• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.9
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• pp.22-26
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• 1994

In this paper a method of designing FIR filters without digital arithmetic operationsi is persented. The filter coefficients are represented by resistors combined with a differential amplifier. With this method an FIR filter can be simply impemented without refering to complex digital arithmetic operations. Furthermore, in this scheme, no additional D/A converter is needed for D/A conversion. Spectral response response of a pulse shaping filter of 17 coefficients is shown as an illustration.

• 한국데이터정보과학회:학술대회논문집
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• 2002.06a
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• pp.1-4
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• 2002

• Proceedings of the IEEK Conference
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• 2002.06c
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• pp.189-192
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• 2002

This paper has been studied some security issues o( stream control transmission protocol and designed some functional requirement for IPsec and IKE to facilitate their use for securing SCTP. In particular, some additional support in the form of new ID type in IKE and some implementation choices in the IPsec processing to accomodate for the multiplicity of source and destination addresses associated with a single SCTP association.

• Proceedings of the IEEK Conference
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• 2000.06e
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• pp.73-76
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• 2000

We study the Chua oscillator circuit by considering a negative resistor as a characteristic parameter which controlled by the CdS(Cadmium Sulphide) cell. This is a new way to observe several chaotic phenomena with the same initial condition continuously. Since we can control the internal resistance of the CdS cell by an additional circuit, our autonomous chaotic oscillator circuit makes it possible to measure the voltage value continuously and automatically.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.5
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• pp.1-9
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• 1993

In this paper, we develop enhanced hypercube architectures and routing algorithms to realize arbitrary permutations in circuit switching. We prove that a hypercube is rearrangeable if one additional pair of links (one full-duplex communication line) is provided in only one dimesion of connections. We also prove that if each connection between two neighboring nodes consists of two pairs of links, the hypercube can handle two independent permutations simultaneously.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1991.10a
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• pp.199-202
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• 1991

Recent telecommunication technology trends have made possible the concept of Intelligent Network, which is expected to lead to additional revenues for both telecommunication administers as well as business service customers. In this paper international Korea Telecommunication Network configuration with special services are described and introducing the Intelligent Network Services into the international Korea Telecommunication Network in a phased manner is studied considering of interworking between international and domestic Intelligent Network services.

• Journal of Power Electronics
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• v.11 no.4
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• pp.507-511
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• 2011

This paper presents a single-switch buck converter with a ripple-free inductor current. In the proposed converter, the filter inductor current ripple is completely removed by utilizing an auxiliary circuit consisting of an additional winding of the filter inductor, an auxiliary inductor, and an auxiliary capacitor. Moreover, the ripple-free current characteristic is maintained under both light load and full load conditions. The theoretical analysis and performance of the proposed converter were verified with a 110W experimental prototype operating at a 107 kHz switching frequency.

• Journal of Power Electronics
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• v.11 no.1
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• pp.16-20
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• 2011

This paper presents a zero-voltage-switching (ZVS) boost converter using a coupled inductor. It utilizes an additional winding to the boost inductor and an auxiliary diode. The ZVS characteristic of the proposed converter reduces the switching losses of the active power switches and raises the power conversion efficiency. The principle of operation and a system analysis are presented. The theoretical analysis and performance of the proposed converter were verified with a 100W experimental prototype operating at a 107 kHz switching frequency.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2007.02a
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• pp.26-31
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• 2007

An ad hoc network is a collection of mobile nodes without any Infrastructure. However, ad hoc networks are vulnerable to attacks such as routing disruption and resource consumption; thus, routing protocol security is needed This paper proposes a secure and efficient routing protocol for mobile ad hoc networks, where only one-way hash function are used to authenticate nodes in the ROUTE REQUEST, while additional public-key cryptography is used to guard against active attackers disguising a node in the ROUTE REPLY.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2086-2088
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• 2002

This paper deals with an algebraic approach for unknown inputs observer by using Haar functions. In the algebraic UIO(unknown input observer) design procedure, coordinate transformation method is adopted to derive the reduced order dynamic system which is decoupled unknown inputs and Haar function and its integral operational matrix is applied to avoid additional differentiation of system outputs.