• Journal of Electrical Engineering and Technology
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• 제12권6호
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• pp.2106-2117
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• 2017

An effective statistical feature extraction approach of data sampling of fault in the combined transmission system is presented in this paper. The proposed algorithm leads to high accuracy at minimum cost to predict fault location and fault type classification. This algorithm requires impedance measurement data from one end of the transmission line. Modal decomposition is used to extract positive sequence impedance. Then, the fault signal is decomposed by using discrete wavelet transform. Statistical sampling is used to extract appropriate fault features as benchmark of decomposed signal to train classifier. Support Vector Machine (SVM) is used to illustrate the performance of statistical sampling performance. The overall time of sampling is not exceeding 1 1/4 cycles, taking into account the interval time. The proposed method takes two steps of sampling. The first step takes 3/4 cycle of during-fault and the second step takes 1/4 cycle of post fault impedance. The interval time between the two steps is assumed to be 1/4 cycle. Extensive studies using MATLAB software show accurate fault location estimation and fault type classification of the proposed method. The classifier result is presented and compared with well-established travelling wave methods and the performance of the algorithms are analyzed and discussed.

• 방사성폐기물학회지
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• 제15권2호
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• pp.173-180
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• 2017

본 연구에서는 한국원자력연구원의 핵연료가공시설 굴뚝 내에서 9곳의 시료채취 위치를 선정하여 ANSI/HPS N13.1-1999 지침에서 제시하는 기준에 따라 그 적절성을 평가하였다. 유체를 포함한 다중물리 해석 소프트웨어인 COMSOL을 활용하여 유동교란 지점으로부터 굴뚝 직경의 배수 높이 위치(L/D) 단면에서의 속도분포, 유동각 및 $10{\mu}m$ 크기의 입자분포 등의 항목에 대하여 기준만족 여부를 평가하였다. 평가 결과, 5 L/D 이상에서 속도분포에 대한 기준을 만족했으며, 평균 유동각에 대한 기준은 모든 위치에서 만족했다. 입자분포에 대한 기준은 5 L/D 와 9 L/D 에서 만족하였으나, 그 분포가 일부에서 기준을 만족하지 못하였다. 균일한 입자분포를 얻기 위한 방법으로 굴뚝 내 정적 혼합장치(static mixer)와 둘레링(perimeter ring)을 추가하는 것을 제안하고, 이에 대한 평가를 수행하였다. 정적 혼합장치를 추가한 경우에는 5-10 L/D, 둘레링을 추가한 경우에는 5 L/D 및 7-10 L/D 에서 입자분포에 대한 기준을 만족하였다. 보완을 위하여 추가한 2 가지 조건에서, 입자분포에 대한 기준을 만족하는 지점은 속도분포 및 평균 유동각에 대한 기준 역시 만족하고 있음을 확인하였다. 본 연구에서 사용한 방법은 신규시설뿐만 아니라, 현장입증시험 수행이 어려운 운영중인 시설에 대하여 시료채취 위치의 적절성을 평가하기 위한 방법으로 활용될 수 있다.

• Journal of the Korean Data and Information Science Society
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• 제15권1호
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• pp.227-237
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• 2004

In this paper we presented a Bayesian inference approach for estimating the location and scale parameters of the lognormal distribution using iterative Gibbs sampling algorithm. We also presented estimation of location parameter by two non iterative methods, importance sampling and weighted bootstrap assuming scale parameter as known. The estimates by non iterative techniques do not depend on the specification of hyper parameters which is optimal from the Bayesian point of view. The estimates obtained by more sophisticated Gibbs sampler vary slightly with the choices of hyper parameters. The objective of this paper is to illustrate these tools in a simpler setup which may be essential in more complicated situations.

• The Journal of Asian Finance, Economics and Business
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• 제8권3호
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• pp.1327-1338
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• 2021

This study aims to examine how experiential marketing and location influence customer loyalty mediated by customer satisfaction. This study's population was Cafe Excelso Rinjani customers in Semarang, Indonesia. The sampling employed a purposive sampling technique, with the following criteria: customers who visited and enjoyed Cafe Excelso Rinjani and aged more than 17 years. Data analysis used multiple regression analysis, and a single test was utilized to test for mediation. The results revealed that experiential marketing positively and significantly affected customers satisfaction. It showed that the better the experiential marketing was done, the more customer satisfaction would be. Location positively and significantly influenced customer satisfaction. It indicated that the more strategic the location, the more customer satisfaction increased. Meanwhile, experiential marketing had no impact on customer loyalty. Location positively and significantly affected customer loyalty at Cafe Excelso Rinjani Semarang. It denoted that the more strategic the location, the more customer loyalty increased. Besides, customer satisfaction had a positive and significant effect on customer loyalty. It signified that, when customer satisfaction increased, customer loyalty would increase. Finally, customer satisfaction perfectly mediated the influence of experiential marketing on customer loyalty, and customer satisfaction mediated the effect of location on customer loyalty.

