• Journal of Biomedical Engineering Research
• /
• v.9 no.1
• /
• pp.109-116
• /
• 1988

In this paper, principles of impedance tenchinque and relationship between stroke volume and impedance change were theoretically explained. An impedance cardiograph was designed and constructed. Its reproducibility was verified by experiment. Until now, the peak point of dZ/dt waveform, first derivative of impedance change(${\Delta}$Z) , has been detected by software technique requiring considerable time to process. However in this paper its peak point was found using hardware for saving processing time. Useful cardiac parameters such as stroke volume and contractility of cardiac muscle were measured noninvasively. The reproducibility of the instrument was measured to be better(less than 10%) than that of clinical standard method such as thermodilution (more than 30%). Hence impedance cardiography was found to be better techique for monitoring stroke volume and myocardial contractility for pre and post operation, and pharmacological studies.

• Journal of Korean Society for Quality Management
• /
• v.34 no.4
• /
• pp.133-138
• /
• 2006

In this paper, we propose a software reliability growth model (SRGM) based on the testing domain, which is isolated by the executed test cases. This model assumes an imperfect debugging environment in which new faults are introduced in the fault-correction process. We consider that the fault detection rate of NHPP model is changed in the proposed SRGM. We obtain the maximum likelihood estimate, and compare goodness-of-fit with another existing software reliability growth model.

• KIEAE Journal
• /
• v.12 no.1
• /
• pp.65-71
• /
• 2012

This study aims to find out a institutional base in urban planning and urban project, confronted with climate change and necessity of sustainable development in France. The establishment of Grenelle Environment Law became a start point to draw concrete effect and implement urban projects. The relation in urban policy on climate change and its concrete shape in urban projects are examined in this paper, especially focused on HQE2R criteria and Eco-Quartier projects. It provides various information on ways to improve Korea urban planning, urban revitalization and development projects, which is in similar situations and necessity in France. As shown in the case of France, for the sustainable urban development related on climate change, it is necessary of Central Government's firm and clear policy framework, as well as the institutions and organizations linked to actual process of local communities are required. In addition, through the development of indicators applicable to urban development and architectural process, objective and rational framework for planning and design standards should be established.

• Journal of Institute of Convergence Technology
• /
• v.3 no.1
• /
• pp.9-14
• /
• 2013

Recently, the development of renewable energy sources in Mongolia has been needed due to climate change and air pollution in Ulaanbaatar as rapid economic growth. Biodiesel can be considered as an alternative fuel for petroleum based diesel in order to decrease air pollution in Ulaanbaatar because of its no emission of particle materials from internal combustion engine in automobile. Rapeseed oil having low cloud point and pour point was suggested as a promising raw material for biodiesel production in Mongolia. Considering high population density and severe air pollution by particle materials and SOx in Ulaanbaatar, prior supplying site of biodiesel in Mongolia was the capital region including Ulaanbaatar. In the production of biodiesel in Mongolia, adsorption process was a effective alternative to washing process for the removal of residual alkali catalyst and reactants due to long winter time in Mongolia. For the stable supply of biodiesel, subsidy and no tax policy is needed in the early stage of biodiesel supply in Mongolia.

• Journal of the Society of Naval Architects of Korea
• /
• v.55 no.5
• /
• pp.415-420
• /
• 2018

The development of sail gas has increased the production of ethane as well as natural gas. The decline in the market price for ethane has led to a change in the petroleum-based ethylene production process into an ethane-based ethylene production process and an increase in the ethane/ethylene trade volume. Large-scale ethane/ethylene carrier have been needed due to an increase in long-distance trade from the US, and cargo type change have leaded to consider a liquefaction process to re-liquefy Boil-Off gas generated during the voyage. In this paper, the liquefaction system of Liquefied Ethane Gas carrier was evaluated with Low-GWP (Low-Global Warming Potential) refrigerant and process parameters, Boil-Off Gas pressure and expansion valve outlet pressure, were optimized. Low-GWP refrigerants were propane (R290), propylene(R1270), carbon dioxide(R744) was considered at two type of liquefaction process such as Linde and cascade cycle. The results show that the optimal pressure point depends on the individual refrigerant and the highest liquefaction efficiency of carbon dioxide (R744) - propane (R290) refrigerant.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.4
• /
• pp.1193-1215
• /
• 2021

The measurement of the key product quality index plays an important role in improving the production efficiency and ensuring the safety of the enterprise. Since the actual working conditions and parameters will inevitably change to some extent with time, such as drift of working point, wear of equipment and temperature change, etc., these will lead to the degradation of the quality variable prediction model. To deal with this problem, the selective integrated moving windows based principal component regression (SIMV-PCR) is proposed in this study. In the algorithm of traditional moving window, only the latest local process information is used, and the global process information will not be enough. In order to make full use of the process information contained in the past windows, a set of local models with differences are selected through hypothesis testing theory. The significance levels of both T - test and χ² - test are used to judge whether there is identity between two local models. Then the models are integrated by Bayesian quality estimation to improve the accuracy of quality variable prediction. The effectiveness of the proposed adaptive soft measurement method is verified by a numerical example and a practical industrial process.

