• Journal of Information Processing Systems
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• 제13권2호
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• pp.417-427
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• 2017

Power allocation is an important factor for cognitive radio networks to achieve higher communication capacity and faster equilibrium. This paper considers power allocation problem to each cognitive user to maximize capacity of the cognitive systems subject to the constraints on the total power of each cognitive user and the interference levels of the primary user. Since this power control problem can be formulated as a mixed-integer nonlinear programming (NP) equivalent to variational inequality (VI) problem in convex polyhedron which can be transformed into complementary problem (CP), we utilize modified projection method to solve this CP problem instead of finding NP solution and give a power control allocation algorithm with a subcarrier allocation scheme. Simulation results show that the proposed algorithm performs well and effectively reduces the system power consumption with almost maximum capacity while achieve Nash equilibrium.

• 기술사
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• 제33권4호
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• pp.17-26
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• 2000

This study has been done to make a practical suggestion in figuring out required size of electricity power facility in preparation for reunion of Korean Peninsula, estimated based on capacity increase and demand changes in the past. In making the suggestion, balanced development of South and North Korea Economy, recovery of existing power facilities, and construction of new power facilities were taken into consideration. As an alternatives, study result of power system interconnections in Korean Peninsula and/or in North-East Asia Region, PEACE Network, is suggested with a cooperation scheme of information and communications technology as an extra advantage. Concluded a cooperation of electric power system and information & communications technology in the peninsula is expected to be a great opportunity in developing electric power economy, maintaining clear environment, improving security of power supply in the region, and in reunion of Korean Peninsula and peace in the world.

• 한국위성정보통신학회논문지
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• 제11권1호
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• pp.46-50
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• 2016

The adaptive power control of Code Division Multiple Access (CDMA) systems for communications between User Equipments (UEs) with a link-budget based Signal-to-Interference Ratio (SIR) estimate which has distance information is applied to three inner loop power control algorithms. The speed estimation performances of these algorithms with their consecutive Transmit-Power-Control (TPC) ratios are compared to each other, and it is concluded that the speed can be estimated using the TPC ratio information of Consecutive TPC Ratio Step-size Closed Loop Power Control (CS-CLPC) and Fixed Step-size Power Control (FSPC).

• Journal of information and communication convergence engineering
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• 제15권4호
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• pp.237-243
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• 2017

This paper presents an analysis of the electromagnetic interference of a heterogeneous power bus where electromagnetic bandgap (EBG) cells are irregularly arranged. To mitigate electrical-noise coupling between high-speed circuits, the EBG structure is placed between parallel plate waveguide (PPW)-based power buses on which the noise source and victim circuits are mounted. We examine a noise suppression characteristic of the heterogeneous power bus in terms of scattering parameters. The characteristics of the dispersion and scattering parameters are compared in the sensitivity analysis of the EBG structure. Electric field distributions at significant frequencies are thoroughly examined using electromagnetic simulation based on a finite element method (FEM). The noise suppression characteristics of the heterogeneous power bus are demonstrated experimentally. The heterogeneous power bus achieves significant reduction of electrical-noise coupling compared to the homogeneous power buses that are adopted in conventional high-speed circuit design. In addition, the measurements show good agreement with the FEM simulation results.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.58-58
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• 2002

Recently Many technologies of the P.L.N (Power Line Network) are introduced for an efficient communication. P.L.N transmits information using power line channel. A medical information transmission system is proposed in this paper for the effective transmission. The Power Line Networks have an advantage in low cost because it uses existent power line. It can be easily applied anywhere that a power line socket is available. But the power line channel is very noisy, because many electronic devices in generate electronic noise in modulated signals. This problem should be considered carefully in the design of medical information transmission system using P.L.N. The proposed system can be applied...I propose a telemedicine system using the power line network.

• 정보통신설비학회논문지
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• 제10권2호
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• pp.74-79
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• 2011

The goal of this research is to reduce dynamic and static power consumption for a low power cache system. The proposed cache can achieve a low power consumption by using a drowsy and a way prediction mechanism. For reducing the static power, the drowsy technique is used at 4-way set associative cache. And for reducing the dynamic energy, one among four ways is selectively accessed on the basis of information in the Way-Line Prediction Unit (WLPU). This prediction mechanism does not introduce any additional delay though prediction misses are occurred. The WLPU can effectively reduce the performance overhead of the conventional drowsy caching by waking only a drowsy cache line and one way in advance. Our results show that the proposed cache can reduce the power consumption by about 40% compared with the 4-way drowsy cache.

• JSTS:Journal of Semiconductor Technology and Science
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• 제7권4호
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• pp.274-280
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• 2007

This paper demonstrates an efficiency improvement of the class E power amplifier (PA) by tuning-out the input capacitance ($C_{IN}$) of the power HBT with a shunt inductance. In order to obtain high output power, the PA needs the large emitter size of a transistor. The larger the emitter size, the higher the parasitic capacitance. The parasitic $C_{IN}$ affects the distortion of the voltage signal at the base node and changes the duty cycle to decrease the PA's efficiency. Adopting the L-C resonance, we obtain a remarkable efficiency improvement of as much as 7%. This PA exhibits output power of 29 dBm and collector efficiency of 71% at 1.9 GHz.

• Journal of Electrical Engineering and Technology
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• 제8권5호
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• pp.1212-1220
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• 2013

In general, for a large power system like DC distribution system for buildings, several power converters are modularized for parallel operation. However, in parallel operation, inconsistency of parameters in each module causes circulating current in the whole system. Circulating current is directly related to loss, and, therefore, it is most important for the safety of the power system to supply the suitable current to each module. This paper proposes a control method to reduce circulating current caused during parallel operation. Accordingly, the validity of parallel operation system including response characteristics and normal state was verified by simulation and experiment result.

• Journal of information and communication convergence engineering
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• 제10권1호
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• pp.78-84
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• 2012

This paper presents a branch prediction algorithm and a 4-way set-associative cache for performance improvement of an embedded RISC core and a clock-gating algorithm with observability don’t care (ODC) operation to reduce the power consumption of the core. The branch prediction algorithm has a structure using a branch target buffer (BTB) and 4-way set associative cache that has a lower miss rate than a direct-mapped cache. Pseudo-least recently used (LRU) policy is used for reducing the number of LRU bits. The clock-gating algorithm reduces dynamic power consumption. As a result of estimation of the performance and the dynamic power, the performance of the OpenRISC core applied to the proposed architecture is improved about 29% and the dynamic power of the core with the Chartered 0.18 ${\mu}m$ technology library is reduced by 16%.

• 한국통신학회논문지
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• 제35권11A호
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• pp.1038-1044
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• 2010

무선 통신 환경에서 간섭은 성능을 악화 시키는 요소이다. Han-Kobayashi 방식은 간섭의 영향을 줄이기 위해서 전송하는 신호를 개인신호와 공용신호로 분리하여 전송하고 수신기에서는 간섭 사용자의 공용신호를 제거하므로써 부분적으로 간섭을 제거한다. 본 논문에서는 개인신호만 전송할 때에 필요한 신호대 잡음비를 이용하여, 개인신호와 공용신호에 최적으로 전력을 할당하는 간단한 방법을 제안한다. 시뮬레이션을 통해서 제안하는 전력 할당 방법이 전수조사를 통한 기법의 성능에 근접함을 확인한다.