• 대한가정학회지
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• 제20권4호
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• pp.155-168
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• 1982

What is attempted here is to find out an optimum method for the design of physical environments that could save human energy expenditures and safely perform household duties. There are, if any, very little amount of research done in this area. This is particulary so when the work relates to the designing of household storage facilities in the light of the energy metabolism of human body. The first step to this study, therefore, is to find out the ways by which we can determine the energy metabolism of human body accurately. To measure the volume and the concentration of human respiration continuously and automatically, a new apparatus is selected here. This includes the recording system with the Wright Respirometer and the Expired Gas Analyzer as well as the computer system to multiply volume by concentration of human respiration and to integrate them for a given time. Then, the author experimented on the reliability of this apparatus and came to the conclusion that this apparatus satisfied our need to research the energy metabolism of human body. Next, the general plan and procedures to experiment with this apparatus have been determined as follows: 1) subjects are three young and sound females. Their physical characteristics are shown in Table 1 and most approximates the standard characteristics of Japanese females, 2) height of open shelves is selected in such away as to correspond to the respective height of each subject(see Table 2), 3) utensils to be stored are box shaped object, which weight is 0.5kg, 1.0kg, 2.0kg or 3.0kg, 4) working motions are given while one or two hands as to place utensil on each shelf from the standard working board, 85 cm in height and then to place back it on the board from the shelf and repeated in constant velocity as 10 times per a minute, 5) each posture of motion is chosen by each subject in free, 6) procedures of measurement of human energy metabolism ard shown at(6), 1, Section 3 as specific methods for using this apparatus. Findings of this study are as follows: 1. Human energy expenditures for storing utensils on shelves by each subject are shown in quantity more accurately than in any other studies, under varying conditions about height of shelves, load of utensils and working motion with one hand and two hands (see Fig. 8~13 and Table 3). 2. Experimental formulae of human energy expenditure for that work are shown as formula (8), (9) and (10), to generalize results of 1. and to apply those for working motion under given conditions. 3. As results of analysis on gained data, we are able to show the standard model of human energy expenditures for storing untensils on shelves by the standard Japanese female (see Table 7 and Fig. 14).

• 태양에너지
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• 제7권1호
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• pp.3-13
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• 1987

A batch type passive solar water systems, which perform the dual function of absorbing the solar energy and storing the heated water, have been designed and fabricated for the purpose of side-by-side testing at KIER. The test models included an A, B and C type batch systems which were classified according to the design of box and arrangement of tanks. The year-round performance tests show that B type batch system taken the step-wise tank arrangement indicates 55.7% yearly-average collection efficiency factor and 61% yearly-average maximum collection efficiency factor. Computer-aided-experimental results show that the sufficient hot water can be obtained in the early morning if the glazing is supplemented by a reflector/insulation cover. The thermal performance equation has been developed for the prediction of hourly variation of the water temperature in tank.

• Bulletin of the Korean Chemical Society
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• 제34권7호
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• pp.2029-2035
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• 2013

The impact of phosphorous (P)-doping on the electrochemical performance and surface chemistry of soft carbon is investigated by means of galvanostatic cycling and ex situ X-ray photoelectron spectroscopy (XPS). P-doping plays an important role in storing more Li ions and discernibly improves reversible capacity. However, the discharge capacity retention of P-doped soft carbon electrodes deteriorated at $60^{\circ}C$ compared to non-doped soft carbon. This poor capacity retention could be improved by vinylene carbonate (VC) participating in forming a protective interfacial chemistry on soft carbon. In addition, the effect of P-doping on exothermic thermal reactions of lithiated soft carbon with electrolyte solution is discussed on the basis of differential scanning calorimetry (DSC) results.

• 한국태양에너지학회 논문집
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• 제37권2호
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• pp.67-75
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• 2017

We have investigated the operating characteristics of $1,600m^2$ large-scale solar thermal system installed in an eco-friendly energy town in Chungbuk Innovation City. The operation criteria of the collecting pump and storage pump were different from the existing standard, and it was confirmed that each pump works well according to the changed criteria. Based on the data of the representative day, the daily collecting heat (efficiency) and the production (storing) heat (efficiency) were estimated. It was confirmed that the daily collecting heat (efficiency) of the flat plate type was higher than that of the evacuated tube type, but the useful heat production was more in evacuated tube type collector.

• Progress in Superconductivity
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• 제13권1호
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• pp.52-57
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• 2011

A superconductor flywheel energy storage system (SFES) is an electro-mechanical battery which transforms electrical energy into mechanical energy for storage, and vice versa. The 35 kWh class SFES is composed of a main frame, superconductor bearings, electro-magnetic dampers, a motor/generator, and a composite flywheel. The energy storing capacity of the SFES can be limited by the operational speed range of the system. The operational speed range is limited by many factors, especially the resonant frequency of the main frame and flywheel. In this study, a steel frame has been designed and constructed for a 35 kWh class SFES. All the main parts, their housings, and the flywheel are aligned and assembled on to the main frame. While in operation, the flywheel excites the main frame, as well as all the parts assembled to it, causing the system to vibrate at the rotating speed. If the main frame is excited at its resonant frequency, the system will resonate, which may lead to unstable levitation at the superconductor bearings and electro-magnetic dampers. The main frame for the 35 kWh class SFES has been designed and constructed to improve stiffness for the stable operation of the system within the operational speed range.

