• 대한전기학회논문지:시스템및제어부문D
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• 제54권9호
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• pp.539-546
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• 2005

This paper describes a method of building the probability grid map for an autonomous mobile robot using the ultrasonic DAF(data association filter). The DAF, which evaluates the association of each data with the rest and removes the data affected by the specular reflection effect, can improve the reliability of the data for the Probability grid map. This method is based on the evaluation of possibility that the acquired data are all from the same object. Namely, the data from specular reflection have very few possibilities of detecting the same object, so that they are excluded from the data cluster during the process of the DAF. Therefore, the uncertain data corrupted by the specular reflection and/or multi-path effect, are not used to update the probability map, and hence building a good quality of a grid map is possible even in a specular environment. In order to verify the effectiveness of the DAF, it was applied to the Bayesian model and the orientation probability model which are the typical ones of a grid map. We demonstrate the experimental results using a real mobile robot in the real world.

• The Journal of Asian Finance, Economics and Business
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• 제8권2호
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• pp.1157-1168
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• 2021

Hotels drive the growth and development of tourism. Despite their important role, many hotels are small and medium-sized firms (SME) that are struggling to survive against fierce competition. Experts agree that strategic planning is vital for SME survival, but it is not wholly applicable for SME managers. Meanwhile, Mintzberg's concept of crafting strategy offers a more productive insight into SME strategic planning, but its abstract nature has historically discouraged empirical research on its practical benefits. This study will be the first to empirically explore the operationalization of Mintzberg's crafting strategy characteristics, and analyze its influence on organizational learning using structural equation model. Using a sample of 50 hotels in Bali, Indonesia, this study reveals that managing pattern and stability, detecting discontinuity, and knowing the business have a positive but weak effect, whereas reconciling change and continuity proves to have a positive and significantly strong effect on organizational learning. This study has bridged the gap between the abstract concepts of crafting strategy, which is a potentially better approach for SMEs, with daily operational practices. This study also proves that Mintzberg's approach can be used to predict organizational learning. This relationship is crucial since previous studies concluded that organizational learning improves company performance.

• Journal of information and communication convergence engineering
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• 제1권3호
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• pp.150-156
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• 2003

This paper explored the use of an algorithm for the data mining and method in handling missing data which had generated enhanced association patterns observed using the data illustrated here. The evaluations showed that more association patterns are generated in the second analysis which suggests more meaningful rules than in the first situation. It showed that the model offer more precise and important association rules that is more valuable when applied for business decision making. With the discovery of accurate association rules or business patterns, strategies could be efficiently planned out and implemented to improve marketing schemes. This investigation gives rise to a number of interesting issues that could be explored further like the effect of outliers and missing data for detecting fraud and devious database entries.

• Journal of the Korean Statistical Society
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• 제29권1호
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• pp.81-94
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• 2000

For the balanced variance component model, sometimes intraclass correlation coefficient is of interest. If there is little information about the parameter, then the reference prior(Berger and Bernardo, 1992) is widely used. Pettit nd Young(1990) considered a measrue of the effect of a single observation on a logarithmic Bayes factor. However, under such a reference prior, the Bayes factor depends on the ratio of unspecified constants. In order to discard this problem, influence diagnostic measures using the intrinsic Bayes factor(Berger and Pericchi, 1996) is presented. Finally, one simulated dataset is provided which illustrates the methodology with appropriate simulation based computational formulas. In order to overcome the difficult Bayesian computation, MCMC methods, such as Gibbs sampler(Gelfand and Smith, 1990) and Metropolis algorithm, are empolyed.

