Abstract:
The present invention relates to a positive electrode active material for a lithium secondary battery and manufacturing method of same in which the positive electrode active material is lithium-nickel-manganese based oxide LiNixMn2-xO4 (0
Abstract:
PURPOSE: LiFePO4 positive electrode active material for a lithium ion battery is provided to improve tap density(apparent density) and to reduce use amount of a binder when manufacturing a positive electrode for a lithium secondary battery. CONSTITUTION: An LiFePO4 positive electrode active material includes a spherical particle. A plurality of pores with a particle diameter of 2-300 nm are distributed on the surface of the particle or bulk, thereby having porosity. According to charging or discharging operation, the insertion or deintercalation of cations can be possible both on the surface of the particle and bulk. The spherical particle has a porosity of 1-50%, and the specific surface area thereof is 0.1-100 m^2/g.
Abstract:
본 발명은, 구형 구조의 입자를 가지며, 상기 입자의 표면 및 벌크에 2∼300㎚의 직경을 갖는 복수의 기공들이 분포되어 다공성을 나타내고, 상기 입자의 평균 입경이 1∼5㎛이며, 충전 또는 방전 동작에 따라 상기 복수의 기공들을 통해 상기 입자의 표면 및 벌크 모두에서 양이온의 삽입 또는 탈리가 가능한 리튬이온전지용 LiFePO 4 양극 활물질의 제조방법에 관한 것이다. 본 발명에 의하면, 입자의 표면 및 벌크에 2∼300㎚의 직경을 갖는 복수의 기공들이 분포되어 다공성을 나타내므로 충전 또는 방전 동작에 따라 상기 복수의 기공들을 통해 상기 입자의 표면 및 벌크 모두에서 양이온의 삽입 또는 탈리가 가능하고, 마이크로 크기를 갖는 균일한 구형 입자를 가짐으로써 종래의 LiFePO 4 양극 활물질보다 탭 밀도(겉보기밀도)가 향상되고 리튬이온전지용 양극 제조시에 바인더의 절대 사용량을 감소시킬 수 있다.
Abstract:
PURPOSE: A positive active material for a lithium secondary battery is provided to improve the lifetime of a lithium secondary battery by suppressing the elution of manganese at high temperatures. CONSTITUTION: A positive active material includes a lithium-boron-based oxide glass coated on the surface of lithium-nickel-manganese oxide. The lithium-nickel-manganese oxide is LiNi_xMn_(2-x)O_4 in a spinel crystal structure, in which 0
Abstract:
본 발명은 SDR(Software Defined Radio) 기술과 CR(Cognitive Radio) 기술을 도입한 기지국 시스템의 재구성 최적 방법과 그 플랫폼에 관한 것이며, 이를 위해 기지국 주변 무선 채널 환경을 측정 및 인지, 최적의 주파수 자원할당, 주변 채널환경에 최적화된 송수신 알고리즘 판단 및 수립, 송수신기 시스템의 재구성 순서로 동작한다. 이와 같이, 본 발명은 요소기능들이 공통된 목적에 의해 유기적으로 결합 및 연동하여 최적의 서비스를 제공한다. 시스템 재구성, 다중모드 기지국, SDR 시스템, CR 기술
Abstract:
A method for optimizing radio resource assignment by using a genetic algorithm to which a goal programming scheme is applied, and a computer readable medium recording a program which uses the same are provided to obtain an optimal solution easily, to enhance a solution convergence speed, to reduce unnecessary power consumption by lowering system complexity, and to optimize resources and system variables. A method for optimizing radio resource assignment comprises the following several steps. Degree of satisfaction to the goal is determined, and the first front is assigned to entities which satisfy the first degree of satisfaction to the goal which is set up according to the request of resources or a system(SG1). Dummy fitness is assigned to entities to which the first front is assigned(SG2). Fitness is shared like a conventional NSGA(Non-dominated Sorting Genetic Algorithm), and the front is increased(SG3,SG4). If the steps are repeated, other degree of satisfaction to the goal for each front can be set up. If the fronts are assigned to all the entity group(S1), reproduction(S2), cross(S3) and mutation(S4) are passed, and then a generation number is increased, and the steps S1-S4 are repeated until the generation number arrives at a maximum generation number.
Abstract:
본 발명은 유전자 알고리즘을 이용한 자원 및 시스템 변수의 최적화 방법에 있어서, 설정된 목표에 따라 자원 및 시스템 변수의 가능한 해를 구하는 단계, 구한 해를 제1 순위(1st front)로 설정하는 단계, 제1 순위에 적합도 값을 할당하는 단계를 포함하며, 이를 실현한 프로그램을 기록한 컴퓨터로 읽을 수 있는 기록매체, 및 이러한 방법을 이용한 무선 자원 할당의 최적화 방법을 제시함으로써, 해의 수렴속도를 빠르게 하고 최적의 해를 손쉽게 구할 뿐만 아니라, 시스템 복잡도를 현저히 낮춤으로써 불필요한 전력소모를 감소시키고, 시스템의 유연성을 부가함으로써, 자원 및 시스템 변수의 최적화를 용이하게 이룩하도록 하는 효과가 있다. 다목적 최적화 알고리즘, 무선 자원 할당, 인지무선통신
Abstract:
A platform and a method for reconfiguring a reconfigurable base station are provided to offer a user high quality service as well as to enhance efficiency of frequency resources by changing frequencies or services selectively according to an environment, a user request or QoS(Quality of Service). A platform for reconfiguring a reconfigurable base station includes a CR(Cognitive Radio) function unit(100) and an SDR(Software Defined Radio) platform(200). The CR function unit actively recognizes a situation like a channel feature caused by different frequencies, time assignment distribution or unique environment characteristics and assigns available wireless resources to a user based on the recognized information. The SDR platform reconfigures flexibly a transmitting or receiving system like a base station or a terminal via a software based on transmitting or receiving algorithm information like information on frequencies, bandwidth, a multiplexing scheme, a modulating/demodulating scheme, channel coding, transmission power and others.
Abstract:
A method for optimizing cognitive radio communication system variables and a computer-readable recording medium storing a program therefor are provided to increase a convergence speed by allocating an arbitrary solution within a target range as a system variable of radio communication and reducing radio configuration genes of a chromosome used for a gene algorithm. System variables required to be optimized by the user of radio communication are set as knobs or meters(S1). A target that can be set in the system with respect to the set knobs or meters is set(S2). A solution within the bounds of the target is extracted among solutions of the system variables(S3). System variables are set according to the solution(S4).