• Plant Journal
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• v.13 no.2
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• pp.39-45
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• 2017

This paper is a study on FEED validation model that can be used in the bidding stage of small utility equipment in offshore plant industry using system engineering technique. Currently, domestic marine plant equipment industry companies are faced with the financial risk of project execution as they enter marine plant. The major cause was the insufficient ability to verify the FEED output from the contractor (Engineering or Procurement and Construction) of the equipment manufacturer (COMPANY or EPC). Therefore, we propose FEED design verification method that simplifies the system engineering method that sequentially applies requirements analysis, function, performance analysis and physical architecture building process. Also, we verified the suitability of the developed model by comparing the results of applying the developed FEED verification model and the verification method that depends on the existing experience for the small utility equipment (Air Compressor).

• Journal of the Korea Convergence Society
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• v.10 no.11
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• pp.321-326
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• 2019

As the use of public transportation increases, many researches are being carried out to increase the fuel economy of car. The goal of this study is to design a front body in order to increase the fuel economy of car through three models of cars. All models were designed with CATIA program and the flow analyses on the air outside car by model were carried out with ANSYS program. At the driving speed of 90km/h, the longer the body, the less air resistance it received. So, it is thought that there is the effect to increase fuel economy. Through this study, it can be helpful to design the front car body that can maximize train efficiency. By utilizing the design data on flow analysis according to the position of radiator inside car in this study, the esthetic sense can be given by being grafted onto the real automotive part.

• Journal of the Korea Convergence Society
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• v.10 no.8
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• pp.159-164
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• 2019

The front bumper of bobsleigh is mounted to alleviate the impact, but the air resistance to the bobsleigh depends on the body shape positioned in front. This study was conducted the flow analyses about three kinds of bobsleigh configurations. Models B and C with the sharp type of the front can reduce the air resistance than model A with the round type of the front. And the type that the back of the bumper narrows can generate a flow smoother than the one widening. It is thought that the results of this study can be devoted at ensuring the body design to reduce the flow resistance most at bobsleigh. As the design data with the durability of bobsleigh obtained on the basis of this study result are utilized, the esthetic sense can be shown by being grafted onto the machine or structure at real life.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.3
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• pp.289-296
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• 2021

The Korean construction industry has been implementing G-SEED, a certification system that evaluates the environmental properties of buildings for the purpose of reducing environmental burdens such as energy and resource consumption and pollutant emissions. Also, creating a pleasant environment in general is one more purpose of G-SEED certification system. However, G-SEED certification in practice is difficult and time consuming due to the complexity of the certification acquisition process coupled with little economic consideration for the materials of each certification item. Therefore, in this study, we present a model for the optimal selection of materials and economic assessment using a genetic algorithm. The development of the model involves building a material database based on life-cycle costing (LCC) targeted at "Application of Indoor Air Pollutant Low Emission Material" from G-SEED. Next, the model was validated using a real non-residential building case study. The result shows an average cost reduction rate of 74.5 % compared with the existing cost. This model is expected to be used as an economically efficient tool in G-SEED.

• Journal of Aerospace System Engineering
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• v.17 no.6
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• pp.100-107
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• 2023

Open-phase fault in a Permanent Magnet Synchronous Motor (PMSM) occurs due to disconnection of phases of motor windings or inverter switch failures. When an open-phase occurs, it leads to the generation of torque ripples and vibrations in the motor, which can have a critical impact on the safety of the vehicle (including aircraft) using a PMSM as an actuator. Therefore, rapid fault detection and classification are essential. This paper proposes a classification method for detecting open-phase faults and locating fault positions in a PMSM used in aircraft applications. The proposed approach uses an Extended Kalman Filter for fault diagnosis, and it subsequently classifies faults using a Multiple Model filter.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.10
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• pp.911-918
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• 2013

