• Journal of Institute of Control, Robotics and Systems
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• v.16 no.5
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• pp.498-509
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• 2010

In this paper, a waypoint guidance law Line Tracking algorithm is designed for testing an Unmanned Airship. In order to verify, we develop an autonomous flight control and test system of unmanned airship. The flight test system is composed FCC (Flight Control Computer), GCS (Ground Control System), Autopilot & Guidance program, GUI (Graphic User Interface) based analysis program, and Test Log Sheet for the management of flight test data. It contains flight test results of single-path & multi-path following, one point continuation turn, LOS guidance, and safe mode for emergency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.8
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• pp.1622-1631
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• 1997

A 3-stages Active Microstrip Phased Array Antenn(AMPAA) is implemented using Injection-Locking Coupled Oscillators(ILCO). The AMPAA is a beam scanning active antenna with capability of electrical scanning by frequency varation of ILCO. The synchronization of resonance frequencies in array elements is occured by ILCO, and the ILCO amplifies the injection signal and functions as a phase shifter. The microstrip ptch is operated as a radiation element. The unilateral amplifier is a mutual coupling element of AMPAA, eliminates the reverse locking signal and controls the locking bandwidth of ILCO. The possibility of Monolithic Microwave Integrated Circuits(MMIC) of T/R module is proposed by simplified and integrated fabrication process of AMPAA. The 0.75.$lambda_{0}$ is fixed for a mutual coupling space to wide the scanning angle and minimize the multi-mode. The AMPAA has beam scanning angle of 31.4.deg., HPBW(Half Power Beam Widths) of 26.deg., directive gain of 13.64dB and side lobe of -16.5dB were measured, respectively.

• Journal of the Optical Society of Korea
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• v.6 no.2
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• pp.27-32
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• 2002

An integrated optical 2$\times$2 add/drop multiplexer in X-cut, Y-propagating LiNbO$_3$ has been demonstrated. The device consists of passive polarization splitters and acousto-optical mode converters with weighted coupling utilizing tapered acoustical directional couplers; their specific design and properties are discussed. The insertion loss has been measured to be about -8.16 ㏈ and -8.6 ㏈ for TE and TM polarizations, respectively. The device shows a 3 ㏈ bandwidth of 2.3 nm, a tuning rate 8.34 nm/MHz around λ = 1554 nm, and a sidelobe suppression of about 14.5 ㏈. Optimum operation is achieved with a RF drive power of about 43 ㎽. Multi-wavelength operation has been demonstrated.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1996.10a
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• pp.142-147
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• 1996

For prediction and control of sound, acoustic systems must be modeled. Because sound systems like exhaust systems are very difficult to calculate mathematically, this study presents a method to determine experimentally the order of poles by transfer function. When designing a control system by traditional methods the exact model order and coefficient of the system to be controlled must be determined. But in acoustic systems, where systems to be controlled are very complex, mathematical interpretation is almost always impossible. Therefore transversal filters using trial and error methods to determine model order of a system are used to design a system. Compared to mathematical models with poles, transversal filters, in which the model order becomes relatively large, have the disadvantage of prolonged processing time and marked time delay. This study presents a method to determine experimentally the order of poles in a system model with poles and zeroes. Also, the validity of this method was verified mathematically and confirmed by application in general simple models and acoustic tube simulators.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.12
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• pp.1270-1277
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• 2008

For designing intensity modulation type optical microphone, the irradiance distribution which can be applied to inclined-cut geometrical configuration is suggested. The model is important in analysis of response characteristics for intensity modulation type optical microphone. To overcome low sensitivity problem in intensity modulation type optical microphone, inclined-cut optical fiber is considered here. Based on optical geometry, the inclined-cut optical fiber sensor is designed and fabricated. The experiments are carried out to evaluate sensor performance.

• Journal of Advanced Information Technology and Convergence
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• v.8 no.2
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• pp.147-157
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• 2018

In this study, we analyzed an outdoor visible light communication system and implemented it through a simulation. We designed a Reed-Solomon encoder, a variable interleaver structure, and set it to the Institute of Electrical and Electronics Engineers (IEEE) 802.15.7 PHY I specification mode. We also analyzed the performance of an additive white gaussian noise (AWGN) channel environment using a root-raised-cosine (RRC) filter, implemented a MATLAB simulation and analyzed its performance. The results showed a requirement for an additional signal-to-noise ratio (SNR) of approximately 1.5 dB in a 3-ray multipath visible light channel environment than in an AWGN environment.

