• IE interfaces
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• v.20 no.3
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• pp.288-297
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• 2007

Success of semiconductor/LCD industry depends on its yield and quality of product. For the purpose, FDC (Fault Detection and Classification) system is used to diagnose fault state in main manufacturing processes by monitoring time series data collected by equipment sensors which represent various conditions of the equipment. The data set is segmented at the start and end of each product lot processing by a trigger event module. However, in practice, segmented sensor data usually have the features of data asynchronization such as different start points, end points, and data lengths. Due to the asynchronization problem, false alarm (type I error) and missed alarm (type II error) occur frequently. In this paper, we propose a robust process fault detection system by integrating a process event detection method and a similarity measuring method based on dynamic time warping algorithm. An experiment shows that the proposed system is able to recognize abnormal condition correctly under the asynchronous data situation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.7
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• pp.3018-3040
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• 2018

The mobility model is one of the most important factors that impacts the evaluation of any transportation vehicular networking protocols via simulations. However, to obtain a realistic mobility model in the dynamic urban environment is a very challenging task. Several studies extract mobility models from large-scale real data sets (mostly taxi GPS data) in recent years, but they do not consider the statuses of taxi, which is an important factor affected taxi's mobility. In this paper, we discover three simple observations related to the taxi statuses via mining of real taxi trajectories: (1) the behavior of taxi will be influenced by the statuses, (2) the macroscopic movement is related with different geographic features in corresponding status, and (3) the taxi load/drop events are varied with time period. Based on these three observations, a novel taxi mobility model (T-START) is proposed with respect to taxi statuses, geographic region and time period. The simulation results illustrate that proposed mobility model has a good approximation with reality in trajectory samples and distribution of nodes in four typical time periods.

• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.5
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• pp.568-576
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• 2017

With an increase in the usage of LNG, there is a heightened interest about its safety aspects regarding the explosion of LNG carrier tank. The need for a cryogenic explosion-proof camera has increased. The camera has to work in cryogenic environment (below $-160^{\circ}C$) in LNG carrier. This study conducted design and heat transfer analysis of cryogenic camera to secure working time in limitation of heat source. The design with gap width of double pane windows was conducted based on simple vertical cavity model to insulate from cryogenic environment. The optimal gap width was 12.5 mm. For effective analysis considering convection within the camera, equivalent thermal conductivity method was adopted with ABAQUS. The working time of the camera predicted was over 10 h at warm-start condition. In cold-start condition, it required about 5 h of pre-warming time to work. The results of analysis were compared with the ones of the actual cryogenic test.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2910-2915
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• 2008

This paper was investigated the behaviors of the engine and combustion phenomena for various LPG compositions in the semi-return type system, which is not recircurated to LPG tank through furl rail, applied LPi engine during a cold idle condition and including a cold start of the engine. Cyclic HC and NOx emissions were measured at exhaust port to examine their formation mechanical and reduction mechanical with fast response gas analyzers. Various ignition timing is experimented to study the characteristics of combustion phenomena, HC/NOx emissions during fast idle. Also, this study was investigated start delay time, cylinder pressure, HC/NOx emissions, Mass Fraction Burned, starting time to evaluate performance of transient cold startability. Compared to the return type system, the semi-return type system have advantages in point of production cost and equivalent performance of engine starting time and pressure settling time.

• Journal of the Korean Institute of Intelligent Systems
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• v.6 no.3
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• pp.51-62
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• 1996

Electro sensitive traffic system can not consider passenger car unit, so it causes start up delay time and passenger waiting time. In this paper, it antecedently creates passenger car unit at the bottom intersection using neural network. But, sometimes it can make mistakes due to changes in car weight, car speed, and passing area. Therefore, it consequently reduces the car waiting time and start-up delay time using fuzzy control of feed-back data. Moreover, to prevent spillback, it can adapt control even though upper traffic intersection has a different saturation rate, road length, road slope and road width.

