즐거움을 제공한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.12
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• pp.1942-1949
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• 2016

This paper proposed automatic path-tracing methods for Flying Disc Golf by adopting IoT comcepts at smart-marker. We tried to implement service system by making database. Smart-marker's configurations & roles are proposed. By making test-boards and adoption to various Flying Disc Golf games, the efficiency is proved. The positions and distances captured by the smart-marker are transferred to the smart-pole per each hole. The smart-pole captured them and transfers to web-server which is databased them. The result can be searched by web or smartphone in real time.