• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.9
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• pp.961-967
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• 2011

The objective of this study was to develop a new method for estimating gas interchangeability for 13A gas appliances. The three basic principles for the development of this method are as follows: 1) to derive the secondary interchangeability factor that represents the effect of gas composition, in addition to the major interchangeability factor, i.e., Wobbe index; 2) to test every type of and each maker's domestic gas appliances that are widely used in our country, particularly including premixed gas appliances; and 3) to develop a simple estimation method. On the basis of these principles, thirty representative gas appliances were tested, and as a result, a simple two-dimensional interchangeability diagram consisting of Wobbe index and relative density was developed. Unlike conventional methods for estimating interchangeability, this method can be applied to premixed gas appliances, which have a narrow stable flame range, and the interchangeability range of this method then becomes narrower than that of the conventional methods.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1995.11a
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• pp.126-138
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• 1995

In order to study the gas interchangeability, a series of tests and analysis were conducted regarding to natural gas and gas mixture. Natural gas was selected as a reference and NG-LPG/Air mixture as a substitute gas. The major interest was placed on the determination of interchangeability limits for different mixing conditions. The parameters of Wobbe Index and Combustion Potential were employed in estimating the gas interchangeability, The limits obtained by analysis(AGA, WEAVER, KNOY, GILB) were compared with experimental results. The results estimated showed that the mixing limits of LPG/Air in proper conditions were found to vary with analysis and AGA is considered to be the most appropriate one.

• Journal of Legislation Research
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• no.41
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• pp.201-228
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• 2011

In 97hu2200, the Supreme Court of Korea suggested five requirements to apply the doctrine of equivalents, i.e. identity of problem-solving principles, interchangeability, ease of interchangeability, exception of known arts and file-wrapper estoppel. There have been arguments on whether the standard of ease of interchangeability could be regarded as the same as the obviousness standard in deciding patentability. The side who thinks that they are different (hereinafter, the side of difference) considers that the standard of ease of interchangeability is narrower than the obviousness standard. This side criticizes the side who thinks that they are the same each other (hereinafter, the side of the same) on the reason that doctrine of equivalents can be overly expanded. On the other hand, 'the side of the same' argues that every accused invention having no inventive step from the perspective of the patented invention should be considered to infringe. 'The side of the same' points that if the standard of ease of interchangeability is considered as narrower than the obviousness standard, 'grey area' should exist where the patent law cannot work. The difference between the two side may cause contradictory results in the decision of infringement under the doctrine of equivalents. Because 'the side of difference' construes claims narrowly than 'the side of the same,' an accused invention in the grey area is not regarded to infringe. 'The side of the same,' however, considers the accused invention to fall into the scope of the patent under the doctrine of equivalents. This paper concludes that the standard of ease of interchangeability should be regarded as the same as the obviousness standard from the perspective of economics of innovation.

• 한국연소학회:학술대회논문집
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• 2012.04a
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• pp.89-91
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• 2012

In this study, an investigation into the gas interchangeability and combustion characteristics of natural gas with various compositions was performed. In order to suggest the appropriateness of gas interchangeability using the specific gravity(SG) and the Wobbe index(WI) values, combustion characteristics, which include incomplete combustion and flame lifting, were measured and observed for the upper and lower limits using the gas-oven as a domestic partial-premixed type appliance and the condensing boiler as a domestic premixed type appliance.

• 한국연소학회:학술대회논문집
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• 2007.05a
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• pp.69-75
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• 2007

In this study, the difference of flame stability zone for natural gases from producing districts was studied experimentally using a new type of flame stability diagram. The similarity of stable flame zone between a domestic appliance and an interchangeability test(IT) burner is also examined. As a result, the stable flame zones expressed by limits curves of flame lifting and yellow tipping show the similar results in a domestic gas range and IT burner. Furthermore, IT burner can reproduce the flash back phenomena and show the distinct difference of fuel type as the burner diameter is increased. To suggest the new type of flame stability diagram in the respect of fuel interchangeability, the air flowrate and Wobbe fuel flowrate were adopted as axis coordinates. It can be identified that the new diagram can provide the useful information on the difference of flame stability zone, heat input rate and air-fuel ratio when a fuel is altered to other fuels under the identical operating conditions. Finally, the stable flame zones for natural gas of 6 type are compared, and the detailed information to use as the interchangeability fuels of standard natural gas is provided using the new type of flame stability diagram.

