• Proceedings of the Korea Information Processing Society Conference
• /
• 2012.04a
• /
• pp.986-988
• /
• 2012

최적의 식물 생장을 위해서는 적절한 수분의 유지가 필수적이며 넓은 지역, 다양한 종류, 고가의 식물의 경우일수록 적절한 수분의 관리를 위한 시스템의 도움이 필요하다. 이를 위해 저가의 센서노드 시스템이 적절한 해결책이 될 수 있으나 일반적인 배터리 기반의 센서노드 시스템을 적용시 배터리 용량 확인 및 교체 등의 유지보수 문제가 대두된다. 본 논문에서는 이러한 유지보수의 문제를 해결하고 식물재배에 도움을 줄 수 있는 자기유지 지원 방식의 정전용량 센싱기반의 수분 모니터링 센서노드를 설계하였다. UHF 기반의 무선 전력 전송의 자기유지 지원 시스템 및 PCB 패턴기반의 정전용량센싱 수분센서와 초저전력 센서노드 시스템으로 구성된다. 센서노드는 한번 송신시 약 0.24 mJ을 소모하며 에너지획득모듈은 에너지 획득 주기마다 약 4 mJ의 에너지를 공급하도록 설계하여 센서동작을 위한 충분한 에너지 마진을 주도록 설계하였다.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.10 no.11
• /
• pp.1271-1276
• /
• 2015

The recent trend is that diesel power generation on islands where its prime cost for power generation is high is replaced by new and renewable energy. Therefore, south Jeolla province is progressing the construction project of self-sufficient islands for the areas where power is supplied by depending on diesel generators, which is the project that power is supplied through eco-friendly energy source using sunlight, wind power and energy storage device etc. However, it is difficult to construct new and renewable energy source with the capacity to respond to the load perfectly due to its environmental and geographical conditions regarding capacity design of new and renewable energy. Besides, Microgrid design considering appropriate capacity design of the system components and efficient operation is required through the analysis of climate conditions and load patterns from the design stage for optimal composition of a hybrid system with economic feasibility. Therefore, this study is aimed to conduct a research on optimal combination, capacity calculation and economic feasibility by comprising a hybrid power generation system which will replace 40% of power generation by diesel as new and renewable energy source for Geomun Island where has more than 300 households and requires expansion of the facility among islands located in southwest coast.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.34 no.3
• /
• pp.283-289
• /
• 2010

Owing to the increasing worldwide interest in green technology and renewable energy sources, flywheel energy storage systems (FESSs) are gaining importance as a viable alternative to traditional battery systems. Since the energy storage capacity of an FESS is proportional to the principal mass-moment of inertia and the square of the running speed, a design that maximizes the principal inertia while operatingrunning at the highest possible speed is important. However, the requirements for the stability of the system may impose a constraint on the optimal design. In this paper, an optimal design of an FESS that not only maximizes the energy capacity but also satisfies the requirements for system stability and reduces the sensitivity to external disturbances is proposed. Cross feedback control in combination with a conventional proportional-derivative (PD) controller is essential to reduce the effect of gyroscopic coupling and to increase the stored energy and the specific energy density.

• Journal of Energy Engineering
• /
• v.2 no.1
• /
• pp.95-103
• /
• 1993

A conceptual thermoelectric heat pump(cooling mode) of small capacity is designed. Its performance is investigated through parametric analysis. COP and cooling capacity decease as the ambient temperature increases with ${\mu}$, J, T$\sub$wi/, fixed. To design a system of fixed capacity comes to calculate ${\mu}$ and J when T$\sub$wi/, and T$\sub$a/ are given. As v is fixed by semi-conductor manufacturers, optimum combination of n and I should be searched for ν. Optimum current could be calculated using ${\mu}$-J curve and optimum value of ${\mu}$. COR$\sub$R/ increases as water flow rate increases and T$\sub$a/ decreases. The effect of heat transfer coefficient at hot(heat releasing) side is more significant than that at cold(heat absorbing) side.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
• /
• v.40 no.4
• /
• pp.11-17
• /
• 2011

적정한 환기용량의 산정과 최적의 환기방식선정으로 공사비를 절감하고, 운영 중의 안전성도 확보하는 방안을 소개하고자 한다.

• Journal of the Korea Convergence Society
• /
• v.8 no.6
• /
• pp.219-226
• /
• 2017

As the UAV industry is getting matured, various types of UAVs have appeared in many application fields, including filming, reconnaissance, rescue, and etc. and it requires the quick hardware designs, particularly a battery pack, of the UAV. We developed the automatic battery pack design tool for the convenient battery pack configuration design of the hoverable type delivery UAV. With inputs, including current profile, voltage profile, various kinds of cell specifications, desired battery pack voltage, and etc. the automatic battery pack design tool calculates a pack having the minimum weight and the maximum capacity by combining either homogeneous cells or heterogeneous cells. Also, the tool could predict the capacity fading trend of the designed battery pack configuration.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.6 no.5
• /
• pp.37-43
• /
• 2002

In this paper, an integrated optimum design method for hybrid structural control system is studied. Not only the distribution and the capacity of passive devices but also those of active devices, and the controllers are treated as design variables in the proposed approach. Multi-objective optimization problem is formulated by using the preference function, which is newly defined in this study. Genetic algorithm is adopted as a numerical searching technique in order to simultaneously find the optimum solutions. The validity of the proposed method is verified through the example designs and the numerical simulations of an earthquake excited multi-degrees-of-freedom structure.

• Membrane Journal
• /
• v.30 no.1
• /
• pp.21-29
• /
• 2020

In this study, we have established the optimum design condition of pore-filled anion-exchange membrane for all-vanadium redox flow battery (VRFB). From the experimental results, it was proven that the membrane design factors that have the greatest influence on the charge-discharge performance of VRFB are the ion exchange capacity, the porosity of substrate film, and the crosslinking degree. That is, the ohmic loss and the crossover of active materials in VRFB were shown to be determined by the above factors. In addition, two methods, i.e. reducing the ion exchange capacity at low crosslinking degree and increasing the crosslinking degree at high ion exchange capacity, were investigated in the preparation of pore-filled anion-exchange membranes. As a result, it was found that optimizing the crosslinking degree at sufficiently high ion exchange capacity is more desirable to achieving high VRFB charge-discharge performances.

• Environmental and Resource Economics Review
• /
• v.25 no.1
• /
• pp.113-140
• /
• 2016

Achieving the two goals of providing stable remuneration and promoting market based incentive for generation capacity with only one kind of capacity price is a difficult proposition. This paper suggests a market design in which two different kinds of capacity prices are used to achieve these goals. It maintains the current capacity price that is determined administratively based on the fixed cost of the gas-turbine generator. A second capacity price is added that covers generators with higher fixed costs and lower fuel costs such as combined-cycle gas turbine, coal-powered, and nuclear generators. This second capacity price is conditional on a lower energy price ceiling and determined by the interaction of the market supply and a demand schedule derived from the optimal fuel mixed principle.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.5 no.3
• /
• pp.9-24
• /
• 1968

This report is concerned with the optimum design of hyper-aprupt p-n junctiea silion diode and fabriction of this diode usable for electrical tuning application. Impurity profile in the junction was assumed to clean exponential function. With this assunntion, an optimum criterion for designing standard AM radio tuning capacitor was derived. In the diffusion process, after aluminum and antimony as impurties were deposited in vacuum on a P-type silicon wafer, the diffusion was followed by loading the wafer into the high temperature furnace.