• 전기학회논문지
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• 제62권1호
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• pp.63-69
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• 2013

In recent years, technology for storing a preliminary power or a surplus of photovoltaic energy is required. This technique, as well as store a preliminary energy and improve the reliability of the gird safety. This system can plan a efficient power generation through the flexibility of the power supply from the perspective of not only provider but also user. Accordingly, the realization of the smart grid can be expected. This paper proposes a hybrid PCS using a photovoltaic and a lithium-polymer battery with the characteristics of high density energy. The main energy source of a hybrid PCS is a photovoltaic, grid and the auxiliary energy source is a lithium-polymer battery. The operation of a proposed system in this paper is verified with simulation and experimental results.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 춘계학술대회
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• pp.253-256
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• 1997

KESF-1 foot conceptually provides storage of potential energy and is converted to kinetic energy throughout the weight - bearing phase of the gait cycle. This stored energy is progressively released as the foot continues through the toe-off phase to rebound and propel the body forward. A weight deflects the keel through a predetermined range, then the keel "springs back" as weight is removed. Foot designs criteria were selected to guide development beyond the proof-of concept composite material keels; 1) store and return energy (1-3/4 " metatarsal deflection at 435 pounds vertical load), 2) natural feel and stability; 3) useful life of 3-years: 4) lightweight; 5) reduced production costs. The purpose of this study is developed the comfortable stable foot that fitted with Korean lifestyle and road condition. The results produced the realistic cosmetic foot cover with polyurethane form and the keel composed with composite materials of both glass fiber and carbon fiber.

• 한국통신학회논문지
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• 제34권12B호
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• pp.1435-1443
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• 2009

본 논문에서는 에너지 수확 센서 네트워크 시스템을 DEVS 형식론을 이용해서 시뮬레이션하고 모델링한다. 이 시스템은 주전원이나 배터리를 사용하는 싱크(마스터(master)) 노드와 에너지 수확 소자로부터 전원을 공급 받는 센서(slave) 노드로 구성 된다. 시뮬레이션을 위해 (i) 슬레이브 노드에서 에너지 수확하고 저장하는 회로의 동작을 연속적인 구간들로 분할한 후에 각 구간을 이산적인 상태로 표현하고, (ii) 마스터 노드와 슬레이브 노드의 컴포넌트들의 동작의 관계를 면밀하게 분석하여, (iii) 분석된 결과를 DEVS 형식론을 이용하여 모델링하고 시뮬레이션 한다.

• 한국인터넷방송통신학회논문지
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• 제20권2호
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• pp.179-185
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• 2020

DRAM은 메인 메모리 시스템을 구성하는 주요한 요소로서 운영체제의 발전, 응용 프로그램의 복잡도와 용량의 증가에 맞추어 DRAM의 용량과 속도 역시 증가하는 추세이다. DRAM은 주기적으로 저장된 값을 읽은 후 다시 저장하는 리프레시 동작을 수행해야 하며, 이에 수반되는 성능 및 파워/에너지 오버헤드는 용량이 증가할수록 더 악화되는 특성을 내재하고 있다. 본 연구는 전하의 보존 시간이 가장 낮은 셀들에 대해서 블룸 필터를 사용하여 64ms, 128ms 이내에 리프레시를 수행해야 하는 로우들을 효율적으로 저장하여 선택적 리프레시를 수행하는 에너지 효율 향상 기법을 제안한다. 실험 결과에 따르면 제안 기법을 통하여 평균 5.5%의 성능 향상이 있었으며, 리프레시 에너지는 평균 76.4% 절감되었고, 평균 EDP는 10.3% 절감된 것으로 나타났다.

• 한국수소및신에너지학회논문집
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• 제31권2호
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• pp.184-193
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• 2020

One of the technical methods to increase the volumetric energy density of hydrogen is to pressurize the gaseous hydrogen and then contain it in a rigid vessel. Especially for automotive systems, the compressed hydrogen storage can be found in cars as well as at refueling stations. During the charging the pressurized hydrogen into a vessel, the temperature increases with the amount of stored hydrogen in the vessel. The temperature of the vessel should be controlled to be less than a limitation for ensure stability of material. Therefore, the accurate estimation of temperature is of significance for safely storing the hydrogen. In this work, three well-known cubic equations of state (EOSs) were adopted to examine the accuracy in regenerating thermodynamic properties of hydrogen within the temperature and pressure ranges for the compressed hydrogen storage. The formulations representing molar volume, internal energy, enthalpy, and entropy were derived for Redlich-Kwong (RK), Soave-Redlioch-Kwong (SRK), and Peng-Robinson (PR) EOSs. The calculated results using the EOSs were compared with literature data given by NIST. It was revealed that the accuracies of RK and SRK EOSs were satisfactorily compatible and better than the results by PR EOS.