The combustion characteristics of an EV (Environmental Vortex) burner (double-cone burner) adopted in a gas turbines are numerically investigated. The mixing of fuel and air is analyzed for reduction of NO emission. To predict the correlation between NO emission and fuel-air mixedness, 1-step and 2-step chemistry models are adopted. The results calculated by 1-step chemistry showed that NO emissions increased by 2% in the case of degraded mixedness and by 169% in the case of improved mixedness, where the temperature in the flame zone was overestimated upstream of the cone. However, the corresponding results calculated by 2-step chemistry showed that NO emission increased by 3% and decreased by 5%, where the flame zone was not formed inside the cone. The latter results agree well with the experimental ones indicating an increase of 63% and decrease of 11% in the respective cases. Despite quantitative errors, NO emissions can be predicted reasonably by the application of the 2-step chemistry model adopted here and design modification of burner for NO reduction can be proposed based on the numerical data.

• The Journal of the Acoustical Society of Korea
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• v.19 no.6
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• pp.62-70
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• 2000

In usual language models(LMs), the probability has been estimated by selecting highly frequent words from a large text side database. However, in case of adopting LMs in a specific task, it is unnecessary to using the general method; constructing it from a large size tent, considering the various kinds of cost. In this paper, we propose a construction method of LMs using a small size text database in order to be used in specific tasks. The proposed method is efficient in increasing the low frequent words by applying same sentences iteratively, for it will robust the occurrence probability of words as well. We carried out continuous speech recognition(CSR) experiments on 200 sentences uttered by 3 speakers using LMs by iterative teaming(IL) in a air flight reservation task. The results indicated that the performance of CSR, using an IL applied LMs, shows an 20.4% increased recognition accuracy compared to those without it. This system, using the IL method, also shows an average of 13.4% higher recognition accuracy than the previous one, which uses context-free grammar(CFG), implying the effectiveness of it.

• The KIPS Transactions:PartD
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• v.13D no.6 s.109
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• pp.789-796
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• 2006

Context-aware is the core in ubiquitous environment of sensor network to support intelligent and contextual adaptation service. The new context information model is demanded to support context-aware applications. The model should not depend on a specified application and be shareable between applications in the same environment. Also, it should support various context representation and complex context-aware. In this paper, we define the context information according to context-aware process. Also we design the knowledge of domain as well as applications using ontologies and rules. The domain spatial ontology and application knowledge are represented using the spatial object model and the rules of expanded ontologies, respectively. The expression of abundant spatial ontology represents the context information about distance between objects and adjacent object as well as the location of the object. The proposed context information model which is able to exhibit various spatial context and recognizes complex spatial context through the existing GIS. This model shows that it can adapt to a large scale outdoor context-aware applications such as air pollution and prevention of disasters as well as various context-aware applications.

• Food Science and Preservation
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• v.15 no.1
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• pp.74-78
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• 2008

Desorption experiments were carried out on soybean (Taegwang) at 5, 15, 25, 35, $45^{\circ}C$ for moisture contents between 6.74 and 28.87%(db). The method employed was to measure the equilibrium relative humidity (ERH) of air in contact with the grain under static conditions, using an electronic hygrometer. The effects of temperature and moisture contents were investigated, and the measured values were fitted to the modified Henderson, the modified Chung-Pfost, the modified Halsey, the modified Oswin and the modified GAB model. The ERHs of soybean under the moiture content of 16.67%(db) decreased with an decrease in moisture content and temperature, but the ERH of the moisture content of 28.87%(db) material decreased with an increase of temperature. The modified GAB model was the best in describing the EMC/ERH of soybean.

• Journal of the Economic Geographical Society of Korea
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• v.12 no.4
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• pp.540-556
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• 2009

The hub and spoke network is a critical network-based infrastructure that is widely applied in current transportation and telecommunications systems, including Internets, air transportation networks and highway systems. This main idea of hub location models is to construct a network system which achieves the economy of scale of flows. The main purpose of this study is to introduce new hub location problems that take into account network reliability. Two standard models based on assignment schemes are proposed, and a minimum threshold model is provided as an extension in terms of hub network design. The reliability and interaction potentials of 15 nodes in the U.S. are used to examine model behaviors. According to the type of models and reliability, hubs, and minimum threshold levels, relationships among the flow economy of scale, network costs, and network resiliency are analyzed.