• Proceedings of the Korean Nuclear Society Conference
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• 2003.10a
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• pp.233.1-233.1
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• 2003

• Proceedings of the Korean Society of Rheology Conference
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• 2001.06a
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• pp.73-76
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• 2001

• Journal of Distribution Science
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• v.11 no.10
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• pp.37-45
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• 2013

Purpose - Appropriate response to the fast changing economic environment determines SMEs' competiveness in the era of globalization and open market and, therefore, government policies to strengthen SME's competitiveness will be very important in the future. It is time to investigate the element of strategic orientation that is necessary for strengthening the competitiveness of SMEs, and its effect on the success of a business start-up. This study analyzes the network orientation in addition to existing strategic orientation, and focuses on price and quality management capability as mediators for strategic orientation and outcomes of business start-ups. Research design/data/methodology - The orientations of technology-based business founders were classified into market, technology, network, and entrepreneurial orientation. We then investigated the effect of these orientations on product price and quality management capability, as well as the influence of price and quality management capability on the outcome of a business start-up. This study is based on the nation-wide survey of the founders and members of technology-based business establishments. The survey was administered to 300 selected companies via email for a period of one month, at the end of which 175 companies replied with valid answers. Further, for effective and objective research, we used SPSS 14.0 and Amos 7.0 for structural equation modeling assumptions and hypothesis verification. Results - Except for entrepreneurial orientation, the other three orientations, namely, technology, market, and network orientations, affect the price management capability according to our results. The price management capability relates significantly with the sales and customer satisfaction. Especially, technology orientation is the core competency of start-ups that affects price and quality management capabilities. However, technology and entrepreneurial orientation do not influence the outcome of business start-ups, but affect their quality management capabilities. Conclusions - This study confirms that the strategic orientation affects product price as well as quality management capabilities, to introduce new products and achieve successful outcomes. In conclusion, new business founders face the dilemma of trade-off between price and quality in the planning stage of new product development. In particular, price management capability directly affects the outcome. Therefore, price management is more important for a successful start-up than quality management. Especially, during the initial stages of starting up a new business, price management capability entails following the market-leading company, or price penetration strategy. In this stage, price management is dependent on the information from outside rather than on the founder's decision, and it directly affects sales performance and customer satisfaction. In contrast, quality management capability is directly related to the technology capability and market experience of founders. In this case, subjective and proactive decision making is required for differentiation and development of demand in the niche market, which does not directly influence the sales performance and customer satisfaction.

• Journal of IKEEE
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• v.22 no.2
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• pp.258-265
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• 2018

This paper proposes an algorithm for reducing the starting current when the single-phase induction motor starts and analyzes its operation. Generally, the single-phase induction motors require several starters to generate the starting torque due to their structural characteristics. In this paper, a capacitor-start / capacitor-run method of the single-phase induction motor is basically adopted. This conventional method is efficient and has a large starting torque, but it generates about 5 ~ 6 times of inrush current at startup. As a result, the freezer starting device and peripheral devices are damaged and life time may be reduced. To reduce the inrush current, the current control algorithm based on the virtual dq model is presented to control the starting current. In addition, it validates the proposed algorithm through experiments to smooth transit from start-up operation to the rated operating region.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.12
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• pp.224-232
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• 2009

Power plant start-up is a complicate process involving hundreds of operations that should be performed either automatically or manually. Several major operations should be proceeded in parallel and each major operation is again broken down into detailed operations that must be carried out in a strict sequence. Even though most of the operations are automated, still substantial portions of the operations are carried out manually and the operational status should be monitored by the crew members, which are quite stressful tasks to be performed in real time. In this paper, a data structure called an Event Sequence Monitoring Graph(ESMG) is proposed for monitoring a sequence of events involved in the power plant start-up process. The ESMG is currently being applied to a thermal power plant with a rated output of 500MW. An application example is shown with the boiler feed water pump system start-up process, which exhibits a good potential for future applications.