• The Journal of Asian Finance, Economics and Business
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• 제7권4호
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• pp.235-245
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• 2020

The study seeks to identify factors affecting the choice of a university by first-year Business Administration students in Vietnam. Probability sampling is using Stratified sampling of 500 students from five private universities in Ho Chi Minh City surveyed by convenience sampling. This paper employs mixed research methods - measuring Cronbach's Alpha, EFA, Regression and using PATH model - to test the hypotheses of the research model. The results of the study identify five factors: Prestige, Geographical location, Facilities, Attractiveness of the field and Media. All these factors have a positive influence on the standing of the university brand. It means that the higher the Prestige, Geographical location, Facilities, Attractiveness of the field and Media, the higher the university brand. The results indicate that Geographical location is the most influential factor to enhance the private university's brand. Bringing Geographical location is, thus, advisable to enhance a university standing. The brand plays a determining role in students' trust when selecting a university. Media is still the top concern of new students when they choose to study at a university. Media still remains an important consideration for new students when choosing a university. So, this factor should be utilized by universities to enhance their attractiveness.

• Communications for Statistical Applications and Methods
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• 제9권1호
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• pp.221-227
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• 2002

The concept of pivot has been widely used in various classical inferences. In this paper, it is proved by use of pivotal quantities that the Bayesian inferences can be arrived at the same results of classical inferences for the location-scale parameters models under the assumption of non-informative prior distributions. Some theorems are proposed in which the posterior distribution and the sampling distribution of a pivotal quantity coincide. The theorems are applied illustratively to some statistical models.

• 한국토양환경학회지
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• 제3권1호
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• pp.3-9
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• 1998

본 연구는 휘발성 유기 화합물로 오염된 가솔린 지역에서 soil-gas의 분석결과로부터 오염도를 유추하는 기법에 대하여 서술 하였다. Soil-gas의 채취방법으로는 펌프를 이용한 1)grab sampling법과 흡착제 trap을 사용한 2)passive sampling법이 있다. Grab sampling법은 특정시간에 특정장소에서의 오염도를 보여주며, 반면에 passive sampling법은 특정위치에서 시간에 따른 오염도의 변화를 보여 준다. Soil-gas의 분석은 1)PID나 FID와 같은 작은 검지기에 의해서 총괄 탄화수소량을 측정할수도 있고 2)기체농도에 따라서 색깔이 변하는 지시약이 채워진 기체검지기 튜브를 사용할수도 있으며 3)여러가지 화합물을 한 번에 분석할수 있는 이동형 GC를 사용할수도 있다. Soil-gas를 이용한 측정법은 매우 값싸며 세밀한 정밀조사를 하기 위한 전단계에서 사용할 수 있는 유용한 방법으로 추천할만하다 하겠다.

• Journal of Biosystems Engineering
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• 제40권2호
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• pp.115-123
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• 2015

Purpose: A sampling scheme may significantly affect the accuracy of a sensor. This study was conducted to investigate the effects of sampling point locations on optical reflectance measurements of Chinese cabbage and kale plant leaves. Methods: Variability and similarity of multiple measurements for different parts of the leaves were compared. Results: The results indicate that the variability between the average and individual reflectance spectra was smaller for the blade part than for the vein part. Furthermore, the reflectance for the blade part over the upper leaf area was greater and more stable than those for the other parts for both the cabbage and kale leaf samples. Conclusions: The results provide guidelines for optical reflectance measurements of Chinese cabbage and kale plants. The effects of the number of sampling points, the number of leaves, and the relationships between optical reflectance and leaf components remain to be investigated in the future.

• Bulletin of the Korean Chemical Society
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• 제30권5호
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• pp.1077-1079
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• 2009

To minimize the variance in the quantification of solid-state phases in powder samples, gently placing polycrystalline samples one next to another directly in a sample holder is better than trying to mix them homogeneously prior to transferring to a sample holder. However, the solid-state cross polarization-magic angle spinning (CP-MAS) nuclear magnetic resonance (NMR) spectroscopy results demonstrated that it is essential in this sampling method to place all the samples in the location of consistent signal sensitivity. The same sampling method may be employed in other spectroscopic quantification techniques of solid-state phases if the method to limit the sample to the location with uniform signal sensitivity in the sample holder is adapted to each technique.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권2호
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• pp.600-619
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• 2015

We propose a cost-efficient hybrid algorithm for online location updates that efficiently combines feature point detection with the online trajectory-based sampling algorithm. Our algorithm is designed to minimize the average trajectory error with the minimal number of sample points. The algorithm is composed of 3 steps. First, we choose corner points from the map as sample points because they will most likely cause fewer trajectory errors. By employing the online trajectory sampling algorithm as the second step, our algorithm detects several missing and important sample points to prevent unwanted trajectory errors. The final step improves cost efficiency by eliminating redundant sample points on straight paths. We evaluate the proposed algorithm with real GPS trajectory data for various bus routes and compare our algorithm with the existing one. Simulation results show that our algorithm decreases the average trajectory error 28% compared to the existing one. In terms of cost efficiency, simulation results show that our algorithm is 29% more cost efficient than the existing one with real GPS trajectory data.