• Journal of the Korean Society of Combustion
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• v.12 no.1
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• pp.38-47
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• 2007

The diversification of import districts of natural gas is trying to prepare an increase in the demand and price. The interchangeability of natural gases should be examined prior to supply to gas appliances, although compositional differences among natural gases are not large. The object of this study is to investigate numerically the thermodynamic and transport properties as well as information on combustion of 6 natural gases. Comparing the properties of BOG1 with those of standard gas, the maximum differences of heating value, Wobbe index, air-fuel ratio, and specific heat are 10%, 4%, 10% and 5.54%, respectively. That is, the BOG1 is required careful application. However, all gases except for BOG1 show the similar properties with standard gas. Finally, the combustion information such as flame temperature and burning velocity are examined. These results will provide the useful information related to the interchangeability of various natural gases in practical combustion appliances.

• Journal of the Korean Society of Combustion
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• v.13 no.3
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• pp.1-8
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• 2008

A flame stability diagram in a partially premixed flame is typically expressed using the axis coordinates of heat input rate and equivalence ratio. These diagrams are inadequate for identifying changes in combustion conditions and flame stability when a reference fuel is substituted with other fuels under identical operating conditions. This study proposes a new type of diagram and validates it experimentally. In this new diagram, the axis coordinates are air flow rate and Wobbe fuel flow rate, defined as the fuel flow rate multiplied by the square root of the relative density. The diagram was validated in trials using various fuels, including $CH_4$, $C_{3}H_{8}$, and LFG-$C_{3}H_{8}$ mixed fuels, in a domestic gas-range and an gas interchangeability test burner. The results of these trials show that the new diagram can provide information useful for assessing gas interchangeability of combustion conditions and flame stability when one fuel is substituted with another under identical operating conditions.

• Journal of Institute of Control, Robotics and Systems
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• v.2 no.2
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• pp.127-133
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• 1996

This paper represents a new powertrain simulation methodology using the object-oriented programming paradigm. The advantage of the object-oriented is the module interchangeability and simulation flexibility. Powertrain subsystems and controller modules are implemented using the MEX files in MATLAB Simulink in this paper, preserving module interchangeability. Currently, the required CPU time on a 75MHz Pentium PC is about three times the real time. It is anticipated that the "Automotive Powersystem Toolbox" being developed in this research would be of much utility in designing subsystem controllers as well as in designing subsystem mechanicals.chanicals.

• Korea Journal of Hospital Management
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• v.21 no.1
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• pp.43-50
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• 2016

The public medical centers are required to make efficient and profitable operation. The efficiency is usually measured by DEA(data envelopment analysis), and profitability is measured by medical income rate. But DEA is measured by relative, not absolute value. So, profitability rate is used alternatively for DEA. This study want to analyze the interchangeability between DEA ranking and medical income rate ranking among public medical centers. The return on total assets is same ranking with DEA on bed number, employee number and total asset, but 60-70% relationship with DEA on bed number and employee number, as input resources. The operating margin is similar ranking with DEA on bed number and employee number, but 50-60% relationship with DEA on bed number, employee number and total asset, as input resources.

• Korean Institute of Interior Design Journal
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• v.15 no.2 s.55
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• pp.21-28
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• 2006

The purpose of this study was to analyze the characteristics of Kinetic Architecture focused on case studies, categorize them and to research the possible applications of Kinetic Architecture. The results are as follow: first, the background of Kinetic Architecture is from the art, machine, nature and ancient architectures. Second, characteristics of Kinetic Architecture are deployability, modularity, lightweight, simplexity and interchangeability of parts. Third, the types of Kinetic Architecture are dynamically self-erecting structures, kinetic components, incremental architecture, mobile and disposable architecture. Finally, today the application cases of Kinetic Architecture are divided into the spital and skin part. The spital part is a temporary space, the multi-purpose spaces, housing, commercial spaces, and the educational spaces. The skin part offers functional(controling environments), artistic images through variation of materials and structural objects in the elevation.