• Journal of Welding and Joining
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• 제30권6호
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• pp.80-85
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• 2012

Fatigue cracks in structural components are the most common cause of structural failure when exposed to fatigue loading. In this respect, fatigue crack detection and structural health assessment are very important. Currently, various smart materials are used for detecting fatigue crack and measurement of SIFs(Stress Intensity Factors). So, this paper presented a measurement of SIFs using MFC(Micro Fiber Composite) sensor which is the one of the smart material. MFC sensor is more flexible, durable and reliable than other smart materials. The SIFs of Mode I(K I) as well as Mode II(K II) based on the piezoelectric constitutive law and fracture mechanics are calculated. In this study, the SIF values measured by MFC sensors are compared with the theoretical results.

• 전력전자학회논문지
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• 제21권5호
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• pp.449-452
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• 2016

This paper presents a simplified analysis on the rotor position detection error in sensorless interior permanent magnet brushless DC motor (BLDCM) drives, wherein terminal voltage sensing based on the back-electromotive force (back-EMF) zero-crossing point detecting circuitry is employed. The effect of a rotor saliency on the back-EMF's zero-crossing point detection is analyzed using the extended EMF-based voltage equation of the interior permanent BLDCM in a stationary reference frame, and thus the overall analysis is considerably simplified compared to the conventional one. Simulation results are provided to verify the effectiveness of the proposed method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 추계학술대회 논문집 학회본부
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• pp.73-77
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• 1990

In this paper we describe the solid-state ac-circuit breaker which has the characteristic of both a half cycle circuit breaker and a current limiting circuit breaker. This circuit breaker has a current limiting resistor in order to surprises the fault current to a certain level and discharge the energe included in circuit inductor. We explain the effect of circuit parameter on transient phenomena of switch device by using EMTP and finally design the control circuit consisted synchronous closing circuit, over- current detecting circuit and sensing circuit of rate of rise of fault current.

• 센서학회지
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• 제23권4호
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• pp.217-223
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• 2014

Nerve agents are major chemical warfare agents with the "G series" and "V series" being the most widely known because of their lethal effect. Although not conspicuously used in major wars, the potential detrimental impact on modern society had been revealed from the sarin terror attack on Tokyo subway, which affected thousands of people. In this mini-review, major nerve agents of the "G series" and "V series" have been described along with various types of their detection methods. The physical properties and hydrolysis mechanisms of the major nerve agents are discussed since these are important factors to be considered in choosing detection methods, and specifying the procedures for sample preparations in order to enhance detection precision. Various types of extraction methods, including liquid-phase, solid-phase, gas-phase and solid-phase microextraction (SPME), are described. Recent development in the use of gas sensors for detecting nerve agents is also summarized.

• 오토저널
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• 제4권3호
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• pp.48-55
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• 1982

In the present the strain gauge type torque transducers consist of solid shaft as sensor, slip ring, brush and bridge circuit as detecting circuit. So in the case of measuring the low-capacity torque, the error caused by technical mistake in mounting stain gauge on the small sensor and especially by contact resistance between slip ring and brush takes place more than the large sensor. Therefore in this study constant voltage in order to have no effect of contact resistance is supplied to the hollow shaft and Schrobron Bridge Circuit. Through the experiment good results were obtained as follows; linearity, hysterisis and zero drift as static characteristics is within 1% F.S respectively. Also when loading, zero drift is about 2% F.S.

• 대한수의학회지
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• 제42권3호
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• pp.377-382
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• 2002

Bovine piroplasmosis caused by Theileria sergenti is a major cause of economic loss in livestock industry. Five cattle infected with Theileria sergenti showing severe and fatal anemia, confirmed by indirect immunofluorescent assay(IFA), were used in this study. Four cattle were treated with diminazene aceturate and one was not treated as the control. The therapeutic effect of diminazene aceturate against Theileria sergenti infection was monitored by detecting the 32kDa polypeptide specific for Theileria sergenti by the western blotting with both polyclonal and monoclonal antibodies. The 32kDa polypeptide detected at the beginning of diminazene aceturate treatment was not detectable after the treatment. It is postulated that the detection of the 32kDa polypeptide specific for Theileria sergenti may be a good tool for the diagnosis and monitoring the treatment progress of Theileria sergenti infection.