• Archives of design research
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• v.11 no.1
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• pp.153-160
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• 1998

User, contents exchanged between user and computer system, and media are axes among the vanous factors related to multimedia interface. The points of contact resulted by three mam factors bring many design problems. User factor is most important among and its cognitive constraints become mam design principle for multi-modality features of multimedia. Because media could be understood differently depending on the level of information delivery, it is necessary that various characteristics and representation mode of media are clarified. This thesis develops design evaluation process that tells multimedia interface as a entity integrated with contents, media, and representation elements and assesses its sub elements whether they are correspond with design principal.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.11C
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• pp.1077-1087
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• 2003

In this paper, we proposed an architecture of a cryptosystem with various operating modes for the network security and implemented in hardware using the ASIC library. For configuring a cryptosystem, the standard block ciphers such as AES, SEED and 3DES were included. And the implemented cryptosystem can encrypt and decrypt the data in real time through the wired/wireless network with the minimum latency time (minimum 64 clocks, maximum 256 clocks). It can support CTR mode which is widely used recently as well as the conventional block cipher modes such as ECB, CBC and OFB, and operates in the multi-bit mode (64, 128, 192, and 256 bits). The implemented hardware has the expansion possibility for the other algorithms according to the network security protocol such as IPsec and the included ciphering blocks can be operated simultaneously. The self-ciphering mode and various ciphering mode can be supported by the hardware sharing and the programmable data-path. The global operation is programmed by the serial communication port and the operation is decided by the control signals decoded from the instruction by the host. The designed hardware using VHDL was synthesized with Hynix 0.25$\mu\textrm{m}$ CMOS technology and it used the about 100,000 gates. Also we could assure the stable operation in the timing simulation over 100㎒ using NC-verilog.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.2
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• pp.144-151
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• 2022

In this paper, a 1.5V 256kb eFlash memory IP with low area DC-DC converter is designed for battery application. Therefore, in this paper, 5V NMOS precharging transistor is used instead of cross-coupled 5V NMOS transistor, which is a circuit that precharges the voltage of the pumping node to VIN voltage in the unit charge pump circuit for the design of a low-area DC-DC converter. A 5V cross-coupled PMOS transistor is used as a transistor that transfers the boosted voltage to the VOUT node. In addition, the gate node of the 5V NMOS precharging transistor is made to swing between VIN voltage and VIN+VDD voltage using a boost-clock generator. Furthermore, to swing the clock signal, which is one node of the pumping capacitor, to full VDD during a small ring oscillation period in the multi-stage charge pump circuit, a local inverter is added to each unit charge pump circuit. And when exiting from erase mode and program mode and staying at stand-by state, HV NMOS transistor is used to precharge to VDD voltage instead of using a circuit that precharges the boosted voltage to VDD voltage. Since the proposed circuit is applied to the DC-DC converter circuit, the layout area of the 256kb eFLASH memory IP is reduced by about 6.5% compared to the case of using the conventional DC-DC converter circuit.

• Journal of the Institute of Convergence Signal Processing
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• v.8 no.1
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• pp.58-62
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• 2007

Digital communication is important for reliability and mobilization of the multi-channel communication systems. Transmitting and receiving data for the mobilization should be possible in anywhere and in anytime. And this system must be designed light weight small size and low power. One are essential technology for implementing the mobile wireless communication system on the age of ubiquotos. Requirements in constructing such communication field are followings. At first data transmitting and receiving should be carried out by a simple command. Second, the device should be designed as hand-hold type and low power consumption. Third, data communication should be reliable. As one of examples, car to car system which is popular in the market is introduced here, All traffic information in highway is transmitted from one car to another by using this system which can prevent possible traffic accident. This paper shows the design of a digital data communication system with CC1020 chip. This CC1020 makes easy frequency selection and easy switch from the transmit mode to the receive mode by simple setting of a memory register in the chip. The transmit power of this system is designed 10dBm and its communication range is about 100m. The power supplied this system is 3V considered as low power. The sleep mode can be easily entered during transmit mode or receive mode. We shows the program algorithm of CC1020 and interface circuit between MCU and CC1020. We shows the Photo of the CC1020 Module and Atmega128 Module.. We analysed the receiver rate with this system.