• Journal of the Korean Society of Earth Science Education
• /
• v.8 no.1
• /
• pp.56-65
• /
• 2015

The purpose of this study is to investigate how elementary school student understands or students understand the illustrations on the phase change of the Moon in science textbook and to find out how textbook illustration helps students form the conception of the phase change of the Moon. To identify this purpose, we selected illustrations on the phase change of the Moon in the science textbook revised in 2007 and 2009 revised science textbook. For this study we selected and interviewed 20 students in the fifth grade. We integrated all data collected through interviews and created a transcription and a protocol and then, confirmed scientific conceptions related to the phase change of the Moon in students' illustration reading. The result are as followings: First, students read more scientific conceptions related to the phase change of the Moon in illustration of the 2009 revised science textbook which is presented with the universal observer's view point and the earth observer's view point. Second, students who find meaning in the various elements of the illustration and interpret with the integration of the various elements, get a lot of relevant information from illustration. All students have no differences recognizing the elements presented in illustration. But there are differences of contents of illustration reading depending on how students interpret the illustrations with integration of the various elements and if students cannot figure out the four scientific concepts needed to understand the phase change of the Moon, they ignore the information provided by illustration or analysis in their own way according to information provided by illustration. So misconception appears in this process.

• Proceeding of Spring/Autumn Annual Conference of KHA
• /
• 2005.11a
• /
• pp.205-209
• /
• 2005

A traditional settlement, in a long history establishment, is appeared to be configured of the people and their life in the areas. This is, a positive aspects, compared to most of the city in these day which is monotonous aspects. The purpose of this research deals what is the formation process and spatial character in urban settlement of Naju city, and how to applicate in a modern city context. For the research goals, it analyse an old Naju Castle area, transformation of the land use through the cadastral survey, and spatial character through step by step in chronical approach. The process of change can be seen in the devide pattern in a lot, formation and extension of a private road, and formation and change of the road; This shows how to changes traditional settlement in a old urban areas of Naju city. A now road system in old area, as a conflict, push the change of the spatial organization, and the balance of the identity of a traditional settlement and a new change as a convenient needs, it is a key point to get ideal settlement.

• Journal of Powder Materials
• /
• v.27 no.2
• /
• pp.139-145
• /
• 2020

The powder manufacturing process using the gas atomizer process is easy for mass production, has a fine powder particle size, and has excellent mechanical properties compared to the existing casting process, so it can be applied to various industries such as automobiles, electronic devices, aviation, and 3D printers. In this study, a modified A4032-xSn (x = 0, 1, 3, 5, and 10 wt.%) alloy with low melting point properties is investigated. After maintaining an argon (Ar) gas atmosphere, the main crucible is tilted; containing molten metal at 1,000℃ by melting the master alloy at a high frequency, and Ar gas is sprayed at 10 bar gas pressure after the molten metal inflow to the tundish crucible, which is maintained at 800℃. The manufactured powder is measured using a particle size analyzer, and FESEM is used to observe the shape and surface of the alloy powder. DSC is performed to investigate the change in shape, according to the melting point and temperature change. The microstructure of added tin (Sn) was observed by heat treatment at 575℃ for 10 min. As the content of Sn increased, the volume fraction increased to 1.1, 3.1, 6.4, and 10.9%.

• The KIPS Transactions:PartD
• /
• v.10D no.1
• /
• pp.45-56
• /
• 2003

In the wireless environment, according to the development of technology, which is able to obtain location information of spatiotemporal moving object, the various application systems are developed such as vehicle tracking system, forest fire management system and digital battle field system. These application systems need the data model, which is able to represent and process the continuous change of moving object. However, if moving objects are expressed by a relational model, there is a problem which is not able to store all location information that changed per every time. Also, existing data models of moving object have a week point, which constrain the query time to the time that is managed in the database such as past or current and near future. Therefore, in this paper, we propose a data model, which is able to not only express the continuous movement of moving point and moving region but also process the operation at all query time by using shape-change process and location determination functions for past and future. In addition, we apply the proposed model to forest fire management system and evaluate the validity through the implementation result.