• 한국통신학회논문지
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• 제41권12호
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• pp.1925-1932
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• 2016

One of the major challenges in the design of wireless sensor network (WSN) is to reduce the energy consumption of sensor nodes for prolonging the network lifetime. In the sensor network, communication is the most energy consuming event. Therefore, most of the energy saving techniques conserve energy by adjusting different parameters of the trans-receiver. Among them, one of the promising methods is the transmission power control (TPC). In this paper, we investigated the effects of the link quality based TPC scheme employed to the IEEE 802.15.4 standard for energy saving. The simulation results demonstrated that the link quality based TPC scheme works effectively in conserving energy as compared to the conventional IEEE 802.15.4.

• 한국통신학회논문지
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• 제39C권1호
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• pp.72-81
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• 2014

최근 불규칙적인 전력 수요에 따른 수차례의 전력난에 의해, 양방향 통신을 이용하여 전력의 공급과 수요 정보를 실시간으로 교환함으로써 변동하는 전력 수요에 맞추어 효율적으로 전력을 공급할 수 있게 해주는 스마트 그리드의 도입의 필요성이 급속하게 높아지고 있다. 향후 국내에 스마트 그리드환경이 구축되면, 스마트 그리드 환경에서 얻을 수 있는 정보를 이용하여 서비스를 제공하는 third-party들 역시 활성화될 것이다. 본 논문에서는 스마트 그리드 환경이 구축된 가정에서 발생하는 가전기기 소비전력 패턴을 데이터 마이닝 기법을 이용하여 분석하고, 가족 유형을 분류하는 방법을 제안한다. 가족 유형을 분류하는 분류기를 만들기 위해서는 소비전력이 어떤 가족 유형에서 생성되었는지에 대한 데이터가 필요한데, 현실적으로 그러한 데이터를 수집하기는 힘들다. 따라서 본 연구에서는 가상의 데이터를 생성하기 위해 가족 유형에 따른 소비전력을 생성하는 시뮬레이터를 개발하고, 시뮬레이터에서 생성되는 소비전력 정보를 이용하여 가족 유형을 분류한다. 또한 본 논문에서 제안하는 기법이 향후 각 가구의 특성에 따른 맞춤형 서비스 또는 마케팅에 활용될 수 있는 가능성을 제시한다.

• 정보처리학회논문지C
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• 제17C권5호
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• pp.433-440
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• 2010

무선 센서 네트워크에서 에너지 효율성, 전송 지연 그리고 확장성은 중요한 요구사항이며, 특히 다수의 노드로 구성된 무선 센서 네트워크의 경우 네트워크 라이프타임 연장을 위해 제한된 배터리 전력 내에서 각 노드의 에너지 소비를 최소화 시켜야한다. 또한 전송률을 향상시키기 위해서는 각 센서 노드의 에너지 소비를 최소화하기 위한 효율적인 알고리즘과 에너지 관리 기술이 요구된다. 본 논문은 무선 센서 네트워크 환경에서 센서 데이터 전송을 위해 경로의 겹침이 없는 다중경로 프로토콜을 제안한다. 제안한 방법은 다중경로를 검색하고 라우팅 테이블에 다중경로를 추가시켜 센서 데이터 전송의 감소를 통해 네트워크 오버헤드를 최소화 시킨다. 제안한 라우팅 프로토콜은 각 노드의 에너지 소비를 최소화하고, 싱크 노드가 수신 강도 범위 내, 외부에 위치하더라도 센서 네트워크의 생명주기를 연장할 수 있다. 실제 데이터를 이용하여 현실 모델에 맞게 센서 네트워크를 구축하고 제안 기법의 타당성을 검증하며, 전체 에너지의 소비량을 평가한다.

• International Journal of Computer Science & Network Security
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• 제22권7호
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• pp.240-244
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• 2022

The common goals of designing a routing algorithm are not only to reduce control packet overhead, maximize throughput and minimize the end-to-end delay, but also take into consideration the energy consumption. Scalability is an important factor in designing an efficient routing protocol for wireless sensor networks (WSN's). Three metrics (power consumption, time of transmission and packet loss rate) are used in order to compare three routing protocols which are AODV, DSDV and LEACH.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권5호
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• pp.2433-2452
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• 2017

Recently, the pipeline-forwarding has been proposed as a new technique to resolve the end-to-end latency problem of the duty-cycle MAC protocols in Wireless Sensor Networks (WSNs). Some protocols based on this technique such as PMAC and PRI-MAC have shown an improvement not only in terms of reducing end-to-end latency but also in terms of reducing power consumption. In these protocols, however, the sensor nodes still waste a significant amount of energy for unnecessary idle listening during contention period of upstream nodes to check the channel activity. This paper proposes a new pipeline-forwarding duty-cycle MAC protocol, named RP-MAC (Reduced Pipelined duty-cycle MAC), which tries to reduce the waste of energy. By taking advantage of ACK mechanism and shortening the handshaking procedure, RP-MAC minimizes the time for checking the channel and therefore reduces the energy consumption due to unnecessary idle listening. When comparing RP-MAC with the existing solution PRI-MAC and RMAC, our QualNet-based simulation results show a significant improvement in term of energy consumption.

