• New & Renewable Energy
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• v.2 no.3
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• pp.15-22
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• 2006

As the distributed generation becomes more reliable and economically feasible, it is expected that a higher application of the distributed generation units would be interconnected to the existing grids. This new market penetration using the distributed generation technology is linked to a large number of factors like economics and performance, safety and reliability, market regulations, environmental issues, or grid connection standards. KEPCO, a government company in Korea, has performed the project to identify and evaluate the performance of Micro Gas Turbine(MGT) technologies focused on 30, 60kW-class grid-connected optimization and combined Heat & Power performance. This paper describes the results for the mechanical, electrical, and environmental tests of MGT on actual grid-connection under Korean regulations. As one of the achievements, the simulation model of Exhaust-gas Absorption Chiller was developed, so that it will be able to analyze or propose new distributed generation system using MGT. In addition, KEPCO carried out the field testing of the MGT Cogeneration system at the R&D Center Building, KEPCO. The field test was conducted in order to respond to a wide variety of needs for heat recovery and utilization. The suggested method and experience for the evaluation of the distributed generation will be used for the introduction of other distributed generation technologies into the grid in the future.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.2 no.3
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• pp.243-255
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• 1990

The objective of this study is to present an efficient measurement method of the effective thermal diffusivity for the fibrous insulation material. The non-linear parameter estimation (NPE) method is adapted for this analysis because of its accuracy and its results are compared with those by other direct methods such as CTP, CHP and STD method. A experimental system is constructed with bell-jar vaccum chamber, diffusion pump, tube type furnace, control unit and data acquisition system included with A/D converter and IBM XT/AT personal computer. The typical results obtained from this study are as follows; 1) NPE method can be recommended as an useful and accurate method to measure the effective thermal diffusivity of insuation material because it is shown that the measurement error compared with those by other direct methods is reduced for standard material, NBS-1450b. 2) NPE method can minimize the effects of ill-measured temperature due to external disturbance, because the final value is found by point to point estimating. 3) NPE method dose not depend on the kinds of heat flux, since the surfac temperature are used to estimate the thermal diffusivity. 4) With NPE method, compared with the steady state method, a measuring time and a sample size could be reduced.

• Journal of Korean Academy of Nursing
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• v.31 no.2
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• pp.328-339
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• 2001

The purpose of this study was to describe decision making model of 180 public health nurses in Korea and their knowledge structure for decision making. The differences of decision making models by nurse's knowledge structure were also tested. Research concepts were measured using the instrument based on systemic and interpretive decision making approaches that were developed by Lauri & Salantera (1995). The results were as follows. 1. The public health nurses turned to, most commonly, a mixed practical-theoretical knowledge structure (45.9%), followed by practical knowledge (32%) and theoretical knowledge (22.1%). 2. The six different decision making models were identified. These were named for decision making theories and nursing process. These were client-oriented decision making, rule-oriented systemic decision making, wholistic and intuitive decision making, decision making depending on subjective view and experience, systemic decision making for defining problems. 3. The public nurses who had practical and practical-theoretical knowledge structure and community health practitioner (CHP) retold that decision making depends on subjective view and experience. Also the public health nurses who had 5~19 years clinical experience represented hypothetico-deductive decision making for defining problems.

• New & Renewable Energy
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• v.6 no.4
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• pp.15-29
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• 2010

In order to make the best choice for $CO_2$ abatement using renewable energy technologies, it is important to be able to adapt these technologies on the basis of their sustainability, which may include a variety of environmental indicators. This study examined the comparative sustainability of renewable technologies in terms of their life cycle $CO_2$ emissions and embodied energy, using life cycle analysis. The models developed were based on case studies of bioenergy pilot plant in P city of Kyungki province. Final results were total emission of $CO_2$ in Pocheonsi is 670,041 $tCO_2$, around 500,877 $tCO_2$ for electricity and for heat generation, and 169,164 $tCO_2$ for transportation. When used $1,984\;m^3$/day of waste (pig manure etc.) and operated CHP with wood chips of 144,664 ton/year, the $CO_2$ emission in P city was left as is an emission of 449,274 $tCO_2$ and an abatement of $CO_2$ in this region was increased by 32.9%.

• Korean Journal of Pharmacognosy
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• v.25 no.1
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• pp.11-19
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• 1994

Gleditsia japonica var. koraiensis NAKAI(Leguminosae) is commonly distributed in Korea and has been used as a folk medicine in the treatment of bronchitis, neoplasm and blennorrhgia in the Orient. The aqueous acetone extract of the leaves of G. japonica was subjected to a combination of Sephadex LH-20, Cosmosil $75C_{18}-OPN$, TSK-gel Toyopearl HW 40F, Avicel cellulose, and MCI-gel CHP 20P chromatographies with various solvent systems. Twelve compounds were isolated and confirmed to be vitexin(1), isovitexin(2), orientin(3), isoorientin(4), 4-caffeoyl quinic acid(5), 5-caffeoyl quinic acid(6), 3, 5-dicaffeoyl quinic acid(7), 4, 5-dicaffeoyl quinic acid(8), caffeic acid(9), quercetin(10), isoquercitrin(11) and luteolin-7-O-glucoside(12), on the basis of chemical and spectroscopic evidences.

• Journal of Korean Academy of Rural Health Nursing
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• v.13 no.1
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• pp.21-33
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• 2018

Purpose: The purpose of this study was to identify health problems in the community by providing healthy village projects centered and based on the actual living site and to enhance the empowerment of the community related to health. Methods: The participants were 600 people who lived in one of the 5 villages under the jurisdiction of one Primary Health Care Post (PHCP) in D city. The Community Health Practitioner (CHP) carried out the projects to increase geographical and temporal accessibility by building infrastructures through connecting human and physical resources in the community. The health leaders who were trained through the project consistently managed, and periodically checked the residents' health status. Results: The participants in the projects had significantly lower levels of depression, routine stress, and activity of daily living (ADL) disorders, and higher interpersonal relationships, and health-related quality of life (HRQoL) compared to the control group. Conclusions: The healthy village projects centered on the living site led to voluntary participation from the residents, improve HRQoL and enhanced empowerment of community.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.5
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• pp.699-705
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• 2011

A combined heat and power cogeneration system driven by low-temperature sources is investigated by the first and second laws of thermodynamics. The system consists of Organic Rankine Cycle (ORC) and an additional process heater as a series circuit. Seven working fluids of R152a, propane, isobutane, butane, R11, R123, isopentane and n-pentane are considered in this work. Maximum mass flow rate of a working fluid relative to that of the source fluid is considered to extract maximum power from the source. Results indicate that the second-law efficiency can be significantly increased due to the combined heat and power generation. Furthermore, higher source temperature and lower turbine inlet pressure lead to lower second-law efficiency of ORC system but higher that of combined system. Results also show that the optimum working fluid varies with the source temperature.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.3
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• pp.393-398
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• 2015

City or Community-scale Energy Management System(CEMS) is used to reduce the total energy consumed in the city by arranging the energy resources efficiently at the planning stage and controlling them economically at the operating stage. Of the operational functions of the CEMS, generation forecasting of renewable energy resources is an essential feature for the effective supply scheduling. This is because it can develop daily operating schedules of controllable generators in the city (e.g. diesel turbine, micro-gas turbine, ESS, CHP and so on) in order to minimize the inflow of the external power supply system, considering the amount of power generated by the uncontrollable renewable energy resources. This paper is written to introduce numerical models for photo-voltaic power generation prediction based on the weather forecasting information. Unlike the conventional methods using the average radiation or average utilization rate, the proposed models are developed for CEMS applications using the realtime weather forecast information provided by the National Weather Service.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.2
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• pp.121-128
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• 2012

Improvement in the energy efficiency has been studied of the desiccant cooling system by applying a vapor compression type heat pump to modify the system into a hybrid system. The cycle simulation was performed and the results were compared between a reference desiccant cooling system composed of a desiccant rotor, a sensible rotor and a regenerative evaporative cooler, and a hybrid desiccant cooling system with the sensible rotor being replaced by a heat pump. Though the electric consumption increases as much as the compressor power consumption, the total cooling capacity increases and the thermal energy input decreases by the addition of the heat pump. Therefore, the total energy efficiency can be improved if the increase in the electric consumption can be compensated with the increase in the cooling capacity and the decrease in the thermal energy input. The results showed that the total energy efficiency is optimized at a certain heat pump capacity. When the heat from the CHP plant is used for the thermal energy input, the energy consumption of the hybrid system is reduced by 20~30% compared with the reference system when the heat pump shares 30~40% of the total cooling capacity.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.7
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• pp.1339-1346
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• 2011

This paper is developed to demand management scenario of energy consumption efficiency improvement, electricity generation efficiency improvement, network efficiency improvement, change of distribution ratio, movement of energy source, change of heating system, put of CHP to quantitatively assess to impact on energy use of demand management at the national level. This scenario can be applied Energy System Management model was developed based on Energy Balance Flow. In addition, effect analysis through built demand management scenario was quantitatively evaluated integrated demand management effectiveness of energy cost saving, CO2 emission reduction and energy savings of national level by calculating to primary energy source usage change in terms of integration demand management effect more often than not a single energy source separated electricity, heat and gas.