• 전기학회논문지
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• 제63권4호
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• pp.455-460
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• 2014

South Korea's power consumption is increasing every year. For stable electric power supply, more generation facilities are needed. But it is not easy to build nuclear power generation facilities, so provision of renewable energy is thought of as the solution. For the system's stable management, practical use of energy storing system is needed. Currently, pumping up electric power station is considered most useful. In this study, we have calculated the least amount of energy storing device by considering the renewable energy, HVDC, and change in power for the appliance of ESS in Jeju system, according to The 6th Basic Plan for Long-term Electricity Supply and Demand. Also we have calculated the amount of the battery and about the load equalizing effect to use battery as power storing device. Finally, we have calculated the reduction of electricity generation and the reduction of $CO_2$ emission with this study.

• Journal of Electrical Engineering and Technology
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• 제9권6호
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• pp.1795-1804
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• 2014

Owing to the reduction in the peak power of a DC railway subsystem, many studies on energy storage system (ESS) applications have received attention. Each application focuses on improving the efficiency and addressing regulation issues by utilizing the huge regenerative energy generated by braking-phase vehicles. The ESS applications are widely divided into installation on a vehicle or in a substation, depending on the target system characteristics. As the main purpose of the ESS application is to reduce the peak power of starting-phase vehicles, an optimized ESS utilization can be achieved by the operating at the highest peak power section. However, the weight of an entire vehicle, including those of the passengers, continuously changes during operation; thus, considering the total power consumption and the discharging point is difficult. As a contribution to the various storage device algorithms, this study deals with ESS on board vehicles and introduces an ESS operating plan for peak-power reduction by investigating the weight of a train on a real-time basis. This process is performed using a train-performance simulator, and the simulation accuracy can be increased because the weight in each phase can be adopted in the simulation.

• 한국전기전자재료학회논문지
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• 제30권10호
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• pp.672-676
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• 2017

Electrical energy is playing an increasingly vital role as the primary energy source in everyday life. With the increase in electric power consumption, power facilities are under an increasing stress and must operate at a high capacity. Consequently, the demand for electric power cables in power transmission and distribution lines is rapidly increasing. Underground distribution lines have been steadily replacing the aboveground lines owing to the increase in electric power demand and the need to increase the supply voltage. In addition to line damage, worker safety is of primary concern in this type of underground infrastructure. In this study, to improve the safety of workers dealing with underground transmission lines, we analyzed the electromagnetic field generated around the distribution line and determined the basic criteria for developing a device that can detect a live underground line.

• 한국태양에너지학회 논문집
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• 제28권5호
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• pp.72-77
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• 2008

The purpose of this paper is to explain the real characteristics of generation system of large scale power system of high voltage the grid connected PV power system for electricity industry. Main system is made up PCS in the class 150kVA. and we studied commercial operation in Korea-Western Power Company,(Tae-An headquarter) with the capacity of module is 122.5 $kW_p$. On the average, power plant utilities' utilization is 12.71 percent and consumption rate is 6.66 percent. We operated normally since 25th, August 2005 without any other problems.

• 대한전기학회논문지:전력기술부문A
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• 제49권6호
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• pp.280-288
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• 2000

Recently, there has been growing interest in utilizing cogeneration(COGN) systems with a high-energy efficiency due to the increasing energy consumption and the lacking of energy resource. But an insertion of COGN system to existing power distribution system can cause several problems such as voltage variations, harmonics, protective coordination, increasing fault current etc, because of reverse power of COGN, especially in protective coordination. A study on a proper coordination with existing one is being required. The existing power distribution system is operated with radial type by one source and protection system is composed based on unidirectional power source. But an Insertion of COGN system to power distribution system change existing unidirectional power source system to bidirectional power source. Therefore, investigation to cover whole field of power distribution system must be accomplished such as changing of protection devices rating by increasing fault current, reevaluation of protective coordination. In this paper, simulation using PSCAD/EMTDC was accomplished to analyze effect of COGIN on distribution fault current. Also, the existing protection system of 22.9[kV] power distribution system and customers protection system to protect of COGIN was analyzed and the study on protective coordination between of two protection system accomplished.